FFF.2.1.1.3 Encoding details

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

FFF.2.1.1.3.1 Enhanced XA Image

Table FFF.2.1-1ENHANCED X-RAY ANGIOGRAPHIC IMAGE IOD MODULES

IE Module PS 3.3 Reference Usage
Series General Series C.7.3.1 The General Series Module Modality (0008,0060) attribute description in PS 3.3 enforces the storage of waveform and pixel data in different Series IE.
Frame of Reference Synchronization C.7.4.2 Specifies that the image acquisition is synchronized. Will have the same content as the General ECG SOP Instance.
Equipment General Equipment C.7.5.1 Same as in the General ECG SOP Instance.
Image Cardiac Synchronization C.7.6.18.1 Contains information of the type of relationship between the ECG waveform and the image.
Enhanced XA/XRF Image C.8.19.2 Contains UID references to the related General ECG SOP Instance.

Table FFF.2. 1- 2 ENHANCED XA IMAGE FUNCTIONAL GROUP MACROS

Functional Group Macro PS 3.3 Reference Usage
Frame Content C.7.6.16.2.2 Provides timing information to correlate each frame to the recorded ECG samples.
Cardiac Synchronization C.7.6.16.2.7 Provides time relationships between the angiographic frames and the cardiac cycle.

FFF.2.1.1.3.1.1 Synchronization Module Recommendations

The usage of this Module is recommended to encode a “synchronized time” condition.

The specialty of Synchronization Triggers is not part of this scenario.

Table FFF.2.1-3 SYNCHRONIZATION MODULE Recommendations

Attribute Name Tag Comment
Synchronization Frame of Reference UID (0020,0200) Same UID as in the related General ECG SOP Instance.
Synchronization Trigger (0018,106A) In this scenario with no external trigger signal, the value “NO TRIGGER” is used.
Acquisition Time Synchronized (0018,1800) The value “Y” is used in this scenario.

FFF.2.1.1.3.1.2 General Equipment Module Recommendations

The usage of this Module is recommended to assure that the image contains identical equipment identification information as the referenced General ECG SOP Instance.

FFF.2.1.1.3.1.3 Cardiac Synchronization Module Recommendations

The usage of this module is recommended to indicate that the ECG is not used to trig the X-Ray acquisition, rather to time relate the frames to the ECG signal.

Table FFF.2.1-4 CARDIAC SYNCHRONIZATION MODULE Recommendations

Attribute Name Tag Comment
Cardiac Synchronization Technique (0018,9037) The value “REAL TIME” is used in this scenario.
Cardiac Signal Source (0018,9085) In this scenario, the value “ECG” is used to indicate that the cardiac waveform is an electrocardiogram.

FFF.2.1.1.3.1.4 Enhanced XA/XRF Image Module Recommendations

The usage of this module is recommended to reference from the image object to the related General ECG SOP Instance that contains the ECG data recorded simultaneously.

Table FFF.2.1-5 ENHANCED XA/XRF IMAGE MODULE Recommendations

Attribute Name Tag Comment
Referenced Instance Sequence (0008,114A) Reference to “General ECG SOP Instance” acquired in conjunction with this image. Contains a single item.
>Referenced SOP Class UID (0008,1150) 1.2.840.10008.5.1.4.1.1.9.1.2” i.e. reference to an General ECG SOP Instance
>Referenced SOP Instance UID (0008,1155) Instance UID of referenced waveform
>Purpose of Reference Code Sequence (0040,A170) CID 7004 is used; identify clear reason for the Reference.

FFF.2.1.1.3.1.5 Cardiac Synchronization Macro Recommendations

If there is a specific ECG analysis that determines the time between the R-peaks and the angiographic frames, the usage of this macro is recommended.

As the frames are acquired at a frame rate independent of cardiac phases, this macro is used in a “per frame functional group” to encode the position of each frame relative to its prior R-peak.

FFF.2.1.1.3.1.6 Frame Content Macro Recommendations

In this scenario the timing information is important to correlate each frame to the recorded ECG.

If there is a specific ECG analysis, this macro allows the encoding of the position in the cardiac cycle that is most representative of each frame.

The following table gives recommendations for usage in this scenario.

