JP2006204329A - X-ray tomographic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an operator to easily make an accurate scanning plan using visible light images even if the operator does not have sufficient experience or intuition. <P>SOLUTION: An X-ray photographing means irradiates a subject with X rays from an X-ray source and photographs the subject with a detector disposed to face the X-ray source. A scanner rotating means rotates the X-ray source and the detector around the subject. A subject moving means moves the subject. A visible light photographing means is mounted on the scanner rotating means to photograph the visible light reflected from the subject. An image processor generates an X-ray three-dimensional reconstructed image by a reconstruction operation means from the projected image photographed by the X-ray photographing means and reconstructs a visible light three-dimensional image from the result of the photography by the visible light photographing means. A display means superimposes the X-ray three-dimensional reconstructed image and the visible light three-dimensional image produced by the image processor and displays the superimposed image. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray tomography apparatus that irradiates X-rays in a conical shape, and realizes positioning of an imaging region by a new technique of using a visible light imaging apparatus and its imaging results.

  FIG. 1 is a diagram showing an example of a conventional X-ray tomography apparatus. As shown in FIG. 1, a conventional X-ray tomography apparatus includes a measurement device that captures a two-dimensional X-ray image (projection image), an image processing device that stores the projection image and reconstructs the tomogram, An image display device for display and an external input device for inputting information such as characters are configured.

  As shown in the figure, the scanner 1 is arranged such that an X-ray tube 11 and a two-dimensional detector 12 face each other with the subject 7 interposed therebetween. The X-ray tube 11 irradiates the subject 7 with conical X-rays from the X-ray focal point. The two-dimensional detector 12 detects the intensity of the X-ray transmitted through the subject 7. The X-ray intensity detected by the two-dimensional detector 12 is signal-processed as projection image data. The X-ray tube 11 and the two-dimensional detector 12 are configured to rotate around the body axis of the subject 7 as the center of rotation. Each time the X-ray tube 11 and the two-dimensional detector 12 rotate by a minute angle, the X-ray tube 11 irradiates the cone-shaped X-ray and the intensity of the X-ray transmitted through the subject 7 is measured by the two-dimensional detector 12. Detected. This operation is repeated for the entire circumference, and as a result, hundreds to several hundreds of transmitted X-ray intensity data are collected as projection image data.

  The transmitted X-ray intensity data measured by the two-dimensional detector 12 is converted into a digital signal and then sent to the image processing unit 4. Transmitted X-ray intensity data (hereinafter referred to as a projection image) sent from the measurement unit is temporarily stored in the memory 42 via the interface (I / F) 41 and then stored in the hard disk 43. In this way, the projection image is saved.

  When displaying the projection image, the projection image stored in the hard disk 43 is once read into the memory 42 and the read data is displayed on the display device 5. When correcting the projection image, the projection image stored in the hard disk 43 is once read into the memory 42, and the CPU 44 corrects the disturbance of the projection image caused by the sensitivity unevenness of the detector. The corrected projection image is reconstructed.

In the filtering process, the entire projection image is corrected using a correction filter such as a well-known Shepp-Logan filter in the CPU 44.
In the three-dimensional reconstruction calculation, the three-dimensional X-ray absorption coefficient distribution in the region where the subject 7 is displayed is reconstructed in the CPU 44 from the projection image obtained by performing the above-described processing, and 3 3 Create a dimensional reconstruction image. As a reconstruction calculation method, a cone beam reconstruction calculation based on the well-known Feldkamp method is known.

  The three-dimensional reconstructed image can be stored in the hard disk 43 or the like. When displaying the three-dimensional reconstructed image, the three-dimensional reconstructed image stored in the hard disk 43 or the like is read to the memory 42 and the data read to the memory 42 is displayed on the display device 5. In the reprojection calculation, the three-dimensional reconstructed image stored in the hard disk 43 shown in FIG. 1 is read into the memory 42, and the CPU 44 performs the reprojection calculation disclosed in, for example, Patent Document 1, and the three-dimensional reprojection image. Create The created three-dimensional reprojection image is stored in the hard disk 44. In order to display the three-dimensional reprojection image stored in the hard disk 44, it is read from the hard disk 44 to the memory 42 and displayed on the display device 5.

