FFF.2.2 Review

FFF.2.2.1 Variable Frame-rate acquisition with Skip Frames

This application case provides information on how X-Ray acquisitions with variable time between frames can be organized by groups of frames to be reviewed with individual group settings.

FFF. User Scenario

The image acquisition system performs complex acquisition protocols with groups of frames to be displayed at different frame rates and others to be skipped.

Allow frame-rates in viewing applications to be different than acquired rates.

FFF. Encoding Outline

The XA IOD provides only one group of frames between start and stop trim.

The Enhanced XA/XRF IOD allows encoding of multiple groups of frames (frame collections) with dedicated display parameters.

The Enhanced XA IOD provides an exact acquisition time for each frame.

FFF. Encoding details

This section provides detailed recommendations of the key attributes to address this particular scenario.


IE Module PS 3.3 Reference Usage
Image XA/XRF Multi-frame Presentation C.8.19.7 Specifies the groups of frames and their display parameters.

FFF. XA/XRF Multi-frame Presentation Module Recommendations

The usage of this module is recommended to encode the grouping of frames (one or more groups) for display purposes and the related parameters for each group.


Attribute Name Tag Comment
Preferred Playback Sequencing (0018,1244) Specifies the direction of the playback.
Frame Display Sequence (0008,9458) Specifies the details on how frames are grouped for display purposes.

FFF. Example

An example of a 4 position peripheral stepping acquisition with different frame-rates is provided. One group is only 2 Frames (e.g., due to fast contrast bolus) and will be skipped for display purposes.

The whole image is reviewed in looping mode:

Below are the encoded values of the key attributes of this example:

Preferred Playback Sequencing (0018,1244) = 0
Frame Display Sequence (0008,9458)
Item 1
>Start Trim (0008,2142) = 1
>Stop Trim (0008,2143) = 17
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Display Frame Rate in Float (0008,9459) = 4.0
Item 2
>Start Trim (0008,2142) = 18
>Stop Trim (0008,2143) = 25
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Display Frame Rate in Float (0008,9459) = 2.0
Item 3
>Start Trim (0008,2142) = 26
>Stop Trim (0008,2143) = 27
>Skip Frame Range Flag (0008,9460) = SKIP
>Recommended Display Frame Rate in Float (0008,9459) = 2.0
Item 4
>Start Trim (0008,2142) = 28
>Stop Trim (0008,2143) = 36
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Display Frame Rate in Float (0008,9459) = 1.5

Figure FFF.2.2-1Attributes of the example of the Variable Frame-rate acquisition with Skip Frames