1. An X-ray diagnostic apparatus comprising: an X-ray emitting device configured to generate X-rays; an X-ray detection device placed facing the X-ray emitting device and configured to detect the X-rays; a fluoroscopic image generating unit configured to generate a plurality of frames of fluoroscopic images of an object on a basis of the detected X-rays in sequence; a calcified region detection unit configured to detect a calcified region on each of the fluoroscopic images in sequence; and a display control unit configured to superimpose a calcified region image on a position of the calcified region on each of the fluoroscopic images in sequence, the calcified region image including a calcified region on a pre-acquired CT image or MR image of the object, and to display resulting images on a display device in sequence.