An ultrasound diagnosis apparatus (1) according to an embodiment includes processing circuitry (180). The processing circuitry (180) is configured to specify a region being a part of a heart on the basis of two- or three-dimensional moving image data rendering the heart. The processing circuitry (180) is configured to obtain a reference waveform that makes it possible to estimate a cardiac phase, on the basis of the region in the moving image data specified.
