C.7.6.16.2.17 Respiratory Synchronization Macro

Table C.7.6.16-18 specifies the attributes of the Respiratory Synchronization Functional Group macro.

Table C.7.6.16-18RESPIRATORY SYNCHRONIZATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Respiratory Synchronization Sequence (0020,9253) 1 Sequence that describes the frame specific respiratory synchronization parameters. Only a single Item shall be included in this sequence.
>Respiratory Interval Time (0020,9254) 1C Measured interval time in ms from maximum respiration peak to the next peak for the respiratory cycle in which this frame occurs. See C.7.6.16.2.17.1 for further explanation. Required if Respiratory Motion Compensation Technique (0018,9170) equals other than NONE or REALTIME and Respiratory Trigger Type (0020,9250) is absent or has a value of TIME or BOTH.
>Nominal Percentage of Respiratory Phase (0020,9245) 1C The nominal time relative to the preceding respiratory inspiration maximum divided by the nominal respiratory interval multiplied by 100. Required if used as a dimension index, may be present otherwise.
>Nominal Respiratory Trigger Delay Time (0020,9255) 1 The nominal time in ms from the beginning of the respiratory interval to the value of the Frame Reference DateTime (0018,9151). See C.7.6.16.2.17.1 for further explanation.
>Actual Respiratory Trigger Delay Time (0020,9257) 1C The actual time in ms from the beginning of the respiratory interval to the value of the Frame Reference DateTime (0018,9151). See C.7.6.16.2.17.1 for further explanation. Required if Respiratory Trigger Type (0020,9250) is TIME or BOTH.
>Starting Respiratory Amplitude (0020,9246) 1C Nominal amplitude of the respiratory signal at which the acquisition of data for this frame begins, in percent of the nominal maximum value (which represents maximum inspiration). Required if Respiratory Trigger Type (0020,9250) is AMPLITUDE or BOTH.
>Starting Respiratory Phase (0020,9247) 1C The phase of respiration at which the Starting Respiratory Amplitude (0020,9246) was measured. Enumerated Value: INSPIRATION MAXIMUM EXPIRATION MINIMUM Required if Starting Respiratory Amplitude (0020,9246) is present.
>Ending Respiratory Amplitude (0020,9248) 1C Nominal amplitude of the respiratory signal at which the acquisition of data for this frame ends, in percent of the nominal maximum value (which represents maximum inspiration). Required if Respiratory Trigger Type (0020,9250) is AMPLITUDE or BOTH.
>Ending Respiratory Phase (0020,9249) 1C The phase of respiration at which the Ending Respiratory Amplitude (0020,9248) was measured. Enumerated Value: INSPIRATION MAXIMUM EXPIRATION MINIMUM Required if Ending Respiratory Amplitude (0020,9248) is present.

C.7.6.16.2.17.1 Relationship of Respiratory Timing Attributes

For time based respiratory gating, the Nominal Respiratory Trigger Delay Time (0020,9255) is the prescribed trigger delay time in ms from the previous Respiratory-peak to the value of the Frame Reference DateTime (0018,9151). When frames are acquired with prospective gating, that is, the data acquisition actually begins in response to a timed delay from the Respiratory trigger, it may be that Actual Respiratory Trigger Delay Time (0020,9257) and the Nominal Respiratory Trigger Delay Time (0020,9255) have the same value.

However, when frames are the result of retrospective gating, that is, the data is continuously acquired and then later compared with a simultaneously acquired respiratory waveform and fitted into bins corresponding to nominal phases of the respiratory cycle, then Nominal Respiratory Trigger Delay Time (0020,9255) and the Actual Respiratory Trigger Delay Time (0020,9257) may have different values.

Figure C.7.6.16-9a and C.7.6.16-9b depict the usage.

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Figure C.7.6.16-9aRespiratory Timing Tags

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Figure C.7.6.16-9bRelationship of Respiratory Amplitude Attributes