# PS3.18

## DICOM PS3.18 2019c - Web Services

### DICOM Standards Committee

Copyright © 2019 NEMA

A DICOM® publication

List of Figures

8.1-1. Interaction Diagram for Transactions
8.6-1. Mapping between IOD and HTTP message parts

List of Tables

5.1-1. ABNF for Common Syntactic Values
5.2-1. Request Header Fields
5.2-2. Response Header Fields
8.3.1-1. ABNF for Query Parameter
8.3.2-1. Query Parameter Usage
8.3.2-2. Example Query Parameter Table
8.3.4-1. Query Parameter Syntax
8.3.5-1. Retrieve Rendered Query Parameters
8.3.5-2. Thumbnail Query Parameters
8.4.1-1. Content Negotiation Header Fields
8.4.2-1. Content Representation Header Fields
8.4.3-1. Payload Header Fields
8.5-1. Status Code Meaning
8.6.1-1. Multipart Header Fields
8.7.2-1. Resource Categories
8.7.3-1. Definition of Media Type Requirement
8.7.3-2. Transfer Syntax UIDs for application/dicom Media Types
8.7.3-3. Media Types for Metadata
8.7.3-4. Transfer Syntax UIDs for Uncompressed Data in Bulkdata
8.7.3-5. Media Types and Transfer Syntax UIDs for Compressed Data in Bulkdata
8.7.4-1. Rendered Media Types by Resource Category
8.7.8-1. Media Type QValue Example
8.9.1-1. Request Header Fields
8.9.3-1. Status Code Meaning
8.9.3-2. Response Header Fields
8.10.3-1. Notification Sub-System Transactions
8.10.4-1. Request Header Fields
8.10.4-2. Status Code Meaning
8.10.4-3. Response Header Fields
9.1.2-1. Mandatory Query Parameters
9.1.2-2. Optional Query Parameters
9.4.1-1. Optional Query Parameters
9.4.1-2. Request Header Fields
9.4.3-1. Status Code Meaning
9.4.3-2. Response Header Fields
9.5.1-1. Query Parameters
9.5.1-2. Request Header Fields
9.5.3-1. Status Code Meaning
9.5.3-2. Response Header Fields
10.1-1. Resources and Descriptions
10.1.2-1. Common Query Parameters
10.3-1. Studies Service Transactions
10.3-2. Resources by Transaction
10.4.1-1. Retrieve Transaction DICOM Resources
10.4.1-2. Retrieve Transaction Metadata Resources
10.4.1-3. Retrieve Transaction Rendered Resources
10.4.1-4. Retrieve Transaction Thumbnail Resources
10.4.1-5. Query Parameters by Resource
10.4.1-6. Request Header Fields
10.4.3-1. Status Code Meaning
10.4.3-2. Response Header Fields
10.4.3-3. Resource Media Types
10.4.4-1. Default, Required, and Optional Media Types
10.5.1-1. Store Transaction DICOM Resources
10.5.1-2. Request Header Fields
10.5.2-1. Media Type Transformation to Transfer Syntaxes
10.5.3-1. Status Code Meaning
10.5.3-2. Response Header Fields
10.5.4-1. Default, Required, and Optional Media Types
10.6.1-1. Search Transaction Resources
10.6.1-2. Search Resource Descriptions
10.6.1-3. Search Key Types
10.6.1-4. Required IE Levels by Resource
10.6.1-5. Required Matching Attributes
10.6.1-6. Request Header Fields
10.6.3-1. Status Code Meaning
10.6.3-2. Response Header Fields
10.6.3-3. Study Resource Search Response Payload
10.6.3-4. Series Resources Search Response Payload
10.6.3-5. Instance Resources Search Response Payload
10.6.4-1. Default, Required, and Optional Media Types
11.1.1-1. Resources, URI Templates and Descriptions
11.1.1-2. Correspondence between RESTful and DIMSE Terminology
11.1.2-1. Common Query Parameters
11.1.3-1. Default, Required, and Optional Media Types
11.3-1. Worklist Service Methods and Resource Templates
11.4.1-1. Create Transaction Resources
11.4.1-3. Request Header Fields
11.4.3-1. Status Code Meaning
11.4.3-2. Response Header Fields
11.5.1-1. Request Header Fields
11.5.3-1. Status Code Meaning
11.5.3-2. Response Header Fields
11.6.1-1. Request Header Fields
11.6.3-1. Status Code Meaning
11.6.3-2. Response Header Fields
11.7.1-1. Request Header Fields
11.7.3-1. Status Code Meaning
11.7.3-2. Response Header Fields
11.8.1-1. Request Header Fields
11.8.3-1. Status Code Meaning
11.8.3-2. Response Header Fields
11.9.1-1. Request Header Fields
11.9.3-1. Status Code Meaning
11.9.3-2. Response Header Fields
11.10.1-1. Subscribe Transaction Resources
11.10.1-2. uery Parameters by Resource
11.10.3-1. Status Code Meaning
11.10.3-2. Response Header Fields
11.11.1-1. Unsubscribe Transaction Resources
11.11.3-1. Status Code Meaning
11.11.3-2. Response Header Fields
11.12.1-1. Unsubscribe Transaction Resources
11.12.3-1. Status Code Meaning
11.12.3-2. Response Header Fields
12.1.1-1. Resource Categories, URI Templates and Descriptions
12.1.2-1. Common Query Parameters
12.1.3-1. Default, Required, and Optional Media Types
12.2-1. Required and Optional Transactions
12.3-1. NPI Service Transactions
12.3-2. Resources by Transaction
12.4.1-1. Retrieve Transaction Resources
12.4.1-2. Request Header Fields
12.4.3-1. Status Code Meaning
12.4.3-2. Response Header Fields
12.5.1-1. Store Transaction Resources
12.5.1-2. Request Header Fields
12.5.3-1. Status Code Meaning
12.5.3-2. Response Header Fields
12.6.1-1. Search Transaction Resources
12.6.1-2. NPI Resource Search Attributes
12.6.1-3. Request Header Fields
12.6.3-1. Status Code Meaning
12.6.3-2. Response Header Fields
D-1. IANA Character Set Mapping
F.2.3-1. DICOM VR to JSON Data Type Mapping
F.3.1-1. XML to JSON Mapping
H-1. Resources and Methods
I.1-1. Store Instances Response Module Attributes
I.2-1. Store Instances Response Warning Reason Values
I.2-2. Store Instances Response Failure Reason Values

# Notice and Disclaimer

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# Foreword

This DICOM Standard was developed according to the procedures of the DICOM Standards Committee.

The DICOM Standard is structured as a multi-part document using the guidelines established in [ISO/IEC Directives, Part 2].

PS3.1 should be used as the base reference for the current parts of this Standard.

DICOM® is the registered trademark of the National Electrical Manufacturers Association for its standards publications relating to digital communications of medical information, all rights reserved.

HL7® is the registered trademark of Health Level Seven International, all rights reserved.

# 1 Scope

PS3.18 specifies web services (using the HTTP family of protocols) for managing and distributing DICOM (Digital Imaging and Communications in Medicine) Information Objects, such as medical images, annotations, reports, etc. to healthcare organizations, providers, and patients. The term DICOMweb™ is used to designate the RESTful Web Services described here.

Security considerations, including access control, authorization, and auditing are beyond the scope of PS3.18. Refer to PS3.15.

# 2 Normative References

The following normative documents contain provisions that, through reference in this text, constitute provisions of this Part of DICOM. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Part of DICOM are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.

## 2.1 International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC)

[ISO/IEC Directives, Part 2] ISO/IEC. 2016/05. 7.0. Rules for the structure and drafting of International Standards. http://www.iec.ch/members_experts/refdocs/iec/isoiecdir-2%7Bed7.0%7Den.pdf .

[ISO/IEC 2022] ISO/IEC. 1994. Information technology - Character code structure and extension techniques.

[ISO 7498-1] ISO. 1994. Information Processing Systems - Open Systems Interconnection - Basic Reference Model.

[ISO/IEC 10918-1] ISO/IEC. 1994. JPEG Standard for digital compression and encoding of continuous-tone still images. Part 1 - Requirements and implementation guidelines.

[ISO/IEC 10646] ISO/IEC. 2003. Information Technology - Universal Multiple-Octet Coded Character Set (UCS). ISO/IEC 10646-2003 is the same as Unicode Version 4.0, available at http://unicode.org .

[ISO 15076-1] ISO. 2005. Image technology colour management - Architecture, profile format, and data structure. Also available as ICC.1:2004-10 (Profile version 4.2.0.0), International Color Consortium, available at http://www.color.org/v4spec.xalter .

[ISO/IEC 15444-1] ISO/IEC. 2004. JPEG 2000 Image Coding System.

[ISO/IEC 15444-2] ISO/IEC. 2004. JPEG 2000 Image Coding System: Extensions.

[ISO 15948] ISO. 2003. Information technology -- Computer graphics and image processing -- Portable Network Graphics (PNG): Functional specification. A Joint ISO/IEC International Standard and W3C Recommendation. Also available at: https://www.w3.org/TR/2003/REC-PNG-20031110/ .

[ISO 22028-2] ISO. 2013. Photography and graphic technology - Extended colour encodings for digital image storage, manipulation and interchange - Part 2: Reference output medium metric RGB colour image encoding (ROMM RGB). http://www.iso.org/iso/catalogue_detail.htm?csnumber=56591 .

[IEC 61966-2.1] IEC. 1999. Ed 1.0 as amended by Amendment A1:2003. Multimedia systems and equipment - colour measurement and management - Part 2.1: colour management - Default RGB colour space - sRGB.

## 2.2 Internet Engineering Task Force (IETF) and Internet Assigned Names Authority (IANA)

[IANA Character Sets] IANA. . Character Sets. http://www.iana.org/assignments/character-sets/character-sets.xhtml .

[IANA HTTP Status Code Registry] IANA. . Hypertext Transfer Protocol (HTTP) Status Code Registry. http://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml .

[IANA Media Types] IANA. . Media Types. http://www.iana.org/assignments/media-types/media-types.xhtml .

[RFC822] IETF. August 1982. Standard for ARPA Internet Text Messages. http://tools.ietf.org/html/rfc822 .

[RFC1945] IETF. May 1996. Hypertext Transfer Protocol Version 1.0 (HTTP/1.0) . http://tools.ietf.org/html/rfc1945 .

[RFC2045] IETF. November 1996. Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies. http://tools.ietf.org/html/rfc2045 .

[RFC2046] IETF. November 1996. Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types. http://tools.ietf.org/html/rfc2046 .

[RFC2387] IETF. August 1998. The MIME Multipart/Related Content-type. http://tools.ietf.org/html/rfc2387 .

[RFC2818] IETF. May 2000. HTTP Over TLS. http://tools.ietf.org/html/rfc2818 .

[RFC2978] IETF. October 2000. IANA Charset Registration Procedures. http://tools.ietf.org/html/rfc2978 .

[RFC3240] IETF. February 2002. Digital Imaging and Communications in Medicine (DICOM) - Application/dicom MIME Sub-type Registration. http://tools.ietf.org/html/rfc3240 .

[RFC3536] IETF. May 2003. Terminology Used in Internationalization in the IETF. http://tools.ietf.org/html/rfc3536 .

[RFC3745] IETF. April 2004. MIME Type Registrations for JPEG 2000 (ISO/IEC 15444). http://tools.ietf.org/html/rfc3745 .

[RFC3986] IETF. Uniform Resource Identifiers (URI): Generic Syntax. http://tools.ietf.org/html/rfc3986 .

[RFC_4337] IETF. March 2006. MIME Type Registration for MPEG-4. http://tools.ietf.org/html/rfc4337 .

[RFC4627] IETF. July 2006. The application/json Media Type for JavaScript Object Notation (JSON). http://tools.ietf.org/html/rfc4627 .

[RFC4648] IETF. October 2006. The Base16, Base32, and Base64 Data Encodings. http://tools.ietf.org/html/rfc4648 .

[RFC5234] IETF. January 2008. Augmented BNF for Syntax Specifications: ABNF. http://tools.ietf.org/html/rfc5234 .

[RFC6365] IETF. September 2011. Terminology Used in Internationalization in the IETF. http://tools.ietf.org/html/rfc6365 .

[RFC6338] IETF. August 2011. Definition of a Uniform Resource Name (URN) Namespace for the Schema for Academia (SCHAC). http://tools.ietf.org/html/rfc6338 .

[RFC6455] IETF. December 2011. The WebSocket Protocol. http://tools.ietf.org/html/rfc6455 .

[RFC6570] IETF. March 2012. URI Template. http://tools.ietf.org/html/rfc6570 .

[RFC6838] IETF. January 2013. Media Type Specifications and Registration Procedures. http://tools.ietf.org/html/rfc6838 .

[RFC7159] IETF. March 2014. The JavaScript Object Notation (JSON) Data Interchange Format. http://tools.ietf.org/html/rfc7159 .

[RFC7230] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing. http://tools.ietf.org/html/rfc7230 .

[RFC7231] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content. http://tools.ietf.org/html/rfc7231 .

[RFC7232] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests. http://tools.ietf.org/html/rfc7232 .

[RFC7233] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Range Requests. http://tools.ietf.org/html/rfc7233 .

[RFC7234] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Caching. http://tools.ietf.org/html/rfc7234 .

[RFC7235] IETF. June 2014. Hypertext Transfer Protocol (HTTP/1.1): Authentication. http://tools.ietf.org/html/rfc7235 .

[RFC7236] IETF. June 2014. Initial Hypertext Transfer Protocol (HTTP) Authentication Scheme Registrations. http://tools.ietf.org/html/rfc7236 .

[RFC7237] IETF. June 2014. Initial Hypertext Transfer Protocol (HTTP) Method Registrations. http://tools.ietf.org/html/rfc7237 .

[RFC7405] IETF. December 2014. Case-Sensitive String Support in ABNF. http://tools.ietf.org/html/rfc7405 .

[RFC7525] IETF. May 2015. TLS Recommendations. http://tools.ietf.org/html/rfc7525 .

[RFC7540] IETF. May 2015. Hypertext Transfer Protocol Version 2 (HTTP/2). http://tools.ietf.org/html/rfc7540 .

## 2.3 Other References

[Adobe RGB] Adobe Systems Incorporated. 1998. 2005-05. Adobe RGB (1998) Color Image Encoding. http://www.adobe.com/digitalimag/pdfs/AdobeRGB1998.pdf .

[Fielding] Architectural Styles and the Design of Network-based Software Architectures. Fielding. 2000. http://www.ics.uci.edu/~fielding/pubs/dissertation/fielding_dissertation.pdf .

[FHIR Access Denied] HL7. . FHIR Security - Access Denied Response Handling. http://hl7.org/fhir/security.html#AccessDenied .

[IHE RAD TF Vol2] Integrating the Healthcare Enterprise (IHE). Radiology Technical Framework Volume 2. http://www.ihe.net/uploadedFiles/Documents/Radiology/IHE_RAD_TF_Vol2.pdf .

[MNG] Multiple-image Network Graphics. http://www.libpng.org/pub/mng .

[ONC Privacy Security Guide] US Office of the National Coordinator for Health Information Technology (ONC). . Guide to Privacy and Security of Electronic Health Information. http://www.healthit.gov/sites/default/files/pdf/privacy/privacy-and-security-guide.pdf .

[OWASP Information Leakage] Open Web Application Security Project (OWASP). . Top 10 2007 - Information Leakage and Improper Error Handling. http://www.owasp.org/index.php/Top_10_2007-Information_Leakage_and_Improper_Error_Handling .

[WADL] W3C. 31 August 2009. . Member Submission - Web Application Description Language. http://www.w3.org/Submission/wadl/ .

[Wikipedia REST] Wikipedia. . Representational State Transfer. http://en.wikipedia.org/wiki/Representational_state_transfer .

# 3 Definitions

For the purposes of this Part of DICOM, the following terms and definitions apply.

## 3.1 Reference Model Definitions

This Part of the Standard makes use of the following terms defined in [ISO 7498-1]:

Application Entity (AE)

  See [ISO 7498-1].

Real-World Activity

  See [ISO 7498-1].

## 3.2 DICOM Introduction and Overview Definitions

This Part of the Standard makes use of the following terms defined in PS3.1:

Service-Object Pair Class (SOP Class)

  Service-Object Pair Class (SOP Class).

## 3.3 DICOM Message Exchange

This Part of the Standard makes use of the following terms defined in PS3.7:

DICOM Message Service Element (DIMSE)

  DICOM Message Service Element (DIMSE).

## 3.4 DICOM Information Object Definitions

This Part of the Standard makes use of the following terms defined in PS3.3:

Multi-frame Image

  Multi-frame Image.

## 3.5 DICOM Conformance

This Part of the Standard makes use of the following terms defined in PS3.2:

Conformance Statement

  Conformance Statement.

## 3.6 DICOM Data Structures and Encoding

This Part of the Standard makes use of the following terms defined in PS3.5:

Data Element

  Data Element.

Data Element Tag

  Data Element Tag.

Data Set

  Data Set.

Sequence of Items

  Sequence of Items.

Unique Identifier (UID)

  Service-Object Pair Class (SOP Class).

## 3.7 DICOM Service Class Definitions

This Part of the Standard makes use of the following terms defined in PS3.4:

Service-Object Pair Instance (SOP Instance)

  Service-Object Pair Instance (SOP Instance).

## 3.8 HyperText Transfer Protocol (HTTP/HTTPS) Definitions

This Part of the Standard makes use of the following terms defined in [RFC7230] Section 2.1 Client/Server Messaging:

HTTP

  See [RFC7230].

HTTPS

  See [RFC7230].

origin server

  See [RFC7230].

user agent

  See [RFC7230].

## 3.9 Web Services Definitions:

Bulk Data

  An object that contains an octet-stream containing one or more Value Fields (typically containing large data, such as Pixel Data) extracted from a DICOM Dataset. See Metadata.

  ### Note

  1. The octet-stream does not include the Attribute Tag, Value Representation, or Attribute Length.

  2. For the value of a frame of a Pixel Data Attribute encoded in a compressed Transfer Syntax, it does not include the Basic Offset Table and Data Stream Fragment Item tags and lengths.

Bulk Data URI

  A Uniform Resource Identifier that references Bulkdata.

DICOM Object

  An instance of a data object as defined by PS3.3 that has been allocated an unique identifier in the format specified for SOP Instance UID in PS3.3 and has been chosen as an object to be saved securely for some period of time. Within the DICOM Standard, a DICOM Object is typically a Composite Service Object Pair (SOP) Instance.

DICOM Resource

  One or more DICOM Objects that are referenced by a URL.

DIMSE Proxy

  An origin server that responds to DICOM Web Service requests by executing DIMSE transactions to a backend server.

Event Report

  A Dataset containing elements describing an event that occurred on the origin server. See Section 11.12.

Metadata

  A DICOM Dataset where zero or more elements (typically containing large data, such as Pixel Data) have been replaced with Bulkdata URIs.

RESTful Web Service

  A web service is RESTful if it is implemented using the REST architecture and principles. See https://en.wikipedia.org/wiki/Representational_state_transfer.

Service

  When used in this Part of the Standard the term Service means a set of transactions and resources to which those transactions apply.

sRGB

  A standard RGB color space defined in [IEC 61966-2.1].

Status Report

  A Status Report is information contained in a response payload describing warnings or errors related to a request.

Subscriber

  The creator or owner of a Subscription, typically a user agent.

Target URI

  The URI contained in a request message. It designates the resource that is the target of the request.

Thumbnail

  A single frame image that is representative of the content of a DICOM Study, Series, Instance, or Frame. It is encoded in a Rendered Media Type. See Section 8.7.4 and Section 10.4.4.

Transaction

  When used in this Part of the Standard the term Transaction means an HTTP/HTTPS request/response message pair.

UTF-8

  Unicode UTF-8 character set defined in [ISO/IEC 10646].

# 4 Symbols and Abbreviated Terms

ABNF

  Augmented Backus-Naur Form. See [RFC5234] and [RFC7405].

DICOM

  Digital Imaging and Communications in Medicine

HL7

  Health Level Seven

HTML

  HyperText Markup Language

HTTP

  HyperText Transfer Protocol

HTTP/1.1

  Version 1.1 of the HyperText Transfer Protocol

HTTP/2

  Version 2 of the HyperText Transfer Protocol

HTTPS

  HyperText Transfer Protocol Secure

HTTPS/1.1

  Version 1.1 of the HyperText Transfer Protocol Secure

HTTPS/2

  Version 2 of the HyperText Transfer Protocol Secure

IETF

  Internet Engineering Task Force

IHE

  Integrating the Healthcare Enterprise

JSON

  JavaScript Object Notation

QIDO-RS

  Query based on ID for DICOM Objects by RESTful Services

REST

  Representational State Transfer, a web services architecture. See [Wikipedia REST] and [Fielding].

RESTful

  A service implemented using the REST architecture.

SOP

  Service Object Pair

STOW-RS

  STore Over the Web by RESTful Services

UID

  Unique (DICOM) Identifier

UPS-RS

  Unified Procedure Step by RESTful Services

URI

  Uniform Resource Identifier. See [RFC3986].

URL

  Uniform Resource Locator. See [RFC3986].

WADL

  Web Application Description Language

WADO-RS

  Web Access to DICOM Objects by RESTful Services

WADO-URI

  Web Access to DICOM Objects by URI

XML

  eXtensible Markup Language

# 5 Conventions

This section defines conventions used throughout the rest of this Part of the Standard.

## 5.1 Message Syntax

The syntax of the request and response messages for transactions are defined using the ABNF Grammar used in [RFC7230], which is based on the ABNF defined in [RFC5234]. This Part of the Standard also uses the ABNF extensions in [RFC7405], which defines '%s' prefix for denoting case sensitive strings.

The syntax rules defined herein are valid for the US-ASCII character set or character sets that are supersets of US-ASCII, e.g., Unicode UTF-8.

In the ABNF used to define the syntax of messages, the following conventions are used:

1. Syntactic variables are lowercase.

2. Terminal rules are uppercase. For example, 'SP' stands for the US-ASCII space (0x20) literal character, and 'CRLF' stands for the ASCII carriage return (0xD) and line feed (0xA) literal characters.

3. Header Field names are capitalized and quotation marks that denote literal strings for header field names are omitted. The Header Field names are the only capitalized names used in the grammar. See [RFC7231] Section 1.2. For example:

       Accept: media-type CRLF

   is equivalent to

       "Accept:" media-type CRLF

In this Part of the Standard, as with HTTP in general, resources are identified by URIs [RFC3986]. Each service defines the resources it manages, and the URI Templates used to define the structure of the URIs that reference them.

In HTTP RFCs, ABNF rules for obs-text and obs-fold denote "obsolete" grammar rules that appear for historical reasons. These rules are not used in DICOM Web Services syntax definitions.

See Annex A for the Combined ABNF for DICOM Web Services.

### 5.1.1 Common Syntactic Rules For Data Types

Table 5.1-1 defines the syntax of some common rules used in defining data values in this Part of the Standard.

Table 5.1-1. ABNF for Common Syntactic Values

Name | Rule
--- | ---
    int
    = [+ / -] 1*DIGIT
    ; An integer
    uint
    = 1*DIGIT
    ; An unsigned integer
    pos-int
    = NON-ZERO-DIGIT *DIGIT
    ; An integer greater than zero
    decimal
    =int ["." uint] [("E" / "e") int]
    ; a fixed- or floating-point number with at most 16 characters
    string
    = %s 1*QCHAR
    ; A case sensitive string
    base64
    ; Use base64 defined in [RFC4648] Section 5
    uid
    = uid-root 1*("." uid-part)
    uid-root
    = "0" / "1" / "2"
    uid-part
    = "0" / pos-int

### 5.1.2 URI Templates

The URI Template [RFC6570] syntax has been extended to allow case sensitive variable names. This has been done by modifying the varchar production (see [RFC6570] Section 2.3) as follows:

    varchar = %x20-21 / %x23-7E / pct-encoded

### 5.1.3 List Rule('#')

The ABNF has been extended with the List Rule, which is used to define comma-separated lists. It does not allow empty lists, empty list elements, or the legacy list rules defined in [RFC7230] Section 7.

    1#element = element *(OWS "," OWS element)

    #element = 1#element

    <n>#<m>element = element <n-1>*<m-1> (OWS "," OWS element)

Where

    n >= 1 and m > n

## 5.2 Web Service Section Structure

This Part of the Standard is organized so that new Services may be appended as new numbered sections at the end of the document.

## 5.3 Request and Response Header Field Tables

Request header field requirements are described using tables of the following form:

Table 5.2-1. Request Header Fields

Name | Value | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
... |  |  |  |
... |  |  |  |

The Name column contains the name of the HTTP header field as defined in [RFC7230, RFC7231].

The Value column defines either the value type or the specific value contained in the header field.

The Usage User Agent column defines requirements for the user agent to supply the header field in the request.

The Usage Origin Server column defines requirements for the origin server to support the header field.

The content of the Usage columns is either:

M

  Mandatory

C

  Conditional

O

  Optional

The Description column of conditional request header fields specifies the condition for the presence of the header field.

- "Shall be present if <condition>" means that if the <condition> is true, then the header field shall be present; otherwise, it shall not be present.

- "May be present otherwise" is added to the description if the header field may be present, even if the condition is not true.

Response header field requirements are described using tables of the following form:

Table 5.2-2. Response Header Fields

Name | Value | Origin Server Usage | Description
--- | --- | --- | ---
... |  |  |
... |  |  |

For response header fields the Usage column defines requirements for the origin server to supply the header field.

# 6 Conformance

An implementation claiming conformance to this Part of the Standard shall function in accordance with all its mandatory sections.

DICOM Web Services are used to transmit Composite SOP Instances. All Composite SOP Instances transmitted shall conform to the requirements specified in other Parts of the Standard.

An implementation may conform to the DICOM Web Services by supporting the role of origin server or user agent, or both, for any of the Services defined in this Part of the Standard. The structure of Conformance Statements is specified in PS3.2.

An implementation shall describe in its Conformance Statement the Real-World Activity associated with its use of DICOM Web Services, including any proxy functionality between a Web Service and the equivalent DIMSE Service.

An implementation shall describe in its Conformance Statement the security mechanisms utilized by the implementation.

# 7 Overview of DICOM Web Services (Informative)

## 7.1 DICOM Web Service Types

This Part of the Standard defines DICOM Web Services. Each service allows a user agent to interact with an origin server to manage a set of DICOM Resources. Each DICOM Web Service operates on a set of resources and defines a set of Transactions that operate on those resources. All Transactions are defined in terms of HTTP request/response message pairs.

When used in this Part of the Standard, the term HTTP refers to the family of HTTP protocols including: HTTP/1.1, HTTPS/1.1, HTTP/2, and HTTPS/2, as defined by the relevant IETF RFCs, but does not include HTTP/1.0 or HTTPS/1.0. The HTTP standards are normative for all aspects of HTTP message format and transmission.

There are two general types of DICOM Web Services: URI and RESTful. This distinction is based on the type of web service protocol used to specify resources and transactions.

### 7.1.1 URI Web Service

The URI Web Service retrieves representations of its resources, those resources being Composite SOP Instances (Instance). The URI service defines two transactions that retrieve Instances in different media types. All URI transactions use the query component of the URI in the request message to specify the transaction.

The functionality of the URI Web Service Transactions is similar to, but more limited than, the Retrieve Transaction of the Studies Web Service.

### 7.1.2 RESTful Web Services and Resources

Each RESTful Web Service defines the set of resources, and the transactions that can be applied to those resources.

The defined RESTful Web Services are:

Studies Web Service

  Enables a user agent to manage Studies stored on an origin server.

Worklist Web Service

  Enables a user agent to manage the Worklist containing Workitems stored on an origin server.

Non-Patient Instance Web Service

  Enables a user agent to manage Non-Patient Instances, e.g., Color Palettes, stored on an origin server.

## 7.2 Resources, Representations, and Target URIs

In RESTful Web Services, a resource is an abstract object with a type, associated data, relationships to other resources,and a set of methods that operate on it. Resources are grouped into collections. Collections are themselves resources as well. Each collection is unordered and contains only one type of resource. Collections can exist globally, at the top level of an API, but can also be contained inside a resource. In the latter case, we refer to these collections as sub-collections. Sub-collections usually express some kind of "contained in" relationship.

### 7.2.1 DICOM Restful Resources

The DICOM Resources defined in this Part of the Standard are typically either a DICOM Web Services or DICOM Information Objects. Examples include Studies, Series, Instances, Worklists, and Workitems.

DICOM Resources are grouped into collections and hierarchies. The following resources are examples of collections:

Resource Path | Contents
--- | ---
/studies | A collection of Studies.
/series | A collection of Series.
/instance | A collection of Instance.
/frames | A sequence of Frames.

The following resources are examples of hierarchies:

/studies/{study}/series | Contains a collection of Series.
/studies/{study}/series/{series}/instances | Contains a collection of Instances.
/studies/{study}/series/{series}/instances/{instance}/frames | Contains a sequence of frames.

A DICOM Web Service origin server manages a collection of resources. This might not be done directly; for example, an origin server could act as a proxy, converting RESTful requests into DIMSE requests, and DIMSE responses into RESTful responses.

Resources are typically created and/or accessed by user agents.

### 7.2.2 Representations

A resource is an abstract concept that is made concrete by a representation, which is a data object encoded in an octet-stream. For example, a DICOM Study (abstract) might be represented by a sequence of octets encoded in DICOM Media Type. See Section 8.7.3.

A media type describes the format or encoding of a representation. Examples of media types are application/dicom, application/dicom+json, image/jpeg, and text/html.

### 7.2.3 Target URIs

Resources are identified by URIs. Each service defines the resources that it manages and the format of the URIs used to reference those resources. The format of URIs is defined using URI Templates. See [RFC6570].

# 8 Common Aspects of DICOM Web Services

This section describes details and requirements that are common to all Web Services defined in this Part of the Standard.

A user agent or origin server that implements a Service in this Part of the Standard shall conform to Chapter 8 unless stated otherwise in the specification of that Service and its Transactions.

## 8.1 Transactions

Each transaction is composed of a request message and a response message, sometimes referred to as a request/response pair. When used in this Part of the Standard the term "request" means "request message", and "response" means "response message", unless clearly stated otherwise. Figure 8.1-1 is an interaction diagram that shows the message flow of a transaction. When it receives the request, the origin server processes it and returns a response.

The request includes a method, the URI of the Target Resource, and header fields. It might also include Query Parameters and a payload.

The response includes a status code, a reason phrase, header fields, and might also include a payload.

Figure 8.1-1. Interaction Diagram for Transactions

### 8.1.1 Request Message Syntax

This Part of the Standard uses the ABNF defined in Section 5.1 to define the syntax of transactions.

All Web Services API request messages have the following syntax:

    method SP target-uri SP version CRLF

    *(header-field CRLF)

    CRLF

    [payload]

Where

    method = "CONNECT" / "DELETE" / "GET" / "HEAD" / "OPTIONS" / "POST" / "PUT"
| Each transaction defines the method it uses.
    SP= %x20
| The US-ASCII Space character
    target-uri = "/" {/resource} {?parameters*}
| Each transaction defines a URI Template for the Target Resource. The template specifies the format of URIs that reference the Target Resource of a request. See Section 8.1.1.2.
    version = ("HTTP" / "HTTPS") "/" ("1.1" / "2")
| The version of the HTTP protocol; one of "HTTP/1.1", "HTTP/2", "HTTPS/1.1", or "HTTPS/2".
    CRLF = %x0D.0A
| A US-ASCII carriage return (%x0D) followed by a linefeed (%x0A).
    *(header-field CRLF)
| Zero or more header fields each followed by a CRLF delimiter.
    [payload] = *OCTET / multipart-payload
| An optional payload containing zero or more 8-bit OCTETs.

### Note

The method, SP, version, CRLF, Accept, header-field, and payload are all HTTP productions from [RFC7230], and [RFC7231]. The definitions are reproduced here for convenience.

#### 8.1.1.1 Method

The request method is one of the HTTP methods, such as CONNECT, DELETE, GET, HEAD, OPTIONS, POST, PUT. See [RFC7230] Section 4.

#### 8.1.1.2 Target Resource

The Target Resource of a request is specified by the Target URI contained in the request message. See Section 8.2.

#### 8.1.1.3 Query Parameters

Query parameters are contained in the query component (see [RFC3986]) of the URI. The user agent may use Query Parameters to supply parameters to the request. See Section 8.3.

#### 8.1.1.4 Request Header Fields

Request header fields are used to specify metadata for the request. Most requests have one or more Content Negotiation (see Section 8.4.1) header fields. If a request has a payload, the request will have the corresponding Content Representation (see Section 8.4.2) and Payload (see Section 8.4.3) header fields.

#### 8.1.1.5 Request Payload

The payload of the request is an octet-stream containing the content of the message. See Section 8.6. The presence of a payload in a request is signaled by a Content-Length or Content-Encoding header field.

### 8.1.2 Response Message Syntax

The syntax of a response message is:

    versionSP status-codeSP reason-phrase CRLF

    *(header-field CRLF)

    CRLF

    [payload]

Where

    status-code = 3DIGIT
| A three-digit code specifying the status of the response.
    reason-phrase = *(HTAB / SP / VCHAR)
| A human readable phrase that corresponds to the status. An implementation may define its own reason phrases. The reason-phrase syntax is slightly modified from that in [RFC7230]; this Part of the Standard does not allow obsolete text (obs-text) in the reason-phrase.

### Note

The status-code production is from [RFC7230].

The origin server shall always return a response message.

#### 8.1.2.1 Status Codes

The response message shall always include a valid 3-digit status code. Section 8.5 defines the status codes used by transactions. IANA maintains a registry of HTTP Status codes. See [IANA HTTP Status Code Registry].

#### 8.1.2.2 Response Header Fields

Response header fields are used to specify metadata for the response. The response will have the Content Representation (see Section 8.4.2) and Payload (see Section 8.4.3) header fields that correspond to the contents of the payload.

#### 8.1.2.3 Response Payload

The payload of the response is an octet-stream containing one or more representations. See Section 8.6.

A transaction typically defines two types of payloads for a response message: a success payload, and a failure payload.

A failure response payload should contain a Status Report describing any failures, warnings, or other useful information.

