Problems with volume rendering (location/deformation/orientation)

Hi! I’m new to Slicer 3d, so hopefully this is not a software problem, but only user error…

When I’m doing 3d segmentation, everything seems to work as expected, but when I try volume redering, the 3d volume seems to end up in the wrong position, deformed, and with incorrect orientation.

If I enable Crop in the volume rendering settings (and the ROI includes all the image areas in the the three projections), the 3d view contains nothing. I have to disable cropping for something to appear in the 3d view. If I show the ROI-cube in the 3d view, it is not located at the same place as the volume.

When I do a 3d segmentation first, and then do the volume rendering, the volume is not located at the same place in the 3d view as the 3d segmentation. I have attached a screenshot of this. The green skull is the segmentation, and the volume is located above, squeezed together, and not oriented in the same way as the segmentation.

I’m using Slider 3d nightly, and with CPU volume rendering. It is the same when using GPU volume rendering.

I also have some DICOM-data from a different CT, and in that case there is still a problem with the placement of the volume, but in that case it is not squeezed together (in that case the voxel size is uniform).

I’m on Windows 10 with a NVIDIA Quadro M2200 graphics card.

slicer_problem

Unfortunately, volume rendering does not support dynamic application of non-linear transforms. If you harden the transform (in Transforms module, click on image button in Apply transform section) then it will work correctly.

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