JP4474761B2 - X-ray fluoroscopy table - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray fluoroscopic table, and more particularly to an overtube type X-ray fluoroscopic table that performs imaging by obliquely injecting an X-ray beam in a direction perpendicular to the body axis direction of a subject.
[0002]
[Prior art]
The upper tube type X-ray fluoroscopic table has an X-ray tube above the top plate, spot imaging and imaging systems are under the top plate, and the X-ray tube is located away from the top plate. Large space, easy to change the subject's position, etc., and good diagnostic efficiency. Since the upper space is wide, it is convenient when various diagnoses (for example, myelography, IVR) are performed on the subject or when other diagnoses (for example, endoscopic diagnosis, ultrasonic diagnosis, etc.) are used in combination. In addition, the heavy spot photographing device is easily held under the top plate.
As shown in FIG. 3, the X-ray fluoroscopic imaging table has an X-ray movable diaphragm 2 attached to a radiation port of an X-ray tube 1 held by a support arm 7 from a support column 9. The line is focused on the X-ray beam 3. Then, the subject 4 is placed on the top plate 5, and the image intensifier or flat panel image receiving device 6 is attached to the holding unit 8 on the back surface of the top plate 5, and the whole is supported by the support unit 10. . Then, in a state where the X-ray tube 1 and the image receiving device 6 are arranged to face each other with the top plate 5 interposed therebetween, the support column 7 and the holding unit 8 are linked by the support column 9 so that the X-ray beam 3 is covered. The examiner 4 is irradiated vertically.
[0003]
FIG. 4 shows the structure of the movable diaphragm 2 for X-rays. The role of the X-ray movable diaphragm 2 for adjusting the X-ray irradiation field is to reduce the exposure dose and improve the image quality. X-rays from the focal point 1a of the X-ray tube 1 are the focal points of the lower blades 26 and 27 and the pyramid restricting blades 36 and 39 (also referred to as upper blades) that restrict the left and right front and rear X-rays provided on the movable diaphragm 2. The X-ray beam 3 is irradiated to the diagnosis site of the subject 4 by the three-stage blades of the outer X-ray reduction blades 21 and 22 (also referred to as back blades).
Line cone control blades 36 and 39 (also referred to as upper blades) mainly made of a lead plate set the utilization line cone to the minimum necessary X-ray irradiation field. There are two methods for driving the blades: arc movement by a gear and a link mechanism, or parallel movement by a wire rope, a pulley, and a shaft arranged in parallel. The former has a simple mechanism, and the latter has a set X. The accuracy of the radiation field is good.
The lower blades 26 and 27 and the out-of-focus X-ray reduction blades 21 and 22 (also referred to as back blades) operate in conjunction with the line cone control blades 36 and 39. A small motor is used for driving. The lower blades 26 and 27 greatly contribute to the reduction of scattered radiation and the leakage dose of the movable diaphragm, and the out-of-focus X-ray reduction blades 21 and 22 are blades that effectively reduce out-of-focus X-rays.
In addition to the individual performances of the above three sets of blades, the overall performance is determined by the mutual geometric relationship and assembly dimensional accuracy.
The display of the X-ray irradiation field includes a method in which a light irradiation field formed by the light emitted from the irradiation lamp 28 passing through the mirrors 29 and 30 and the pyramid limiting blades 36 and 39 is visually observed on the subject 4, There are two methods in which the pointer 33 interlocked with the conical restriction blades 36 and 39 indicates the scale plate 34 of the X-ray irradiation field and displays the opening degree, and it can be confirmed without emitting X-rays. However, there are some that do not include the irradiation lamp 28. Moreover, in order to protect the total filtration which prescribes | regulates the quality of X-ray | X_line, the removable filter 25 etc. which can be attached or detached are provided.
