JP2005021328A - X-ray tomography system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray tomography system wherein tomography and general penetrative photography can be performed. <P>SOLUTION: An X-ray tube supporting arm 22 which can rotate around a vertical axis J1 is disposed at the bottom end of a column 21 of an X-ray tube suspension device 2. An X-ray tube 1 is fixed through a rotation section 24 to a leading edge of a sliding section 23 which is slidably disposed at the X-ray tube supporting arm 22. The rotation section 24 rotates the X-ray tube 1 around a tube axis J2 and an axis J3. The X-ray tube supporting arm 22 is rotated around the vertical axis J1 and a photography apparatus 33 is rotated to be synchronized with the above rotation so that a center section 103 draws a circular orbit around the vertical axis J1 after the sliding of the sliding section 23 is stopped in the case of a circular orbit photography. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray tomography system used for medical purposes.
[0002]
[Prior art]
In X-ray tomography, X-ray imaging is performed by moving an X-ray tube in a circular motion or an elliptical motion with respect to an imaging target. At that time, an imaging device such as a flat panel is synchronized with the movement of the X-ray tube. A circular motion or an elliptical motion is performed (for example, refer to Patent Document 1). However, in an X-ray apparatus for general radiography, the X-ray tube and the imaging apparatus cannot be moved in such a complicated manner. Therefore, an X-ray imaging apparatus for performing tomography is configured exclusively for tomography. .
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-136509
[Problems to be solved by the invention]
However, since the X-ray tomography apparatus is configured exclusively for tomography, it cannot perform various types of general imaging, and at most, can perform upright position imaging. Therefore, in order to perform tomography and general imaging, it is necessary to separately prepare an X-ray imaging apparatus dedicated to tomography and an X-ray imaging apparatus for general imaging.
[0005]
The present invention provides an X-ray tomography system capable of performing tomography and general fluoroscopic imaging.
[0006]
[Means for Solving the Problems]
The X-ray tomography system according to the first aspect of the present invention includes an X-ray tube that emits X-rays toward a subject and an X-ray tube, and the X-ray tube is disposed around the tube axis and in a horizontal plane. A first rotating device that rotates about an orthogonal axis orthogonal to the axis, a horizontal moving device that horizontally moves the first rotating device one-dimensionally, a second rotating device that rotates the horizontal moving device about a vertical axis, and horizontal movement A vertical movement device that moves the device up and down in the vertical direction, an XY movement device that horizontally moves the first rotation device, the second rotation device, the horizontal movement device, and the vertical movement device integrally in two dimensions, and a heaven on which the subject is placed And an imaging table having an X-ray imaging device that can move horizontally in a two-dimensional manner.
According to a second aspect of the present invention, in the X-ray tomography system according to the first aspect, the X-ray imaging apparatus is rotated about the vertical axis in conjunction with the rotation of the horizontal movement apparatus by the second rotation apparatus. Rotational orbit tomography is performed.
According to a third aspect of the present invention, in the X-ray tomography system according to the first aspect, the horizontal movement device is rotated by the second rotation device while the horizontal movement is performed by the horizontal movement device, and the horizontal movement and rotation thereof are performed. In this manner, the X-ray imaging apparatus is swirled around the vertical axis to perform spiral orbit tomography.
An X-ray tomography system according to a fourth aspect of the present invention is provided with an X-ray tube that emits X-rays toward a subject and an X-ray tube, and the X-ray tube is disposed around the tube axis and in a horizontal plane. A rotating device that rotates around an orthogonal axis orthogonal to the axis, a vertical moving device that moves the rotating device up and down in the vertical direction, an XY moving device that horizontally moves the rotating device and the vertical moving device integrally, and a test And an imaging table having an X-ray imaging device that can move horizontally in a two-dimensional manner.
According to the fifth aspect of the present invention, in the X-ray tomography system according to the fourth aspect, the XY moving device rotates the rotating device and the vertical moving device integrally around the vertical axis passing through the center of the tomography. In conjunction with this, the X-ray imaging apparatus is rotated about the vertical axis to perform rotational orbit tomography.
