A radiography apparatus and a method for controlling the radiography apparatus are provided. The radiography apparatus includes a radiographer configured to acquire a first radiation image of a subject before a contrast reagent is injected into the subject, and acquire a second radiation image of the subject after the contrast reagent is injected into the subject. The radiography apparatus further includes an image processor configured to calculate a difference between data of a pixel of the first radiation image and data of a pixel of the second radiation image, for each of pixels of the first radiation image, and acquire an image of the subject based the difference for each of the pixels of the first radiation image.