PROBLEM TO BE SOLVED: To provide a medical image diagnostic apparatus which allows a user to observe the same position of an organ by matching the position and orientation of the organ.SOLUTION: The medical image diagnostic apparatus includes: an imaging section for detecting radiation rays passing through an analyte to collect projection data a detection section for detecting biological information periodically changing which is emitted from the analyte a scanning control section for controlling the imaging section synchronously with the biological information an image processing section for extracting at least two feature points from each piece of volume data acquired by processing the projection data, detecting an axis line connecting the two feature points and a direction vector starting from the axis line, converting coordinates of multiple pieces of volume data which continue with time so that reference coordinates of a portion of interest set on the axis line and the direction vector match each other and generating a cross sectional image passing through the reference coordinates of each piece of volume data and a display section for displaying an image processed by the image processing section.