## 8.2 Target Resources

Transaction specifications define what resource types are valid Target Resources for the transaction and define the format of the URI for the Target Resource (and Query Parameters) using URI Templates. The URI of a Target Resource is referred to as the Target URI. Transaction specifications also define what resource types are valid resources for the response.

A Target URI is composed of three components: The Base URI, the Target Resource Path, and Query Parameters (which are often optional).

No whitespace is permitted in URIs. Whitespace around line breaks and the line breaks themselves should be stripped before parsing the URI. See [RFC3986] Appendix C.

The most general template for a Target URI is:

    target-uri = "/" {/resource} {?optional*}

or if any of the Query Parameters are required

    target-uri = "/" {/resource} ?{required*}{&optional*}

Where

    "/"
| The slash character ('/') is used to designate the Base URI.
    {/resource}
| A URI template for the Target Resource Path, a relative path component that references the Target Resource. The '/' in the template indicates that reserved characters, such as '/', can be used in the template expansion. See [RFC6570]. "/{/resource}" indicates the absolute URI to the Target Resource on the origin server.
    {required*}
| A URI Template for one or more required query parameters. See Section 8.1.1 for an example.
    {&optional*)
| A URI Template for zero or more optional query parameters. See Section 8.3.1 for an example.

The Base URI of a Service is an absolute URI that specifies the location of the origin server implementing the Service. Each Target URI defined by this Part of the Standard starts with a "/", which is a shorthand that designates the Base URI of the Service. The Base URI may support more than one Service.

The Service Root Path is the Base URI without the Scheme and Authority components.

The Target Resource Path is a relative URI that specifies the path to the resource from the Base URI of the Service. It is specified by a URI Template that uses Path Expansion {/var} as defined in [RFC6570].

For example, given the URI:

    http://dicom.nema.org/service/studies/2.25.123456789/series/2.25.987654321

The Base URI is:

    http://dicom.nema.org/service

The Service Root Path is:

    /service

The Target Resource Path is:

    /studies/2.25.123456789/series/2.25.987654321

The URI Template for this resource is:

    /studies/{study}/series/{series}

Where

    {study}
| is the Study Instance UID of a Study
    {series}
| is the Series Instance UID of a Series

## 8.3 Query Parameters

Query Parameters are specified in the query component of the URI (see [RFC3986] Section 3.4.

The query component of a request URI may only be used to specify one or more Query Parameters. These parameters are referred to as Query Parameters to distinguish them from header field parameters or other types of parameters that may be contained in the payload.

The Query Parameters are specified using a URI Template that uses Form {?var} and Query Continuation Style {&var} Query Expansion as defined in [RFC6570].

If a Target URI includes a "query component" (see [RFC3986] Section 3.4), it shall contain Query Parameters that conform to the syntax defined here.

The Services and Transactions defined elsewhere in this Part of the Standard may further refine the qp-name and qp-value rules defined below.

[RFC3986] does not permit an empty query component, i.e., if the "?" appears in the Target URI, then there shall be at least one Query Parameter in the URI.

The origin server may define and support additional Query Parameters, or additional Query Parameter values for an existing Query Parameter. If an origin server defines new or extends existing Query Parameters, they shall be documented in the Conformance Statement and, if the service supports it, the Retrieve Capabilities response.

The origin server shall ignore any unsupported Query Parameters. The origin server shall process the request as if the unsupported parameters were not present and may return a response containing appropriate warning and/or error messages.

If a supported Query Parameter has an invalid value, the origin server shall return a 400 (Bad Request) error response and may include a payload containing an appropriate Status Report.

### 8.3.1 Query Parameter Syntax

Query parameters have the following syntax:

    query-parameters = "?" parameter [*("&" parameter) ]

Each parameter after the first, is separated from the following parameter by the "&" character. Each parameter has the following syntax:

    parameter = qp-name
              / qp-name "=" 1#qp-value
              / qp-name "=" 1#attribute
              / attribute
              / attribute "=" 1#qp-value

The qp-name is case sensitive, and starts with an alphabetic or underscore character, followed by zero or more alphanumeric or underscore "_" characters:

    name =%s DQ 1*(ALPHA / "_") *(ALPHA / DIGIT / "_") DQ

A qp-name by itself (with no values) is a legal Query Parameter. A parameter <name> may also be followed by a comma-separated list of one or more qp-values, or one or more Attributes.

The qp-values are case-sensitive. A qp-value is composed of qp-chars, where qp-char is the set of legal query component characters as defined by [RFC3986], minus the equal ("="), ampersand ("&"), and comma (",") characters.

    qp-value   = %s DQ 1*qp-char DQ
    qp-char    = unreserved / pct-encoded / qp-special
    qp-special = "!" / "$" / "'" / "(" / ")" / "*" / "+" / ";" /":" / "@" / "/" / "?"

The only visible US-ASCII characters disallowed in the query component by [RFC3986] are "#", "[", "]". This Part of the Standard further disallows "&", "=", and ",". However, the characters ("#", "[", "]" "&", "=", and ",".) may be included in qp-values if they are percent encoded.

Each Attribute is either a simple-attribute or a sequence-attribute:

    attribute = simple-attribute / sequence-attribute

A simple-attribute is a single Data Element Tag or Keyword (see Table 6-1 “Registry of DICOM Data Elements” in PS3.6) that does not have a VR of SQ:

    simple-attribute = keyword / tag
    keyword          = %s DQ 1*ALPHA *(ALPHA / DIGIT) DQ
    tag              = 8HEXDIG

DICOM keywords are case sensitive; they shall start with an alphabetic character followed by zero or more alphanumeric characters. See PS3.6.

A sequence-attribute is two or more attributes separated by the dot character ("."), all but the last attribute shall have a VR of SQ, and the last attribute shall not have a VR of SQ.

sequence-attribute = (keyword / tag) *("." attribute)

The following are examples of valid values for attribute:

    0020000D

    StudyInstanceUID

    00101002.00100020

    OtherPatientIDsSequence.PatientID

    00101002.00100024.00400032

    OtherPatientIDsSequence.IssuerOfPatientIDQualifiersSequence.UniversalEntityID

Some Query Parameters have a qp-name, which is an attribute, and a value that is a comma-separated list of one or more qp-values. The qp-values of an attribute parameter shall satisfy its Value Representation and Value Multiplicity, as defined in PS3.5 and PS3.6, of the corresponding attribute.

Unlike the Value Representations defined in PS3.5, Query Parameters:

- shall not be padded to an even length

- shall not contain any NULL (%x00) characters

- shall encode UIDs as specified in PS3.5, except that they shall not be padded to an even length

#### 8.3.1.1 Query Parameter Syntax

The syntax and semantics of valid qp-names, qp-values and attributes are specified by the defining Service or Transaction; however, they shall conform to the rules in this Section.

Table 8.3.1-1 contains the collected syntax of Query Parameters. The Services and Transactions defined elsewhere in this Part of the Standard may further refine the qp-name, attribute, and qp-value rules.

All qp-names are case sensitive.

Table 8.3.1-1. ABNF for Query Parameter

Name | Rule
--- | ---
    query-parameters
    = "?" parameter *("&" parameter)
    parameter
    = qp-name; a name only
    / qp-name "=" 1#qp-value ; a name with one or more values
    / qp-name "=" 1#attribute; a name with one or more attributes
    / attribute; an attribute only
    / attribute "=" 1#qp-value ; an attribute with one or more values
    qp-name
    = %s (ALPHA / "_") *(ALPHA / DIGIT / "_")
    qp-value
    =int / uint / pos-int / decimal / float /string / base64 / uid
    / %s 1*qp-char/ %s DQ 1*qp-special DQ; See Section 5.1.1
    qp-char
    = unreserved / pct-encoded
    qp-special
    = "!" / "$" / "'" / "(" / ") " / "*" / "+" / ";"/":" / "@" / "/" / "?"
    simple-attribute
    = keyword / tag
    sequence-attribute
    = keyword *( "." attribute) / tag *( "." attribute )
    keyword
    = %suppercase *( ALPHA / DIGIT )
    uppercase
    =%x41-5A
    tag
    = 8HEXDIG

### Note

The syntax of qp-values is defined in Section 5.1.1.

The qp-char (Query Parameter characters) rule defined above is the query rule of [RFC3986], which defines the legal characters for the query component, minus the equal sign ("="), comma (","), and ampersand ("&"). So, the qp-char rule is the VCHAR rule minus "#", "[", "]", "=", "&", and ",".

All DICOM keywords are case sensitive. See PS3.6.

### 8.3.2 Query Parameter Usage

An implementation's support for Query Parameters is either Mandatory or Optional. Each Query Parameter section contains a table specifying Query Parameter keys, values, user agent and origin server usage requirements. Table 8.3.2-1 specifies the usage symbols, types, and definitions.

Table 8.3.2-1. Query Parameter Usage

Symbol | Type
--- | ---
M | Mandatory
C | Conditional
O | Optional

Table 8.3.2-2 shows an example Query Parameter table.

Table 8.3.2-2. Example Query Parameter Table

Name | Values | Usage | Section
User Agent | Origin Server
requestType | "WADO" | M | M | Section 9.1.2.1.1
studyUID | uid | M | M | Section 9.1.2.1.3
seriesUID | uid | M | M | Section 9.1.2.1.3
objectUID | uid | M | M | Section 9.1.2.1.4

The usage columns specify the Query Parameters that the user agent must supply, and the origin server must support.

### 8.3.3 Content Negotiation Query Parameters

The parameters defined in this section are primarily designed for use in hyperlinks, i.e., URIs embedded in documents, where the Content Negotiation header fields (see Section 8.3.3) are not accessible.

#### 8.3.3.1 Accept Query Parameter

The Accept Query Parameter has the following syntax:

    accept      = accept-name "=" 1#(media-type [weight])
    accept-name = %s"accept"

The Accept Query Parameter has the same syntax as the Accept header field (see Section 8.4.3), except that it shall not have wildcards (<type>/* or */*). See Section 8.7.

### Note

1. The normal name of this parameter is "accept"; however, the URI Service uses an accept-name of "contentType". See Section 9.1.2.2.1.

2. The "%s" that prefixes the accept-name specifies that it is a case sensitive token. See [RFC7405].

The parameter value is a comma-separated list of one or more media-types.

The Accept Query Parameter should not be used when the user agent can specify the values by using the Accept header field.

All media types present in an Accept Query Parameter shall be compatible with a media range in the Accept header field, either explicitly or implicitly through wildcards.

### Note

For example, the presence of image/jpeg in the Accept Query Parameter will require the Accept header field to include one or more of the following values: image/jpeg, image/*, or */*.

If none of the Acceptable Media Types (see Section 8.7.5) are supported by the origin server, the origin server response shall be in the default media type for the Resource Category of the Target Resource. If there is no default media type defined for the Target Resource, the origin server response shall be 406 (Not Acceptable) and may include a payload containing an appropriate Status Report.

If a DICOM Media Type is present, non-DICOM Media Types shall not be present. If both DICOM and non-DICOM Media Types are present, the response shall be 400 (Bad Request), and may include a payload containing an appropriate Status Report.

#### 8.3.3.2 Character Set Query Parameter

The Character Set Query Parameter has the following syntax:

    character-set = "charset" "=" 1#(charset [weight])

The Character Set Query Parameter value is a comma-separated list of one or more character set identifiers. It is like the Accept-Charset header field, except that it shall not have wildcards. See Section 8.8.

### Note

Character set identifiers present in the character set Query Parameter typically have a corresponding character set identifier in the Accept-Charset header field, either explicitly or implicitly through wildcards.

If this parameter has a value that is not a valid or supported character set, the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate Status Report. See Section 8.6.3.

### 8.3.4 Search Query Parameters

Table 8.3.4-1 contains the syntax for the names and values of search parameters, along with a reference to the section where their meaning is defined. Search transactions shall support these parameters. The ABNF for the various search parameters is:

Table 8.3.4-1. Query Parameter Syntax

Term | Value | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
    search
    = match / fuzzymatching / includefield
    / limit / offset
    match
    ; See attribute matching rules below
| O | M | Section 8.3.4.1
    fuzzymatching
    = "fuzzymatching" "=" true / false
| O | M | Section 8.3.4.2
    includefield
    = "includefield" "=" 1#attribute / "all"
| O | M | Section 8.3.4.3
    limit
    = "limit" "=" uint ; Maximum number of results
| O | M | Section 8.3.4.4
    offset
    = "offset" "=" uint ; Number of skipped results
| O | M | Section 8.3.4.4

The following sections describe these parameters in detail.

#### 8.3.4.1 Attribute Matching

The syntax of the match Query Parameter shall be:

    match          = normal-match / uid-list-match
    normal-match   = 1*("&" attribute "=" value)
    uid-list-match = 1*("&" attribute "=" 1#value)
    attribute      = (attribute-id) *("." attribute-id)
    attribute-id   = tag *("." tag) / keyword *("." keyword)
    tag            = 8HEXDIG

    keyword= ;A keyword from Table 6-1 “Registry of DICOM Data Elements” in PS3.6.

One or more DICOM Attribute/Values pairs specify the matching criteria for the search.

Each search transaction defines which Attributes are required or permitted.

### Note

DICOM Attributes should not be confused with XML attributes. The Tags and Keywords for DICOM Attributes are defined in Table 6-1 “Registry of DICOM Data Elements” in PS3.6.

DICOM Attribute/Values pairs shall satisfy the following requirements:

1. Each attribute-id shall be a Data Element Tag or Keyword.

2. Each attribute in the Query Parameter shall be not be repeated.

3. Each attribute in the Query Parameter shall have a single value, unless the associated DICOM Attribute allows UID List matching (see Section C.2.2.2.2 in PS3.4 ), in which case the value is a comma-separated list of UIDs.

4. The acceptable values are determined by the types of matching allowed by C-FIND for its associated attribute. See Section C.2.2.2 in PS3.4 . All characters in values that are not qp-chars shall be percent-encoded. All non-ASCII characters shall be percent encoded. See [RFC3986] for details.

The following US-ASCII characters"#", "[", "]", "&", "=", and "," shall be percent encoded in any Query Parameter.

The match Query Parameter corresponds to DIMSE Matching Keys. See Section K.2.2.1.1 in PS3.4 .

##### 8.3.4.1.1 Matching Rules

The matching semantics for each attribute are determined by the types of matching allowed by C-FIND. See Section C.2.2.2 “Attribute Matching” in PS3.4.

Matching results shall be generated according to the Hierarchical Search Method described in Section C.4.1.3.1.1 “Hierarchical Search Method” in PS3.4.

Combined date-time matching shall be performed as specified in Section C.2.2.2.5 “Range Matching” in PS3.4.

### Note

If an origin server is acting as a proxy for a C-FIND SCP that does not support combined date-time matching, it shall perform a C-FIND request using only the date and filter any results that are outside the time range before returning a response.

If the Timezone Offset From UTC (0008,0201) Attribute is specified in the request, dates and times in the request are to be interpreted in the specified time zone. See Section C.4.1.1 in PS3.4 .

#### 8.3.4.2 Fuzzy Matching of Person Names

A single parameter specifies whether Fuzzy Matching of Person Names is to be performed.

This parameter is optional for the user agent.

This parameter is optional for the origin server.

If this parameter is not present its value is "false".

    fuzzymatching = "fuzzymatching" "=" ("true" / "false")

If the value is "false", then the search shall be performed without Fuzzy Matching.

If the value is "true" and the origin server supports Fuzzy Matching, then the search shall be performed with Fuzzy Matching of Person Name Attributes as specified in Section C.2.2.2.1.1 in PS3.4 and shall be documented in the Conformance Statement and, if the service supports it, the Retrieve Capabilities response.

If the value is "true" and the origin server does not support Fuzzy Matching, then:

- The search shall be performed without Fuzzy Matching.

- The response shall include the following HTTP Warning header (see [RFC7234] Section 5.5) :

      Warning: 299 <service>: The fuzzymatching parameter is not supported. Only literal matching has been performed.

  where <service> is the base URI for the origin server. This may be a combination of scheme, authority, and path.

- The response may include a payload containing an appropriate Status Report.

#### 8.3.4.3 Attributes Included in the Response

A parameter specifies the Attributes that should be included in the response. The value is either a comma-separated list of attributes, or the single keyword "all", which means that all available attributes of the object should be included in the response.

    includefield = *("includefield" "=" (1#attribute / "all") )

The request may contain one or more include parameters; however, if a parameter with the value of "all" is present, then other includefield parameters shall not be present. If an attribute is a value of an includefield parameter, it is equivalent to C-FIND Universal matching for that attribute. See Section C.2.2.2.3 in PS3.4 .

The includefield Query Parameter corresponds to DIMSE Return Keys. See Section K.2.2.1.2 in PS3.4 .

#### 8.3.4.4 Response Pagination

The following two parameters can be used to paginate a search response that might contain more matches than can readily be handled.

    offset = "offset" "=" uint

A single parameter specifies the number of matches the origin server shall skip before the first returned match. The "offset" parameter value is an unsigned integer (uint). If this Query Parameter is not present, its value defaults to 0.

    limit = "limit" "=" uint

A single parameter specifies the maximum number of matches the origin server shall return in a single response. The "limit" parameter value is an unsigned integer. If this parameter is not present, its value is determined by the origin server.

##### 8.3.4.4.1 Paging Behavior

The search requests shall be idempotent, that is, two separate search requests with the same Target Resource, Query Parameters, and header fields shall return the same ordered list of matches, if the set of matches on the origin server has not changed.

Given the following definitions:

    offset
| the value of the "offset" query parameter.
    limit
| the value of the "limit" query parameter.
    maxResults
| the maximum number of results the origin server allows in a single response.
    matches
| the number of matches resulting from the search.
    results
| the number of results returned in the response. It is equal to the minimum of: The maximum of zero and the value of matches - offset The value of maxResults The value of limit
    remaining
| the number of matches that were not yet returned.

The results returned in the response are determined as follows:

- If (results <= 0) then there are no matches, and a 204 (No Content) response shall be returned with an empty payload.

- Otherwise, a 200 (OK) response shall be returned with a payload containing the results.

- If (remaining > 0) the response shall include a Warning header field (see [RFC7234] Section 5.5) containing the following:

      Warning: 299 <service>: There are <remaining> additional results that can be requested

The response may include a payload containing an appropriate Status Report.

If the set of matching results has changed due to changes in the origin server contents, then the ordered list of results may be different for subsequent transactions with identical requests, and the results of using the "offset" and "limit" parameters may be inconsistent.

### 8.3.5 Rendering Query Parameters

This section defines the Query Parameter syntax and behavior for Retrieve requests for Rendered Media Types.

All Retrieve transactions for Rendered Media Types shall support these parameters.

#### 8.3.5.1 Query Parameters For Rendered Resources

The Query Parameters defined in this section specify various rendering transformations to be applied to the DICOM images, video, and text contained in the parent DICOM Resource.

The following rules pertain to all parameters defined in this section:

1. All parameters are optional for the user agent.

2. Not all parameters are required to be supported by the origin server.

3. These parameters only apply to resources that are images and video.

The set of transformations specified by the parameters in this section shall be applied to the images as if the parameters were a Presentation State, that is, in the order specified by the applicable image rendering pipeline specified in PS3.4.

Table 8.3.5-1 shows the Query Parameters that may be used when requesting a Rendered Representation.

Table 8.3.5-1. Retrieve Rendered Query Parameters

Key | Values | Target Resource Category | Section
--- | --- | --- | ---
    accept
    Rendered Media Type
| All Categories | Section 8.3.3.1
    annotation
    "patient" and/or "technique"
| Image (single or multi-frame) or Video | Section 8.3.5.1.1
    charset
    character set token
| All Categories | Section 8.3.3.2
    quality
    Integer
| Image (single or multi-frame) or Video | Section 8.3.5.1.2
    viewport
    vw, vh, [ sx, sy, sw, sh ]
| Non-Presentation States | Section 8.3.5.1.3
    viewport
    vw, vh,
| Presentation States | Section 8.3.5.1.3
    window
    center, width, shape
| Non-Presentation States | Section 8.3.5.1.4
    iccprofile
    "no", "yes", "srgb", "adobergb" or "rommrgb"
| Image (single or multi-frame) or Video | Section 8.3.5.1.5

##### 8.3.5.1.1 Image Annotation

This parameter specifies that the rendered images or video will have annotations. Its name is "annotation" and its value is a comma-separated list of one or more keywords. It has the following syntax:

    annotation = %s"annotation=" 1#( %s"patient" / %s"technique" )

Where

    "patient"
| Indicates that the rendered images shall be annotated with patient information (e.g., patient name, birth date, etc.).
    "technique"
| Indicates that the rendered images shall be annotated with information about the procedure that was performed (e.g., image number, study date, image position, etc.).

When this parameter is not present, no annotations shall be applied.

The image rendering pipelines specified in PS3.4 require that annotations be applied after all other parameters have been applied and the image or video has been rendered. The exact nature and presentation of the annotations is determined by the origin server and is "burned-in" to the rendered content.

The origin server may support additional keywords, which shall be documented in the Conformance Statement and, if the service supports it, the Retrieve Capabilities response.

If any of the parameter values are not keywords, or there are no parameter values, the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

The origin server shall ignore any unsupported parameter values. If unsupported values are present, the origin server shall include the following header field:

    Warning 299 <service>: The following annotation values are not supported: <values>

and may include a payload containing an appropriate warning message.

### Note

1. The exact nature and presentation of the annotation is determined by the origin server. The annotation is burned into the rendered image pixels.

2. A user agent wanting more control over annotations may retrieve an image, omitting the "annotation" parameter, and separately retrieve the metadata, and create customized annotations on the image.

3. A user agent wanting more control over annotations can retrieve an image, omitting the "annotation" parameter, separately retrieve the metadata, and create customized annotations on the image.

4. The Target Resource could already contain "burned-in" text that is beyond the control of this parameter.

##### 8.3.5.1.2 Image Quality

The "quality" parameter specifies the requested quality of the rendered images or video. It has the following syntax:

    quality = %s"quality=" integer

Where

    integer
| is an unsigned integer between 1 and 100 inclusive, with 100 being the best quality.

If the value of this parameter is missing or is not an integer between 1 and 100 inclusive, the response shall be a 400 (Bad Request) and may include a payload containing an appropriate error message.

The "quality" parameter is only supported for media types that allow lossy compression.

The meaning of this parameter is determined by the origin server and shall be documented in the Conformance Statement and, if the Service supports it, Retrieve Capabilities response.

### Note

1. Decompression and re-compression may degrade the image quality if the original image was already irreversibly compressed. If the image has been already lossy compressed using the same format as required (e.g., jpeg), it may be sent as it is without decompressing and re-compressing it.

2. The origin server could choose to disregard the quality parameter if the resultant image quality would be too low.

##### 8.3.5.1.3 Viewport Scaling

The "viewport" parameter specifies a rectangular region of the source image(s) or video to be cropped, and a rectangular region corresponding to the size of the user agent's viewport to which the cropped image or video should be scaled.

The syntax of this parameter for a Presentation State Instance or a Thumbnail is:

    %s"viewport=" vw "," vh

Otherwise it is:

    %s"viewport=" vw "," vh ["," [sx] "," [sy] "," [sw] "," [sh] ]

Where

    vw and vh
| are positive integers specifying the width and height, in pixels, of the rendered image or video. Both values are required.
    sx and sy
| are decimal numbers whose absolute values specify, in pixels, the top-left corner of the region of the source image(s) to be rendered. If either sx or sy is not specified, it defaults to 0. A value of 0,0 specifies the top-left corner of the source image(s).
    sw and sh
| are decimal numbers whose absolute values specify, in pixels, the width and height of the region of the source image(s) to be rendered. If sw is not specified, it defaults to the right edge of the source image. If sh is not specified, it defaults to the bottom edge of the source image. If sw is a negative value, the image is flipped horizontally. If sh is a negative value, the image is flipped vertically.

The origin server shall crop the source images or video to the region specified by sx, sy, sw, and sh. It shall then scale the source content, maintaining the aspect ratio of the cropped region, until either the rendered content width or height is the same as the viewport width or height, whichever avoids truncation. In other words, viewport scaling makes the image(s) as large as possible, within the viewport, without overflowing the viewport area and without distorting the image.

If any of the optional parameter values are not present, the default value shall be used. Individual values may be elided, but the commas between the values shall be present. For example:

    viewport=512,512,,,512,512

The missing sx and sy parameter values default to 0.

If trailing values are elided, then the trailing commas shall be omitted. For example:

    viewport=1024,1024

The missing sx, sy, sw, sh will have their default values, i.e., the image(s) shall not be cropped, i.e., the full image is rendered.

If the viewport parameter is not present, the rendered image(s) or video shall not be scaled, i.e., the rendered image(s) shall contain the same sized pixel matrix as the source DICOM image.

If any of the following are true:

- This parameter specifies viewport dimensions that are either ill-formed or not supported

- The Target Resource is a Presentation State or Thumbnail and anything other than vw and vh are specified

then the response shall be 400 (Bad Request) and may include a payload containing an appropriate Status Report.

### Note

The default values for sx and sy differ from the defaults in the Specified Displayed Area in Presentation States, which uses integer values with the top left corner being (1\1). See Section C.10.4 in PS3.3 .

##### 8.3.5.1.4 Windowing

The "window" parameter controls the windowing of the images or video as defined in Section C.8.11.3.1.5 in PS3.3 . It has the following syntax:

    %s"window=" center "," width "," function

Where

    center
| is a decimal number containing the window-center value
    width
| is a decimal numbercontaining the window-width value
    function
| is one of the following keywords: "linear", "linear-exact", or "sigmoid".

### Note

These correspond to the differently capitalized and punctuated values of VOI LUT Function (0028,1056). See Section C.11.2.1.2 in PS3.3 .

All three parameters shall be present with valid values.

If any of the parameter values are missing or ill-formed, the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

If the Target Resource is a Presentation State, this parameter shall not be used. If this parameter is present when the Target Resource is a Presentation state, the origin server shall return a 400 (Bad Request).

##### 8.3.5.1.5 ICC Profile

The "iccprofile" parameter specifies the color characteristics of, and inclusion of an ICC Profile in, the rendered images. It has the following syntax:

    %s"iccprofile=" 1#( %s"no" / %s"yes" / %s"srgb" / %s"adobergb" / %s"rommrgb" )

Where

"no" | indicates that no ICC profile shall be present in the rendered image in the response.
"yes" | indicates that an ICC profile shall be present in the rendered image in the response, describing its color characteristics, if the Media Type supports embedded ICC Profiles.
"srgb" | indicates that an sRGB ICC profile shall be present in the image, if the Media Type supports embedded ICC Profiles, and that the pixels of the rendered image in the response shall be transformed from their original color space and be encoded in the sRGB color space [IEC 61966-2.1].
"adobergb" | indicates that an Adobe RGB ICC profile shall be present in the image, if the Media Type supports embedded ICC Profiles, and that the pixels of the rendered image in the response shall be transformed from their original color space and be encoded in the Adobe RGB color space [Adobe RGB].
"rommrgb" | indicates that a ROMM RGB ICC profile shall be present in the image, if the Media Type supports embedded ICC Profiles, and that the pixels of the rendered image in the response shall be transformed from their original color space and encoded in the ROMM RGB color space [ISO 22028-2].

When this parameter is not present:

- an ICC profile may or may not be present in the image in the response;

- the color characteristics of the image in the response may or may not be consistent with any DICOM ICC Profile (0028,2000) Attribute in the metadata.

The ICC Profile in the image in the response shall be:

- the ICC profile of the color space specified explicitly by the parameter,

- otherwise, the ICC profile encoded in the source DICOM ICC Profile (0028,2000) Attribute, if any, appropriate to the selected frame,

- otherwise, the ICC profile, if any, embedded in the stored compressed representation of the selected frame,

- otherwise, at the discretion of the origin server, the ICC profile of a well-known color space listed in Section C.11.15.1.2 “Color Space” in PS3.3 that is appropriate to the type and source of the image.

If the Media Type does not support embedded ICC Profiles:

- a 400 Bad Request error shall be returned if the parameter value is other than "no"

### Note

1. This parameter allows ICC profile information to be present in the image in the response so that the user agent can make use of it for local color management (e.g., an ICC profile capable browser can apply the profile when displaying the rendered image in the response).

2. This parameter provides a limited mechanism for requesting that the origin server perform some color management. It provides the names of well-known color spaces for the rendered image in the response. It does not provide a mechanism to supply an arbitrary ICC profile, such as the calibration profile of a display, so it does not absolve the user agent from the need to handle its own color calibration and color management.

3. ICC profiles can theoretically be large relative to the compressed pixel data of a single frame, so the user agent may specify a parameter value of "no", retrieve the DICOM ICC Profile (0028,2000) Attribute value(s) that apply to multiple frames from the metadata, and combine these itself.

4. ICC profiles are embedded in rendered images of Media Type image/jpeg as one or more chunks in APP2 marker segments with an identifier of "ICC_PROFILE", as defined in Annex B of [ISO 15076-1].

5. ICC profiles are embedded in rendered images of Media Type image/jp2 either as JP2 Restricted or JPX Full profiles according to [ISO/IEC 15444-1] and [ISO/IEC 15444-2], respectively; rendered images in the response are not subject to the prohibition against inclusion of a JP2 box in JPEG 2000 compressed data streams in DICOM images.

6. ICC profiles are embedded in rendered images of Media Type image/png in an iCCP chunk, as defined in [ISO 15948].

#### 8.3.5.2 Query Parameters For Thumbnails

Table 8.3.5-2shows the Query Parameters that may be used when requesting a Thumbnail representation.

Table 8.3.5-2. Thumbnail Query Parameters

Key | Values | Target Resource Category | Section
--- | --- | --- | ---
    accept
    Rendered Media Type
| All Categories | Section 8.3.3.1
    charset
    character set token
| All Categories | Section 8.3.3.2
    viewport
    vw, vh
| All Categories | Section 8.3.5.1.3

The Viewport parameter only has width and height values. If no viewport parameter is provided the origin server will determine the size of the thumbnail.

## 8.4 Header Fields

The following sections specify important header fields, some of which have stronger requirements than those specified in the HTTP Standard.

### 8.4.1 Content Negotiation Header Fields

HTTP uses the Accept and Content-Type header fields for content negotiation and data typing. The media types in the Accept header field of a request define the media types that the user agent would find acceptable in the response. The media type in the Content-Type header field of a message, or payload part, describes the format of the representation contained in the message payload or payload part.

Content Negotiation header fields in requests allow the user agent to specify acceptable representations for the response. Table 8.4.1-1 lists the content negotiation header fields. The values in these fields apply to any content in the response, including representations of the Target Resource, representations of error or processing status, and potentially even the miscellaneous text strings that might appear within the HTTP protocol. See [RFC7231] Section 5.3.

Table 8.4.1-1. Content Negotiation Header Fields

Name | Value | Usage | Description
--- | --- | --- | ---
Accept | 1#media-range | M | All requests that expect to receive a response with a payload shall contain an Accept header field. See Section 8.4.1.1.
Accept-Charset | 1#charset | O | The Accept-Charset header field may be sent by a user agent to indicate what charsets are acceptable in response content. See [RFC7231] Section 5.3.3.
Accept-Encoding | 1#encoding | O | The Accept-Encoding header field may be used to indicate the content-codings (see [RFC7231] Section 3.1.2.1) acceptable in the response. See [RFC7231] Section 5.3.4.
Accept-Language | 1#language | O | The Accept-Language header field may be used by user agents to indicate the set of natural languages that are preferred in the response. See [RFC7231] Section 5.3.5.

#### 8.4.1.1 Accept

User agents use the Accept header field to specify Acceptable Media Types for the response payload. The Accept header field can be used to indicate that the response payload is specifically limited to a set of desired media types. It has the following syntax:

    Accept      = "Accept:" #( media-range [accept-params] )
    media-range = ("*/*"
                  / (type "/" "*")
                  / (type "/" subtype)
                  ) *(OWS ";" OWS accept-params)
    accept-params = weight *(accept-ext)

Most requests have an Accept header field that contains a comma-separated list of one or more media ranges. A media-range extends media-type with wildcards (*/* or type/*) and parameters that are not defined for media-types. See [RFC7231] Section 5.3.2 for details.

For example, if the user agent is willing to accept any media type in the response it should include */* as a value of the Accept header field.

Many of the content negotiation header fields use a weight parameter, named "q" (case-insensitive), to assign a relative "weight" to the preference for that associated kind of content.

The media types in the Accept header can be given a priority ordering by using weights.

    weight = OWS ";" OWS "q=" qvalue
    qvalue = ("0" ["." 0*3DIGIT])
           / ("1" ["." 0*3("0")])

This weight is often referred to as "quality value" or "qvalue". See [RFC7231] Section 5.3.1.

All requests that might have a response containing a payload shall provide an Accept header field.

See Section 8.7.5 for Acceptable Media Types.

##### 8.4.1.1.1 Charset Media Type Parameter

Many media types, especially text/* types, define a "charset" parameter that specifies the character set for the representation. See [RFC7231] Section 3.1.1.2.

DICOM Media Types define a "charset" parameter. See Section 8.7.3.5.3.

For example,

    application/dicom; charset=ISO-8859-1

See Section 8.8.1 for Acceptable Character Sets.

### 8.4.2 Content Representation Header Fields

The media type in the Content-Type header field of a message, or payload part, describes the format of the representation contained in the payload or part.

When a message has a payload, the Content Representation Header Fields provide metadata describing how to interpret the representation(s) contained in the payload. Table 8.4.2-1 describes the Content Representation Header Fields, and the usage requirements (Mandatory, Conditional, or Optional) for when they shall be present.

Table 8.4.2-1. Content Representation Header Fields

Name | Value | Usage | Requirement
--- | --- | --- | ---
Content-Type | media-type | C | Specifies the media type of the representation contained in the payload. If a message has a payload, it shall have a Content-Type header field specifying the media type of the payload. See [RFC7231] Section 3.1.1.5.
Content-Encoding | encoding | C | Specifies any content encodings applied to the representation (beyond those inherent in the media type), and thus what decoding to apply to obtain a representation in the media type specified by the Content-Type. See [RFC7230] Section 3.1.2.2. Content-Encoding allows compression, encryption, and/or authentication of representations. Shall be present if a content encoding has been applied to the representation in the payload.
Content-Language | language | O | Specifies the natural language(s) of the intended audience used in representation. See [RFC7231] Section 3.1.3.2.
Content-Location | url | C | Contains a URL that references the specific resource corresponding to the representation in the payload. Shall be present if the payload contains a representation of a resource.

