Computed tomography apparatus

A computed tomography apparatus comprising:

• a plurality of imaging units, each of which is composed of:
• a radiation source that emits radiation having a quadrangular pyramid shape to a subject positioned in either a standing posture or a sitting posture, and
• a radiation detector in which a plurality of pixels detecting the radiation transmitted through the subject are two-dimensionally arranged and which outputs a projection image of the subject;
• a rotation mechanism that rotates each radiation source and each radiation detector around a body axis of the subject;
• an elevating mechanism that raises and lowers each radiation source and each radiation detector along a rotation axis direction;
• and
• a processor that controls operations of the radiation source, the radiation detector, the rotation mechanism, and the elevating mechanism,
• wherein the processor performs conventional scanning, which directs the rotation mechanism to rotate the radiation source and the radiation detector without changing a positional relationship between the subject, and the radiation source and the radiation detector in the rotation axis direction, directs the radiation source to emit the radiation whenever the radiation source and the radiation detector are rotated by a preset angle, and directs the radiation detector to output the projection image, at a plurality of height positions along the rotation axis direction and generates a tomographic image on the basis of the projection images obtained at the plurality of height positions, and
• wherein, in a case in which an imaging range that exceeds a width of a detection surface for the radiation in the radiation detector is to be imaged by rotating the plurality of imaging units in parallel, the processor sets an interval between the plurality of imaging units in the rotation axis direction such that a second overlapping imaging range occurs between projection images obtained by imaging units adjacent to each other, generates a plurality of tomographic images for each of the plurality of imaging units on the basis of projection images obtained from each of the plurality of imaging units, and registers the plurality of tomographic images on the basis of the second overlapping imaging range to combine the plurality of tomographic images.