JP3331284B2 - Medical X-ray tomography system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to tomographic imaging of a subject, for example, so-called CT (Computed Tomography).
apy) and a medical X-ray tomography apparatus for performing panoramic imaging (curved tomography).

[0002]

2. Description of the Related Art The prior art of CT for obtaining a tomographic image of a cross section of a dental arch parallel to a transversal laminar plane of a patient as a subject, for example, a meshing plane, has a horizontal plane and a vertical plane area. An X-ray image detecting means called an X-ray detecting sensor array composed of an X-ray generator and a semiconductor, etc., supported by a turning support arm, is turned around the subject at a predetermined turning pitch, and is applied to the X-ray image detecting means. Multiple X of the subject
A line image is detected. At this time, the irradiated X-rays are in the form of a fan beam which spreads in a direction parallel to a turning plane generated by the X-ray generator, and the X-ray image detecting means detects each X-ray image. The image obtained by the X-ray image detecting means is calculated by a computer and output as a cross-sectional image.

[0003]

In the prior art of the above-mentioned head CT, when a large number of X-ray images are detected by the X-ray image detecting means, the patient is made horizontal, so that a very large installation area is required. In particular, CT for the cervical region has not yet been sold.

SUMMARY OF THE INVENTION An object of the present invention is to provide a medical X-ray imaging system capable of performing cross-sectional imaging and panoramic imaging with a small configuration having a small installation area.
It is to provide a line tomography apparatus.

[0005]

[0006]

According to the present invention, there is provided a support, an X-ray source and an X-ray image detecting means which are supported by the support, and which are disposed on both sides of the object with the object opposed to each other. Turning means for turning around the subject, wherein the X-ray source has an opening extending in the horizontal direction and the vertical direction on the front surface, or the opening is turned or turned in the horizontal direction and the vertical direction. A primary slit that generates a fan beam that spreads in a horizontal direction and a vertical direction whose shape can be changed, and an X-ray tube that generates X-rays in a horizontal direction and a vertical direction are provided inside, and the X-ray image detecting unit includes: An opening is extended in the horizontal and vertical directions for receiving X-rays from the X-ray source on the front surface, or a secondary slit capable of turning or changing the shape of the opening in the horizontal and vertical directions, Extend horizontally and vertically And a linear image detecting means, a panoramic X
In the case of X-ray photography, a primary slit having an opening extending in the vertical direction is selected, and the X-ray image detecting means is arranged in the vertical direction, and a secondary slit having the opening extending in the vertical direction on the front surface is selected. The slit can be selected, and in the case of cross-sectional photography of the subject,
A primary slit having an opening extending in the horizontal direction is selected, and the X-ray image detecting means is disposed in the horizontal direction, and a secondary slit having the opening extending in the horizontal direction on the front surface can be selected, and The X-ray image detecting means has a rotating means capable of changing the direction in the vertical direction and the horizontal direction according to the panoramic radiography and the cross-sectional radiography, and can perform both the panoramic radiography and the cross-sectional radiography. Medical X-ray tomography apparatus. According to the present invention, by changing the direction or shape of the primary slit, it is possible to switch between a horizontal slit-shaped X-ray beam and a vertical slit-shaped X-ray beam. The horizontal beam of the horizontal slit is used for cross-sectional imaging, and the vertical beam of the vertical slit is used for panoramic imaging.
In accordance with the switching between the horizontal beam and the vertical beam, the direction or shape of the secondary slit is switched, and
Light is received by the line image detecting means. Cross-sectional imaging for obtaining a tomographic image of a cross section of a cross section of a subject, for example, a dental arch parallel to an occlusal plane of the dental arch is performed as follows. First, the subject is positioned such that the position of the turning plane on which the X-ray source and the X-ray image detecting means are turned coincides with the cross section of the dental arch parallel to the occlusal plane. When the subject is set in this manner, the support is turned at a predetermined turning pitch by the turning means, and accordingly, the X-ray source and the X-ray image detecting means are turned in an opposed state with the subject interposed therebetween. Thus X
The subject is intermittently or continuously irradiated with X-rays from the source, and an X-ray image of the subject is detected by an X-ray image detecting means of, for example, a one-dimensional sensor or a two-dimensional sensor arranged in parallel with a turning plane. Is done. The X-ray image detecting means detects an X-ray image of the subject every time the support is turned by one turning pitch, converts the X-ray image into an electric signal, and temporarily stores it as image information in, for example, an image memory. In this way, when image information of a large number of X-ray images obtained by photographing the transverse layer surface of the subject from many directions is obtained, a CT (Computed Tomography) image is obtained using a computer or the like based on the large amount of image information. Can be played. Panoramic imaging of a subject, for example, curved tomography for obtaining a tomographic image of a curved tomographic surface of a dental arch along a direction in which the dental arch is arranged, is performed as follows. When the subject is placed between the X-ray source and the X-ray image detecting means, the X-ray source and the X-ray image detecting means are turned around the subject while X-rays from the X-ray source irradiate the subject. You. At this time, the X-ray source and the X-ray image detecting means rotate along the dental arch such that a straight line connecting the X-ray source and the X-ray image detecting means is substantially perpendicular to the dental arch. Is done. With the turning, the turning center position is adjusted by a position adjusting means such as an XY table or a known tomographic mechanism such that the imaging tomographic plane corresponds to the position of the dental arch. The X-rays that have passed through the subject in this manner enter X-ray image detecting means such as a one-dimensional sensor arranged perpendicular to the turning plane, are converted into electric signals, and temporarily stored as image information in, for example, an image memory. You. The X-ray images stored as image information in this manner are continuously stored in the order of detection,
From the continuously stored X-ray images, a plurality of X-ray images are selectively taken out at predetermined time intervals. Each X taken out
The line image is shifted by a predetermined amount in the direction in which the curved tomographic image to be obtained in the X-ray image moves and added, and as a result, image information corresponding to the tomographic image of the curved tomographic surface is formed. The constructed image information is output to a display unit or the like, and the display unit displays a tomographic image of the curved tomographic plane. Also, at the time of panoramic imaging, the image information detected by the X-ray image detecting means includes all information of the subject existing in the X-ray path, and the tomographic plane on which the curved tomographic image is formed is It is determined by the extraction interval when extracting a predetermined X-ray image from the continuously stored X-ray images and the shift amount of the extracted X-ray image, so that the detected image information is utilized. Image information of the target curved tomographic plane can be arbitrarily selected. In panoramic imaging, a known X-ray film may be used as an X-ray image detecting unit.
In this way, panoramic radiography can be performed in addition to cross-sectional radiography using the same device, so that the device can be widely used as a diagnostic device for dentistry or medical use. Further, it is possible to easily realize switching between the fan beam extending in the horizontal direction and the fan beam extending in the vertical direction of the X-ray, and it is possible to easily realize both the panoramic imaging and the cross-sectional imaging.

The present invention also provides a base, a support standing upright on the support, an elevating body capable of adjusting the vertical position with respect to the support, and an elevating body supported by the elevating body and sandwiching a subject. A support having a turning means for horizontally turning an X-ray source and an X-ray image detecting means disposed on both sides in opposition to each other around a subject; and a fixing means disposed on the support or the elevating body for positioning the subject. A medical X-ray tomography apparatus comprising: the X-ray source, wherein an opening is extended in a horizontal direction and a vertical direction on a front surface, or the opening is turned or shaped in a horizontal direction and a vertical direction. A primary slit that generates a fan beam that can be changed in the horizontal and vertical directions that can be changed, and an X-ray tube that generates X-rays therein are provided, and the X-ray image detecting means is provided on the front surface from the X-ray source. Horizontal and vertical receiving X-rays A secondary slit in which an opening is extended in the direction or the opening can be changed in direction and shape in the horizontal and vertical directions, and an X-ray image detecting means disposed inside, and a panorama In the case of X-ray imaging, a primary slit having an opening extending in the vertical direction is selected, and the X-ray image detecting means is arranged in the vertical direction, and the opening is extended in the front in the vertical direction. Next slit can be selected,
In the case of photographing a cross section of the subject, a primary slit having an opening extending in the horizontal direction is selected, and the X-ray image detecting means is arranged in the horizontal direction, and the opening is extended in the front in the horizontal direction. And the X-ray image detecting means has a rotating means capable of changing the direction in the vertical and horizontal directions according to the panoramic imaging and the cross-sectional imaging. This is a medical X-ray tomography apparatus characterized in that both imaging can be performed. According to the present invention, similarly to the above, by switching between the fan beam expanding in the horizontal direction and the fan beam expanding in the vertical direction of the X-ray, it is possible to selectively perform the cross-sectional imaging or the panoramic imaging in the same apparatus. In addition, since the support can be adjusted vertically, the turning surface can be adjusted to a desired height according to the physique of the subject. Furthermore, since the swing of the subject can be suppressed by the fixing means for positioning the subject, a high-quality X-ray tomographic image can be obtained.

