Po-Thur Eve General-20: A Novel Non-Invasive 3D Ultrasound Imaging Phenotype of Carotid Atherosclerosis

Abstract

Atherosclerosis — a chronic, inflammatory disease involving the development of atherosclerotic lesions in the major vessels of the vasculature is the major underlying cause of cardiovascular disease. To better understand how and where carotid atherosclerosis changes occur when plaques progress and regress, we are validating a new phenotype of carotid atherosclerosis — the measurement of carotid vessel wall volume (VWV). This measurement can be applied to understand local plaque volume changes in human subjects. Five research subjects with carotid plaque area ⩾ 0.5 cm2 were studied. 3D USimages were acquired for the left and right carotids of each subject. VWV measurements were carried out using 3D Quantify Software and repeated five times by a single observer, with a minimum of two days between each measurement repetition. The observer stepped transversely through the image volume in 1mm increments, manually tracing vessel and lumen boundaries. VWV was calculated by subtracting the total lumen volume from the total vessel volume. A correspondence map was established between reconstructed vessel and lumen surfaces; the distance between each pair of correspondence points was estimated to be plaque thickness. These atherosclerosis plaque thickness maps generated from vessel wall volume segmentations allow us to visualize plaque thickness distribution and plaque topology along the length of the carotid vessel. In longitudinal studies evaluating plaque progression or regression, this technique should allow for the generation of topology difference maps between time points. These difference maps can provide new information regarding local plaque changes at specific points along the carotid vessel.