Atherosclerotic plaque at the carotid artery bifurcation. Correlation of ultrasonographic imaging with morphology.

Morphologic characteristics of atherosclerotic plaque at the carotid artery bifurcation were compared to the appearance of the plaque on real-time B-mode ultrasonography. Mural plaques propagating along the wall of the carotid sinus had a 72% frequency of recent organizing hemorrhage. Nodular plaques causing local narrowing of the vessel had only a 23% incidence of organizing hemorrhage. This difference was significant (P less than 0.01). The presence of recent organizing hemorrhage in mural plaques may account for the increased frequency of symptoms previously observed to occur ipsilateral to mural plaques compared to nodular plaques.