According to a fifth aspect of the present invention, in the X-ray tomography system according to the fourth aspect of the present invention, the rotating device and the vertical moving device are swirled integrally around the vertical axis passing through the center of the tomography by the XY moving device. In conjunction with the movement, the X-ray imaging apparatus is swirled around the vertical axis to perform spiral trajectory tomography.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
-First embodiment-
FIG. 1 is a diagram showing a first embodiment of an X-ray tomography system according to the present invention, and shows a schematic configuration of the system. The imaging system shown in FIG. 1 displays an overhead traveling X-ray tube suspension 2 provided with an X-ray tube 1, a lying position imaging table 3 for imaging a subject in a lying state, and imaging results. And a control device 5 that controls the entire system.
[0008]
The X-ray tube suspension 2 can be electrically moved on the movable rail 6 in the y direction. Further, the movable rail 6 can be electrically moved in the x direction on a fixed rail 7 extending in the x direction. As a result, the X-ray tube suspender 2 can freely move in the x direction and the y direction.
[0009]
The X-ray tube suspender 2 includes a support column 21 that can be expanded and contracted in the vertical direction (z direction) and an X-ray tube holding arm 22 that is provided at the lower end and extends horizontally. The X-ray tube holding arm 22 can rotate about the axis J1 in the vertical direction as a rotation axis, and has a slide portion 23 that slides in the horizontal direction so as to move forward and backward from the X-ray tube holding arm 22. The X-ray tube 1 is provided at the distal end of the slide part 23 via a rotating part 24. The rotating unit 24 can rotate the X-ray tube 1 with the tube axis J2 as a rotation axis, and can rotate with an axis J3 orthogonal to the tube axis J2 in the horizontal plane (xy plane) as a rotation axis. The vertical movement of the support column 21, the rotation of the X-ray tube holding arm 22, the sliding movement of the slide portion 23, and the rotation of the X-ray tube 1 with respect to the axes J2 and J3 are performed by electric drive by an electric motor or the like.
[0010]
The lying position imaging table 3 has a top plate 31 on which a subject to be imaged is placed, and a lifting platform 32 that supports the top plate 31 and moves up and down. The top plate 31 can be manually moved in the x direction and the y direction with respect to the lifting platform 32. In FIG. 1, a part of the top plate 31 is shown in a broken section so that the structure on the lower side of the top plate 31 can be easily understood. Note that the recumbent photographing table 3 does not have to be liftable.
[0011]
An imaging device 33 for capturing an X-ray fluoroscopic image of the subject is provided below the top plate 31. The panel-shaped imaging device 33 is attached to an XY driving device 34 that drives it in the x and y directions. The XY driving device 34 is provided with a mounting portion 341 to which the imaging device 33 is mounted. The mounting unit 341 drives the imaging device 33 in the y direction, and the mounting unit 341 itself can move on the guide rail 342 in the x direction. As a result, the imaging device 33 can be moved two-dimensionally in the xy plane by the XY driving device 34.
[0012]
A flat panel X-ray detector is used in the imaging apparatus 33 shown in FIG. The flat panel X-ray detector detects an X-ray fluoroscopic image of a subject generated by X-ray irradiation of the X-ray tube 1 and converts it into an electrical signal. A detection element for detecting X-rays is two-dimensional. Many are arranged in a matrix. Reference numeral 103 denotes a center position of the imaging device 33.
[0013]
The movement of the entire X-ray tube suspender 2 in the x and y directions, the expansion / contraction, sliding and rotating operations in the X-ray tube suspender 2, the raising / lowering operation in the lying position imaging table 3, and the two-dimensional movement operation of the imaging device 33 are as follows: Control is performed by the imaging control unit 51 of the control device 5. The imaging control unit 51 performs the above-described various operations based on instructions from the operation unit 52.
[0014]
The detection signal from the imaging device 33 is input to the image processing unit 531 of the data processing unit 53, and the image information is processed. For example, a tomographic image is formed. The image information processed by the image processing unit 531 is stored in the image information storage unit 532. The image information stored in the image information storage unit 532 can be appropriately displayed on the display device 4 as a display image.
