3D is better than 2D ultrasound in differentiating between symptomatic and asymptomatic plaques

Abstract

Purpose: Up to 30% of ischemic strokes are caused by Carotid Artery Disease. Currently the indication for surgery is based on degree of stenosis which does not take into account the morphology of the atherosclerotic plaque. Certain histological features are associated with risk of stroke, the so called “vulnerable” plaque. Studies have shown that ultrasound may be able to identify vulnerable plaques. Most assessments use 2D ultrasound (US). Some of the latest involve 3D US. There have been few studies that compare 2D with 3D ultrasound. Methods: Twelve carotid plaques (From 5 asymptomatic and 7 symptomatic patients), removed at the time of carotid endarterectomy, were assessed with both a 3D linear array and a 2D US probe. US images were analysed and compared with histological slides of the same sections in order to assess plaque volume and the percentage occupied by lipid. 3D and 2D US results were compared. Results: 3D US accurately predicted the histological lipid volume and percentage. 3D US was able to differentiate between symptomatic and asymptomatic plaques (P= 0.047) with 100% sensitivity, 60% specificity. Neither 2D nor 3D ultrasound were able to predict risk of stroke. Conclusion: Ex-vivo 3D US using grey-scale median, can differentiate between symptomatic and asymptomatic plaques. With further research, is may be possible to use 3D US to help refine the indication for recommending carotid endarterectomy.