In recent years, a flat panel image receiving device 6 using a semiconductor X-ray surface sensor has been developed in place of an X-ray film or an imaging plate used in a simple X-ray imaging apparatus. This X-ray surface sensor is usually composed of an X-ray conversion film that converts X-rays into light, a photodiode array arranged in a matrix immediately below, and a TFT switch connected to each photodiode array, After X-ray irradiation, each TFT switch is turned on sequentially to read out the signal charge accumulated in each pixel and form an X-ray image, and directly output a charge signal that responds to radiation and corresponds to the incident dose A radiation sensor array consisting of a conversion layer is arranged, arranged in a matrix directly below it, TFT switches are connected to the electrodes, and each TFT switch is turned ON at the time of irradiation, thereby reading out the signal charge accumulated in each pixel There are two types that form X-ray images. Here, the latter type will be described.
[0004]
FIG. 5 shows the structure of a flat panel image receiving device 6 having the latter type of X-ray conversion layer 12. In this flat panel image receiving device 6, a bias voltage is supplied to the X-ray conversion layer 12 from the upper electrode 11, and the TFT 15 is applied to the pixel electrodes 13 arranged in a matrix on the active matrix substrate 16 immediately below the X-ray conversion layer 12. The switch elements of the TFTs 15 are sequentially turned on by the gate driver circuit 17 via the FPC (Flexible Printed Circuit: printed wiring board using a flexible insulating substrate) 20 at the time of irradiation. The signal charges stored in the storage capacitor 14 of each pixel are read out to the amplifier circuit 18 via the FPC 19. Then, the signal is input from the amplifier circuit 18 to the TV circuit via the A / D converter, signal processing is performed in the TV circuit, and an X-ray image is displayed on the monitor.
[0005]
The X-ray conversion layer 12 has good photoconductive characteristics according to the X-ray irradiation intensity, and generates a charge signal. For example, it is easy to form a large area by vapor deposition, and amorphous selenium (a-Se) or the like having a thickness of 300 to 600 μm is used. An upper electrode 11 of the X-ray conversion layer 12 is formed on the surface on the X-ray incident side, and a pixel electrode 13 is formed at a position corresponding to each pixel on the side opposite to the X-ray incident side.
The storage capacitor 14 is connected between the pixel electrode 13 and the ground. Then, a bias voltage is applied from the bias application unit to the X-ray conversion layer 12, and charges generated in the X-ray conversion layer 12 according to the X-ray irradiation intensity are stored in the capacitor of the storage capacitor 14.
A transistor switch, for example, a TFT 15 having a signal readout switch function, is arranged two-dimensionally for each pixel, and the charge signal of the storage capacitor 14 is read out to the amplifier circuit 18 by the switch pulse from the gate driver circuit 17.
[0006]
[Problems to be solved by the invention]
The conventional X-ray fluoroscopic imaging table is configured as described above. However, in an overtube type apparatus, an image system (an X-ray tube 1 and an image intensifier, a time-lapse imaging apparatus, or an image receiving apparatus such as a flat panel). 6) is fixed in a direction orthogonal to the body axis of the subject 4 (in the body side direction) and cannot move, so it is difficult to irradiate X-rays from an oblique direction. In order to realize this, there is a device that implements oblique imaging by mechanically separating the X-ray tube 1 and the image receiving device 6 (such as an image intensifier, a rapid photographing device, or a flat panel). In order to realize the irradiation with X-rays, means for moving the X-ray tube 1 in the body side direction (perpendicular to the body axis) and means for rotating in the body side direction are required. However, in order to realize these functions, the structure of the holding portion that moves the support arm 7 that holds the X-ray tube 1 or rotates the X-ray tube 1 becomes complicated, and is heavy in terms of mass. There is a problem that the device structure becomes complicated due to the increase in size.
