In 2.2.1 (115), I have had issues importing DICOM images. They seem to import as plain white boxes. I can resolve the issue by uninstalling and reinstalling, but that is a very inconvenience workaround.
EDIT: Now even reinstalling the program does not seem to correct the issue. I would add that there does not seem to be an issue with the DICOM image, itself, as it will open in other DICOM-reading programs.