THREE-DIMENSIONAL ULTRASOUND QUANTIFICATION OF INTENSIVE STATIN TREATMENT OF CAROTID ATHEROSCLEROSIS

This study was designed to evaluate 3-D ultrasound (3DUS)-derived vessel wall volume (VWV), a 3-D measurement of the carotid artery intima and media, including atherosclerotic plaque, in patients enrolled in a randomized placebo-controlled three-month study of intensive atorvastatin treatment. Thirty-five subjects with carotid stenosis >60% who provided written informed consent and completed a randomized, double-blind, placebo-controlled study were evaluated at baseline and at three months after receiving either 80 mg atorvastatin (16 subjects, nine male, mean age 68 +/- 8.6 y) or placebo (19 subjects, 15 male, mean age 70 +/- 9.4 y) daily. 3DUS images were acquired and 3DUS VWV was manually segmented by a single observer. Individual lumen and wall segmentation contours were also used to generate carotid atherosclerosis thickness difference maps by establishing correspondence between points along the vessel wall and lumen segmentation contour surfaces, and digitally subtracting registered baseline and follow-up thickness maps. 3DUS VWV increased by 70 +/- 140 mm(3) (+4.9 +/- 10.3%) in the placebo group and decreased by 30 +/- 110 mm(3) (-1.4 +/- 7.7%) in the atorvastatin group (p <0.05). Two-dimensional maps generated from the VWV measurements show localized heterogeneity and vessel wall thickness changes for all subjects, mainly in the common carotid artery. Carotid 3DUS VWV is a quantitative measure of atherosclerosis burden including the intima, media and plaque, with sensitivity to detect changes over short periods of time. Quantitative VWV thickness difference maps provide visual evidence of the spatial and temporal dynamics of carotid artery changes. (E-mail: gep@imaging.robarts.ca) (C) 2009 World Federation for Ultrasound in Medicine & Biology.