Computed tomography (CT) and magnetic resonance imaging (MRI) are crucial tools for refinement of preoperative differential diagnosis, precise anatomical localization for operative planning, detection of response to therapy and of tumor progression, and recognition of treatment-related side-effects. Despite the value of MRI and CT in the management of patients with nervous system tumors, however, there are still significant limitations surrounding the lack of specificity inherent in an in vivo gross anatomical analysis of a mass lesion. The technical versatility of MRI is leading to new techniques that permit analysis of the chemical composition of tumor tissue, capillary density, and the diffusion of water. These advances hold great promise but are not yet well validated. In addition to an overview of the anatomical imaging features of brain tumors, this chapter will address these advances.