[0008]

Further, according to the present invention, the X-ray image detecting means includes a stimulable phosphor sheet, an X-ray CCD sensor, a MOS sensor,
It is one of an X-ray fluorescence intensifier and a SIT (silicon intensifier). According to the present invention, an incident X-ray image can be detected with high sensitivity, high dynamic range, and high SN ratio.

Further, in the present invention, the X-ray image detecting means includes a stimulable phosphor sheet provided around a rotary drum, an excitation light source for irradiating the stimulable phosphor sheet with excitation light, A light receiving unit for receiving stimulated emission from the stimulable phosphor sheet, a rotation driving unit for rotating the rotating drum to perform main scanning, and moving the excitation light source and the light receiving unit along the axis of the rotating drum. And a linear drive unit for performing sub-scanning. According to the present invention, while irradiating a subject with X-rays, the stimulable phosphor sheet provided on the peripheral surface of the rotating drum is rotated at a low speed, so that a tomographic image along a predetermined tomographic plane can be stored. Recorded on the sheet. Thereafter, main scanning is performed by irradiating excitation light while rotating the rotating drum, and the emitted photostimulated light is received and converted into an image signal. Further, sub-scanning is performed by moving the excitation light source and the light receiving unit along the axial direction of the rotating drum. Thus, two-dimensional scanning of the entire surface of the sheet is enabled, and a tomographic image recorded on the stimulable phosphor sheet can be read. Further, since the stimulable phosphor sheet is formed in a cylindrical shape, the space required for moving the sheet can be small, and the apparatus can be downsized.

[0011]

Further, according to the present invention, the X-ray source may be a rotating means capable of changing the direction of the X-ray beam in the vertical and horizontal directions, or the X-ray source may be capable of irradiating the X-ray beam in the vertical and horizontal directions. It is characterized by having one of a bifocal X-ray tube. According to the present invention, switching between a horizontal beam and a vertical beam of X-rays can be easily realized, and both panoramic imaging and cross-sectional imaging can be easily realized.

[0013]

[0014]

FIG. 1 is a side view, partially cut away, of an X-ray tomography apparatus 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the internal configuration of the column 3. The X-ray tomography apparatus 1 generally includes a head holding device 2
, Support arm 5, elevating body 10, patient frame 40
5, a support 3, a base B, a chair 424, an image processing device 16 and a display device 17.

The head holding device 2 includes a pair of left and right temporal pressing members 432 corresponding to the both heads of the patient P, and an opening / closing mechanism 4 for moving the temporal pressing members 432 toward and away from each other.
33, the chin rest 434a, and the chin rest 434
a) (not shown). By rotating and displacing the dial 439, the base part of the temporal holding member 432 is moved toward and away from each other by the opening and closing mechanism 433, and the ear rod 438 is attached to its free end. . The temporal holding member 432 and the ear rod 438 are made of a material having high X-ray transmittance and rigidity, such as acrylic resin, fiber reinforced plastic using carbon fiber, or polycarbonate.

The support arm 5 is formed in a substantially U-shape. An X-ray generator and a primary slit plate are mounted in one end 5a, and a film is mounted on the other end 5b. The cassette 411 and the secondary slit plate 12 are mounted. Alternatively, instead of the film cassette 411, an X-ray sensor realized by a CCD or the like is incorporated.

The vicinity of the central portion 5c of the support arm 5 is
It is suspended from the holding frame 4 via the turning means 13, and the holding frame 4 is integrally extended from the elevating body 10. In the turning means 13, a turning mechanism 21 for turning the support arm 5 and a position adjusting mechanism 22 are incorporated. Therefore, the support arm 5 can be turned in accordance with the shape of the patient's dental arch, and curved tomography such as panoramic imaging can be performed.

The elevating body 10 is configured to be vertically displaceable on the column 3 as described later. This lifting body 10
, A patient frame 405 is attached so as to be vertically movable as described later. Furthermore, this patient frame 4
On the top of 05, realized with a flat panel switch etc.
An operation panel (not shown) for inputting shooting conditions is provided, and a display device (not shown) implemented by a liquid crystal display device or the like is provided adjacent to the operation panel for displaying the support screen for the input operation. Have been.

Further, a handle 429 is attached to the lower surface of the patient frame 405.
, The posture of the patient P at the time of imaging can be stabilized, and the shoulder of the patient P lowers,
The rotation of the support arm 5 is not hindered.

The column 3 is erected from a base B, and a swing member 423 is attached to the base B so as to be swingable by a rotation shaft 422. A chair 424 is attached to the swing member 423, and the patient P
The patient P is introduced into a predetermined imaging position by the swing displacement of the swing member 423, and thereby the patient P is smoothly introduced into the support arm 5 located near the patient's head without fear or oppression. Becomes possible.

As shown in FIG. 2, the lift 10 generally includes a frame 441, a housing 442, a pair of left and right guide wheels 443, a moving pulley 444, a motor 31a, and a constant load spring 446. It is configured. The frame body 441 is formed so as to surround the column 3, and has an upper end 44.
The holding frame 4 extends from 1a. On the inner peripheral surface of the frame body 441, both side surfaces 3c and 3d of the column 3
A guide wheel 443 slidable on both side surfaces 3c and 3d is attached to the surface facing the, so that the elevating body 10 can be displaced up and down on the column 3.

On the inner peripheral surface, the both side surfaces 3c,
A moving pulley 444 is provided so as to face 3d, and a wire 447 whose one end is fixed to the top 3a of the column 3 is wound around the moving pulley 444.
The other end is connected to the balance weight 449 via the moving pulley 444 via a fixed pulley 448 provided on the top 3a. The balance weight 449
Are guided in the column 3 so as to be vertically movable. The pulley 444 also meshes with a gear 450 mounted on the output shaft of the motor 31a,
The lifting and lowering body 10 can be vertically displaced by the rotational drive of 1a. When the desired lifting position is reached, the rotation of the fixed pulley 448 is prevented by the electromagnetic brake 451 provided in relation to the one fixed pulley 448, and thus the lifting body 10 is stably held at the predetermined position. Can be.

At the lower end 441b of the frame body 441, a pair of left and right guide shafts 452 are provided in parallel with the support columns 3, that is, in parallel with the elevating direction of the elevating body 10. Guide holes formed in a pair of guide pieces 405a of the patient frame 405 are fitted into the guide shaft 452, and the patient frame 405 is slidable on the elevating body 10 in this manner. The free end of the constant load spring 446 whose base end is attached to the frame 441 is connected to the upper end of the guide piece 405a. The number of the constant load springs 446 is selected according to the weight of the patient frame 405 to be suspended. Therefore, the operator can easily move the patient frame 405 up and down manually.

The guide piece 405a is provided with a frame body 44.
A positioning protrusion 405b is attached to face one side, and the elevating body 10 is vertically displaced so that the positioning protrusion 405b fits into the positioning recess 441c of the frame body 441 during panoramic photography. Further, a contact piece 405c is formed on one of the guide pieces 405a, and a pair of upper and lower limit switches 453 and 454 are provided on the frame body 441 corresponding to the contact piece 405c. The elevating body 10 can be displaced up and down with respect to the patient frame 405 within the range of the limit switches 453 and 454.

The guide piece 405a of the patient frame 405
Also, a stopper 455 is attached to the column 3 so as to face the column 3. A handle 456 is fixed to the stopper 455. The stopper 455 projects or retreats in accordance with the rotational displacement of the handle 456, and comes into frictional contact with the side surface 3d of the column 3 at the projecting position, thus forming the patient frame 405.
Is positioned and fixed.

FIG. 3 is a sectional view showing a schematic configuration of the position adjusting mechanism 22 and the turning mechanism 21 provided in the main body 19. FIG. 4 is a plan view of the position adjusting mechanism 22. The position adjusting mechanism 22 is provided with a pair of first guide rails 22a provided substantially along the direction approaching and separating from the columnar body 3 described above, and provided along a direction perpendicular to the first guide rails 22a. And a pair of second guide rails 22d. The second guide rail 22d is a movable carriage 22c guided along the first guide rail 22a.
, And the carriage 22c is provided with two pairs of rollers 22b.

The support arm 5 is supported by a shaft 23 guided along the second guide rail 22d. Shaft 2
3 is a carriage unit 2 provided with two pairs of rollers 22e.
2f, whereby the shaft 23 as the center of rotation of the support arm 5 can move in an arbitrary direction parallel to the horizontal direction.

A moving screw shaft 22h, which is rotationally driven by a pulse motor 22g, is screwed into the female screw body 22i provided on the moving carriage 22c. A moving screw shaft 22k, which is rotationally driven by a pulse motor 22j, is screwed into a female screw member 22m provided on the carriage portion 22f of the shaft member 23. Therefore, the pulse motors 22g and 22j
, And rotationally drive the moving screw shafts 22h and 22k to move the moving screw shafts 2 with respect to the female screw bodies 22i and 22m.
By screwing or unscrewing 2h and 22k,
The shaft body 23 is moved in any direction parallel to the horizontal direction.