  In the prior art, so-called scan planning is generally performed in which an imaging range is planned using a projection image or the like before reconstruction. The scan plan includes, for example, a scanogram in which an X-ray tube and a detector are fixed at an arbitrary position without rotating, and X-rays are irradiated toward a subject while moving a bed to obtain a projection image. Since this method can obtain an X-ray projection image, it has the merit that a scan plan can be performed even on a portion of the body of the subject that is difficult to confirm from outside the body, but is accompanied by exposure by X-rays. There was a risk.

  Further, in the conventional X-ray scan plan, imaging is performed in the following procedure. In other words, the examinee is first positioned on a chair or bed, and the examiner often performs remote positioning based on experience and intuition and performs fluoroscopy. The examiner repeatedly performs fine adjustment while confirming the fluoroscopic image. In many cases, the fine adjustment is performed by seeing through the arm rotation angles of 0 °, 90 °, and 0 ° three times to adjust whether a desired area is included in the shooting range in the vertical and horizontal positions. In order to accurately obtain the position by fine adjustment, the examiner needs experience and intuition, and the subject is forced to be exposed.

Patent Document 2 describes that a CT scanner controls the movement of a couch using a two-dimensional imaging result of a video camera. However, this is only used to control the bed feeding of the CT scanner.
Japanese Patent Laid-Open No. 9-253079 JP-A-8-126638

As described above, conventionally, an X-ray fluoroscopic image is used for a scan plan, and a visible light image captured by a video camera is only used for another control.
The present invention has been made in view of the above points, and provides an X-ray tomography apparatus capable of easily realizing an accurate scan plan using a visible light image even if experience and intuition are not abundant. There is to do.

  The first feature of the present invention is that X-ray imaging means for irradiating an X-ray from an X-ray source and imaging a subject by a detector arranged opposite to the X-ray source, the X-ray source and the detection Scanner rotating means for rotating the instrument around the subject, subject moving means for moving the subject, visible light imaging means for imaging the subject placed on the scanner rotating means, and the X-ray imaging An image processing apparatus for generating an X-ray three-dimensional reconstructed image from a projection image photographed by the means by a reconstruction computing means and reconstructing a visible light three-dimensional image from a photographing result of the visible light photographing means, and the image processing And a display means for displaying the X-ray three-dimensional reconstructed image and the visible light three-dimensional image generated by the apparatus in a superimposed manner.

  According to the present invention, it is possible to easily realize an accurate scan plan using a visible light image even if experience and intuition are not abundant.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 shows an example of the hardware configuration of the X-ray tomography apparatus of the present invention. In this example, a sitting X-ray diagnostic apparatus for imaging the head and neck is shown, but the X-ray tomography apparatus may be a C-arm type apparatus, a CT apparatus, a subject rotation type apparatus, or the like.

  As shown in the figure, the scanner 1 is arranged such that an X-ray tube 11 and a two-dimensional detector 12 face each other with the subject 7 interposed therebetween. The X-ray tube 11 emits X-rays. The detector 12 detects X-rays emitted from the X-ray tube 11. The scanner supporter 17 is a column that supports the scanner 1. The scanner rotation shaft 18 is the rotation center of the scanner 1 and is provided so as to substantially coincide with the body axis of the subject 7. The scanner driving means 19 is for rotating the scanner 1 around the scanner rotation shaft 18. The collimator 2 limits the X-ray range irradiated from the X-ray tube 11. The collimator driving unit 29 drives the collimator 2 to control the limited range of X-rays. The chair 3 is for the subject 7 to sit and fix the position. It is supported by the chair support 31 and the position of the chair 3 is driven by the chair driving means 39.

  The image processing unit 4 generates an image by variously processing the X-ray intensity signal detected by the detector 12, and includes an interface (I / F) 41, a memory 42, a hard disk 43, a CPU 44, and the like. The The interface (I / F) 41 performs input / output of an X-ray projection image and a visible light image and communication between the scanner driving unit 19, the chair driving unit 39, and the collimator driving unit 29. The memory 42 stores image data or temporarily stores data generated by various processes. The hard disk 43 stores image data necessary for arithmetic processing. The CPU 44 performs arithmetic processing. The display device 5 displays an X-ray projection image, a visible light image, and the like. The external input device 6 is a keyboard or the like operated by an operator. The camera 8 captures visible light and does not cause the subject 7 to be exposed. The illumination 9 irradiates the subject 7 with light.

