In earlier Slicer versions, slice views were initialized to be aligned with anatomical axes (as defined when the patient was scanned). In recent Slicer Preview Releases we switched to aligning slice views with voxel arrays because this seems to be what most users expect.
You can switch between the two orientations using slice view controls:
- choose an anatomical plane using the “Slice orientation” selector to align with anatomical axes
- click “Rotate to volume plane” button to snap the slice plane to volume axes
In recent Slicer Preview Releases, clicking on the eye icon in Data module automatically rotates to volume plane, unless the features is turned off (by right-clicking on the eye icon and unchecking “Reset view orientation on show”).