The turning mechanism 21 generally includes the support arm 5
2 that pivotally supports the shaft via a bearing 21b
3 and a pulse motor 21d as a drive source for rotating the support arm 5. Pulse motor 2
A belt 21c is wound around an original vehicle 21f provided in 1d and a driven portion 21a provided at a lower end portion of the shaft body 23. The pulse motor 21d is fixed to the support arm 5 by a mounting member 21e.

When the pulse motor 21d is driven in the turning mechanism 21 configured as described above, the drive of the pulse motor 21d is transmitted to the shaft 23 via the belt 21c. When the power of the pulse motor 21 d is transmitted to the shaft 23, the pulse motor 21 d and the support arm 5 rotate integrally about the shaft 23 without rotating the shaft 23.

FIG. 5 is a sectional view showing a schematic structure of a lifting mechanism 31 provided in the columnar body 3 for vertically moving the lifting body 10. The lifting mechanism 31 includes a pulse motor 31a mounted on the columnar body 3, a lifting screw shaft 31b rotationally driven by the pulse motor 31a, and a female screw body 3 mounted on the lifting body 10 and screwed to the lifting screw shaft 31b.
1c.

In the lifting mechanism 31 configured as described above, when the pulse motor 31a is driven, the lifting screw shaft 31b driven by the pulse motor 31a advances or retreats to the female screw body 31c. 10 is moved up and down.

FIG. 6 is a diagram showing a schematic configuration of an automatic positioning mechanism 36 for adjusting the vertical position of the elevating body 10 provided in the elevating body 10. The automatic positioning mechanism 36 includes a rack 36c, a pointing light generating mechanism 36e fixed to the rack 36c, a variable resistor 36d for detecting the vertical position of the rack 36c and the pointing light generating mechanism 36e, and an automatic positioning mechanism. It comprises a sensor 37 and a pulse motor 36a for vertically moving the rack 36c. Pulse motor 36a
Is mounted with a pinion 36b that meshes with the rack 36c.

The indicating light generating mechanism 36e includes a light source, a lens,
The pointing light, which is a light emitted from the pointing light generating mechanism 36e, has a shape elongated in the horizontal direction. Referring to FIG. 1, the indicating light emitted from the indicating light generating mechanism 36e is applied to the face of a patient, which is a subject, through a light transmitting part 10a provided in front of the elevating body 10. In this manner, the pulse motor 36a is controlled via the operation command input unit 11 or the like so that the emitted instruction light matches the position of the transverse layer surface of the patient to be imaged or the center position of the curved tomographic surface, A vertical position with respect to the patient's face is set.

As described above, when the rack 36c and the indicator light generating mechanism 36e are vertically displaced, the resistance value of the variable resistor 36d changes with the displacement of the rack 36c, and the rack 36c, that is, the above-described indicator light The position in the vertical direction is detected by the automatic positioning mechanism sensor 37 as a voltage value corresponding to the resistance value of the variable resistor 36d.

The above-described pulse motor 31a of the lifting mechanism 31
Is controlled by a control system described later based on the voltage value detected by the sensor 37 for the automatic positioning mechanism, and the turning plane on which the X-ray generator 7 and the X-ray image detecting means 6 are turned is indicated by the indicating light. The vertical position is set so as to coincide with the center of the cross-sectional surface or curved tomographic surface of the patient to be imaged. It is needless to say that the positioning in the vertical direction is not limited to this, and may be performed by manual positioning like a well-known dental panoramic X-ray apparatus.

FIG. 7 is a perspective view showing the structure of the X-ray generator 7 built in the support arm 5 and the rotation mechanism 41 for the X-ray generator, which is an irradiation field shape switching means. A shaft 41a to which a gear 41b is fixed is connected to the X-ray generator 7, and the gear 41b drives a pulse motor 41c equipped with a gear 41d, so that the X-ray generator 7 It is rotated about an axis parallel to the irradiation direction.

The X-ray generator 7 emits X-rays through a slit 7a for limiting the irradiation field of the X-rays to be emitted.
At this time, the irradiation field shape of the X-ray emitted from the X-ray generator 7 is elongated in one direction,
By driving c, the irradiation field shape of the X-ray is switched between a direction parallel to the aforementioned turning plane and a direction perpendicular thereto.

FIG. 8 is a perspective view showing a partial configuration of the X-ray image detecting means 6 provided on the support arm 5. The X-ray image detecting means 6 includes two linear sensors 46 and 47 and a plate substrate 48 on which the linear sensors 46 and 47 are installed. The line-shaped sensor 47 is used for detecting an X-ray image at the time of cross-layer imaging described later, and is arranged so as to be parallel to the horizontal direction, that is, parallel to the above-described turning plane. The line sensor 46 is used for detecting an X-ray image at the time of curved tomography described later, and is arranged so as to be perpendicular to the horizontal direction, that is, perpendicular to the above-described turning plane. The operation of detecting an X-ray image by the line sensors 46 and 47 will be described later with reference to FIG.

FIG. 9 shows a control circuit 6 provided in the main body 19.
FIG. 2 is a block diagram showing an electrical configuration of FIG. Control circuit 61
The control unit 52 includes a CPU (Central Processing Unit) and the like, and the pulse motors 41c, 31a, 36
a, 22g, 22j, and 21d, respectively, and motor driving circuits 53 to 57, and motors 327 and 36 to be described later.
0a to 363a, 364;
It comprises various sensors 37, 58 to 60, an X-ray generation circuit 51 for generating X-rays, and an operation command input unit 11.

When the operator operates the operation command input unit 11 to input a command for instructing the imaging mode, a predetermined signal is output from the control unit 52 in accordance with one of the transverse layer imaging and the curved tomography. It is output to each of the drive circuits 53-57. As a result, each motor is driven, and the result is
7, 58 to 60, and are fed back to the control unit 52. As will be described later, the number of motors varies depending on the driving mode, and the driving circuits and sensors are provided accordingly.

FIG. 10 is a block diagram showing the electrical configuration of the image information processing circuit 66 provided in the X-ray tomography apparatus 1. When the X-ray 74 that has passed through the patient enters the X-ray image detecting means 6, the X-ray 74 enters the scintillator 50 provided in front of the linear sensors 46 and 47, that is, in the direction toward the X-ray generator 7. When the X-rays 74 are incident on the scintillator 50, the X-rays 74 are converted into visible light, and the converted visible light is converted into a FOP (fiber optical plate).
, And enters the linear sensors 46 and 47 realized by a CCD (charge coupled device) or the like. At this time, the X-rays that have passed through the scintillator 50 without being converted into visible light are shielded by the FOP 49 formed of an X-ray shielding material such as lead glass, and the X-rays enter the linear sensors 46 and 47. The linear sensor 4
6, 47 is prevented from being damaged. In addition, at the time of curved tomography of panoramic photography, TDI (Time Delay)
Integration) Drive.

Thus, the line sensors 46, 4
The X-ray image of the patient that has reached 7
7 and is converted into an electric read signal as image information. At this time, the read signals output from the linear sensors 46 and 47 are output to the amplification circuit 68 based on the synchronization signal output from the synchronization signal output circuit 67. The read signal output in this manner is amplified by the amplifier circuit 68, and the analog / digital conversion circuit 6
After being converted from an analog signal into a digital signal by 9, it is temporarily stored in the main memory 70.

Based on the image information temporarily stored in the main memory 70, the CPU 71 performs arithmetic processing corresponding to cross-sectional imaging or curved tomography, and constructs tomographic image information corresponding to the cross-layer or curved tomography. The tomographic image information configured by the CPU 71 is output to the display memory 73 via the main memory 70. The tomographic image information is recorded by a recording device 72 including a hard disk, a floppy disk, and the like. The tomographic image information output to the display memory 73 is displayed on the display unit 17a of the display device 17.
Is displayed as a tomographic image. Further, the tomographic image obtained in this manner may be printed by a printing unit.

Cross-sectional imaging by the X-ray tomography apparatus 1 configured as described above is performed as follows. With the patient standing in front of the device body 19, the automatic positioning mechanism 36
Is emitted from the indicating light generating mechanism 36e, and the pulse motor 36a of the automatic positioning mechanism 36 is driven to move the indicating light to the position of the cross-sectional surface of the patient to be imaged. When the pointing light is moved to the position of the transverse layer to be photographed, the vertical position of the pointing light generating mechanism 36e is detected by the sensor 37 for the automatic positioning mechanism. The pulse motor 31a of the lifting mechanism 31 is driven based on the detected position,
The vertical position is set such that the turning plane on which the X-ray generator 7 and the X-ray image detecting means 6 are turned coincides with the cross-layer surface indicated by the indicating light. If the indicator light generating mechanism is attached to the cross-layer surface position of the apparatus from the beginning, the cross-layer surface at the position indicated by the indicator light can be photographed.

