Common carotid artery occlusion. Role of non-invasive and angiographic analysis.

Doppler and B-scan imaging, periorbital directional Doppler, and occuloplethysmography correctly identified common carotid occlusion in three of four consecutive patients with atherosclerosis. High-grade common carotid stenosis in the fourth patient could not be distinguished from occlusion on the non-invasive tests. Occlusion of the internal carotid artery in one patient and patency of that artery in the other three were evident non-invasively. Modified angiography agreed with non-invasive tests in each of three patients studied. Intra-arterial digital subtraction angiography in the fourth patient suggested but could not confirm patency of the internal carotid artery indicated by non-invasive criteria.