I know of one mathematical system that was used before the widespread use of CT scans of brain in diagnosing stroke type. That of Scoring methods, which gave at those days a clinical decision that is by way much better than the clinical decision made by highly ranked experienced professional Consultant Neurologists. An example of a score that I myselfmyself researched was the Allen Score in differentiating stroke type, i.e. hemorrhagic from ischemic strokes.
I personally think that along similar lines we can get machines to overcome the experienced human diagnosis in many fields in medicine, albeit not always of course.