Carotid artery stenosis: gray-scale and Doppler ultrasound diagnosis. Society of Radiologists in ultrasound consensus conference

Abstract

Conclusion: A consensus conference convened by the Society of Radiologists in Ultrasound developed a set of criteria for grading internal carotid artery (ICA) stenosis with Doppler ultrasound scanning. Criteria are based primarily on ICA peak systolic velocity (PSV) and demonstration of presence of plaque on gray-scale and color Doppler scans. Summary: A multidisciplinary panel was charged to develop a set of reasonable criteria for Doppler diagnosis of ICA stenosis. Criteria proposed were based on review of the literature and presentations at the conference. Recommendations included: 1Use of gray-scale, color Doppler scanning and spectral Doppler ultrasound scanning for all carotid artery examinations2Stratification of ICA stenoses into six categories: a.Normal: ICA PSV less than 125 cm/s, with no visible plaque or intimal thickeningb.Less than 50% stenosis: ICA PSV less than 125 cm/s, with visible plaque or intimal thickeningc.50% to 69% stenosis: ICA PSV 125 to 230 cm/s, with visible plaqued.ICA stenosis greater than 70% to near occlusion: ICA PSV greater than 230 cm/s, with visible plaque and luminal narrowing on gray-scale and color imagese.Near occlusion: color Doppler scan showing an extremely narrow lumenf.otal occlusion: no detectable lumen on gray-scale ultrasound scans and no flow on color, power, or spectral Doppler scans ICA–common carotid artery PSV ratio and ICA end-diastolic velocity may also be used when it appears that ICA PSV may not represent the extent of stenosis. Comment: The conference consisted of panelists from radiology, neurology, vascular surgery, vascular medicine, and interventional radiology, among other specialties. Results represent what the panelists considered to be reasonable criteria for ICA stenosis. It is suggested that these criteria be considered by laboratories with insufficient angiographic material for validation of existing published criteria. The proposed criteria have not been tested, and do not represent the results of any single publication. Laboratories using published criteria validated locally are urged to continue to use them.