Medical image processing apparatus and X-ray CT apparatus

An X-ray CT apparatus comprising:

• an X-ray tube configured to emit X-rays to a region of a subject that has a joint formed between three or more bones;
• a detector configured to detect X-rays that have passed through the region of the subject;
• image reconstruction circuitry configured to reconstruct three-dimensional medical image data based on detection data of the X-rays detected by the detector;
• and
• processing circuitry configured to
• detect the three or more bones and a joint space region from the three-dimensional medical image data, the joint space region corresponding to a joint space of the joint,
• divide the joint space region into a plurality of small regions corresponding to each of different pairs of opposed bones between which each of the small regions is present, the different pairs of opposed bones being chosen from the three or more bones,
• assign pair information indicating the different pairs of opposed bones between which each of the small regions is present to the joint space region,
• obtain information on each of the small regions based on the small regions into which the joint space region has been divided that correspond to the different pairs of bones, the obtained information including the pair information, and
• output the obtained information, wherein
• the processing circuitry is further configured to detect temporal change of the joint space region with respect to multiple frames of the three-dimensional medical image data captured in a time sequence in a single main imaging, and obtain the information on each of the small regions with respect to the multiple frames.