This International Standard is applicable to medical-diagnostic, ultrasonic shear-wave elastography systems, exciting (internally or externally) shear waves and tracking their propagation within biological tissue. This International Standard establishes: " In part 1, a list of quantities and parameters, which must be provided to the user, many in the image headers. Note 1: The first edition of the standard focuses on liver applications of shear-wave elastography, but does not exclude its application to other organs (e.g. breast, thyroid, prostate, kidney, muscle).