Radiation imaging system and method for controlling the same

A radiation imaging system which performs a difference process using a mask image which is instructed by a calculation unit to be stored in a storage unit and which is based on a radiation image which is obtained before a contrast agent is injected by an injection device to a certain portion of an object and which is selected from among fluoroscopic images obtained by a radiation imaging apparatus on the basis of a radial ray which is irradiated by a radiation source and which passes the certain portion, and a radiation image which is obtained after the contrast agent is injected and which is selected from among the fluoroscopic images, the radiation imaging system comprising:

• a controller configured to display a first graphic representing a first timing when irradiation of a radial ray from the radiation source is started, a second graphic representing a second timing when the mask image is stored, and a third graphic representing a third timing when injection of the contrast agent performed by the injection device is started in a display unit in this order along a time axis displayed in the display unit, control the second timing by a position of the second graphic relative to the time axis, and control the third timing by a position of the third graphic relative to the time axis,
• wherein, when one of the second and third graphics is moved along the time axis, the controller moves the other of the second and third graphics such that an interval between the first and third graphics becomes larger than an interval between the first and second graphics.