a) anatomical and b) velocity image at endsystole (heart phase 11); c) anatomical and d) velocity image at diastole (heart phase 6). In both velocity images the velocity twist is visible. In b) the velocity direction of the apical heart is counterclockwise in respect to the short axes geometry and the basal velocity is vice versa. In d) the velocity direction is changed. 1e) displays the angle of the myocardial free wall, by which it is rotated. Red: basal rotation; green: apical rotation; yellow: equatorial rotation and blue: twist angle = phiapical - phibasal.