Материал: part17

FFF.2.1.2.1.3.2.1 Waveform Identification Recommendations​

The usage of this module is recommended to relate the acquisition time of the waveform data to the related image(s).​

Table FFF.2.1-18. Waveform Identification Module Recommendations​

FFF.2.1.2.1.4 Example​

In this example, there are two modalities that are synchronized with an external clock via NTP. The Image Modality acquires three​ Multi-frame Images within the same Study and same Series. Simultaneously, the Waveform Modality acquires the ECG non-stop​ during the same period, leading to one single Waveform SOP Instance on a different Study.​

In this example, there is no UID referencing capability between the two modalities.​

Figure FFF.2.1-7. Example of Multi-modality Waveform Synchronization​

The Attributes that define the relevant content in the two different SOP Instances (Enhanced XA and General ECG) are described in​ Figure FFF.2.1-8.​

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Figure FFF.2.1-8. Attributes of Multi-modality Waveform NTP Synchronization​

FFF.2.1.2.2 One Modality Sends Trigger to The Other Modality​

FFF.2.1.2.2.1 User Scenario​

Image runs are taken by the image acquisition modality. Waveforms are recorded by waveform recording modality. Both modalities​ are time synchronized via NTP. The acquisition in one modality is triggered by the other modality. The resulting objects will include​ the time synchronization and trigger synchronization concepts.​

There are two cases depending on the triggering modality:​

1- At X-Ray start, the image modality sends a trigger signal to the waveform modality.​

2- The waveform modality sends trigger signals to the image modality to start the acquisition of each frame.​

Figure FFF.2.1-9. Scenario of Multi-modality Waveform Synchronization​

FFF.2.1.2.2.2 Encoding Outline​

Dedicated Waveform IODs exist to store captured waveforms. In this case, General ECG IOD is used to store the waveform data.​

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With the Synchronization Module information, the method to implement the triggers can be documented.​ The Enhanced XA IOD provides per-frame encoding of the timing information related to each frame.​

FFF.2.1.2.2.3 Encoding Details​

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

FFF.2.1.2.2.3.1 Enhanced XA Image​

Table FFF.2.1-19. Enhanced X-Ray Angiographic Image IOD Modules​

Table FFF.2.1-20. Enhanced XA Image Functional Group Macros​

FFF.2.1.2.2.3.1.2 Enhanced XA/XRF Image Module Recommendations​

This module includes the acquisition date and time of the image.​

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FFF.2.1.2.2.3.2 Waveform Object​

The recording system will take care of filling in the waveform-specific contents, based on the IOD relevant for the type of system (e.g.,​ EP, Hemodynamic, etc.). This section will address only the specifics for Attributes related to synchronization.​

Table FFF.2.1-24. Waveform IOD Modules​

FFF.2.1.2.2.3.2.2 Synchronization Module Recommendations​

The usage of this Module is recommended to document the triggering role of the waveform modality.​

Table FFF.2.1-25. Synchronization Module Recommendations​

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FFF.2.1.2.2.3.2.3 Waveform Identification Module Recommendations​

This module includes the acquisition date and time of the waveform, which may be different than the acquisition date and time of the​ image in this scenario.​

Table FFF.2.1-26. Waveform Identification Module Recommendations​

modality.​

It may be different from the Acquisition DateTime of the Enhanced XA​

SOP instance.​

FFF.2.1.2.2.3.2.4 Waveform Module Recommendations​

The usage of this module is recommended to encode the time relationship between the trigger signal and the ECG samples.​

Table FFF.2.1-27. Waveform Module Recommendations​

FFF.2.1.2.2.4 Examples​

FFF.2.1.2.2.4.1 Image modality sends trigger to the waveform modality​

In this example, there are two modalities that are synchronized with an external clock via NTP. The Image Modality acquires three​ Multi-frame Images within the same Study and same Series. Simultaneously, the Waveform Modality acquires the ECG non-stop​ during the same period, leading to one single Waveform SOP Instance on a different Study. The ECG sampling frequency is 300 Hz​ on 16 bits signed encoding, making up a number of 1500 samples per channel. The first ECG sample is acquired at nominal start​ time of the ECG acquisition.​

The image modality sends a trigger to the waveform modality at the start time of each of the three images. This signal is stored in​ one channel of the waveform modality, together with the ECG signal.​

In this example, there is no UID referencing capability between the two modalities.​

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