When the vertical position of the turning plane is set, the patient's head is fixed to the chin fixing part 8a of the chin fixing body 8, the forehead fixing member 9b of the head fixing mechanism 9, and a pair of temporal fixing parts. It is fixed by the member 9c, and photographing is started.

In the transverse layer radiography, the X-ray generator 7 continuously or intermittently irradiates the X-rays.
The X-ray image detecting means 6 is turned at a predetermined turning pitch in an opposed state with the patient's head interposed therebetween. At this time, the X-ray generator 7 and the X-ray image detecting means 6 adjust the rotation center position of the X-ray generator 7 and the X-ray image detecting means 6 to the X-ray generator 7 and the X-ray image Detecting means 6
Is adjusted so as to penetrate the dental arch along the mesio-distal direction. Alternatively, a method of fixing the rotation center at one point may be used.

With the rotation of the X-ray generator 7 and the X-ray image detecting means 6, the X-ray generator 7 and the X-ray image detecting means 6
Each time the vehicle is turned by the turning pitch, the linear sensor 47
Detects an X-ray that has passed through a patient's dental arch, and converts an X-ray image of the dental arch included in the X-ray into an electronic read signal as image information. The image information converted into the read signal is
It is temporarily stored in the main memory 70.

As described above, imaging is performed while rotating the X-ray generator 7 and the X-ray image detecting means 6 around the patient, so that a large number of image information obtained by imaging the transverse layer surface of the dental arch from many directions. Is obtained. This lot of image information is
A CPU stored in the main memory 70 and provided in the image information processing apparatus 16 based on the large amount of image information
Reference numeral 71 performs arithmetic processing corresponding to cross-layer imaging, thereby forming tomographic image information corresponding to a tomographic image of the cross-layer surface of the dental arch. The configured tomographic image information is output to the display device 17, and the tomographic image of the transverse layer is displayed on the display unit 17a of the display device 17.

The curved tomography of the panoramic imaging by the X-ray tomography apparatus 1 is performed as follows. As in the case of the above-described cross-sectional imaging, the patient stands in front of the apparatus main body 19, emits the indicating light from the indicating light generating mechanism 36e of the automatic positioning mechanism 36, drives the pulse motor 36a, and outputs the indicating light to the patient. To the position of the curved tomographic plane to be photographed.
At this time, the position of the pointing light is set such that the vertical position is located at the center of the curved tomographic plane to be imaged by the patient in the vertical direction. When the position of the pointing light is set, the pulse motor 31a of the elevating mechanism 31 is driven based on the position, and the vertical position of the turning plane on which the X-ray generator 7 and the X-ray image detecting means 6 are turned is The setting is made so as to coincide with the position of the curved tomographic plane specified by the pointing light.

When the vertical position of the turning plane is set, the patient's head is fixed by the chin fixing body 8 and the head fixing mechanism 9, and the photographing is started.

In the curved tomography, the X-ray generator 7
The X-ray generator 7 and the X-ray image detecting means 6 are rotated around the patient while the lines are continuously irradiated. At this time, the X-ray generator 7 and the X-ray image detecting means 6 are arranged such that the straight line connecting the X-ray generator 7 and the X-ray image detecting means 6 is substantially orthogonal to the dental arch along the patient's dental arch. It is turned as follows.
Along with the turning, the turning center position is adjusted by the position adjusting mechanism 22.

As the X-ray generator 7 and the X-ray image detecting means 6 rotate, the linear sensor 46 provided in the X-ray image detecting means 6 continuously detects the X-rays passing through the patient's dental arch. The X-ray is detected and the X-ray image of the dental arch of the X-ray is converted into an electric read signal as image information. The converted image information is temporarily stored in the main memory 70.

At the time of curved tomography, an amplification circuit 68 and an analog / digital conversion circuit 69 are supplied from the linear sensor 46.
For example, the same signal format as the video signal of the television is adopted as the signal format of the read signal output to the main memory 70 through the
The line images are continuously stored in the main memory 70 at a rate of 30 sheets per second. This X-ray image is obtained by the linear sensor 46.
Is a vertically elongated slit image corresponding to the shape of the patient.
A series of zero X-ray images is stored.

As described above, when the photographing is performed from one side to the other side of the patient's dental arch, arithmetic processing by the CPU 71 is performed based on the image information stored in the main memory 70. First, the CPU 71 determines an extraction interval for selectively extracting X-ray images arranged at a predetermined time interval from a series of X-ray images continuously stored in the main memory 70, and calculates each of the extracted X-ray images. A distance to be added while shifting the position by a predetermined distance in the width direction of the slit image, that is, a shift amount is selected.

Next, at the selected take-out interval, the corresponding X
Line images are sequentially taken out in the form of digital signals, and an addition process is performed while shifting the position according to the selected shift amount. At this time, the extraction interval and the shift amount can be arbitrarily selected, and correspondingly, a tomographic image of a specific curved tomographic plane is obtained by the above-described addition processing. The tomographic image of the curved tomographic plane thus obtained is displayed on the display unit 17a of the display unit 17.
Displayed by

Therefore, the X-ray image detecting means 6 provided with the line sensor 47 can be downsized during cross-sectional imaging.

The X-ray tomography apparatus 1 has a wide range of use and is effective for dental diagnosis and medical diagnosis.
Can be realized.

Further, the X-ray image of the patient is
6 and 47, the work of developing the X-ray film is not required as compared with, for example, the case where the X-ray image is detected by the X-ray film, so that the working process of the development can be simplified.

Further, the image information converted into the electric read signal by the line sensors 46 and 47 can be immediately processed, and the time required for obtaining the tomographic images of the transverse layer surface and the curved tomographic surface can be greatly reduced. Can be shortened.

At the time of curved tomography, the image information detected by the line sensor 46 includes all information of the patient present on the X-ray path, and a curved tomogram is formed. The tomographic plane has an extraction interval when a predetermined X-ray image is selectively extracted from the X-ray images stored in the main memory 70, and a shift amount when the extracted X-ray image is shifted. Thus, the target curved tomographic plane can be arbitrarily selected by utilizing the detected image information.

Further, in the X-ray tomography apparatus 1, the positions of the turning planes of the X-ray generator 7 and the X-ray image detecting means 6 are automatically positioned at the positions of the transverse layer plane or the curved tomographic plane to be photographed by the patient. Since the operator only needs to move the pointing light emitted from the pointing light generating mechanism 36e to the position of the patient's cross-sectional surface or curved tomographic surface to be imaged, the operator turns The operability of the setting operation of the position in the vertical direction of the plane can be improved.

The irradiation field shape of the X-ray emitted from the X-ray generator 7 is such that the X-ray generator 7 is rotated by the X-ray generator rotation mechanism 4.
By rotating in step 1, it can be switched in accordance with the type of radiography, so that it is possible to prevent X-rays from being radiated to a part unrelated to radiography of the patient, thereby minimizing the radiation dose to the patient. can do.

FIG. 11 is a perspective view showing a partial configuration of an X-ray image detecting means 106 provided in an X-ray tomography apparatus according to another embodiment of the present invention. Here, the X-ray image detecting means 106 is connected to the drum 76 on which the stimulable phosphor sheet is mounted.
It is comprised including. Except that the X-ray image detecting means 106 is provided instead of the X-ray image detecting means 6,
The X-ray tomography apparatus has the same configuration as the X-ray tomography apparatus 1 shown in FIGS.

The X-ray image detecting means 106 includes a drum 76,
It comprises a pair of support members 78 and 79 that support the drum 76 and a pulse motor 80 that drives the drum 76 to rotate. The drum 76 has an arc-shaped outer peripheral surface 7 that is outwardly convex.
6d and a pair of fan-shaped end walls 76b provided at both ends of the peripheral wall 76a.
The stimulable phosphor sheet (not shown) is mounted along the outer peripheral surface 76d of the drum 76. In two pairs of end walls 76b,
Each of the shafts 77 is attached,
Is supported by a pair of support members 78 and 79. One end of the outer peripheral surface 76d of the peripheral wall 76a has an outer peripheral surface 76d.
A belt-like rubber sheet 76c is stuck along the circumferential direction of. A pulse motor 80 is attached to the rubber sheet 76c.
, The pinch roller 80a mounted on the contact member is brought into contact with the pinch roller 80a.

The X-ray image detecting means 10 constructed as described above
6 is built in the end 5b of the support arm 5 so that the rotation axis of the drum 76 is parallel to the turning plane and the outer peripheral surface 76d of the drum 76 faces the X-ray generator 7. On the X-ray generator 7 side of the X-ray image detecting means 106 thus incorporated, a slit is provided for setting the light receiving shape of X-rays received by the storage phosphor sheet mounted on the outer peripheral surface 76d. A light receiving shape setting plate is provided.
The slit of the light receiving shape setting plate has an elongated shape in a direction parallel to the turning plane.

