1. A radiation detecting element comprising: a plurality of pixels disposed in a matrix in a common detection region that detects radiation, each pixel including a sensor portion that generates charges based on irradiation of radiation or on illumination of light that has been converted from radiation, and a switch element configured to read out the generated charges; a plurality of first scan lines, connected to the switch elements included in pixels that are employed as radiographic imaging pixels out of the plurality of pixels, through which control signals for switching the switch elements flow; a plurality of second scan lines, connected to the switch elements included in pixels that are employed as radiation detection pixels among the plurality of pixels, through which control signals for switching the switch elements flow; and a plurality of signal lines, connected to the switch elements, through which electric signals flow corresponding to the charges that are generated in the pixels, in accordance with the switching state of the switch elements, wherein the radiographic imaging pixels and the radiation detection pixels are located within the common detection region.