collaboration in radiology requires at least a viewer, up to this point they partnered with companies like DICOM Grid to provide that functionality. The other thing you'd need is to reach into the infrastructure, behind the firewall and get the images off the legacy PACS (Picture Archive and Communication Systems). This is done via the DICOM protocol. Box didn't have this part, instead, they asked doctors to UPLOAD images to Box to view them. In the above press release, Levie specifically talks up legacy integration. This is what he's talking about. Being able to reach in and get the images, most of the time automatically, view them in the web, add to that already existing collab features Box has been building (documents, notes, etc), and you've got what could become the next-gen radiology platform - at least a more effective medical image exchange.

Disclosure, I was chief architect at DICOM Grid and built similar functionality there.