JP2003175031A - Digital x-ray panoramic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital X-ray panoramic imaging apparatus in which an X-ray panoramic image can be obtained at low cost only by simply controlling an X-ray generator and a two-dimensional X-ray image sensor or the like while further effectively utilizing conventional techniques. <P>SOLUTION: While turning an turn arm 3 on which an X-ray generator 1 and a two-dimensional X-ray image sensor 2 are located while being confronted in the state of fixing a turning center to sandwich an object S, X-rays emitted by the X-ray generator 1 and transmitted through the object S are detected by the two-dimensional X-ray image sensor 2 and the X-ray panoramic image is obtained. In such a digital X-ray panoramic imaging apparatus, the X-ray generator 1 is provided with a primary slit means 1h capable of fluctuating an X-ray emission width B in the turning direction of the turn arm 1 during X-ray imaging and by this primary slit means 1h, X-rays are emitted while fluctuating the X-ray emission width B corresponding to the turning angle of the turn arm 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital X-ray panoramic radiographing apparatus for irradiating a subject with an X-ray beam in a rotary manner to obtain an X-ray panoramic image of the subject. More specifically, the X-ray generator and the two-dimensional X-ray image sensor are arranged so as to face each other. Digital X-ray panoramic radiographing apparatus for extracting the X-ray absorption coefficient distribution information of the subject as image information by processing the X-ray projection data of the subject arranged so as to be sandwiched between the X-ray generator and the two-dimensional X-ray image sensor Regarding

[0002]

2. Description of the Related Art A turning arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other is fixed in a turning center so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating with, the two-dimensional X-ray image sensor detects the X-rays emitted by the X-ray generator and transmitted through the subject, and the X-ray projection data of the subject is arithmetically processed to obtain the X-ray absorption coefficient distribution information of the subject. Many proposals have heretofore been made for a digital X-ray panoramic imaging apparatus that obtains an X-ray panoramic image of a subject by extracting it as image information.

FIG. 18 shows a method for photographing a dental arch by such a digital X-ray panoramic radiographing apparatus. This device has been proposed by the present applicant, and the details thereof are disclosed in Japanese Patent Laid-Open No. 2000-139902.

This digital X-ray panoramic radiographing apparatus uses a CT radiography principle, and as shown in the figure, the center of rotation 103a of the swivel arm 103 is moved to the panorama of the dental arch S, which is the subject during X-ray radiography. The primary slit 101a is fixed to the center of the irradiation circle Q without changing the width of the primary slit 101a according to the swivel angle of the swivel arm 3.
By moving the position of a, from the X-ray generator 101,
The X-ray beam 101 passes through this panoramic irradiation circle Q so as to be as perpendicular as possible to the dental arch formed by the tooth to be the irradiation site in order to eliminate the inability to read the image due to the overlapping imaging of the tooth.
a is irradiated, the X-ray transmission image at that time is detected by the two-dimensional X-ray image sensor 102, and an X-ray panoramic image is obtained based on the image.

In the X-ray panoramic image obtained in this way, the X-ray beam is made to substantially follow the shape of the dental arch while moving the turning center of the turning arm during X-ray photography. The image was clearer than the X-ray panoramic image obtained by the conventional film method obtained by irradiating at right angles.

This is because in this photographing method, the center of the panoramic irradiation circle Q is selected as the position for fixing the turning center 103a of the turning arm 103. This panoramic irradiation circle Q is the same as the virtual local region Q used in FIG. 6 of the above publication, and is formed by integrating the portions through which the X-ray beam of the conventional film method always passes. By fixing the turning center 103a here, the X-ray panoramic radiography can be most efficiently realized.

On the other hand, the X-ray panoramic radiographing apparatus disclosed in Japanese Examined Patent Publication No. 1-17371 discloses a conventional X-ray radiographing while moving the rotation center of the swivel arm along the shape of the dental arch during X-ray radiography. In a dental panoramic radiography using a line film, the width of the X-ray beam in the swivel direction is changed during X-ray radiography according to the swivel angle of the swivel arm by the means for varying the primary slit width. Although it was an X-ray panoramic imaging device that can obtain the combined tomographic depth, the conventional panoramic X
No CT imaging was possible with the X-ray equipment.

Further, Japanese Patent Laid-Open No. 2000-139902 discloses a panoramic radiographing apparatus which uses the principle of CT (Computed Tomography) without using an X-ray film, which reduces the X-ray exposure dose and is small in size. In order to be able to use the two-dimensional X-ray sensor, the position of the primary slit 101h is moved without changing the width of the primary slit 101h during X-ray imaging.

[0009]

DISCLOSURE OF THE INVENTION The present invention is proposed for the purpose of further improving such a prior art.
In addition to normal panoramic X-ray photography, multi-panoramic panoramic X-ray photography and CT photography can also be performed, and the rotation arm can be rotated like conventional film-type panoramic X-ray photography. A digital X that can obtain an X-ray panoramic image at low cost by simply controlling an X-ray generator or a two-dimensional X-ray image sensor without requiring a complicated mechanism for moving the center along the dental arch. An object is to provide a line panoramic image capturing apparatus.

