Cervical carotid imaging with a continuous-wave Doppler flowmeter.

Cervical Carotid Imaging With a ContinuousWave Doppler Flowmeter • A noninvasive technique for carotid arteriography using an ultrasonic directional Doppler flowmeter to image the carotid bifurcations is described. The technique uses a position sensing arm to hold the sharply focusing probe and translates the position of arterial flow onto an image storage screen. By multiple manual sweeps across the cervical carotids, a two-dimensional projection of the locus of arterial flow is developed. The probe beam is then applied through the eyelids to assess the posterior orbital ophthalmic flow. The adequacy of the internal carotid circulation and the presence of stenosis and calcified plaques are determined. Experience with the first 60 patients surveyed using the Doppler technique demonstrated a high degree of accuracy and reproducibility. The ultrasonic angiography provided local flow and velocity information that x-ray angiography did not. X-ray angiography is frequently indicated by the ultrasonic findings when risks of x-ray angiography might not otherwise be taken. The technique was found especially sensitive in detecting calcified atherosclerotic plaques and may be used in screening for the stroke-prone patient and following arterial lesions over extended periods of time. Additional