Doppler tissue imaging (DTI) is a new ultrasonic technique that can be used to give quantified information about the motion of the myocardium. DTI M-mode recordings can be generated that display cardiac wall motion in great detail. In order to verify the motion as displayed in these images comparisons were made with simultaneously obtained grey-scale M-mode recordings. After capturing 135 simultaneous DTI and grey-scale M-mode recordings, those were selected in which wall motion could be accurately assessed from the grey-scale recording. Comparison with the DTI images shows: (1) that DTI accurately displays the direction of wall motion; and (2) that DTI displays whether the wall is thickening or thinning as a velocity distribution across the heart wall. This information is more reliably displayed and easier to interpret in the DTI M-mode recordings than in the grey-scale M-mode recordings.