### 8.4.3 Payload Header Fields

The Payload Header Fields contain metadata describing the payload, not the representation it contains. Table 8.4.3-1 describes the payload header fields, and the usage requirements (Mandatory, Conditional, or Optional) for when they shall be present.

Table 8.4.3-1. Payload Header Fields

Name | Value | Usage | Description
--- | --- | --- | ---
Content-Length | uint | C | Specifies the decimal number of octets in the payload. If the response message has a payload and does not have a Content-Encoding header field, it shall have a Content-Length header field specifying the length in octets (bytes) of the payload. Shall not be present if the message has a Content-Encoding header field. Shall be present otherwise, even is the size of the payload is zero.
Content-Range | range | C | Specifies the range of a partial representation contained in a payload. See [RFC7233] Section 4.2. The Content-Range header field is sent in a single part 206 (Partial Content) response to indicate the partial range of the selected representation enclosed as the message payload. It is sent in each part of a multipart 206 response to indicate the range enclosed within each body part. It is sent in 416 (Range Not Satisfiable) responses to provide information about the selected representation.
Transfer-Encoding | encoding | C | See [RFC7230] Section 3.3.1. Shall be present if transfer-encodings have been applied to the payload.

## 8.5 Status Codes

Each response message contains a status-code.

The most common HTTP status codes used are listed in Table 8.5-1 Most of these codes are described in detail in [RFC7231]. IANA maintains the HTTP Status Code Registry [IANA HTTP Status Code Registry], which contains a complete list of registered status codes.

Table 8.5-1. Status Code Meaning

Status | Code | Description
--- | --- | ---
Success | The 2xx (Successful) class of status code indicates that the client's request was successfully received, understood, and accepted.
200 (Success) | All Target Resource representations are contained in the payload. See [RFC7231] Section 6.3.1.
201 (Created) | The request has been fulfilled and has resulted in one or more new resources being created. See [RFC7231] Section 6.3.2.
202 (Accepted) | The request has been accepted for processing, but the processing has not been completed. The payload of this response should contain a Status Report. [RFC7231] Section 6.3.3. The user agent may be able to inspect relevant resources to determine the status at some later time.
203 (Non-Authoritative Information) | The request was successful, but the enclosed payload has been modified from that of the origin server's 200 (OK) response by a transforming proxy. See [RFC7230] Section 5.7.2 and [RFC7230] [RFC7231] Section 6.3.4.
204 (No-Content) | The server has successfully fulfilled the request and there is no additional content to send in the response payload body. This should be the response when content is successfully uploaded, and the response has no payload. For example, this status code is used in the response to a Conditional Retrieve request), when the Target Resource has not been modified. See [RFC7231] Section 6.3.5.
205 (Reset Content) | The server has fulfilled the request and desires that the user agent reset the "document view", which caused the request to be sent, to its original state as received from the origin server.
206 (Partial Content) | The 206 (Partial Content) status code indicates that the server is successfully fulfilling a range request for the Target Resource by transferring one or more parts of the selected representation that correspond to the satisfiable ranges found in the request's Range header field. This status code shall only be used with Range Requests. See [RFC7233]. ### Note This status code was previously (erroneously) used to indicate that only some of a payload was stored.
Redirection | The 3xx (Redirection) class of status code indicates that further action needs to be taken by the user agent to fulfill the request.
301 (Moved Permanently) | The origin server has assigned the Target Resource to a new permanent URI, indicated in a Location header field. This status is typically needed when the resource has been moved from one service to another, for example during a migration.
303 (See Other) | The origin the server is redirecting the user agent to a different resource, as indicated by a URI in the Location header field, which will provide a response to the original request.
304 (Not Modified) | The origin server has received a conditional GET or HEAD request that would have resulted in a 200 (OK) response if it were not for the fact that the condition evaluated to false.
Client Error | The 4xx (Client Error) class of status code indicates that the user agent has erred. For all these error codes,the origin server should return a payload containing an explanation of the error situation, and whether it is a temporary or permanent condition, except when responding to a HEAD request.
400 (Bad Request) | The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request â€¦).
401 (Unauthorized) | The request has not been fulfilled because it lacks valid authentication credentials for the service or Target Resource. The server generating a 401 response shall send a WWW-Authenticate header field ([RFC7235] Section 4.1) containing at least one challenge applicable to the server or Target Resource.
403 (Forbidden) | The origin server understood the request, but refused to authorize it (e.g., an authorized user with insufficient privileges). If authentication credentials were provided in the request, the server considers them insufficient to grant access. The origin server may respond with a 404 (Not Found) if not permitted to use this status code.
404 (Not Found) | The origin server did not find a representation for the Target Resource or is not willing to disclose that one exists. This might be a temporary condition. If the origin server knows that the resource has been deleted, the 410 (Gone) status code shall be returned rather than 404.
405 (Method Not Allowed) | The method in the request is known by the origin server but not supported by the target service or resource. The origin server shall include an Allow header field in a 405 response containing a list of the target service or resource's currently supported methods.
406 (Not Acceptable) | The Target Resource does not have a representation that would be acceptable to the user agent, per the content negotiation header fields in the request, and the server is unwilling to supply a default representation. The origin server should return a payload that lists the available media types and corresponding resource identifiers.
409 (Conflict) | The request could not be completed due to a conflict with the current state of the Target Resource. This code is used in situations where the user agent might be able to resolve the conflict and resubmit the request. The origin server should return a payload containing enough information for the user agent to recognize the source of the conflict. In the DICOM context, this code might indicate that the origin server was unable to store any Instances due to a conflict in the request (e.g., unsupported SOP Class or Instance mismatch).
410 (Gone) | Access to the Target Resource is no longer available at the origin server and this condition is likely to be permanent. If the origin server does not know, or has no facility to determine, whether the condition is permanent, the 404 (Not Found) status code should be used instead.
411 (Length Required) | The origin server refuses to accept the request because the Content-Length header field was not specified.
413 (Payload Too Large) | The server is refusing to process the request because the request payload is larger than the server is willing or able to process.
414 (URI Too Long) | The server is refusing to service the request because the request-target ([RFC7230] Section 5.3) is longer than the server is willing to interpret.
415 (Unsupported Media Type) | The origin server does not support the Content-Type in the request payload. This error typically occurs when the user agent is trying to create or update a resource. The origin server should return a payload that lists the available media types and corresponding resource identifiers. ### Note This is different from 406 (Not Acceptable).
Server Error | The 5xx (Server Error) class of status code indicates that the server is aware that it has erred or is incapable of performing the requested method. For all these error codes, the server should send an explanation of the error situation, and whether it is a temporary or permanent condition, except when responding to a HEAD request.
500 (Internal Server Error) | The server encountered an unexpected condition that prevented it from fulfilling the request.
501 (Not Implemented) | The server does not support the functionality required to fulfill the request. In the DICOM context, this status code shall be used for SOP Class Not Supported errors.
503 (Service Unavailable) | The origin server is currently unable to handle the request due to a temporary overload or scheduled maintenance, which will likely be alleviated after some delay.
505 (HTTP Version Not Supported) | The origin server does not support, or refuses to support, the major version of HTTP that was used in the request message.

When a web server determines that a user agent should not receive certain information, the web server must choose the status code and the contents of a Status Report carefully. For example, local policy may dictate that the web service returns a 404 (Not Found) rather than a 401 (Unauthorized) status code to avoid allowing the user agent to infer the existence of a resource. The status code and payload of the response needs to be controlled by policy and context, balancing usability of the returned result against appropriate protection. See also [FHIR Access Denied] and [OWASP Information Leakage].

## 8.6 Payloads

Both request and response messages may have message bodies. The message body (if any) of an HTTP message is used to carry the payload of the message. The message body is identical to the payload unless a content coding has been applied, as described in [RFC7230] Section 3.3.1. This Part of the Standard uses the term "payload" to denote the message body before any content coding has been applied to it.

A message may or may not have a payload. A payload may be empty; that is, its length is zero. If a message has no payload, then the message shall have neither Content-Encoding nor Content-Length header fields. If a message has a payload to which a transfer-coding has been applied, then the message shall have a Content-Encoding header field. If a message has a payload that has not had a transfer-coding applied, then the message shall have a Content-Length header field.

Any message containing a payload shall have appropriate Content Representation [RFC7231] Section 3.1 and Payload Header Fields [RFC7231] Section 3.3. Any message with a payload shall have a Content-Type header field that specifies the media type of the representation contained in the payload. The media type specifies whether the payload is single part or multipart (see Section 8.7). Any message with a payload should include a Content-Location header field. See [RFC7231] Section 3.1.2.2.

### 8.6.1 Payload Format

Payloads may be in either single part or multipart format depending on the media type.

#### 8.6.1.1 Single Part Payload

A single part payload contains one representation that is described by the Content Representation Header Fields (see Section 8.4.3) contained in the message header. A message with a single part payload shall have a Content-Type header field with a single part media-type.

#### 8.6.1.2 Multipart Payload

A message with a multipart payload contains one or more representations. The media type of the root representation (see [RFC2387]) may be specified by the Content-Type header field of the message. If no root parameter is specified, then the root representation is the first representation in the payload.

Each part in a multipart payload shall start with a boundary string, followed by a Content-Type header field. See Table 8.6.1-1 for other header fields occurring in multipart payloads.

Table 8.6.1-1. Multipart Header Fields

Name | Value | Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M |
Content-Encoding | encoding | C | Shall be present if the response payload has a content encoding
Content-Length | int | C | Shall be present if the response payload does not have a content encoding
Content-Location | url | C | Shall be present if the response payload contains a representation of a resource. See [RFC7231] Section 3.1.4.2.
Location | url | C | See [RFC7231] Section 7.1.2.

See Section 8.7.1 and [RFC7231].

The following is an example template of a multipart request or response message that has a multipart payload:

    request-line / response-line

    Content-Type: multipart-media-type CRLF

    Content-Location: "/" {/url} CRLF

    *(header-field CRLF)

    CRLF

    multipart-payload

The Content-Type header field shall have a multipart media-type. For example:

    Content-Type: multipart/related; type=DQ root-media-type DQ; boundary="---boundary---"

Where

    multipart-media-type
| is a media type defined by [RFC2387].
    root-media-type
| is a single part media type that specifies the media type of the root, typically the first part, in the payload. If the value of the type parameter and the root body part's content-type differ then the user agent's behavior is undefined.
    boundary
| specifies a string that acts as a boundary between message parts.

Each part in a multipart payload shall start with a Boundary header field, followed by a Content-Type header field. Other header fields may be included, such as Content-Location, and either the Content-Length or Content-Encoding header field, optionally followed by other header fields.

If a multipart payload contains Metadata (see Section 8.7.3.3.1), and Bulkdata (see Section 8.7.3.3.2), then all Metadata message parts that reference a Bulkdata part shall precede the referenced Bulkdata part.

##### 8.6.1.2.1 Multipart Payload Syntax

The syntax of a multipart payload is:

    multipart-payload = 1*(DASH boundary CRLF part CRLF) DASH boundary DASH

Where

    DASH         = "--"
    boundary     = 0*69(bchar / SP) bchar
    bchar        = DIGIT / ALPHA / "'" / "(" / ")" / "+" / "_"   ; The legal boundary characters
                 / "," / "-" / "." / "/" / ":" / "=" / "?"
    part         = Content-Type: media-type CRLF
                   Content-Location: url CRLF
                   (Content-Length: uint CRLF / Content-Encoding: encoding CRLF)
                   [Content-Description: text CRLF]
                   *(header-field CRLF)
                   CRLF
                   part-payload
    part-payload = *OCTET

For example, if the boundary is "++++", then a message payload containing three parts would be structured as follows:

    --++++CRLF

    Content-Type: media-type CRLF

    Content-Location: url CRLF

    (Content-Length: uint CRLF / Content-Encoding: encoding CRLF)

    [Content-Description: {description} CRLF]

    CRLF

    payload CRLF

    --++++CRLF

    Content-Type: media-type CRLF

    . . .

    payload CRLF

    --++++CRLF

    Content-Type: media-type CRLF

    . . .

    payload CRLF

    --++++--

Figure 8.6-1 shows the correspondence between the IOD representation and a multipart payload.

Figure 8.6-1. Mapping between IOD and HTTP message parts

### 8.6.2 DICOM Representations

All DICOM objects are defined by Information Object Definitions (IODs). See PS3.3. Representations of DICOM Resources are encodings of DICOM Information Objects into octet streams.

Each IOD has an associated set of Attributes, which define semantic concepts. Each Attribute has:

- a Tag, which identifies the Attribute using an integer

- a Keyword, which identifies the Attribute using a token

- a Type, which indicates whether the Attribute is required or optional

- a Value Representation, which defines the data type of the Attribute's value(s)

- a Value Multiplicity, which specifies the number of values that the Attribute may have

A Data Element is a concrete representation of an Attribute See PS3.5. Each Data Element has:

- an identifier, which would typically be its Tag, but could be its Keyword

- a Value Representation, which defines its data type

- a Value Length

- a Value Field, which is a sequence of bytes containing zero or more values

Each Instance contains Data Elements representing the Attributes from the Patient, Study, Series, and Instance levels of the IOD. For example, if a Series resource contains 12 Instances, then a transaction that retrieves that Series will contain a representation of the Series and its 12 Instances, in a specific media type, and each Instance will have Patient, Study, Series, and Instance level Attributes.

This Part of the Standard defines three distinct representations of DICOM Resources that can be encoded into DICOM Media Types: Instances, Metadata, and Bulkdata.

DICOM Media Types and their corresponding representations are defined in Section 8.7.3. Other media types used in this Part of the Standard are defined in Section 8.7.4.

#### 8.6.2.1 Web Service Constraints

DICOM Web Services only support representations with explicit Value Representations. Implicit Value Representations (see Section 7.1.3 “Data Element Structure with Implicit VR” in PS3.5) shall not be used.

### 8.6.3 Status Report

A Status Report is a description of warnings or errors encountered by the origin server in processing a request. The contents should be clear and succinct. If the request does not include an Acceptable Media Type, the Status Report should use the default media type for the Text Resource Category, which is text/html.

## 8.7 Media Types

Media types are the basis for both content negotiation and data typing of message payloads. Each PS3.18 service, and/or transaction defines the media types and associated representations that are default, required and optional.

The media type also specifies whether the payload contains a single representation (single part), or multiple representations (multipart). Multipart payloads are only defined for the RESTful APIs. See Section 8.6.1.2 and Section 10.4.3.

Media types are identifiers used to define the data format of a representation. HTTP uses media types in the Content-Type and Accept header fields to provide open and extensible data typing and type negotiation. The syntax of media types is:

    media-type = type "/" subtype *(OWS ";" OWS mt-parameter)

Where

    type         = token
    subtype      = token
    mt-parameter = mtp-name "=" mtp-value
    mtp-name     = token
    mtp-value    = (token / quoted-string)

The 'type/subtype' may be followed by parameters in the form of 'name "=" value' pairs.

The type, subtype, and mtp-name tokens are case-insensitive, but the case sensitivity of parameter values depends on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing of a media-type, depending on its definition within the media type registry.

An mtp-value can be transmitted either as a token or quoted-string. The quoted and unquoted values are equivalent.

Media types are defined in [RFC7231] Section 3.1.1.1.

IANA maintains a registry of media types [IANA Media Types].

Many media types specify a character set parameter.

### Note

The term "MIME Type" is not synonymous with "Media Type". MIME types are defined by Multipurpose Internet Mail Extensions [RFC2045] and used by email programs. Media Types are defined by Media Type Specifications and Registration Procedures [RFC6838].

### 8.7.1 Multipart Media Types

Some of the services defined in this Part of the Standard support the multipart media types [RFC2387]. The syntax is:

    multipart-media-type = "multipart" "/" subtype *(OWS ";" OWS parameter)

The application/multipart-related media type is used by the RESTful services. Its syntax is:

    multipart-related = "multipart/related"
                        OWS ";" OWS "type" "=" DQ media-type DQ
                        OWS ";" OWS "boundary" "=" boundary
                        [related-parameters]

Where

    boundary           ; See Section 8.6.1.2.1

    bchar              = bchar-nospace / SP
    bchar-nospace      = DIGIT / ALPHA / "'" / "(" / ")" / "+" / "_" / "," / "-"
                         / "." / "/" / ":" / "=" / "?" "/" / ":" / "=" / "?"
    related-parameters = [";" "start" "=" cid]
                         [";" "start-info" "=" cid-list]
    cid-list           = cid cid-list
    cid                = token / quoted-string

The "type" parameter is required. It contains the media type of the "root" body part. It always contains the special character "/" and thus requires quote marks.

The cid is a content identifier. It should be unique for each part of the multipart message.

Typically, the "start" and "start-info" parameters are not specified, and the "root" is the first body part.

### 8.7.2 DICOM Resource Categories

Table 8.7.2-1 defines Resource Categories that correspond to different SOP Classes. The following sections map each Resource Category to appropriate DICOM and Rendered media types.

Table 8.7.2-1. Resource Categories

Resource Category | Definition
--- | ---
Single Frame Image | This category includes all resources that are: Instances of a single frame SOP Class, or Instances of a multi-frame SOP Class that contain only one frame, or a single frame selected from an Instance of a multi-frame SOP Class.
Multi-Frame Image | This category includes all resources that are Instances of a multi-frame SOP Class, that are not Video and that contain more than one frame.
Video | This category includes all resources that contain more than one frame and are: Instances encoded in the MPEG family of Transfer Syntaxes (which includes MP4 and H.265), or time-based (motion) multi-frame images that the origin server is capable of encoding in the MPEG family.
Text | This category includes all resources that contain: the SR Document Content Module (see Section C.17.3 “SR Document Content Module” in PS3.3), such as narrative text, Structured Reports, CAD, measurement reports, and key object selection documents, or the Encapsulated Document Module (see Section C.24.2 “Encapsulated Document Module” in PS3.3).
Other | This category includes all resources that are not included above, for example waveforms.

### 8.7.3 DICOM Media Types and Media Types For Bulkdata

This section defines the media types used to represent DICOM Instances, Metadata and Bulkdata. It describes:

- The media type and Transfer Syntax parameters for DICOM PS3.10 Instances

- The media types that can be used for Metadata

- The media types and Transfer Syntaxes parameters for Bulkdata

- The syntax of DICOM Media Types including their Transfer Syntax and character set parameters

- The Query Parameter for Transfer Syntax

- The meaning of Acceptable Transfer Syntaxes and Selected Transfer Syntax

The media types defined in this section are distinct from those into which DICOM Instances may be rendered (which are defined in Section 8.7.4); some of the same media types are used for both rendered content and Bulkdata.

Depending on the service, the media types may be single part or multipart, and may have required or optional Transfer Syntax and/or character set parameters.

The Implicit VR Little Endian (1.2.840.10008.1.2), and Explicit VR Big Endian (1.2.840.10008.1.2.2 - Retired) Transfer Syntaxes shall not be used with Web Services.

If a Transfer Syntax parameter for a DICOM Media Type is not specified in a request or response, the Transfer Syntax in the response shall be the Transfer Syntax specified as the default for the Resource Category and media type combination in Table 8.7.3-2, Table 8.7.3-4 or Table 8.7.3-5.

Table 8.7.3-1 specifies the definition of media type requirement terms used in the tables in this section.

Table 8.7.3-1. Definition of Media Type Requirement

Requirement | Optionality | Definition
--- | --- | ---
Default | D | The origin server shall return this media type when none of the Acceptable Media Types (see Section 8.7.5) are supported. The origin server shall support this media type.
Required | R | The origin server shall support this media type.
Optional | O | The origin server may support this media types.

Table 8.7.3-2, Table 8.7.3-3, Table 8.7.3-4, and Table 8.7.3-5 specify the media types used to encode different representations of DICOM Instances. These media types apply to all Resource Categories and have default encodings for images and video data elements contained in the Instances.

#### 8.7.3.1 The application/dicom Media Type

The application/dicom media type specifies a representation of Instances encoded in the DICOM File Format specified in Section 7 “DICOM File Format” in PS3.10.

Table 8.7.3-2 specifies the default and optional Transfer Syntax UID combinations for each DICOM Resource Category (see Table 8.7.2-1). The default media type for the Resource Category shall be returned when the origin server supports none of the Acceptable Media Types.

Table 8.7.3-2. Transfer Syntax UIDs for application/dicom Media Types

Category | Transfer Syntax UID | Transfer Syntax Name | Optionality
--- | --- | --- | ---
Single Frame Image | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
1.2.840.10008.1.2.4.70 | JPEG Lossless, Non-Hierarchical, First-Order Prediction(Process 14 [Selection Value 1]): Default Transfer Syntax for Lossless JPEG Image Compression | O
1.2.840.10008.1.2.4.50 | JPEG Baseline (Process 1): Default Transfer Syntax for Lossy JPEG 8 Bit Image Compression | O
1.2.840.10008.1.2.4.51 | JPEG Extended (Process 2 & 4): Default Transfer Syntax for Lossy JPEG 12 Bit Image Compression (Process 4 only) | O
1.2.840.10008.1.2.4.57 | JPEG Lossless, Non-Hierarchical (Process 14) | O
1.2.840.10008.1.2.5 | RLE Lossless | O
1.2.840.10008.1.2.4.80 | JPEG-LS Lossless Image Compression | O
1.2.840.10008.1.2.4.81 | JPEG-LS Lossy (Near-Lossless) Image Compression | O
1.2.840.10008.1.2.4.90 | JPEG 2000 Image Compression (Lossless Only) | O
1.2.840.10008.1.2.4.91 | JPEG 2000 Image Compression | O
1.2.840.10008.1.2.4.92 | JPEG 2000 Part 2 Multi-component Image Compression (Lossless Only) | O
1.2.840.10008.1.2.4.93 | JPEG 2000 Part 2 Multi-component Image Compression | O
Multi-frame Image | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
1.2.840.10008.1.2.4.90 | JPEG 2000 Image Compression (Lossless Only) | O
1.2.840.10008.1.2.4.91 | JPEG 2000 Image Compression | O
1.2.840.10008.1.2.4.92 | JPEG 2000 Part 2 Multi-component Image Compression (Lossless Only) | O
1.2.840.10008.1.2.4.93 | JPEG 2000 Part 2 Multi-component Image Compression | O
Video | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
1.2.840.10008.1.2.4.100 | MPEG2 Main Profile @ Main Level | O
1.2.840.10008.1.2.4.101 | MPEG2 Main Profile @ High Level | O
1.2.840.10008.1.2.4.102 | MPEG-4 AVC/H.264 High Profile / Level 4.1 | O
1.2.840.10008.1.2.4.103 | MPEG-4 AVC/H.264 BD-compatible High Profile / Level 4.1 | O
1.2.840.10008.1.2.4.104 | MPEG-4 AVC/H.264 High Profile / Level 4.2 For 2D Video | O
1.2.840.10008.1.2.4.105 | MPEG-4 AVC/H.264 High Profile / Level 4.2 For 3D Video | O
1.2.840.10008.1.2.4.106 | MPEG-4 AVC/H.264 Stereo High Profile / Level 4.2 | O
Text | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Other | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D

#### 8.7.3.2 DICOM Metadata Media Types

Table 8.7.3-3 specifies the media types that may be used to encode representations of Metadata for the URI and RESTful services. Only the RESTful Services support Metadata representations.

Table 8.7.3-3. Media Types for Metadata

Media Type | Descriptions | URI | RESTful
--- | --- | --- | ---
application/dicom+xml | Encodes Instances as XML Infosets defined in the Native DICOM Model defined in PS3.19. | not applicable | required
application/dicom+json | Encodes Instances in the JSON format defined in Annex F. | not applicable | required

#### 8.7.3.3 DICOM Bulkdata Media Types

Bulkdata representations are only supported by RESTful services. There are two categories of Bulkdata: uncompressed and compressed.

The default media type for the Resource Category shall be returned when the origin server supports none of the Acceptable Media Types.

The origin server may support additional Transfer Syntaxes.

If no media type Transfer Syntax parameter is specified, then the Explicit VR Little Endian Transfer Syntax "1.2.840.10008.1.2.1" shall be used.

### Note

The tables in this section have no entries for the URI service, since they do not support separate retrieval of Bulkdata.

##### 8.7.3.3.1 Uncompressed Bulkdata

Table 8.7.3-4 specifies the default media type and Transfer Syntax UIDs, by Resource Category (see Table 8.7.2-1) that can be used with uncompressed Bulkdata for the RESTful services. Uncompressed Bulkdata is encoded as a stream of uncompressed bytes (octets) in Little Endian byte order.

### Note

This is the same encoding defined in PS3.19 for the returned value of the getData() call for uncompressed Bulkdata.

Table 8.7.3-4. Transfer Syntax UIDs for Uncompressed Data in Bulkdata

Category | Media Type | Transfer Syntax UID | Transfer Syntax Name | RESTful
--- | --- | --- | --- | ---
Single Frame Image | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Multi-Frame Image | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Video | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Text | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D
Other | application/octet-stream | 1.2.840.10008.1.2.1 | Explicit VR Little Endian | D

### Note

Even though the Transfer Syntax is Explicit VR Little Endian, the Value Representation is not actually encoded at the beginning of the octet-stream. The Value Representation is contained in the Metadata that references the Bulkdata.

##### 8.7.3.3.2 Compressed Bulkdata

Compressed Bulkdata contains only the compressed octet stream without the fragment delimiters.

Table 8.7.3-5 specifies the default and optional media types and Transfer Syntax UID combinations for each Resource Category (see Table 8.7.2-1) of compressed Bulkdata for the RESTful services.

### Note

Some of the Transfer Syntax Names include text about Default Transfer Syntax, however this applies to its role in DIMSE transactions, rather than the default for RESTful services (which is specified in the RESTful column of the table).

These media types can be used to retrieve Bulkdata, such as images or video, encoded in a specific Transfer Syntax.

Table 8.7.3-5. Media Types and Transfer Syntax UIDs for Compressed Data in Bulkdata

Category | Media Type | Transfer Syntax UID | Transfer Syntax Name | Optionality
--- | --- | --- | --- | ---
Single Frame Image | image/jpeg | 1.2.840.10008.1.2.4.70 | JPEG Lossless, Non-Hierarchical, First-Order Prediction(Process 14 [Selection Value 1]) :Default Transfer Syntax for Lossless JPEG Image Compression | D
1.2.840.10008.1.2.4.50 | JPEG Baseline (Process 1) :Default Transfer Syntax for Lossy JPEG 8 Bit Image Compression | O
1.2.840.10008.1.2.4.51 | JPEG Extended (Process 2 & 4) :Default Transfer Syntax for Lossy JPEG 12 Bit Image Compression (Process 4 only) | O
1.2.840.10008.1.2.4.57 | JPEG Lossless, Non-Hierarchical (Process 14) | O
image/dicom-rle | 1.2.840.10008.1.2.5 | RLE Lossless | D
image/jls | 1.2.840.10008.1.2.4.80 | JPEG-LS Lossless Image Compression | D
1.2.840.10008.1.2.4.81 | JPEG-LS Lossy (Near-Lossless) Image Compression | O
image/jp2 | 1.2.840.10008.1.2.4.90 | JPEG 2000 Image Compression (Lossless Only) | D
1.2.840.10008.1.2.4.91 | JPEG 2000 Image Compression | O
image/jpx | 1.2.840.10008.1.2.4.92 | JPEG 2000 Part 2 Multi-component Image Compression (Lossless Only) | D
1.2.840.10008.1.2.4.93 | JPEG 2000 Part 2 Multi-component Image Compression | O
Multi-frame Image | image/jpeg | 1.2.840.10008.1.2.4.70 | JPEG Lossless, Non-Hierarchical, First-Order Prediction(Process 14 [Selection Value 1]) :Default Transfer Syntax for Lossless JPEG Image Compression | D
1.2.840.10008.1.2.4.50 | JPEG Baseline (Process 1) :Default Transfer Syntax for Lossy JPEG 8 Bit Image Compression | O
1.2.840.10008.1.2.4.51 | JPEG Extended (Process 2 & 4) :Default Transfer Syntax for Lossy JPEG 12 Bit Image Compression (Process 4 only) | O
1.2.840.10008.1.2.4.57 | JPEG Lossless, Non-Hierarchical (Process 14) | O
image/dicom-rle | 1.2.840.10008.1.2.5 | RLE Lossless | D
image/jls | 1.2.840.10008.1.2.4.80 | JPEG-LS Lossless Image Compression | D
1.2.840.10008.1.2.4.81 | JPEG-LS Lossy (Near-Lossless) Image Compression | O
image/jp2 | 1.2.840.10008.1.2.4.90 | JPEG 2000 Image Compression (Lossless Only) | D
1.2.840.10008.1.2.4.91 | JPEG 2000 Image Compression | O
image/jpx | 1.2.840.10008.1.2.4.92 | JPEG 2000 Part 2 Multi-component Image Compression (Lossless Only) | D
1.2.840.10008.1.2.4.93 | JPEG 2000 Part 2 Multi-component Image Compression | O
Video | video/mpeg2 | 1.2.840.10008.1.2.4.100 | MPEG2 Main Profile @ Main Level | O
1.2.840.10008.1.2.4.101 | MPEG2 Main Profile @ High Level | D
video/mp4 | 1.2.840.10008.1.2.4.102 | MPEG-4 AVC/H.264 High Profile / Level 4.1 | D
1.2.840.10008.1.2.4.103 | MPEG-4 AVC/H.264 BD-compatible High Profile / Level 4.1 | O
1.2.840.10008.1.2.4.104 | MPEG-4 AVC/H.264 High Profile / Level 4.2 For 2D Video | O
1.2.840.10008.1.2.4.105 | MPEG-4 AVC/H.264 High Profile / Level 4.2 For 3D Video | O
1.2.840.10008.1.2.4.106 | MPEG-4 AVC/H.264 Stereo High Profile / Level 4.2 | O
Text |  | N/A (no defined compression transfer syntaxes for Text) |
Other |  | N/A (no defined compression transfer syntaxes for Other) |

The origin server may support additional Transfer Syntaxes.

### Note

1. For the media type image/jpeg Transfer Syntaxes, the image may or may not include the JFIF marker segment. The image may or may not include APP2 marker segments with an identifier of "ICC_PROFILE". There is no requirement for the origin server to add a JFIF marker segment nor to copy the value of the ICC Profile (0028,2000) Attribute, if present, into APP2 marker segments in the compressed data stream. See Section 8.2.1 “JPEG Image Compression” in PS3.5.

2. For the media type image/jp2 and image/jpx Transfer Syntaxes, the image does not include the jp2 marker segment. See Section 8.2.4 “JPEG 2000 Image Compression” in PS3.5 and Section A.4.4 “JPEG 2000 Image Compression” in PS3.5

3. The resource on the origin server may have been encoded in the Deflated Explicit VR Little Endian (1.2.840.10008.1.2.1.99) Transfer Syntax. If so, the origin server may inflate it, and then convert it into an Acceptable Transfer Syntax. Alternatively, if the user agent allowed a Content-Encoding header field of 'deflate', then the deflated bytes may be transferred unaltered, but the Transfer Syntax parameter in the response should be the Explicit VR Little Endian Transfer Syntax.

4. Compressed multi-frame image Bulkdata is encoded as one frame per part. E.g., each frame of a JPEG 2000 multi-frame image will be encoded as a separate part with an image/jp2 media type, rather than as a single part with a video/mj2 ([RFC3745]) or uncompressed application/octet-stream media type.

5. Video Bulkdata is encoded as a single part containing all frames. E.g., all frames of an MPEG-4 video will be encoded as a single part with a video/mp4 ([RFC_4337]) media type.

6. Many of the media types used for compressed Pixel Data transferred as Bulkdata values are also used for consumer format media types. A web browser may not be able to display the encoded data directly, even though some of the same media types are also used for encoding rendered Pixel Data. See Section 8.7.4.

   For example, the media type for Bulkdata values of lossless 16-bit JPEG [ISO/IEC 10918-1] encoded Pixel Data is "image/jpeg", the same media type as might be used for 8-bit JPEG [ISO/IEC 10918-1] encoded Pixel Data, whether extracted as Bulkdata, or rendered. The Transfer Syntax parameter of the Content-Type header field is useful to signal the difference.

7. Each part of a multipart response is distinguished by the Content-Type and Content-Location header fields of the part.

8. Previously, experimental Media Types "image/x-dicom-rle" and "image/x-jls" were defined, so origin servers and user agents may want to account for these when communicating with older implementations. These have been replaced with the standard Media Types "image/dicom-rle" and "image/jls", respectively.

#### 8.7.3.4 Transfer Syntax

The Default Transfer Syntax for DICOM objects contained in a payload shall be Explicit VR Little Endian Uncompressed "1.2.840.10008.1.2.1". If the Transfer Syntax is not specified in a message, then the Default Transfer Syntax shall be used.

### Note

This is different from the Default Transfer Syntax defined in Section 10.1 “DICOM Default Transfer Syntax” in PS3.5, which is Implicit VR Little Endian.

Implicit VR Little Endian, or Explicit VR Big Endian shall not be used.

The response payload encoding requirements are defined in Section 8.7.8.

### Note

The transfer syntax can be one of the JPIP Transfer Syntaxes, in which case the returned objects will contain the URL of the JPIP provider for retrieving the pixel data.

The origin server may support additional Transfer Syntaxes.

#### 8.7.3.5 DICOM Media Type Syntax

The syntax of DICOM Media Types is:

    dicom-media-type = (dcm-singlepart / dcm-multipart) [dcm-parameters]

Where

    dcm-singlepart = dcm-mt-name

    dcm-multipart  ;see Section 8.7.3.5.1

    dcm-parameters = transfer-syntax-mtp ;see Section 8.7.3.5.2

                   / charset-mtp;see Section 8.7.3.5.3

    dcm-mt-name    = dicom / dicom-xml / dicom-json ;DICOM Media Type name

    dicom          = "application/dicom"

    dicom-xml      = "application/dicom+xml"

    dicom-json     = "application/dicom+json"

    octet-stream   = "application/octet-stream"

All DICOM Media Types may have a Transfer Syntax parameter, but its usage may be constrained by the service for which they are used.

### Note

The application/dicom+xml and application/dicom+json Media Types may have a Transfer Syntax parameter in order to specify the encoding of base64 data.

