Detection of early atherosclerotic lesions in the carotid artery: Experimental and preliminary human data

Abstract

There is a strong need to directly image, noninvasively, atheromatous lesions for early lesion detection, serial assessment of the presence and extent of disease, and treatment monitoring of atherosclerosis. The aim of this study was to investigate the value of polyclonal¹¹¹Inhuman IgG (¹¹¹In-HIG) in human carotid artery disease. A comparative study between¹¹¹In-HIG and¹²⁵I-LDL uptake in atheromatous lesions was also performed in 12 cholesterol-fed New Zealand white rabbits. Ultrasonographic and scintigraphic findings in 58 patients were compared. HIG was labeled with 500 μCi¹¹¹Indium by the diethyleneaminepentaacetic anhydride (DTPA). After injection of 10 μCi¹²⁵I-LDL, the respective entry into aortic segments was evaluated in the animals.¹¹¹In-HIG accumulation was higher in reendothelialized areas, foam cells, at the edge of lesions, and in hyperlipidemic rabbits. Ultrasound examinations of the carotid arterial wall showed wall thickening in 45 patients and plaques in 44 patients. Scintigraphic imaging of the identical area provided increased uptake in 40 patients and no abnormal uptake of ¹¹¹In-HIG in 18 patients. There was, however, no significant correlation between the radiotracer retention and the ultrasonographic findings or laboratory and clinical parameters. The data provide evidence that the two imaging techniques for early atherosclerotic lesions are visualizing different aspects of atherogenesis: the functional (HIG) on the one side, and the morphological (ultrasonography) on the other side.