Computerized fluoroscopy: digital subtraction for intravenous angiocardiography and arteriography.

Computerized fluoroscopy is a system comprising on-line digital time and energy subtraction algorithms designed to isolate and enhance the iodine signal from image intensified fluoroscopy. The apparatus is described and its use for time subtraction intravenous arteriography of the carotid, abdominal, extremely arteries, as well as the heart, is illustrated. Vascular diseases such as stenoses, obstruction, emboli, ulcerative plaques, and aneurysms are readily demonstrated. The technique has a potential for evaluating cardiac motion and the patency of coronary artery bypass grafts. The method appears to be a safe and less expensive alternative to catheter arteriography and angiocardiography in certain instances.