All DICOM Media Types may have a character set parameter, but its usage may be constrained by the service for which they are used.

##### 8.7.3.5.1 DICOM Multipart Media Types

The syntax of multipart media types is:

    dcm-multipart = "multipart/related"

                    OWS ";" OWS "type" "=" dcm-mp-mt-name

                    OWS ";" OWS "boundary=" boundary

                    [dcm-parameters]

                    [related-parameters]

Where

    dcm-mp-mt-name = dicom / dicom-xml / dicom-json / octet-stream

See Section 8.6.1.2.1 for the definition of boundary and related-parameters.

Each multipart media type shall include a "type" parameter that defines the media type of the parts and shall also include a "boundary" parameter that specifies the boundary string that is used to separate the parts.

##### 8.7.3.5.2 Transfer Syntax Parameter

For a given DICOM Media Type, a single Transfer Syntax parameter value may be specified, but its usage may be constrained by the service for which they are used.

RESTful origin servers shall support the Transfer Syntax parameter.

Transfer syntax media type parameters are forbidden in URI Service requests and responses.

The syntax is:

    transfer-syntax-mtp = OWS ";" OWS %s"transfer-syntax=" ts-value

    ts-value            = transfer-syntax-uid / "*"

    transfer-syntax-uid ; a UID from Table A-1 “UID Values” in PS3.6 with a UID Type of Transfer Syntax

The value of the Transfer Syntax parameter may be either a Transfer Syntax UID or the token "*".

For example, to specify that 1.2.840.10008.1.2.4.50 is the acceptable Transfer Syntaxes, an Accept header field could be:

    Accept: application/dicom; transfer-syntax=1.2.840.10008.1.2.4.50

A DICOM Media Type may only have one Transfer Syntax parameter and it shall have only one value.

### Note

Per [RFC6838] Media Type Specifications and Registration Procedures, it is an error for a specific parameter to be specified more than once. If a choice of Transfer Syntaxes is acceptable. more than one media type may be provided in the Accept header with different q parameter values to indicate preference. E.g., to specify that 1.2.840.10008.1.2.4.50 and to specify that 1.2.840.10008.1.2.4.57 are acceptable but 1.2.840.10008.1.2.4.50 is preferred, an Accept header field could be:

    Accept: multipart/related; type="application/dicom";transfer-syntax=1.2.840.10008.1.2.4.50;boundary=**, multipart/related; type="application/dicom";transfer-syntax=1.2.840.10008.1.2.4.57;q=0.5;boundary=**

The wildcard value "*" indicates that the user agent will accept any Transfer Syntax. This allows, for example, the origin server to respond without needing to transcode an existing representation to a new Transfer Syntax, or to respond with the Explicit VR Little Endian Transfer Syntax regardless of the Transfer Syntax stored.

If an Origin server supports the Transfer Syntax parameter, it shall support the wildcard value.

Origin servers that support the Transfer Syntax parameter shall specify in their Conformance Statement those values of Transfer Syntax parameter that are supported in the response.

User agents that support the Transfer Syntax parameter shall specify in their Conformance Statement those Transfer Syntax parameter values that may be supplied in the request.

##### 8.7.3.5.3 Character Set Parameter

All DICOM Media Types may have a single Character Set parameter, which shall have only a single value, that specifies the Acceptable Character Set for the response.

The syntax is:

    charset-mtp = OWS ";" OWS %s"charset" "=" charset

All DICOM Media Types have a Default Character Set of UTF-8. See Section 8.8 for character set details.

#### 8.7.3.6 Transfer Syntax Query Parameter

The Transfer Syntax Query Parameter specifies a comma-separated list of one or more Transfer Syntax UIDs, as defined in PS3.6.

The syntax is:

    transfer-syntax-qp = %s"transferSyntax" "=" (1#transfer-syntax-uid / "*")

This Query Parameter is only used by the URI Service.

RESTful services specify the Transfer Syntax in the "accept" Query Parameter (see Section 8.3.3.1) and do not use Transfer Syntax Query Parameter.

#### 8.7.3.7 Acceptable Transfer Syntaxes

Each DICOM Media Type in the Acceptable Media Types has an Acceptable Transfer Syntax, which is explicitly specified or has a default value.

Depending on the service, the Acceptable Transfer Syntax for a DICOM Media Type can be specified in the:

1. Transfer Syntax media type parameter contained in the Accept Query Parameter (see Section 8.3.3.1)

2. Transfer Syntax media type parameter contained in the Accept header field

3. Transfer Syntax Query Parameter (see Section 8.7.3.5)

### 8.7.4 Rendered Media Types

DICOM Instances may be converted by a rendering process into non-DICOM Media Types. This can be useful to display or process them using non-DICOM software, such as browsers.

For example, an Instance containing:

1. an image could be rendered into the image/jpeg or image/png Rendered Media Types.

2. a multi-frame image in a lossless Transfer Syntax could be rendered into a video/mpeg or video/mp4 Rendered Media Type.

3. a Structured Report could be rendered into a text/html, text/plain, or application/pdf Rendered Media Type.

### Note

Rendered Media Types are usually consumer format media types. Some of the same non-DICOM Media Types are also used as Bulkdata Media Types, that is, for encoding Bulkdata extracted from Encapsulated Pixel Data (used with compressed Transfer Syntaxes), without applying a rendering process. See Section 8.7.3.3.

Rendered images shall contain no more than 8 bits per channel.

Origin servers shall support rendering Instances of different Resource Categories into Rendered Media Types as specified in Table 8.7.4-1.

Table 8.7.4-1. Rendered Media Types by Resource Category

Category | Media Type | URI | RESTful
--- | --- | --- | ---
Single Frame Image | image/jpeg | D | D
image/gif | O | R
image/png | O | R
image/jp2 | O | O
Multi-frame Image | image/gif | O | O
Video | video/mpeg | O | O
video/mp4 | O | O
video/H265 | O | O
Text | text/html | D | D
text/plain | R | R
text/xml | O | R
text/rtf | O | O
application/pdf | O | O

When an image/jpeg media type is returned, the image shall be encoded using the JPEG baseline lossy 8-bit Huffman encoded non-hierarchical non-sequential process defined in [ISO/IEC 10918-1].

The origin server may support additional Rendered Media Types, which shall be documented in the Conformance Statement and, if the service supports it, the Retrieve Capabilities response.

A Transfer Syntax media type parameter is not permitted for Rendered Media Types.

### 8.7.5 Acceptable Media Types

The term Acceptable Media Types denotes the media types that are acceptable to the user agent in the response. The Acceptable Media Types are those specified in:

- The Accept Query Parameter, which may or may not be present.

- The Accept header field, which shall be present.

The response to a request without an Accept header field shall be 406 (Not Acceptable). The presence of an Accept Query Parameter does not eliminate the need for an Accept header field. For details see Section 8.3.3.1.

The Acceptable Media Types shall be either DICOM media-types or Rendered media types, but not both. If the Acceptable Media Types contains both DICOM and Rendered Media Types, the origin server shall return 400 (Bad Request).

The user agent may specify the relative degree of preference for media types, whether in the Accept Query Parameter or the Accept header field, using the weight parameter. See [RFC7231] Section 5.3.1.

    weight = OWS ";" OWS "q=" qvalue

    qvalue = ("0" ["." 0*3DIGIT]) / ("1" ["." 0*3("0") ])

If no "q" parameter is present, the default qvalue is 1.

### 8.7.6 Accept Query Parameter

The Accept Query Parameter can be used to specify Acceptable Media Types. See Section 8.7.5.

### 8.7.7 Accept Header Field

The Accept header field is used to specify media types acceptable to the user agent. It has the following syntax:

    Accept = 1#(media-range [weight])

The Accept header field value shall be a comma-separated list of one or more media ranges acceptable in the response. See [RFC7231] Section 5.3.2.

A media range is either a media-type or a wildcard. Wildcards use the asterisk ("*") to group media types into ranges, with <type>/* indicating all subtypes of that type, and */* indicating all media types. For example, the media range image/* matches image/jpeg, which is the default media type for the Single Frame Image Resource Category, and text/* matches text/html, which is the default media type for the Text Resource Category. DICOM specifies that the */* media range matches the default media type for the target's Resource Category. If no default media type is defined for a Resource Category, then any media type from the Resource Category is acceptable.

If the response might contain a payload, an Accept header field shall be present in the request.

If the origin server receives a request without an Accept header field, but that might have a response payload, it shall return a 406 (Not Acceptable).

Any Accept header field values, including media type parameters, that are not valid or not supported shall be ignored by the origin server.

### 8.7.8 Selected Media Type and Transfer Syntax

The selection of the media type and transfer syntax by the origin server are interrelated.

#### 8.7.8.1 Selected Media Type

The Selected Media Type is the media type selected by the origin server for the response payload. The media types in the Accept Query Parameter and the media ranges in the Accept header field shall each be separately prioritized according to the rules defined in [RFC7231] Section 5.3.1.

For multipart payloads, the Selected Media Type is determined independently for each message part in the response.

### Note

The Selected Media Type of each message part depends on the Resource Category of the Instance and the Acceptable Media Types for that Resource Category.

The Selected Media Type of each message part depends on the Resource Category of the Instance and the Acceptable Media Types for that Resource Category.

The Selected Media Type is chosen as follows:

1. Identify the target's Resource Category

2. Select the representation with the highest priority supported media type for that category in the Accept Query Parameter.

3. If no media type in the Accept Query Parameter is supported, select the highest priority supported media type for that category in the Accept header field, if any.

4. Otherwise, select the default media type for the category, if the Accept header field contains a wildcard media range matching the category, if any.

5. Otherwise, return a 406 (Not Acceptable).

### Note

1. If the Selected Media Type is the Explicit VR Little Endian and the pixel data is compressed and when uncompressed is of such length that it cannot contained in a value field, then the origin server will respond with a 406 (Not Acceptable), and the user agent may try again with a different set of Acceptable Media Types.

2. If transcoding to the Explicit VR Little Endian Transfer Syntax, a VR of UN may be needed for the encoding of Data Elements with explicit VR whose value length exceeds 65534 (216-2) (FFFEH, the largest even length unsigned 16-bit number) but which are defined to have a 16-bit explicit VR length field. See Section 6.2.2 “Unknown (UN) Value Representation” in PS3.5.

For a set of media types in the Accept Query Parameter (step 2 above), or for a set of media ranges in the Accept header field (step 3 above), the highest priority supported media type is determined as follows:

1. Assign a qvalue of 1 to any member of the set that does not have a one.

2. Assign each representation supported by the origin server the qvalue of the most specific media type that it matches.

3. Select the representation with the highest qvalue. If there is a tie, the origin server shall determine which is returned.

For example, consider an origin server which receives a request with the following Accept header field:

    Accept: text/*; q=0.5, text/html; q=0.4, text/html; level=1, text/html; level=2; q=0.7,

            image/png, */*; q=0.4

Suppose that for the resource indicated in the request, the origin server supports representations for the following media types:

    text/html (regular, level 1 and level 2)

    text/rtf

    text/plain

    text/x-latex

These media types are assigned the following qvalues, based on the media ranges above:

Table 8.7.8-1. Media Type QValue Example

Media Type | qvalue | Determining Media Range
--- | --- | ---
text/html; level=1 | 1.0 | text/html; level=1
text/html; level=2 | 0.7 | text/html; level=2
text/plain | 0.5 | text/*
text/rtf | 0.5 | text/*
text/html | 0.4 | text/html
text/x-latex | 0.4 | */*

Although "image/png" has been assigned a default qvalue of 1.0, it is not among the supported media types for this resource, and thus is not listed.

The selected media type is 'text/html; level=1' since it is the supported media type in the Text Category with the highest qvalue.

#### 8.7.8.2 Selected Transfer Syntax

The Selected Transfer Syntax is the Transfer Syntax selected by the origin server to encode a single message part in the response.

The origin server shall first determine the Selected Media Type as defined in Section 8.7.8 and then determine the Selected Transfer Syntax.

If the Selected Media Type was contained in the Accept Query Parameter, then the Selected Transfer Syntax is determined as follows:

1. Select the value of the Transfer Syntax parameter of the Selected Media Type, if any;

2. Otherwise, select the value of the Transfer Syntax in the Transfer Syntax Query Parameter, if any;

3. Otherwise select the default Transfer Syntax (see Table 8.7.3-2, Table 8.7.3-4 or Table 8.7.3-5) for the Selected Media Type.

If the Selected Media Type was contained in the Accept header field, then the Selected Transfer Syntax is determined as follows:

1. Select the Transfer Syntax parameter for the Selected Media Type, if any;

2. Otherwise, select the default Transfer Syntax for the Selected Media Type.

### Note

1. The Selected Transfer Syntax may be different for each message part contained in a response.

2. Implementers may use a different selection algorithm if the result is the same.

### 8.7.9 Content-Type Header Field

The Content-Type header field specifies the media type of the payload. It shall only be present when a payload is present, and any media type parameters shall specify the encoding of the corresponding message part.

In particular, a DICOM Media Type used as the value of a Content-Type header field shall have zero or one Transfer Syntax parameter (see Section 8.7.3.5.2), and zero or one charset parameter (see Section 8.7.3.5.3), which corresponds to the character encoding of the corresponding message part.

    Content-Type: dicom-media-type +transfer-syntax-mtp +charset-mtp

If there is a conflict between the Transfer Syntax specified in the media type and the one specified in the File Meta Information Transfer Syntax UID (0002,0010) Attribute, the latter has precedence.

## 8.8 Character Sets

HTTP uses charset names to indicate or negotiate the character encoding of textual content in representations [RFC6365] Section 3.3.

Character sets may be identified using the value in the IANA Preferred MIME Name column in [IANA Character Sets].

Character sets may also be identified by using the DICOM Defined Terms for the character set (see Annex D, Section C.12.1.1.2 in PS3.3 , and Section 6.1.2.3 “Encoding of Character Repertoires” in PS3.5), which shall be quoted strings since they contain the space (' ') character.

The syntax is:

    charset = token / defined-term / DQ defined-term DQ

Where

    token
| A case-insensitive charset name from the Preferred MIME Name in the IANA Character Set Registry.
    defined-term
| See Section C.12.1.1.2 “Specific Character Set” in PS3.3.

The origin server shall support the "UTF-8" charset name for RESTful Retrieve Rendered transaction but is not required to support the DICOM Defined Term "ISO_IR 192". Some DICOM Defined Terms for character sets contain space characters, and shall be enclosed in double quotes in HTTP header fields and percent encoded in URIs.

The Conformance Statement shall document all supported character sets. The Retrieve Capabilities response for all RESTful Services shall also document all supported character sets.

A request without any Character Set Query Parameter or Accept-Charset header field implies that the user agent will accept any character set in the response.

Annex D contains a mapping of some Specific Character Set (0008,0005) Defined Terms to IANA charset tokens.

### 8.8.1 Acceptable Character Sets

The term Acceptable Character Sets denotes the character sets that are acceptable to the user agent in the response. The Acceptable Character Sets are those specified in:

- the "charset" media type parameter

- the character set Query Parameter

- the Accept-Charset header field

- the default character set for the media type, if any

When Acceptable Character Sets contains a list of one or more Defined Terms they should be ordered by the user agent as specified in Section C.12.1.1.2 “Specific Character Set” in PS3.3, and Section 6.1.2.3 “Encoding of Character Repertoires” in PS3.5. This is especially important for ISO 2022 character sets.

Any charset values that are not valid or not supported shall be ignored by the origin server.

### 8.8.2 Character Set Query Parameter

See Section 8.3.3.2 .

### 8.8.3 Character Set Media Type Parameters

DICOM Media Types accept character set (charset) parameters. See Section 8.7.3.5.3.

Many other media types also accept character set (charset) parameters. See [IANA Media Types].

### 8.8.4 Accept-charset Header Field

The Accept-Charset header field has the following syntax:

    Accept-Charset = 1#(charset [weight]) / ("*" [weight])

The user agent may provide a list of Acceptable Character Sets in the Accept-Charset header field of the request. Its value is a comma-separated list of one or more charsets and/or the wildcard value ("*").

The values of the Accept-Charset header field values are prioritized by their weight parameter.

If no wildcard ("*") is present, then any character sets not explicitly mentioned in the header field are considered "not acceptable" to the client.

A request without an Accept-Charset header field implies that the user agent will accept any charset in response.

If the media type defines a "charset" parameter, it should be included with the media type in the Accept header field, rather than in the Accept-Charset header field.

If this header field has a value that is not a valid or supported character set, the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate Status Report. See Section 8.6.3.

Any Accept-Charset header field values that are not valid or not supported shall be ignored.

### 8.8.5 Selected Character Set

The origin server shall determine the Selected Character Set(s) as follows:

1. Select the first supported character set in the "charset" parameter(s) of the Selected Media Type.

2. Otherwise, select the highest priority supported charset in the character-set Query Parameter.

3. Otherwise, select the highest priority supported charset in the Accept-Charset header field.

4. Otherwise, if the Selected Media Type has a default character set that is supported, select it.

5. Otherwise, select UTF-8.

Rendered representations returned in the response shall have all contained strings returned in the Selected Character Sets.

If the character set in which the Target Resource is encoded is not the Selected CharacterSet:

- If the origin server supports transcoding all glyphs used in the Target Resource into theSelected Character Set, it shall transcode the response payload into the Selected Character Set

- Otherwise, the origin server shall return 406 (Not Acceptable).

### Note

This means that some Instances may be convertible, and others will not be, even though they have the same Specific Character Set (0008,0005).

If the user agent chooses to perform its own conversion rather than have it done by the origin server:

1. The user agent may omit the Accept-Charset header field or send the"*"wildcard

2. The user agent may transcode the character set replacing all unknown characters with a suitable replacement. For example:

   - A question mark ("?"), or other similar character indicating an unknown character.

   - The corresponding Unicode Code Point for the character, represented as "U+xxxx".

   - The four characters "\nnn", where "nnn" is the 3-digit octal representation of each byte (see Section 6.1.2.3 “Encoding of Character Repertoires” in PS3.5).

## 8.9 Retrieve Capabilities Transaction

This transaction retrieves a Capabilities Description (see Annex H), which is a machine-readable description of the service(s) implemented by an origin server. All RESTful services defined by this Part of the Standard shall implement this transaction.

The Target Resource for this transaction is an origin server. The response contains a Capabilities Description, which describes the transactions, resources, representations, etc. that are supported by the service(s).

### 8.9.1 Request

The request shall have the following syntax:

    OPTIONS SP / SP version CRLF

    Accept: 1#media-type CRLF

    *(header-field CRLF)

    CRLF

#### 8.9.1.1 Resource

The Target Resource for this transaction is the Base URI ("/") for the Service. See Section 8.2.

#### 8.9.1.2 Query Parameters

This transaction has no Query Parameters.

#### 8.9.1.3 Request Header Fields

Table 8.9.1-1. Request Header Fields

Name | Value | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | The Acceptable Media Types for the response payload
Accept-Charset | charset | O | O | The Acceptable Character Sets of the response payload

See also Section 8.4.

#### 8.9.1.4 Request Payload

The request has no payload.

### 8.9.2 Behavior

The origin server shall return a Capabilities Description, as defined in Annex H, in an Acceptable Media Type.

### 8.9.3 Response

The format of the response is as follows:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint) / (Content-Encoding: encoding) CRLF]

    *(header-field CRLF)

    CRLF

    [payload / status-report]

#### 8.9.3.1 Status Codes

Table 8.9.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 8.9.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | All Instances were successfully retrieved.
304 (Not Modified) | The user agent's current representation is up to date, so no payload was returned. This status code shall only be returned for a conditional request containing an If-None-Match header field.
Failure | 400 (Bad Request) | There was a problem with the request.

##### 8.9.3.1.1 Response Header Fields

Table 8.9.3-2. Response Header Fields

Name | Value | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | dicom-media-type | M | The media-type of the payload
Content-Length | uint | C | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 8.9.3.2 Response Payload

A success response shall have a payload containing a Capabilities Description in the Selected Media Type. The Capabilities Description shall conform to the requirements and structure defined in Annex H.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

### 8.9.4 Media Types

The media types supported by the Retrieve Capabilities service are application/vnd.sun.wadl+xml (Web Application Description Language) or application/json.

## 8.10 Notifications

### 8.10.1 Overview

Some RESTful Services support Notifications.

### 8.10.2 Conformance

An implementation shall document whether or not it supports notifications in the Conformance Statement. If the service supports notification it shall describe how WebSocket connections are opened.

### 8.10.3 Transaction Overview

Any service that supports Notifications shall support the following transactions:

Table 8.10.3-1. Notification Sub-System Transactions

Name | Method | Description
--- | --- | ---
Open Notification Connection | GET | The user agent requests that the origin server create a Notification Connection between them.
Send Event Report | N/A | The origin server sends an Event Report to an End-Point

### 8.10.4 Open Notification Connection Transaction

This transaction creates a connection between the user agent and the origin server over which the origin server can send Event Reports to the user agent.

### Note

An origin server might play the role of a user agent when communicating with another origin-server.

The connection uses the WebSocket protocol. The connection can use the same TCP port as the HTTP connection, but they are separate connections.

See [RFC6455] for details of the WebSocket protocol.

#### 8.10.4.1 Request

There is more than one way to establish a WebSocket connection. An origin server that conforms to [RFC6455] will at least support requests to open a WebSocket over an HTTP connection that have the following syntax:

    GET SP / SP version CRLF

    Host: host CRLF

    Upgrade: "WebSocket" CRLF

    Connection: "Upgrade" CRLF

    Origin: url CRLF

    Sec-WebSocket-Key: nonce CRLF

    Sec-WebSocket-Protocol: protocols CRLF

    Sec-WebSocket-Version: "13" CRLF

    *(<header-field> CRLF)

    CRLF

The origin server may support other methods of opening a WebSocket connection, which should be included in the Conformance Statement and the Retrieve Capabilities response.

##### 8.10.4.1.1 Target Resources

The Target Resource is an origin server implementing a DICOM RESTful Service.

##### 8.10.4.1.2 Query Parameters

This transaction has no query parameters.

##### 8.10.4.1.3 Request Header Fields

Table 8.10.4-1 shows the Request Header Field usage for opening a WebSocket connection over http/https.

Table 8.10.4-1. Request Header Fields

Name | Value | Usage
--- | --- | ---
Content-Type | media-type | M
Upgrade | "WebSocket" | M
Connection | "Upgrade" | M
Origin | url | M
Sec-WebSocket-Key | accept-key | M
Sec-WebSocket-Protocol | protocols | O
Sec-WebSocket-Version | version | M

For details of the request header field values and other methods of opening a WebSocket connection see [RFC6455].

##### 8.10.4.1.4 Request Payload

The request has no payload.

#### 8.10.4.2 Behavior

When the origin server receives this request, it shall open and maintain a WebSocket connection between itself and the user agent.

If the connection is lost at any point, the user agent can re-establish it by repeating this transaction.

#### 8.10.4.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    Upgrade: "WebSocket" CRLF

    Connection: "Upgrade" CRLF

    Sec-WebSocket-Accept: response-key CRLF

    Sec-WebSocket-Protocol: protocol CRLF

    *(header-field CRLF)

    CRLF

##### 8.10.4.3.1 Status Codes

Table 8.10.4-2 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 8.10.4-2. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 101 (Switching Protocols) | The protocol was successfully changed to WebSocket.
Failure | 400 (Bad Request) | There was a problem with the request.

##### 8.10.4.3.2 Response Header Fields

Table 8.10.4-3. Response Header Fields

Name | Value | Origin Server Usage | Description
--- | --- | --- | ---
Upgrade | "WebSocket" | M |
Connection | "Upgrade" | M |
Origin | url | M |
Sec-WebSocket-Accept | response-key | M | See [RFC6455]
Sec-WebSocket-Protocol | protocol | M | See [RFC6455]

See also Section 8.4.

##### 8.10.4.3.3 Response Payload

The response has no payload.

### 8.10.5 Send Event Report Transaction

The origin server uses this transaction to notify a user agent of Events.

This transaction sends a notification, containing an Event Report, over an established Notification Connection from an origin server to a user agent. Unlike most transactions, this transaction is initiated by the origin server.

This transaction corresponds to a DIMSE N-EVENT-REPORT action.

Each service may define Events, and the corresponding Event Report messages and their contents, related to its resources.

#### 8.10.5.1 Request

The request shall use the WebSocket Data Frame transmission protocol.

##### 8.10.5.1.1 Request Payload

The data frames shall have an opcode of "%x1" (text).

The data frame payload data shall be a DICOM JSON Dataset containing the Attributes of the Event Report.

### Note

1. The WebSocket protocol does not currently allow content negotiation so it is not possible to support both XML and JSON encoding of Event Report messages.

2. If the Event Reports are being proxied into DIMSE N-EVENT Reports, a Message ID (0000,0110) must be managed by the proxy.

#### 8.10.5.2 Behavior

The user agent shall accept all Attributes included in any Event Report. No requirements are placed on what the user agent does with this information.

#### 8.10.5.3 Response

None.

## 8.11 Security and Privacy

It is very likely that DICOM objects contain Protected Health Information. Privacy regulations in the United States (HIPAA), Europe (GDPR), and elsewhere, require that Individually Identifiable Information be kept private. It is the responsibility of implementers of the DICOM Standard to ensure that governmental regulations for security and privacy are satisfied.

See, for example, [ONC Privacy Security Guide].

# 9 URI Service

## 9.1 Overview

The URI Service, also known as WADO-URI, enables a user agent to retrieve representations of Instances using HTTP.

### 9.1.1 Resource Descriptions

The URI Service does not define resources in the form of a Target Resource Path, such as {/resource}. The Target URI of each transaction is a reference to the Base URI ("/") and the Target Resource is identified using query parameter values. The resources for the URI Service are instances of Composite Storage SOP Classes defined in PS3.4.

### 9.1.2 Common Query Parameters

The Query Parameters specified in this Section may be used with either the Retrieve DICOM Instance or Retrieve Rendered Instance transactions, and are applicable to all supported SOP Classes.

#### 9.1.2.1 Mandatory Query Parameters

The origin server shall support Query Parameters as required in Table 9.1.2-1.

The user agent shall supply in the request Query Parameters as required in Table 9.1.2-1.

The Query Parameters may appear in any order.

Table 9.1.2-1. Mandatory Query Parameters

Name | Values | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
requestType | "WADO" | M | M | Section 9.1.2.1.1
studyUID | uid | M | M | Section 9.1.2.1.3
seriesUID | uid | M | M | Section 9.1.2.1.3
objectUID | uid | M | M | Section 9.1.2.1.4

See Section 8.3.

### Note

To identify a SOP Instance, only a SOP Instance UID is required, because any UID is globally unique. However, the Standard requires that the UIDs of the higher levels in the DICOM Information Model (i.e., series and study) are specified, in order to support the use of DICOM devices that support only the baseline hierarchical (rather than extended relational) Query/Retrieve model, which requires the Study Instance UID and Series Instance UID to be defined when retrieving an Instance, as defined in PS3.4.

##### 9.1.2.1.1 Request Type

    requestType = %s"requestType=" token

    token       = "WADO"

This parameter specifies that this is a URI service request. The parameter name shall be "requestType", and the value shall be "WADO".

If the value is other than "WADO", and the origin server does not support the value, the response shall be 400 (Bad Request), and may include a payload containing an appropriate error message.

##### 9.1.2.1.2 Study UID

    study = %s"studyUID=" uid

The value of this parameter is a Study Instance UID.

##### 9.1.2.1.3 Series UID

    series = %s"seriesUID=" uid

The value of this parameter is a Series Instance UID.

##### 9.1.2.1.4 Instance UID

    instance = %s"objectUID=" uid

The value of this parameter is a SOP Instance UID.

#### 9.1.2.2 Optional Query Parameters

The parameters defined in this section are optional for all URI requests.

Table 9.1.2-2. Optional Query Parameters

Key | Values | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
contentType | media-type | O | O | Section 8.3.3.1
charset | token | O | O | Section 8.3.3.2

See Section 8.3.

##### 9.1.2.2.1 Acceptable Media Types

The Accept Query Parameter specifies the Acceptable Media Types for the response payload. See Section 8.7.5. The case-sensitive name of the parameter is "contentType". Its syntax is:

    accept = %s"contentType=" dicom / 1#rendered-media-type

The value of this parameter, if present, shall be either application/dicom, or one or more of the Rendered Media Types.

The DICOM Media Type transfer-syntax and character set parameters are forbidden in the request. If either are present, the response shall be 400 (Bad Request), and may include a payload containing an appropriate error message.

See Section 8.7.5 for other errors related to this parameter.

### Note

URI origin servers may support Transfer Syntax and charset Query Parameters. This is different from the approach used by the DICOM RESTful services, which uses transfer-syntax and charset media type parameters.

##### 9.1.2.2.2 Acceptable Character Sets

    charset-qp = %s"charset=" 1#(charset [weight])

The value of this parameter is a comma-separated list of one or more character-set identifiers. See Section 8.8.1.

### 9.1.3 Common Media Types

The origin server shall support the application/dicom media type as described in Section 8.7.3.1 and Rendered Media Types as described in Section 8.7.4.

Support for the Transfer Syntax and Character Set media type parameters is forbidden for URI Services.

## 9.2 Conformance

An implementation conforming to the URI service shall support retrieval of one or more of the Information Objects specified for the Storage Service Class, as specified in Section B.5 in PS3.4 .

An implementation's Conformance Statement shall document the Information Objects supported for the URI service, and whether it plays the role of origin server or user agent, or both.

## 9.3 Transactions Overview

The URI Service has two transactions:

Retrieve DICOM Instance

  This transaction retrieves a single Instance in the application/dicom media type.

Retrieve Rendered Instance

  This transaction retrieves a single Instance in a Rendered Media Type.

These two transactions have the same "requestType" type but are differentiated by their Selected Media Type.

If there is no "contentType" Query Parameter and the Accept header field is '*/*', then the Selected Media Type defaults to 'image/jpeg' media type and the transaction defaults to Retrieve Rendered Instance.

## 9.4 Retrieve DICOM Instance Transaction

This transaction retrieves a single Instance in the application/dicom media type. See Section 8.7.3.

### 9.4.1 Request

The request shall have the following syntax:

    GET SP / ?{requestType}&{study}&{series}&{instance}

             {&accept}

             {&charset}

             {&anonymize}

             {&transferSyntax}

             SP HTTP/1.1 CRLF

    Accept: uri-media-type CRLF

    *(header-field CRLF)

    CRLF

#### 9.4.1.1 Target Resource

The Target Resource shall be an Instance of a Composite Storage SOP class defined in PS3.4.

#### 9.4.1.2 Query Parameters

The origin server shall support Query Parameters as required in Table 9.4.1-1 .

The user agent shall supply in the request Query Parameters as required in Table 9.4.1-1 .

Table 9.4.1-1. Optional Query Parameters

Key | Values | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
anonymize | "yes" | O | O | Section 9.4.1.2.1
annotation | "patient" "technique" | O | O | Section 9.4.1.2.2
transferSyntax | uid | O | O | Section 9.4.1.2.3

##### 9.4.1.2.1 Anonymize

    anonymize = %s"anonymize=" token

    token = "yes"

This parameter specifies that the returned representations shall have all Individually Identifiable Information (III) removed, as defined in Annex E “Attribute Confidentiality Profiles” in PS3.15 Basic Profile with Clean Pixel Data Option. Its name is "anonymize" and its value is a token. The defined token is "yes". If this parameter is not present, no anonymization is requested.

##### 9.4.1.2.2 Annotation

    annotation = 1#( %s"patient" / %s"technique" )

This parameter specifies that the rendered images shall be annotated with patient and/or procedure information. Its value is a comma-separated list of one or more keywords.

Where

    "patient"
| indicates that the rendered images shall be annotated with patient information (e.g., patient name, birth date, etc.).
    "technique"
| indicates that the rendered images shall be annotated with information about the procedure that was performed (e.g., image number, study date, image position, etc.).

The origin server may support additional keywords, which should be included in the Conformance Statement and the Retrieve Capabilities response.

##### 9.4.1.2.3 Transfer Syntax

    transfer-syntax = %s"transferSyntax" "=" transfer-syntax-uid

This parameter specifies a Transfer Syntax UID. Its name is "transferSyntax" and its value is a single Transfer Syntax UID. It is optional for both the user agent and origin server. See Section 8.7.3.5 for details.

#### 9.4.1.3 Request Header Fields

The origin server shall support header fields as required in Table 9.4.1-2 in the request.

The user agent shall supply in the request header fields as required in Table 9.4.1-2.

Table 9.4.1-2. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | O | M | The Acceptable Media Types for the response payload
Accept-Charset | charset | O | M | The Acceptable Character Sets of the response payload

See also Section 8.4.

#### 9.4.1.4 Request Payload

The request has no payload.

### 9.4.2 Behavior

A success response shall contain the Target Resource in an Acceptable DICOM Media Type. See Section 8.7.5.

#### 9.4.2.1 Request Type

If the Query Parameter is not present; or if it is present with a value other than "WADO" and the origin server does not support the value, then the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

#### 9.4.2.2 Study, Series, and Instance UIDs

If the Study, Series, or Instance UID Query Parameters are not present, the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

#### 9.4.2.3 Anonymize

If the Query Parameter is supported and present, and if any of the following are true:

- the number of parameter values is not equal to one, or

- the parameter value is not "yes"

then the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

If the Target Resource has not already been de-identified, the returned Instance shall have a new SOP Instance UID.

If the origin server is either unable or refuses to anonymize the Target Resource, it may return an error response.

#### 9.4.2.4 Transfer Syntax UID

If this Query Parameter is supported and present with a value that is a valid Transfer Syntax UID, the response payload shall be encoded in the specified Transfer Syntax.

If it is not present, the response payload shall be encoded in the default Transfer Syntax for DICOM Web Services, which is Explicit VR Little Endian Uncompressed.

If the Query Parameter is supported and present, and if any of the following are true:

- the number of parameter values is not equal to one, or

- the parameter value is not a valid UID

then the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

If the parameter value is a valid Transfer Syntax UID, but is not supported by the origin server, the response shall be 406 (Not Acceptable), and may include a payload containing a list of the Transfer Syntaxes supported by the origin server.

### Note

The origin server may not be able to convert all Instances to all the Transfer Syntaxes it supports.

