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; and processing circuitry configured to: generate a plurality of frames of fluoroscopic images of an object on a basis of the detected X-rays in sequence, detect a first calcified region on each of the fluoroscopic images in sequence, superimpose a calcified region image on a position of the first calcified region on each of the fluoroscopic images in sequence, the calcified region image including a second calcified region on a pre-acquired CT image or MR image of the object, display resulting images on a display device in sequence, and notify a user on a basis of a position of a medical instrument inserted into the object and the position of the first or second calcified region.