  FIG. 3 is a diagram illustrating an arrangement of the camera 8 and the illumination 9 with respect to the scanner 1 in the measurement apparatus illustrated in FIG. The camera 8 is disposed at a position shifted from the focal point of the X-ray tube 11 by an angle t about a scanner rotation axis 18 that substantially coincides with the body axis of the subject 7. As shown in FIG. 3B, when the scanner 1 is rotated clockwise in FIG. 3 by an angle t, a visible light image from the same rotation angle as the image viewed from the focal position of the X-ray tube 11 is obtained by the camera 8. Will be obtained. Further, by illuminating the illumination 9 from the camera 8 side, it is possible to always obtain an image with less shadow on the subject 7. In the figure, the illumination 9 is provided separately from the camera 8, but it is desirable to use a ring-shaped illumination that is mounted around the lens of the camera 8 in order to reduce shadows due to illumination. In order to further reduce shadows, a plurality of light sources may be used to illuminate the subject 7 from various directions. Further, if a ring light and a plurality of light sources are used, it is possible to further reduce shadows. The camera 8 performs shooting in synchronization with the rotation angle of the scanner 1. As a result, the camera 8 can perform rotation imaging about 360 ° around the subject 7 and obtain a plurality of angle-synchronized rotation captured images.

  FIG. 4 is a diagram illustrating a process of generating a three-dimensional reconstructed image based on the rotationally captured image obtained by the camera 8. FIG. 5 is a flowchart showing a flow of processing for generating a three-dimensional reconstructed image based on the rotationally captured image obtained by the camera 8.

  First, in the first step S50, a visible light mask image rotation photographing process is performed to obtain a plurality of mask images by performing rotational photographing with the camera 8 in a state where the subject 7 is not sitting on the chair. When photographing this mask image, the chair 3 is moved to a predetermined position. A plurality of the predetermined positions can be set in accordance with, for example, the difference in the physique between the child and the adult, and the parts such as the head, tooth and jaw, and neck.

  Further, the photographing range by the camera 8 is wider than that of the X-ray projection image, and a wide visual field range including the X-ray projection image is photographed. The field of view range, that is, the shooting range by the camera 8, can be enlarged or reduced depending on the situation.

  Further, the above mask image need not be taken every time before the subject 7 is photographed, and a rotated image photographed at a predetermined position is stored in the hard disk 43 in the image processing apparatus, and the chair 3 What is necessary according to a predetermined position or the like may be developed in the memory 42 and used for image processing.

In step S51, the subject 7 is seated on the chair, and subject setting processing for moving the position of the chair 3 by the chair driving means 39 is performed according to the physique and the part of the subject 7.
In step S52, imaging is performed while rotating the scanner support 14 with the camera 8 while the subject 7 is sitting on the chair 3, and a visible light live image rotation imaging process for obtaining a plurality of live images is performed. .

  In step S53, subject extraction image generation processing is performed to extract subject 7 from the live image acquired in step S52. This processing is performed by first creating an image by subtracting a plurality of mask images and a live image for each angle.

  The mask image used here is taken at the same position as the position of the chair 3 in the live image. If the image obtained by the camera 8 is in color, it is mapped in gray scale and converted to monochrome display before performing the difference. In addition, since an image matrix of 128 × 128 pixels or less is sufficient, when the camera can obtain a large image matrix, the pixels are regularly thinned and used.

  Since the backgrounds of the chair 3 and the detector 12 other than the subject 7 are the same between the mask image and the live image, the pixel values of the background other than the subject are almost zero in these difference images. For this reason, for example, an area having a pixel value other than ± 20 is extracted as the subject extraction area. A subject extraction image is generated in which the pixel value of the subject extraction region is 1 and the background pixel value other than the subject extraction region is 0.

  Here, it is preferable that the chair 3 is as small as possible in order to sufficiently obtain an image from the rear of the imaging region of the subject 7. For example, when photographing a tooth and jaw part, it is desirable that the headrest and the portion supporting it are made as narrow as possible so that a subject extraction image can be sufficiently generated. More preferably, a more complete subject extraction image can be obtained if the headrest and the portion supporting it are made of a transparent material.