### 9.4.3 Response

    version SP status-code SP reason-phrase

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    Content-Location: url CRLF

    *(header-field CRLF)

    CRLF

    [payload / status-report]

#### 9.4.3.1 Status Codes

Table 9.4.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 9.4.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The Instance was successfully retrieved.
Failure | 400 (Bad Request) | There was a problem with the request.
404 (Not Found) | The resource corresponding to the UIDs in the Query Parameters was not found.
410 (Gone) | The resource corresponding to the UIDs in the Query Parameters, once existed, but no longer exists.

#### 9.4.3.2 Response Header Fields

The origin server shall support header fields as required in Table 9.4.3-2.

Table 9.4.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | dicom-media-type | M | The media-type of the payload
Content-Length | uint | M | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | M | Shall be present if a content encoding has been applied to the payload

See Section 8.4.

#### 9.4.3.3 Response Payload

A successful response shall have a payload containing the Target Resource in the application/dicom media type.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 9.5 Retrieve Rendered Instance Transaction

This transaction returns a single Instance in a Rendered Media Type. See Section 8.7.4.

The Acceptable Media Type shall not be application/dicom. If it is, the response should be 406 (Not Acceptable) response.

### 9.5.1 Request

The request shall have the following syntax:

    GET SP /?{requestType}&{study}&{series}&{instance}{&frameNumber}

             {&accept}

             {&charset}

             {&annotation}

             {&rows}

             {&columns}

             {&region}

             {&windowCenter}

             {&windowWidth}

             {&imageQuality}

             {&annotation}

             {&presentationSeriesUID}

             {&presentationUID}

    SP HTTP/1.1 CRLF

    Accept: 1#media-type CRLF

    *(header-field CRLF)

    CRLF

#### 9.5.1.1 Target Resource

The Target Resource shall be an Instance of a Composite SOP Class as defined in PS3.3.

#### 9.5.1.2 Query Parameters

The Query Parameters in this section shall only be included in a request if the DICOM Category of the Target Resource is Single Frame, Multi-Frame, or Video as defined in Section 8.7.2.

The origin server shall support Query Parameters as required in Table 9.5.1-1.

The user agent shall supply in the request Query Parameters as required in Table 9.5.1-1.

Table 9.5.1-1. Query Parameters

Key | Values | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
contentType | rendered-media-type | O | M | Section 9.1.2.2.1
charset | charset | O | M | Section 9.1.2.2.2
frameNumber | uint | O | O | Section 9.5.1.2.1
imageAnnotation | "patient" / "technique" | O | O | Section 9.5.1.2.2
imageQuality | uint | O | O | Section 9.5.1.2.3
rows | uint | O | O | Section 9.5.1.2.4.1
columns | uint | O | O | Section 9.5.1.2.4.2
region | 4decimal | O | O | Section 9.5.1.2.5
windowCenter | decimal | O | O | Section 9.5.1.2.6.1
windowWidth | decimal | O | O | Section 9.5.1.2.6.2
presentationSeriesUID | uid | O | O | Section 9.5.1.2.7.1
presentationUID | uid | O | O | Section 9.5.1.2.7.2

##### 9.5.1.2.1 Frame Number

    frame-number = %s"frameNumber" "=" uint

This parameter specifies a single frame within a multi-frame image Instance, as defined in PS3.3 that shall be returned. Its name is "frameNumber" and its value shall be a positive integer (i.e., starts at 1 not 0).

##### 9.5.1.2.2 Image Annotation

See Section 8.3.5.1.1.

##### 9.5.1.2.3 Image Quality

See Section 8.3.5.1.2.

##### 9.5.1.2.4 Viewport

The Viewport Query Parameters specify the dimensions of the user agent's viewport. The Viewport Rows and Columns parameters specify the height and width, in pixels, of the returned image. If either parameter is present, both shall be present.

The Viewport parameters syntax in this Section overrides that described in Section 8.3.5.1.3; however, the scaling behavior described in that section still applies.

###### 9.5.1.2.4.1 Viewport Rows

    rows = %s"rows" "=" uint

This parameter specifies the number of pixel rows in the returned image. It corresponds to the height in pixels of the user agent's viewport. Its name is "rows" and its value shall be a positive integer.

###### 9.5.1.2.4.2 Viewport Columns

    columns = %s"columns" "=" uint

This parameter specifies the number of pixel columns in the returned image. It corresponds to the width, in pixels, of the user agent's viewport. Its name is "columns" and its value shall be a positive integer.

##### 9.5.1.2.5 Source Image Region

    region = %s"region" "=" xmin "," ymin "," xmax "," ymax

    xmin = decimal

    ymin = decimal

    xmax = decimal

    ymax = decimal

This parameter specifies a rectangular region of the Target Resource. Its name is "region" and its values shall be a comma-separated list of four positive decimal numbers:

xmin

  the left column of the region

ymin

  the top row of the region

xmax

  the right column of the region

ymax

  the bottom row of the region

The region is specified using a normalized coordinate system relative to the size of the original image matrix, measured in rows and columns. Where

- 0.0, 0.0 corresponds to the top row and left column of the image

- 1.0, 1.0 corresponds to the bottom row and right column of the image

and

- 0.0 <= xmin < xmax <= 1.0

- 0.0 <= ymin < ymax <= 1.0

This parameter when used in conjunction with one of the viewport parameters, allows the user agent to map a selected area of the source image into its viewport.

##### 9.5.1.2.6 Windowing

The Windowing parameters (Window Center and Window Width) are optional; however, if either is present, both shall be present. If only one is present the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

The URI Service does not support the "function" Query Parameter, which is described in Section 8.3.5.1.4.

The Windowing and Presentation State parameters shall not be present in the same request. If both are present the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

The Windowing parameters shall not be present if contentType is application/dicom; if either is present the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

###### 9.5.1.2.6.1 Window Center

    window-center = %s"windowCenter" "=" decimal

This parameter specifies the Window Center of the returned image as defined in PS3.3. Its name is "windowCenter" and its value shall be a decimal number.

###### 9.5.1.2.6.2 Window Width

    window-width = %s"windowWidth" "=" decimal

This parameter specifies the Window Width of the returned image as defined in PS3.3. Its name is "windowWidth" and its value shall be a decimal number.

##### 9.5.1.2.7 Presentation State

The parameters below specify the Series and SOP Instance UIDs of a Presentation State. They are optional. However, if one is present, they shall both be present.

If the Presentation State parameters are present, then the only other optional parameters that may be present are Annotation, Image Quality, Region, and Viewport.

###### 9.5.1.2.7.1 Presentation Series UID

    presentation-series = %s"presentationSeriesUID" "=" uid

This parameter specifies the Series containing the Presentation State Instance to be used to render the image. Its name shall be "presentationSeriesUID" and its value shall be a Series Instance UID.

###### 9.5.1.2.7.2 Presentation UID

    presentation-instance = %s"presentationUID" "=" uid

This parameter identifies the Presentation State Instance, which is used to render the image. Its name is "presentationUID" and its value shall be a Presentation State Instance UID of a Presentation State Instance.

#### 9.5.1.3 Request Header Fields

The origin server shall support header fields as required in Table 9.5.1-2.

The user agent shall supply in the request header fields as required in Table 9.5.1-2.

Table 9.5.1-2. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | The Acceptable Media Types for the response payload
Accept-Charset | charset | O | M | List of one or more character sets

The Acceptable Media Types shall contain only Rendered Media Types. See Section 8.7.4.

#### 9.5.1.4 Request Payload

The request message has no payload.

### 9.5.2 Behavior

A success response shall contain the Target Resource in an Acceptable Rendered Media Type. See Section 8.7.4.

The Target Resource shall be rendered and returned as specified in the Query Parameters. Presentation State transformations are applied using the appropriate rendering pipeline specified in Section N.2 “Pixel Transformation Sequence” in PS3.4. Any Source Image Region parameters are applied after any Presentation State parameters. Any Viewport parameters are applied after any Source Image Region.

Even if the output of the image is defined in P-Values (grayscale values intended for display on a device calibrated to the DICOM Grayscale Standard Display Function PS3.14), or contains an ICC profile, the grayscale or color space for the rendered image is not defined by this Standard.

#### 9.5.2.1 Frame Number

If this Query Parameter is supported and is present in the request,the origin server shall use the specified frame as the Target Resource.

However, if any of the following are true:

- the Target Resource is not a multi-frame image or video,

- the number of parameter values is not equal to one, or

- the parameter value is not a positive integer less than or equal to the number of frames in the Instance

the origin server shall return a 400 (Bad Request) responseand may include a payload containing an appropriate error message.

#### 9.5.2.2 Windowing

If these Query Parameters are supported and are present in the request, the origin server shall use them as described in Section 8.3.5.1.4.

However, if any of the following are true:

- only one of the parameters is present,

- either of the parameter values is not a decimal number, or

- the Presentation Series UID or the Presentation UID Query Parameters are present

then the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

#### 9.5.2.3 Presentation State

If the Target Resource is a Presentation State and If the Presentation Size Mode is SCALE TO FIT or TRUE SIZE, then the displayed area specified in the Presentation State shall be scaled, maintaining the aspect ratio, to fit the size specified by the rows and columns parameters if present, otherwise the displayed area selected in the presentation state will be returned without scaling.

### Note

1. The intent of the TRUE SIZE mode in the presentation state cannot be satisfied, since the physical size of the pixels displayed by the web browser is unlikely to be known. If the Presentation Size Mode in the presentation state is MAGNIFY, then the displayed area specified in the presentation shall be magnified (scaled) as specified in the presentation state. It will then be cropped to fit the size specified by the viewport parameters, if present.

2. Any Displayed Area relative annotations specified in the presentation state are rendered relative to the Specified Displayed Area within the presentation state, not the size of the returned image.

Though the output of the presentation state is defined in DICOM to be in P-Values (grayscale values intended for display on a device calibrated to the DICOM Grayscale Standard Display Function PS3.14), the grayscale or color space for the images returned by the request is not defined by this standard.

However, if any of the following are true:

- the Frame Number, Source Image Region, or Windowing parameters are present,

- the Presentation Series UID does not correspond to an existing Presentation Series on the origin server, or

- the Presentation UID does not correspond to an existing Presentation Instance on the origin server

the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

#### 9.5.2.4 Source Image Region

If this Query Parameter is supported and present:

- An image matrix corresponding to the region specified by Source Image Region shall be returned with its size corresponding to the specified normalized coordinate values.

- If the Presentation UID parameter is present, the region shall be selected after the corresponding presentation state has been applied on the images.

However, if any of the following are true:

- the Query Parameter specifies an ill-defined region,

- there are greater or fewer than four parameter values present, or

- any of the parameters do not conform to the requirements specified in Section 9.5.1.2.5

the origin server shall return a 400 (Bad Request) response and may include a payload containing an appropriate error message.

#### 9.5.2.5 Viewport

Viewport parameters are applied to the region specified by the Presentation State and/or Source Image Region, if present; otherwise, the Viewport Query Parameters are applied to the full original image.

If both rows and columns Query Parameters are specified, then each shall be interpreted as a maximum, and a size will be chosen for the returned image within these constraints, maintaining the aspect ratio of the selected region.

If the rows Query Parameter is absent and the columns Query Parameter is present, the number of rows in the returned image shall be chosen to maintain the aspect ratio of the selected region.

If the columns Query Parameter is absent and the rows Query Parameter is present, the number of columns in the returned image shall be chosen to maintain the aspect ratio of the selected region.

If both Query Parameters are absent, the image (or selected region) is returned with its original size (or the size of the presentation state applied to the image), resulting in one pixel in the returned image for each pixel in the original image.

### 9.5.3 Response

    version SP status-code SP reason-phrase

    [Content-Type: rendered-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [payload / status-report]

#### 9.5.3.1 Status Codes

Table 9.5.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 9.5.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | All Instances were successfully rendered and retrieved.
Failure | 400 (Bad Request) | There was a problem with the request.

#### 9.5.3.2 Response Header Fields

The origin server shall support header fields as required in Table 9.5.3-2.

Table 9.5.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | Shall be present if the response contains a payload. See Section 8.4.3.
Content-Encoding | encoding | C | Shall be present if the response payload has a content encoding. See Section 8.4.3.
Content-Length | uint | C | Shall be present if the response payload does not have a content encoding. See Section 8.4.3.
Content-Location | url | C | Shall be present if the response has a payload containing a resource. See Section 8.4.3.

See also Section 8.4.

#### 9.5.3.3 Response Payload

A success response shall contain a single rendered image encoded in the Selected Media Type.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

# 10 Studies Service and Resources

## 10.1 Overview

The Studies Resource enables a user agent to store, retrieve, update, and search an origin server for DICOM Studies, Series, and Instances, along with their /metadata, /rendered, and /thumbnail variants; as well as Frames and Bulkdata.

The Retrieve transaction of this Service is also known as WADO-RS. The Store transaction of this Service is also known as STOW-RS. The Search transaction of this Service is also known as QIDO-RS. See Section 10.3.

### 10.1.1 Resource Descriptions

The Studies Service manages a collection of DICOM Study resources. Each Study is organized in a hierarchy of sub-resources that correspond to the DICOM Information Model. See Section 7 “DICOM Model of the Real World” in PS3.3.

There are three top level resources:

/studies | references all Studies managed by the service.
/series | references all Series managed by the service.
/instances | references all Instances managed by the service.

The following URI Template variables are used in resource definitions in this Section.

{study} | the Study Instance UID of a Study managed by the Studies Service.
{series} | the Series Instance UID of a Series contained within a Study resource.
{instance} | the SOP Instance UID of an Instance contained within a Series resource.
{frames} | a comma-separated list of frame numbers, in ascending order, contained within an Instance.
{/bulkdata} | an opaque URI that references a Bulkdata Value.

The Studies Service defines the following resources:

Table 10.1-1. Resources and Descriptions

Resource | Description
--- | ---
Studies Service | The Base URI of the Studies Service.
All Studies | The All Studies resource references the entire collection of Studies contained in the Studies Service.
Study | The Study resource references a single Study.
Study Metadata | The Study Metadata resource references the Metadata of a single Study.
Rendered Study | The Rendered Study resource references a Study to be rendered.
Study Thumbnail | The Study Thumbnail resource references a thumbnail image of a Study.
Study's Series | The Study's Series resource references the collection of all Series contained in a Study.
Study's Instances | The Study's Instances resource references the collection of all Instances in a single Study.
All Series | The All Series resource references the collection of all Series in all Studies contained in the Studies Service.
Series | The Series resource references a single Series.
Series Metadata | The Series Metadata resource contains the Metadata of a single Series in a Study.
Rendered Series | The Rendered Series resource references a Series to be rendered.
Series Thumbnail | The Series Thumbnail resource references a thumbnail image of a Series.
Series' Instances | The Series' Instances resource references the collection of all Instances in a single Series.
All Instances | The All Instances resource references the collection of all Instances in all Series in all Studies contained in the Studies Service.
Instance | The Instance resource references a single Instance.
Instance Metadata | The Instance Metadata resource contains the Metadata of a single Instance.
Rendered Instance | The Rendered Instance resource references an Instance to be rendered.
Instance Thumbnail | The Instance Thumbnail resource references a thumbnail image of an Instance.
Frames | The Frames resource references an ordered collection of frames in a single multi-frame Instance.
Rendered Frames | The Rendered Frames resource references an ordered collection of frames of a single multi-frame Instance, to be rendered.
Frame Thumbnail | The Frame Thumbnail resource references a thumbnail image for frames within an Instance.
Bulkdata | The Bulkdata resource contains one or more Bulkdata Values.

### 10.1.2 Common Query Parameters

The origin server shall support Query Parameters as required in Table 10.1.2-1.

The user agent shall supply in the request Query Parameters as required in Table 10.1.2-1.

Table 10.1.2-1. Common Query Parameters

Name | Value | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | O | M | Section 8.3.3.1
Accept-Charset | charset | O | M | Section 8.3.3.2

### 10.1.3 Common Media Types

The origin server media type requirements are defined in each Transaction of this Service.

## 10.2 Conformance

An origin server claiming conformance to the Retrieve Transaction of the Studies Service:

- shall support the Retrieve Capabilities Transaction (see Section 8.9.1);

- shall support the Retrieve Transaction for all mandatory resources in Table 10.3-2.

An origin server claiming conformance to the Store Transaction of the Studies Service:

- shall support the Retrieve Capabilities Transaction (see Section 8.9.1);

- shall support the Store Transaction for all mandatory resources in Table 10.3-2.

An origin server claiming conformance to the Search Transaction of the Studies Service:

- shall support the Retrieve Capabilities Transaction (see Section 8.9.1);

- shall support the Search Transaction for all mandatory resources in Table 10.3-2.

The user agent may support any of the transactions for any of the corresponding resources in Table 10.3-2.

## 10.3 Transactions Overview

The Studies Service consists of the following transactions:

Table 10.3-1. Studies Service Transactions

Transaction Name | Method | Payload | Description
--- | --- | --- | ---
Request | Success Response
Retrieve | GET | N/A | Instance(s) or Bulkdata | Retrieve one or more representations of DICOM Resources.
Store | POST | Instance(s) | Store Instances Response Module | Stores one or more representations of DICOM Resources, contained in the request payload, in the location referenced by the Target Resource.
Search | GET | N/A | Result(s) | Searches the Target Resource for DICOM objects that match the search parameters and returns a list of matches in an Acceptable Media Type.

In Table 10.3-2, the Target Resources permitted for each transaction are marked with M if support is mandatory for the origin server and O if it is optional. A blank cell indicates that the resource is not allowed in the transaction.

Table 10.3-2. Resources by Transaction

Resource | Retrieve | Store | Search
--- | --- | --- | ---
Studies Service |  |  |
All Studies |  | M | M
Study | M | M | M
Study Metadata | M |  |
Study Bulkdata | M |  |
Rendered Study | M |  |
Study Thumbnail | O |  |
Study's Series |  |  | M
Study's Instances |  |  | M
All Series |  |  | M
Series | M |  | M
Series Metadata | M |  |
Series Bulkdata | M |  |
Series' Instances |  |  | M
Rendered Series | M |  |
Series Thumbnail | O |  |
All Instances |  |  | M
Instance | M |  | M
Instance Metadata | M |  |
Instance Bulkdata | M |  |
Rendered Instance | M |  |
Instance Thumbnail | O |  |
Frames | M |  |
Rendered Frames | M |  |
Frame Thumbnail | O |  |
Bulkdata | M | M |

## 10.4 Retrieve Transaction

This Transaction uses the GET method to retrieve the Target Resource. The media type in the response payload will depend on the Target URI and the Query Parameters; for example, Instances as application/dicom, Metadata as application/dicom+json or rendered Instances as application/jpeg images.

The retrieve transaction supports DICOM, Rendered, and Thumbnail Resources.

### 10.4.1 Request

The request shall have the following syntax:

    GET SP "/" {/resource} {?parameter*} SP versionCRLF

    Accept: 1#media-type CRLF

    *(header-fieldCRLF)

    CRLF

Where parameter is one of the Query Parameters defined for the Target Resource in Section 10.4.1.2.

#### 10.4.1.1 Target Resources

##### 10.4.1.1.1 DICOM Resources

Table 10.4.1-1 defines the DICOM resources that may be retrieved.

Table 10.4.1-1. Retrieve Transaction DICOM Resources

Resource | URI Template
--- | ---
Study |
    /studies/{study}
Series |
    /studies/{study}/series/{series}
Instance |
    /studies/{study}/series/{series}/instances/{instance}
Frames |
    /studies/{study}/series/{series}/instances/{instance}/frames/{frames}
Bulkdata |
    /{/bulkdata}

##### 10.4.1.1.2 Metadata Resources

Table 10.4.1-2 defines the resources used to retrieve the metadata contained in Instances.

Table 10.4.1-2. Retrieve Transaction Metadata Resources

Resource | URI Template
--- | ---
Study Metadata |
    /studies/{study}/metadata
Series Metadata |
    /studies/{study}/series/{series}/metadata
Instance Metadata |
    /studies/{study}/series/{series}/instances/{instance}/metadata

The Metadata Resources are used to retrieve the DICOM instances without retrieving Bulkdata. The Metadata returned for a study, series, or instance resource includes all Attributes in the resource. For Data Elements having a Value Representation (VR) of DS, FL, FD, IS, LT, OB, OD, OF, OL, OW, SL, SS, ST, UC, UL, UN, US, and UT, the origin server is permitted to replace the Value Field of the Data Element with a Bulkdata URI. The user agent can use the Bulkdata URI to retrieve the Bulkdata.

##### 10.4.1.1.3 Rendered Resources

A Retrieve Transaction on a Rendered Resource will return a response that contains representations of a DICOM Resource rendered as appropriate images, videos, text documents, or other representations. Its primary use case is to provide user agents with a simple means to display medical images and related documents, without requiring deep knowledge of DICOM data structures and encodings.

A Rendered Resource contains one or more rendered representations, i.e., in a Rendered Media type, of its parent DICOM Resource. Table 10.4.1-3 shows the Rendered Resources supported by the Retrieve transaction along with their associated URI templates.

Table 10.4.1-3. Retrieve Transaction Rendered Resources

Resource | URI Template
--- | ---
Rendered Study |
    /studies/{study}/rendered
Rendered Series |
    /studies/{study}/series/{series}/rendered
Rendered Instance |
    /studies/{study}/series/{series}/instances/{instance}/rendered
Rendered Frames |
    /studies/{study}/series/{series}/instances/{instance}/frames/{frames}/rendered

The origin server shall be able to render all valid Instances of the Composite SOP classes for which conformance is claimed, e.g., origin server shall be able to render all Photometric Interpretations that are defined in the IOD for that SOP class.

The content type of the response payload shall be a Rendered Media Type. See Section 8.7.4.

##### 10.4.1.1.4 Thumbnail Resources

A Retrieve Transaction on a Thumbnail resource will return a response that contains a rendered representation of its parent DICOM Resource.

Table 10.4.1-4 shows the Thumbnail resources supported by the Retrieve transaction along with their associated URI templates.

Table 10.4.1-4. Retrieve Transaction Thumbnail Resources

Resource | URI Template
--- | ---
Study Thumbnail |
    /studies/{study}/thumbnail
Series Thumbnail |
    /studies/{study}/series/{series}/thumbnail
Instance Thumbnail |
    /studies/{study}/series/{series}/instances/{instance}/thumbnail
Frame Thumbnail |
    /studies/{study}/series/{series}/instances/{instance}/frames/{frames}/thumbnail

The representation returned in the response to a Retrieve Thumbnail resource request shall be in a Rendered Media Type. The Thumbnail shall not contain any Patient Identifying Information. Only a single image shall be returned.

If the origin server supports any of the Thumbnail resources, it shall support all of them.

The origin server will determine what constitutes a meaningful representation.

The origin server may return a redirection response (HTTP status code 302) to a rendered resource instead of returning a rendered image.

There is no requirement that Thumbnail resources be related to any Icon Image Sequence (0088,0200) encoded in Instances or returned in query responses.

#### 10.4.1.2 Query Parameters

The origin server shall support Query Parameters as required in Table 10.4.1-5.

The user agent shall supply in the request Query Parameters as required in Table 10.4.1-5.

Table 10.4.1-5. Query Parameters by Resource

Key | Resource Category | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
accept | All | O | M | Section 8.3.3.1
charset | Text | O | M | Section 8.3.3.2
annotation | Rendered | O | M | Section 8.3.5.1.1
quality | Rendered | O | M | Section 8.3.5.1.2
viewport | Rendered | O | M | Section 8.3.5.1.3
Thumbnail | O | O
window | Rendered | O | M | Section 8.3.5.1.4
iccprofile | Rendered | O | O | Section 8.3.5.1.5

#### 10.4.1.3 Request Header Fields

The origin server shall support header fields as required in Table 10.4.1-6 in the request.

The user agent shall supply in the request header fields as required in Table 10.4.1-6.

Table 10.4.1-6. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | The Acceptable Media Types of the response payload
Accept-Charset | charset | O | M | The Acceptable Character Sets of the response payload

See also Section 8.4.

#### 10.4.1.4 Request Payload

The request shall have no payload.

### 10.4.2 Behavior

A success response shall contain the Target Resource in an Acceptable Media Type. See Section 8.7.4.

### 10.4.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    payload / status-report

#### 10.4.3.1 Status Codes

Table 10.4.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 10.4.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The response payload contains representations for all of the Target Resource(s)
206 (Partial Content) | The response payload contains representations for some, but not all, of the Target Resource(s)
Failure | 400 (Bad Request) | The origin cannot process the request because of errors in the request headers or parameters.
404 (Not Found) | The Target Resource does not exist
406 (Not Acceptable) | The origin server does not support any of the Acceptable Media Types
410 (Gone) | The Target Resource has been deleted
413 (Payload Too Large) | The Target Resource is too large to be returned by the origin server.

#### 10.4.3.2 Response Header Fields

The origin server shall supply header fields as required by Table 10.4.3-2.

Table 10.4.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | The media type of the payload. Shall be present if the response has a payload.

See also Section 8.4.

#### 10.4.3.3 Response Payload

A success response shall have a payload containing one or more representations of the Target Resource in an Acceptable Media Type. The payload may be single part or multipart depending on the media type.

A failure response payload should contain a Status Report describing any failures, warnings, or other useful information.

Table 10.4.3-3 shows the media type category for each resource type. The origin server shall support the default and required media types in the media type category specified.

Table 10.4.3-3. Resource Media Types

Resource | Section | Media Type Category
--- | --- | ---
DICOM Resources | Section 10.4.1.1.1 | DICOM Media Types
Metadata Resources | Section 10.4.1.1.2 | DICOM Media Types
Rendered Resources | Section 10.4.1.1.3 | Rendered Media Types
Thumbnail Resources | Section 10.4.1.1.4 | Rendered Media Types

DICOM Media Types are described in Section 8.7.3. Rendered Media Types are described in Section 8.7.4.

### 10.4.4 Media Types

The origin server shall support the media types specified as default or required in Table 10.4.4-1.

Table 10.4.4-1. Default, Required, and Optional Media Types

Media Type | Usage | Section
--- | --- | ---
application/dicom | Required | Section 8.7.3.1
application/dicom+json | Default | Section 8.7.3.2
multipart/related; type="application/dicom+xml" | Required | Section 8.7.3.2
Rendered Media Types | Optional | Section 8.7.4

The origin server shall support the Transfer Syntax and Character Set media type parameters. See Section 8.7.3.5.2 and Section 8.7.3.5.3.

### 10.4.5 Conformance Statement

The creator of an implementation shall document in its Conformance Statement:

- the origin server and/or user agent role(s) played,

- the resources supported for this transaction,

- the media types supported for this transaction,

- the optional Query Parameters supported,

- the optional Header Fields supported.

The creator of an implementation shall also document:

- The Composite SOP classes supported, including:

  - the Image Storage SOP classes supported,

  - the Image Storage SOP classes supported by Rendered Presentation States.

- If Thumbnails are supported:

  - A high-level description of the method used to render thumbnails for the study, series, or instance.

    ### Note

    The description could indicate, for example, whether a representative instance is chosen from a series, and how that instance is selected, or that per-modality fixed content is used.

  - The minimum and maximum sizes for thumbnails.

  - Character sets supported for Thumbnail resources (if other than UTF-8).

## 10.5 Store Transaction

This transaction uses the POST method to Store representations of Studies, Series, and Instances contained in the request payload.

The Store transaction supports only DICOM resources. The resource can be supplied as a single Instance, or as separate Metadata and Bulkdata.

### 10.5.1 Request

The request shall have the following syntax:

    POST SP "/" {/resource} SP version CRLF

    Accept: 1#media-type CRLF

    Content-Type: dicom-media-type CRLF

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    *(header-field CRLF)

    CRLF

    payload

#### 10.5.1.1 Target Resources

##### 10.5.1.1.1 DICOM Resources

Table 10.5.1-1 defines the resources used to store Instances.

Table 10.5.1-1. Store Transaction DICOM Resources

Resource | URI Template | Description
--- | --- | ---
Studies |
    /studies
| Stores a set of representations that may have different Study Instance UIDs.
Study |
    /studies/{study}
| Stores a set of representations that belong to the same Study, i.e., each representation shall have the same Study Instance UID.

#### 10.5.1.2 Query Parameters

The Store transaction has no Query Parameters.

#### 10.5.1.3 Request Header Fields

The origin server shall support Header Fields as required in Table 10.5.1-2.

The user agent shall supply in the request Header Fields as required in Table 10.5.1-2.

Table 10.5.1-2. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | media-type | M | M | The DICOM Media Type of the request payload Shall be present if the request has a payload
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 10.5.1.4 Request Payload

The request payload shall be present and shall contain one or more representations specified by the Content-Type header field.

The payload may contain Instances from more than one Study if the Study Instance UID is not specified in the Target URI.

The request payload shall consist of either:

- PS3.10 SOP Instances, or

- Metadata accompanied by Bulkdata.

PS3.10 binary instances shall be encoded with one message part per DICOM Instance.

Metadata and Bulkdata requests will be encoded in the following manner (see Figure 8.6-1 Mapping between IOD and HTTP message parts):

- All XML request messages shall be encoded as described in the Native DICOM Model defined in PS3.19 with one message part per XML object; the Attributes of the Image Pixel Description Macro may be omitted for the media types specified in Table 10.5.2-1.

- All JSON request messages shall be encoded as an array of DICOM JSON Model Objects defined in Annex F in a single message part; the Attributes of the Image Pixel Description Macro may be omitted for the media types specified in Table 10.5.2-1.

- Bulkdata (with the exception of Encapsulated Document (0042,0011) element) and uncompressed pixel data shall be encoded in a Little-Endian format using the application/octet-stream media type with one message part per Bulkdata item.

- Compressed pixel data shall be encoded in one of two ways:

  - single-frame pixel data encoded using a single-frame media type (one message part);

  - multi-frame or video pixel data encoded using a multi-frame media type (multiple frames in one message part).

Uncompressed Bulkdata shall be encoded as application/octet-stream.

An Encapsulated Document (0042,0011) Bulkdata element shall be encoded using the media-type from the MIME Type of the Encapsulated Document (0042,0012) Attribute with one message part per document.

### 10.5.2 Behavior

The origin server stores Instances from the representations contained in the request payload.

The stored Instance(s) shall fully conform to the IOD and encoding requirements of PS3.3 and PS3.5, respectively.

This Transaction stores one or more new Instances, and adds them to new or existing Series and Studies.

While creating resources from the representations, the origin server may coerce or replace the values of data elements. For example, Patient Name, Patient ID, and Accession Number might be coerced when importing media from an external institution, reconciling the Instances against a master patient index, or reconciling them against an imaging procedure order. The origin server may also fix incorrect values, such as Patient Name or Patient ID; for example, because an incorrect work list item was chosen, or an operator input error has occurred.

If any Attribute is coerced or corrected, the Original Attribute Sequence (0400,0561) shall be included in the DICOM Object that is stored and may be included in the Store Instances Response Module (see Annex I) in the response.

### Note

For more information on populating the Original Attribute Sequence see Section C.12.1 “SOP Common Module” in PS3.3.

The origin server shall encapsulate or convert any compressed pixel data received as Bulkdata into an appropriate DICOM Transfer Syntax, as defined in Table 10.5.2-1.

If the request message contains compressed Bulkdata with a Content Type that is one of the media types specified in Table 10.5.2-1, the request may omit the Image Pixel Description Macro Attributes and the origin server will derive them from the compressed octet stream. Some media types do not directly correspond to a DICOM Transfer Syntax and the origin server will transform the received bit stream into an uncompressed or lossless (reversibly) compressed Transfer Syntax.

### Note

1. This allows a user agent to use consumer media types to encode the pixel data even though it may not have:

   - the pixel data in a form that directly corresponds to a lossless (reversible) DICOM Transfer Syntax, or

   - an API to access the information required to populate the Image Pixel Description Macro.

2. If the supplied compressed bit stream is in a lossless (reversible) format, the intent is to allow full fidelity retrieval of the decompressed pixels, not the format in which it happened to be submitted.

The origin server shall encapsulate or convert any compressed pixel data received as bulk data into an appropriate DICOM Transfer Syntax, as defined in Table 10.5.2-1.

If the supplied compressed octet stream is in a lossy (irreversible) format, there will be a corresponding DICOM Transfer Syntax, and the origin server is not expected to recompress it causing further loss. Table 10.5.2-1 contains a list of media types containing compressed pixel data from which an origin server shall be able to derive the Image Pixel Data Description Macro Attribute values.

Requirements are specified in Table 10.5.2-1 as follows:

Transform

  No DICOM Transfer Syntax exists; shall be transformed by the origin server into an uncompressed or lossless compressed Transfer Syntax (the choice of which is at the discretion of the origin server).

Unchanged

  Shall be encapsulated in the corresponding DICOM Transfer Syntax without further lossy compression.

Table 10.5.2-1. Media Type Transformation to Transfer Syntaxes

Media Type | Requirement
--- | ---
image/gif | Transform
Image/jp2 | Unchanged
image/jpeg | Unchanged
image/jpx | Unchanged
image/png | Transform
video/mp4 | Unchanged
video/mpeg2 | Unchanged

### Note

1. In the case of pixel data supplied as image/gif or image/png, the origin server may transform the color representation from indexed color to true color (RGB) as necessary to conform to any Photometric Interpretation constraints specified by the IOD (i.e., if PALETTE COLOR is not permitted) ; such a transformation is considered lossless.

2. If the number of bits per channel of an image/png file is not supported by the IOD, a lossless transformation cannot be performed.

3. An animated image/gif will be converted into a multi-frame image; image/png does not support animation, and Multiple-image Network Graphics (MNG) is not included in Table 10.5.2-1.

4. Any transparency information present in an image/gif or image/png file will be discarded, since DICOM does not support the concept of transparency.

5. If an alpha channel is supplied in an image/png file, and the IOD does not support the RGBA Photometric Interpretation, the alpha channel will be discarded (i.e., considered to consist of all opaque values, consistent with the policy of discarding any transparency information).

### 10.5.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint CRLF / Content-Encoding: encoding CRLF) ]

    *(header-field CRLF)

    CRLF

    store-instances-response-module

The response shall contain an appropriate status code.

If any element is coerced or corrected, the Original Attribute Sequence (0400,0561) shall be included in the DICOM Object that is stored and may be included in the Store Instances Response Module (see Annex I) in the response.

