[Feature Request] Add support for overlapping segments

[fedorov]

What feature or change would you like to see made?

Overlapping DICOM SEG segments are currently no loaded with the error message indicating they are not supported in v3. Overlapping segments were supported in v2.

Why should we prioritize this feature?

IDC project is currently using v2, which is able to render overlapping segments. IDC contains data that contains overlapping segments, such as this one: https://viewer.imaging.datacommons.cancer.gov/viewer/1.3.6.1.4.1.32722.99.99.62087908186665265759322018723889952421. Unless this feature is implemented, this would be a regression if IDC switches to v3.

[igoroctaviano]

@sedghi @rodrigobasilio2022 will discuss a solution to this issue. A stack viewport is being implemented and might address this issue.

[james-hanks]

@sedghi link stack segmentation ticket (if we have one)

[fedorov]

Per @rodrigobasilio2022 (if I understand correctly), this is blocked by https://github.com/cornerstonejs/cornerstone3D/pull/679.

[rodrigobasilio2022]

Yes, the steps are:

• Finish this PR #679;
• Add overlapping segmentations in a new PR;
• Implement the modifications in OHIF;

[igoroctaviano]

Related to #3581

[james-hanks]

On hold because related fix will be published through industry partner project Q1 2024

[fedorov]

@james-hanks @igoroctaviano I observe that overlapping segments that are from different segmentations do work. Is this expected - that overlapping segments from different segmentations work, but from the same segmentation do not?

https://viewer.imaging.datacommons.cancer.gov/v3/viewer/?StudyInstanceUIDs=1.3.6.1.4.1.14519.5.2.1.6279.6001.191425307197546732281885591780

[fedorov]

overlapping segments from different segmentations work, but from the same segmentation do not

Yes, I confirmed the above. Interesting. The examples below can be used to demonstrate this (if you have little kids, you can ask them to play the game of "find differences" - it should be fun!):

• v2: https://viewer.imaging.datacommons.cancer.gov/viewer/1.3.6.1.4.1.32722.99.99.71961866280433925571019872464419293819

• v3: https://viewer.imaging.datacommons.cancer.gov/v3/viewer/?StudyInstanceUIDs=1.3.6.1.4.1.32722.99.99.71961866280433925571019872464419293819

I do have to point out that I find it very disturbing that you show incorrect segmentation overlay by cropping overlap areas, and do not give any warning to the user about this. Segmentations are shown as if everything is normal. This is really bad, IMHO. I hope no one is looking at any overlapping segments that are used for patient care using v3!

[sedghi]

Yes, if there are separate segmentations they will work fine.

I find it very disturbing that you show incorrect segmentation overlay by cropping overlap areas, and do not give any warning to the user about this. Segmentations are shown as if everything is normal. This is really bad, IMHO. I hope no one is looking at any overlapping segments that are used for patient care using v3!

I thought we show a warning, but tried it now and we don't, hmmmm I will look into this, but I guess your comment is about overlapping segments in one segmentation right?

[fedorov]

your comment is about overlapping segments in one segmentation right?

Correct. I think it makes sense to warn users about lack of support of overlapping segments. Ideally, it would only show up when overlapping segments are detected. I tested, and did not see any such warnings.

[sedghi]

I'm pretty sure I had that warning, not sure how it is not showing up. I will fix it in the next PR

[fedorov]

Just discovered this today (on OHIF demo viewer) that there is still no support for overlapping segments ~AND there is no any kind of warning that what you see is not what you have~ CORRECTION: the warning does show up, but it is obscured by the research software warning popup that is in front!. In this particular case, the result is very confusing.

https://viewer.ohif.org/viewer?StudyInstanceUIDs=1.3.6.1.4.1.14519.5.2.1.3671.4754.298665348758363466150039312520

This is how it should look in reality (shown in v2): https://viewer.imaging.datacommons.cancer.gov/viewer/1.3.6.1.4.1.14519.5.2.1.3671.4754.298665348758363466150039312520

[fedorov]

On hold because related fix will be published through industry partner project Q1 2024

For the record, it is way past Q1 2024, and this issue is still unresolved.