[0007]
The present invention has been made in view of such circumstances, and realizes an X-ray oblique insertion function in a direction perpendicular to the body axis (body side direction) simply and without complicating the device structure. An object of the present invention is to provide an X-ray fluoroscopic table that can be used.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the X-ray fluoroscopic imaging table of the present invention is disposed opposite to the back side of the top plate with the X-ray tube provided in front of the subject on the top plate and the subject interposed therebetween. In an overtube type X-ray fluoroscopic imaging table having a flat panel image receiving device, the X-ray tube is attached to the X-ray tube emission port so that the X-ray beam moves in a direction perpendicular to the body axis direction of the subject. Blade driving means for independently operating the left and right blades in the movable diaphragm, and top plate interlocking means for taking in the operation information of the left and right blades and moving the top plate to the left and right in conjunction with the movement of the X-ray beam. Is.
[0010]
The X-ray fluoroscopic imaging table of the present invention is configured as described above. In an overtube apparatus equipped with a flat panel image receiving device, the left and right blades provided in the X-ray movable diaphragm are independently provided. An X-ray beam is examined from a direction perpendicular to the body axis direction of the subject by providing vane driving means to be operated and top plate interlocking means that moves the top plate to the left and right according to the operation of the blade. It is possible to obliquely enter a person and to perform oblique imaging.
A rotating means for rotating the X-ray tube attached to the support arm in a direction perpendicular to the body axis direction of the subject; and a top board interlocking means for moving the top board to the left and right according to the rotation angle. The X-ray beam can be obliquely introduced into the subject from a direction orthogonal to the body axis direction of the subject, and oblique imaging can be performed.
With the mechanism as described above, the X-ray oblique insertion function in the direction orthogonal to the body axis (body side direction) can be realized simply and without complicating the apparatus structure.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the X-ray fluoroscopic imaging table of the present invention will be described with reference to FIG. FIG. 1 shows a cross section perpendicular to the body axis of the X-ray fluoroscopic imaging table of the present invention, and shows the relationship among the movable diaphragm 2, the top plate 5, and the image receiving device 6. (A) shows a normal state in which the subject 4 is imaged at the center of the image receiving device 6, and (b) shows that the subject 5 is moved from the center to the left by the distance A and the top 5 is moved. The oblique imaging state in which the left and right blades 2a and 2b are respectively moved to the left, (c) is the left and right blades of the movable diaphragm 2 when the subject 5 is moved from the center to the right by the distance A by the distance A. It is a figure which shows the oblique insertion imaging state which moved 2a and 2b to the right, respectively.
The X-ray fluoroscopic imaging table includes an X-ray tube 1 positioned in front of the subject 4 on the top plate and a flat panel image arranged opposite to the back side of the top plate 5 across the subject 4. The left and right blades 2a and 2b in the movable diaphragm 2 attached to the X-ray tube radiating port are independently used so that the X-ray beam 3 moves in a direction perpendicular to the body axis direction of the subject 6 and the subject 4. It is composed of blade driving means to be operated and top plate interlocking means for taking in the operation information of the left and right blades 2a and 2b and moving the top plate 5 to the left and right in conjunction with the movement of the X-ray beam 3.
[0012]
The left and right blades 2a and 2b in the movable diaphragm 2 attached to the radiation port of the X-ray tube 1 are line-cone restricting blades (upper blades) 39 and 36, lower blades 27 and 26 and out-of-focus X-rays shown in FIG. This is a general term for blades composed of three stages of reduction blades (back blades) 21 and 22. Each of the three stages of blades has a cone 31, a pointer 33, and a scale plate 34 provided on the movable diaphragm 2 in the front, and a pyramidal restriction blade (upper blade) 39, a lower blade 27, and an out-of-focus X-ray. A reduction blade (back blade) 21 is provided, and a line cone restriction blade (upper blade) 36, a lower blade 26, and an out-of-focus X-ray reduction blade (back blade) 22 are provided in the front and rear. The left and right blades and the front and rear blades are driven independently, but the upper and lower blades move in conjunction with each other. The left and right blades (the left and right blades of the conical restriction blade 39, the left and right blades of the lower blade 27, and the left and right blades of the out-of-focus X-ray reduction blade 21) are independent on the left and right. Then, it is driven by the blade driving means. The blade 2a shown in FIG. 1 is a general term for the left blade of the left blade of the conical restriction blade 39, the left blade of the lower blade 27, and the left blade of the out-of-focus X-ray reduction blade 21, and the blade 2b is a conical restriction blade. This is a general term for the right blade composed of 39 right blades, the right blade of the lower blade 27, and the right blade of the out-of-focus X-ray reduction blade 21.