[0010]

The basic structure of the photographing apparatus of the present invention is such that the center of rotation is such that an object is sandwiched between an X-ray generator and a two-dimensional X-ray image sensor, as defined in the premise thereof. X-ray irradiation is performed while rotating while being fixed during X-ray photography, X-rays transmitted through the subject are detected by the two-dimensional X-ray image sensor in this way, and X-ray projection data of this subject includes back projection. This is an X-ray CT imaging apparatus that obtains three-dimensional X-ray absorption coefficient distribution information by performing arithmetic processing.

The present invention has three advantages obtained by this X-ray CT imaging.
In a digital X-ray panoramic imaging apparatus that obtains a desired X-ray panoramic image from dimensional X-ray absorption coefficient distribution information, while maintaining its basic configuration, the X-ray irradiation width and the X-ray irradiation direction are maintained during irradiation. It is possible to obtain a clearer panoramic image with a deeper subject depth by changing the. Further, when the X-ray irradiation direction is changed, the sensor is moved so that the two-dimensional X-ray image sensor does not become large.

According to a first aspect of the present invention, there is provided a digital X-ray panoramic radiographing apparatus, wherein a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, is provided with the X-ray generator and the two-dimensional X-ray image sensor. X-rays emitted from the X-ray generator and transmitted through the object are detected by the two-dimensional X-ray image sensor while the object is being swung with the swivel center fixed so as to sandwich the object. A digital X-ray panoramic radiographing apparatus for obtaining an X-ray panoramic image by taking out three-dimensional X-ray absorption coefficient distribution information as image information by arithmetically processing the line projection data, wherein the X-ray generator swivels the swivel arm. A primary slit means for varying the X-ray irradiation width in a predetermined direction, and the primary slit means divides the X-ray irradiation width according to the turning angle of the turning arm during X-ray imaging. While it is changing, and performs X-ray irradiation.

In this photographing apparatus, the X-ray irradiation width of the X-ray generator, more accurately, the swirl direction of the swivel arm (tangential direction of this swirl circle) is determined by the primary slit means in accordance with the swivel angle of the swivel arm. The X-ray irradiation is performed while changing the X-ray irradiation width of X.
By changing the line irradiation width, it is possible to change the tomographic thickness of a panoramic projection image of a subject that can be clearly photographed. Furthermore, it is possible to reconstruct a multi-slice panoramic image using the captured data after capturing. This makes it possible to obtain a clearer image by superimposing panoramic images with thin tomographic thicknesses, or to obtain only an inner (lingual) panoramic tomographic image and an outer (cheek side) panoramic tomographic image.

Further, this photographing apparatus is disclosed in Japanese Patent Laid-Open No. 2000-1.
Since the slit width is sequentially changed, as compared with the case of changing the position of the primary slit without changing the width of the primary slit as in Japanese Patent No. 39902, it is possible to change the thickness of a slice to be clearly imaged.

According to a second aspect of the present invention, there is provided a digital X-ray panoramic radiographing apparatus in which a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged so as to face each other, is provided with the X-ray generator and the two-dimensional X-ray image sensor. X-rays emitted from the X-ray generator and transmitted through the object are detected by the two-dimensional X-ray image sensor while the object is being swung with the swivel center fixed so as to sandwich the object. A digital X-ray panoramic radiographing apparatus for calculating a three-dimensional X-ray absorption coefficient distribution information as image information to obtain an X-ray panoramic image, wherein the X-ray generator is an X-ray generator.
An irradiation direction rotation means is provided for changing the radiation direction of the radiation relative to the swivel arm, and the irradiation direction rotation means corresponds to the swivel angle of the swivel arm during X-ray imaging. It is characterized in that the X-ray irradiation is performed while sequentially changing the direction of the ray irradiation.

Here, the irradiation direction rotating means is such that the X-ray generator is rotatably supported by the revolving arm, and the supporting angle of this rotation is changed to change the X-ray irradiation direction during X-ray imaging. The structure is relatively rotated, and is not changed by the primary slits provided in the X-ray generator. Therefore, a mechanism for adjusting the width of the primary slits is not required and the structure is simplified.

This photographing apparatus irradiates X-rays while changing the X-ray irradiation direction in accordance with the turning angle of the turning arm by means of the irradiation direction rotating means. It is possible to exhibit the same effect as that of the Japanese Patent Laid-Open No. 2000-139902.

In a digital X-ray panoramic radiographing apparatus according to a third aspect of the present invention, a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are opposed to each other is provided, and the X-ray generator and the two-dimensional X-ray image sensor are arranged. X-rays emitted from the X-ray generator and transmitted through the object are detected by the two-dimensional X-ray image sensor while the object is being swung with the swivel center fixed so as to sandwich the object. A digital X-ray panoramic radiographing apparatus, which obtains an X-ray panoramic image by taking out three-dimensional X-ray absorption coefficient distribution information as image information by processing the line projection data, wherein the two-dimensional X-ray image sensor is The three-dimensional X-ray image sensor is provided with sensor moving means capable of moving the position of the turning arm with respect to the turning arm in a direction perpendicular to the X-ray irradiation direction. X-ray irradiation is performed by the sensor moving means while sequentially moving the two-dimensional X-ray image sensor during X-ray imaging so as to receive X-rays that have passed through the subject in correspondence with the turning angle of the turning arm. It is characterized by

In this photographing apparatus, the sensor moving means irradiates the X-rays while sequentially moving the two-dimensional X-ray image sensor so as to receive the X-rays transmitted through the object according to the turning angle of the turning arm. , That is, two-dimensional X
Since the X-ray image sensor is made to follow X-ray irradiation (X-ray beam), it is possible to correspond to the imaging of an irradiation field larger than the size of the sensor, so it is possible to use a small X-ray sensor without using an expensive large X-ray sensor. Since the large irradiation field can be photographed, the sensor can be downsized.

According to a fourth aspect of the digital X-ray panoramic imaging apparatus of the present invention, there is provided a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, and the X-ray generator and the two-dimensional X-ray image sensor are arranged. The X-rays emitted by the X-ray generator and transmitted through the object are rotated while the object is sandwiched by and while the center of rotation is fixed.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator includes a primary slit unit capable of varying an X-ray irradiation width in a swiveling direction of the swivel arm, and an irradiation direction rotating unit capable of varying an X-ray irradiation direction relative to the swivel arm. Corresponding to the turning angle of the turning arm, the X-ray irradiation width is sequentially changed during X-ray imaging by the primary slit means, and the X-ray irradiation direction is changed by the irradiation direction turning means. It is characterized in that X-ray irradiation is performed while sequentially varying.

Since this photographing device is provided with both the primary slit means of claim 1 and the irradiation direction rotating means of claim 2, the effects of both are synergistically exhibited.

In a digital X-ray panoramic radiographing apparatus according to a fifth aspect of the present invention, a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, is provided with the X-ray generator and the two-dimensional X-ray image sensor. X-rays emitted from the X-ray generator and transmitted through the object are detected by the two-dimensional X-ray image sensor while the object is being swung with the swivel center fixed so as to sandwich the object. A digital X-ray panoramic radiographing apparatus for obtaining an X-ray panoramic image by taking out three-dimensional X-ray absorption coefficient distribution information as image information by arithmetically processing the line projection data, wherein the X-ray generator swivels the swivel arm. The two-dimensional X-ray image, comprising primary slit means capable of varying the X-ray irradiation width in a predetermined direction and irradiation direction rotating means capable of varying the X-ray irradiation direction relative to the swivel arm. The sensor includes a sensor moving unit that can move the position of the turning arm of the two-dimensional X-ray image sensor in the turning direction with respect to the turning arm in a direction perpendicular to the X-ray irradiation direction. Corresponding to the angle, the primary slit means sequentially changes the X-ray irradiation width during X-ray imaging, and the irradiation direction rotating means sequentially changes the X-ray irradiation direction to perform X-ray irradiation. The two-dimensional X-ray image sensor is sequentially moved by the sensor moving means so as to receive the X-ray transmitted through the subject.

Since this photographing apparatus is provided with the primary slit means of claim 1, the irradiation direction rotating means of claim 2 and the sensor moving means of claim 3, the effects of these three are synergistically achieved. Demonstrate.

In a digital X-ray panoramic radiographing apparatus according to a sixth aspect of the present invention, a swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, is provided with the X-ray generator and the two-dimensional X-ray image sensor. X-rays emitted from the X-ray generator and transmitted through the object are detected by the two-dimensional X-ray image sensor while the object is being swung with the swivel center fixed so as to sandwich the object. A digital X-ray panoramic radiographing apparatus for calculating a three-dimensional X-ray absorption coefficient distribution information as image information to obtain an X-ray panoramic image, wherein the X-ray generator is an X-ray generator.
The two-dimensional X is provided with irradiation direction rotating means capable of changing the irradiation direction of the rays relative to the swivel arm.
The line image sensor includes a sensor moving unit capable of moving a position of the turning arm with respect to the turning arm of the two-dimensional X-ray image sensor in a turning direction in a direction perpendicular to the X-ray irradiation direction. According to the turning angle of the turning arm, by the irradiation direction turning means,
X-ray irradiation is performed while sequentially changing the X-ray irradiation direction, and the two-dimensional X-ray image sensor is sequentially moved by the sensor moving means so as to receive X-rays that have passed through the subject. And

Since this photographing device is provided with both the irradiation direction rotating means according to claim 2 and the sensor moving means according to claim 3, the effects of both of them are synergistically exhibited. Claim 7
The digital X-ray panoramic radiographing apparatus according to any one of claims 1 to 6, wherein the two-dimensional X-ray image sensor is CdTe.
Element, CdZnTe element, MOS element, CMOS element,
It is characterized by being provided with an image pickup device using either an FT type CCD or an FFT type CCD.

