MR angiography of the head and neck.

A review of the basic physics and techniques for acquiring and evaluating magnetic resonance angiograms is provided, including time-of-flight and phase contrast techniques. Magnetic resonance (MR) angiography is becoming a routine method of evaluating carotid bifurcation atherosclerotic disease in both a screening and diagnostic capacity. The expanding clinical utility of MR angiography in the detection of intracranial aneurysms, characterization of arteriovenous malformations, and evaluation of intracranial atherosclerotic disease are also reviewed. Furthermore, MR angiography allows for the noninvasive diagnosis of arterial dissection. Magnetic resonance venography also allows the confirmation of the previously elusive and likely underdiagnosed entity of cerebral venous thrombosis.