Typical speckle pattern in the myocardium. The two enlarged areas show completely different speckle patterns, which is due to the randomness of the interference. This creates a unique pattern for a selected region that can recognized and hence, the displacement of the region in the next frame can be identified. When the speckle pattern is followed by M-mode in the wall, the alternating bright and dark lines remain to a large degree unbroken, showing the pattern to be relatively stable, with the speckles moving along with the true myocardial motion; the myocardial motion can therefore be tracked by the speckles.