JP3207050B2 - Tomographic X-ray equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tomographic X-ray apparatus used for planar tomography and / or curved tomography in medical treatments such as dentistry and otolaryngology.

[0002]

2. Description of the Related Art In recent years, a curved tomography X-ray apparatus for photographing a curved tomography such as a dental arch used in medical treatments such as dentistry and otolaryngology has been developed to detect a specific site with a narrow tomographic width such as a jaw joint or a dental implant. Devices having a plane tomography function for selectively capturing images have become widespread. When performing a plane tomography in such a curved tomography X-ray apparatus, for example, in order to perform a tomography on a desired plane tomographic plane of a dental arch, a specific part where the plane tomography of the dental arch is to be performed is specified. It is necessary to determine the information and set the information on the position of the determined portion in the curved tomographic X-ray imaging apparatus.

A conventional technique for selectively determining a specific portion in a dental arch or the like and setting position information relating to the position of the determined portion in an apparatus is disclosed in Japanese Patent Application Laid-Open No. Sho 62-183.
749. In this prior art, first, a curved tomographic image of a dental arch, that is, a so-called panoramic image is taken, and the taken curved tomographic image is set at a predetermined position on a dedicated sharksten provided with a scale. Next, the marker line is moved to the position of the plane tomographic plane to be photographed on the curved tomographic photograph, and the position information represented by the scales and numerals on the scale supported by the marker line is read. The position information of the position to be subjected to planar tomography in the dental arch thus obtained is input to the device, and the device performs planar tomography of a portion corresponding to the position information of the dental arch based on the input position information. Do.

[0004]

In the above-mentioned prior art,
A curved tomographic image of the dental arch is placed on a scale provided with a scale, and the position of the plane tomographic plane to be photographed on the curved tomographic image is compared with positional information on the scale to input to the device. Since the position information to be obtained is obtained, a deviation occurs between the curved tomographic image and the scale on the Schaukasten due to an installation error when the curved tomographic image is installed on the Schakkasten, and accurate position information to be input to the device can be obtained. Absent. If accurate position information is not obtained in this way, a deviation occurs between the plane tomographic plane to be photographed and the plane tomographic plane to be photographed, and a plane tomographic photograph of a desired portion of the dental arch is obtained. Absent. In addition, in order to derive the position information to be input to the apparatus from the curved tomographic image, it is necessary to accurately set the curved tomographic image at a predetermined position on the Schakkasten. It is messy.

Further, in order to derive positional information to be input to the apparatus at the time of planar tomography from a photographed curved tomographic image, a dedicated sharksten provided with a scale is required. When an apparatus according to the prior art is introduced, a dedicated shakasten is introduced together with the apparatus, which increases the introduction cost.

An object of the present invention is to provide a tomographic X-ray apparatus capable of accurately deriving a position of a plane tomographic plane to be imaged and improving operability.

[0007]

According to the present invention, there is provided an X-ray generator and X-ray detecting means provided with a subject interposed therebetween, and the X-ray detecting means.
X-ray generator driving means for driving the X-ray generator to control the position of the X-ray generator, and X-rays for driving the X-ray detection means to control the position of the X-ray detecting means A detection means driving means, position data storage means for storing position control data for each of one or more predetermined plane tomographic planes corresponding to the subject, and position information corresponding to the plane tomographic plane to be imaged. Input means for inputting,
Based on the position information input by the input means, the driving means for the X-ray generator and / or the driving means for the X-ray detection means are controlled by the position control data stored in the position data storage means, so that the curved tomography is performed. And a tomographic X-ray apparatus for performing plane tomography, wherein the X-ray detection means is provided with position information recording means for recording position information corresponding to the plane tomographic plane on a detection surface of the X-ray detection means,
A tomographic X-ray apparatus characterized in that a plane tomographic plane to be imaged is selected by the input means based on position information recorded on a detection surface. Further, according to the present invention, the position information recording means holds an X-ray recording medium having a photosensitive surface,
In a portion facing the X-ray recording medium, position information of one or more predetermined plane tomographic planes corresponding to a subject is recorded on the X-ray recording medium.

[0008]

According to the present invention, curved tomography is performed while exposing position information of one or more predetermined plane tomographic planes corresponding to the subject to the detection surface of the X-ray detection means. Since the position information of the predetermined plane tomographic plane of the subject is exposed to the curved tomographic image thus photographed, the X-ray detection including the X-ray film or the like which has occurred in the above-described conventional technique is performed. The displacement between the curved tomographic image recorded in the means and the scale provided on the sharksten can be eliminated. The curved tomographic image obtained as described above includes
Since the positional information is exposed, it is not necessary to accurately set the X-ray detecting means for aligning the position of the scale and the curved tomographic image on the Schaukasten as in the prior art. It is possible to improve the operability when the means is installed on the shakasten.

