1. A diagnosis assistance information generating system comprising: an imaging unit structured to image a subject using a radiation source and a radiation detector structured to detect radiation which is irradiated from the radiation source and which is transmitted through the subject by a plurality of detection elements positioned two dimensionally to generate image data of the subject; and an image analysis unit structured to generate diagnosis assistance information regarding the subject abased on the image data acquired by the imaging unit; wherein, the imaging unit is able to successively irradiate radiation from the radiation source to acquire a plurality of frame images showing movement of the subject, the imaging unit further comprising: an anti-scattered radiation grid structured to remove scattered radiation from the radiation source; and an imaging control unit structured to control whether imaging is performed using the anti-scattered radiation grid; wherein, the imaging control unit is structured to control imaging to be performed without the anti-scattered radiation grid when diagnosis assistance information regarding the movement of the subject is generated by the image analysis unit.