Cross-sectional imaging by an X-ray tomography apparatus provided with the X-ray image detecting means 106 is performed as follows. As described above, while the X-ray generator 7 continuously or intermittently irradiates X-rays, the X-ray generators 7 and X
When the line image detecting means 106 is turned at a predetermined turning pitch, the pulse motor 80 of the X-ray image detecting means 106 is driven at a predetermined pitch in conjunction therewith, and the stimulable phosphor sheet of the drum 76 is mounted. The outer peripheral surface 76d is rotated at a predetermined rotation pitch, for example, in the direction of arrow A with respect to the slit of the light receiving shape setting plate (not shown). The rotation of the drum 76 by the pulse motor 80 is performed every time the X-ray generator 7 and the X-ray image detecting means 106 are turned by one turn pitch, and accordingly, the light receiving shape setting plate (not shown) A slit-shaped X-ray image of the subject passing through the slit is sequentially recorded on the stimulable phosphor sheet along the circumferential direction of the outer peripheral surface 76d.

The X-ray image recorded on the stimulable phosphor sheet is read by a reading device or the like that reads out stimulating light by irradiating excitation light (not shown) and is converted into an electrical reading signal as image information. Many Xs converted to electrical read signals
By performing arithmetic processing based on the line image in the same manner as described above, it is possible to form a tomographic image of the transverse layer taken of the patient.

Accordingly, since the stimulable phosphor sheet is mounted on the outer peripheral surface 76d of the drum 76, the X-ray recording medium mounted on the conventional flat plate is displaced in a direction perpendicular to the turning plane. In comparison, the area in which the stimulable phosphor sheet is moved can be made smaller, and as a result, the device can be made smaller than in the past. In addition, since the stimulable phosphor sheet is mounted on a drum whose axis of rotation is parallel to the rotation plane, the drum, the drum, and the casing that stores the stimulable phosphor sheet collide with the patient's shoulder during imaging. Can be prevented.

FIG. 12 is a perspective view showing a partial configuration of an X-ray image detecting means 206 provided in an X-ray tomography apparatus according to another embodiment of the present invention. Here, an X-ray image detecting device configured so that a single linear sensor 82 in which a CCD sensor or the like is connected in a line is switched between a state parallel to the aforementioned turning plane and a state perpendicular thereto. Means 206
Is provided. The other parts are the same as those of the X-ray tomography apparatus 1 shown in FIGS. 1 to 10 except that an X-ray image detection unit 206 is provided instead of the X-ray image detection unit 6 described above. Configuration.

The X-ray image detecting means 206 includes a single linear sensor 82, a plate substrate 81 on which the linear sensor 82 is installed, and a pulse motor 83 for driving the plate substrate 81 to rotate. . Plate substrate 81
Has a disk-like shape, and its outer peripheral surface is a pulse motor 83.
The gear portion 81a meshes with the gear 83a mounted on the gear. When the pulse motor 83 is driven, the plate substrate 81 is rotated, for example, in the direction of arrow B, and the arrangement direction of the linear sensors 82 is changed accordingly.

The direction in which the linear sensors 82 are arranged is such that the X-ray generator 7 and the X-ray image
6 is set in a direction parallel to the turning plane to be turned, and in the case of curved tomography, the direction is set to a direction perpendicular to the turning plane.

Therefore, by switching the arrangement direction of the single line sensor 82, the single line sensor 82 is used for both cross-section imaging and curved tomography imaging. The apparatus cost can be reduced as compared with the case of using. In addition,
As the X-ray image detecting means, in addition to the CCD sensor, a MOS sensor, a stimulable phosphor sheet, or the like can be used.

FIG. 13 is a perspective view showing the configuration of an X-ray generator 107 and an irradiation field shape switching mechanism 141 as irradiation field shape switching means provided in an X-ray tomography apparatus according to another embodiment of the present invention. is there. Here, the irradiation field shape of the X-rays irradiated from the X-ray generator 107 is an irradiation provided with the irradiation field shape switching plate 86 provided with a plurality of openings 86a, 86b, 86c for setting the irradiation shape. Field shape switching mechanism 141
Is switched by The X-ray generator 10 and the X-ray generator rotation mechanism 41 are replaced with the X-ray generator 10.
7 and the other parts except that the irradiation field shape switching mechanism 141 is provided have the same configuration as the X-ray tomography apparatus 1 shown in FIGS. 1 to 10 described above.

The irradiation field shape switching mechanism 141 includes an irradiation field shape switching plate 86, a screw shaft 88, and a pulse motor 87 for driving the screw shaft 88 to rotate. The switching plate main body 86e, which is a plate-like member having a longitudinal shape, has, in order from one side, an opening 86a for cross-sectional imaging, an opening 86b for curved tomography, and an opening 86 for planar tomography.
c are provided in one row. Opening 86a for cross-section imaging
Has an elongated shape in a direction parallel to the turning plane,
The opening 86b for curved tomography is elongated in a direction perpendicular to the turning plane, and the opening 8b for plane tomography is formed.
6c has a substantially square shape.

A screw shaft 88 is screwed into a pair of female screw bodies 86d provided at the lower ends at both ends of the switching plate body 86e. By driving the pulse motor 87, the irradiation field shape switching plate 86 is It is moved to one side or the other side along the longitudinal direction of the switching plate main body 86e. In this manner, by moving the irradiation field shape switching plate 86,
One of the plurality of openings 86a, 86b, 86c is installed at a position facing the X-ray irradiation head 107a for irradiating the X-ray of the X-ray generator 107.

FIG. 14 is a perspective view showing a partial configuration of an irradiation field shape switching mechanism 241 provided in an X-ray tomography apparatus according to another embodiment of the present invention. Here, a plurality of openings 91a, 91b, 91c for setting the irradiation shape are X-ray-irradiated by an irradiation field shape switching mechanism 241 having a disk-shaped irradiation field shape switching plate 91 provided along the circumferential direction. Are switched. The other parts except that the irradiation field shape switching mechanism 241 is provided instead of the irradiation field shape switching mechanism 141 described above are the same as those shown in FIG.
The configuration is the same as that of the X-ray tomography apparatus including the ray generator 107 and the irradiation field shape switching mechanism 141.

The irradiation field shape switching mechanism 241 includes an irradiation field shape switching plate 91 and a pulse motor 92. The irradiation field shape switching plate 91 having a disc shape has a plurality of openings 91 a along the circumferential direction of the irradiation field shape switching plate 91.
91b and 91c are provided. A shaft hole 91e is provided at the center of the irradiation field shape switching plate 91, and an outer peripheral surface of the irradiation field shape switching plate 91 is a gear portion 91d that meshes with a gear 92a mounted on the pulse motor 92. . When the pulse motor 92 is driven, the irradiation field shape switching plate 91 is rotated to one side or the other side around the shaft hole 91e,
One of the plurality of openings 91a, 91b, and 91c is provided with the X-ray irradiation head 107 of the X-ray generator 107.
It is set at a position facing a.

As described above, each of the openings 91a, 91b, 9
When 1c is set at a position opposed to the X-ray irradiation head 107a, the opening 91a for cross-sectional imaging becomes elongated in a direction parallel to the above-described turning plane, and the opening 91b for curved tomography becomes It becomes elongated in the direction perpendicular to the turning plane, and has a rectangular opening 91 for planar tomography.
c indicates that two of the four inner peripheral surfaces defining the opening 91c are parallel to the turning plane.

FIG. 15 is a perspective view showing the configuration of an irradiation field shape setting mechanism 102 provided in an X-ray tomography apparatus according to another embodiment of the present invention. Here, the width of the slit-shaped irradiation field shape of the X-ray emitted from the X-ray generator, that is, the width in the direction perpendicular to the longitudinal direction of the irradiation field shape is changed by the irradiation field shape setting mechanism 102. .

The irradiation field shape setting mechanism 102 includes a pair of swing members 96, two pairs of support members 97 and 98 for swingably supporting the respective swing members 96, a screw shaft 100, and a screw shaft 10.
0 is provided. Each of the rocking members 96 having a flat and quadrangular shape is attached to each of the supporting members 97 and 9 at the upper and lower end surfaces in FIG.
8, two pairs of bolts 99a, 99b are screwed through elongated support holes 97a, 98a in one direction, and are supported swingably.

Each of the rocking members 96 thus supported is provided with a female screw member 96a at a free end which is rocked and displaced about a portion screwed by bolts 99a and 99b. Each of the female screw bodies 96a is
6 is pivotally supported by a swing member 96 so as to be angularly displaceable about an axis parallel to the axis when the swing displacement is performed.

The screw shaft 100 screwed into each female screw body 96a
The thread groove of the portion screwed to one female screw member 96a and the screw shaft of the portion screwed to the other female screw member 96a are opposite to each other. Therefore, when the pulse motor 101 is driven, each free end of each swing member 96 moves in a direction away from each other as shown by arrows E1 and F1, or in a direction close to each other as shown by arrows E2 and F2. As a result, the interval between the distal end portions 96b on the free end side of the surfaces of the rocking members 96 facing each other is changed.

