Development of 3D ultrasound techniques for carotid artery disease assessment and monitoring

Background Quantitative measurements of carotid plaque burden are used to monitor patients and evaluate established interventions as well as new treatment options. Purpose Three-dimensional ultrasound (3D US) techniques were developed to noninvasively monitor the progression of carotid artery disease in both symptomatic and asymptomatic patients. Methods Three-dimensional carotid US images were acquired and reconstructed, and methods for quantitative assessment were developed. The measurement of intimamedia thickness (IMT) based on two-dimensional ultrasound (2D US) images was extended to a 3D vessel-wall-plus-plaque thickness (VWT), obtained by computing the distance between the carotid wall and lumen surfaces on a point-by-point basis. VWT measurements were superimposed on the arterial wall to produce 3D VWT maps. VWT changes were determined by comparing the 3D VWT maps obtained at two different time points. To facilitate the visualization and interpretation of the VWT and VWT-Change maps, a technique to flatten these maps was developed. Results Carotid remodeling involving changes in both arterial wall and plaque thickness was assessed with VWT maps obtained from in vivo 3D ultrasound images. Conclusion 3D carotid ultrasound image evaluation with VWT mapping provides a feasible means for the analysis of plaque burden volumes and changes.