In this photographing apparatus, since the type of the image pickup device which constitutes the two-dimensional X-ray image sensor is specifically defined,
It is possible to more easily configure an imaging device that exhibits the above effects. Moreover, when a CdTe element, a CdZnTe element, or the like capable of high-speed image processing is used as the image pickup element, an X-ray image can be handled as a moving image, and an image useful for medical examination can be provided.

A digital X-ray panoramic radiographing apparatus according to an eighth aspect is the digital apparatus according to any one of the first to seventh aspects, in which the swivel arm is provided between the X-ray generator and the swivel center. At least one of primary distance varying means capable of variably setting a primary distance and secondary distance varying means capable of variably setting a secondary distance between the two-dimensional X-ray image sensor and the turning center, It is characterized in that X-ray imaging can be performed in a state where at least one of the primary distance and the secondary distance is set to a desired value.

This photographing apparatus is provided with a primary distance varying means, and the distance between the X-ray generator and the turning center, that is, the X-rays emitted from the X-ray generator reaches the object set at the turning center. It is possible to variably set the primary distance up to, and the secondary distance varying means is provided, and the distance from the turning center to the two-dimensional X-ray image sensor, that is, the X-ray transmitted through the object reaches the sensor. Since the next distance can be set variably, the magnification ratio, resolution, and shooting area of the image can be changed by changing the primary distance and the secondary distance. As a result, the magnification ratio and resolution according to the shooting purpose can be changed. It becomes possible to shoot the shooting area.

A digital X-ray panoramic radiographing apparatus according to a ninth aspect is the digital X-ray panoramic apparatus according to any one of the first to eighth aspects, in which a turning center moving means for horizontally moving a turning center of the turning arm is provided. A position for dividing the imaged region of the subject by a predetermined ratio by using at least one of the subject moving means for moving the subject, and the distance between the X-ray generator and the two-dimensional X-ray image sensor. In the state where the position is fixed as described above, X-ray irradiation is performed on the imaging region within a predetermined swivel angle range, and of the three-dimensional X-ray absorption coefficient distribution information thus obtained, only the information within the swivel angle range is image information. Is obtained to obtain an X-ray panoramic image.

In this photographing apparatus, the turning center of the turning arm is not fixed to the center of the panoramic irradiation circle which is conventionally set when a panoramic image is obtained by using X-ray CT imaging. Positioning is fixed so that the imaging region, which is a part of the subject, is located at a position that divides the distance between the X-ray generator and the two-dimensional X-ray image sensor by a predetermined ratio, and this predetermined ratio is substantially maintained. This imaging region is irradiated with X-rays only within a predetermined turning angle range. Of the three-dimensional X-ray absorption coefficient distribution information thus obtained, only the above-mentioned turning angle range is extracted as image information, and this imaging region is extracted. The X-ray panoramic image of is obtained.

This imaging principle is hidden in the conventional method of obtaining a panoramic image by X-ray CT imaging described with reference to FIG. 18 "For a predetermined imaging region, an X-ray transmission image which is almost directly transmitted through this imaging region. From the fact that the panoramic image of this imaging region is constructed using the three-dimensional X-ray absorption coefficient distribution information obtained by inverse projection using the data, "the range of this irradiation angle is limited. Therefore, it is not always necessary to fix the turning center at a predetermined position in the related art, and therefore, the imaging center intentionally sets the turning center of the turning arm so that the distance between the X-ray generator and the two-dimensional X-ray image sensor is large. By fixing the position so that it comes to the position where it is divided at a predetermined ratio, it is possible to freely manipulate the enlargement ratio and resolution of the obtained panoramic image. " .

Therefore, according to this imaging apparatus, while using X-ray CT imaging, in addition to CT images, X-ray panoramic images similar to the conventional ones can be obtained, and the enlargement ratio and resolution can be freely set. Therefore, the imaging range of the digital X-ray panoramic imaging apparatus of the present invention can be greatly expanded.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram of an imaging method in an example of the digital X-ray panoramic imaging apparatus of the present invention.

In this figure, 1 is an X-ray generator, 2 is a two-dimensional X-ray image sensor, and these are arranged to face a swivel arm 3 which will be described later with reference to FIGS. In addition,
Here, the swivel arm 3 is expressed as a center line (dashed line) connecting the centers of the X-ray generator 1 and the two-dimensional X-ray image sensor 2, and the swivel center 3a of the swivel arm is
It is on this center line 3.

