MR angiography in neurologic disease.

Magnetic resonance (MR) angiography has rapidly evolved over the past few years to become a technique that is commonly used in clinical practice as part of the diagnostic work-up of patients with suspected neurologic disease. In this review, the author provides a brief overview of the relevant biophysical principles and some fundamentals of flow imaging by using MR as a baseline for understanding and implementing MR angiography in these patients. A historical perspective is given as a way of emphasizing the need for a healthy degree of skepticism rather than enthusiasm alone when reading MR angiographic literature. The rationale and clinical needs for MR angiography are summarized. The available data from blinded reader studies are summarized for two major clinical entities in which MR angiography is often used in neurologic practice: atherosclerotic disease of the extracranial carotid bifurcation and intracranial aneurysms. Recent refinements and technical innovations are also noted.