[0015]
Next, the driving mode of the apparatus will be described by taking a specific photographing operation as an example. In the X-ray tomography system of the present embodiment, as in a general multi-orbit tomography apparatus, tomography can be performed using each of the imaging trajectories of a circular trajectory, a spiral trajectory, a perfect circular intermittent trajectory, and a linear trajectory. In the following, in the case of circular orbit imaging, the drive mode of each device will be described in detail along the imaging procedure, and the outline of other orbit imaging will be described.
[0016]
《Circular orbit shooting》
(1) The subject M is placed on the top board 31 of the supine imaging table 3, and the horizontal positions of the imaging region 100 of the subject M and the center of the imaging device 33 coincide as shown in FIG. The top plate 31 is moved manually so as to.
(2) Raise and lower the elevating platform 32 of the lying position photographing table 3 to a predetermined height. However, this process is omitted when a non-liftable imaging table is used.
(3) As shown in FIG. 2B, the movable rail 6 on the fixed rail 7 is moved in the x direction (negative direction), and the X-ray tube suspension 2 on the movable rail 6 is moved in the y direction (positive direction). The vertical axis J1 that is the central axis of the support column 21 and the center of the imaging device 33 are made to coincide with each other.
[0017]
(4) As shown in FIG. 3, the support column 21 is moved up and down to set the FFD necessary for photographing. FFD is the distance between the X-ray focal point of the X-ray tube 1 and the image receiving surface of the imaging device 33. For example, FFD = 1 (m) is set.
(5) The slide portion 23 of the X-ray tube holding arm 22 is slid to set the angle θ between the straight line connecting the X-ray focal point and the imaging region 100 and the vertical line to a predetermined tomographic angle (see FIG. 3). .
(6) The X-ray tube 1 is rotated around the tube axis J2, and the X-ray cone axis J4 is aligned with the tomographic center C of the imaging region 100 (see FIG. 3).
(7) The imaging start switch (not shown) provided in the operation unit 52 (see FIG. 1) of the control device 5 is operated to start tomographic imaging by circular orbit imaging.
[0018]
FIG. 4 is a diagram showing the movement of the X-ray tube 1 and the imaging device 33 during circular orbit imaging. When the imaging start switch is turned on, the X-ray tube suspender 2 starts rotating the X-ray tube holding arm 22 with the vertical axis J1 as a rotation axis. At this time, the slide unit 23 holds a predetermined amount of feeding. At the same time, the XY driving device 34 is driven in synchronization with the rotation of the X-ray tube holding arm 22 to rotate the imaging device 33 so that the center 103 of the imaging device 33 draws a circular orbit 102 around the axis J1.
[0019]
101 shows the trajectory of the X-ray focal point of the X-ray tube. If the rotational angular velocity is ω (rad / t) and the tomographic center C is the origin of the x and y coordinates, the trajectory of the X-ray focal point (x1, y1) can be expressed as x1 = R1 · cos (ωt) and y1 = R1sin (ωt). On the other hand, the trajectory 102 (x2, y2) drawn by the center 103 of the imaging device 33 is expressed as x2 = R2 · cos (ωt + π), y2 = R2 · sin (ωt + π). That is, the y-direction drive of the imaging device 33 by the mounting portion 341 is performed as y2 = R2 · sin (ωt + π), and at the same time, the x-direction driving of the mounting portion 341 itself on the guide rail 342 is x2 = R2 · cos ( ωt + π).
[0020]
R1 and R2 are the radii of the circular orbits 101 and 102. If the height of the tomographic center C from the image receiving surface of the imaging device 33 is h, since “R1: R2 = (FFD−h): h”, R2 = R1 · h / (FFD−h).
[0021]
(8) When the X-ray tube suspension 2 and the imaging device 33 come to move synchronously at a predetermined speed, X-ray exposure is started.
(9) If the X-ray exposure is completed for one round of the circular motion, for example, when the X-ray exposure starts from A in FIG. 4 and makes one turn of A → B → D → E → A, the exposure is stopped. Then, the circular motion of the X-ray tube suspender 2 and the imaging device 33 is finished, and each is returned to the initial position.
