Computed tomography apparatus for odontology, which includes an arm part arranged to be turnable, to which arm part at a distance from each other a radiation source and a receiver of image information have been arranged, in which apparatus said arm part is arranged to locate or to be transferred to such location with respect to the volume desired to be imaged that when the arm part is turned during the imaging, at least over a substantial angular range only a portion of the volume arranged to become imaged is within the radiation beam, and in which the control system of the apparatus comprises a control routine which then controls said radiation source to generate radiation as pulsed.