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Viewer Indexing Errors

In order for DICOM files to load and be rendered in the V2 viewer, they first need to be indexed in Flywheel’s DICOM Web service. In some cases, it is possible that DICOM files have not been indexed before you try and open them in the V2 viewer. The viewer will then automatically try and index them into Flywheel’s DICOM Web Service so they can be loaded.

It is possible, however, that DICOM files still cannot be indexed and therefore loaded into the Viewer. There can be a lot of different reasons as to why that is the case, but there are some that are more common that others, and for which the Viewer will provide more information.

Unsupported modality

The V2 Viewer supports a wide variety of imaging modalities, but the following modalities are currently not supported:

  • Presentation State: PR
  • Key Object Selection: KO
  • Radiotherapy Dose: RTDOSE
  • Radiotherapy Plan: RTPLAN

If the file you are trying to open in the Viewer is of one of these modalities, the Viewer will return a message to indicate that the modality is not supported.

unsupported modality indexing error

UID conflict

For a DICOM series to be properly indexed in Flywheel’s DICOM Web service, it must be the only DICOM file with the unique set of StudyInstanceUID (0020,000D) / SeriesInstanceUID (0020,000E) in the Flywheel project. If there are more than one file with the same StudyInstanceUID or SeriesInstanceUID in the same project, the Viewer cannot retrieve those files, and returns an error message to indicate which other file has the same UIDs. A link to the acquisition containing the conflicting file is also provided.

In order to resolve the issue, the StudyInstanceUID and SeriesInstanceUID of the conflicting file can be replaced by new ones using Flywheel’s dicom-fixer gear with the new-uids-needed config option turned on. Alternatively, files with duplicate UIDs can also be removed from the project.

uid conflict indexing error

DICOM header parsing issue

Indexing DICOM data into the Flywheel’s DICOM Web service requires specific DICOM tags to be present in the DICOM files. If for some reason any of these DICOM tags is missing, or has an empty or unexpected value, the files cannot be indexed and cannot be viewed in the Viewer.

The Viewer returns an error message to indicate that some DICOM headers could not be parsed and the data cannot be indexed.

In order to view the file the problematic DICOM tags will need to be fixed. This can be done with tools such as the dicom-fixer gear in Flywheel, or the 'dcmodify' tool from the DICOM toolkit (DCMTK) library.

dicom header parsing error

Other indexing issues

For other indexing issues, the viewer returns a generic error message indicating that the DICOM data cannot be indexed and provides an error ID. If that is the case, please contact either you site administrator or Flywheel’s support and reference that error ID.

general indexing error