1. A trabecular bone analyzer comprising: a radiation source configured to emit radiation; a detector to detect radiation that has passed through a subject; a radiation source moving unit configured to move the radiation source in one direction; a radiation source movement control unit configured to control the radiation source moving unit; an image generating unit configured to generate an image based on an output from the detector; an image reconstructing unit configured to generate a tomographic image based on images continuously taken by moving the radiation source with respect to the subject; and a trabecular bone analyzing unit configured to calculate, based on the tomographic image, data for quantitatively determining a state of trabecular bone.