Ultrasound elasticity imaging method. White box indicates the region of interest (ROI) within the ultrasound image that was processed using cross correlation analyses. Arrows indicate reference axes within the ultrasound image: axial and lateral axes indicate directions parallel and perpendicular to the ultrasound beam respectively, in the plane of the ultrasound image. Elevational axis indicates direction perpendicular to the ultrasound image plane. Axial, lateral and elevational directions in the ultrasound image correspond to antero-posterior, rostro-caudal and medio-lateral anatomical directions respectively.