Plaque imaging of the internal carotid artery - correlation of B-flow imaging with histopathology

The noninvasive identification of plaque types prone to cause symptomatic disease is of great interest to improve the effectiveness of surgical or interventional management. The purpose of the present prospective pilot study was to evaluate the association between the results of imaging-the novel sonography technique B-flow imaging (BFI), B-mode, and color Doppler imaging (CDI)-and histopathologic examination in the characterization of internal carotid artery (ICA) plaques.

Twenty-eight consecutive patients with high-grade internal carotid artery stenosis scheduled for carotid endarterectomy were included. BFI, B-mode, and CDI images were used to classify the plaques applying the standardized scores of Beletsky et al and the American Heart Association (AHA), to calculate the gray-scale median (GSM) and to detect potential ulcerations; histopathologic examination results of explanted plaques served as the "gold standard."

Based on the classification of Beletsky et al, BFI and histopathologic examination results agreed in 21 (75%, kappa = 0.61, P < .001) patients, and the corresponding results for B-mode were 19 (68%, kappa = 0.52, P < .001) patients, respectively. Corresponding results for the AHA classification revealed inferior agreements for BFI (19 patients/68%, kappa = 0.38, P = .003) and B-mode (17 patients/61%, kappa = 0.25, P = .045). The median GSM for BFI and B-mode correlated significantly (r = 0.95, P < .001). The sensitivity of BFI for the detection of ulcerated plaques was 100% and the specificity was 95.8%; corresponding values for CDI were 100% and 92.7%, respectively.

BFI and the combination of B-mode and CDI exhibit comparable results in the assessment of ICA plaque components and plaque ulceration as well as in the determination of GSM levels.