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

Background and Purpose-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. Methods-We investigated 17 arteries with poor precontrast investigation conditions and suspected high-grade stenosis or occlusion by contrast-enhanced ECCD. Results-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. Conclusions-Echocontrast-enhanced ECCD of the carotid arteries is helpful for stenosis classification in a small group of preselected patients with poor original examination conditions.