Apparatus and method of medical diagnostic imaging. The apparatus includes: an image unit for constructing volume image data by capturing images from a multiplicity of tomographic images of a sampling specimen and for constructing internal three dimensional images of the diagnosing object of the sampling specimen as seen from a viewing point a display for displaying the three-dimensional images an input unit for entering parameters for setting up a precutting plane at an inter-voxel image data boundary between voxel image data of the volume image data closer to the viewing point than the diagnosing object and voxel image data associated with the diagnosing object and a control unit for controlling the structure of the three-dimensional images constructed by the image unit based on the precutting plane set up via the input unit, wherein the control unit extracts a boundary based on one of the parameters inputted to the input unit.