#### 10.5.3.1 Status Codes

Table 10.5.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 10.5.3-1. Status Code Meaning

Status | Code | Description
--- | --- | ---
Success | 200 (OK) | The origin server successfully stored all Instances.
202 (Accepted) | The origin server stored some of the Instances but warnings or failures exist for others. Additional information regarding this error may be found in the response message body.
Failure | 400 (Bad Request) | The origin server was unable to store any instances due to bad syntax.
409 (Conflict) | The request was formed correctly but the origin server was unable to store any instances due to a conflict in the request (e.g., unsupported SOP Class or Study Instance UID mismatch). This may also be used to indicate that the origin server was unable to store any instances for a mixture of reasons. Additional information regarding the instance errors may be found in the payload.
415 (Unsupported Media Type) | The origin server does not support the media type specified in the Content-Type header field of the request

#### 10.5.3.2 Response Header Fields

The origin server shall support header fields as required in Table 10.5.3-2.

Table 10.5.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M | The media type of the response payload, if present.
Content-Encoding | encoding | C | Shall be present if the response payload has a content encoding. See Section 8.4.3.
Content-Length | uint | C | Shall be present if the response payload does not have a content encoding. See Section 8.4.3.
Content-Location | url | C | Shall be present if a new resource was created. The value is the URL of the representation contained in the request payload. May be present otherwise
Location | url | C | Shall be present if a new resource was created. The value is the URL of the created resource. May be present otherwise

All success responses shall also contain the Content Representation (see Section 8.4.2) and Payload header fields (see Section 8.4.3) with appropriate values.

It is recommended that the text returned in the Warning header field (see [RFC7234] Section 5.5) contain a DICOM Status Code (see PS3.4 and Annex C “Status Type Encoding (Normative)” in PS3.7) and descriptive reason. For example:

    Warning: A700 <service>: Out of memory

See also Section 8.4.

#### 10.5.3.3 Response Payload

A success response payload shall contain a Store Instances Response Module. See Annex I.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

### 10.5.4 Media Types

The origin server shall support the default and required media types in the media type category specified in Table 10.5.4-1.

Table 10.5.4-1. Default, Required, and Optional Media Types

Media Type | Usage | Section
--- | --- | ---
application/dicom | Required | Section 8.7.3.1
application/dicom+json | Default | Section 8.7.3.2
multipart/related; type="application/dicom+xml" | Required | Section 8.7.3.2

### 10.5.5 Conformance Statement

An implementation conforming to the Store transaction shall support the resources and media types specified in Section 10.5.

An implementation shall declare in its Conformance Statement the SOP Classes supported for the Store transaction, and whether it plays the role of origin server or user agent, or both.

Implementation specific warning and error codes shall be included in the Conformance Statement.

## 10.6 Search Transaction

This Transaction uses the GET method to Search for Studies, Series, and Instances managed by the origin server.

### 10.6.1 Request

The request shall have the following syntax:

    GET SP "/" {/resource} {?search*} SP version CRLF

    Accept: 1#search-media-type CRLF

    *(header-field CRLF)

    CRLF

Where

    search-media-type =multipart/related; type="application/dicom+xml"/ dicom-json

#### 10.6.1.1 Target Resources

The Target Resource Path component of the Target URI specifies the collection of resources that is the target of the search.

An origin server that is a native implementation shall support all Mandatory (M) resources specified in the Native column in Table 10.6.1-1.

An origin server that is a DIMSE Proxy implementation shall support all Mandatory (M) resources specified in the Proxy column in Table 10.6.1-1.

Table 10.6.1-1. Search Transaction Resources

Resource | URI Template | Native | Proxy | Query Type
--- | --- | --- | --- | ---
All Studies |
    /studies{?search*}
| M | M | hierarchical
Study's Series |
    /studies/{study}/series{?search*}
| M | M | hierarchical
Study's Instances |
    /studies/{study}/instances{?search*}
| M | O | relational
All Series |
    /series{?parameter*}
| M | O | relational
Study's Series' Instances |
    /studies/{study}/series/{series}/instances{?search*}
| M | M | hierarchical
All Instances |
    /instances{?search*}
| M | O | relational

For more information about Hierarchical Queries see Section C.4.1.3.1.1 “Hierarchical Search Method” in PS3.4. For more information about Relational Queries see Section C.4.1.2.2.1 “Relational-Queries” in PS3.4 and Section C.4.1.3.2.1 “Relational-Queries” in PS3.4 .

Table 10.6.1-2 shows the resources supported by the Search transaction along with a description of the search performed and the results returned.

Table 10.6.1-2. Search Resource Descriptions

Resource | Description
--- | ---
All Studies | Searches the entire service for Studies that match the search parameters, and returns a list of matching Studies, including the default and requested Attributes that are supported for each Study.
Study's Series | Searches for all Series in the specified Study that match the search parameters, and returns a list of matching Series, including the default and requested Attributes that are supported for each Series.
Study's Instances | Searches for all Instances in the specified Study that match the search parameters, and returns a list of matching Instances, including the default and requested Attributes that are supported for each Instance.
All Series | Searches the entire service for Series that match the search parameters, and returns a list of matching Series, including the default and requested Attributes that are supported for each Series.
Study Series' Instances | Searches for all Instances in the specified Study and Series that match the search parameters, and returns a list of matching Instances, including the default and requested Attributes that are supported for each Series.
All Instances | Searches the entire service for Instances that match the search parameters, and returns a list of matching Instances, including the default and requested Attributes that are supported for each Series.

#### 10.6.1.2 Query Parameters

The origin server shall support Query Parameters as required in Table 8.3.4-1 for the corresponding Resource Categories.

The origin server shall support Query Parameters as required in Table 8.3.4-1 for the supported Resource Categories.

##### 10.6.1.2.1 Attribute/Value Pair Requirements

DICOM Attribute/Value pairs included as Query Parameters in the request shall satisfy the requirements in Section 8.3.4.1.

The user agent may include the following Attributes in the request:

- Patient IE Attributes (see Section 10.6.1.2.3)

- Study IE Attributes (only allowed if the resource is All Studies, All Series, All Instances)

- Series IE Attributes (only allowed if the resource is Study's Series, All Series, Study's Instances, or All Instances)

- Composite Instance IE Attributes (only allowed if the resource is Study's Instances, Study Series' Instances, or All Instances)

- Additional Query/Retrieve Attributes (see Section C.3.4 in PS3.4 )

- Timezone Offset From UTC (0008,0201)

The following are examples of Search URIs with valid Attribute/value pairs:

    /studies?PatientID=11235813

    /studies?PatientID=11235813&StudyDate=20130509

    /studies?00100010=SMITH*&00101002.00100020=11235813&limit=25

    /studies?00100010=SMITH*&OtherPatientIDsSequence.00100020=11235813

    /studies?PatientID=11235813&includefield=00081048,00081049,00081060

    /studies?PatientID=11235813&includefield=00081048&includefield=00081049&includefield=00081060

    /studies?PatientID=11235813&StudyDate=20130509-20130510

    /studies?StudyInstanceUID=1.2.392.200036.9116.2.2.2.2162893313.1029997326.94587,1.2.392.200036.9116.2.2.2.2162893313.1029997326.94583

##### 10.6.1.2.2 Search Key Types and Requirements

Table 10.6.1-3 defines the Search Key Types and their requirements.

Table 10.6.1-3. Search Key Types

Type | Requirement
--- | ---
U | Unique and Required Key
R | Required Key
C | Conditional Key
O | Optional Key

##### 10.6.1.2.3 Required Matching Attributes

The origin server shall support the IE Levels specified in Table 10.6.1-4.

Table 10.6.1-4. Required IE Levels by Resource

Resource | IE Level
--- | ---
Study | Series | Instance
All Studies | X |  |
Study's Series |  | X |
Study's Instances |  | X | X
All Series | X | X |
Study Series' Instances |  |  | X
All Instances | X | X | X

The origin server shall support the matching Attributes specified in Table 10.6.1-5 for each supported IE Level.

Table 10.6.1-5. Required Matching Attributes

IE Level | Attribute Name | Tag
--- | --- | ---
Study | Study Date | (0008,0020)
Study Time | (0008,0030)
Accession Number | (0008,0050)
Modalities In Study | (0008,0061)
Referring Physician Name | (0008,0090)
Patient Name | (0010,0010)
Patient ID | (0010,0020)
Study Instance UID | (0020,000D)
Study ID | (0020,0010)
Series | Modality | (0008,0060)
Series Instance UID | (0020,000E)
Series Number | (0020,0011)
Performed Procedure Step Start Date | (0040,0244)
Performed Procedure Step Start Time | (0040,0245)
Request Attributes Sequence | (0040,0275)
>Scheduled Procedure Step ID | (0040,0009)
>Requested Procedure ID | (0040,1001)
Instance | SOP Class UID | (0008,0016)
SOP Instance UID | (0008,0018)
Instance Number | (0020,0013)

### Note

While some of the Data Elements in Table 10.6.1-5 in are optional in Section C.6.2.1 in PS3.4 , the above list is consistent with those required for IHE RAD-14. See [IHE RAD TF Vol2] Table 4.14-1.

#### 10.6.1.3 Request Header Fields

The origin server shall support header fields as required in Table 10.6.1-6 in the request.

The user agent shall supply in the request header fields as required in Table 10.6.1-6.

Table 10.6.1-6. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | The Acceptable Media Types for the response payload
Accept-Charset | charset | O | M | The Acceptable Character Sets of the response payload

See also Section 8.4.

#### 10.6.1.4 Request Payload

The request has no payload.

### 10.6.2 Behavior

The origin server shall perform the search indicated by the request, using the matching rules in Section 8.3.4.

### 10.6.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [Content-Location: url CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    *(header-field CRLF)

    CRLF

    [payload / status-report]

#### 10.6.3.1 Status Codes

Table 10.6.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 10.6.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The search completed successfully, and the results are contained in the payload. If there are additional results available or there are warnings the Warning header field shall contain a URL referencing a Search Status report.
204 (No Content) | The search completed successfully, but there were zero results.
Failure | 400 (Bad Request) | The was a problem with the request. For example, the Query Parameter syntax is incorrect.
413 (Payload Too Large) | The search was too broad, and the body of the response should contain a Status Report with additional information about the failure.

#### 10.6.3.2 Response Header Fields

The origin server shall support header fields as required in Table 10.6.3-2.

Table 10.6.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | The DICOM Media Type of the response payload Shall be present if the response has a payload
Content-Length | uint | C | Shall be present if no content coding has been applied to the payload
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload

#### 10.6.3.3 Response Payload

A success response shall contain a list of matching results in an Acceptable Media Type. See Section 8.7.4.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

##### 10.6.3.3.1 Study Resource

For each matching Study, the origin server response shall contain Attributes in accordance with Table 10.6.3-3. The "Type" column in the table below refers to the Query/Retrieve Attribute Types defined in Section C.2.2.1 “Attribute Types” in PS3.4. The unique key for a Study resource Search response is the Study Instance UID (0020,000D).

Table 10.6.3-3. Study Resource Search Response Payload

Attribute Name | Tag | Type | Condition
--- | --- | --- | ---
Specific Character Set | (0008,0005) | C | Shall be present if known
Study Date | (0008,0020) | R |
Study Time | (0008,0030) | R |
Accession Number | (0008,0050) | R |
Instance Availability | (0008,0056) | C | Shall be present if known
Modalities in Study | (0008,0061) | R |
Referring Physician's Name | (0008,0090) | R |
Timezone Offset From UTC | (0008,0201) | C | Shall be present if known
Retrieve URL | (0008,1190) | C | Shall be present if the Instance is retrievable by the Retrieve transaction
Patient's Name | (0010,0010) | R |
Patient ID | (0010,0020) | R |
Patient's Birth Date | (0010,0030) | R |
Patient's Sex | (0010,0040) | R |
Study Instance UID | (0020,000D) | U |
Study ID | (0020,0010) | R |
Number of Study Related Series | (0020,1206) | R |
Number of Study Related Instances | (0020,1208) | R |

### Note

While some of the above Attributes are optional in Table C.6-1 “Patient Level Attributes for the Patient Root Query/Retrieve Information Model” in PS3.4, they are consistent with those required in [IHE RAD TF Vol2] Table 4.14-1.

In addition, the response shall contain:

- All other Study level Attributes passed as match or includefield parameters in the request that are supported by the origin server.

- If the includefield parameter has been specified in the request, and its value is "all", all available Study Level Attributes.

Series or Instance Level Attributes contained in includefield parameters shall not be returned.

##### 10.6.3.3.2 Series Resources

For each matching Series, the origin server shall return all Attributes listed in Table 10.6.3-4. The "Type" column in the table below refers to the Query/Retrieve Attribute Types defined in Section C.2.2.1 “Attribute Types” in PS3.4. The unique key for a Series resource Search response is the Series Instance UID (0020,000E).

Table 10.6.3-4. Series Resources Search Response Payload

Attribute Name | Tag | Type | Condition
--- | --- | --- | ---
Specific Character Set | (0008,0005) | C | Shall be present if known
Modality | (0008,0060) | R |
Timezone Offset From UTC | (0008,0201) | C | Shall be present if known
Series Description | (0008,103E) | C | Shall be present if known
Retrieve URL | (0008,1190) | R | Shall be present if the Instance is retrievable by the Retrieve transaction
Series Instance UID | (0020,000E) | U |
Series Number | (0020,0011) | R |
Number of Series Related Instances | (0020,1209) | R |
Performed Procedure Step Start Date | (0040,0244) | C | Shall be present if known
Performed Procedure Step Start Time | (0040,0245) | C | Shall be present if known
Request Attributes Sequence | (0040,0275) | C | Shall be present if known
>Scheduled Procedure Step ID | (0040,0009) | R |
>Requested Procedure ID | (0040,1001) | R |

### Note

While some of the above Attributes in are optional in Table C.6-1 “Patient Level Attributes for the Patient Root Query/Retrieve Information Model” in PS3.4, they are consistent with the those required in [IHE RAD TF Vol2] Table 4.14-1.

In addition, the response shall contain:

- All other Series Level Attributes passed as match Query Parameters, or Series or Study Level Attributes passed as includefield parameters in the request that are supported by the origin server.

- If the "includefield" parameter has been specified in the request and its value is "all", include all available Series Level Attributes.

- If the Target Resource is All Series, then include all Study Level Attributes specified in Section 10.6.3.3.1.

Instance Level Attributes contained in includefield parameters shall not be returned.

##### 10.6.3.3.3 Instance Resources

For each matching Instance, the origin server shall return all Attributes listed in Table 10.6.3-5, if present in the Instance. The Type column in the table below refers to the Query/Retrieve Attribute Types defined in Section C.2.2.1 “Attribute Types” in PS3.4. The unique key for an Instance resource search response is the SOP Instance UID (0008,0018).

Table 10.6.3-5. Instance Resources Search Response Payload

Attribute Name | Tag | Type | Condition
--- | --- | --- | ---
Specific Character Set | (0008,0005) | C | Shall be present if known
SOP Class UID | (0008,0016) | R |
SOP Instance UID | (0008,0018) | U |
Instance Availability | (0008,0056) | C | Shall be present if known
Timezone Offset From UTC | (0008,0201) | C | Shall be present if known
Retrieve URL | (0008,1190) | R | Shall be present if the Instance is retrievable by the Retrieve transaction
Instance Number | (0020,0013) | R |
Rows | (0028,0010) | C | Shall be present if known
Columns | (0028,0011) | C | Shall be present if known
Bits Allocated | (0028,0100) | C | Shall be present if known
Number of Frames | (0028,0008) | C | Shall be present if known

### Note

While some of the above Attributes in are optional in Table C.6-1 “Patient Level Attributes for the Patient Root Query/Retrieve Information Model” in PS3.4, they are consistent with the those required in [IHE RAD TF Vol2] Table 4.14-1.

In addition, the response shall contain:

- All other Instance Level Attributes passed as match parameters, or Study, Series, or Instance Level Attributes passed as includefield parameters that are supported by the origin server.

- If the "includefield" parameter has been specified in the request and its value is "all", Attribute include all available Instance Level Attributes

- If the Target Resource is All Instances, then include all Study level Attributes specified in Section 10.6.3.3.1.

- If the Target Resource is All Instances or Study's Instances, then include all Series level Attributes specified in Section 10.6.3.3.2.

### 10.6.4 Media Types

The origin server shall support the default and required media types in the media type category specified in Table 10.6.4-1.

Table 10.6.4-1. Default, Required, and Optional Media Types

Media Type | Usage | Section
--- | --- | ---
application/dicom | Required | Section 8.7.3.1
application/dicom+json | Default | Section 8.7.3.2
multipart/related; type="application/dicom+xml" | Required | Section 8.7.3.2

### 10.6.5 Conformance Statement

An implementation shall declare in its Conformance Statement whether it plays the role of origin server or user agent, or both.

An implementation playing the role of origin server shall declare the maximum number of matches supported for a single query.

An implementation playing the role of origin server shall declare its support for the following in its Conformance Statement:

- Whether it is a native or proxy implementation

- Fuzzy Matching

- Optional resources supported

- Optional Attributes supported

# 11 Worklist Service and Resources

## 11.1 Overview

The Worklist Service, also known as UPS-RS, defines a RESTful interface to the Unified Procedure Step Service SOP Classes defined in Section B.26 “Unified Procedure Step Information Object Definition” in PS3.3 and Section CC “Unified Procedure Step Service and SOP Classes (Normative)” in PS3.4, in which UPS behavior is specified.

The Worklist Service manages a single Worklist containing one or more Workitems. Each Workitem represents a procedure step. User agents and origin servers can create, retrieve, update, search for, and change the state of Workitems. See Section GGG “Unified Worklist and Procedure Step - UPS (Informative)” in PS3.17 for an overview of Worklists and Workitems (UPS Instances).

### 11.1.1 Resource Description

There are three resources defined by this service:

worklist | A collection of Workitems managed by the origin server.
workitem | A dataset containing the Attributes specified in Section CC.2.5.1.3 “UPS Attribute Service Requirements” in PS3.4.
subscription | A resource that specifies a Subscriber, to whom notifications about changes in the resource's state should be sent.

In the Worklist Service, the Workitem is identified by a Workitem UID, which corresponds to the Affected SOP Instance UID and Requested SOP Instance UID used in the PS3.4 UPS Service.

The following URI Template variables are used in the definitions of the resources throughout Chapter 11.

{workitem} | the Workitem UID.
{aetitle} | The Application Entity Title of a Subscriber.

The Worklist Service manages a UPS Worklist and its Workitems. The URI Templates defined by this service are specified in Table 11.1.1-1.

Table 11.1.1-1. Resources, URI Templates and Descriptions

Resource | URI Template | Description
--- | --- | ---
Worklist | / | The Base URI of the Worklist Service. A Worklist contains and manages a collection of Workitems. There is only one Worklist per service.
All Workitems | /workitems | The Workitems resource contains the entire collection of workitems in the Worklist.
Workitem | /workitems/{workitem} | The Workitem resource contains a single Workitem.
Workitem State | /workitems/{workitem}/state | The Workitem State resource is used to change the state of a Workitem.
Workitem Request Cancellation | /workitems/{workitem}/cancelrequest | The Workitem Cancel resource is used to request the cancellation of a Workitem.
Workitem Subscription | /workitems/{workitem}/subscribers/{aetitle} | The Subscription to a Workitem.
Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5/subscribers/{aetitle} | The Workitem Subscription resource contains a Subscription to the Worklist
Filtered Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5.1/subscribers/{aetitle} | The Workitem Subscribers resource contains a single Worklist Subscriber.

#### 11.1.1.1 Workitems

A Workitem is what is referred to in Annex CC “Unified Procedure Step Service and SOP Classes (Normative)” in PS3.4 as a procedure step.

Workitems represent a variety of steps such as: Image Processing, Quality Control, Computer Aided Detection, Interpretation, Transcription, Report Verification, or Printing. The steps may or may not be formally scheduled.

#### 11.1.1.2 Web Services and DIMSE Terminology

Table 11.1.1-2. Correspondence between RESTful and DIMSE Terminology

RESTful Term | DIMSE Term
--- | ---
Worklist | Worklist
Workitem | UPS Instance
Deletion Lock | Deletion Lock
Filter | Matching Keys
Matching Key | Matching Key
Subscribe | Subscribe
Unsubscribe | Unsubscribe
Subscription | Subscription
Subscription Generator | Worklist Subscription Filtered Worklist Subscription
Subscriber | Subscriber
Suspend Subscription | Suspend Worklist Subscription
Notification Connection | Association
Transaction | N-GET, N-SET, N-ACTION
Notification | N-EVENT-REPORT

### 11.1.2 Common Query Parameters

The origin server shall support Query Parameters as required in Table 11.1.2-1.

The user agent shall supply in the request Query Parameters as required in Table 11.1.2-1.

Table 11.1.2-1. Common Query Parameters

Name | Value | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | Section 8.3.3.1
Accept-Charset | charset | O | M | Section 8.3.3.2

See also Section 8.4.

### 11.1.3 Common Media Types

The origin server shall support the media types listed as Default or Required in Table 11.1.3-1.

Table 11.1.3-1. Default, Required, and Optional Media Types

Media Type | Usage | Section
--- | --- | ---
application/dicom+json | Default | Section 8.7.3.2
multipart/related; type="application/dicom+xml" | Required | Section 8.7.3.2

multipart/related; type="application/dicom+xml"; boundary={boundary}

  Specifies that the payload is a multipart message body where each part is a PS3.19 Native DICOM Model XML Infoset containing the appropriate Workitem Attributes. See Section A.1 in PS3.19 .

application/dicom+json

  Specifies that the payload is a JSON array containing Workitems, and each Workitem contains the appropriate Attributes. SeeSection F.2.

The transactions shall not support Metadata or Bulkdata objects.

## 11.2 Conformance

An origin server shall support all transactions of this service. Additional requirements for an origin server that is also a Unified Worklist and Procedure Step SCP are described in Section CC.1 in PS3.4 .

A user agent or origin server implementing the Worklist Service shall comply with all requirements placed on the SCU or SCP, respectively, for the corresponding services in Annex CC “Unified Procedure Step Service and SOP Classes (Normative)” in PS3.4 including Conformance Statement requirements.

An implementation supporting the Worklist Service shall describe its support in its Conformance Statement and in its response to the Retrieve Capabilities transaction, and whether it plays the role of origin server, user agent, or both.

## 11.3 Transactions Overview

The Worklist Service consists of the Transactions in Table 11.3-1.

Table 11.3-1. Worklist Service Methods and Resource Templates

Transaction | Method | Payload | Description
--- | --- | --- | ---
Request | Success Response
Create | POST | dataset | none | Creates a new Workitem
Retrieve | GET | none | dataset | Retrieves the Target Workitem
Update | POST | dataset | none | Updates the Target Workitem
Change State | PUT | none | none | Changes the state of the Target Workitem
Request Cancellation | POST | dataset | none | Requests that the origin server cancel a Workitem
Search | GET | none | results | Searches for Workitems
Subscribe | POST | none | none | Creates a Subscription to the Target Worklist or Target Workitem
Unsubscribe | DELETE | none | none | Cancels a Subscription from the Target Worklist or Target Workitem

The details of all state transition requirements can be found in Section CC.1.1 “Unified Procedure Step States” in PS3.4.

The Request Cancellation transaction does not perform an actual state transition, but it might cause a state transition.

When creating a new Workitem, to convey the Workitem UID that is to be assigned, DIMSE uses the Affected SOP instance UID in the DIMSE header. In the Web Services, the Workitem UID is included as a Query Parameter to the Create request. All Attributes in the HTTP transaction payloads are the same as those in the DIMSE payload.

## 11.4 Create Workitem Transaction

This transaction creates a Workitem on the target Worklist. It corresponds to the UPS DIMSE N-CREATE operation.

### 11.4.1 Request

The request shall have the following syntax:

    POST SP /workitems ?{workitem} SP version CRLF

    Accept: dicom-media-type CRLF

    Content-Type: dicom-media-type CRLF

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    *(header-field CRLF)

    CRLF

    Workitem

The user agent shall conform to the SCU behavior specified in Section CC.2.5.2 “Service Class User Behavior” in PS3.4.

#### 11.4.1.1 Target Resources

The Target Resource is either the Worklist, or a Workitem.

Table 11.4.1-1. Create Transaction Resources

Resource | URI Template
--- | ---
Worklist | /workitems
Workitem | /workitems?{workitem}

If the Target Resource is the Worklist, then the Workitem dataset in the payload shall contain the Workitem UID

The value of the workitem Query Parameter is the Workitem UID, which corresponds to the Affected SOP Instance UID of the UPS DIMSE N-CREATE operation.

#### 11.4.1.2 Query Parameters

The origin server shall support Query Parameters as required in Section 11.1.2.

The user agent shall supply in the request Query Parameters as required in Section 11.1.2.

#### 11.4.1.3 Request Header Fields

The origin server shall support header fields in Table 11.4.1-3.

The user agent shall supply in the request header fields as defined in Table 11.4.1-3.

Table 11.4.1-3. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | dicom-media-type | M | M | The media-type of the payload
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 11.4.1.4 Request Payload

The payload shall have a single part, containing a Workitem encoded in the media type specified in the Content-Type header field. The payload shall contain all data elements to be stored. The Affected SOP Instance UID shall not be present in the Workitem dataset.

The Workitem in the payload shall comply with all Instance requirements in the Req. Type N-CREATE column of Table CC.2.5-3 “UPS SOP Class N-CREATE/N-SET/N-GET/C-FIND Attributes” in PS3.4.

### 11.4.2 Behavior

The origin server shall create a new Workitem in the SCHEDULED state and return a URL referencing the newly created Workitem in the Location header field of the response. A Workitem will only be added to the Worklist once.

The origin server shall create and maintain the Workitem as specified by the SCP behavior defined in Section CC.2.5.3 in PS3.4 .

### 11.4.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    Content-Location: representation CRLF

    Location: resource CRLF

    *(header-field CRLF)

    CRLF

    [status-report]

#### 11.4.3.1 Status Codes

Table 11.4.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.4.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 201 (Created) | The Target Workitem was successfully added to the Worklist.
Failure | 400 (Bad Request) | There was a problem with the request. For example, the request payload did not satisfy the requirements of the Req. Type N-CREATE column of Table CC.2.5-3 “UPS SOP Class N-CREATE/N-SET/N-GET/C-FIND Attributes” in PS3.4.
409 (Conflict) | The Target Workitem already exists.

#### 11.4.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.4.3-2.

Table 11.4.3-2. Response Header Fields

Names | Value | Origin Server Usage | Condition
Content-Type | media-type | C | Shall be present if the response has a payload
Content-Length | uint | C | Shall be present if a content coding has not been applied to the payload
Content-Encoding | encoding | C | Shall be present if content encoding has been applied to the payload
Content-Location | url | O | Shall be present if the response has a payload containing a resource. See Section 8.4.3. May be present otherwise
Location | url | C | A URL-reference to the created Workitem. Shall be present if a Workitem was created. May be present if the payload contains a resource
Warning | See below | C | Shall be present if the Target Workitem was modified by the origin server and shall include the warning below

If the Target Workitem was modified by the origin server, the response shall also have the following Warning header:

    Warning: 299 <service>: The Workitem was created with modifications.CRLF

See also Section 8.4.

#### 11.4.3.3 Response Payload

A success response should have no payload.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.5 Retrieve Workitem Transaction

This transaction retrieves a Workitem. It corresponds to the UPS DIMSE N-GET operation.

### Note

The requirement for the origin server to respond to Retrieve Workitem requests for UPS Instances that have moved to the COMPLETED or CANCELED state is limited. See Section CC.2.1.3 in PS3.4 .

### 11.5.1 Request

The request shall have the following syntax:

    GET SP /workitems/{workitem} SP version CRLF

    Accept dicom-media-type CRLF

    [Cache-Control: no-cache CRLF]

    *(header-field CRLF)

    CRLF

The user agent shall conform to the SCU behavior specified in Section CC.2.7.2 “Service Class User Behavior” in PS3.4.

#### 11.5.1.1 Target Resources

The Target Resource of this transaction is a Workitem.

#### 11.5.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 11.1.2.

#### 11.5.1.3 Request Header Fields

The origin server shall support header fields as required in Table 11.5.1-1.

The user agent shall supply in the request header fields as defined in Table 11.5.1-1.

Table 11.5.1-1. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | 1#-dicom-media-type | M | M | The Acceptable Media Types of the response payload

See also Section 8.4.

#### 11.5.1.4 Request Payload

The request shall have no payload.

### 11.5.2 Behavior

If the Workitem exists on the origin server, the Workitem shall be returned in an Acceptable Media Type (see Section 8.7.4); however, the origin server may send a failure response to requests for Workitems that have moved to the COMPLETED or CANCELED state. See Section CC.2.1.3 in PS3.4 .

The returned Workitem shall not contain the Transaction UID (0008,1195) Attribute. This is necessary to preserve this Attribute's role as an access lock.

### 11.5.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [workitem / status-report]

#### 11.5.3.1 Status Codes

Table 11.5.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.5.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | All Instances were successfully retrieved.
Failure | 400 (Bad Request) | There was a problem with the request.
404 (Not Found) | The origin server has no knowledge of the Target Workitem. See Section CC.2.1.3 “Service Class Provider Behavior” in PS3.4.
409 (Conflict) | The request cannot be performed for one of the following reasons: the submitted request is inconsistent with the current state of the Target Workitem the Transaction UID is missing the Transaction UID is incorrect
410 (Gone) | The origin server knows that the Target Workitem did exist but has been deleted.

#### 11.5.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.5.3-2.

Table 11.5.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M | media type of the Target Workitem or Status Report in payload
Content-Location | url | O | Shall be present if the response has a payload containing a resource. See Section 8.4.3. May be present otherwise
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 11.5.3.3 Response Payload

A success response has a single part payload containing the requested Workitem in the Selected Media Type.

If the Workitem is in the IN PROGRESS state, the returned Workitem shall not contain the Transaction UID (0008,1195) Attribute of the Workitem, since that should only be known to the Owner.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.6 Update Workitem Transaction

This transaction modifies Attributes of an existing Workitem. It corresponds to the UPS DIMSE N-SET operation.

### 11.6.1 Request

The request shall have the following syntax:

    POST SP /workitems/{workitem}?{transaction-uid} SP version CRLF

    Content-Type: dicom-media-type CRLF

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    Content-Location: url CRLF

    *(header-field CRLF)

    CRLF

    Payload

The user agent shall conform to the SCU behavior specified in Section CC.2.6.2 “Service Class User Behavior” in PS3.4.

#### 11.6.1.1 Target Resources

The Target Resource for this transaction is a Workitem.

#### 11.6.1.2 Query Parameters

The origin server and user agent shall supply the Common Query Parameters in Section 11.1.2.

The origin server shall also supply the Transaction UID Query Parameter, which specifies the Transaction UID of the Workitem to be updated.

#### 11.6.1.3 Request Header Fields

The origin server shall support header fields as required in Table 11.6.1-1.

The user agent shall supply in the request header fields as defined in Table 11.6.1-1.

Table 11.6.1-1. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | dicom-media-type | M | M | The media-type of the payload
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 11.6.1.4 Request Payload

The request payload contains a dataset with the changes to the target Workitem. The dataset shall include all elements that are to be modified. All modifications to the Workitem shall comply with all requirements described in Section CC.2.6.2 in PS3.4 .

### 11.6.2 Behavior

The origin server shall modify the target Workitem as specified by the request, and in a manner consistent with the SCP behavior specified in Section CC.2.6.3 in PS3.4 .

If the Workitem is in the COMPLETED or CANCELED state, the response shall be a 400 (Bad Request) failure response.

### 11.6.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: workitem CRLF

    *(header-field CRLF)

    CRLF

    [status-report]

#### 11.6.3.1 Status Codes

The response shall contain an appropriate status code.

Table 11.6.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.6.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The Target Workitem was updated.
Failure | 400 (Bad Request) | There was a problem with the request. For example: the Target Workitem was in the COMPLETED or CANCELED state the Transaction UID is missing the Transaction UID is incorrect, or the dataset did not conform to the requirements
404 (Not Found) | The Target Workitem was not found.
409 (Conflict) | The request is inconsistent with the current state of the Target Workitem
410 (Gone) | The Target Workitem once existed, but no longer exists.

#### 11.6.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.6.3-2.

Table 11.6.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M | The media-type of the payload
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload
Content-Location | url | O | Shall be present if the response has a payload containing a resource. See Section 8.4.3. May be present otherwise
Warning | see below | O | If the Target Workitem was modified by the origin server shall include one of the Warning header fields below.

If the Workitem was successfully updated but with modifications made by the origin server, the response shall include the following in the Warning header field:

    Warning: 299 <service>: The Workitem was updated with modifications.

If optional Attributes were rejected, the response shall include the following Warning header field:

    Warning: 299 <service>: Requested optional Attributes are not supported.

If the request was rejected with a failure status code, the response shall include a Warning header field with one of following messages that best describes the nature of the conflict:

    Warning: 299 <service>: The target URI did not reference a claimed Workitem.

    Warning: 299 <service>: The submitted request is inconsistent with the current state of the Workitem.

See also Section 8.4.

#### 11.6.3.3 Response Payload

A success response shall have either no payload, or a payload containing a Status Report document.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.7 Change Workitem State

This transaction is used to change the state of a Workitem. It corresponds to the UPS DIMSE N-ACTION operation "Change UPS State". State changes are used to claim ownership, complete, or cancel a Workitem.

### 11.7.1 Request

The request shall have the following syntax:

    PUT SP /workitems/{workitem}/state SP version CRLF

    Content-Type: dicom-media-type

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    *(header-field CRLF)

    CRLF

    Payload

The user agent shall conform to the SCU behavior specified in Section CC.2.1.2 “Service Class User Behavior” in PS3.4.

#### 11.7.1.1 Target Resources

The Target Resource for this transaction is a Workitem.

#### 11.7.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 11.1.2.

#### 11.7.1.3 Request Header Fields

The origin server shall support header fields as required in Table 11.7.1-1.

The user agent shall supply in the request header fields as defined in Table 11.7.1-1.

