I am doing some segmentation on MRI data (nii.gz) I am trying to label a very small stucture. After zooming in and trying to paint with the smalles size of the brush it produces a very strange square labels.
If you switch to the latest stable release of Slicer (currently 4.10.2) then you’ll get a warning icon displayed when the slice view is not aligned with any of the volume axes. You can align slice views by clicking that icon: