JP2006218140A - Radiographic x-ray apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radiographic X-ray apparatus having a top plate part mountable of a subject, capturing a superior image, or executing efficient imaging. <P>SOLUTION: This radiographic X-ray apparatus is characterized in having an imaging bed having the top plate mountable of the subject, a radiographic image detector detecting the distribution of X-ray intensities transmitting through the subject, and a rotating means having a rotating shaft different from the center of the radiographic detector in a vertical plane to an X-ray input shaft and rotating the radiographic image detector. The radiographic detector is characterized in compensating the whole imaging ranges in the top plate narrow side direction of the imaging bed by the rotating means. The rotating means is characterized in having a control means capable of revolving 360° and stopping for every 90°. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray imaging apparatus using a planar image detector that detects an intensity distribution of radiation such as X-rays transmitted through a subject.

  Conventionally, the most common imaging method for X-ray imaging is a film / screen method, which is a method of imaging by combining a photosensitive film and a phosphor having sensitivity to X-rays. As a second imaging method, a method called a computed radiography (CR) method has been put into practical use. In this method, an X-ray transmission image is temporarily stored as a latent image in a phosphor, and the latent image is read by irradiating excitation light later.

  Further, along with recent progress in semiconductor process technology, an apparatus for taking X-ray images in the same manner using a semiconductor sensor has been developed as a third imaging method. This type of system has the advantage that an image of an extremely wide X-ray exposure area can be recorded as compared with a conventional X-ray photography system using a silver salt photograph.

  That is, X-rays in a wide dynamic range are read by photoelectric conversion means and converted into electrical signals, and then X-ray images are visualized on recording materials such as photographic photosensitive materials and display devices such as CRTs using the electrical signals. As a result, it is possible to obtain an X-ray image that is hardly affected by fluctuations in the amount of X-ray exposure.

  FIG. 4 is a schematic diagram of an X-ray imaging system using the above-described semiconductor sensor. The X-ray imaging apparatus 101 includes an X-ray having a detection surface in which a plurality of photoelectric conversion elements are two-dimensionally arranged. A detection sensor 102 is built in, the X-rays emitted from the X-ray generator T are irradiated onto the subject S, and the X-rays transmitted through the subject S are detected by the X-ray detection sensor 102. The image signal output from the X-ray detection sensor 102 is subjected to digital image processing in the image processing unit 103 and displayed as an X-ray image of the subject S on the monitor 104. Such an X-ray detection sensor is called a flat detector, a flat panel, or the like because of its shape.

  In order to enable imaging of a wide range of parts more quickly with an apparatus using the X-ray detection sensor, a portable imaging apparatus called an electronic cassette having excellent operability has been proposed (for example, (See Patent Documents 1 and 2).

  There is also an imaging method using a scattered X-ray removal grid for the purpose of improving the contrast of the X-ray image. This is for removing scattered X-rays generated by internal transmission of the subject by X-ray irradiation, and this scattered X-ray removing grid is arranged between the X-ray tube and the X-ray image detector. And take a picture.

  This scattered X-ray removal grid is composed of a plurality of foils made of lead or the like having a high X-ray absorption rate as an X-ray absorption member, aluminum, paper, wood, synthetic resin, carbon fiber reinforced resin having a low X-ray absorption rate, etc. The intermediate material made of is alternately laminated and covered with a cover member made of aluminum or the like. In this case, since X-rays are incident from a direction along the surface of the foil, scattered X-rays enter the foil at a certain angle and are absorbed by the foil. Since the X-ray primary light transmitted through the subject is incident on the foil in parallel, it passes through the intermediate material portion and passes through the grid. Therefore, the scattered X-rays scattered in the subject can be absorbed by the foil, and a reduction in resolution due to the scattered X-rays can be prevented.

  FIG. 5 is a side view of a schematic configuration of an imaging apparatus using a conventional X-ray image detector in a Bucky imaging table that can be used when performing simple imaging of the extremities, head, abdomen, and the like of the subject S. FIG. Is an example of a perspective view.

  On the base 8 provided with the lifting mechanism, the top plate 3 for lying down the subject S is supported by the slide mechanism portions 4 and 5 that move in the front-rear and left-right directions on the paper surface, and is attached so as to be movable back and forth and right and left. . An imaging unit 1 is configured between the top 3 and the base 8, and the imaging unit 1 includes a rotary table 6 having an X-ray incident axis as a rotation axis and a slide mechanism 7 that moves in the left-right direction on the paper surface. Via, it is incorporated so that it can move left and right and rotate freely.

  The imaging unit 1 incorporates an X-ray image detector and a scattered X-ray removal grid (not shown). The upper part of the imaging unit 1 is covered with a cover made of a material having a high X-ray transmittance. Built-in detachable.

  X-rays are emitted from a tube T located on the top of the subject S, and the X-ray transmitted through the subject S lying on the top 3 is received by the imaging unit 1.

JP-A-55-012429 JP-A-56-011395

  Generally, as the distance between the subject and the X-ray image receiving unit (imaging unit 1) increases, the acquired X-ray image is blurred and the resolving power (MTF) decreases. For this reason, it is not preferable to increase the interval.

  In addition, when it is desired to image a region wider than the effective imaging range of the X-ray image detector, the photographer usually moves the subject S by moving the top 3 and divides the image in two times. The acquired images are stitched by image processing, but the positional relationship between the images is unclear or the subject's position moves slightly. The load is also great.

  In addition, in the case of a subject who is incapable of moving, the positioning by moving the top plate 3 gives a burden, or when the subject slides in the front-rear direction of the paper, that is, moves in the left-right direction of the subject, There is a risk of falling from the top 3.

  An object of the present invention is to provide an X-ray imaging apparatus that includes a top plate part on which a subject can be placed and can obtain a good image or perform efficient imaging.

  In order to achieve the above object, the present invention according to claim 1 includes an imaging bed having a top plate on which a subject can be mounted, an X-ray image detector for detecting an intensity distribution of X-rays transmitted through the subject, A rotation means for rotating the X-ray image detector has a rotation axis different from the center of the X-ray image detector in a vertical plane with respect to the X-ray input axis.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing a test subject's load and risk, the fall of a resolution and an image processing work load can be reduced, and a favorable image can be obtained or efficient imaging | photography can be performed.

  The present invention will be described in detail with reference to FIGS. In the following embodiments, a medical imaging apparatus (X-ray imaging apparatus) for imaging a subject using X-rays will be described as an example of the X-ray imaging apparatus of the present invention. It is also possible to apply the invention to an X-ray image photographing apparatus for photographing another subject or an imaging apparatus using other X-rays.

  FIG. 1 is a perspective view of an X-ray imaging apparatus according to an embodiment. A schematic configuration of the X-ray imaging apparatus will be described with reference to FIG.

  A top plate 12 for leaning the subject S is supported and attached to a base 15 provided with an elevating mechanism by a slide mechanism unit 13 that freely moves only in the left-right direction on the paper surface. An imaging unit 11 is configured between the top 12 and the base 15, and the imaging unit 11 is rotatably incorporated via a rotary table 14 having an X-ray incident axis as a rotation axis.

  The imaging unit 11 incorporates an X-ray image detector and a scattered X-ray removal grid (not shown). The upper part of the imaging unit 11 is covered with a cover made of a material having a high X-ray transmittance, and is detached from the imaging table. Embedded as possible.

  FIG. 2 is a schematic view of the imaging range 11r of the X-ray image detector built in the imaging unit 11 and the imaging range 12r of the top 12 viewed from the X-ray incident direction. As shown in the figure, the imaging range 11r of the X-ray detector is rotated by the rotating means 14 with an eccentric position different from the center as a rotation center. When the rotation angles are 90 degrees and 270 degrees, the imaging range 11r of the X-ray image detector can compensate for the entire range of the top and bottom imaging range 12r in the vertical direction of the paper.

