Echocontrast-enhanced ultrasound of extracranial internal carotid artery high-grade stenosis and occlusion.

Abstract

Proper assessment of extracranial internal carotid artery high-grade stenosis and occlusion by extracranial color-coded duplex sonography (ECCD) is occasionally made difficult by shadowing, an unfavorable insonation angle, low flow velocity or volume, or a deep insonation depth. In these cases, echocontrast could be helpful to quantify the degree of stenosis and to diagnose occlusion. We investigated 17 arteries with poor precontrast investigation conditions and suspected high-grade stenosis or occlusion by contrast-enhanced ECCD. Compared with the precontrast scans, echocontrast allowed for significantly more segments to be evaluated by pulsed Doppler sonography (P<0.001) and for longer lumen segments to be displayed on color mode (P<0.001). Because it was now possible to place the sample volume right into the jet of the stenosis, the maximal flow velocity registered increased in all patients with stenosis. Echocontrast-enhanced ECCD of the carotid arteries is helpful for stenosis classification in a small group of preselected patients with poor original examination conditions.