Some people ask me what we use to annotate medical imaging data. Here's my answer ↓
Usually, we don't annotate medical data by ourselves. We work with certified 3rd party companies to do this.
But what if I want to do some minor modifications on some annotation?
In this case, we use 2 freely available software programs: 3D Slicer and ITK Snap.
They both make it easy to visualize all sorts of medical data formats including: DICOM, NIFTI and NRRD.
Btw, we don't just use them to make modifications to medical annotations.
We also use them to do data verification and validation, which is a crucial step in every project we take at PYCAD.
When do we use which?
Generally speaking, ITK Snap is my go to for a quick data visualization and checking. Mostly because it opens up quicker than 3D Slicer 😅
But if I want to do a thorough check of the data and have more control, then I go with 3D Slicer.
But when I want to do a thorough data verification and validation, I actually open the file I'm inspecting in both softwares.
This helps in some edge cases where the person who did the annotation used 3D Slicer and saved the file in some generic way.
When an annotator does this, it could hide some information that are crucial for any ML project.
For example, we noticed that sometimes when we open an annotation file in 3D Slicer, we see: segment_1, segment_2, ...
These would be the names of the annotated classes.
If you just look at this, you'll think that segment_1 has label 1, segment_2 has label 2 so on..
But in reality, it could be that segment_1 has label 2, segment_2 has label 5, ...
This could happen when the annotator creates a segment (annotation), then deletes it and creates a new one. 3D Slicer keeps the information of the deleted segment but hides it away.
When we open the same patient file in ITK Snap, we immediately notice the discrepancy in the labels.
This is just one of the possible scenarios.
Keep this in mind next time you're working on a medical imaging project.
💊 Btw, if you need help developing AI solutions for medical imaging, we at PYCAD can help you with that. Feel free to DM for more information!
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