摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The present invention provides a detector which suppress the crosstalk between detector cells while improving the acquisition efficiency of X-ray radiation. The detector includes a plurality of detector cells, arranged along a detection plane of X-ray, in which each detector cell has a scintillator unit made of a scintillator, and a photodiode for transduce the light incoming from the scintillator unit into electric signals. The scintillator units are partitioned each from another by the border, which has a groove extending in the channel and row directions. A scintillator is provided in some part of the border in the incident X-ray direction.
摘要:
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.
摘要:
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.
摘要:
A CT image reconstruction method includes substituting other projection data, which has a predetermined positional relationship to projection data that is found defective during scanning, for the defective data, and interpolating back projection data using a value and information on a scanned position that are contained in the substitute data.
摘要:
The present invention comprises: an X-ray generator that generates two cone beam X-radiations which pass through two successive slabs; an X-ray detector that detects a two-dimensional distribution of intensities exhibited by the two cone beam X-radiations having passed through the two slabs; an acquisition unit that acquires a plurality of view of projection data representing the two slabs on the basis of detection signals sent from the X-ray detector; and a reconstruction unit that reconstructs an image according to the projection data.
摘要:
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.