My clinical work is in TB control and we read a lot of chest X-rays and CT scans. I'm very used to DICOM and I have my personal preferences for DICOM viewers, but outside of an actual radiology suite most docs will just use whatever viewer came on the disc, if there's one at all. And that's largely true for the ones I've worked with in this field, too.

That said, I was in IT before I got my MD.