A simple Doppler test for haemodynamically significant carotid artery disease.

A 10 MHz directional Doppler velocimeter was used to assess carotid atherosclerosis in 41 patients with cerebro-vascular disease. There were 30 men and 11 women with a mean age of 58 years. The arterial waveform pulsatility indices of the common carotid (CC), temporal (T), supratrochlear (ST), and central retinal artery (CRA) were compared with triplanar arteriograms in detecting internal carotid artery stenosis. The results were that Doppler signal ratios were able to differentiate less than 70% from greater than 70% stenosis and complete occlusion. For the diagnosis of internal carotid stenosis the ratio ST/CC had a sensitivity of 90%, a specificity of 93.5% and an accuracy of 93%. The CRA/CC ratio showed a sensitivity of 90% specificity of 72% and accuracy of 76%, and central retinal artery signals were difficult to detect. The T/CC ratio diagnosed external carotid artery stenosis of greater than 70% with a sensitivity of 90%, a specificity of 87% and an accuracy of 96%. The ST/CC and T/CC ratios were easy to perform, and employed routinely available Doppler velocimeters.