Abstract: An X-ray absorptance map associated with an object to be examined is generated on the basis of scanogram data obtained from a predetermined direction of the object, and imaging conditions are determined on the basis of the absorptance map. Before tomography, an index representing a radiation dose in the execution of scan in accordance with the imaging conditions is calculated and displayed, together with the imaging conditions. Every time the imaging conditions are changed, an index representing a radiation dose is calculated and displayed. Tomography is executed in accordance with the finally determined imaging conditions. This makes it possible to reduce the radiation dose to the object and obtain a tomographic image with high quality.

Abstract: An X-ray absorptance map associated with an object to be examined is generated on the basis of scanogram data obtained from a predetermined direction of the object, and imaging conditions are determined on the basis of the absorptance map. Before tomography, an index representing a radiation dose in the execution of scan in accordance with the imaging conditions is calculated and displayed, together with the imaging conditions. Every time the imaging conditions are changed, an index representing a radiation dose is calculated and displayed. Tomography is executed in accordance with the finally determined imaging conditions. This makes it possible to reduce the radiation dose to the object and obtain a tomographic image with high quality.

Abstract: The rotation component supported rotatably with respect to the gantry includes a cylindrically-shaped rotation base, and a disk-like frame provided in parallel to the bottom surface of the cylinder of the rotation base so as to partition it at substantially a middle way through. The frame has a plurality of unit opening sections for arranging the unit, and further an opening section. The structural elements provided in the rotation component, namely, the X-ray tube unit, signal amplification unit, cooling unit, power units and power control unit are fit into the predetermined unit opening section of the frame, and are fixed onto the inner wall surface of the cylindrical rotation base.

Abstract: An X-ray CT apparatus includes a frame 1 and a radiographic unit accommodated in the frame 1. The upper portion of the frame 1 is shaped to be generally semicircular. In this X-ray CT apparatus, almost electric components 9 are positioned in the lower part of the frame 1 collectively. Consequently, such a positioning of the electric components makes it easy to realize a shielding structure for the components against the electromagnetic noises. It is possible to arrange a power line 15 and a signal line 16 in a perfectly separated manner and reduce the wiring area and length of the lines 15, 16.

Abstract: A radiation computed tomography apparatus of this invention includes a couch, a top board which carries the patient and is slidably arranged on the couch, a gantry which has an opening and acquires projection data of a patient by guiding the patient carried on the top board into the opening, reconstruction section for reconstructing the tomographic image of the patient by reconstructing the projection data acquired by the gantry, and adjusting section, arranged on or near the gantry, for adjusting the photographing condition of the patient for obtaining a predetermined tomographic image of the patient.

Abstract: An X-ray CT system includes a fixed frame portion and a rotating frame portion. Being provided with X-ray tubes, the rotating frame portion is arranged so as to rotate with respect to the fixed frame portion. Vane members for feeding air are secured on the rotating frame portion. In operation, with the rotation of the vane members together with the rotating frame portion, cool air is introduced into the rotating frame portion. Consequently, heated instruments, such as the X-ray tubes, in the rotating frame can be cooled down effectively.

Abstract: A radiation computed tomography apparatus of this invention includes a couch, a top board which carries the patient and is slidably arranged on the couch, a gantry which has an opening and acquires projection data of a patient by guiding the patient carried on the top board into the opening, reconstruction section for reconstructing the tomographic image of the patient by reconstructing the projection data acquired by the gantry, and adjusting section, arranged on or near the gantry, for adjusting the photographing condition of the patient for obtaining a predetermined tomographic image of the patient.

Abstract: A radiation computed tomography apparatus of this invention includes a couch, a top board which carries the patient and is slidably arranged on the couch, a gantry which has an opening and acquires projection data of a patient by guiding the patient carried on the top board into the opening, reconstruction section for reconstructing the tomographic image of the patient by reconstructing the projection data acquired by the gantry, and adjusting section, arranged on or near the gantry, for adjusting the photographing condition of the patient for obtaining a predetermined tomographic image of the patient.

Abstract: In an X-ray computed tomography apparatus for producing a sectional image of an object, an X-ray computed tomography gantry comprises an X-ray tube unit, an X-ray tube cooling unit, an X-ray detection unit, a signal amplifier unit, a mechanical control unit, and a power source unit. These units are fixed on the rotating base. These units are integrally fixed at portions thereof opposite to portions thereof fixed on the rotating base by a band.