The X-ray generator is provided with two X-ray tubes: an X-ray tube for cross-sectional imaging and an X-ray tube for curved tomography. The above-mentioned irradiation field shape setting mechanism 102 is provided one by one corresponding to each X-ray tube, and the X-rays generated by each X-ray tube emit a pair of swing members in the corresponding irradiation field shape setting mechanism 102. Irradiation is performed through the space between the tips 96 b of the 96.

At this time, the irradiation field shape setting mechanism 102 for photographing the cross-section layer X is irradiated through the space between the distal ends 96b.
The irradiation field shape of the line is elongated in the direction parallel to the above-mentioned swivel plane, that is, the direction in which the swing member 96 approaches or separates from the swivel plane is a vertical direction perpendicular to the swivel plane. Be prepared for. In addition, the irradiation field shape setting mechanism 102 for curved tomography is configured so that the irradiation shape of the X-ray irradiated through the space between the distal end portions 96b is elongated in a direction perpendicular to the turning plane, that is, Swing member 96
Is provided so that the direction in which they are moved toward or away from each other is a horizontal direction parallel to the turning plane.

Therefore, since the width of the X-ray irradiation field shape can be changed, X-rays can be irradiated with an appropriate width, and as a result, the exposure dose to the patient can be minimized.

FIG. 16 is a perspective view showing a configuration of an irradiation field shape setting mechanism 202 provided in an X-ray tomography apparatus according to another embodiment of the present invention. 16, the same reference numerals are given to portions corresponding to and similar to the irradiation field shape setting mechanism 102 in FIG. Here, the distance between the opposing surfaces 106b of the moving members 106 through which the X-rays emitted from the X-ray generator pass is changed by the linear movement of the pair of moving members 106 in the direction of approaching or moving away from each other. are doing. The irradiation field shape setting mechanism 10 described above is used.
Except that the irradiation field shape setting mechanism 202 is used instead of 2, the other parts have the same configuration as that of the X-ray tomography apparatus provided with the irradiation field shape setting mechanism 102 shown in FIG.

The irradiation field shape setting mechanism 202 includes a pair of moving members 106, a screw shaft 100, and a pulse motor 101. Each moving member 106 has a substantially L-shaped cross-sectional shape, and has a structure in which two flat plate-like members are connected to each other in a direction perpendicular to each other. Each of the moving members 106 has a female screw portion 106a to which the screw shaft 100 is screwed. When the pulse motor 101 is driven, each moving member 106
The moving members 106 are moved in directions away from each other as indicated by arrows G1 and H1 or in directions approaching each other as indicated by arrows G2 and H2, whereby the distance between the opposing surfaces 106b of each moving member 106 is changed. X-rays emitted from an X-ray generator (not shown) are applied through the surfaces 106b of the moving members 106 facing each other.

FIG. 17 shows an X-ray tube 11 provided in an X-ray generator of an X-ray tomography apparatus according to another embodiment of the present invention.
FIG. 2 is a perspective view schematically showing a partial configuration of a zero. Here, the X-ray generator is provided with a multifocal X-ray tube 110.

The X-ray tube 110 is generally a cathode 2
It comprises two filaments 111 and 112 and a target 113 which is an anode. Target 113
Are two anode surfaces 113a, on which electron beams 114, 115 emitted from the filaments 111, 112 are focused.
113b. Two anode surfaces 113a, 113b
Are perpendicular to each other, for example, the anode surface 1
X-rays emitted from 13a are used for cross-sectional radiography,
X-rays emitted from the anode surface 113b are used for curved tomography.

Generally, X-rays emitted from an X-ray tube include:
Although there is directivity depending on the direction of the target and the shape and direction of the filament with respect to the target, a composite focus type X-ray including two filaments 111 and 112 and a target 113 having two anode surfaces 113a and 113b is provided. By using the tube 110, X-rays suitable for transverse layer imaging and curved tomography can be generated.

FIG. 18 is an overall configuration diagram showing still another embodiment of the present invention. An X-ray generator 301 and an X-ray imager 310 are installed at both ends of the turning arm 302 so as to face each other. The X-ray generator 301 is an X-ray tube 353
And a primary slit 351 and the like, and emits a slit-shaped X-ray beam toward the subject P. The X-ray imager 310 is
The secondary slit 352 receives the X-ray image passing through the subject P.
An X-ray image is recorded on the cylindrical stimulable phosphor sheet 311 via the. The stimulable phosphor sheet 311 has, for example, a circumference of 300 to correspond to the current X-ray panoramic film.
mm and a width of 150 mm.
It is provided on the peripheral surface of a rotating drum arranged in parallel with the turning axis of the rotating drum, and rotates at a low speed at the time of X-ray imaging and rotates at a high speed at the time of reading an image.

The swivel arm 302 is supported by a fixed arm 305 via a rotary table 303 and an XY table 304. The swivel position of the swivel arm 302 is such that a tomographic image of the subject P along a predetermined tomographic plane is captured. , The turning speed and the turning center are controlled.

The X-ray generator 301 is attached to the turning arm 302 via a rotation mechanism 360, and is rotatable around an irradiation center axis connecting the X-ray generation unit and the X-ray detection unit. In FIG. 18, the X-ray generator 301 is held in a vertical position, the primary slit 351 is positioned in the vertical direction, generates a vertical slit-shaped X-ray beam, and is arranged for panoramic imaging. On the other hand, X
When the line generator 301 is held in a horizontal posture, the primary slit 351 is positioned in the horizontal direction, generates a horizontal slit-shaped X-ray beam, and is arranged for cross-sectional imaging. Further, the X-ray tube 353 is also attached to the X-ray generator 301 via the rotation mechanism 361, and is rotatable around an axis parallel to the turning axis of the turning arm 302, so that the direction of X-ray beam generation can be adjusted. I have to.

The X-ray imaging device 310 is also attached to the turning arm 302 via the rotating mechanism 362, similarly to the X-ray generator 301, and has an irradiation center axis connecting the X-ray generation unit and the X-ray detection unit. It becomes rotatable around. In FIG. 18, the X-ray imaging device 310 is held in a vertical position, the secondary slit 352 is positioned in the vertical direction,
Receiving the line beam, it is arranged for panoramic photography. On the other hand, when the X-ray imaging device 310 is held in a horizontal position by the rotation mechanism 362, the secondary slit 352 is positioned in the horizontal direction, receives the horizontal slit-shaped X-ray beam, and changes the arrangement for transverse layer imaging. Take.

The rotation mechanisms 360 to 362 and a rotation mechanism 363 described below are examples including motors 360a to 363a, worm gears, and the like. However, the present invention is not limited to this, and well-known rotation mechanisms can be employed.

FIG. 19 is a block diagram showing the X-ray image pickup device 310 of FIG. In the X-ray imager 310, the stimulable phosphor sheet 311 is provided on the peripheral surface of the rotating drum 312, and the shaft 313 of the rotating drum 312 is driven to rotate by the rotating mechanism 363. A detection member 317 for defining the rotation start position of the drum is provided at the end of the peripheral surface of the rotating drum 312, and the light emitting diode 318 and the photo interrupter 319 generate a pulse signal corresponding to the home position of the rotating drum 312 at which imaging starts. .

A laser 321 such as a semiconductor laser is used as an excitation light source for irradiating the stimulable phosphor sheet 311 with excitation light. The excitation light emitted from the laser 321 is focused by a lens or the like, and is obliquely incident on the stimulable phosphor sheet 311 at approximately 45 °. From the portion irradiated with the excitation light, stimulated emission is generated according to the X-ray energy stored in the stimulable phosphor sheet 311. The photostimulated light is received by a photomultiplier (photomultiplier tube) 325 installed close to the stimulable phosphor sheet 311. The light receiving surface of the photomultiplier 325 is provided with an optical filter that blocks excitation light and passes only stimulated emission.

The laser 321 and the photomultiplier 325 are integrally mounted on the screw shaft 326, move linearly at a constant speed along the axial direction of the rotating drum 312 by the rotation of the motor 327, and perform sub-scanning during reading. . On the other hand, main scanning at the time of reading is performed by rotation of a rotary drum 312 driven by a high-speed rotation motor 363a incorporated in the rotation mechanism 363. When the two-dimensional scanning of the stimulable phosphor sheet 311 is completed, the erasing lamp 320 is turned on with the rotation of the rotating drum 312, and the remaining X-ray energy is entirely erased.

The pulse signal from the photo sensor is supplied to a motor driver 328 for driving a motor 327, and is used for synchronizing the rotating drum 312 and the screw shaft 326, a CTC (counter timer circuit) 340, and a CPU.
The signal is also supplied to an integration circuit 343 via a (central processing unit) 341 and a CTC (counter timer circuit) 342.

