Noninvasive flow techniques in the diagnosis of cerebrovascular disease

The accuracy of oculoplethysmography (OPG) and carotid phonoangiography (CPA) singly and in combination, the Doppler velocity detector, and photoplethysmography (PPG) was checked by measurement of the degree of stenosis as shown on arteriograms in 308 internal carotid arteries. In a second study using arteriographic measurement in 210 internal carotid arteries, the comparative accuracy of the fluid-filled (Kartchner) and the air-filled (Zira) OPG, each with and without CPA, was assessed. In the first study the specificity in arteries with less than 40% diameter reduction varied from 88% for the PPG to 97% for the Doppler examination. The sensitivity in arteries with more than 40% diameter reduction varied from 17% for the Doppler examination to 80% for the combination of OPG plus CPA. For arteries with a reduction in diameter greater than 70%, the sensitivity varied from 67% for the CPA to 87% for the OPG plus CPA. The sensitivity of the OPG plus CPA for total occlusions was 93%. For bilateral carotid artery stenosis over 40%, the sensitivity varied from 50% for the CPA to 82% for the combined OPG plus CPA. In the second study, for arteries with less than 40% stenosis the specificity varied from 86% for the Zira computed readout to 93% for the OPG(K). In the second study, when retrospectively analyzed, the sensitivity for arteries with more than 40% stenosis varied from 74% for the Zira computed readout to 88% for the combined OPG(K) plus CPA. For arteries with greater than 70% diameter reduction the sensitivity varied from 79% for the Zira readout to 100% for OPG plus CPA. For bilateral carotid artery disease with greater than 40% diameter reduction, the sensitivity ranged from 50% for OPG(Z) to 77% for OPG(Z) plus CPA.