Anisotropic edge-preserving smoothing in carotid B-mode ultrasound for improved segmentation and intima-media thickness (IMT) measurement

Non-invasive B-mode ultrasound imaging of carotid artery intima-media thickness (IMT) is used for estimation of the atherosclerotic burden. Image interpretation and measurement is degraded by imaging noise and other artifacts. Edge detection based on local estimation of image gradient produces irregular boundaries and poor IMT estimates under such conditions, Manual tracing produces smoother borders but is labor-intensive and exhibits poorer intra and inter-observer reproducibility. We present a new non-linear segmentation algorithm that uses global image information to improve border delineation, simplify image frame selection and improve IMT measurement We demonstrate examples of image enhancement and evaluate the measurement reproducibility of this method in 40 carotid data sets from an ongoing clinical study