Free Neuroradiology Cases adds another option to radiology learning apps
Radiology, however, is starting to have a large number of high quality medical apps to choose from.
If you split the field into categories, there are DIACOM apps, journal apps, and then a growing body of radiology learning apps. Among the radiology learning apps there are enough now that you can almost pick subcategories (see PediatricXR, surgical radiology, radiology 2.0 One Night in the ED, and RealWorld orthopaedics).
Neuroradiology offers a well made introduction to its field. You can pick from one of three categories including Brain, Head and Neck, and Spine. In each category there are over ten cases ranging from pineoblastoma to schwannoma.