Carotid ultrasonography in carotid artery disease.

Real-time high resolution carotid ultrasonography was performed in 1,300 patients of whom 294 also had carotid arteriography, allowing evaluation of 586 extracranial carotid vessels. Of the 586 extracranial vessels studied, 411 were normal by arteriography; of these, 381 (93%) were also normal by ultrasonography or showed only superficial plaques. Of the 175 vessels that were abnormal by arteriography, 153 (87%) were abnormal by ultrasonography. There were 30 (7%) false-positive and 22 (13%) false-negative ultrasonic studies. The sensitivity was 87% and the specificity was 93%. Oculoplethysmography (OPG) done on these patients had a sensitivity of 43% and a specificity of 93%; nuclear angiography had a sensitivity of 40% and a specificity of 77%. The ultrasonography, OPG, and nuclear angiography results are based on the assumption that the sensitivity and specificity of carotid arteriography are 100%, but studies have shown that it is not that accurate. Carotid ultrasonography appears to be a valuable diagnostic screening test in the evaluation of extracranial vascular disease.