Evolutionary trends in carotid atherosclerotic plaques: results of a two-year follow-up study using an ultrasound imaging system.

A two-year follow-up on 118 atherosclerotic lesions of the extracranial carotid tract observed in 70 patients was carried out using real-time high-resolution echotomography. The following plaque characteristics were monitored: the echogenic patterns (soft, intermediate, hard, and mixed), the surface aspects, and the degree of stenosis. The aim of the study was to evaluate plaque evolution, in relation both to the degree of vessel stenosis produced and to the echostructural characteristics of the lesion. After two years 68% of the lesions remained unchanged while the degree of vessel stenosis increased in 32%; no case of regression was observed. Intrinsic factors appearing to condition an increase in degree of stenosis were "mixed" and "hard" echogenic pattern, an irregular lesion surface, and an initial degree of stenosis of more than 50%. A modification in the echogenic pattern, which generally tended to progress toward more highly reflecting echogenic levels was observed in 27% of the lesions studied.