The systems I designed and installed used HP ProLiant DL380s with 2 nVidia GTX460s, 196 GB RAM, 2 hex-core Xeon procs, and redundant 4Gb qLogic fiber HBAs. Apple didn’t even make a product that could match that at the time let alone support iOS on that platform if we could make it work. It comes down to ease of deployment and use. MOST radiology professionals know PACS, and it’s not supported on Apple hardware at this time.