Carotid flow disorders in patients with cerebrovascular disease: Their atraumatic assessment by carotigraphy

Abstract

Abstract Carotid arterial narrowing less than that considered to be ‘critical’ may cause turbulent blood flow. Eddying may aid the deposition of material from blood, and vortices may aid its embolization, leading to transient ischaemic attacks, the Cassandra of the stroke. Two scintillation detectors were collimated to monitor the distal portion of each internal carotid through the orbits, and a third, the root of the aorta. After the intravenous injection of 10–15 mCi of technetium-Wm, activity/time curves were obtained from 58 patients. Fourteen out of 24 patients considered to have cerebrovascular disorders had significantly different values of measured indices of carotid blood flow from a group of 24 ‘normal’ patients (P<0.02). Improvement in these indices was associated with clinical improvement in 6 patients studied bejore and after carotid endarterectomy. In 38 patients a comparison of the results of this technique (carotigraphy)and angiography was made, In unilateral carotid disease, results of carotigraphy correlate significantly with results of angiography, but bilateral symmetricnl carotid artery disease gives normal results of carotigraphy. Analysis by deconvolution of the inflow and outflow activity/time curves obtained during carotigraphy allows study of the individual artery and indicates that normal carotid arterial flow is effectively non-turbulent. The prediction of turbulent flow by carotigraphy may allow assessment of the pathogenesis and a means of prevention of many strokes.