Anatomic tissue atlases of the brain are widely used within the medical world and are important for identifying tissue and structural aberrations and inconsistencies within an individual. Unfortunately, there are many procedures and diseases that require examination of the brain's vascular system, which is not easily identifiable in anatomic atlases. We present a new concept of a brain vascular atlas, formed through tissue-based registration, to capture expected vascular characteristics and their variance. This vascular atlas can be used to assess the vascular variations within an individual and aid in diagnostics and pre-surgical planning. In this paper, a vascular density atlas is formed and demonstrated for use in detecting and localizing vascular anomalies.