PLATELET ACCUMULATION IN CAROTID ATHEROSCLEROTIC LESIONS - SEMIQUANTITATIVE ANALYSIS WITH IN-111 PLATELETS AND TECHNETIUM-99M HUMAN-SERUM ALBUMIN

Abstract

To evaluate platelet accumulation in carotid atherosclerotic lesions semiquantitatively, a dual-tracer technique was applied, using 111In platelets and 99mTc human serum albumin. With this approach, the ratio of radioactivity in 111In platelets deposited on the vascular wall to those circulating in the blood pool, platelet accumulation index (PAI) was investigated. This study included 12 normal subjects and 25 patients with ischemic cerebrovascular disease (CVD). Angiographic abnormalities were observed at 34 of 50 carotid bifurcations in the CVD patients. The mean PAI value was significantly higher at the carotid bifurcations with angiographic abnormality than at the normal ones (P < 0.001). Elevations of mean PAI were prominent at the lesions with severe stenosis or ulceration. The degree of platelet accumulation was well demonstrated by this technique, which can also yield information on thrombogenicity and efficiency of antiplatelet therapy in carotid atherosclerotic disease.