[Objective]To reduce the radiation dosage that a subject is exposed to, while improving the image quality of subtraction images, in a radiation image processing apparatus, a radiation image processing method, and a radiation image processing program for generating subtraction images.[Constitution]A first imaging unit 31 obtains a first radiation image, which is imaged under first imaging conditions. A second imaging unit 32 obtains a plurality of projection images by tomosynthesis imaging under second imaging conditions. A reconstructing unit 34 reconstructs a plurality of projection images to generate a plurality of tomographic images of cross sectional planes of a subject. An image synthesizing unit 35 generates a second radiation image employing the plurality of tomographic images. A subtraction processing unit 36 administers a subtraction process on the first and second radiation images, to generate a subtraction image.