Further, according to the present invention, based on the curved tomographic image photographed as described above, one piece of positional information is selected from the positional information contained in the curved tomographic image, and the selected positional information is selected. The plane tomographic plane to be photographed is determined based on the above, and the plane tomography is performed. Therefore, since one piece of position information is selected based on a curved tomographic image having position information, one piece of positional information is accurately selected without a shift between the curved tomographic image and the scale unlike the related art. As a result, the plane tomographic plane of the subject to be photographed can be accurately determined. As a result, a desired planar tomographic plane of the subject can be accurately photographed.

According to the present invention, in the tomography of a curved surface by the tomographic X-ray imaging apparatus, the X-ray generator and the X-ray detecting means are driven by the X-ray generator driving means and the X-ray generator while the X-ray flux is irradiated by the X-ray generator. The rotation is performed around the subject by the driving means for the X-ray detection means. At this time, the X-ray detecting means is driven by the driving means for the X-ray detecting means in a tangential direction of the direction in which the X-ray detecting means is turned at a moving speed corresponding to the turning speed of the X-ray generator and the X-ray detecting means. Be moved. When the curved tomography is performed in this manner, the above-described plurality of pieces of position information are exposed to the curved tomographic image recorded in the X-ray detection unit.

In order to perform plane tomography, it is necessary to determine a plane tomographic plane to be photographed of a subject. The plane tomographic plane is determined based on the curved tomographic image obtained as described above. Will be Based on the curved tomographic image, one piece of position information corresponding to a desired plane tomographic plane is selected, and when the selected position information is input by the input unit, the plane tomographic plane stored in advance in the position data storage unit is stored. Position control data corresponding to the input position information of the surface position control data is determined, and imaging of a plane tomographic plane is performed based on the position control data.

For plane tomography, first, the X-ray generator and the X-ray detector are driven by the X-ray generator drive and the X-ray generator.
By the position control based on the position control data by the line detecting means driving means, the straight line connecting the X-ray generator and the X-ray detecting means is perpendicular to the plane tomographic plane to be photographed of the subject determined as described above. It is moved to the position where it intersects. When the X-ray generator and the X-ray detector are moved in this way, the plane tomography is performed while the X-ray generator irradiates the X-ray flux while the X-ray generator is parallel to the plane tomographic plane to be imaged. The X-ray detector is moved linearly in the direction
This is performed by linearly moving the line generator in a direction opposite to the moving direction.

[0013]

[0014]

FIG. 1 is a perspective view showing an internal structure of an X-ray film cassette 7 used in a tomographic X-ray apparatus 51 according to one embodiment of the present invention. X-ray film cassette 7 used for curved tomography by tomographic X-ray apparatus 51
Is provided with a cassette body 81 and a lid 82 that is attached to the cassette body 81 so as to be freely opened and closed.

Intensifying screens 81a and 82a are provided on the inner bottom surface of the cassette body 81 and the inner surface of the lid 82.
An X-ray film (not shown) is sandwiched between intensifying screens 81a and 82a. The intensifying screen 81a on the X-ray source 6 side includes, on the X-ray film, positional information corresponding to a plurality of plane tomographic planes L1 to L21 to be described later, which are set in advance in the lower jaw and the dental arch of the patient as the subject. A photosensitive pattern 81b for exposing is provided. The photosensitive pattern 81b is formed from a light-shielding material.

FIG. 2 is a partially cutaway side view showing the structure of the tomographic X-ray apparatus 51 in which the X-ray film cassette 7 shown in FIG. 1 is mounted. FIG. 3 shows a tomographic X-ray imaging apparatus 51.
FIG. 3 is a partially cutaway perspective view showing the configuration of FIG. FIG. 4 is a partially cutaway perspective view showing a partial configuration of the tomographic X-ray imaging apparatus 51.

The tomographic X-ray apparatus 51 includes a base 1, an XY
Table 2, turning mechanism 3, support arm 4, X-ray source 6, X
It comprises a linear film cassette 7 and a linear slide mechanism 8. The X-ray generator 6 and the X-ray film cassette 7 are supported by the support arm 4 so as to face each other with the subject therebetween. The X-ray generator 6 and the X-ray film cassette 7 supported as described above are turned by turning the support arm 4 by the turning mechanism 3, and the turning center position of the support arm 4 is adjusted by the XY table 2. . Therefore, the support arm 4 is supported by the base 1 via the XY table 2 and the turning mechanism 3. The linear slide mechanism 8 linearly moves the support arm 4 in a direction perpendicular to the longitudinal direction of the support arm 4, and the X-ray source 6 is moved with the linear movement of the support arm 4. X-ray film cassette 7
Is linearly moved in the direction opposite to the direction in which the support arm 4 is moved, as described later. The X-ray source 6 and the X-ray film cassette 7 are attached to both ends of the support arm 4 so as to face each other.

The XY table 2 includes an X-axis motor 2a for adjusting the position in the X-axis direction, a guide mechanism 2b, a Y-axis motor 2c for adjusting the position in the Y-axis direction, and a guide mechanism 2
d and a slide member 2e.
The slide member 2e moves in the XY plane in accordance with the driving of the slide members 2a and 2c, and the position of the turning mechanism 3 attached to the lower portion of the slide member 2e is controlled. The above-mentioned guide mechanisms 2b and 2d are composed of rollers 2f and 2g rotatable by bearings, respectively, and guide frames 2h and 2j having guide grooves for these rollers.

The turning mechanism 3 is a belt mechanism 3 comprising a turning motor 3a and a pulley and a belt for transmitting the rotation.
b, and the revolving unit 3 around which the belt mechanism 3b is wound
c, etc., and the revolving unit 3c is rotatably supported by the slide member 2e of the XY table 2 via a bearing 3d. Therefore, the motor 3a
, The revolving unit 3 c pivots, and the revolving unit 3
Similarly, the support arm 4 attached to the lower part of c rotates.

The linear slide mechanism 8 includes a driving motor 8
a, and a screw shaft 8c for movement which transmits the rotation thereof via a belt mechanism 8b, a guide mechanism 8d, and the like. The driving motor 8a is fixed to the support arm 4, the moving screw shaft 8c is rotatably mounted on the support arm 4, and the guide mechanism 8d is a guide frame 8e mounted on the revolving unit 8c and the support arm 4 And a slide member 8g integrally formed on the upper surface of the guide frame 8e and supported by a guide frame 8e via a roller 8f. A connecting body 8h is integrally fixed to the lower surface of the guide frame 8e, and a moving screw shaft 8c is screwed with a female screw body 8j provided at the lower end thereof. The female screw body 8j moves relatively in the axial direction.

Therefore, by turning the whole of the linear slide mechanism 8 below the guide frame 8e and the support arm 4 by the turning mechanism 3, the moving direction by the guide frame 8e is set to be parallel to an arbitrary plane tomographic plane. It is possible,
By driving the driving motor 8a in this state,
The support arm 4 can be moved linearly (in the example of FIG. 2, in a direction perpendicular to the paper surface) along the guide frame 8e.

The support arm 4 is provided with a rotation motor 6 a for rotating the X-ray source 6 with respect to the support arm 4, and the X-ray flux is constantly changed with the movement of the support arm 4. It is configured to rotate about a vertical direction as an axis so as to be irradiated toward the film cassette 7.

On the X-ray film cassette 7 side, a housing 7 supported by the support arm 4 by a slide mechanism 7a is provided.
The housing 7d is provided with a holder 7g supported by a slide mechanism 7e and moved by a drive motor 7f. The X-ray film cassette 7 is housed in the holder 7g. A belt mechanism 7 for transmitting the rotation of the driving motor 8a is provided at an upper portion of the housing 7d.
b, and a moving screw shaft 7c which is rotated by this, and a sliding member 7i fixed to the housing 7d is screwed to the moving screw shaft 7c. Therefore, when the driving motor 8a is driven and the support arm 4 moves,
In conjunction with this, the slide member 7e, that is, the housing 7d moves together with the X-ray film cassette 7 in the direction opposite to the movement of the support arm 4.

Since the tomographic X-ray apparatus 51 is an apparatus capable of performing curved tomography and planar tomography, the shape of the irradiation field of the X-ray emitted from the X-ray source 6 and the shape of the light received on the X-ray film cassette 7 are determined. Needs to be changed according to the purpose. Therefore, the X-ray source 6 is provided with an irradiation field shape switching plate 6b and its driving motor 6c, and the X-ray film cassette 7 is provided with a light receiving shape switching plate 7h and its driving motor 7j. .