[0013]
The blade driving means is provided in the movable diaphragm 2 by independently driving a small motor for driving the blade 2 a and a small motor for driving the blade 2 b. A signal is sent from the controller to the small motor, and the blade 2a and the blade 2b move independently to determine a predetermined opening degree and its left and right positions. Thereby, the X-ray beam 3 can be emitted at a predetermined oblique incident angle. The X-ray beam 3 can be narrowed to a predetermined width by the blades 2a and 2b, and is controlled by a CPU provided in the controller so as not to exceed the imaging area of the flat panel image receiving device 6.
The top plate interlocking means is a horizontal movement distance and a moving speed of the top plate 5 based on two signals sent from the CPU provided in the controller to the two small motors to drive the left and right blades 2a and 2b. And the top plate 5 is moved to a predetermined position in the body side direction while maintaining a certain distance from the center of the X-ray beam 3. For example, the top 5 moves so that the center of the X-ray beam 3 and the center of the top 5 in the short direction always coincide.
[0014]
In the image receiving device 6, the flat panel image receiving device 6 having the X-ray conversion layer 12 described in FIG. 5 is incorporated in the holding unit 8, and interlocks with the X-ray tube 1. The flat panel image receiving device 6 is thin and light, and does not occupy a large space like an image intensifier. In the case of the image intensifier, image distortion occurs in the peripheral portion, the input surface is circular at the maximum, and the resolution decreases in the peripheral portion. On the other hand, the flat panel image receiving apparatus 6 has a linearity of the input surface, and can obtain an image with a uniform resolution from a wide rectangular area.
The image receiving device 6 works in conjunction with the X-ray tube 1 but does not move during oblique imaging. At that time, the X-ray image transmitted through the subject 4 enters one peripheral portion of the image receiving device 6 and the X-ray information enters the peripheral portion. However, in this X-ray fluoroscopic imaging table, the same signal as the signal sent from the controller to the small motor of the movable diaphragm 2 is sent to the TV circuit by the TV circuit of the image receiving device 6 at the time of oblique insertion imaging. The image data incident on the peripheral portion is displayed at the center of the monitor, and the same data is stored in the storage device.
[0015]
Next, the operation of the X-ray fluoroscopic imaging table will be described. First, the subject 4 is placed on the top board 5. Then, in the state shown in FIG. 1A, the irradiation lamp 28 of the movable diaphragm 2 attached to the X-ray tube 1 is turned on, and the alignment with the region of interest of the subject 4 and the irradiation field are confirmed. Then, the oblique operation switch provided on the control console is rotated to move the blades 2a and 2b of the movable diaphragm 2 so as to reach an arbitrary oblique insertion position, as shown in FIG. 1 (b) or (c). Put it in a state. When this operation is performed, the CPU provided in the controller receives a signal from the operation of the oblique insertion operation switch, calculates the horizontal movement distance and the movement speed of the top 5 calculated from the oblique insertion angle, The plate 5 is moved to a predetermined position. X-ray fluoroscopy is performed in this state, and if an X-ray image obtained by oblique insertion fluoroscopy of the region of interest to be imaged is displayed at the center of the monitor, the X-ray ON button is pressed to complete the imaging. At the time of fluoroscopy, an oblique fluoroscopic image of the region of interest of the subject 4 can be observed at the center of the monitor, and when imaging is completed, it is stored in a storage device and can be displayed on the monitor after completion.
