DICOM PS3.17 2021d - Explanatory Information

FFF.2.3.3.3 Encoding Details (Current)
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##### FFF.2.3.3.3 Encoding Details

This section provides detailed recommendations of the key Attributes to address this particular scenario. The usage of the "Frame Pixel Shift" macro in a 'per frame' context is recommended. Only the usage of Mask Module and the Frame Pixel Shift Macro is further detailed.

Table FFF.2.3-6. Enhanced X-Ray Angiographic Image IOD Modules

IE | Module | PS3.3 Reference | Usage
--- | --- | --- | ---
Image | Mask | C.7.6.10 | Specifies the groups of mask-contrast pairs identified by a Subtraction Item ID.

Table FFF.2.3-7. Enhanced XA Image Functional Group Macros

Functional Group Macro | PS3.3 Reference | Usage
--- | --- | ---
Frame Pixel Shift | C.7.6.16.2.14 | Specifies the pixel shift associated with the Subtraction IDs.

###### FFF.2.3.3.3.1 Mask Module Recommendations

This module is recommended to specify the subtraction parameters. The number of Items depends on the number of Subtractions to be applied (see Section FFF.2.3.2).

Table FFF.2.3-8. Mask Module Recommendations

Attribute Name | Tag | Comment
--- | --- | ---
Recommended Viewing Mode | (0028,1090) | Recommended in this scenario, a value of "SUB" is used in this case.
Mask Subtraction Sequence | (0028,6100) | Recommended in this scenario. Item can be used to specify: A range of contrast frames is to be subtracted from a generated mask; A different set of pixel-shift pairs is to be applied to a range of contrast frames.

###### FFF.2.3.3.3.2 Frame Pixel Shift Macro Recommendations

The usage in this scenario is on a "per frame" context to allow individual pixel shift factors for each Subtraction Item ID.

The Subtraction Item ID specified in the Mask Subtraction Sequence (0028,6100) as well as in the Frame Pixel Shift Sequence (0028,9415) allows creating a relationship between the subtraction (mask and contrast frames) and a corresponding set of pixel shift values.

The Pixel Shift specified for a given frame in the Frame Pixel Shift Macro is the shift to be applied when this frame is subtracted to its associated mask for the given Subtraction Item ID.

Not all frames may have the same number of Items in the Frame Pixel Shift Macro, but all frames that are in the scope of a Subtraction Item ID and identified as "contrast" frames in the Mask module are recommended to have a Frame Pixel Shift Sequence item with the related Subtraction Item ID.

Table FFF.2.3-9. Frame Pixel Shift Macro Recommendations

Attribute Name | Tag | Comment
--- | --- | ---
Frame Pixel Shift Sequence | (0008,9415) | Recommended in this scenario. The number of Items may differ for each frame.

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DICOM PS3.17 2021d - Explanatory Information