Материал: part17

Figure FFF.1.5-2. Example of Manufacturer-Dependent Subtractive Pipeline with Enhanced XA​

FFF.2 Application Cases​

Thischapterdescribesdifferentscenariosandapplicationcasesorganizedbydomainsofapplication.Eachapplicationcaseisbasically​ structured in four sections:​

1)User Scenario: Describes the user needs in a specific clinical context, and/or a particular system configuration and equipment​ type.​

2)Encoding Outline: Describes the specificities of the XA SOP Class and the Enhanced XA SOP Class related to this scenario, and​ highlights the key aspects of the Enhanced XA SOP Class to address it.​

3)Encoding Details: Provides detailed recommendations of the key Attributes of the object(s) to address this particular scenario.​

4)Example: Presents a typical example of the scenario, with realistic sample values, and gives details of the encoding of the key​ Attributes of the object(s) to address this particular scenario. In the values of the Attributes, the text in bold face indicates specific​ Attribute values; the text in italic face gives an indication of the expected value content.​

FFF.2.1 Acquisition​

FFF.2.1.1 ECG Recording at Acquisition Modality​

This application case is related to the results of an X-Ray acquisition and parallel ECG data recording on the same equipment.​

FFF.2.1.1.1 User Scenario​

The image acquisition system records ECG signals simultaneously with the acquisition of the Enhanced XA Multi-frame Image. All​ the ECG signals are acquired at the same sampling rate.​

The acquisition of both image and ECG data are not triggered by an external signal.​

The information can be exchanged via Offline Media or Network.​

Synchronization between the ECG Curve and the image frames allows synchronized navigation.​

Figure FFF.2.1-1. Scenario of ECG Recording at Acquisition Modality​

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FFF.2.1.1.2 Encoding Outline​

The General ECG IOD is used to store the waveform data recorded in parallel to the image acquisition encoded as Enhanced XA​ IOD.​

The Synchronization Module is used to specify a common time-base.​

The option of encoding trigger information is not recommended by this case.​

The solution assumes implementation on a single imaging modality and therefore the mutual UID references between the General​ ECG and Enhanced XA objects is recommended. This will allow faster access to the related object.​

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.2.1-1. Enhanced X-Ray Angiographic Image IOD Modules​

Table FFF.2.1-2. Enhanced XA Image Functional Group Macros​

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​

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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​

FFF.2.1.1.3.1.4 Enhanced XA/XRF Image Module Recommendations​

TheusageofthismoduleisrecommendedtoreferencefromtheimageobjecttotherelatedGeneralECGSOPInstancethatcontains​ the ECG data recorded simultaneously.​

Table FFF.2.1-5. Enhanced XA/XRF Image Module Recommendations​

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​

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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​ PS3.3.​

Table FFF.2.1-7. General ECG IOD Modules​

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​

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​

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.​

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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​

FFF.2.1.1.3.2.5 Waveform Module Recommendations​

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

AnyapplicationdisplayingtheECGisrecommendedtoscaletheECGcontentstoitsoutputcapabilities(esp.theamplituderesolution).​

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​

FFF.2.1.1.4 Examples​

In the two following examples, the Image Modality acquires a Multi-frame Image of the coronary arteries lasting 4 seconds, at 30​ frames per second.​

Simultaneously, the same modality acquires two channels of ECG from a 2-Lead ECG (the first channel on Lead I and the second​ on Lead II) starting one second before the image acquisition starts, and lasting 5 seconds, with a sampling frequency of 300 Hz on​ 16 bits signed encoding, making up a number of 1500 samples per channel. The first ECG sample is 10 ms after the nominal start​ time of the ECG acquisition. Both ECG channels are sampled simultaneously. The time skew of both channels is 0 ms.​

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