[0022]
FIG. 5 is a diagram for explaining the height change of the fault center. As shown by the solid line, when the feed amount of the slide portion 23 and the rotation angle with respect to the tube axis J2 of the X-ray tube 1 are set, C1 becomes the center of the fault. The angle formed by the X-ray cone axis J4 and the axis J1 (that is, the tomographic angle) is θ1. When the tomographic center is changed to C2 from this state, the slide part 23 is extended by L1 so that the tomographic angle θ2 is obtained. Then, it is rotated by an angle α around the tube axis J2 of the X-ray tube 1 so that the X-ray cone axis J4 is aligned with the tomographic center C2. In the example shown in FIG. 5, the X-ray focal point is on the tube axis J2.
[0023]
《Straight circle orbit shooting》
In the circular orbit imaging described above, the X-ray exposure is performed for one round of circular motion, but in the true circular intermittent orbit imaging, the exposure is performed at a predetermined angle (for example, 120 degrees) as shown in FIG. Areas 110 a and 110 b on the trajectory 101 represent areas where X-ray exposure is performed by the X-ray tube 1. When X-ray exposure is performed in the region 110a in the angle range 120 deg on the trajectory 101, the imaging device 33 moves the region 120a on the trajectory 102 during the X-ray exposure. Further, while the X-ray focal point moves in the area 110b, the center of the imaging device 33 moves in the area 120b.
[0024]
《Swirl Orbit Shooting》
In the case of the circular orbit imaging described above, the X-ray tube suspension 2 is rotated about the vertical axis J1 while keeping the feeding amount of the slide portion 23 constant as shown in FIG. In this case, as shown in FIG. 7, the slide portion 23 is fed out at a constant speed while rotating the X-ray tube suspension 2. By doing so, the trajectory 101 of the X-ray focus becomes spiral. On the other hand, the XY driving device 34 is also controlled with respect to the imaging device 33 so that the center 103 forms the spiral trajectory 102 in synchronization with the spiral motion of the X-ray focus.
[0025]
When performing spiral trajectory imaging while changing the feed amount of the slide portion 23, the X-ray cone is rotated around the tube axis J2 (angle α) simultaneously with the feed operation as shown in FIG. Control is performed so that the axis J4 always passes through the fault center C.
[0026]
《Straight line shooting》
FIG. 9 is a diagram for explaining linear trajectory imaging. In the example shown in FIG. 6, the X-ray tube suspension 2 is moved in the x direction to perform linear trajectory imaging. At this time, in synchronization with the movement of the X-ray tube suspension 2 in the positive x direction, the imaging device 33 is moved in the positive x direction so that the X-ray cone axis J4 always passes through the center 103 of the imaging device 33. Further, during the linear trajectory imaging, the X-ray tube 1 is rotated around the axis J3 so that the X-ray cone axis J4 always passes through the tomographic center C.
[0027]
As described above, in the X-ray tomography system according to the present embodiment, the overhead traveling X-ray tube suspender 2 is configured as shown in FIG. 1 and the X-ray tube suspender 2 is moved. By performing synchronous drive control in conjunction with the moving operation of the imaging device 33 provided on the supine imaging table 3, it is possible to perform tomographic imaging similar to a conventional tomographic dedicated device.
[0028]
Further, the subject M is placed on the top plate 31, the position of the imaging device 33 is fixed, and X-ray exposure is performed from above or obliquely, thereby performing general imaging like a normal X-ray fluoroscopy device. You can also. Furthermore, as shown in FIG. 10, by using a photographing table 131 that can put a subject M placed on the top board 130 in a substantially standing state, not only general photographing in a lying state is performed. Standing photography can also be performed easily.
[0029]
-Second Embodiment-
FIG. 11 is a diagram showing a second embodiment of the X-ray tomography system according to the present invention, and is a schematic configuration diagram similar to the case of FIG. Compared to the system shown in FIG. 1, the structure shown in FIG. 11 differs from the X-ray tube suspension 2 of the system shown in FIG. The other parts except for the X-ray tube suspender 200 are the same as those in the system of FIG. 1, and the following description will focus on the X-ray tube suspender 200 portion.