The image signal converted into an electric signal by the photomultiplier 325 is input to the integration circuit 343, where the integration is performed in synchronization with the above-mentioned pulse signal, and thereafter, the S / H (sampling and hold) circuit 344 performs the integration. The data is sampled, converted to a digital value by an A / D (analog-to-digital conversion) circuit 345, and stored in a frame memory 346. The image data stored in the frame memory 346 is C
The image is displayed on a display device 347 such as an RT (cathode ray tube).

Since the output from the photomultiplier 325 matches the acoustic frequency, the signal is not immediately processed and is recorded separately on an MD (mini-disc) recording device or a DAT (digital audio tape) recording device. But it doesn't matter.

Next, the recording operation will be described. First, at the time of X-ray imaging, the operations of the laser 321, the photomultiplier 325, the erase lamp 320, and the like are stopped, and the rotating drum 312 is moved by the low-speed rotation motor 364 with a built-in clutch into the movement of the swing arm 2 shown in FIG. In conjunction therewith, it rotates at a low speed such that it makes one rotation in one turning operation (for example, 15 seconds). In this manner, the X-ray moving speed on the tomographic plane of the subject P and the peripheral surface moving speed of the rotary drum 312 are linked so that the X-rays enter the X-ray imaging device 310 from the secondary slit 352, and Are recorded on the stimulable phosphor sheet 311.

Next, an image reading operation will be described.
The rotating drum 312 is rotated at a high speed of, for example, 1024 rpm by a motor 363 for high-speed rotation, and the laser 321 and the photomultiplier 325 are moved by, for example, 0.1 mm per rotation of the rotating drum 312. The X-ray energy stored in the stimulable phosphor sheet 311 is converted into stimulated emission by the excitation light, and the photomultiplier 325 is converted into an electric signal corresponding to the intensity of the stimulated emission. The tomographic images thus photographed are read out as time-series image signals, and are read out as digital data in the frame memory 34.
6 and subjected to desired signal processing and displayed.

When a series of reading operations is completed, the erasing lamp 320 is turned on and the rotating drum 312 is rotated, and the remaining X-ray energy is released to prepare for the next X-ray imaging.

As described above, in the case of panoramic photography, FIG.
8, the X-ray generator 301 and the X-ray imager 310
Each of the slits 351 and 352 is held vertically, and the subject P is irradiated with a vertical slit-shaped X-ray beam. On the other hand, in the case of cross-sectional imaging, the rotation mechanisms 360 and 362 are driven to drive the X-ray generator 301 and the X-ray imaging device 3.
The subject P is irradiated with a horizontal slit-shaped X-ray beam while holding each of the ten slits 351 and 352 horizontally. Thus, panoramic radiography and cross-layer radiography can be selectively performed by the same device.

FIG. 20 is an overall configuration diagram showing still another embodiment of the present invention. As in FIG. 18, the X-ray generator 301 and the X-ray imaging device 3
The X-ray generator 301 and the X-ray imaging device 310 are installed around the irradiation center axis connecting the X-ray generation unit and the X-ray detection unit. It is mounted so that it can rotate freely.

In the X-ray imaging device 310, the stimulable phosphor sheet 311 is provided on a peripheral surface of a hollow and translucent rotating drum 312, and the rotating drum 312 is driven to rotate by a rotating mechanism 363. The rotating mechanism 361 is a mechanism for releasing the X-ray generator 301 from the facing relationship with the X-ray imaging device 310 during cephalometric imaging.

A laser 321 such as a semiconductor laser is used as an excitation light source for irradiating the stimulable phosphor sheet 311 with excitation light, and is disposed inside the rotating drum 312. The excitation light emitted from the laser 321 is converged by the lens 322, passes through the light-transmitting rotating drum 312, and enters substantially perpendicularly from the inside of the stimulable phosphor sheet 311. From the portion irradiated with the excitation light, stimulated emission is generated according to the X-ray energy stored in the stimulable phosphor sheet 311. The stimulated emission emitted outside the rotating drum 312 is received by a photomultiplier (photomultiplier tube) 325 installed close to the stimulable phosphor sheet 311. The light receiving surface of the photomultiplier 325 is provided with an optical filter that blocks excitation light and passes only stimulated emission.

The photomultiplier 325 is mounted on the screw shaft 326, and moves linearly at a constant speed along the axial direction of the rotary drum 312 by the rotation of the motor 327. The laser 321 is mounted on a screw shaft 329 and linearly moves at a constant speed along the axial direction of the rotating drum 312 by the rotation of the motor 330. Laser 321 is Photomaru 3
The motor 327 and the motor 330 rotate in synchronism with each other so as to always face the H.25, and perform sub-scanning during reading. On the other hand, when scanning, the main scanning
12 rotations. Stimulable phosphor sheet 31
When the two-dimensional scanning of 1 is completed, the erasing lamp 320 is turned on with the rotation of the rotating drum 312, and the remaining X-ray energy is entirely erased.

The electric configuration of the motor drive system and the image signal processing system is the same as that shown in FIG. 19, and the description thereof will not be repeated.

As described above, in the case of panoramic photography, FIG.
0, the X-ray generator 301 and the X-ray imager 310
Is held vertically, and the subject P is irradiated with a vertical slit-shaped X-ray beam. On the other hand, in the case of cross-sectional imaging, the X-ray generator 301 and the X-ray imager 310 are held horizontally,
The subject P is irradiated with a horizontal slit-shaped X-ray beam. Thus, panoramic radiography and cross-layer radiography can be selectively performed by the same device.

FIG. 21 is an overall configuration diagram showing still another embodiment of the present invention. As in FIG. 18, the X-ray generator 301 and the X-ray imaging device 3
The X-ray generator 301 and the X-ray imaging device 310 are installed around the irradiation center axis connecting the X-ray generation unit and the X-ray detection unit. It is mounted so that it can rotate freely.

The X-ray imaging device 310 has a secondary slit 352
And a CCD sensor 370 that is a linear sensor,
The X-ray image passing through the subject P is converted into an electric signal.

As described above, in the case of panoramic photography, FIG.
1, the X-ray generator 301 and the X-ray imager 310
Is held vertically, and the subject P is irradiated with a vertical slit-shaped X-ray beam. On the other hand, in the case of cross-sectional imaging, the X-ray generator 301 and the X-ray imager 310 are held horizontally,
The subject P is irradiated with a horizontal slit-shaped X-ray beam. Thus, panoramic radiography and cross-layer radiography can be selectively performed by the same device.

FIG. 22A is an overall configuration diagram showing still another embodiment of the present invention. An X-ray generator 301 and an X-ray imager 310 are installed at both ends of the turning arm 302 so as to face each other. The X-ray generator 301 has the configuration shown in FIG.
And a double focus X-ray tube 353 as shown in FIG.
It has a primary slit 351 and the like that can change the direction of 1a,
The subject is irradiated with a vertical or horizontal slit-shaped X-ray beam.

FIG. 22B is a front view in which the opening 351a of the primary slit 351 is set in the vertical direction.
(C) is a front view in which the opening 351a of the primary slit 351 is set in the horizontal direction. The primary slit 351 is X
The primary slit 351 is rotatably mounted on the emission port of the wire tube 353, and the user manually adjusts the direction of the primary slit 351. FIG.
(B) shows a setting for panoramic photography, in which an opening 351a is provided.
Is in the vertical direction, so that a vertical slit-shaped X-ray beam is generated. On the other hand, FIG. 22C shows a setting for cross-layer imaging, and since the opening 351a is in the horizontal direction, a horizontal slit-shaped X-ray beam is generated.

As the direction of the primary slit 351 changes, the direction of the X-ray imaging device 310 is also adjusted. The X-ray imaging device 310 is attached to the turning arm 302 via the rotation mechanism 362, and is rotatable around an irradiation center axis connecting the X-ray generation unit and the X-ray detection unit. FIG.
In 2, the X-ray imager 310 is held in a vertical position, the secondary slit 352 is positioned in the vertical direction, and receives a vertical slit-shaped X-ray beam to take an arrangement for panoramic imaging. On the other hand, when the X-ray imaging device 310 is held in a horizontal posture by the rotation mechanism 362, the secondary slit 35
2 is positioned in the horizontal direction, receives an X-ray beam in the form of a horizontal slit, and takes an arrangement for cross-sectional imaging. Note that the internal configuration of the X-ray imager 310 is the same as in FIG.
Omit duplicate explanations.

As described above, in the case of panoramic photography, FIG.
2, the X-ray generator 301 and the X-ray imager 310
Is held vertically, and the subject P is irradiated with a vertical slit-shaped X-ray beam. On the other hand, in the case of cross-sectional imaging, the X-ray generator 301 and the X-ray imager 310 are held horizontally,
The subject P is irradiated with a horizontal slit-shaped X-ray beam. Thus, panoramic radiography and cross-layer radiography can be selectively performed by the same device.

[0120]

As described above, according to the present invention, it is possible to realize cross-sectional imaging with a small configuration. In addition, since cross-sectional imaging and panoramic imaging can be selectively performed by the same apparatus, reduction in apparatus cost and installation area can be achieved.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of an X-ray tomography apparatus 1 according to an embodiment of the present invention, with a part cut away.

