Figure 6

A whole-image speckle tracking example. A rectangular grid of equidistantly placed ROIs was specified over the whole image plane, as seen in (a). There is a 12 × 12 grid in (a) for clarity, but in the analysis a 100 × 100 grid was used. (b) illustrates a frame at a later point in time; it is clear that the ROIs have repositioned due to the tissue movements. The red ROIs in (a) and (b) are positions that were tracked badly, in this case they went outside of the right border of the image. The PCA score plot in (c) is found from the two-way matrix created by putting the coordinates of the ROIs as variables in the columns and the time (the frames) in the rows. Note the close resemblance to Figure 5(b).