PROBLEM TO BE SOLVED: To generate and display navigation image data effective in treating a septal defect hole.SOLUTION: This medical image processor 100 includes a navigation data generating part 1 for generating, as navigation data, a safety region to a catheter distal end inserted into a heart chamber and at least one of the suitable insertion direction and insertion timing of the catheter distal end to the septal defect hole in a heart chamber wall based on volume data collected beforehand from a patient a navigation image data generating part 2 generating navigation image data by superimposing the navigation data on X-ray image data collected by radiographing the patient with the catheter distal end inserted and a display part 3 for displaying the navigation image data.
