Evaluation of carotid artery plaques with B-flow sonography and comparing the results with color, power doppler US and DSA

PURPOSE: To evaluate carotid artery lesions with B-flow sonography and compare the findings with color, power Doppler sonography and digital subtraction angiography (DSA). MATERIALS AND METHODS: Forty-Three patients (30 male, 14 female; mean age 64±9.2; age range: 42-81) with 61 carotid artery lesions were involved in the study. The lesions were evaluated with color, power Doppler and B-flow sonography. All images were reviewed and graded independently by two radiologists for surface delineation, plaque morphology and overall image quality. The grades for each technique were compared with Friedman and Wilcoxon tests. Simple regression analysis was used to compare the percentage of stenosis calculated with different sonographic techniques and DSA for lesions causing more than 50 % stenosis. RESULTS: Statistical analysis with Friedman test revealed that B-flow is superior to other sonographic techniques for all three parameters (plaque surface delineation, plaque morphology and overall image quality). Wilcoxon test also showed B-flow is superior to other methods for the evaluation of plaque surface delineation and plaque morphology (p=0.000); while no significant difference was found between B-flow and power Doppler imaging for the evaluation of overall image quality (p=0.09). Kappa scores reflected moderate to good interobserver correlation (0.297-0.659). The percentage of stenosis calculated with both B-flow and power Doppler sonography correlated with DSA significantly (p=0.000). CONCLUSION: B-flow sonography is a technique which provides direct visualization of the blood echoes and the morphology of the surrounding vessel wall simultaneously. This technique maintains more efficient evaluation of carotid artery lesions by eliminating artifacts such as aliasing and overwriting.