Table FFF.2.1-6 FRAME CONTENT MACRO Recommendations

Attribute Name Tag Comment
Frame Content Sequence (0020,9111)
>Frame Reference Datetime (0018,9151) Exact Time taken from the internal clock.
>Frame Acquisition Datetime (0018,9074) Exact Time taken from the internal clock.
>Cardiac Cycle Position (0018,9236) Optional, if ECG analysis is available.

FFF.2.1.1.3.2 General ECG Object

This IOD will encode the recorded ECG waveform data, which is done by the image acquisition system. Since this is not a dedicated waveform modality device, appropriate defaults for most of the data have to be recommended to fulfill the requirements according to PS 3.3.

Table FFF.2. 1-7 General ECG IOD Modules

IE Module PS 3.3 Reference Usage
Series General Series C.7.3.1 The General Series Module Modality (0008,0060) attribute description in PS 3.3 enforces the storage of waveform and pixel data in different Series IE.
Frame of Reference Synchronization C.7.4.2 Specifies that the waveform acquisition is synchronized. Will have the same content as the image.
Equipment General Equipment C.7.5.1 Same as in the image.
Waveform Waveform Identification C.10.8 Contains references to the related image object.
Waveform C.10.9 Contains one multiplex group with the same sampling rate.

FFF.2.1.1.3.2.1 General Series Module Recommendations

A new Series is created to set the modality “ECG” for the waveform.

Most of the attributes are aligned with the contents of the related series level attributes in the image object.

The Related Series Sequence (0008,1250) is not recommended because instance level relationship can be applied to reference the image instances.

Table FFF.2. 1-8 GENERAL SERIES MODULE Recommendations

Attribute Name Tag Comment
Modality (0008,0060) “ECG”
Series Instance UID (0020,000E) Different from the one of the image object.
Series Date (0008,0021) Identical to the contents of related image object
Series Time (0008,0031) Identical to the contents of related image object.
Other attributes of General Series Module Match contents of related image object, if set there.

FFF.2.1.1.3.2.2 Synchronization Module Recommendations

The usage of this Module is recommended to encode a “synchronized time” condition, which was previously implicit when using the curve module.

Table FFF.2.1-9 SYNCHRONIZATION MODULE Recommendations

Attribute Name Tag Comment
Synchronization Frame of Reference UID (0020,0200) Same UID as in the related image object.
Synchronization Trigger (0018,106A) The value “NO TRIGGER” is used in this scenario with no external trigger signal.
Acquisition Time Synchronized (0018,1800) The value “Y” is used to allow synchronized navigation.

FFF.2.1.1.3.2.3 General Equipment Module Recommendations

The usage of this Module is recommended to assure that the General ECG SOP Instance contains identical equipment identification information as the referenced image objects.

FFF.2.1.1.3.2.4 Waveform Identification Recommendations

The usage of this module is recommended to relate the acquisition time of the waveform data to the image acquired simultaneously.

The module additionally includes an instance level reference to the related image.

Table FFF.2.1-10 WAVEFORM IDENTIFICATION MODULE Recommendations

Attribute Name Tag Comment
Acquisition Datetime (0008,002A) Exact start of the waveform acquisition taken from common (or synchronized) clock. Note: In case the ECG acquisition started before the image acquisition itself, the given datetime value is not the same as for the image.
Referenced Instance Sequence (0008,114A) Only one item used in this application case.
>Referenced SOP Class UID (0008,1150) 1.2.840.10008.5.1.4.1.1.12.1.1” i.e. Enhanced XA
>Referenced SOP Instance UID (0008,1155) Instance UID of Enhanced XA Image Object to which this parallel ECG recording is related.
>Purpose of Reference Code Sequence (0040,A170) The referenced image is related to this ECG.

FFF.2.1.1.3.2.5 Waveform Module Recommendations

The usage of this module is a basic requirement of the General ECG IOD.

Any application displaying the ECG is recommended to scale the ECG contents to its output capabilities (esp. the amplitude resolution).

If more than one ECG signal needs to be recorded, the grouping of the channels in multiplex groups depends on the ECG sampling rate. All the channels encoded in the same multiplex group have identical sampling rate.

Table FFF.2.1-11 WAVEFORM MODULE Recommendations

Attribute Name Tag Comment
Waveform Sequence (5400,0100) Only one item is used in this application case, as all the ECG signals have the same sampling rate.
> Multiplex Group Time Offset (0018,1068) If needed, specify the Group Offset from the Acquisition Datetime.
> Waveform Originality (003A,0004) The value “ORIGINAL” is used in this scenario.