Accuracy of Carotid Artery Stenosis Quantification with 4-D-Supported 3-D Power-Doppler versus Color-Doppler and 2-D Blood Velocity-Based Duplex Ultrasonography

Assessment of the severity of internal carotid artery stenosis is relevant to therapeutic decisions. Direct measurement of stenosis in static three-dimensionally rendered ultrasonographic color-Doppler images after an orientation with 4-D gray-scale views (4D/3D-C-US) was recently observed to be metrically non-inferior to angiography. In the study described here, power-Doppler (Christian Doppler was a physicist) ultrasonography (4D/3D-P-US) was prospectively compared with angiography, 4D/3D-C-US and 2-D duplex ultrasonography (DUS) in a similar fashion using blinded observers. Percentage stenosis was measured in 36 patients. Continuous percentage stenosis measures (standard deviation of difference and concordance correlation coefficient) between angiography and 4D/3D-P-US did not differ from the results between angiography observers (p > 0.05). Dichotomous diagnosis with 4D/3D-P-US resulted in κ values similar to the inter-rater agreement of angiography and the inter-method agreement of 4D/3D-C-US and DUS compared with angiography. Binary accuracy did not differ between 4D/3D-P-US, 4D/3D-C-US and DUS (p > 0.5). In conclusion, stenosis grading using 4D/3D-P-US exhibited non-inferior inter-method agreement with angiography at good accuracies, similar to 4D/3D-C-US and DUS.