[0016]
Next, another embodiment of the X-ray fluoroscopic imaging table of the present invention will be described with reference to FIG. FIG. 2 is a view showing a cross section in a direction perpendicular to the body axis of the X-ray fluoroscopic imaging table of the present invention and showing the relationship among the X-ray tube 1, the top plate 5 and the image receiving device 6. (A) shows a normal state in which the subject 4 is imaged at the center of the image receiving device 6, and (b) shows that the subject 5 is moved to the left from the center by the distance A, and the X-ray tube 1 (C) shows that the subject 5 is moved a distance A from the center to the right by a distance A, and the X-ray tube 1 is rotated to the right by a predetermined angle. FIG.
The X-ray fluoroscopic imaging table includes an X-ray tube 1 positioned in front of the subject 4 on the top plate and a flat panel image arranged opposite to the back side of the top plate 5 across the subject 4. The apparatus 6, rotation means for rotating the X-ray tube 1 so that the X-ray beam 3 moves in a direction perpendicular to the body axis direction of the subject 4, and the rotation angle information of the X-ray tube 1 are taken in. A top plate interlocking means for moving the top plate 5 to the left and right in conjunction with the movement of the beam 3 is constructed.
Although this embodiment requires a rotating means for rotating the X-ray tube 1, the support arm 7 that supports the X-ray tube 1 is moved parallel to the top plate 5, and the column 9 that holds the support arm 7. Since a complicated mechanism for rotating the lens is not required, the structure becomes simple.
[0017]
The rotating means for rotating the X-ray tube 1 is provided with a rotating mechanism at the tip of the support arm 7 of the X-ray fluoroscopic table, and can be rotated at an arbitrary angle by rotating an oblique switch provided on the control console. The tube 1 can be rotated. Information on the rotation speed and rotation angle is input to a CPU provided in the controller, and the CPU calculates the horizontal movement distance and the movement speed of the top 5 calculated from the oblique angle according to the information. 5 is moved to a predetermined position.
The top-plate interlocking means rotates the X-ray tube 1 to an arbitrary angle by rotating a tilt-in operation switch provided on the control console, and at the same time, the CPU calculates the top-plate from the tilt angle according to the information. The horizontal movement distance of 5 and its movement speed are calculated, and the top 5 is moved to a predetermined position.
[0018]
【The invention's effect】
The X-ray fluoroscopic imaging stand of the present invention is configured as described above, and uses a flat panel image receiving device as an overtube type device, and independently moves the left and right blades of the movable diaphragm in the direction perpendicular to the body axis. The top plate can be moved to the left and right in conjunction with the aperture, so that the X-ray beam is obliquely inserted into the subject from a direction perpendicular to the body axis direction of the subject and oblique fluoroscopic imaging is performed. It can be performed. For this reason, the structure of the apparatus is not greatly changed from the conventional one, and it is not necessary to make it complicated. In addition, it is possible to see the image by avoiding the overlap of the parts by enabling oblique insertion in the body side direction, and grasping the parts having structures in the depth direction such as blood vessels and bronchi in three dimensions Can do.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an X-ray fluoroscopic imaging table according to the present invention.
FIG. 2 is a diagram showing another embodiment of the X-ray fluoroscopic imaging table of the present invention.
FIG. 3 is a diagram showing a structure of an overtube type fluoroscopic imaging table.
FIG. 4 is a diagram showing a structure of a movable diaphragm for X-rays.
FIG. 5 is a diagram illustrating a structure of a flat panel image receiving apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... X-ray tube 2 ... Movable aperture 2a ... Blade 2b ... Blade 5 ... Top plate 6 ... Image receiving device 7 ... Support arm

Claims (1)

An overtube type X-ray fluoroscope having an X-ray tube provided in front of the subject on the top plate and a flat panel image receiving device arranged opposite to the back side of the top plate across the subject Blade driving means for independently operating the left and right blades in the movable diaphragm attached to the X-ray tube emission port so that the X-ray beam moves in the direction perpendicular to the body axis direction of the subject on the imaging table; An X-ray fluoroscopic imaging table, comprising: top plate interlocking means that takes in the operation information of the left and right blades and moves the top plate to the left and right in conjunction with the movement of the X-ray beam.

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