Carotid Artery Stenosis: Gray-Scale and Doppler US Diagnosis—Society of Radiologists in Ultrasound Consensus Conference

Abstract

The Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts in the field of vascular ultrasonography (US) to come to a consensus regarding Doppler US for assistance in the diagnosis of carotid artery stenosis. The panel's consensus statement is believed to represent a reasonable position on the basis of analysis of available literature and panelists' experience. Key elements of the statement include the following: (a) All internal carotid artery (ICA) examinations should be performed with gray-scale, color Doppler, and spectral Doppler US. (b) The degree of stenosis determined at gray-scale and Doppler US should be stratified into the categories of normal (no stenosis), <50% stenosis, 50%-69% stenosis, > or =70% stenosis to near occlusion, near occlusion, and total occlusion. (c) ICA peak systolic velocity (PSV) and presence of plaque on gray-scale and/or color Doppler images are primarily used in diagnosis and grading of ICA stenosis; two additional parameters, ICA-to-common carotid artery PSV ratio and ICA end-diastolic velocity may also be used when clinical or technical factors raise concern that ICA PSV may not be representative of the extent of disease. (d) ICA should be diagnosed as (i) normal when ICA PSV is less than 125 cm/sec and no plaque or intimal thickening is visible; (ii) <50% stenosis when ICA PSV is less than 125 cm/sec and plaque or intimal thickening is visible; (iii) 50%-69% stenosis when ICA PSV is 125-230 cm/sec and plaque is visible; (iv) > or =70% stenosis to near occlusion when ICA PSV is greater than 230 cm/sec and visible plaque and lumen narrowing are seen; (v) near occlusion when there is a markedly narrowed lumen at color Doppler US; and (vi) total occlusion when there is no detectable patent lumen at gray-scale US and no flow at spectral, power, and color Doppler US. (e) The final report should discuss velocity measurements and gray-scale and color Doppler findings. Study limitations should be noted when they exist. The conclusion should state an estimated degree of ICA stenosis as reflected in the above categories. The panel also considered various technical aspects of carotid US and methods for quality assessment and identified several important unanswered questions meriting future research.

Carotid Atherosclerosis Detected by Ultrasonography: A National Cross‐Sectional Study

“…Plaque was defined as IMT ≥1.5 mm or focal narrowing of the vessel wall of >50% relative to adjacent segments. Stenosis severity was classified into the following categories: normal (no stenosis), <50%, 50% to 69%, 70% to 99%, and occlusion 15. Moderate stenosis was defined as 50% to 69% stenosis and severe stenosis as ≥70% stenosis.…”

Increased Levels of Lectin‐Like Oxidized Low‐Density Lipoprotein Receptor‐1 in Ischemic Stroke and Transient Ischemic Attack

“…In 81 patients, both blood samples and carotid plaques obtained at the same time point were available. The carotid stenosis and plaque echolucency were classified by precerebral color triplex ultrasound and computed tomography angiography according to consensus criteria 11, 12. Exclusion criteria were concomitant infections, connective tissue disease, heart failure, malignancies, as well as kidney and liver disease.…”

Prevalence of Carotid Plaque in a 63‐ to 65‐Year‐Old Norwegian Cohort From the General Population: The ACE (Akershus Cardiac Examination) 1950 Study

“…Carotid artery stenosis severity was assessed in accordance with Consensus Panel gray scale and Doppler US criteria13; peak velocity <125 cm/s was considered normal, 125 to 230 cm/s showed 50% to 69% stenosis, and >230 cm/s showed >70% stenosis.…”