The X-ray generator 1 is provided with a primary slit means 1h capable of varying the X-ray irradiation width B in the turning direction of the turning arm 3 (the tangential direction of the turning circle).
The two-dimensional X-ray image sensor 2 is an X-ray beam 1a that is emitted from the X-ray generator 1 and that has passed through the dental arch S that is the subject.
The X-ray irradiation width B of the swivel arm 3 of the
Is provided with a secondary slit means 2a for limiting near the surface.

In this radiographing method, as in the radiographing method shown in FIG. 18, the X-ray beam 1a is swirling-irradiated while the swivel center 3a of the swivel arm 3 is fixed at a predetermined position of the dental arch S. At that time, for example, as shown in the drawing, a swivel angle [1] at which the X-ray beam 1a irradiates the tooth S8 that is a molar,
Rotation angle [2] for irradiating tooth S6, tooth S that is the front tooth
The X-ray irradiation width B is set to B [1], B [2], B [3] by the primary slitting means 1h in correspondence with the turning angle [3] for irradiating 1 and the turning angle of the turning arm 3. It is fluctuating.

It should be noted that, as described above, therefore, after the reference numerals, the respective parts which are changed by the turning of the turning arm 3 or whose turning positions are changed are added as necessary.
It will be shown in correspondence with each turning angle.

By doing so, the X-ray irradiation width B becomes smaller when irradiating the front tooth S1 than when irradiating the posterior tooth S8 or the like, and the X-ray image obtained in this way is a tomographic image. The depth is deeper and the front teeth S
An appropriate image can be obtained as one image, and a clearer X-ray panoramic image can be obtained as a whole. Furthermore, after imaging, the panoramic X-ray image of multiple slices can be reconstructed using the imaging data. This is capable of displaying an inner (lingual side) panoramic slice or an outer (cheek side) panoramic slice by image processing after photographing using photographing data.

Further, this photographing apparatus is disclosed in Japanese Patent Laid-Open No. 2000-1.
Since the slit width is sequentially changed, as compared with the case of changing the position of the primary slit without changing the width of the primary slit as in Japanese Patent No. 39902, it is possible to change the thickness of a slice to be clearly imaged. Furthermore, in addition to changing the slit position during photographing, the slit width is sequentially changed to exert a synergistic effect of both.

The tomographic thickness can be changed not only by the method of changing the slit width in advance as described above, but also by the arithmetic processing after imaging.

FIG. 2 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention. In this figure, (b) is an enlarged view of the X-ray generator 1 part in the state of the turning angle [2] in (a). From this,
The same parts as those already described are designated by the same reference numerals, and duplicate description will be omitted.

In this imaging method, the X-ray irradiation width B does not change as compared with the method of FIG. 1, and instead, the turning angle [1],
Corresponding to [2] and [3], the irradiation direction turning means described later in FIG. 11 causes the irradiation direction θ of the X-ray beam 1a, that is, the center line BC of the X-ray irradiation width B and the center line of the swivel arm. Three
(Here, the same reference numeral is used to indicate the turning arm and its center line.) The angle θ between the turning arm and the turning arm 3 is varied relative to the turning arm 3.

In the figure, reference numeral 1c of the X-ray generator 1 is the irradiation center of the X-ray generator 1, and the X-ray generator 1 is rotated about the irradiation center 1c.
By rotating with respect to
The irradiation direction of the line beam 1a is changed.

By doing so, similarly to the conventional example shown in FIG. 18, it is possible to obtain a transmission X-ray image in which the dental arch is irradiated as perpendicularly as possible, and the slit moves while fixing the rotation center. Without, it is possible to obtain an image similar to the conventional film-type X-ray panoramic image obtained by moving the rotation center. As a result, an image can be taken without using a mechanism for adjusting the width of the primary slit, so that the structure can be simplified.

FIG. 3 is an explanatory diagram of an image capturing method in another example of the digital X-ray panoramic image capturing apparatus of the present invention.

This imaging method changes the irradiation direction θ of the X-ray beam 1a according to the turning angles [1], [2], and [3] as in FIG. 2, but it corresponds to this. Then, the two-dimensional X-ray image sensor 2 is provided with the sensor moving means 2b,
Thereby, the position of the sensor 2 in the turning direction with respect to the turning arm 3 is moved so that the two-dimensional X-ray image sensor 2 follows the X-ray beam 1a in the irradiation direction θ.

In this way, the size of the two-dimensional X-ray image sensor 2 can be set to about the X-ray irradiation width B of the X-ray beam 1a, so that an image can be taken with an X-ray sensor smaller than the X-ray irradiation field. Therefore, it is not necessary to use an expensive large X-ray sensor. . Further, as the sensor 2 is downsized, the secondary slit means 2a can also be downsized, so that the device can be downsized and the cost can be reduced.

