Question about the 3D segmentation of organs about medical-sam2

[heyoeyo]

From what I've seen from the original SAM2 (and I assume Medical-SAM2), the model is pretty robust to changes to the frame ordering (you can give frames out-of-order and it still works), though giving continuous looking sequences (whether regular or reversed order) should work best.

So it should be fine to pick a frame where it's easy to get a good segmentation, then propagate 'forward in time' until the segmentation is lost, then go back to the prompted frame (and reset the memory bank) and run 'backwards in time' to get the segmentations for frames prior to the prompted frame.

[jiayuanz3]

yes, I agree the comments provided by @heyoeyo and thanks for the well explanation. additionally, the two quotes we are referring to the One-prompt Segmentation capability in 2d cases, regardless of temporal relationships between the images.

[AlexanderZeilmann]

Thank you to both of you! I understand now.

So the complete workflow would be to

1. Go to the first labelled slice and segment forward and backward in the volume to create a (partial) segmentation of the volume.
2. Go to the second labelled slice and create another partial segmentation. Similarly for all other labeled slices.
3. Combine the partial segmentations to a "complete" segmentation of the volume.
4. Show to the user for further annotations.
5. Repeat.