Radiation imaging apparatus and radiation imaging system

A radiation imaging apparatus that comprises a first scintillator, a second scintillator which receives radiation transmitted through the first scintillator, a plurality of conversion elements, and a controller, wherein

• the plurality of conversion elements include a plurality of first conversion elements and a plurality of second conversion elements with different sensitivities for detecting light emitted from at least one of the first scintillator or the second scintillator, and
• during radiation irradiation, the controller is configured to
• obtain, from a signal output from not less than one measuring element configured to measure a dose of incident radiation among the plurality of first conversion elements and the plurality of second conversion elements, a first signal corresponding to light converted from radiation by the second scintillator among the first scintillator and the second scintillator, and
• output, based on the first signal, a stop signal configured to stop the radiation irradiation to the radiation imaging apparatus, and
• after the radiation irradiation, the controller is configured to cause the plurality of first conversion elements and the plurality of second conversion elements to output signals configured to generate an energy subtraction image.