Further, as shown in the figure, the X-ray generator 1 and the two-dimensional X-ray image sensor 2 are installed on the swivel arm 3, but the sensor moving means 2b is perpendicular to the X-ray irradiation direction. Since it is moved in the direction, the two-dimensional X-ray image sensor 2 can always receive the X-ray beam 1a vertically and can detect the X-ray beam 1a more accurately. Although the sensor moving means 2b moves in the direction perpendicular to the X-ray irradiation direction and in the turning direction of the turning arm, the X-ray generator 1
It may be movable along an arc centered on the irradiation center 1c. The two-dimensional X-ray image sensor moving means 2
Specifically, b can be realized by a combination of a screw shaft and a motor or a combination of a timing belt and a motor.

FIG. 4 is an explanatory diagram of an image capturing method in another example of the digital X-ray panoramic image capturing apparatus of the present invention.

This photographing method is a combination of the photographing method of FIG. 1 and the photographing method of FIG. That is, while the X-ray irradiation width B is changed by the primary slit means 1h in accordance with the turning angles [1], [2], and [3], the X-ray beam 1a is turned by the irradiation direction turning means. The irradiation direction θ with respect to the arm 3 is varied, and the effects of both are synergistically exhibited.

FIG. 5 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

This photographing method is a combination of the photographing methods of FIG. 1, FIG. 2 and FIG. That is, while changing the X-ray irradiation width B by the primary slit means 1h in accordance with the turning angles [1], [2], and [3], the turning arm 3 of the X-ray beam 1a is turned by the irradiation direction turning means. The irradiation direction θ with respect to the sensor moving means 2b.
Allows the two-dimensional X-ray image sensor 2 to move the X-ray beam 1
It is moved so as to follow a, and the effects of these three are synergistically exhibited.

FIG. 6 is an explanatory diagram of an image capturing method in another example of the digital X-ray panoramic image capturing apparatus of the present invention.

This photographing method is the same as the photographing method of FIG.
It is a combination of the shooting methods. That is, the irradiation direction θ of the X-ray beam 1a with respect to the revolving arm 3 is simultaneously changed while changing the X-ray irradiation width B by the primary slit means 1h in accordance with the revolving angles [1], [2], and [3].
Is varied, and the effects of both are exhibited synergistically.

The primary slit means 1h here is shown in FIG.
As will be described later, two slit plates provided with predetermined slits (slit holes) are stacked before and after in the X-ray irradiation direction, and each slit plate is rotated in the swivel direction of the swivel arm, more specifically, the tangent line of this swirl circle. It is possible to move independently of each other in the direction so that the position can be adjusted. With the combination of these two slit plates, the above-mentioned X-ray irradiation width B and
The irradiation angle relative to the swivel arm 3 can be controlled independently.

FIG. 7 is an explanatory diagram of an image capturing method in another example of the digital X-ray panoramic image capturing apparatus of the present invention.

This photographing method is a combination of the photographing method of FIG. 6 and the photographing method of FIG. 3 in place of the photographing method of FIG. That is, the turning angle [1],
Corresponding to [2] and [3], while changing the irradiation direction of the X-ray beam 1a with respect to the swivel arm 3 by the primary slit means 1h, the two-dimensional X-ray image sensor 2 is operated by the sensor moving means 2b. The beam 1a is moved so as to follow the irradiation direction of the beam 1a, and both effects are synergistically exhibited.

FIG. 8 is an explanatory diagram of an image capturing method in another example of the digital X-ray panoramic image capturing apparatus of the present invention.

This photographing method is a combination of the photographing method of FIG. 6 and the photographing method of FIG. 3 in addition to the photographing method of FIG. That is, the turning angles [1], [2],
Corresponding to [3], the primary slit means 1h causes X
The X-ray beam 1a is simultaneously changed while varying the X-ray irradiation width B.
The irradiation direction of the rotating arm 3 is changed, and further, the two-dimensional X-ray image sensor 2 is moved by the sensor moving means 2b so as to follow the irradiation direction of the X-ray beam 1a. Exert synergistically. The configuration of the digital X-ray panoramic imaging apparatus that realizes the above-described imaging method will be described below.

FIG. 9 is a basic configuration diagram of an example of the digital X-ray panoramic imaging apparatus of the present invention.

This X-ray CT imaging apparatus 20 includes X-ray imaging means A, swivel arm drive control means C, arithmetic processing means D, display monitor E, object holding means 4, object position moving means 5, main frame 10, and operation. The unit 11 and the operation panel 10e are provided.

The X-ray photographing means A is composed of the above-mentioned turning arm 3
The revolving arm 3 has the X-ray generator 1 and the two-dimensional X-ray image sensor 2 suspended from each other.

The primary slit means 1h provided in the X-ray generator 1 adjusts an X-ray beam emitted from an X-ray tube (not shown) built in the X-ray generator 1 to obtain a desired beam. An X-ray beam 1a having a width can be emitted, the details of which will be described with reference to FIG.

The two-dimensional X-ray image sensor 2 has a CdTe element, a CdZnTe element, a MOS (Me
tal OXide Semiconductor) element, CMOS element, FT
-Type CCD, FFT-type CCD, X-ray fluorescence multiplier (XII)
It uses a camera or the like.