  In step S54, a cone beam reconstruction calculation based on the well-known Feldkamp method is executed in the CPU 44 on the basis of a plurality of subject extracted images obtained by rotational imaging to create a visible light three-dimensional reconstruction image. The created visible light three-dimensional reconstructed image is stored in the hard disk 43 shown in FIG. In the three-dimensional reconstructed image display, the visible light three-dimensional reconstructed image stored in the hard disk 43 by storing the three-dimensional reconstructed image is read into the memory 42 shown in FIG. 1, and the data read into the memory 42 is displayed on the display device 5. To display.

  In step S55, the visible light three-dimensional reconstructed image stored in the hard disk 43 is read out to the memory 42, and the reprojection calculation is performed in the CPU 44 by, for example, the reprojection calculation means disclosed in Patent Document 1, so that the visible light is visible. A visible light three-dimensional reprojection image generation process for creating a light three-dimensional reprojection image is performed. Hereinafter, the reconstructed image basically means a tomographic image of the subject, and the reprojected image indicates a three-dimensional image constructed from the reconstructed image.

  Further, based on the live image and the subject extracted image, a subject extracted live image is generated by replacing the background of the subject of the live image with a blue screen or the like. The plurality of subject extracted live images can be texture-mapped on the subject surface of the three-dimensional reprojection image to obtain a color three-dimensional projection image of the subject.

  FIG. 6 is a diagram illustrating a process of generating an image used for positioning by superimposing the X-ray fluoroscopic image obtained by the X-ray detector 12 and the visible light three-dimensional reprojection image. FIG. 7 is a flowchart showing a flow of processing for generating an image used for positioning by superimposing the X-ray fluoroscopic image obtained by the X-ray detector 12 and the visible light three-dimensional reprojection image.

  First, in step S70, the subject 7 is seated on the chair at the same position as the visible light photographing, and the subject 7 is seated on the chair in accordance with the physique and part of the subject 7 and the chair 3 A subject setting process for moving the position by the chair driving means 39 is performed.

  In the next step S71, the scanner support unit 14 is set to perform imaging from the LAT direction, and LAT positioning image imaging processing for imaging with the X-ray tube 11 and the detector 12 is performed. Thereby, a LAT positioning image is acquired.

  In step S72, the AP support image capturing process is performed in which the scanner support unit 14 is rotated, the scanner support unit 14 is set to capture from the AP direction, and the X-ray tube 11 and the detector 12 capture images. Do. Thereby, an AP positioning image is acquired. Note that the imaging range by the detector 12 can be selected by user settings. The imaging range can be reduced by the collimator 2 according to the situation.

In step S73, the visible light three-dimensional reprojection image created in the process of FIG. 5, the LAT positioning image acquired in step S71, and the AP positioning image acquired in step S72 are superimposed. Process to generate the image.
In step S74, positioning is performed using the three-dimensional image obtained by superimposing the X-ray fluoroscopic image and the visible light three-dimensional reprojection image obtained as described above.

  FIG. 8 is a diagram illustrating an example of a visible light three-dimensional projection image acquired by the above-described processing. FIG. 9 is a diagram illustrating an example of a case where a fluoroscopic image by X-rays is displayed superimposed on the visible light three-dimensional projection image of FIG. FIG. 9 shows a case where both the LAT-direction perspective image and the AP-direction perspective image are displayed in an overlapping manner.

  The visible light three-dimensional reconstructed image in FIG. 8 is generated based on the position of the rotation center axis of the scanner on the camera image, the geometric distance between the camera and the rotation center axis, the pixel size, and the like. The geometric position of the scanner 1 and the camera 8 such as the rotation center axis, rotation surface, and rotation center of the scanner can be reproduced on the visible light three-dimensional reprojection image.

  In addition, these geometric positions are the geometry of the X-ray three-dimensional reconstructed image and the perspective three-dimensional reprojected image obtained by the X-ray obtained by the X-ray tube 11 and the detector 12 arranged on the same scanner. It can be matched with the scientific position. With respect to the installation positions of the X-ray tube 11 and the detector 12, the installation position of the camera 8 is mechanically adjusted or corrected by software, thereby rotating the rotation center axis of the scanner 1 on the visible light three-dimensional projection image. It is also possible to match the geometric positions of the surface and the center of rotation.

