Setup help and recommendations

General
1

Hello, good day.
I was wondering if anyone could help or guide me.
I’m currently running orthanc and ohif in Docker, and everything works perfectly. But I’m having problems and delays, for example, when I have mammograms or studies from an indirect digital scanner (CR). For example, a mammogram, with four images each, weighs approximately 15 to 20 MB, and it usually takes a while to display it.

I’d like to know how I can improve the performance of the system itself. Can I do something in the orthanc configuration? I’m a bit lost here and haven’t been able to find anything. Is it okay to transfer the 60-80 MB to, for example, display it on a mobile device?

I’m building my application, and I’m not sure if I’m doing things right.

Docker image: jodogne/orthanc-python,
Ohif: @4.12.51

I’m leaving my orthanc configuration.

Regards
Cristian.
orthanc (1).json (3.4 KB)

2

Hi,

To reduce the bandwidth usage, you can modify the IngestTranscoding configuration and set it to 1.2.840.10008.1.2.4.90 (JP2K) or 1.2.840.10008.1.2.4.70 (JPG Lossless).

Note that you’ll need to re-ingest your data after this change (or run the Housekeeper plugin)

Hope this helps,

Alain

3

Hi Alainmazy, thanks for your response.
Now my question is, by enabling this option,
Questions:

  1. If I send the same study twice, it will be duplicated, right? Can something be done to prevent this from happening?
  2. When compressing in lossless JPG, the SOPInstanceUID changes, I imagine.
  3. If I use this option 1.2.840.10008.1.2.4.70, do you know approximately how much I compress in percentage?
  4. Can I store uncompressed images with orthanc, and when ohif requests images, will they be transferred in lossless JPG?

Thanks for your help.
Regards
Cristian

4

Hi,

No, they wont’ be duplicated if they have the same DICOM IDs.

No, this only happens when compressing to Lossy transfer syntaxes.

Around 2.5x compared to raw image.

OHIF will usually not request transcoding and will therefore get them in raw if Orthanc saves them in raw.

HTH,

Alain

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5

Hello,

In addition to Alain’s answer, note that the Stone Web viewer implements progressive loading, contrarily to OHIF and VolView. More precisely, the Stone Web viewer first downloads a low-resolution JPEG preview of the DICOM instances, then downloads the full-resolution DICOM file. This allows to improve the user experience over a slow network.

Also, note that you might be in the context where the on-the-fly multi-resolution pyramids implemented in the whole-slide imaging plugin for Orthanc might be beneficial. However, we do not currently provide an advanced user interface for this feature (the user interface only displays one instance, with no annotation tool).

Kind Regards,
Sébastien-

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