Particularly, a CdTe element or CdZnTe
Since the element is capable of high sensitivity and high-speed imaging, it is possible to transfer frame images of about 150 sheets / sec, and not only still images but also X-ray images of the subject can be reproduced and displayed as moving images. This makes it possible to provide a useful image, and exerts its effect in synergy with the effect of the present invention.

The FT type CCD is called a full transfer type CCD having a memory area in the CCD, and the FFT type CCD is called a full frame transfer type CCD in which the light receiving element itself of the CCD is used as a memory area. .

The swing arm 3 is provided with an XY table 31, a lift control motor 32, and a rotation control motor 33. By controlling the X-axis control motor 31a and the Y-axis control motor 31b, the rotation center 3a thereof is provided. Is adjustable in the XY directions, and is moved up and down by driving the elevation control motor 32. At the time of shooting, the rotation control motor 33 is driven at a constant speed so that the revolving arm 3 can revolve around the subject O. ing. The lifting control motor 32 constitutes an arm vertical position adjusting means of the turning arm 3.

Further, the center of rotation 3a of the revolving arm 3, that is, the revolving axis is provided vertically, the revolving arm 3 rotates horizontally, and the X-ray beam 1a is irradiated horizontally. It can be configured as a small vertical type.

This rotation control motor 33 is used for the turning arm 3
Of the swivel driving means, and a motor such as a servomotor whose rotational speed and rotational position can be freely controlled is used.
It is installed directly on the axis a.

Therefore, the revolving arm 3 can be rotated at a constant speed or at a variable speed, and its rotational position can be known along the time axis, so that the two-dimensional X-ray image sensor 2 can be timed. Therefore, it is convenient to take out an X-ray transmission image.

A hollow portion 3b is provided at the rotation center 3a of the swivel arm 3. In order to provide such a hollow portion 3b, it is necessary to provide hollow holes in all the related parts on the rotation center 3a. For example, the rotation control motor 33
As a result, a servomotor using a hollow shaft can be used for that purpose.

The hollow portion 3b connects a connecting line between the X-ray generator 1 and the two-dimensional X-ray image sensor 2 suspended from the swivel arm 3 and the operating portion 11 provided on the main frame 10 side. It is for placement.

When connecting the electric wiring to the rotating portion, the method of arranging the connecting line becomes a problem. When the connecting line is arranged through the rotation center 3a of the swivel arm 3 as described above, twisting due to rotation is caused. It is possible to minimize the influence of the above, and to obtain a preferable effect on the aesthetic appearance of the wiring.

In this embodiment, the swing arm drive control means C is constituted by combining the position adjusting means 31, which is an XY table, the elevation control motor 32, and the rotation control motor 33. Not limited. In the simplest structure, the center 3a of the revolving arm 3 may be set at an arbitrary position by operating a handwheel.

The subject holding means 4 comprises a chair 4b for holding the subject (patient) O in a sitting position, and a head fixing means 4a provided on the back of the chair 4b.

The subject position moving means 5 is provided with an X-axis control motor 51 for moving the subject holding means 4 to the left and right, a Y-axis control motor 52 for moving the subject holding means 4 back and forth, and a Z-axis control motor 53 for vertical movement means.

X driven by these motors 51-53
The axis, Y-axis, and Z-axis linear movement tables (not shown) are each composed of a well-known cross roller guide or a combination of ordinary bearings and guides, etc., and are capable of accurate linear movement. Further, for the movement of these X-axis, Y-axis, and Z-axis linear movement tables by the motors 51 to 53, a rack and pinion system, a ball screw system, a system using a normal screw shaft, etc. can be applied, but accurately What can be positioned is desirable.

In this way, the subject O is seated on the chair 4b,
The head of the subject O is fixedly held by the head fixing means 4a, and the rotation center 3a of the swivel arm 3 is held by using the subject moving means 5.
Then, a predetermined position of, for example, a dental arch inside the object O can be adjusted. On the other hand, instead of moving the subject fixing unit 4 by the subject moving unit 5, the XY table 31 and the elevation control motor 32 are used to move the revolving arm 3 side so that the rotation center 3a of the revolving arm 3 is moved to the dental arch. It is also possible to align the predetermined positions of.

In this device 20, both the object moving means 5 for moving the object side, the XY table 31 for moving the oscillating arm 3 on the irradiation side, and the lifting control motor 32 for the purpose of aligning the rotation center 3a. However, only one of them may be provided. In the case of X-ray CT imaging, it is important that the rotation center 3a does not shake.
Is preferably fixed.

In this way, the subject can be positioned appropriately for photographing while maintaining the natural posture of sitting on the chair, so that not only is the device gentle to the subject,
Secure patient fixation.