In FIG. 3, the support unit 1a incorporates an X-axis mechanism 2 such as an X-axis motor 2a and a guide mechanism 2b of the XY table 2, a turning mechanism 3, and the like.
A fixing mechanism 1b for fixing the patient's head is provided between the X-ray source 6 and the X-ray film cassette 7, and a patient's chair 1c is provided below the fixing mechanism 1b. The height of the base 1 can be freely adjusted according to the sitting height of the patient sitting on the chair 1c.

The control panel 12, which is a selection means provided on the base 2, sets the intensity of the X-ray flux to be irradiated, sets the irradiation time of the X-ray flux, adjusts the height of the fixing mechanism 8 and the support arm 5, and performs curved tomography. And a plurality of input keys 12a, which are used to set whether to perform tomography or plane tomography, and to input a plane tomographic plane to be photographed from among a plurality of plane tomographic planes set in advance to be described later to the tomographic X-ray imaging apparatus 51. And display unit 1
2b.

FIG. 5 is a block diagram showing an electrical configuration of a drive circuit of the tomographic X-ray imaging apparatus 51. The drive circuit of the tomographic X-ray apparatus 51 includes a control unit 11 having a CPU (Central Processing Unit), a control panel 12, an X-ray generation circuit 13,
It comprises drive circuits 21 to 28 for various motors, sensors 33 to 38 for the position and angle of each part, and a memory 39. When the surgeon operates the control panel 12 to input a command for instructing the imaging style, the control unit 11 outputs a predetermined signal in accordance with one of the plane tomography and the curved tomography in each of the motor drive circuits 21 to 28. Is output to Thus, each motor is driven, and the result is detected by each of the sensors 33 to 38 and is fed back to the control unit 11.

The memory 39 stores position control data of a plurality of predetermined plane tomographic planes of the subject.
The control unit 11 drives and controls each motor based on the position control data stored in the memory 39, and captures a plane tomographic plane to be captured. Examples of the predetermined plurality of plane tomographic planes will be described later with reference to FIG.

FIG. 6 is a cross-sectional view showing the structure of an X-ray film cassette 7 used for curved tomography by the tomography apparatus 51. FIG. 7 is a diagram showing a plurality of predetermined plane tomographic planes L1 to L21 in the lower jaw 71.

Referring to FIG. 7, lower jaw 71 and lower jaw 71
The plane tomographic plane perpendicular to the lower jaw 71 and the dental arch 72 of the dental arch 72 is predetermined by 21 plane tomographic planes L1 to L21, and position information based on the plane tomographic planes L1 to L21 is It is recorded in the aforementioned memory 39. The plane tomographic plane L11 is a tomographic plane passing through the center of the lower jaw 71 and the dental arch 72, and the planar tomographic planes L1 to L10 are
Is set so as to divide the portion from the plane tomographic plane L11 to the right side, that is, a part slightly before the left end toward the patient, and the plane tomographic planes L12 to L21 are similarly set in the lower jaw 7.
1 is set so as to equally divide the left part.

Here, the number of planar tomographic planes L1 to L21 of the lower jaw 71 and the dental arch 72 is set to 21, or is not limited to 21, and may be larger or smaller. In addition, although examples of the plane tomographic planes L1 to L21 set on the lower jaw 71 and the dental arch 72 are shown, the present invention is not limited to the lower jaw 71 and the dental arch 72, and for example, the upper jaw, the dental arch of the upper jaw, or the plane of the skull The tomographic plane can be set similarly.

The X-ray film cassette 7 has a rectangular box-shaped cassette body 81 made of an X-ray transparent material as described above, and a plate-shaped lid 82 having a size just fitted into the cassette body 81. It is comprised including. Lid 82
Is attached to the cassette main body 81 by two hinges 83, and can be opened and closed by, for example, 180 ° angular displacement from a closed state fitted in the cassette main body 81.

Intensifying screens 81a and 82a that emit visible light from a portion where X-rays are incident are provided on the bottom surface inside the cassette body 81 and the inner surface of the lid 82. X-ray film 9 coated on both sides with a photosensitive agent sensitive to visible light
Reference numeral 6 is provided in the X-ray film cassette 7, and is held between the bottom surface inside the cassette main body 81 and the inside surface of the lid 82. By providing a sheet-like resilient member 82b made of sponge, rubber or the like between the inner surface of the lid 82 and the intensifying screen 82a, the intensifying screens 81a, 82a and the X-ray film 96 are more closely adhered to each other. It has become. By doing so, the intensifying screens 81a and 82a and the X-ray film 96
Can be prevented from occurring, and a clearer tomographic image can be recorded.

