Noninvasive measurement of velocity profiles and blood flow in the common carotid artery by pulsed Doppler ultrasound.

A computer-controlled 14-channel pulsed Doppler ultrasound instrument was used as a noninvasive means to evaluate instantaneous velocity profiles and flow in the comlon carotid arteries of 22 healthy persons and in 22 patients. Of the later, 13 had severe obstructions of the extracranial portion of the carotid artery, four had obstruction of the intracranial portion, and five had severe aortic valve insufficiency (AI), with more than 60% regurgitation in all cases. Measurements could be performed within an accuracy of about +/- 20% under clinical conditions and revealed perfusion values of 5 to 8 ml per second (300 to 480 ml per minute) in healthy persons. Of the patients, values less than 3 ml per second (180 ml per minute) were detected in nine, between 3 and 5 mm per second (180 to 300 ml per minute) in four, and normal values in another four, while significant backflow was observed only in patients with severe AI. Consecutive blood flow profiles were recorded every 4 msec; these demonstratedthat, for ...