Radiation imaging system and operating method thereof, and radiation image detecting device

An operating method of a radiation imaging system including an x-ray or γ-ray radiation source for emitting x-ray or γ-ray radiation to an object;

• an x-ray or γ-ray radiation image detecting device having an x-ray or γ-ray detection panel formed with an imaging surface for imaging a radiographic image of said object, said imaging surface having an array of a plurality of pixels each for accumulating electric charge in accordance with a received dose of said radiation emitted from said radiation source;
• a plurality of dose detection sensors disposed in said imaging surface, for detecting said received dose;
• and an automatic exposure control unit for performing automatic exposure control by which emission of said radiation from said radiation source is stopped based on a comparison result between an integrated value of said received dose detected by said dose detection sensor and a predetermined emission stop threshold value in order to control exposure of said radiographic image, said operating method comprising:
• an expected received dose obtaining step for obtaining an expected received dose that is expected to be applied to a part of said imaging surface;
• an area determining step for determining a measurement area used in performing said automatic exposure control, out of said imaging surface based on a comparison result between said expected received dose and said received dose detected by said dose detection sensor, said measurement area being set at a region of interest in making a diagnosis;
• and
• an automatic exposure controlling step for performing said automatic exposure control by using said dose detection sensor situated in said measurement area,
• wherein said area determination step is performed after said radiation source starts emitting said radiation and said received dose comes to a constant value.

An x-ray or γ-ray radiation image detecting device comprising:

• an x-ray or γ-ray detection panel formed with an imaging surface for imaging a radiographic image of an object, said imaging surface having an array of a plurality of pixels each for accumulating electric charge in accordance with a received dose of x-ray or γ-ray radiation emitted from an x-ray or γ-ray radiation source;
• a plurality of dose detection sensors disposed in said imaging surface, for detecting said received dose;
• an expected received dose obtainment unit for obtaining an expected received dose that is expected to be applied to a part of said imaging surface;
• an area determination unit for determining a measurement area out of said imaging surface based on a comparison result between said expected received dose and said received dose detected by said dose detection sensor, said measurement area being used in performing automatic exposure control that makes said radiation source stop emitting said radiation to control exposure of said radiographic image and said measurement area being set at a region of interest in making a diagnosis;
• and
• an automatic exposure control unit for performing said automatic exposure control based on a comparison result between an integrated value of said received dose detected by said dose detection sensor situated in said measurement area and a predetermined emission stop threshold value,
• wherein said area determination unit performs area determination after said radiation source starts emitting said radiation and said received dose comes to a constant value.