Stationary clutter rejection in echocardiography.

Clutter is one of the most problematic artifacts in echocardiography. It sometimes blocks substantial portions of the image, making the diagnosis in these areas difficult, if not impossible. This is, to our knowledge, the first study aimed solely at automatic clutter rejection, performed in postprocessing, without changing the data-acquisition method. The procedure is based on the fact that the motion of the organs causing most of the clutter (e.g., the ribcage and the lungs) is much slower than that of the cardiac muscle, so that the clutter shows very small changes during a single cardiac cycle. The algorithm has been successfully tested on a set of 16 cineloops in apical two-chamber and apical four-chamber views, belonging to 16 different patients. The results show a high probability of clutter detection, while maintaining a low probability for erroneous detection of pixels as clutter.