Fusion in the OHIF Viewer, and its development status

Hey everyone, glad to see their is a new discussion forum :slight_smile:

I have been working on extending OHIF’s Viewer to allow it to perform fusion in both 2D and 3D via the VTK extension. So far I’ve added features like repositioning, rotation, CT transfer function selection, and PET color map selection.

I visited the Slack channel asking about making a PR for this feature as its almost done, and they explained that the OHIF team was already working on this feature.

I was hoping to view the most recent branch for the development of this feature, so that I may contribute any work already done that you folks may have not had time to add.

Below are some screenshots of what I’ve done so far:


Out of curiosity, did you figure out what to do? My company also has contributions that we’re trying to decide out how to handle and I’d love to hear more about your experience. This whole thing feels a little sticky:

  1. It looks like all development has switched to V3 of the viewer, which has a VERY different internal architecture not compatible with the current V2. (I’m reaching this conclusion after looking at https://ohif.org and the docs, which mark V2 as no longer maintained and relying on the architecture notes.)
  2. V3 is still in a relatively immature state of development, and lacks support for A LOT of features that V2 current supports: DICOM PDF, HTML, segmentation, RT STRUCT, upload to PACS, and VTK/MIP extension.
  3. The plans for VTK/MIP are to replace replace it with a new visualization library that looks awesome but is still not available for review.

For us, we’re feeling a little stuck. We’ve built on top of the V2 architecture and use the existing VTK features. For that reason, until V3 catches up to V2 we haven’t wanted to invest time/effort into re-working for the new OHIF codebase. (We’re also not clear how to go about contributing to related projects like DCMJS, which it seems like would be necessary to enable additional DICOM-SR support.)

If you’ve got any thoughts about what you’re project is doing, I would love to hear them.

Hey Robert,

thanks for your comment. I understand where you are coming from, I suppose this is a natural side effect of working with open-source software. I am a developer for a small startup, not a project manager by any means. My manager found OHIF V2 (or at least, parts of it) to be the best solution for our needs, and I have simply been adding the features it lacks on an as-needed basis. Therefore, I can’t offer much insight into the high-level problem you are facing unfortunately.

What I can say is in our case we are going to pick apart OHIF Viewer V2 and integrate it into our pre-existing application / UI. From what I can tell, we will be keeping the cornerstone viewport, the react-vtkjs-viewport, and their corresponding segmentation tools.

I think this makes our decision to stick with it for developing features before we take it apart for our own use case a lot safer then if we were planning on relying on the fully functional application for the foreseeable future.

We’re also not clear how to go about contributing to related projects like DCMJS

I have had to fork and make changes to DCMJS already for certain features, and am now doing the same for react-vtkjs-viewport. Ideally I will create pull requests when I have time to give back to the DCMJS community, and receive community support for those features from those who are more knowledgeable about these subjects than myself.

I’d like to also contribute my fusion feature to OHIF V2, but with the state of its development being more or less stopped, that is becoming less likely. I have gotten our fusion feature to a point where we are satisfied with it (for now), and am now working on expanding the segmentation capabilities offered in OHIF’s react-vtkjs-viewport.

If it sounds like you are trying to develop similar features as my company, perhaps we can have a conversation about collaborating on bringing these features to life as a team in order to save time and money for both of us. Just a thought. Either way best of luck!

I haven’t heard of the news to replace VTK with a new visualization library, could you provide me with a source for where you heard this news? That would be much appreciated :slight_smile: