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.22.214.171.124.2.1 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
|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.126.96.36.199.2.2 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
|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.188.8.131.52.2.3 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.184.108.40.206.2.4 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
|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)||“1.2.840.10008.5.1.4.220.127.116.11.1” 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.18.104.22.168.2.5 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
|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.|