New Technologies to Determine Carotid Plaque Vulnerability in Patients With Significant Carotid Plaques

Subjects will receive a low mechanical index (0.17-0.20) imaging during ultrasound contrast agent intravenous infusion. Real-time cine-loop including longitudinal and transverse images obtained at least 3 seconds before and 5 minutes after the appearance of the contrast effect in the lumen of the carotid artery will be acquired and digitally stored for offline analysis. Also use of a 3D ultrasound transducer to evaluate the feasibility of using US images with contrast to assess the residual diameter of the diseased vessel. Specifically, two 3D acquisitions of each lesion would be obtained after contrast has been injected.

Shear wave elastography will be performed with the General Electric Logiq E9 scanner acquiring images of each plaque in the longitudinal and transverse imaging planes. In each plane 10 measurements will be made and the in-phase/quadrature (IQ) data will be saved for further analysis. The plaque area in the imaging plane will be user-defined to extract the wave velocity values for a ROI analysis.

A standard carotid US examination using Duplex imaging will performed using a linear array transducer to obtain longitudinal and transverse images. All ultrasound measurements will be made by a trained registered vascular technologist. Severity of stenosis of the plaque will be measured based on established protocol and guidelines.