  The X-ray fluoroscopic image region differs depending on the shape of the detector 12. When the detector 12 is circular like an image intensifier, the fluoroscopic image region is circular. When the detector 12 is rectangular like a flat panel, the perspective image area is rectangular.

  FIG. 9 shows the subject's visible light three-dimensional reprojection image generated based on the camera image and the X-ray fluoroscopic image (LAT direction fluoroscopic image, AP direction fluoroscopic image) obtained as described above. By superimposing and displaying, it is possible to express as an image which region of the subject's body 7 that is currently sitting can be re-projected with fluoroscopy with X-rays. The operator can confirm these superimposed images using the display device of FIG.

  FIG. 10 is a diagram illustrating a relative movement relationship between the camera system coordinate system and the X-ray measurement system coordinate system. When the X-ray fluoroscopic image does not include the part to be measured by the subject 7, the external input device of FIG. 1 is operated and reflected in the chair driving means 39 to reflect the X-ray fluoroscopic image region and The subject's visible light three-dimensional reprojection image generated based on the camera image is relatively moved and adjusted. In FIG. 10, by moving the X-ray measurement system coordinate system in the front direction of the subject with respect to the camera measuring instrument coordinates, the entire tooth portion of the subject is included in the three-dimensional reprojection image region by X-rays. It shows that it was set as follows.

  FIG. 11 is a diagram showing the relationship between the visual field size of the detector or the change of the visual field size by the collimator. When changing the X-ray fluoroscopic three-dimensional reprojection image area, the external input device shown in FIG. 1 is operated to drive the imaging area range and collimator of the detector to change the X-ray fluoroscopic image area. Thus, a more appropriate X-ray fluoroscopic image region is designated. FIG. 11 shows the result of selecting a region model smaller than that in FIG. By selecting a wide area model, a wider range of three-dimensional reprojection images can be obtained. In addition, by selecting a small area model, it is possible to obtain an image of only the part of interest in detail and to suppress exposure of the subject.

  FIG. 12 is a diagram showing that only the fluoroscopic image in the LAT direction among the fluoroscopic images by X-rays is displayed superimposed on the visible light three-dimensional reprojection image of the subject. FIG. 13 is a diagram showing that only a perspective image in the AP direction among the fluoroscopic images by X-rays is displayed superimposed on the subject's visible light three-dimensional reprojection image. In this way, the fluoroscopic image can be displayed by selectively using only an image in an arbitrary direction. Further, as shown in FIGS. 10 and 11, it is possible to display a combination of perspective images of different perspective image regions. For example, a plurality of LAT images can be displayed in an overlapping manner, or LAT images and AP images having different sizes can be displayed in an overlapping manner.

  FIG. 14 is a diagram showing that the boundary of the X-ray path from the X-ray tube focal point to the detector is superimposed on the X-ray fluoroscopic image. A fluoroscopic image is formed by an X-ray beam that spreads in a cone-beam shape from a focal point toward a detector, based on a difference in X-ray absorption due to a difference in structure on the path. Positioning is difficult because the traveling direction of the beams is not parallel beams. Therefore, the model of the X-ray path is displayed so as to be superimposed on the three-dimensional reprojection image of the subject's visible light and the fluoroscopic image of the X-ray. As a result, the range in which the fluoroscopic image is obtained and the inclination of the X-ray path are clearly shown, so that positioning can be easily performed with reference to this.

  FIG. 15 is a diagram showing that a fluoroscopic image by X-rays is displayed at the position of the detector. The fluoroscopic image is obtained by detecting the result of X-ray absorption of all structures on the X-ray path by a detector. Therefore, the image is displayed here.

  FIG. 16 is a diagram showing that a fluoroscopic image by X-rays is displayed at an arbitrary position on the X-ray path. The fluoroscopic image can be logically arranged at an arbitrary position on the X-ray path, and can be arranged at an arbitrary position. Such an operation can be performed independently for all X-ray fluoroscopic images that can be superimposed and displayed.

  FIG. 17 is a diagram showing that an image within the contour of the subject is generated in a fluoroscopic image using X-rays, and this is superimposed and displayed on the visible light three-dimensional reprojection image of the subject. Necessary information in the fluoroscopic image is concentrated inside the contour of the subject, and it is possible to express only useful information by extracting and displaying only this.