Table 11.7.1-1. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | dicom-media-type | M | M | The Acceptable Media Types of the response payload
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 11.7.1.4 Request Payload

The request payload shall contain the Change UPS State Data Elements as specified in Table CC.2.1-1 “Change UPS State - Action Information” in PS3.4. These data elements are:

Transaction UID (0008,1195)

  The request payload shall include a Transaction UID. The user agent creates the Transaction UID when requesting a transition to the IN PROGRESS state for a given Workitem. The user agent provides that Transaction UID in subsequent transactions with that Workitem.

Procedure Step State (0074,1000)

  The legal values correspond to the requested state transition. They are: "IN PROGRESS", "COMPLETED", or "CANCELLED".

### 11.7.2 Behavior

The origin server shall support the state changes to the Workitem specified in the request as described by the SCP behavior in Section CC.2.1.3 “Service Class Provider Behavior” in PS3.4.

### 11.7.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    *(header-field CRLF) CRLF

    [status-report]

#### 11.7.3.1 Status Codes

Table 11.7.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.7.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The update was successful, and the response payload contains a Status Report document.
Failure | 400 (Bad Request) | The request cannot be performed for one of the following reasons: the request is invalid given the current state of the Target Workitem the Transaction UID is missing the Transaction UID is incorrect
404 (Not Found) | The Target Workitem was not found.
409 (Conflict) | The request is inconsistent with the current state of the Target Workitem
410 (Gone) | The Target Workitem once existed, but no longer exists.

#### 11.7.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.7.3-2.

Table 11.7.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M | The media-type of the payload.
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload.
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload.
Content-Location | url | O | Shall be present if the response has a payload containing a resource. See Section 8.4.3. May be present otherwise.
Warning | text | C | See below.

If the user agent specifies a Procedure Step State (0074,1000) Attribute with a value of "CANCELED" and the Workitem is already in that state, the response message shall include the following HTTP Warning header field:

    Warning: 299 <service>: The UPS is already in the requested state of CANCELED.

If the user agent specifies a Procedure Step State (0074,1000) Attribute with a value of "COMPLETED" and the UPS Instance is already in that state, the response message shall include the following HTTP Warning header field:

    Warning: 299 <service>: The UPS is already in the requested state of COMPLETED.

If the request was rejected with a failure status code, the response message shall include one of following messages in the HTTP Warning header field describing the nature of the conflict:

    Warning: 299 <service>: The Transaction UID is missing.

    Warning: 299 <service>: The Transaction UID is incorrect.

    Warning: 299 <service>: The submitted request is inconsistent with the state of the UPS Instance.

See also Section 8.4.

#### 11.7.3.3 Response Payload

A success response shall have no payload.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.8 Request Cancellation

This transaction allows a user agent that does not own a Workitem to request that it be canceled. It corresponds to the UPS DIMSE N-ACTION operation "Request UPS Cancel". See Section CC.2.2 in PS3.4 .

To cancel a Workitem that the user agent owns, i.e., that is in the IN PROGRESS state, the user agent uses the Change Workitem State transaction as described in Section 11.7.

### 11.8.1 Request

The request shall have the following syntax:

    POST SP /workitems/{workitem}/cancelrequest SP version CRLF

    Content-Type: dicom-media-type

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    *(header-field CRLF)

    CRLF

    [Payload]

The user agent shall conform to the SCU behavior specified in Section CC.2.2.2 “Service Class User Behavior” in PS3.4.

#### 11.8.1.1 Target Resources

The Target Resource for this transaction is a Workitem.

#### 11.8.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 11.1.2.

#### 11.8.1.3 Request Header Fields

The origin server shall support header fields as required in Table 11.8.1-1.

The user agent shall supply in the request header fields as defined in Table 11.8.1-1.

Table 11.8.1-1. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | dicom-media-type | M | M | The media-type of the payload.
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload.
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload.

See also Section 8.4.

#### 11.8.1.4 Request Payload

The request payload, if present, may describe the reason for requesting the cancellation of the Workitem, a Contact Display Name, and/or a Contact URI for the person with whom the cancel request may be discussed.

The Request UPS Cancel Action Information is specified in Table CC.2.2-1 “Request UPS Cancel - Action Information” in PS3.4.

### 11.8.2 Behavior

The origin server shall process the request as described by the SCP behavior in Section CC.2.2.3 “Service Class Provider Behavior” in PS3.4.

### 11.8.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type dicom-media-type CRLF]

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF) CRLF

    [status-report]

#### 11.8.3.1 Status Codes

Table 11.8.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.8.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 202 (Accepted) | The request was accepted by the origin server, but the Target Workitem state has not necessarily changed yet. ### Note The owner of the Workitem is not obliged to honor the request to cancel and, in some scenarios, may not even receive notification of the request. The owner of the Workitem is not obliged to honor the request to cancel and, in some scenarios, may not even receive notification of the request.
Failure | 400 (Bad Request) | There was a problem with the syntax of the request.
404 (Not Found) | The Target Workitem was not found.
409 (Conflict) | The request is inconsistent with the current state of the Target Workitem. For example, the Target Workitem is in the SCHEDULED or COMPLETED state.

#### 11.8.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.8.3-2.

Table 11.8.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | The media type of the Status Report document. Shall be present if the response contains a payload.
Content-Length | uint | C | Shall be present if a content encoding has not been applied to the payload.
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload.

If the Workitem Instance is already in a canceled state, the response message shall include the following HTTP Warning header field:

    Warning: 299 <service>: The UPS is already in the requested state of CANCELED.

See also Section 8.4.

#### 11.8.3.3 Response Payload

The response may include a payload containing an appropriate Status Report.

## 11.9 Search Transaction

This transaction searches the Worklist for Workitems that match the specified Query Parameters and returns a list of matching Workitems. Each Workitem in the returned list includes return Attributes specified in the request. The transaction corresponds to the UPS DIMSE C-FIND operation.

### 11.9.1 Request

The request shall have the following syntax:

    GET SP /workitems?{&match*}{&includefield}{&fuzzymatching}{&offset}{&limit} SP version CRLF

    Accept: dicom-media-types CRLF

    *(header-field CRLF)

    CRLF

The user agent shall conform to the SCU behavior specified in Section CC.2.8.2 “Service Class User Behavior” in PS3.4.

#### 11.9.1.1 Target Resources

The Target Resource for this transaction is the Worklist.

#### 11.9.1.2 Query Parameters

The origin server shall support Query Parameters as required in Table 8.3.4-1.

The user agent shall supply in the request Query Parameters as required in Table 8.3.4-1.

#### 11.9.1.3 Request Header Fields

The origin server shall support header fields as required in Table 11.9.1-1.

The user agent shall supply in the request header fields as defined in Table 11.9.1-1.

Table 11.9.1-1. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | 1#-dicom-media-type | M | M | The Acceptable Media Types of the response payload.
Cache-Control | "no-cache" | O | M | If included, specifies that search results returned should be current and not cached.

See also Section 8.4.

#### 11.9.1.4 Request Payload

The request payload shall be empty.

### 11.9.2 Behavior

The origin server shall perform a search according the requirements specified in Section 8.3.4.

For each matching Workitem, the origin server shall include in the results:

- All Unified Procedure Step Instance Attributes in Table CC.2.5-3 “UPS SOP Class N-CREATE/N-SET/N-GET/C-FIND Attributes” in PS3.4 with a Return Key Type of 1 or 2.

- All Unified Procedure Step Instance Attributes in Table CC.2.5-3 “UPS SOP Class N-CREATE/N-SET/N-GET/C-FIND Attributes” in PS3.4 with a Return Key Type of 1C for which the conditional requirements are met.

- All other Workitem Attributes passed as match parameters that are supported by the origin server as either matching or return Attributes.

- All other Workitem Attributes passed as includefield parameter values that are supported by the origin server as return Attributes.

### 11.9.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [search-results / status-report]

#### 11.9.3.1 Status Codes

Table 11.9.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.9.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The search completed successfully, and the matching results are returned in the message body.
204 (No Content) | The search completed successfully, but there were no matching results.
206 (Partial Content) | Only some of the search results were returned, and the rest can be requested through the appropriate request.
Failure | 400 (Bad Request) | The was a problem with the request. For example, invalid Query Parameter syntax.
413 (Payload Too Large) | The size of the results exceeds the maximum payload size supported by the origin server. The user agent may repeat the request with paging or with a narrower query to reduce the size of the result.

#### 11.9.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.9.3-2.

Table 11.9.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | M | The media-type of the payload.
Content-Length | Uint | C | Shall be present if a content coding has not been applied to the payload.
Content-Encoding | Encoding | C | Shall be present if a content encoding has been applied to the payload.
Content-Location | url | C | Shall be present if the response has a payload containing a resource. See Section 8.4.3. May be present otherwise.

See also Section 8.4.

#### 11.9.3.3 Response Payload

A success response payload shall contain the search results in an Acceptable Media Type. See Section 8.7.5. If there are no matching results the payload will be empty. See Section 8.6.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.10 Subscribe Transaction

This transaction creates a Subscription to a Worklist or Workitem resource. It corresponds to the UPS DIMSE N-ACTION operation "Subscribe to Receive UPS Event Reports".

Once a Subscription has been created the user agent will receive notifications containing Event Reports for events associated with the Subscription's resource. To receive the notifications generated by Subscriptions, the user agent must have first opened a Notification Connection between itself and the origin server using the Open Notification Connection transaction; see Section 8.10.4.

### 11.10.1 Request

The request shall have the following syntax:

    POST SP /workitems/{resource}/subscribers/{aetitle}{?deletionlock}{&filter} SP version CRLF

    *(header-field CRLF)

    CRLF

The user agent shall conform to the SCU behavior specified in Section CC.2.3.2 “Service Class User Behavior” in PS3.4.

#### 11.10.1.1 Target Resources

The origin server shall support the resources in Table 11.10.1-1.

Table 11.10.1-1. Subscribe Transaction Resources

Resource | URI Template
--- | ---
Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5/subscribers/{aetitle}
Filtered Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5.1/subscribers/{aetitle}
Workitem Subscription | /workitems/{workitem}/subscribers/{aetitle}

#### 11.10.1.2 Query Parameters

The origin server shall support Query Parameters as required in Table 11.10.1-2.

The user agent shall supply in the request Query Parameters as required in Table 11.10.1-2.

Table 11.10.1-2. uery Parameters by Resource

Key | Value | Resource | Usage | Description
--- | --- | --- | --- | ---
User Agent | Origin Server
accept | media type | Worklist, Filtered Worklist, Workitem | O | M |
charset | charset | Worklist, Filtered Worklist, Workitem | O | M |
deletionlock | true/false | Worklist, Filtered Worklist, Workitem | O | M |
filter | 1#(attribute"=" value) | Filtered Worklist | C | M | Shall be present if the Target Resource is the Filtered Worklist.

The Deletion Lock Query Parameter has the following syntax:

    deletionlock = "deletionlock=" true / false

If present with a value of true the Subscription will be created with a Deletion Lock (see Section CC.2.3.1 “Action Information” in PS3.4).

The Filter Query Parameter has the following syntax:

    filter = 1#(attribute "=" value)

It is a comma-separated list of one or more matching keys (attribute/value pairs). A Workitem Subscription will be created for any existing and future Workitem that matches the attribute/value pairs of the filter. The valid Attributes for this Query Parameter are defined by the UPS IOD (see Section B.26.2 “IOD Modules” in PS3.3).

See Section 8.3.4.1 for the syntax of matching keys.

#### 11.10.1.3 Request Header Fields

The request has no mandatory header fields. See Section 8.4.

#### 11.10.1.4 Request Payload

The request shall have no payload.

### 11.10.2 Behavior

The origin server shall create and manage a Subscription to the Target Resource for the user agent. The origin server shall conform to the SCP behavior specified in Section CC.2.3.3 “Service Class Provider Behavior” in PS3.4.

### 11.10.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [status-report]

#### 11.10.3.1 Status Codes

Table 11.10.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.10.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 201 (Created) | The Subscription was created.
Failure | 400 (Bad Request) | There was a problem with the syntax of the request.
403 (Forbidden) | The origin server understood the request but is refusing to perform the query (e.g., the origin server does not support Worklist Subscription Filtering, or an authenticated user has insufficient privileges).
404 (Not Found) | The Target Resource was not found.

#### 11.10.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.10.3-2.

Table 11.10.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | Shall be present if the response contains a payload.
Content-Location | url | C | A URL-reference to the WebSocket Connection. Shall be present if a Subscription was created. The URL shall include the WebSocket protocol (either WS or WSS) and may include a combination of authority and path.
Warning | String | C | See below.

If the Create Subscription request was accepted but the Deletion Lock was not, the response shall include the following Warning header field:

    Warning: 299 <service>: Deletion Lock not granted.

and may include a Status Report.

If the request was rejected with a 403 status code because Filtered Worklist Subscription is not supported, the response shall include the following Warning header field:

    Warning: 299 <service>: Filtered Worklist Subscriptions are not supported.

See also Section 8.4.

#### 11.10.3.3 Response Payload

A success response payload may contain a Status Report.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.11 Unsubscribe Transaction

This transaction is used to stop the origin server from sending new Event Reports to the user agent and may also stop the origin server from subscribing the user agent to new Workitems.

### 11.11.1 Request

The request shall have the following syntax:

    DELETE SP {/resource} SP version CRLF

    *(header-field CRLF)

    CRLF

#### 11.11.1.1 Target Resources

The origin server shall support the resources in Table 11.11.1-1.

Table 11.11.1-1. Unsubscribe Transaction Resources

Resource | URI Template
--- | ---
Workitem Subscription | /workitems/{workitem}/subscribers/{aetitle}
Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5/subscribers/{aetitle}
Filtered Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5.1/subscribers/{aetitle}

#### 11.11.1.2 Query Parameters

The request has no Query Parameters.

#### 11.11.1.3 Request Header Fields

The request has no Mandatory header fields.

#### 11.11.1.4 Request Payload

The request payload shall be empty.

### 11.11.2 Behavior

Upon receipt of an Unsubscribe request, the origin server shall attempt to remove the Workitem Subscription, Worklist Subscription, or Filtered Worklist Subscription of the specified Application Entity with respect to the specified Workitem UID, Worklist UID, or Filtered Worklist UID as described in Section CC.2.3.3 in PS3.4 and then return an appropriate response.

For a Workitem resource, this corresponds to the UPS DIMSE N-ACTION operation "Unsubscribe from Receiving UPS Event Reports".

For a Worklist or Filtered Worklist resource this transaction corresponds to the UPS DIMSE N-ACTION operation "Unsubscribe from Receiving UPS Event Reports" for the Global Subscription identified by the well-known UID.

### 11.11.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [status-report]

#### 11.11.3.1 Status Codes

Table 11.11.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.11.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The Subscription(s) were removed.
Failure | 400 (Bad Request) | There was a problem with the request. For example, the Target Workitem UID is missing.
404 (Not Found) | The target Subscription was not found.

#### 11.11.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.11.3-2.

Table 11.11.3-2. Response Header Fields

Name | Value | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | The media-type of the response payload. Shall be present if the response has a payload.
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload.
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload
Warning | text | O | A warning message.

See also Section 8.4.

#### 11.11.3.3 Response Payload

A success response shall have no payload.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.12 Suspend Global Subscription Transaction

This transaction is used to stop the origin server from automatically subscribing the User-Agent to new Workitems. This does not delete any existing subscriptions to specific Workitems.

### 11.12.1 Request

The request shall have the following syntax:

    POST SP {/resource} SP version CRLF

    *(header-field CRLF)

    CRLF

#### 11.12.1.1 Target Resources

The origin server shall support the resources in Table 11.12.1-1.

Table 11.12.1-1. Unsubscribe Transaction Resources

Resource | URI Template
--- | ---
Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5/subscribers/{aetitle}/suspend
Filtered Worklist Subscription | /workitems/1.2.840.10008.5.1.4.34.5.1/subscribers/{aetitle}/suspend

#### 11.12.1.2 Query Parameters

The request has no Query Parameters.

#### 11.12.1.3 Request Header Fields

The request has no Mandatory header fields.

#### 11.12.1.4 Request Payload

The request payload shall be empty.

### 11.12.2 Behavior

Upon receipt of a Suspend request, the origin server shall attempt to remove the Worklist Subscription, or Filtered Worklist Subscription of the specified Application Entity with respect to the specified Worklist UID, or Filtered Worklist UID as described in Section CC.2.3.3 in PS3.4 and then return an appropriate response.

This transaction corresponds to the UPS DIMSE N-ACTION operation "Suspend Global Subscription"

### 11.12.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [status-report]

#### 11.12.3.1 Status Codes

Table 11.12.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 11.12.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The Worklist Subscription was suspended.
Failure | 400 (Bad Request) | There was a problem with the request. For example, the Target Worklist UID is missing.
404 (Not Found) | The target Subscription was not found.

#### 11.12.3.2 Response Header Fields

The origin server shall support header fields as required in Table 11.12.3-2.

Table 11.12.3-2. Response Header Fields

Name | center | Origin Server Usage | Description
--- | --- | --- | ---
Content-Type | media-type | C | The media-type of the response payload. Shall be present if the response has a payload.
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload.
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload.
Warning | text | O | A warning message.

See also Section 8.4.

#### 11.12.3.3 Response Payload

A success response shall have no payload.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 11.13 Workitem Event Reports

The origin server uses the Send Event Report Transaction (see Section 8.10.5) to send a Workitem Event Report, containing the details of any state change in the Workitem to the user agent.

The origin server shall send Workitem Event Reports as described in Section CC.2.4.3 in PS3.4 .

The Event Report shall contain all mandatory Attributes described in Table CC.2.4-1 “Report a Change in UPS Status - Event Report Information” in PS3.4 and Table 10.3-2 “N-EVENT-REPORT-RSP Message Fields” in PS3.7 .

The following is an example application/dicom+json Workitem Event Report payload:

    {

    "00000002": {"vr": "UI", "Value": ["1.2.840.10008.5.1.4.34.6.4"] },

    "00000110": {"vr": "US", "Value": [23] },

    "00001000": {"vr": "UI", "Value": ["1.2.840.10008.5.1.4.34.6.4.2.3.44.22231"] },

    "00001002": {"vr": "US", "Value": [1] },

    "00404041": {"vr": "US", "Value": ["READY"] },

    "00741000": {"vr": "LT", "Value": ["SCHEDULED"] }

    } CRLF

# 12 Non-Patient Instance Service and Resources

## 12.1 Overview

The Non-Patient Instance (NPI) Storage Service enables a user agent to retrieve, store, and search an origin server for instances that are not related to a patient.

An NPI Storage Service manages a collection of resources belonging to the categories specified in Table 12.1.1-1.

All NPI Storage Service origin servers shall support the Retrieve Capabilities, Retrieve, and Search transactions. Support for the Store transaction is optional. All NPI Storage Service user agents support one or more of the Retrieve Capabilities, Retrieve, Store, or Search transactions.

### 12.1.1 Resource Descriptions

An NPI Service manages resources from the same NPI Category. Target URIs have the following templates:

    /{npi-name}
    /{npi-name}/{uid}

Where

    npi-name    = "color-palettes"
                / "defined-procedure-protocols"
                / "hanging-protocols"
                / "implant-templates"
    uid         ; is the Unique Identifier of an NPI Instance

Table 12.1.1-1 contains the templates for the NPI Resource Categories.

Table 12.1.1-1. Resource Categories, URI Templates and Descriptions

Resource Category | URI Template and Description | Corresponding IOD | Storage Class | Information Model
--- | --- | --- | --- | ---
Color Palette |
    /color-palettes{/uid}
| Section A.58 “Color Palette IOD” in PS3.3 | Section GG “Non-Patient Object Storage Service Class” in PS3.4 | Section X.1.3 “Query/Retrieve Information Model” in PS3.4
Defined Procedure Protocol |
    /defined-procedure-protocols{/uid}
| Section A.82 “Procedure Protocol Information Object Definitions” in PS3.3 | Section GG “Non-Patient Object Storage Service Class” in PS3.4 | Section HH.1.3 “Query/Retrieve Information Model” in PS3.4
Hanging Protocol |
    /hanging-protocols{/uid}
| Section A.44 “Hanging Protocol IOD” in PS3.3 | Section GG “Non-Patient Object Storage Service Class” in PS3.4 | Section U.1.3 “Query/Retrieve Information Model” in PS3.4
Implant Template |
    /implant-templates{/uid}
| Section A.61 “Generic Implant Template IOD” in PS3.3 | Section GG “Non-Patient Object Storage Service Class” in PS3.4 | Section BB.1.3 “Query/Retrieve Information Model” in PS3.4

The NPI SOP Classes are listed in Table GG.3-1 “Standard SOP Classes” in PS3.4.

### 12.1.2 Common Query Parameters

The origin server shall support Query Parameters as required in Table 12.1.2-1.

The user agent shall supply in the request Query Parameters as required in Table 12.1.2-1.

Table 12.1.2-1. Common Query Parameters

Name | Value | Usage | Section
--- | --- | --- | ---
User Agent | Origin Server
Accept | media-type | M | M | Section 8.3.3.1
Accept-Charset | charset | O | M | Section 8.3.3.2

See also Section 8.4.

### 12.1.3 Common Media Types

The origin server shall support the media types listed as Default or Required in Table 12.1.3-1 for all NPI transactions.

Table 12.1.3-1. Default, Required, and Optional Media Types

Media Type | Usage | Section
--- | --- | ---
application/dicom | Required | Section 8.7.3.1
application/dicom+json | Default | Section 8.7.3.2
multipart/related; type="application/dicom+xml" | Required | Section 8.7.3.2

## 12.2 Conformance

An origin server conforming to the NPI Service shall implement the Retrieve Capabilities Transaction (see Section 8.9.1).

The origin server shall support the transactions listed as Required in Table 12.2-1.

Table 12.2-1. Required and Optional Transactions

Transaction | Support | Section
--- | --- | ---
Retrieve Capabilities | Required | Section 8.9
Retrieve | Required | Section 12.4
Store | Optional | Section 12.5
Search | Required | Section 12.6

Implementations shall specify in their Conformance Statement (see PS3.2) and the Retrieve Capabilities Transaction (see Section 8.9 and Annex H):

- The implementations role: origin server, user agent, or both.

- The supported resources (IODs) for each role.

In addition, for each supported transaction they shall specify:

- The supported Query Parameters, including optional Attributes, if any

- The supported DICOM Media Types

- The supported character sets (if other than UTF-8)

## 12.3 Transactions Overview

The NPI Service consists of the transactions listed in Table 12.3-1.

Table 12.3-1. NPI Service Transactions

Transaction | Method | Resource | Payload | Description
--- | --- | --- | --- | ---
Request | Success Response
Retrieve Capabilities | OPTIONS | / | N/A | Capabilities Description | Retrieves a description of the capabilities of the NPI Service, including transactions, resources, query parameters, etc.
Retrieve | GET | /{npi-name}/{uid} | N/A | Instance and/or Status Report | Retrieves an Instance, specified by the Target Resource in an Acceptable DICOM Media Type.
Store | POST | /{npi-name}{/uid} | Instance(s) | Status Report | Stores one or more DICOM Instances contained in the request payload, in the location referenced by the Target URL.
Search | GET | /{npi-name} ?{params*} | N/A | Result(s) and/or Status Report | Searches the Target Resource for Instances that match the search parameters and returns a list of matches in an Acceptable DICOM Media Type.

The npi-name specifies the type of resource(s) contained in the payload.

Table 12.3-2 summarizes the Target Resources permitted for each transaction.

Table 12.3-2. Resources by Transaction

Resource | URI | Retrieve | Store | Search | Capabilities
--- | --- | --- | --- | --- | ---
NPI Service | / |  |  |  | X
All Instances | /{npi-name} |  | X | X |
Instance | /{npi-name}/{uid} | X | X |  |

## 12.4 Retrieve Transaction

The Retrieve transaction retrieves the target NPI resource in a DICOM Media Type.

### 12.4.1 Request

The request shall have the following syntax:

    GET SP /{npi-name}/{uid} SP version CRLF

    Accept: 1#dicom-media-type CRLF

    *(header-field CRLF)

    CRLF

#### 12.4.1.1 Target Resources

The target URI shall reference one of the resources shown in Table 12.4.1-1.

An origin server shall specify all supported npi-names in its Conformance Statement and in its response to the Retrieve Capabilities transaction.

Table 12.4.1-1. Retrieve Transaction Resources

Resource | URI Template
--- | ---
Instance |
    /{npi-name}/{uid}

#### 12.4.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 12.1.2.

#### 12.4.1.3 Request Header Fields

Table 12.4.1-2. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | 1#-dicom-media-type | M | M | The Acceptable Media Types of the response payload

See also Section 8.4.

#### 12.4.1.4 Request Payload

The request shall have no payload.

### 12.4.2 Behavior

The origin server shall try to locate the Target Resource and if found, return it in an Acceptable DICOM Media Type. See Section 8.7.5.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

### 12.4.3 Response

The response has the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF

    CRLF

    [payload / status-report]

#### 12.4.3.1 Status Codes

Table 12.4.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 12.4.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The instance was successfully retrieved.
Failure | 400 (Bad Request) | There was a problem with the request.
404 (Not Found) | The origin server did not find a current representation for the Target Resource or is not willing to disclose that one exists. For example, an unsupported IOD, or Instance not on server.
406 (Unsupported Media Type) | The origin server does not support any of the Acceptable Media Types.

#### 12.4.3.2 Response Header Fields

Table 12.4.3-2. Response Header Fields

Header Field | Value | Origin Server Usage | Requirements
--- | --- | --- | ---
Content-Type | dicom-media-type | M | The media-type of the response payload.
Content-Length | uint | C | Shall be present if no content encoding has been applied to the payload.
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload.

See also Section 8.4.

#### 12.4.3.3 Response Payload

A success response shall have a payload containing the DICOM instance specified by the Target Resource.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

## 12.5 Store Transaction

This transaction requests that the origin server store the representations of the NPIs contained in the request payload so that they may be retrieved in the future using the SOP Instance UIDs.

### 12.5.1 Request

The request shall have the following syntax:

    POST SP /{npi-name} {/uid} SP version CRLF

    Content-Type: dicom-media-type CRLF

    (Content-Length: uint / Content-Encoding: encoding) CRLF

    CRLF

    payload

#### 12.5.1.1 Target Resources

The Target URI shall reference one of the resources shown in Table 12.5.1-1.

An origin server shall specify all supported npi-names in its Conformance Statement and in its response to the Retrieve Capabilities transaction.

Table 12.5.1-1. Store Transaction Resources

Resource | URI Template | Description
--- | --- | ---
All Instances |
    /{npi-name}
| Stores representations of a set of Instances.
Instance |
    /{npi-name} {/uid}
| Stores a representation of a single Instance with a UID equal to uid.

#### 12.5.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 12.1.2.

#### 12.5.1.3 Request Header Fields

Table 12.5.1-2. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Content-Type | media-type | M | M | The DICOM Media Type of the request payload.
Content-Length | uint | C | M | Shall be present if a content encoding has not been applied to the payload.
Content-Encoding | encoding | C | M | Shall be present if a content encoding has been applied to the payload.

See also Section 8.4.

#### 12.5.1.4 Request Payload

The request payload shall be present and shall contain one or more representations in the DICOM Media Type specified by the Content-Type header field of the message, or for multipart payloads the Content-Type header field of each part.

### 12.5.2 Behavior

The origin server stores the representations contained in the request payload so that they may be retrieved later using the Retrieve transaction.

Before storing the representations, the origin server may coerce data elements.

If any element is coerced, the Original Attribute Sequence (0400,0561) (see Section C.12.1 “SOP Common Module” in PS3.3) shall be included in the stored DICOM instances. Both the Original Attribute Sequence and the response shall describe the modifications.

### 12.5.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF)

    CRLF

    [Status Report]

#### 12.5.3.1 Status Codes

Table 12.5.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 12.5.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The origin server successfully stored or created at least one of the representations contained in the request payload and is returning a response payload.
202 (Accepted) | The origin server successfully validated the request message but has not yet stored or created the representations in the request payload. The origin server may or may not have validated the payload. The user agent can use a Query or Retrieve transaction later to determine if the request has completed.
Failure | 400 (Bad Request) | The was a problem with the request. For example: the origin server did not store any of the representations contained in the request payload because of errors in the request message, the request contained an invalid Query Parameter, the request referenced an invalid instance.
404 (Not Found) | The origin server did not find a current representation for the Target Resource or is not willing to disclose that one exists. For example, an unsupported IOD, or Instance not on server.
409 (Conflict) | The request could not be completed due to a conflict with the current state of the Target Resource.
415 (Unsupported Media Type) | The origin server does not support the media type specified in the Content-Type header field of the request, and none of the representations contained in the request were processed or stored.

#### 12.5.3.2 Response Header Fields

Table 12.5.3-2. Response Header Fields

Header Field | Value | Origin Server Usage | Requirements
--- | --- | --- | ---
Content-Type | dicom-media-type | M | The media type of the response payload.
Content-Length | uint | C | Shall be present if a content encoding has not been applied to the payload
Content-Encoding | encoding | C | Shall be present if a content encoding has been applied to the payload

See also Section 8.4.

#### 12.5.3.3 Response Payload

If the origin server failed to store or modified any representations in the request payload, the response payload shall contain a Status Report describing any additions, modifications, or deletions to the stored representations. The Status Report may also describe any warnings or other useful information.

## 12.6 Search Transaction

The Search transaction searches the collection of NPI Instances contained in the Target Resource. The search criteria are specified in the query parameters. Each match includes the default and requested Attributes from the matching Instance. A successful response returns a list describing the matching Instances.

### 12.6.1 Request

The request shall have the following syntax:

    GET SP /{npi-name} {?parameter*} SP version CRLF

    Accept: 1#dicom-media-type CRLF

    *(header-field CRLF)

    CRLF

#### 12.6.1.1 Target Resources

The Target URI shall reference one of the resources shown in Table 12.6.1-1.

An origin server shall specify all supported npi-names in its Conformance Statement and in its response to the Retrieve Capabilities transaction.

Table 12.6.1-1. Search Transaction Resources

Resource | URI Template | Description
--- | --- | ---
All Instances | /{npi-name} | Searches a collection of NPI Instances.

#### 12.6.1.2 Query Parameters

The user agent shall supply, and the origin server shall support, the Common Query Parameters in Section 12.1.2.

The origin server shall support Query Parameters as required in Table 8.3.4-1.

The user agent shall supply in the request Query Parameters as required in Table 8.3.4-1.

For each Resource Category the origin server supports, it shall support the behaviors and matching key Attributes specified in the corresponding sections in Table 12.6.1-2.

Table 12.6.1-2. NPI Resource Search Attributes

Resource Category | Behaviors and Matching Key Attributes
--- | ---
Color Palette | Section X.6.1.2 “Color Palette Attributes” in PS3.4.
Defined Procedure Protocol | Section HH.6.1.2 “Defined Procedure Protocol Attributes” in PS3.4.
Hanging Protocol | Section U.6.1.2 “Hanging Protocol Attributes” in PS3.4.
Implant Template | Section BB.6.1.2 “Implant Template Attributes” in PS3.4.

#### 12.6.1.3 Request Header Fields

Table 12.6.1-3. Request Header Fields

Name | Values | Usage | Description
--- | --- | --- | ---
User Agent | Origin Server
Accept | 1#-dicom-media-type | M | M | The Acceptable Media Types of the response payload

See also Section 8.4.

#### 12.6.1.4 Request Payload

The request has no payload.

### 12.6.2 Behavior

The origin server shall perform the search indicated by the request, using the matching behavior specified in Section 8.3.4.1.1 and in the corresponding sections in Table 8.3.4-1.

The rules for search results are specified in Section 8.3.4.

### 12.6.3 Response

The response shall have the following syntax:

    version SP status-code SP reason-phrase CRLF

    [Content-Type: dicom-media-type CRLF]

    [(Content-Length: uint / Content-Encoding: encoding) CRLF]

    [Content-Location: url CRLF]

    *(header-field CRLF

    CRLF

    [payload / status-report]

#### 12.6.3.1 Status Codes

Table 12.6.3-1 shows some common status codes corresponding to this transaction. See also Section 8.5 for additional status codes.

Table 12.6.3-1. Status Code Meaning

Status | Code | Meaning
--- | --- | ---
Success | 200 (OK) | The query completed and any matching results are returned in the message body.
Failure | 400 (Bad Request) | The request message contained an error. For example, the Query Parameters were invalid
406 (Unsupported Media Type) | The origin server does not support any of the Acceptable Media Types.
413 (Payload Too Large) | The search was too broad, and the body of the response should contain a Status Report with additional information about the failure.

#### 12.6.3.2 Response Header Fields

Table 12.6.3-2. Response Header Fields

Header Field | Value | Origin Server Usage | Requirement
--- | --- | --- | ---
Content-Type | dicom-media-type | M | The media type of the response payload.
Content-Length | Uint | C | Shall be present if a content encoding has not been applied to the payload.
Content-Encoding | Encoding | C | Shall be present if a content coding has been applied to the payload.

See also Section 8.4.

#### 12.6.3.3 Response Payload

A success response shall contain the search results in an Acceptable Media Type. See Section 8.7.5.

A failure response payload may contain a Status Report describing any failures, warnings, or other useful information.

# A Collected ABNF

A machine readable collected ABNF for the syntax defined in this Part of the Standard can be found at ftp://medical.nema.org/medical/dicom/ABNF/part18_abnf.txt

# B Examples (Informative)

## B.1 Retrieving a Simple DICOM Image in JPEG

    http://www.hospital-stmarco/radiology/wado.php?requestType=WADO
      &studyUID=1.2.250.1.59.40211.12345678.678910
      &seriesUID=1.2.250.1.59.40211.789001276.14556172.67789
      &objectUID=1.2.250.1.59.40211.2678810.87991027.899772.2

## B.2 Retrieving a DICOM SR in HTML

    http://server234/script678.asp?requestType=WADO
      &studyUID=1.2.250.1.59.40211.12345678.678910
      &seriesUID=1.2.250.1.59.40211.789001276.14556172.67789
      &objectUID=1.2.250.1.59.40211.2678810.87991027.899772.2
      &charset=UTF-8

## B.3 Retrieving a Region of A DICOM Image

Retrieving a region of a DICOM image, converted if possible in JPEG2000, with annotations burned into the image containing the patient name and technical information, and mapped into a defined image size:

    https://aspradio/imageaccess.js?requestType=WADO
      &studyUID=1.2.250.1.59.40211.12345678.678910
      &seriesUID=1.2.250.1.59.40211.789001276.14556172.67789
      &objectUID=1.2.250.1.59.40211.2678810.87991027.899772.2
      &contentType=image%2Fjp2;level=1,image%2Fjpeg;q=0.5
      &annotation=patient,technique
      &columns=400
      &rows=300
      &region=0.3,0.4,0.5,0.5
      &windowCenter=-1000
      &windowWidth=2500

## B.4 Retrieving As A DICOM Media Type

Retrieving a DICOM image object using the baseline 8-bit lossy JPEG transfer syntax, and de-identified:

    http://www.medical-webservice.st/RetrieveDocument?requestType=WADO
      &studyUID=1.2.250.1.59.40211.12345678.678910
      &seriesUID=1.2.250.1.59.40211.789001276.14556172.67789
      &objectUID=1.2.250.1.59.40211.2678810.87991027.899772.2
      &contentType=application%2Fdicom
      &anonymize=yes
      &transferSyntax=1.2.840.10008.1.2.4.50

# C Retired

See PS3.18-2019a.

