Imaging of cerebral perfusion, particularly by the dynamic tracking of a bolus of gadolinium-based contrast agent, has emerged from the experimental laboratory and become a routine aspect of neuroradiologic practice. This article discusses the practical implementation of "perfusion" protocols into neuroradiologic examinations, as well as discussing the role of postprocessing and quantitative interpretation in terms of vascular physiology and function. Several key clinical indications are introduced, such as acute cerebral ischemia, chronic vascular disease, and tumors.