Measurement of carotid artery stenosis: correlation analysis between B-mode ultrasonography and contrast arteriography

Purpose: To evaluate the efficacy of B-mode ultrasonography (US) in measurement of carotid stenosis% (CS%). Methods: One hundred and thirth-three carotid arteries in 96 patients who underwent both carotid US and carotid arteriography (CA) were included in this retrospective study. To measure CS% on US, a cross sectional view of the most stenotic segment of the internal carotid artery was captured and residual diameter and original diameter of that segment were measured with electronic caliper on the same plane and in the same direction. To measure CS% on an angiogram, we used European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Pearson's correlation analysis and linear regression analysis were used to determine the correlation between CS% on an US and angiogram. Results: Pearson's correlation coefficient (R) between CS% measured in US and CA were 0.853 (ECST method, P < 0.001) and 0.828 (NASCET method, P < 0.001). Accuracies of B-mode US were 93.2%, 88.0%, and 81.2% for estimating CS% by ECST method and 86.5%, 82.7%, and 82% for estimating CS% by NASCET method. Conclusion: CS% measured in B-mode US was simpler and showed a strong positive correlation with that measured on an arteriogram either ECST or NASCET method.