Intensifying screen 81 provided in cassette body 81
In a, a photosensitive pattern 81b as a position information recording means is provided on the surface on the X-ray film 96 side. The photosensitive pattern 81b formed of a light-shielding material partially shields visible light emitted from the intensifying screen 81a when X-rays are incident thereon, and exposes the X-ray film 96 to position information 91 described later.

Here, the photosensitive pattern 81b is formed by the intensifying screen 8
1a. Also, the photosensitive pattern 81b
Is formed of a light-shielding material. However, for example, when the photosensitive pattern 81b is provided between the X-ray source 6 and the intensifying screen 81a, it may be formed of a material that blocks X-rays. Good.

The photosensitive pattern 81b has graduations 81c for sensitizing the graduations individually corresponding to the plane tomographic planes L1 to L21 described above, and the graduations 81c, respectively.
Index portion 81 that exposes the index represented by “1” to “21”
d and an index portion 81e that exposes an index represented by “R” or “L” for identifying left and right of the recorded tomographic image.
Is formed.

The curved tomography by the tomographic X-ray apparatus 51 constructed as described above is performed as follows. Here, a case where curved tomography of the upper and lower jaws of a patient is performed will be described. First, the patient is seated on the chair 1c, and the patient's head is fixed by the fixing mechanism 1b. Next, the operator uses the control panel 21 to operate the tomographic X-ray imaging apparatus 5.
When the start of curved tomography is instructed to 1, imaging by the tomographic X-ray imaging apparatus 51 is started.

When the imaging is started, the X-ray
While the beam is being irradiated, the support arm 4 is turned by the turning mechanism 3, so that the straight line connecting the X-ray source 6 and the X-ray film cassette 7 is substantially perpendicular to the left or right end of the upper and lower jaws. The X-ray sources 6 and X are moved from the state of intersection to the state of intersection with the right or left end substantially vertically.
The line film cassette 7 is turned. As the support arm 4 is turned, the XY table is maintained such that the direction of the straight line connecting the X-ray source 6 and the X-ray film cassette 7 is substantially perpendicular to the direction in which the dental arch is arranged. 2, the center of rotation of the support arm 4 is moved.

As the support arm 4 turns,
The motor 7f is driven, and the X-ray film cassette 7 is moved at a moving speed corresponding to the turning speed of the support arm with respect to the slit provided in the light receiving shape switching plate 7h. At this time, the X-ray flux passing through the upper jaw and the lower jaw of the patient is applied to the X-ray film cassette 7 from the bottom side of the cassette body 81.
The light enters the line film cassette 7. In this way,
When an X-ray flux is incident, curved tomographic images of the upper jaw and the lower jaw are recorded while the position information 91 is exposed to the X-ray film by the above-described photosensitive pattern 81b.

FIG. 8 shows an X-ray film 9 as described above.
6 is a front view of a curved tomographic image 97 of an upper jaw and a lower jaw having position information 91 recorded in No. 6. FIG. The position information 91 includes a scale portion 81c of the photosensitive pattern 81b, a scale 91c formed by being exposed by the index portions 81d and 81e,
Indices 91d and 91e are included. The position of each scale 91c in the left-right direction in FIG. 8, ie, the arrangement direction of the dental arch, coincides with the positions of the predetermined plane tomographic images L1 to L21 in the curved tomographic image 97 in FIG.

For example, in FIG. 8, the position of the scale 91c in the left-right direction corresponding to “3” of the index 91d is, as shown by the phantom line 99, the position in the left-right direction of the right end of the lower dental arch. This corresponds to the position of the plane tomographic plane L3 set at the right end of the dental arch 72 of the lower jaw 71 shown in FIG.

Here, the position information 91 is exposed at the lower end in FIG. 8 of the X-ray film 96, but may be exposed not only at the lower end but also at the upper end. In this embodiment, one type of position information 91 is exposed on the X-ray film 96. However, a plurality of types of position information corresponding to a plurality of sizes are exposed, for example, according to the size of the upper and lower jaws of a patient. You may make it. For example, a wide scale 91c corresponding to the size of the upper and lower jaws of an adult
The X-ray film cassette 7 is used for an adult and a child by exposing the position information having the graduations 91 and the position information having the graduations 91c with a narrow interval corresponding to the size of the upper and lower jaws of the child to be arranged vertically. be able to.

Further, in the present embodiment, the position information 91 is exposed by partially blocking the visible light emitted from the intensifying screen 81a. The same positional information 91 may be exposed by partially transmitting visible light in the light-shielded area.

