PROBLEM TO BE SOLVED: To provide a mechanism capable of setting a dose measurement area to be used for AEC (automatic exposure control) in a short period of time.SOLUTION: A radiation imaging system comprises a radiation imaging device 140 comprising a radiation detector including a detection area in which dose detection pixels for detecting a dose of an arriving radiation 131 are arranged a first setting unit 151 that depending on an imaging part of a subject H, sets, from the detection area, a candidate area to be a candidate for a dose measurement area on which a dose of the radiation 131 is to be measured and a second setting unit 152 that on the basis of a dose detected by dose detection pixels provided in the candidate area set by the first setting unit 151 and a near-field area thereof, sets the dose measurement area.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】AEC(自動露光制御)に用いる線量測定領域の設定を短時間で行える仕組みを提供する。【解決手段】到達した放射線131の線量を検知するための線量検知用画素が配置された検出領域を有する放射線検出器を具備する放射線撮影装置140と、被検体Hの撮影部位に応じて、前記検出領域から放射線131の線量を測定する線量測定領域の候補となる候補領域を設定する第1の設定部151と、第1の設定部151で設定した候補領域及びその近傍領域に設けられている線量検知用画素で検知された線量に基づいて、前記線量測定領域を設定する第2の設定部152を備える。【選択図】図1
