Ultrasonograph

Patent Granted An ultrasonograph comprises a transmitting section (102) for driving an ultrasonic probe to transmit ultrasound to a measurement region of a subject including an artery vessel wall, a receiving section (101) for receiving reflected waves produced when the ultrasound is reflected from the subject by means of the ultrasonic probe to generate a reception signal, a movement information calculating section (110) for calculating movement information at least in the axial direction of the artery vessel wall from the reception signal, and a boundary position determining section (109) for determining the position of at least one of the blood flow-inner membrane boundary, the media-outer membrane boundary, and the outer membrane-body connective tissue boundary of the artery vessel wall in the measurement region according to the movement information.