# D IANA Character Set Mapping

Table D-1 provides a mapping of some IANA Character Set Registry Preferred MIME Names to DICOM Specific Character Set Defined Terms.

Table D-1. IANA Character Set Mapping

IANA Preferred MIME Name | DICOM Defined Terms for Specific Character Set (0008,0005) | Language
--- | --- | ---
ISO-8859-1 | ISO_IR 100 | Latin-1 Latin alphabet
ISO-8859-2 | ISO_IR 101 | Latin-2 Eastern European
ISO-8859-3 | ISO_IR 109 | Latin alphabet #3
ISO-8859-4 | ISO_IR 110 | Latin alphabet #4
ISO-8859-5 | ISO_IR 144 | Cyrillic
ISO-8859-6 | ISO_IR 127 | Arabic
ISO-8859-7 | ISO_IR 126 | Greek
ISO-8859-8 | ISO_IR 138 | Hebrew
ISO-8859-9 | ISO_IR 148 | Latin alphabet #5
TIS-620 | ISO_IR 166 | Thai
ISO-2022-JP | ISO 2022 IR 13\ISO 2022 IR 87 | Japanese
ISO-2022-KR | ISO 2022 IR 6\ISO 2022 IR 149 | Korean
ISO-2022-CN | ISO 2022 IR 6\ISO 2022 IR 58 | Chinese
GB18030 | GB18030 | Chinese
GBK | GBK | Chinese
UTF-8 | ISO_IR 192 | Unicode

# E Retired

See PS3.18-2019a.

# F DICOM JSON Model

## F.1 Introduction to JavaScript Object Notation (JSON)

JSON is a text-based open standard, derived from JavaScript, for representing data structures and associated arrays. It is language-independent, and primarily used for serializing and transmitting lightweight structured data over a network connection. It is described in detail by the Internet Engineering Task Force (IETF) in [RFC4627], available at http://www.ietf.org/rfc/rfc4627.txt.

The DICOM JSON Model complements the XML-based Native DICOM Model, by providing a lightweight representation of data returned by DICOM web services. While this representation can be used to encode any type of DICOM Data Set it is expected to be used by client applications, especially mobile clients, such as described in the QIDO-RS use cases (see Annex HHH “Transition from WADO to RESTful Services (Informative)” in PS3.17).

## F.2 DICOM JSON Model

The DICOM JSON Model follows the Native DICOM Model for XML very closely, so that systems can take advantage of both formats without much retooling. The Media Type for DICOM JSON is application/dicom+json. The default character repertoire shall be UTF-8 / ISO_IR 192.

### F.2.1 Multiple Results Structure

Multiple results returned in JSON are organized as a single top-level array of JSON objects. This differs from the Native DICOM Model, which returns multiple results as a multi-part collection of singular XML documents.

#### F.2.1.1 Examples

##### F.2.1.1.1 Native DICOM Model

    <?xml version="1.0" encoding="UTF-8" xml:space="preserve" ?>
    <NativeDicomModel>
      <DicomAttribute tag="0020000D" vr="UI" keyword="StudyInstanceUID">
        <Value number="1">1.2.392.200036.9116.2.2.2.1762893313.1029997326.945873</Value>
      </DicomAttribute>
    </NativeDicomModel>
    …
    <?xml version="1.0" encoding="UTF-8" xml:space="preserve" ?>
    <NativeDicomModel>
      <DicomAttribute tag="0020000D" vr="UI" keyword="StudyInstanceUID">
        <Value number="1">1.2.444.200036.9116.2.2.2.1762893313.1029997326.945876</Value>
      </DicomAttribute>
    </NativeDicomModel>

##### F.2.1.1.2 DICOM JSON Model

    [
      {
         "0020000D": {
          "vr": "UI",
          "Value": [ "1.2.392.200036.9116.2.2.2.1762893313.1029997326.945873" ]
        }
      },
      {
        "0020000D" : {
          "vr": "UI",
          "Value": [ "1.2.392.200036.9116.2.2.2.2162893313.1029997326.945876" ]
        }
      }
    ]

### F.2.2 DICOM JSON Model Object Structure

The DICOM JSON Model object is a representation of a DICOM Data Set.

The internal structure of the DICOM JSON Model object is a sequence of objects representing attributes within the DICOM Data Set.

Attribute objects within a DICOM JSON Model object must be ordered by their property name in ascending order.

Group Length (gggg,0000) attributes shall not be included in a DICOM JSON Model object.

The name of each attribute object is:

- The eight character uppercase hexadecimal representation of a DICOM Tag

Each attribute object contains the following named child objects:

- vr: A string encoding the DICOM Value Representation. The mapping between DICOM Value Representations and JSON Value Representations is described in Section F.2.3.

- At most one of:

  - Value: An array containing one of:

    - The Value Field elements of a DICOM attribute with a VR other than PN, SQ, OB, OD, OF, OL, OW, or UN (described in Section F.2.4)

      The encoding of empty Value Field elements is described in Section F.2.5

    - The Value Field elements of a DICOM attribute with a VR of PN. The non-empty name components of each element are encoded as a JSON strings with the following names:

      - Alphabetic

      - Ideographic

      - Phonetic

    - JSON DICOM Model objects corresponding to the sequence items of an attribute with a VR of SQ

      Empty sequence items are represented by empty objects

  - BulkDataURI: A string encoding the WADO-RS URL of a bulk data item describing the Value Field of an enclosing Attribute with a VR of DS, FL, FD, IS, LT, OB, OD, OF, OL, OW, SL, SS, ST, UC, UL, UN, US, or UT (described in Section F.2.6)

  - InlineBinary: A base64 string encoding the Value Field of an enclosing Attribute with a VR of OB, OD, OF, OL, OW, or UN (described in Section F.2.7)

### Note

1. For Private Data Elements, the group and element numbers will follow the rules specified in Section 7.8.1 in PS3.5

2. The person name representation is more closely aligned with the DICOM Data Element representation than the DICOM PS3.19 XML representation.

### F.2.3 DICOM JSON Value Representation

The value representation (VR) is included in each DICOM JSON Model attribute object and named "vr". For example:

    "vr": "CS"

All DICOM Value Representations are mapped to specified JSON Data Types (see Table F.2.3-1). The JSON encodings shall conform to the Definition, Character Repertoire (if applicable) and Length of Value specified for that Value Representation (see Section 6.2 “Value Representation (VR)” in PS3.5 ) with the following exceptions:

- Attributes with a Value Representation of AT shall be restricted to eight character uppercase hexadecimal representation of a DICOM Tag

Table F.2.3-1. DICOM VR to JSON Data Type Mapping

VR Name | Type | JSON Data Type
--- | --- | ---
AE | Application Entity | String
AS | Age String | String
AT | Attribute Tag | String
CS | Code String | String
DA | Date | String
DS | Decimal String | Number
DT | Date Time | String
FL | Floating Point Single | Number
FD | Floating Point Double | Number
IS | Integer String | Number
LO | Long String | String
LT | Long Text | String
OB | Other Byte | Base64 encoded octet-stream
OD | Other Double | Base64 encoded octet-stream
OF | Other Float | Base64 encoded octet-stream
OL | Other Long | Base64 encoded octet-stream
OW | Other Word | Base64 encoded octet-stream
PN | Person Name | Object containing Person Name component groups as strings (see Section F.2.2)
SH | Short String | String
SL | Signed Long | Number
SQ | Sequence of Items | Array containing DICOM JSON Objects
SS | Signed Short | Number
ST | Short Text | String
TM | Time | String
UC | Unlimited Characters | String
UI | Unique Identifier (UID) | String
UL | Unsigned Long | Number
UN | Unknown | Base64 encoded octet-stream
UR | Universal Resource Identifier or Universal Resource Locator (URI/URL) | String
US | Unsigned Short | Number
UT | Unlimited Text | String

Although data, such as dates, are represented in the DICOM JSON model as strings, it is expected that they will be treated in the same manner as the original attribute as defined by Chapter 6 in PS3.6 .

### F.2.4 DICOM JSON Value Multiplicity

The value or values of a given DICOM attribute are given in the "Value" array. The value multiplicity (VM) is not contained in the DICOM JSON object.

For example:

    "Value": [ "bar", "foo" ]

or:

    "Value": [ "bar" ]

### F.2.5 DICOM JSON Model Null Values

If an attribute is present in DICOM but empty (i.e., Value Length is 0), it shall be preserved in the DICOM JSON attribute object containing no "Value", "BulkDataURI" or "InlineBinary".

If a multi-valued attribute has one or more empty values these are represented as "null" array elements. For example:

    "Value": [ "bar", null, "foo" ]

If a sequence contains empty items these are represented as empty JSON object in the array.

    "Value": [ { … }, { }, { … } ]

### F.2.6 BulkDataURI

If an attribute contains a "BulkDataURI" , this contains the URI of a bulk data element as defined in Table A.1.5-2 in PS3.19 .

### F.2.7 InlineBinary

If an attribute contains an "InlineBinary", this contains the base64 encoding of the enclosing attribute's Value Field.

There is a single InlineBinary value representing the entire Value Field, and not one per Value in the case where the Value Multiplicity is greater than one. E.g., a LUT with 4096 16 bit entries that may be encoded in DICOM with a Value Representation of OW, with a VL of 8192 and a VM of 1, or a US VR with a VL of 8192 and a VM of 4096 would both be represented as a single InlineBinary string.

All rules (e.g., byte ordering and swapping) in DICOM PS3.5 apply.

### Note

Implementers should in particular pay attention to the PS3.5 rules regarding the value representations of OD, OF, OL and OW.

## F.3 Transformation with other DICOM Formats

### F.3.1 Native DICOM Model XML

The transformation between the Native DICOM Model XML and the DICOM JSON model cannot be done through the use of generic XML - JSON converters.

The mapping between the two formats is as follows (see also Table F.3.1-1):

- The XML "NativeDicomModel" element maps to the DICOM JSON Model Object

- Each "DicomAttribute" element maps to an attribute object within the DICOM JSON model object

  - The "tag" attribute maps to the JSON object name

    - The Native DICOM Model XML allows for duplicate Tag values and the DICOM JSON model does not. To resolve this, private attribute Tag values must be remapped according to the conflict avoidance rules specified in Section 7.8.1 “Private Data Element Tags” in PS3.5 .

  - The "vr" attribute maps to the "vr" child string

- "Value" elements map to members of the "Value" child array

  - A "Value" element with the attribute "number=n" maps to "Value[n-1]"

  - Empty "Value" elements are represented by "null" entries in the "Value" array

- "PersonName" elements map to objects within the "Value" array. For a "PersonName" element with the attribute "number=n":

  - The "Alphabetic" element maps to "Value[ n-1 ].Alphabetic"

  - The "Ideographic" element maps to "PersonName[ n ].Ideographic"

  - The "Phonetic" element maps to "PersonName[ n ].Phonetic"

- "Item" elements map to members of the "Value" child array

  - An "Item" element with the attribute "number=n" maps to "Value[n-1]"

  - Empty "Item" elements are represented by empty JSON property entries in the "Value" array

- The "uri" attribute of the "BulkData" element maps to the "BulkDataURI" string

- The "InlineBinary" element maps to the "InlineBinary" string

Table F.3.1-1. XML to JSON Mapping

DICOM PS3.19 XML | DICOM JSON Model
--- | ---
`<NativeDicomModel>` `<DicomAttribute tag=` `ggggee01` `… />` `<DicomAttribute tag=` `ggggee02` `… />` `…` `</NativeDicomModel>` | `{` `ggggee01` `: { … },` `ggggee02` `: { … },` `…` `}`
`<DicomAttribute` `tag=` `ggggeeee` `vr=` `VR` `>` `<Value number="1">` `Value` `</Value>` `</DicomAttribute>` | `ggggeeee` `: {` `"vr":` `VR` `,` `"Value": [` `Value` `]` `}`
`<DicomAttribute tag=` `ggggeeee` `… >` `<Value number="1">` `Value1` `</Value>` `<Value number="2">` `Value2` `</Value>` `…` `</DicomAttribute>` | `ggggeeee` `: {` `…` `"Value": [` `Value1` `,` `Value2` `, …` `]` `}`
`<DicomAttribute tag=` `ggggeeee` `… >` `</DicomAttribute>` | `ggggeeee` `: {` `…` `}`
`<DicomAttribute tag=` `ggggeeee` `vr="PN" … >` `<PersonName number="1">` `<Alphabetic>` `<FamilyName>` `SB1` `</FamilyName>` `<GivenName>` `SB2` `</GivenName>` `<MiddleName>` `SB3` `</MiddleName>` `<NamePrefix>` `SB4` `</NamePrefix>` `<NameSuffix>` `SB5` `</NameSuffix>` `</Alphabetic>` `<Ideographic>` `<FamilyName>` `ID1` `</FamilyName>` `…` `</Ideographic>` `<Phonetic>` `<FamilyName>` `PH1` `</FamilyName>` `…` `</Phonetic>` `</PersonName>` `<PersonName number="2">` `<Alphabetic>` `<FamilyName>` `SB6` `</FamilyName>` `</Alphabetic>` `</PersonName>` `</DicomAttribute>` | `ggggeeee` `: {` `…` `"vr": "PN",` `"Value": [` `{` `"` `Alphabetic` `"` `:` `"SB1^SB2^SB3^SB4^SB5",` `"Ideographic":` `"ID1^ID2^ID3^ID4^ID5"` `,` `"Phonetic":` `"PH1^PH2^PH3^PH4^PH5"` `},` `{` `"Alphabetic":` `"` `SB6` `"` `}` `]` `}`
`<DicomAttribute tag=` `ggggeeee` `vr="SQ" … >` `<Item number="1">` `<DicomAttribute tag=` `ggggee01` `… />` `<DicomAttribute tag=` `ggggee02` `… />` `…` `</Item>` `<Item number="2">` `<DicomAttribute tag=` `ggggee01` `… />` `<DicomAttribute tag=` `ggggee02` `… />` `…` `</Item>` `<Item number="3">` `</Item>` `…` `</DicomAttribute>` | `ggggeeee` `: {` `…` `"vr": "SQ",` `"Value":` `[` `{` `ggggee01` `: { … },` `ggggee02` `: { … },` `…` `}` `{` `ggggee01` `: { … },` `ggggee02` `: { … },` `…` `}` `{ }` `…` `]` `}`
`<DicomAttribute tag=` `ggggeeee` `… >` `<BulkData URI=` `BulkDataURI` `>` `</DicomAttribute>` | `ggggeeee` `: {` `…` `"BulkDataURI":` `BulkDataURI` `}`
`<DicomAttribute tag=` `ggggeeee` `… >` `<InlineBinary>` `Base64String` `</InlineBinary>` `</DicomAttribute>` | `ggggeeee` `: {` `…` `"InlineBinary": "` `Base64String"` `}`
`<DicomAttribute tag=` `gggg00ee` `PrivateCreator=` `PrivateCreator` `… >` `…` `</DicomAttribute>` | `ggggXXee` `: {` `…` `}`

## F.4 DICOM JSON Model Example

    // The following example is a QIDO-RS SearchForStudies response consisting
    // of two matching studies, corresponding to the example QIDO-RS request:
    // GET http://qido.nema.org/studies?PatientID=12345&includefield=all&limit=2
    [
        {   // Result 1
            "00080005": {
                "vr": "CS",
                "Value": [ "ISO_IR 192" ]
            },
            "00080020": {
                "vr": "DT",
                "Value": [ "20130409" ]
            },
            "00080030": {
                "vr": "TM",
                "Value": [ "131600.0000" ]
            },
            "00080050": {
                "vr": "SH",
                "Value": [ "11235813" ]
            },
            "00080056": {
                "vr": "CS",
                "Value": [ "ONLINE" ]
            },
            "00080061": {
                "vr": "CS",
                "Value": [
                    "CT",
                    "PET"
                ]
            },
            "00080090": {
                "vr": "PN",
                "Value": [
                  {
                    "Alphabetic": "^Bob^^Dr."
                  }
                ]
            },
            "00081190": {
                "vr": "UR",
                "Value": [ "http://wado.nema.org/studies/
                1.2.392.200036.9116.2.2.2.1762893313.1029997326.945873" ]
            },
            "00090010": {
                "vr": "LO",
                "Value": [ "Vendor A" ]
            },
            "00091002": {
                "vr": "UN",
                "InlineBinary": [ "z0x9c8v7" ]
            },
            "00100010": {
                "vr": "PN",
                "Value": [
                  {
                    "Alphabetic": "Wang^XiaoDong",
                    "Ideographic": "王^小東"
                  }
                ]
            },
            "00100020": {
                "vr": "LO",
                "Value": [ "12345" ]
            },
            "00100021": {
                "vr": "LO",
                "Value": [ "Hospital A" ]
            },
            "00100030": {
                "vr": "DT",
                "Value": [ "19670701" ]
            },
            "00100040": {
                "vr": "CS",
                "Value": [ "M" ]
            },
            "00101002": {
                "vr": "SQ",
                "Value": [
                    {
                        "00100020": {
                            "vr": "LO",
                            "Value": [ "54321" ]
                        },
                        "00100021": {
                            "vr": "LO",
                            "Value": [ "Hospital B" ]
                        }
                    },
                    {
                        "00100020": {
                            "vr": "LO",
                            "Value": [ "24680" ]
                        },
                        "00100021": {
                            "vr": "LO",
                            "Value": [ "Hospital C" ]
                        }
                    }
                ]
            },
            "0020000D": {
                "vr": "UI",
                "Value": [ "1.2.392.200036.9116.2.2.2.1762893313.1029997326.945873" ]
            },
            "00200010": {
                "vr": "SH",
                "Value": [ "11235813" ]
            },
            "00201206": {
                "vr": "IS",
                "Value": [ 4 ]
            },
            "00201208": {
                "vr": "IS",
                "Value": [ 942 ]
            }
        },
        {   // Result 2
            "00080005": {
                "vr": "CS",
                "Value": [ "ISO_IR 192" ]
            },
            "00080020": {
                "vr": "DT",
                "Value": [ "20130309" ]
            },
            "00080030": {
                "vr": "TM",
                "Value": [ "111900.0000" ]
            },
            "00080050": {
                "vr": "SH",
                "Value": [ "11235821" ]
            },
            "00080056": {
                "vr": "CS",
                "Value": [ "ONLINE" ]
            },
            "00080061": {
                "vr": "CS",
                "Value": [
                    "CT",
                    "PET"
                ]
            },
            "00080090": {
                "vr": "PN",
                "Value": [
                  {
                    "Alphabetic": "^Bob^^Dr."
                  }
                ]
            },
            "00081190": {
                "vr": "UR",
                "Value": [ "http://wado.nema.org/studies/
                1.2.392.200036.9116.2.2.2.2162893313.1029997326.945876" ]
            },
            "00090010": {
                "vr": "LO",
                "Value": [ "Vendor A" ]
            },
            "00091002": {
                "vr": "UN",
                "InlineBinary": [ "z0x9c8v7" ]
            },
            "00100010": {
                "vr": "PN",
                "Value": [
                  {
                    "Alphabetic": "Wang^XiaoDong",
                    "Ideographic": "王^小東"
                  }
                ]
            },
            "00100020": {
                "vr": "LO",
                "Value": [ "12345" ]
            },
            "00100021": {
                "vr": "LO",
                "Value": [ "Hospital A" ]
            },
            "00100030": {
                "vr": "DT",
                "Value": [ "19670701" ]
            },
            "00100040": {
                "vr": "CS",
                "Value": [ "M" ]
            },
            "00101002": {
                "vr": "SQ",
                "Value": [
                    {
                        "00100020": {
                            "vr": "LO",
                            "Value": [ "54321" ]
                        },
                        "00100021": {
                            "vr": "LO",
                            "Value": [ "Hospital B" ]
                        }
                    },
                    {
                        "00100020": {
                            "vr": "LO",
                            "Value": [ "24680" ]
                        },
                        "00100021": {
                            "vr": "LO",
                            "Value": [ "Hospital C" ]
                        }
                    }
                ]
            },
            "0020000D": {
                "vr": "UI",
                "Value": [ "1.2.392.200036.9116.2.2.2.2162893313.1029997326.945876" ]
            },
            "00200010": {
                "vr": "SH",
                "Value": [ "11235821" ]
            },
            "00201206": {
                "vr": "IS",
                "Value": [ 5 ]
            },
            "00201208": {
                "vr": "IS",
                "Value": [ 1123 ]
            }
        }
    ]

## F.5 Retired

See PS3.18-2019a.

# G WADL JSON Representation

## G.1 Introduction

While the WADL specification only specifies an XML encoding for the WADL payload, the data structure can easily be represented using JSON. Additionally, conversion from XML to JSON and vice-versa can be done in a lossless manner.

## G.2 XML Elements

The JSON encoding of WADL XML elements depends on whether the element is:

- a "doc" element

- an element that is unique within a particular parent element (e.g., "request")

- an element that can be repeated within a particular parent element (e.g., "param")

### G.2.1 Doc Elements

A "doc" element is represented as an array of objects, where each object may contain:

- a "@xml:lang" string

- a "@title" string

- a "value" string

Example:

    "doc": [
    		{
    			"@xml:lang": "en",
    			"value": "Granular cell tumor"
    		},
    		{
    			"@xml:lang": "ja",
    			"value": "顆粒細胞腫"
    		},
    		{
    			"@xml:lang": "fr",
    			"value": "Tumeur à cellules granuleuses"
    		}
    ]

### G.2.2 Unique Elements

All unique WADL XML elements are represented as an object whose name is the name of the XML element and where each member may contain:

- a "@{attribute}" string for each XML attribute of the name {attribute}

- a child object for each child element that must be unique

- a child array for each child element that may not be unique

Example:

    "request": {
    			"param": [ ... ],
    			"representation": [ ... ]
    }

### G.2.3 Repeatable Elements

All repeatable WADL XML elements are represented as an array of objects whose name is the name of the XML element and where each may contain:

- a "@{attribute}" string for each XML attribute of the name {attribute}

- a child object for each child element that must be unique

- a child array for each child element that may not be unique

Example:

    "param": [
    		{
    			"@name": "Accept",
    			"@style": "header"
    		},
    		{
    			"@name": "Cache-control",
    			"@style": "header"
    		}
    	]

# H Capabilities Description

A Capabilities Description is a WADL Document. See [WADL].

The Capabilities Description resource follows directly and unambiguously from the RESTful resources defined in Chapter 10, Chapter 11 and Chapter 12.

The WADL document shall contain one top-level "application" element.

The "application" element shall contain one "resources" element whose "base" attribute value is the base URL for the service. This may be a combination of protocol (either http or https), host, port, and application.

Additionally, the WADL content shall include a "resource" element for the Target Resource specified in the request describing all methods and child resources for the specified resource and each of its children.

The full resource tree and the methods defined for each resource are described in Table H-1.

### Note

The Retrieve Capabilities Transaction is excluded from Table H-1 because that transaction is used to retrieve this document and WADL is not self-describing.

Table H-1. Resources and Methods

Service | Resource | Transactions | Reference
--- | --- | --- | ---
Studies (see Section 10.1.1)
| studies | Search for Studies Store Instances | Section 10.6 Section 10.5
{StudyInstance} | Retrieve Study Store Study Instances | Section 10.4 Section 10.5
metadata | Retrieve Study Metadata | Section 10.4
series | Search for Study Series | Section 10.6
{SeriesInstance} | Retrieve Series | Section 10.4
metadata | Retrieve Series Metadata | Section 10.4
instances | Search for Study Series Instances | Section 10.4
{SOPInstance} | Retrieve Instance | Section 10.4
metadata | Retrieve Instance Metadata | Section 10.4
frames | N/A | N/A
{framelist} | Retrieve Frames | Section 10.4
instances | Search for Study Instances | Section 10.6
series | Search for Series | Section 10.6
{SeriesInstance} | N/A | N/A
{instances} | Search for Instances | Section 10.6
instances | Search for Instances | Section 10.6
{BulkDataReference} | Retrieve Bulkdata | Section 10.4
Worklist (see Section 11.1.1)
| workitems | Search for Workitem Create Workitem | Section 11.9 Section 11.4
{Workitem} | Retrieve Workitem Update Workitem | Section 11.4 Section 11.6
state | Change Workitem State | Section 11.7
cancelrequest | Request Workitem Cancellation | Section 11.8
subscribers | N/A | N/A
{AETitle} | Subscribe Unsubscribe | Section 11.10 Section 11.11
1.2.840.10008.5.1.4.34.5 | N/A | N/A
subscribers | N/A | N/A
{AETitle} | Subscribe Unsubscribe | Section 11.10 Section 11.11
suspend | Unsubscribe | Section 11.11
1.2.840.10008.5.1.4.34.5.1 | N/A | N/A
subscribers | N/A | N/A
{AETitle} | Subscribe Unsubscribe | Section 11.10 Section 11.11
suspend | Suspend Worklist Subscription | Section 11.11
Non-Patient Instances (see Section 12.1.1)
| color-palettes | N/A | N/A
{uid} | Retrieve Store Search | Section 12.4 Section 12.5 Section 12.6
defined-procedure-protocol | N/A | N/A
{uid} | Retrieve Store Search | Section 12.4 Section 12.5 Section 12.6
hanging-protocol | N/A | N/A
{uid} | Retrieve Store Search | Section 12.4 Section 12.5 Section 12.6
implant-templates | N/A | N/A
{uid} | Retrieve Store Search | Section 12.4 Section 12.5 Section 12.6

# I Store Instances Response Module

## I.1 Response Message Body

Table I.1-1 defines the Attributes for referencing SOP Instances that are contained in a Store Instances Response Module in the response message body.

Table I.1-1. Store Instances Response Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Retrieve URL | (0008,1190) | 2 | The URL where the Study is available for retrieval via a Studies Retrieve Transaction (Section 10.4). ### Note The VR of this attribute has changed from UT to UR.
Failed SOP Sequence | (0008,1198) | 1C | A Sequence of Items where each Item references a single SOP Instance for which storage could not be provided. Required if one or more SOP Instances failed to store.
>Table 10-11 “SOP Instance Reference Macro Attributes” in PS3.3
>Failure Reason | (0008,1197) | 1 | The reason that storage could not be provided for this SOP Instance. See Section I.2.2.
Referenced SOP Sequence | (0008,1199) | 1C | A Sequence of Items where each Item references a single SOP Instance that was successfully stored. Required if one or more SOP Instances were successfully stored.
>Table 10-11 “SOP Instance Reference Macro Attributes” in PS3.3
>Retrieve URL | (0008,1190) | 2 | The URL where the SOP Instance is available for retrieval via a Studies Retrieve Transaction (Section 10.4). ### Note The VR of this attribute has changed from UT to UR.
>Warning Reason | (0008,1196) | 1C | The reason that this SOP Instance was accepted with warnings. Required if there was a warning for this SOP Instance. See Section I.2.1.
>Original Attributes Sequence | (0400,0561) | 3 | Sequence of Items containing all attributes that were removed or replaced by other values. One or more Items are permitted in this sequence.
>>Attribute Modification DateTime | (0400,0562) | 1 | Date and time the attributes were removed and/or replaced.
>>Modifying System | (0400,0563) | 1 | Identification of the system that removed and/or replaced the attributes.
>>Reason for the Attribute Modification | (0400,0565) | 1 | Reason for the attribute modification. Defined Terms COERCE Replace values of attributes such as Patient Name, ID, Accession Number, for example, during import of media from an external institution, or reconciliation against a master patient index. CORRECT Replace incorrect values, such as Patient Name or ID, for example, when incorrect worklist item was chosen or operator input error.
>>Modified Attributes Sequence | (0400,0550) | 1 | Sequence that contains all the Attributes, with their previous values, that were modified or removed from the main Data Set. Only a single Item shall be included in this sequence.
>>Any Attribute from the main Data Set that was modified or removed; may include Sequence Attributes and their Items.
Other Failures Sequence | (0008,119A) | 1C | Reasons not associated with a specific SOP Instance that storage could not be provided. Each Item references a single storage failure. Required if there are one or more failures not associated with a specific SOP Instance.
>Failure Reason | (0008,1197) | 1 | The reason that storage could not be provided for this message item. See Section I.2.2.

## I.2 Store Instances Response Attribute Description

### I.2.1 Warning Reason

Table I.2-1 defines the semantics for which the associated value shall be used for the Warning Reason (0008,1196):

Table I.2-1. Store Instances Response Warning Reason Values

Status Code (hexadecimal) | Status Code (decimal) | Meaning | Explanation
--- | --- | --- | ---
B000 | 45056 | Coercion of Data Elements | The Studies Store Transaction (Section 10.5) modified one or more data elements during storage of the instance. See Section 10.5.3.
B006 | 45062 | Elements Discarded | The Studies Store Transaction (Section 10.5) discarded some data elements during storage of the instance. See Section 10.5.3.
B007 | 45063 | Data Set does not match SOP Class | The Studies Store Transaction (Section 10.5) observed that the Data Set did not match the constraints of the SOP Class during storage of the instance.

Additional codes may be used for the Warning Reason (0008,1196) to address the semantics of other issues.

In the event that multiple codes may apply, the single most appropriate code shall be used.

### I.2.2 Failure Reason

Table I.2-2 defines the semantics for which the associated value shall be used for the Failure Reason (0008,1197). Implementation specific warning and error codes shall be defined in the conformance statement:

Table I.2-2. Store Instances Response Failure Reason Values

Status Code (hexadecimal) | Status Code (decimal) | Meaning | Explanation
--- | --- | --- | ---
A7xx | 42752 - 43007 | Refused out of Resources | The Studies Store Transaction (Section 10.5) did not store the instance because it was out of resources.
A9xx | 43264 - 43519 | Error: Data Set does not match SOP Class | The Studies Store Transaction (Section 10.5) did not store the instance because the instance does not conform to its specified SOP Class.
Cxxx | 49152 - 53247 | Error: Cannot understand | The Studies Store Transaction (Section 10.5) did not store the instance because it cannot understand certain Data Elements.
C122 | 49442 | Referenced Transfer Syntax not supported | The Studies Store Transaction (Section 10.5) did not store the instance because it does not support the requested Transfer Syntax for the instance.
0110 | 272 | Processing failure | The Studies Store Transaction (Section 10.5) did not store the instance because of a general failure in processing the operation.
0122 | 290 | Referenced SOP Class not supported | The Studies Store Transaction (Section 10.5) did not store the instance because it does not support the requested SOP Class.

Additional codes may be used for the Failure Reason (0008,1197) to address the semantics of other issues.

In the event that multiple codes may apply, the single most appropriate code shall be used.

## I.3 Response Message Body Example

The following is an example of a PS3.18 XML Store Instances Response Module in the response message body containing 2 failed SOP Instances, 1 successful SOP Instance, and 1 accepted SOP Instance with a warning:

    <?xml version="1.0" encoding="utf-8" xml:space="preserve"?>
    <NativeDicomModel xmlns="http://dicom.nema.org/PS3.19/models/NativeDICOM"
    xsi:schemaLocation="http://dicom.nema.org/PS3.19/models/NativeDICOM"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <DicomAttribute tag="00081198" vr="SQ" keyword="FailedSOPSequence">
        <Item number="1">
          <DicomAttribute tag="00081150" vr="UI" keyword="ReferencedSOPClassUID">
            <Value number="1">1.2.840.10008.3.1.2.3.1</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081155" vr="UI"
          keyword="ReferencedSOPInstanceUID">
            <Value number="1">
            2.16.124.113543.6003.1011758472.49886.19426.2085542308</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081197" vr="US" keyword="FailureReason">
            <Value number="1">290</Value>
          </DicomAttribute>
        </Item>
        <Item number="2">
          <DicomAttribute tag="00081150" vr="UI" keyword="ReferencedSOPClassUID">
            <Value number="1">1.2.840.10008.3.1.2.3.1</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081155" vr="UI"
          keyword="ReferencedSOPInstanceUID">
            <Value number="1">
            2.16.124.113543.6003.1011758472.49886.19426.2085542309</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081197" vr="US" keyword="FailureReason">
            <Value number="1">290</Value>
          </DicomAttribute>
        </Item>
      </DicomAttribute>
      <DicomAttribute tag="00081199" vr="SQ" keyword="ReferencedSOPSequence">
        <Item number="1">
          <DicomAttribute tag="00081150" vr="UI" keyword="ReferencedSOPClassUID">
            <Value number="1">1.2.840.10008.5.1.4.1.1.2</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081155" vr="UI"
          keyword="ReferencedSOPInstanceUID">
            <Value number="1">
            2.16.124.113543.6003.189642796.63084.16748.2599092903</Value>
          </DicomAttribute>
          <DicomAttribute tag="00081190" vr="UR" keyword="RetrieveURL">
            <Value number="1">
            https://wadors.hospital.com/studies/2.16.124.113543.6003.1154777499.30246.19789.3503430045/
            series/2.16.124.113543.6003.2588828330.45298.17418.2723805630/
            instances/2.16.124.113543.6003.189642796.63084.16748.2599092903</Value>
          </DicomAttribute>
        </Item>
        <Item number="2">
          <DicomAttribute tag="00081150" vr="UI" keyword="ReferencedSOPClassUID">
            <Value number="1">1.2.840.10008.5.1.4.1.1.2</Value>
          </DicomAttribute>
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