In order to photograph a plane tomographic plane, first,
It is necessary to determine a plane tomographic plane to be imaged, and the plane tomographic plane is determined based on the curved tomographic image recorded as described above. Here, a case where the upper and lower jaw plane tomographic planes are determined based on the upper and lower jaw curved tomographic images 97 will be described. Based on the curved tomographic image 97 recorded as described above, for example, when an attempt is made to photograph a plane tomographic plane at the right end of the lower dental arch of a patient, the right side of the lower dental arch to be photographed is taken. Figure 8 at the end
The index 91d corresponding to the scale 91c closest to the position in the left-right direction in FIG.
“3” is input to the cross-sectional X-ray imaging apparatus 51 by the input key 12 a of the control panel 12. When the index “3” corresponding to the plane tomographic plane to be imaged is input in this way,
The position control data of the plane tomographic plane L3 corresponding to the index “3” is read from the memory 39, and plane tomography is performed by the tomographic X-ray imaging apparatus 51.

The plane tomography is performed as follows. Here, a case will be described in which a planar tomographic plane of the upper and lower jaws of a patient is imaged. As in the case of the above-described curved tomography, when the patient's head is fixed by the fixing mechanism 1b, the support arm 4 is turned by the turning mechanism 3, and a straight line connecting the X-ray source 6 and the X-ray film cassette 7 is formed. ,
Plane tomographic plane of upper and lower jaw to be imaged, here FIG.
Is turned so as to intersect perpendicularly with the plane tomographic plane L3 shown in FIG. At this time, the position of the support arm 4 in the longitudinal direction of the support arm 4 with respect to the patient's head is adjusted to an appropriate position by the XY table 2.

When the longitudinal direction of the support arm 4 is set perpendicular to the plane tomographic plane L3 to be photographed, X
The motor 8a is driven at the same time that the irradiation of the X-ray flux by the radiation source 6 is started. When the motor 8a is driven, the support arm 4 is linearly moved with respect to the base 1 in a direction perpendicular to the longitudinal direction of the support arm 4, and accordingly, the X-ray source 6 is also moved. Further, the drive of the motor 8a is transmitted to the moving screw shaft 7c by the belt mechanism 7b.
The linear film cassette 7 and the holder 7g are moved relative to the support arm 4 in a direction opposite to the direction in which the support arm 4 is moved. With the movement of the X-ray source 6 and the X-ray film cassette 7, the direction of the X-ray source 6
By (a), the X-ray bundle to be irradiated is rotated so as to be irradiated in the direction of the same position of the X-ray film cassette 7.
When the X-ray source 6 and the X-ray film cassette 7 have been moved by a predetermined section, the plane tomography ends.

FIG. 9 is a diagram showing the operation of the X-ray source 6 and the X-ray film cassette 7 during planar tomography. The plane tomography by the plane tomography apparatus 51 is performed as follows. Here, a case is described in which the plane in the front-rear direction at the center of the front teeth, that is, the plane tomographic plane L11 in FIG. 7 is set as the plane tomographic plane L to be imaged. In FIG. 9, the subject P is the patient's head. First, the patient is seated on a chair (not shown), and the head is fixed between the X-ray source 6 and the X-ray film cassette 7. And
The position of the support arm 4 in the horizontal plane is adjusted by the XY table 2 and the orientation is adjusted by the turning mechanism 3 so that the longitudinal direction of the support arm 4 coincides with the center line AA orthogonal to the plane tomographic plane L. .

Here, since the direction of movement of the support arm 4 must be parallel to the plane tomographic plane L, the adjustment of the angle of the support arm 4 is particularly important.
This adjustment is easy because the patient does not need to be oriented in a specific direction.

The magnification of the so-called X-ray image is determined by the ratio of the distance D1 from the X-ray source 6 to the X-ray film cassette 7 and the distance D2 from the X-ray source 6 to the plane tomographic plane L.
The position of the support arm 4 may be set so as to obtain a desired magnification.

In imaging, the X-ray source 6 moves from a position indicated by a solid line slightly away from the center line AA to a target position indicated by a broken line beyond the center line AA as indicated by an arrow I. The support arm 4 is linearly moved by the linear slide mechanism 8 so as to perform the operation. In conjunction with this, the X-ray film cassette 7 is moved in parallel in the opposite direction from the position of the solid line to the position of the broken line as indicated by the arrow J, and the X-ray flux emitted from the X-ray source 6 according to this movement. The X-ray source 6 is rotated such that the center of the X-ray always passes through the center point C of the plane tomographic plane L and enters the same position of the X-ray film cassette 7.

