Local arterial wall motion stiffening around a mild stenosis calcified plaque. This shows an example of arterial wall motion across a calcified plaque with a mild 30% stenosis (diameter reduction). Note the localised stiffening and high dilation gradients. See Additional file 3 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.