[0030]
The X-ray tube suspension 200 includes a support column 21 that extends vertically and an X-ray tube holding arm 222 that is provided at the lower end of the support column 21 and extends horizontally. The X-ray tube 1 is provided at the distal end of the X-ray tube holding arm 222 via the rotating unit 24. The rotating unit 24 can rotate the X-ray tube 1 with the tube axis J2 as a rotation axis, and can rotate with an axis J3 orthogonal to the tube axis J2 in the horizontal plane (xy plane) as a rotation axis.
[0031]
Also in the X-ray tomography system of the second embodiment, as in the first embodiment, tomography using a circular orbit, spiral orbit, perfect circular intermittent or linear imaging trajectory, and standing General shooting including shooting can be performed. Note that the imaging operation in linear orbit imaging and standing imaging is exactly the same as in the first embodiment, and thus description thereof is omitted. In the following, circular orbit imaging, spiral orbit imaging, and perfect circle intermittent orbit imaging will be described.
[0032]
《Circular orbit shooting》
In the case of circular orbit imaging, the procedure from placing the subject M on the top plate 31 and moving the column 21 of the X-ray tube suspension 200 up and down to set the FFD is the procedure of the first embodiment described above. This is the same as (1) to (4).
(5) As shown in FIG. 12, the movable rail 6 is driven in the x direction (longitudinal direction of the top plate 31) with respect to the fixed rail 7, and the X-ray tube suspension 200 is moved to a predetermined tomography start position, that is, Move to a position where a predetermined tomographic angle θ is obtained. At the same time, the imaging device 33 is moved by a predetermined amount in the direction opposite to the moving direction of the X-ray tube suspension 200. In the example shown in FIG. 12, the X-ray tube suspension 200 is moved in the x negative direction and the imaging device 33 is moved in the x positive direction, but may be moved in opposite directions.
(6) The X-ray tube 1 is rotated around the axis J3 so that the X-ray cone axis J4 passes through the fault center C.
(7) The imaging start switch (not shown) of the operation unit 52 (see FIG. 11) is turned on to start tomographic imaging by circular orbit imaging.
[0033]
FIG. 13 is a plan view showing the moving operation of the X-ray tube suspension 200 during circular orbit imaging. Reference numeral 101 denotes an orbit of the X-ray focal point, which is a circular orbit centered on the fault center C. In the second embodiment, the movement of the movable rail 6 in the x direction on the fixed rail 7 and the movement of the X-ray tube suspension device 200 in the y direction on the movable rail 6 are controlled synchronously, thereby producing an X-ray. The focus trajectory is set to be the circular trajectory 101.
[0034]
For example, if the trajectory 101 of the X-ray focal point is expressed as x1 = R1 · cos (ωt) and y1 = R1sin (ωt) as in the first embodiment, the trajectory 104 of the central axis of the column 21 is x3 = R1 · cos (ωt), y3 = d + R1sin (ωt). That is, the driving of the X-ray tube suspension device 2 in the x direction and the y direction may be controlled so that the locus 104 of the central axis of the column 21 becomes (x3, y3).
[0035]
Further, in synchronization with the circular motion of the X-ray tube suspension 200, the rotation of the X-ray tube 1 around the tube axis J2 and the axis J3 is controlled so that the X-ray cone axis J4 always passes the fault center C. To do. Since the movement control of the imaging device 33 is the same as in the first embodiment, a description thereof is omitted here.
[0036]
In the case of perfect circle intermittent orbit imaging, the rotational drive method of the X-ray tube suspension 200 is the same as in the circular orbit imaging described above, and X-ray exposure is performed in a predetermined region 101a of the orbit 101 as shown in FIG. , 101b only. In the case of spiral trajectory imaging, if the movement of the X-ray tube suspender 200 in the x and y directions is controlled so that the trajectory 104 of the column is spiral, the trajectory of the X-ray focus also becomes a spiral trajectory. Furthermore, application to the case of general imaging can also be performed in the same manner as in the first embodiment.
[0037]
In the correspondence between the embodiment described above and the elements of the claims, the rotating unit 24 is the first rotating device and the rotating device of claim 4, the slide unit 23 is the horizontal moving device, and the X-ray tube holding arm 22. Constitutes a second rotating device, and the column 21 constitutes a vertical movement device. In addition, the present invention is not limited to the above embodiment as long as the characteristics of the present invention are not impaired.