As a result, the image of the same portion of the plane tomographic plane L is always incident on the film in the X-ray film cassette 7 at the same position, whereas the image of the part other than the plane tomographic plane L is imaged on the film surface. Is moved to a blurred image, and an X-ray image N of the plane tomographic plane L is captured. In order to obtain a clear X-ray image, it is desirable that the moving amount is large. Also, the movement range does not necessarily need to be contrasted with respect to the center line AA.

The shape of the irradiation field of the X-ray source 6 and the shape of the light receiving of the X-ray film cassette 7 are determined by the irradiation field shape switching plate 6b driven by the motor 6c and the switching plate 7h. And the size is automatically switched.

Each time one plane tomography is completed, the motor 7f is driven at a predetermined pitch, and the holder 7g and the X-ray film cassette 7 are moved with respect to the housing 7d, thereby forming one X-ray film. A plurality of plane tomographic images can be taken at the same time.

Accordingly, since the X-ray film cassette 7 used for the curved tomography is provided with the photosensitive pattern 81b for exposing the positional information, the positional information is exposed to the recorded curved tomographic image. In addition, it is possible to eliminate the displacement between the curved tomographic image recorded on the X-ray film and the scale provided on the sharkstain, which is caused by the above-described conventional technique. In addition, since positional information is exposed on the curved tomographic image, the accuracy of the installation position when installing the X-ray film on the sharksten for aligning the position between the scale and the curved tomographic image as in the related art is low. Not required,
It is possible to improve the operability when the X-ray film is set on the sharks-ten. Further, there is no need for a dedicated sharksten provided with a scale as in the related art.

Also, since there is no shift between the curved tomographic image and the scale due to an installation error when the X-ray film is installed on the sharksten as in the prior art, the plane tomographic image to be photographed in the recorded curved tomographic image is not generated. One piece of position information 91 corresponding to the position, that is, the index 91d can be accurately selected. As a result, the plane tomography by the tomographic X-ray imaging apparatus 51 can be performed by the plane tomography corresponding to the accurately selected index 91d. Can be done about the surface.

Since the X-ray film is held by the X-ray film cassette 7 at the time of curved tomography,
The position information 91 exposed by the photosensitive pattern 81b can always be accurately exposed to the position where the curved tomographic image is to be exposed. As a result, for example, the position of the positional information in the curved tomographic image is deviated every time imaging is performed. Therefore, one index 91d to be always selected accurately can be selected.

FIG. 10 is a sectional view showing the structure of an X-ray film cassette 7a according to another embodiment of the present invention. FIG.
At 0, parts similar or corresponding to the X-ray film cassette 7 shown in FIGS. 1 and 6 are denoted by the same reference numerals. The feature of the X-ray film cassette 7a is that the position information 91 included in the curved tomographic image 97 in FIG. 8 described above is exposed to light emitted from the light emitting element 101.

The light emitting element 101 is constituted by, for example, a plurality of light emitting diodes arranged in a matrix. The light emitting element 101 configured as described above includes a cable 103
Is controlled by the control unit 104 via the. Light emitting element 1
01 is a light emitting element 101 in the X-ray film cassette 7a.
The X-ray shielding plate 102 made of a material such as lead is provided on the X-ray source 6 side of the light-emitting element 101 on the X-ray source 6 side of the X-ray film 96. Be provided.

As described above, the position information 91 contains the light emitting element 101.
The light emission pattern formed by the light emission of the light emitting element 101 can be freely changed by the control of the control unit 104, so that, for example, a change in the magnification of the curved tomographic image 97 or a patient who is the subject The position information 91 can be easily changed according to the difference between the adult and the child. At this time, the control unit 104
May be performed in conjunction with the control by the control unit 11 of the tomographic X-ray imaging apparatus 51 of the above-described embodiment.

In each of the above-described embodiments, the curved tomographic image and the planar tomographic image are recorded using the X-ray film 96. However, the X-ray image can be obtained by using a well-known X-ray image sensor as an X-ray recording medium. An X-ray camera comprising a fluorescent plate for converting X-rays into visible light and an SIT (Silicon Intensified tube) for converting an image on the fluorescent plate into an electric signal with high sensitivity, using a semiconductor device instead of the SIT An X-ray CCD (Charge Coupled Device) sensor, an X-ray fluorescence intensifier, and the like are used. At this time, the photosensitive pattern 8
1b or the light emitting element 101 is provided on the light receiving surface of the X-ray image sensor, on the fluorescent plate, or the like.

