Ultrasonic imaging methods are described for eliminating the effects of physiological motion such as respiratory motion from image data of a sequence of images which is to be used for quantified analysis such as time-intensity curve computation. A bright reflector in the images of the loop which exhibits motional effects such as cyclical variation in brightness or position from image to image is identified and its variation used to identify cycles of motion. A phase or range of phases of the cycles is identified. Images acquired during the identified phase or phase range of the motion cycles during the loop are then used for quantified processing.