According to one embodiment, an ultrasonic diagnosis apparatus includes an ultrasonic probe, an ultrasonic transmission/reception unit, a volume data generating unit, a projected image generating unit, a two dimensional region-of-interest setting unit, a specifying unit, a calculation unit and a three-dimensional region-of-interest determination unit. The specifying unit specifies cells on rays which pass through the respective pixels in the 2D-ROI and are used to acquire a VR image. The calculation unit calculates the contribution degree of each cell based on the voxel value and opacity of each cell specified and calculates the average value of the contribution degrees of cells equal in distance from the screen of the VR image along the line-of-sight direction. The three-dimensional region-of-interest determination unit specifies the distances from the screen of the VR image which correspond to average contribution values exceeding the predetermined threshold and determines the position of the 3D-ROI in the volume data.