  FIG. 18 is a diagram showing the arrangement of the camera 8 with respect to the scanner 1 in the measuring apparatus shown in FIG. The camera 8 is disposed at a position shifted by a height s vertically upward from the focal point of the X-ray tube 11. When the chair is moved upward by the height s, a visible light image from the same height as the image viewed from the focal position of the X-ray tube 11 can be obtained by the camera 8. Further, by making the focal length of the camera wider than that of the X-ray imaging system, a visible light three-dimensional reprojection image in a desired range can be obtained without moving the chair. The camera 8 takes a picture in synchronization with the rotation angle of the scanner 1. 360 degree rotation imaging around the subject 7 is performed, and a plurality of angle synchronous rotation imaging images are obtained.

  Since the imaging position and the collimator 2 can be set by combining the visible light image from the camera 8 arranged in the scanner 1 and the X-ray fluoroscopic image, the operability in the scan plan can be improved. Since a visible three-dimensional visible light image of the human body surface and an X-ray fluoroscopic image having internal structure information are used in combination, accurate and reliable positioning can be performed without loss of time. In addition, even if the image size is small, a wide-angle camera can be used to construct a visible light three-dimensional reprojection image, so that the imaging range can be determined without being greatly influenced by the level of proficiency of the examiner without depending on experience or intuition. .

  As shown in FIG. 18, when there is a vertical shift of a distance s between the focal point of the camera 8 and the focal point of the X-ray tube 11, the visible light imaging system and the X-ray imaging system set the rotation angle position. It also has the same rotation center axis because it is fixed to the same scanner. However, since the attachment positions of the camera 8 and the X-ray tube 11 are different in the height direction, they have different rotation planes, and the field of view range and the image matrix are also different. In view of this, the coordinate system between the visible light imaging system and the X-ray imaging system is matched using a correction phantom. Note that the details of the method for matching the coordinate systems are described in Japanese Patent Application No. 2003-416179 filed earlier, and thus the description thereof is omitted here.

  FIG. 19 is a diagram illustrating a modification of the arrangement of the X-ray tube 11, the collimator 2, and the camera 8 in the configuration of the measurement apparatus illustrated in FIG. 2. X-rays are emitted from the focal point 111 of the X-ray tube 11 toward the radiation port 112. The irradiation range of the X-rays irradiated from the radiation port 112 is narrowed by the collimator 2. A mirror 113 is disposed between the radiation port 112 and the collimator 2, and the focal point 81 of the camera 8 is disposed at a position that is a mirror image target of the focal point position 111 of the X-ray tube 11 with respect to the mirror surface. The mirror may be a half mirror. In this way, the optical axis of the camera 8 and the focal point of the X-ray tube 11 can be arranged. In this case, since the imaging result of the camera 8 is a mirror image, the CPU 4 or the like needs to invert the image in order to match the imaging result with the X-ray. In the case of the configuration of FIG. 19, parallax does not occur between the optical axis of the camera 8 and the X-ray optical axis along the radiation port 112 from the X-ray focal point 111. It is not necessary to correct the amount of parallax for the scan plan, and the cost can be reduced while improving the processing speed.

  Although the present embodiment has been described mainly with respect to dental CT that performs imaging of the tooth and jaw, the present invention relates to a CT apparatus, an X-ray C-arm apparatus, a surgical X-ray C-arm apparatus, and a mobile X-ray C. Needless to say, it can also be used for arm devices. In this case, in particular, the CT apparatus and the X-ray C-arm apparatus can effectively implement the present invention by using a transparent bed or chair.

  According to the above-described embodiment, since the imaging position and the collimator 2 can be set using the image from the camera 8 arranged on the scanner 1, the X-ray exposure of the subject 7 in the scan plan can be removed. . Since there is no X-ray exposure in this way, it is possible to perform fine adjustment by repeatedly setting the imaging position and collimator without resistance. Since real-time images are used even when fine adjustment is repeatedly performed, accurate and reliable positioning can be performed without loss of time. In addition, even if the image size is small, a wide-angle camera can be used to construct a visible light three-dimensional reprojection image, so that the imaging range can be determined without being greatly influenced by the level of proficiency of the examiner without depending on experience or intuition. .