[0038]
【The invention's effect】
As described above, according to the present invention, not only tomography but also general fluoroscopic imaging can be performed by one X-ray tomography system.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of an X-ray tomography system according to the present invention, and shows a schematic configuration of the system.
FIG. 2 is a plan view for explaining the operation of the X-ray tomography system, in which the X-ray tube suspension 2 is moved in the order of (a) and (b).
FIG. 3 is a diagram for describing a photographing operation procedure, and is a view of the photographing system as viewed from the X positive direction.
FIG. 4 is a diagram illustrating the movement of the X-ray tube 1 and the imaging device 33 during circular orbit imaging.
FIG. 5 is a diagram illustrating a change in height of a fault center.
FIG. 6 is a diagram for explaining X-ray exposure in perfect circular intermittent orbit imaging.
FIG. 7 is a diagram illustrating spiral trajectory imaging.
FIG. 8 is a diagram illustrating the extension of the slide unit 23 and the rotation around the tube axis J2 during spiral trajectory imaging.
FIG. 9 is a diagram for explaining linear trajectory imaging.
FIG. 10 is a diagram for explaining standing shooting.
FIG. 11 is a diagram showing a second embodiment of the X-ray tomography system according to the present invention, and shows a schematic configuration of the system.
12 is a diagram for explaining the movement of the X-ray tube suspension 200 to a tomographic start position. FIG.
FIG. 13 is a plan view showing the moving operation of the X-ray tube suspension device 200 during circular orbit imaging.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 X-ray tube 2,200 X-ray tube suspender 3 Supine imaging table 4 Display apparatus 5 Control apparatus 6 Movable rail 7 Fixed rail 21 Support | pillar 22, 222 X-ray tube holding arm 23 Slide part 24 Rotating part 33 Imaging apparatus 34 XY Drive device

Claims (6)

An X-ray tube that emits X-rays toward the subject;
A first rotating device provided with the X-ray tube and rotating the X-ray tube around a tube axis and an orthogonal axis perpendicular to the tube axis in a horizontal plane;
A horizontal movement device that horizontally moves the first rotation device in a one-dimensional manner; a second rotation device that rotates the horizontal movement device around a vertical axis;
A vertical movement device for moving the horizontal movement device up and down in the vertical direction;
An XY moving device that horizontally moves the first rotating device, the second rotating device, the horizontal moving device, and the vertical moving device in a two-dimensional manner;
An X-ray tomography system comprising: a top plate on which a subject is placed; and an imaging table having an X-ray imaging apparatus capable of two-dimensional horizontal movement. The X-ray tomography system according to claim 1,
X-ray tomography characterized in that rotational orbit tomography is performed by rotating the X-ray imaging device about the vertical axis in conjunction with rotation of the horizontal movement device by the second rotation device. system. The X-ray tomography system according to claim 1,
The horizontal moving device is rotated by the second rotating device while being horizontally moved by the horizontal moving device, and the X-ray imaging device is swirled around the vertical axis in conjunction with the horizontal movement and rotation. An X-ray tomography system characterized in that swirling orbit tomography is performed. An X-ray tube that emits X-rays toward the subject;
A rotating device provided with the X-ray tube, and rotating the X-ray tube around a tube axis and an orthogonal axis orthogonal to the tube axis in a horizontal plane;
A vertical movement device for moving the rotation device up and down in the vertical direction;
An XY movement device that horizontally moves the rotation device and the vertical movement device integrally;
An X-ray tomography system comprising: a top plate on which a subject is placed; and an imaging table having an X-ray imaging apparatus capable of two-dimensional horizontal movement. The X-ray tomography system according to claim 4,
The X-ray imaging device is rotated about the vertical axis in conjunction with the rotation while rotating the rotation device and the vertical movement device integrally around the vertical axis passing through the center of the tomography by the XY movement device. X-ray tomography system characterized in that rotational orbit tomography is performed. The X-ray tomography system according to claim 4,
The X-ray imaging device is swirled around the vertical axis in conjunction with the swirling movement while the rotating device and the vertical moving device are swirled together around the vertical axis passing through the center of the fault by the XY moving device. An X-ray tomography system characterized in that swirling orbit tomography is performed.

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