FIG. 2 is a cross-sectional view showing an internal configuration of a support column 3.

FIG. 3 is a sectional view showing a schematic configuration of a position adjusting mechanism 22 and a turning mechanism 21 provided in a main body 19.

FIG. 4 is a plan view of the position adjusting mechanism 22.

FIG. 5 is a cross-sectional view showing a schematic configuration of an elevating mechanism 31 provided in a columnar body 3 for displacing the elevating body 10 up and down.

FIG. 6 is a view showing a schematic configuration of a guiding mechanism provided in the lifting body for guiding the vertical position of the lifting body.

FIG. 7 is a perspective view showing a configuration of an X-ray generator 7 and a rotation mechanism 41 for the X-ray generator incorporated in the support arm 5.

FIG. 8 is a perspective view showing a configuration of an X-ray image detecting means 6 provided in the support arm 5.

FIG. 9 is a block diagram showing an electrical configuration of a control circuit 61 provided in the main body 19.

FIG. 10 is a block diagram showing an electrical configuration of an image information processing circuit 66 provided in the X-ray tomography apparatus 1.

FIG. 11 is a perspective view showing a configuration of an X-ray image detecting means provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 12 is a perspective view showing a configuration of an X-ray image detecting means 206 provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 13 is a perspective view showing a configuration of an X-ray generator 107 and an irradiation field shape switching mechanism 141 provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 14 is a perspective view showing a configuration of an irradiation field shape switching mechanism 241 provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 15 is a perspective view showing a configuration of an irradiation field shape setting mechanism 102 provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 16 is a perspective view showing a configuration of an irradiation field shape setting mechanism 202 provided in an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 17 is a perspective view showing a partial configuration of an X-ray tube 110 provided in an X-ray generator of an X-ray tomography apparatus according to another embodiment of the present invention.

FIG. 18 is an overall configuration diagram showing still another embodiment of the present invention.

19 is a configuration diagram showing the X-ray imager 310 of FIG.

FIG. 20 is an overall configuration diagram showing still another embodiment of the present invention.

FIG. 21 is an overall configuration diagram showing still another embodiment of the present invention.

FIG. 22A is an overall configuration diagram showing still another embodiment of the present invention, and FIG. 22B is a front view in which an opening 351a of a primary slit 351 is set in a vertical direction. FIG. 22C shows an opening 3 of the primary slit 351.
It is the front view which set 51a to the horizontal direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 X-ray tomography apparatus 2 U-shaped base 3 Columnar body 4 Suspension body 5 Support arm 6,106,206 X-ray image detection means 7,107 X-ray generator 8 Jaw fixed body 9 Head fixing mechanism 10 Elevating body 11 Operation Command input unit 16 Image information processing device 17 Display device 19 Main body 21 Turning mechanism 21d, 22g, 22j, 31a, 36a, 41c, 8
0, 83, 87, 92, 101 Pulse motor 22 Position adjustment mechanism 31 Elevation mechanism 36 Automatic positioning mechanism 37, 58-60 Sensor 41 Rotation mechanism for X-ray generator 46, 47, 82 Linear sensor 49 FOP 50 Scintillator 51 X-ray Generation circuit 52 Control unit 53 to 57 Motor drive circuit 61 Control circuit 66 Image information processing circuit 67 Synchronous signal output circuit 68 Amplification circuit 69 Analog / digital conversion circuit 70 Main memory 71 CPU 72 Recording device 73 Display memory 76 Drum 102, 202 Irradiation Field shape setting mechanism 110 X-ray tubes 111, 112 Filament 113 Target 141, 241 Irradiation field shape switching mechanism 301 X-ray generator 302 Revolving arm 303 Rotary table 304 XY table 305 Fixed arm 310 X-ray imager 311 Storage Stackable phosphor sheet 312 Rotating drum 317 Detection member 320 Erase lamp 321 Laser 325 Photomultiplier (Photomultiplier tube) 326, 329 Screw shaft 340, 342 CTC (Counter timer circuit) 343 Integrator circuit 344 S / H (Sampling and hold) ) Circuit 345 A / D (analog-digital conversion) circuit 346 Frame memory 347 Display device

────────────────────────────────────────────────── ─── Continuation of the front page Examiner Akio Yasuda (56) References JP-A-5-264475 (JP, A) JP-A-6-181 (JP, A) JP-A-6-277214 (JP, A) JP-A-2-84942 (JP, A) JP-A-61-103143 (JP, A) JP-A-8-308829 (JP, A) JP-A-2-39705 (JP, U) (58) Int.Cl. ⁷ , DB name) A61B 6/00-6/14

Claims (5)

(57) [Claims] 1. A support, an X-ray source and an X-ray image detecting means supported by the support and arranged on both sides of the subject so as to face each other, and the support can be turned around the subject. Turning means, wherein the X-ray source has an opening extending in the horizontal direction and the vertical direction on the front surface, or the opening and the turning direction and the shape can be changed in the horizontal direction and the vertical direction. A primary slit that generates a fan beam that extends vertically,
An X-ray tube that generates X-rays in the horizontal and vertical directions is provided therein. The X-ray image detecting means has an opening in the front and in the horizontal and vertical directions for receiving X-rays from the X-ray source. A panoramic X-ray comprising a secondary slit which is extended or whose opening can be changed in direction and shape in the horizontal and vertical directions, and X-ray image detecting means which is extended in the horizontal and vertical directions In the case of imaging, a primary slit having an opening extending in the vertical direction is selected, and the X-ray image detecting means is disposed in the vertical direction, and a secondary slit having the opening extending in the vertical direction on the front surface. In the case of photographing a cross section of a subject, a primary slit having an opening extending in the horizontal direction is selected, and the X-ray image detecting means is disposed in the horizontal direction. A secondary slit extending in the lateral direction can be selected, and the X-ray image Medical equipment characterized in that the output means has a rotating means capable of changing the direction in the vertical direction and the horizontal direction according to the panoramic radiography and the cross-sectional radiography, and can perform both panoramic radiography and cross-sectional radiography. X-ray tomography apparatus for use. 2. A base, a support standing upright on the support, an elevating body capable of adjusting a vertical position with respect to the support, A medical device comprising: a support having a turning means for horizontally turning an X-ray source and an X-ray image detecting means disposed opposite to each other around a subject; and a fixing means disposed on the support or the elevating body for positioning the subject. An X-ray tomography apparatus for X-ray, wherein the X-ray source has an opening extending in a horizontal direction and a vertical direction on a front surface thereof, or the opening can be turned or changed in a horizontal direction and a vertical direction. A primary slit that generates a fan beam that spreads horizontally and vertically,
An X-ray tube for generating X-rays therein, wherein the X-ray image detecting means has an opening extending in the horizontal and vertical directions for receiving X-rays from the X-ray source on the front surface, Alternatively, a secondary slit capable of turning or changing the shape of the opening in the horizontal and vertical directions, and an X disposed inside.
In the case of panoramic X-ray photography, a primary slit having an opening extending in the vertical direction is selected, and the X-ray image detecting means is disposed in the vertical direction, and an opening is provided on the front surface. In the case of photographing a cross section of a subject, a primary slit having an opening extending in the horizontal direction is selected, and the X-ray image detecting means is used to select a secondary slit in which the opening is extended in the horizontal direction. The X-ray image detecting means is capable of selecting a secondary slit having an opening portion extending in the horizontal direction on the front side, and the X-ray image detecting means is capable of performing the direction in the vertical direction and the horizontal direction according to the panoramic imaging and the cross-sectional imaging. A medical X-ray tomography apparatus, characterized in that the medical X-ray tomography apparatus has a rotating means capable of conversion, and is capable of performing both panoramic imaging and cross-sectional imaging. 3. The X-ray image detecting means is one of a stimulable phosphor sheet, an X-ray CCD sensor, a MOS sensor, an X-ray fluorescence intensifier, and an SIT (silicon intensifier). The medical X-ray tomography apparatus according to claim 1 or 2, wherein: 4. An X-ray image detecting means comprising: a stimulable phosphor sheet provided around a rotary drum; an excitation light source for irradiating the stimulable phosphor sheet with excitation light; A light receiving unit for receiving stimulated emission from the phosphor sheet; a rotation driving unit for rotating the rotating drum to perform main scanning; and a sub-unit for moving the excitation light source and the light receiving unit along the axis of the rotating drum. The medical X-ray tomography apparatus according to claim 1, further comprising a linear drive unit for performing scanning. 5. The X-ray source according to claim 1, wherein said X-ray source is capable of turning an X-ray beam surface in a vertical direction and a horizontal direction, or is capable of irradiating the X-ray beam surface in a vertical direction and a horizontal direction. The medical X-ray tomography apparatus according to any one of claims 1 to 4, wherein the medical X-ray tomography apparatus has any one of a dual-focus X-ray tube.