Inhomogeneous arterial wall motion at the carotid bifurcation of normal torturous arteries. This shows an example of inhomogeneous arterial wall motion at the carotid bifurcation of normal arteries with no ultrasound evidence of atherosclerotic disease. Note torturous artery with significant compression within the ICA due to posterior wall displacement. See Additional file 2 for the real-time movie of the top right image. The lower right graph displays the dilation data as a surf plot with dilation plotted as a function of the spatial position and the time.