[Object] To improve a detection rate of a radiopaque marker on an X-ray image acquired while a tomographic image is acquired.[Solution] According to a radiopaque marker detection method of detecting the radiopaque marker disposed in a probe on multiple X-ray images captured while the probe for acquiring the tomographic image moves in an axial direction of a catheter, a position of the radiopaque marker disposed in the probe on each of the multiple X-ray images captured during the movement of the probe is detected from the X-ray images captured during a predetermined period before the probe starts to move, by extracting a line extending along the probe and using the extracted line.
