Intravenous angiography of the extracranial cerebral arteries.

Intravenous angiography with systematic subtraction is a simple, physiological method of simultaneously studying the common carotids, carotid bifurcations, internal carotids (up to the carotid siphons), and vertebral arteries. It can be employed in fasting patients without anesthesia or premedication and without the risks of an arterial approach. Used in 500 patients (of whom 30% were outpatients and some were older than 80), it was tolerated well, easily repeated, and gave 80.6% good or excellent results and only 19.4% poor or uninterpretable results. This is a practical method of screening atheromatous lesions and monitoring their development, particularly after surgery.