PROBLEM TO BE SOLVED: To provide a medical image processor capable of reducing a work load for displaying an area including a culture cell piece, a medical image processing method, a medical image diagnostic apparatus, and a culture cell piece manufacturing method for producing a culture cell piece.SOLUTION: A medical image processor includes a storage part for storing volume data on a subject to which a culture cell piece provided with a marker is transplanted, a marker area detection part for detecting a marker area of the marker from the volume data by threshold processing, an image generation part for generating an image that visualizes an area including the marker area from the volume data, and a display part for displaying the image.
