1. A method for imaging a portion of a body of a subject that undergoes motion, the method comprising: acquiring a plurality of image frames of the portion of the subject's body; and generating a stream of image frames in which a vicinity of a given feature of the image frames is enhanced, by: automatically identifying the given feature in each of the image frames, aligning the given feature in two or more image frames of the plurality of image frames, averaging sets of two or more of the aligned frames to generate a plurality of averaged image frames, and displaying as a stream of image frames the plurality of averaged image frames.