Three-dimensional ultrasound angiography (power mode) for the quantification of carotid artery atherosclerosis

Three-dimensional (3D) ultrasound angiography was performed to diagnose carotid artery atherosclerosis. Thirty-five patients (15 women, 20 men) with a history of cerebrovascular disease were examined using conventional color-coded Doppler ultrasound and 3D ultrasound angiography. Carotid stenosis was initially diagnosed using continuous-wave Doppler ultrasound. To determine intraobserver and interobserver reliabilities, 21 patients were evaluated using 3D ultrasound on three occasions. Sixty-five percent of patients were diagnosed with stenosis of more than 50%. Twenty-two percent of plaques had a smooth surface, 72.9% were ulcerated, and 5.1% were indeterminate. Data collection for 3D imaging required 5 minutes per patient, whereas image processing and plaque volume quantification required 30 minutes. Plaque volume ranged from 0.053 to 0.685 ml. The intraobserver and inter observer variabilities were 4.16 and 5.87%, respectively (r = 0.96, p < 0.0001; r = 0.89, p < 0.0001). 3D Color Doppler and 3D ultrasound angiography assessments of plaque volume differed by 8.5%. Plaques were more precisely differentiated using 3D ultrasound, and plaque volume quantification was less affected by echo shadowing after 3D reconstruction. In comparison to other techniques for the quantification of atherosclerotic lesions, 3D ultrasound angiography offers a more precise quantitative method for prospective, clinical studies of atherosclerosis.