  Further, before and after the rotation, the position where the overlap region is provided in the imaging range of the X-ray image detector, the axis y is the symmetry axis when the image range 11r of the X-ray image detector is rotated by 0 degrees and 180 degrees, respectively. When rotated by 90 degrees and 270 degrees, the axis x has a center of rotation that is the axis of symmetry.

  According to the present embodiment, it is possible to reduce the distance between the upper surface of the photographing unit 11 and the top plate 12 by omitting the left and right sliding means of the photographing unit and the front and rear sliding means of the top plate in the conventional example.

  The combination of the left and right sliding means of the top plate 12 and the eccentric rotation means of the photographing unit 11 enables photographing in a range of 90% or more of the top plate photographing range 12r, and almost 100% of the subjects dressed on the top plate 12 The range can be photographed. As described above, by providing an overlapping area in the X-ray image detector imaging range 11r before and after the rotation, the angle data stored in the rotation angle storage means (not shown) can be used when performing image processing such as stitching in wide-range imaging. Combine and use as a collation area for image composition.

  Further, it is possible to perform rotation control from the operation room and automatically correct and display the orientation of the acquired image at the time of rotation, thereby reducing the burden on the photographer.

  FIG. 3 shows a modification of the rotation center. When the image range 11r of the X-ray image detector is rotated by 0 degrees and 180 degrees, the axis d2 is a symmetric axis, and when the image range 11r is rotated by 90 degrees and 270 degrees, the axis d1 is a symmetric axis. FIG. 6 is a schematic diagram of an imaging range 11r of the X-ray image detector built in the imaging unit 11 and an imaging possible range 12r of the top plate 12 as viewed from the X-ray incident direction when the rotation center is formed.

  Needless to say, the X-ray imaging apparatus of the above-described embodiment is not limited to these embodiments and can be variously modified without departing from the scope of the claims.

1 is a perspective view illustrating a schematic configuration of an X-ray imaging apparatus according to the present invention. It is a schematic diagram explaining the imaging | photography range of the X-ray image imaging device which concerns on this invention. It is a schematic diagram explaining the imaging | photography range of the modification of the X-ray image imaging device which concerns on this invention. It is explanatory drawing of the conventional X-ray imaging system. It is a side view explaining the schematic structure of the X-ray imaging apparatus using the conventional imaging stand. It is a perspective view explaining schematic structure of the X-ray imaging device using the conventional imaging stand.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Imaging | photography part 11r Effective imaging | photography range of X-ray image detector incorporated in imaging | photography part 12 Top plate 12r The imaging | photography possible range of a top plate 13 Top-plate right-and-left slide mechanism 14 Turntable 15 Base

Claims (6)

  An imaging bed having a top plate on which a subject can be mounted, an X-ray image detector for detecting an intensity distribution of X-rays transmitted through the subject, and a center of the X-ray image detector in a vertical plane with respect to an X-ray input axis An X-ray imaging apparatus, comprising: a rotating unit having a rotation axis different from that of the X-ray image detector.   2. The X-ray image photographing apparatus according to claim 1, wherein the X-ray image detector supplements all the photographing possible range in the short side direction of the top of the photographing bed by the rotating means.   The X-ray imaging apparatus according to claim 1, wherein the rotation unit includes a control unit that can rotate 360 degrees and can stop every 90 degrees.   The X-ray imaging apparatus according to claim 1, wherein the rotation unit includes an operation unit for performing a rotation operation even from a panel provided at an isolation position.   4. The X-ray imaging apparatus according to claim 1, further comprising storage means for storing angle information of the X-ray image detector generated when the rotating means is operated.   6. The X-ray imaging apparatus according to claim 5, further comprising image processing means for displaying and synthesizing images in an appropriate direction based on the angular position information and acquired image data stored in the storage means.

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