This document discusses evaluating and characterizing space occupying lesions in the brain. It lists potential causes of such lesions including tumors, infections, hemorrhages, infarcts, demyelinating diseases, and vascular lesions. Differential diagnoses are provided for specific cases, such as a 79 year old woman with bleeding from her left ear and a pontine lesion. The document emphasizes detecting, localizing, and determining the nature of any space occupying lesions found.