I had this Elsevier application on my tablet where you can look at human anatomy, with a quite fancy 3d viewer. But then it turned out you had to pay like $80 per year to keep using it. I'm not sure how good their viewer is but glad people are working on open alternatives.
Also, at least at the hospital I attended, if you get a CT scan and then get a copy of the results, it comes with a free viewer on the DVD. You aren't limited to the data on the DVD. I have loaded other visualizations in the software just fine.