Kabushiki Kaisha Toshiba

Mitsuru Yahata

Yasuo Saito

Masahiko Yamazaki

Shigeru Tanaka

Kyojiro Nambu

Tadaharu Kobayashi

Hidehiro Fujita

Hidetoshi Kudo

Takayuki Matsubayashi

Yutaka Shibata

Kozi Natori

Kouji Honjo

In an X-ray computerized tomography apparatus, a water phantom is interposed between an X-ray tube unit and an X-ray detector in place of a subject under examination and a plurality of pieces of data detected by a plurality of X-ray detector elements are previously measured as a pieces of compensation data while shifting the X-focal point to different positions. Compensation data corresponding to the actual position of the X-ray focal point, which shifts according to the thermal state of the X-ray tube unit, is selected to correct detect data obtained for a subject under examination, permitting optimum compensation of variations in sensitivity among the X-ray detector elements for any position of the X-ray focal point, thereby preventing a ring-like artifact from being produced on a tomography image.

X-ray computerized tomography apparatus

An X-ray computerized tomographic (CT) apparatus capable of facilitating alignment of focal spot position at the time of replacing an X-ray tube anew and capable of easily correcting the focal spot position even when the focal spot position of the X-ray tube is deviated. Thereby, the focal spot position of the X-ray tube remains fixed in a predetermined position. The X-ray computerized tomographic (CT) apparatus includes an X-ray tube which is freely movable in at least one of a horizontal direction and a vertical direction; a detection unit for detecting a dislocated degree of the focal spot position of the X-ray tube; and a controlling unit for automatically controlling the focal spot position of the X-ray tube based on data obtained from the detection unit so that the focal spot position of the X-ray tube remains fixed in a predetermined position. In a case where the CT apparatus is used for a helical scanning operation, the detection unit may further include a detection timing controller for controlling an instance of detection and alignment of the focal spot position by utilizing only an output of the X-ray amount detected at a predetermined position of a gantry.

X-ray CT apparatus having focal spot position detection means for the

In a CT (computerized tomographic) scanning apparatus, a biological body under medical examination is scanned to acquire image data on the scanned body, whereby a computerized tomographic image of the scanned body is reconstructed by processing the acquired image data. The CT scanning apparatus comprises: an AC/DC converting unit for converting AC (alternating current) power supplied from a commercial power source into first DC (direct current) power; a peak power consumption unit for consuming peak power during a scanning operation; and a secondary battery unit rechargeable by the first DC power supplied from the AC/DC converting unit and capable of supplying second DC power to the peak power consumption unit during at least the scanning operation.

Computerized tomographic scanning apparatus driven by rechargeable

In a power source device for X-ray system, circuit units are mounted on chassises, respectively and chassises are fixed in a casing and are electrically insulated from the casing by insulative members. The circuit units are electrically connected through a cable to a ground terminal of the casing which is connected to the ground. The chassises are also connected through a cable to a ground terminal of a panel board which is connected to the ground.

Power source for X-ray system

A frame structure for a CT scanner, in which a dome for containing a scanner for an object or subject to be examined has an imaging space in its central portion, and a bed plate support mechanism carries the subject, and in which a bed plate slidably drive mechanism moves the bed plate into or out of the imaging space of the dome, and the bed plate support mechanism and the bed plate slidably drive mechanism are integrally provided to the dome.

Frame structure for CT scanner

A fourth-generation X-ray CT scanner device comprises an X-ray tube for irradiating X-rays in a sector form to an object while moving on a circular orbit around the object, an annular X-ray detector array disposed coaxially with and inside the circular orbit of the X-ray tube and arranged to surround the object, for detecting the X-rays which have been irradiated from the X-ray tube and passed through the object for each channel, and a reconstruction unit for acquiring an output of the detector array to effect the reconstruction process and create a tomographic image. The X-ray array is formed of a large number of solid-state X-ray detectors and a plurality of the detectors constitute a detector module, and the array includes a large number of modules. In a displayed tomographic image, in a case where linear artifacts radiated from one point in various directions are detected, a detector module lying on an intersection (radiation point) of the artifact lines is determined as a defective detector module, and a reconstruction image is created without using output data of the defective detector module.

X-ray CT scanner device

An X-ray generator system has first and second switching devices such as transistors which are complementarily turned on and off to intermittently apply a DC voltage to the primary winding of a transformer for thereby inducing a high voltage across secondary windings of the transformer for enabling an X-ray tube to emit X-rays. The X-ray generator has a control mode in which the first and second switching devices are simultaneously turned on immediately before they start being complementarily turned on and off, for allowing the high voltage to have a sharply rising positive-going edge.

X-ray generator system

A high DC voltage generator for an X-ray tube includes a low voltage rectifier for rectifying a low AC input voltage to produce a low DC voltage, a DC-to-DC converter for converting the low DC voltage into a high DC voltage for the X-ray tube, and a controller for controlling transition characteristics of turning-on and off the X-ray tube. The controller shortens a rising time period of the high DC voltage until a rating anode voltage is applied to the X-ray tube after turn-on operation.

High DC voltage generator including transition characteristics

The anode and cathode of an X-ray tube are connected to a high-voltage power source respectively, through corresponding tetrode tubes, and the center metal electrode of the X-ray tube is grounded. The tetrode tubes are simultaneously turned on and off upon receipt of a control signal. An abnormal current, which flows through the center metal electrode due to a short-circuiting fault of the tetrode tube connected to the cathode of the X-ray tube, is detected during an OFF period of the tetrode tubes. Upon detection of the abnormal current, the tetrode tube connected to the anode of the X-ray tube is forcedly turned on, thus preventing the fusion of the center metal electrode in the X-ray tube.

Growing community of inventors

Ootawara, Japan

Mitsuru Yahata