[0061]

As described above, according to the present invention, it is possible to eliminate the deviation between the curved tomographic image recorded on the X-ray detecting means and the scale provided on the Schaukasten, which has occurred in the above-mentioned prior art. . In addition, since positional information is exposed on the curved tomographic image, the accuracy of the installation position when the X-ray detecting means for aligning the position between the scale and the curved tomographic image as in the related art is installed on the Schaukasten is accurate. Is not required, so that it is possible to improve the operability when the X-ray detecting means is installed on the sharks-ten. Also, there is no need for a dedicated sharksten provided with a scale as in the conventional case.

Further, according to the present invention, it is possible to accurately select one piece of position information without causing a shift between a curved tomographic image and a scale as in the related art. The plane fault plane can be accurately determined. Thus, the imaging of the plane tomographic plane of the subject can be performed at the accurately determined position.

Further, according to the present invention, the position information can always be accurately exposed to the position where the curved tomographic image is to be exposed. As a result, for example, the position of the position information in the curved tomographic image is changed every time the image is taken. It is possible to always select one piece of position information to be accurately selected without deviation.

[Brief description of the drawings]

FIG. 1 is a tomographic X-ray imaging apparatus 51 according to an embodiment of the present invention.
FIG. 2 is a perspective view showing an internal structure of an X-ray film cassette 7 used for the present embodiment.

FIG. 2 is a partially cutaway side view showing a configuration of the tomographic X-ray imaging apparatus 51.

FIG. 3 is a partially cutaway perspective view showing a configuration of a tomographic X-ray imaging apparatus 51.

FIG. 4 is a partially broken perspective view showing a partial configuration of the tomographic X-ray imaging apparatus 51.

FIG. 5 is a block diagram showing an electrical configuration of a drive circuit of the tomographic X-ray imaging apparatus 51.

FIG. 6 is a cross-sectional view showing a configuration of the X-ray film cassette 7.

FIG. 7 is a view showing a plurality of predetermined plane tomographic planes L1 to L21 in the lower jaw 71.

8 is a front view of a curved tomographic image 97 of an upper jaw and a lower jaw having position information 91. FIG.

FIG. 9 is a diagram showing the operation of the X-ray source 6 and the X-ray film cassette 7 during planar tomography.

FIG. 10 is a sectional view showing a configuration of an X-ray film cassette 7a according to another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 base 2 XY table 2a, 2c, 3a, 6a, 6c, 7f, 7j, 8a motor 3 turning mechanism 4 support arm 6 X-ray source 7, 7a X-ray film cassette 8 linear slide mechanism 11, 104 control unit DESCRIPTION OF SYMBOLS 12 Control panel 13 X-ray generation circuit 21-28 Motor drive circuit 33-38 Sensor 39 Memory 71 Lower jaw 72 Dental arch 81 Cassette body 81b Photosensitive pattern 82 Lid 91 Position information 96 X-ray film 97 Curved tomographic image 101 Light emitting element L1 L21 plane fault plane

Continuation of the front page (72) Inventor Takahiro Yoshimura 680 Higashihama-minamicho, Fushimi-ku, Kyoto-shi, Kyoto, Japan Morita Manufacturing Co., Ltd. (56) References JP-A 7-111990 (JP, A) (58) .Cl. ⁷ , DB name) A61B 6/14

Claims (2)

(57) [Claims] An X-ray generator and X-ray detection means provided with a subject interposed therebetween, and an X-ray generator driving means for driving the X-ray generator to control the position of the X-ray generator; Driving means for driving the X-ray detecting means for controlling the position of the X-ray detecting means; position control data for each of one or more predetermined plane tomographic planes corresponding to the subject Data input means for selecting and inputting position information corresponding to the plane tomographic plane to be imaged, and storing the data in the position data storage means based on the position information input by the input means. In the tomographic X-ray apparatus for performing curved tomography and planar tomography by controlling the X-ray generator driving means and / or the X-ray detection means driving means in accordance with the position control data set forth above, The X-ray detecting means includes position information recording means for recording position information corresponding to the plane tomographic plane on a detection surface of the X-ray detecting means, and the input means based on the position information recorded on the detection surface. A tomographic X-ray apparatus, wherein a tomographic plane to be imaged is selected. 2. The apparatus according to claim 1, wherein said position information recording means holds an X-ray recording medium having a photosensitive surface, and a position facing said X-ray recording medium includes a position of one or more predetermined plane tomographic planes corresponding to a subject. The tomographic X-ray apparatus according to claim 1, wherein information is recorded on the X-ray recording medium.