摘要:
An X-ray CT apparatus includes an X-ray source for generating X-rays, a detector having detector elements laid out in a plurality of rows in a body axial direction of an object on a couch for detecting X-rays transmitted through the object, and a helical data collector that collects helical data while at least one of a gantry and the couch is moved by a moving device along a body axial direction of the object on the couch in a state that at least one of the gantry and the couch is tilted. A data processor is further provided that reconstructs an image by interpolating the helical data collected and converting it into parallel beam data that is tilt corrected.
摘要:
A multi-slice X-ray CT scanner is provided to realize high resolution and a wide scanned region in a slice-thickness direction for an object. In the X-ray CT scanner, an X-ray beam for slice imaging is radiated toward an object and scanned in a predetermined slice-thickness direction, a direction orthogonal to the slice-thickness direction being defined as a channel direction. The scanner comprises a two-dimensional X-ray detector, a data acquisition system, and an electrically combining unit. The detector has a plurality of X-ray detecting elements arranged in a two-dimensional array of both rows in the slice-thickness direction and columns in the channel direction, the detecting elements of each row being arranged in unequal pitches. The data acquisition system has a plurality of data acquiring elements arranged in a two-dimensional array of rows and columns, acquiring signals detected by the two-dimensional X-ray detector, and producing digital data proportional to the detected signals. The electrically combining unit electrically combines more than two columns of all the columns in the array of the X-ray detecting elements into at least two columns of all the columns in the array of the data acquiring elements in accordance with a given slice imaging condition. For example, each row of the array of the data acquiring elements are less in number of elements than each row of the array of the X-ray detecting elements.
摘要:
A power steering apparatus includes a worm wheel mounted on the steering shaft, a worm shaft engaged with the worm wheel, a gear housing having a wheel accommodating portion to accommodate the worm wheel and a shaft accommodating portion to accommodate the worm shaft, a bearing mounted on the worm shaft to rotatably support the worm shaft, a holder disposed in the shaft accommodating portion and having a bearing retaining portion to retain the bearing and a resilient element disposed in the shaft accommodating portion and having a resilient body portion formed with a curvature. The resilient body portion is so structured as to become deformed in such a manner as to increase or decrease in diameter when the bearing shifts in a direction that moves the worm shaft away from the worm wheel and bias the bearing in a direction that urges the worm wheel toward the worm wheel.
摘要:
A computed tomography apparatus configured to assist an operator in easily and correctly making an imaging plan thereby reducing the burden of the operator. The computed tomography apparatus selects at least one of reconstruction methods or changes a parameter by the information the operator inputs or displays its grade information, for example.
摘要:
A power steering apparatus including a joint including a first boss disposed on an axial end portion of a motor output shaft, first projections disposed on the first boss in the circumferential direction, a second boss disposed on an axial end portion of a worm shaft and opposed to the first boss, second projections disposed on the second boss in the circumferential direction and arranged between the adjacent first projections, a first elastic member made of metal and a second elastic member made of at least one of resin and rubber, the first and second elastic members being disposed between an axial end surface of the first boss and an opposed axial end surface of the second boss and cooperating with each other to generate an elastic force in such a direction as to move the worm shaft away from the motor output shaft.
摘要:
A magnetic head height changing apparatus is disclosed which is provided with a cam mechanism with a cam surface and claws, a pulley or gear device driven by a motor or fly-wheel and movable or rotatable to engage with or disengage from the cam mechanism, a first engaging device bearing a magnetic head and engageable with the cam mechanism, a second engaging device for locking the pulley or gear device when it is spaced from the cam mechanism, and an operating device for operating the second device. With the disclosed magnetic head height changing apparatus, when the second device is operated by the operating device to release the locking of the pulley or gear device and to make it contact with the cam mechanism to rotate the same by a predetermined value, the second engaging device again locks the pulley or gear device to stop the rotation of the cam mechanism to hold the magnetic head at a predetermined height.
摘要:
An X-ray computed tomography apparatus includes an X-ray tube, a high voltage generator which generates a high voltage to be applied to the X-ray tube, an X-ray detector having a plurality of X-ray detection element lines, a scanogram generating unit which generates a scanogram on the basis of an output from the X-ray detector, a reconstructing unit which reconstructs an image on the basis of an output from the X-ray detector, a tube current determining unit which determines a tube current value on the basis of the pixel values of a plurality of pixels included in a two-dimensional partial region of the scanogram, and a control unit which controls the high voltage generator on the basis of the determined tube current value.
摘要:
Upon successively acquiring a plurality of tomographic images of an identical patient, and displaying them time-serially, the display mode of images is changed. More specifically, the display order of images is switched in correspondence with the standing position of the observer. The standing position of the observer can be automatically detected. The aperture width of a precollimator is controlled in accordance with the setups of images of interest/non-interest, and data from predetermined detection element arrays are bundled in accordance with the setups. At least one of a plurality of reconstructed tomographic images and a specific image undergo a differential process to generate and display a differential image. The pixel values of at least one of a plurality of reconstructed tomographic images are compared with a predetermined threshold value to generate and display an image consisting of only pixels that have exceeded the threshold value.
摘要:
A rotation frame supports an X-ray tube and an X-ray detector to be rotatable about a rotation axis. A top plate support mechanism supports the top plate on which a sample is placed to be movable along the rotation axis. A scan controller drives the top plate support mechanism and the rotation frame so as to scan a plurality of scan areas either partially overlapping or being adjacent along the rotation axis with the X-rays. A reconstruction processor generates a plurality of volume data sets corresponding to the plurality of scan areas on the basis of the output from the X-ray detector. A boundary corrector corrects CT values of the plurality of volume data sets on the basis of CT value differences between the overlapping or adjacent portions of the plurality of volume data sets.
摘要:
According to one embodiment, an X-ray computed tomography apparatus includes an X-ray tube, X-ray detector, acquisition unit, rotating mechanism, input unit, and control unit. The input unit repeatedly inputs trigger signals originating from a specific phase of a periodic motion of a body of a subject or a periodic motion of an organ of the subject. The trigger signals being supplied from a measuring device which measures the periodic motion. The control unit causes the X-ray tube to start generating X-rays on the basis of the input of a first trigger signal of the repeatedly input trigger signals, and causes the X-ray tube to stop generating X-rays on the basis of the input of a second trigger signal next to the first trigger signal in order to repeatedly scan the subject over substantially one period of the movement while a scan position is fixed.