You point out another business opportunity: a developer who understands exactly what regulatory hurdles you need to jump in order to release medical software. I'm not sure exactly what's required in this case, but I'm doubtful there are many cloud providers who are HIPAA compliant.

I'm not sure it would need to be regulated, any more than a medical textbook needs to be regulated. The radiologist would be making any decisions. As for privacy, an x-ray is sent. No personal information whatsoever.