An ultrasound diagnosis apparatus includes an ultrasound probe 1, in which a plurality of transducer elements are arrayed and which converges and radiates an ultrasound on a patient and detects a reflection wave thereof, and images a tomogram of the patient, using the reflection wave, wherein an expansion detector 22 operates a difference between a radial component of a therapeutic converging beam of a movement amount of each part, and an integral amount integrated from the radial component, and extracts a tissue expansion generated at a part of the patient from the tomogram, and wherein the movement amount is calculated by performing a pattern matching between tomograms imaged with different frames.
