Figure 1

homogeneous arterial wall motion of a normal CCA segment. The region of interest (ROI) is positioned over a straight longitudinal section of the CCA proximal to the carotid bulb. The wall displacements along the artery are superimposed on a magnified graphic scale relative to the initial baseline dilation reference positions (yellow lines). The green lines map the vessel walls of each image frame, based on an edge detection algorithm using the 2D image information. The middle image shows the maximum (orange line) and minimum (green line) displacements within the cardiac cycle selected by the red vertical line in the bottom image. The bottom image shows the spatial wall displacements as a function of time, showing the dilation curves for each scan line (approximately 200 lines, separated by 0.148 mm). The blue vertical lines indicate the start of each cardiac cycle. The orange dilation curves correspond to the mean wall displacements in the ROI. The top right figure shows the wall displacements for the selected cardiac cycle, highlighting in yellow the wall displacements at the location selected by the vertical red line in the ultrasound image.