Imaging has become a central part of the evaluation of lesions of the central nervous system. Despite patterns of the appearances of several types of central nervous system malignancies and improving resolution of imaging techniques, there are other processes that can display similar characteristics. Time and again, vascular, inflammatory, and vascular lesions will mimic a neoplastic process, requiring tissue diagnosis. With the introduction of advanced magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging in the evaluation of the brain tumor, there has been improvement in determining whether a lesion is neoplastic, and further advances may lead to noninvasive pathological and molecular diagnoses.