OHIF Import Measurements

The most relevant question raised in OHIF issues: https://github.com/OHIF/Viewers/issues/1800 Version 3.10.2

Figure The overall limitation of the single route per mode.

Forming Working Prototype. We first extract trackedMeasurements and use it as a reference format of data we going to deal with when importing measurments:

const measurements = measurementService.getMeasurements();

Then we use data to form the following request to measurement service (addRawMeasurement).

Important: We need to place this code after cornerstone is avaialble to display related content.

Next crucial problem is to reshape measurements and distribute them across addRawMesurements input parameters.

• First, we need source that is aligned with the one in measurements by guid.
• The same is for further mappings, i.e. sourceMappings.

1. For that, measurementService provides related API:

    const CORNERSTONE_3D_TOOLS_SOURCE_NAME = 'Cornerstone3DTools';
    const CORNERSTONE_3D_TOOLS_SOURCE_VERSION = '0.1';
   
    const source = measurementService.getSource(
        CORNERSTONE_3D_TOOLS_SOURCE_NAME,
        CORNERSTONE_3D_TOOLS_SOURCE_VERSION
    );
   
    const mappings = measurementService.getSourceMappings(
        CORNERSTONE_3D_TOOLS_SOURCE_NAME,
        CORNERSTONE_3D_TOOLS_SOURCE_VERSION
    );
   

Because data don’t have cachedStats. Do we have to manually register. We can assign default values {}. And it works!

• However it should not be empty, as in UI you won’t see info about H/Width of the measurement.

    const annotation = {
      data: {
          // Manually add.
          cachedStats: {}
          ...
      }
    }
  

• Therefore we need to put data with key equals to referencedImageId at cachedStats as follows:

    // That duplicates the metadata content but would need for cornerstone to display.
    // See later: requires added imageId.
    'wadors:http://127.0.0.1/OrthancNginx/dicom-web/studies/1.2.86.76547135.7.1323518.20210710080000/series/1.2.826.0.1.3680043.8.274.1.1.8323329.418900.1748947477.387488/instances/1.2.826.0.1.3680043.8.274.1.1.8323329.418900.1748947477.387555/frames/1': {
  length: 301.21672688578593,
  width: 200.81115125719057,
  unit: 'mm',
  widthUnit: 'mm',
    },
  

Register annotation UID as well * This could be done as: js const annotation = { // annotationUID: toolData.annotation.annotationUID, annotationUID: '11570db5-d2a8-4868-a6e7-6017bc230710', }

Next, is Problem on cornerstone side with rendering Bidirectional measurement.

• By exploring code, this step involves instantiation of the measurement (copy creation). I belive this process not entirely smooth and causes futher misalignments at rendering stage resulted in exceptions.

  • Then you get an exception:

    Error: getTargetIdImage: targetId must start with "imageId:" or "volumeId:"
    

    because key in cached data should start with “imageId:” …

  • For some reason, cornerstone attempt to draw it with circular tool. Eitherway the problem for now is that no points (for some reason) is available to render this content.

    When this call happens.

    const svgDrawingHelper = getSvgDrawingHelper(element);
    

    at drawHandles.js

    drawHandle(svgDrawingHelper, annotationUID, handleGroupUID, handle, options, i);
    

    handle is None.

    After further investigations I found that activeHandleCanvasCoords is undefined, which is not equals to None (Tools/dist/esm/tools/annotation/BidirectionalTool.js)

    Expects activeHandleIndex that at least should be null (not undefined)

    The solution: cornerstone expects activeHandleIndex: null, so we have to add so in handles.

    const annotations = {
      handles: {
          // Important for handling with cornerstone for Bidirectional type.
          activeHandleIndex: null
      }
    }
    

And that’s it 🥳

The function:

function importMeasurement(measurementService, measurement) {
  const CORNERSTONE_3D_TOOLS_SOURCE_NAME = 'Cornerstone3DTools';
  const CORNERSTONE_3D_TOOLS_SOURCE_VERSION = '0.1';

  const source = measurementService.getSource(
    CORNERSTONE_3D_TOOLS_SOURCE_NAME,
    CORNERSTONE_3D_TOOLS_SOURCE_VERSION
  );

  const mappings = measurementService.getSourceMappings(
    CORNERSTONE_3D_TOOLS_SOURCE_NAME,
    CORNERSTONE_3D_TOOLS_SOURCE_VERSION
  );

  const annotationType = measurement.metadata.toolName;

  
  // TODO. Add label restoration.
  const annotation = {
    annotationUID: measurement.uid,
    metadata: measurement.metadata,
    data: {
      cachedStats: measurement.data,
      handles: {
        activeHandleIndex: null,
        points: measurement.points,
      },
    },
  };

  const matchingMapping = mappings.find(m => m.annotationType === annotationType);

  measurementService.addRawMeasurement(
    source,
    annotationType,
    { annotation },
    matchingMapping.toMeasurementSchema
  );
}