Aligning a surface model and volume rendering of the same skull

Hi community.

I have the DICOM files of a skull and the Surface model (in PLY format) separately.

When I load both into Slicer, and do the volume rendering of the DICOM files, I can see that they are NOT aligned.

How can I align/superimpose both (volume rendering and surface model)?


This seems like RAS vs LPS coordinate issue. What happens when you choose the coordinate system for your 3d Model explicitly during the load.

Thats perfect. By changing to RAS the surface model load it was perfectly aligned. Thanks

Where did you do this segmentation? If this was done in slicer, this shouldn’t have happened.

Yes, I did my segmentation in Slicer. My flow was:

  1. Load the skull and segment it entirely.
  2. Export model to PLY format.
  3. Load the DICOM files and do volume rendering.
  4. Load the exported PLY file.


Can you share a one dataset of dicom and segmentaiton. This should not have happened, if you exported from Slicer.

@pieper @lassoan

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