Oculoplethysmography and carotid phonoangiography for the noninvasive detection of extracranial carotid occlusive disease.

Clinical applications of imaging techniques and noninvasive physiological vascular evaluations provide useful assistance in the detection and management of stroke-prone patients by minimizing unnecessary carotid arteriography and surgery. Two such evaluation techniques are oculoplethysmography (OPG) and carotid phonoangiography (CPA). Developed, used, and proved highly reliable at the Tucson (Arizona) Medical Center, the techniques have been documented in 12,000 tests on approximately 8500 patients. OPG simultaneously records the bilateral ocular pulses concomitantly with external carotid pulses. Delays in timing of these pulses reflect reduction of flow in the internal and/or external carotid arteries, respectively. CPA consists of electronic stethoscopic auscultation, direct visualization, and photographic recording of carotid bruits or blood flow sounds.