Fig. 8.

The centroid distributions from 100 images of a focused beam in different media. Panels (a)-(f) illustrate how the motions of a focused beam are randomized in all directions when the imaging duration is sufficiently long (see Figs. 6 and 7). For water and phantoms, the imaging duration is 100 ms (100 images acquired at a 1-ms integration time); for tissues, the imaging duration is 1 sec (100 images acquired at a 10-ms integration time). Blue dots represent the positions of the unperturbed beam in different types of media.