  Since the conversion processing parameters between the coordinates of the X-ray imaging system and the coordinates of the visible light imaging system can be obtained by this method, positioning using the camera is possible, and as a result, the X-ray of the subject 7 in the scan plan is obtained. Exposure can be removed. Positioning using a camera is possible even when the rotational planes of the X-ray imaging system and the visible light imaging system are completely different by this method. For this reason, even if the image size of the X-ray imaging system is small, a wide-angle camera can be used to construct a visible light three-dimensional reprojection image. Therefore, imaging is performed without greatly affecting the proficiency level of the examiner without depending on experience or intuition. The range can be determined.

It is a figure which shows an example of the conventional X-ray tomography apparatus. An example of the hardware constitutions of the X-ray tomography apparatus of this invention is shown. It is a figure shown about the arrangement | positioning of the camera and illumination with respect to a scanner among the measuring devices shown in FIG. It is a figure which shows the process of the process which produces | generates a three-dimensional reconstruction image based on the rotation picked-up image acquired with the camera. It is a flowchart figure which shows the flow of the process which produces | generates a three-dimensional reconstruction image based on the rotation picked-up image obtained with the camera. It is a figure which shows the process of the process which produces | generates the image used for positioning by superimposing the X-ray fluoroscopic image obtained by the X-ray detector, and the visible light three-dimensional reprojection image. It is a flowchart figure which shows the flow of a process which produces | generates the image used for positioning by superimposing the X-ray fluoroscopic image obtained by the X-ray detector, and the visible light three-dimensional reprojection image. It is a figure which shows an example of a visible light three-dimensional projection image. It is a figure which shows an example at the time of displaying the fluoroscopic image by X-rays on the visible light three-dimensional projection image of FIG. It is a figure which shows the relationship of relative movement of a camera system coordinate system and an X-ray measurement system coordinate system. It is a figure which shows the relationship of the change of the visual field size of a detector, or the visual field size by a collimator. It is a figure which shows displaying only the fluoroscopic image of a LAT direction among the fluoroscopic images by X-rays, and superimposing on the visible light three-dimensional reprojection image of a subject. It is a figure which shows displaying only the fluoroscopic image of AP direction among the fluoroscopic images by X-rays, and superimposing on the visible light three-dimensional reprojection image of a subject. It is a figure which shows displaying the boundary of the X-ray path from an X-ray tube focus to a detector on a fluoroscopic image by X-rays. It is a figure which shows displaying the fluoroscopic image by a X-ray in the position of a detector. It is a figure which shows displaying the fluoroscopic image by an X-ray in arbitrary positions on an X-ray path. It is a figure which shows producing | generating the image in a to-be-examined person's outline in the fluoroscopic image by a X-ray, and superimposing this on the subject's visible light three-dimensional reprojection image, and displaying it. It is a figure shown about the arrangement | positioning of the camera with respect to a scanner among the measuring devices shown in FIG. It is a figure which shows the modification of arrangement | positioning about an X-ray tube, a collimator, and a camera among the structures of the measuring device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Scanner 2 ... Collimator 3 ... Chair 4 ... Image processing part 5 ... Display apparatus 6 ... External input device 7 ... Subject 8 ... Visible light camera 9 ... Illumination 11 ... X-ray tube 12 ... Detector 17 ... Scanner supporter DESCRIPTION OF SYMBOLS 18 ... Scanner rotating shaft 19 ... Scanner drive means 29 ... Collimator drive means 31 ... Chair support device 39 ... Chair drive means 41 ... Interface (I / F)
42 ... Memory 43 ... Hard disk 44 ... CPU
81 ... Focus 111 ... X-ray source center 112 ... Radiation port 113 ... Mirror

Claims (1)

X-ray imaging means for irradiating an X-ray from an X-ray source and imaging a subject with a detector disposed opposite the X-ray source;
Scanner rotating means for rotating the X-ray source and the detector around the subject;
Subject moving means for moving the subject;
Visible light imaging means for imaging the subject placed on the scanner rotating means;
An image processing apparatus for generating an X-ray three-dimensional reconstructed image from a projection image photographed by the X-ray photographing means by a reconstruction calculating means and reconstructing a visible light three-dimensional image from a photographing result of the visible light photographing means; ,
An X-ray tomography apparatus comprising: a display unit configured to superimpose and display the X-ray three-dimensional reconstructed image and the visible light three-dimensional image created by the image processing apparatus.

Images