The arithmetic processing means D includes an arithmetic processor that operates at high speed for image processing analysis, and after the X-ray transmission image generated on the two-dimensional X-ray image sensor 2 is directly imaged or preprocessed. , The three-dimensional X-ray absorption coefficient data inside the object that has passed the X-rays is calculated by executing a predetermined calculation process, and the calculation such as the projection of this data on the projection surface is performed to display the means. E tomographic image,
The X-ray panoramic image is displayed and stored in a necessary storage medium as image information.

FIG. 10 shows the external appearance of the digital X-ray panoramic radiographing apparatus shown in FIG. 9. FIG.
(B) is the side view.

The X-ray CT imaging apparatus 20 is constructed by using the main frame 10 which is a portal type structure having extremely high rigidity as a whole supporting body.

This main frame 10 includes X-ray generators 1 and 2
An arm 10a that rotatably supports a revolving arm 3 that is hung and arranged so as to face the three-dimensional X-ray imaging means 2, a pair of lateral beams 10b that fixedly holds the base end portion of the arm 10a, and this lateral beam. A pair of vertical beams 10c supporting the beam 10b and a pair of vertical beams 10c are fixedly mounted,
It is composed of a base 10d which is the basis of the entire apparatus 20.

Each of the members constituting the main frame 10 is made of a steel material having high rigidity. Further, braces and corner reinforcing members are appropriately provided to resist deformation, so The rotation center 3a of the swivel arm 3 does not change.

Since the main frame 10 is thus structured so that the swinging swing of the swinging arm 3 does not occur,
In particular, it is suitable as an X-ray CT imaging apparatus that is required to have no swing shake.

The operation panel 10e is provided on the surface of one of the vertical beams 10c of the main frame 10 at a position where the operator can easily operate it in a standing position. The chair 4b of the subject holding means 4 is mounted on the subject position moving means 5 described in FIG. 9, and the chair 4b is moved in the X, Y, and Z directions, that is, the front-rear, left-right, and up-down directions. Further, the back plate 4ba of the chair 4b can be tilted to tilt and hold the head of the subject O.

With such a configuration, this digital X-ray panoramic radiographing apparatus can take not only normal panoramic radiographing but also multi-tomographic panoramic X-ray radiographing and also CT radiographing.

FIG. 11 (a) is a plan view showing an example of the irradiation direction rotating means of the present invention, and FIG. 11 (b) is a vertical sectional view of the X-ray generator portion. It shows a wire generator mounting portion.

FIG. 11A shows the irradiation direction rotating means 34 as seen from above, and the rotating means 34 is X-shaped.
A servo motor 34a that drives the entire wire generator 1 so that it can be angularly positioned, a worm gear 34b that is rotationally driven by this motor 34a, a worm wheel 34c that meshes with the worm gear 34b, and a base 34d that mounts these.
It consists of

The worm wheel 34c is engaged with the support shaft 1c supporting the entire X-ray generator 1 with respect to the swivel arm 3, and the irradiation direction rotating means 34 is provided with the X-ray generator 1. Can be rotated so that it can be angularly positioned,
Thereby, the X-ray irradiation direction with respect to the revolving arm 3 is changed. The center of the indicator shaft 1c is
It is the center for rotating the X-ray generator 1, that is, the irradiation center.

As shown in FIG. 11B, the X-ray generator 1
Is an X-ray generation source 1A, a shielding box 1b that shields an X-ray beam generated from it so as to prevent unnecessary leakage, and a primary slit means 1 provided on the opening side of the shielding box 1b.
equipped with h. Further, the center of the X-ray generation source 1A and the center of the indicator shaft 1c need to coincide with each other. Otherwise, when the X-ray generator 1 is rotated by the irradiation direction rotating means 34, the X-ray generation source 1A causes eccentricity and the X-ray beam is not irradiated in the correct direction.

The primary slit means 1h has a structure for slidably supporting two kinds of slit portions 1e, 1f having slits of a predetermined shape formed by the supporting mechanism 1d, and the slit portions 1e, 1f are independent of each other. , Equipped with a drive mechanism capable of positioning, slit portions 1e of both of these,
By combining the slits of 1f, a desired slit shape can be selectively formed, a desired X-ray irradiation width can be realized, and, like the irradiation direction rotating means 34, the X-direction for the revolving arm 3 can be increased. It is also possible to change the line irradiation direction.

FIG. 12A is an external perspective view showing the primary slit means, and FIG. 12B is a conceptual view of the slit plate of FIG.

As can be seen from FIG. 12, the support mechanism 1d
Is provided with a support plate 1da and two sets of four guide rollers 1db and 1dc provided on the support plate 1da. The guide roller 1db slidably supports the slit portion 1e, and the guide roller 1dc slidably supports the slit portion 1f.

The slit portion 1e is a guide frame 1ea guided by the guide roller 1db, and the slits 1ec and 1e of a predetermined shape are exchangeably fitted into the guide frame 1ea.
slit plate 1eb provided with c ', and this slit plate 1eb
Drive plate 1ed that gives a sliding force to this drive plate 1ed
In addition, a servo motor 1ef is provided which gives a rotational driving force so that it can be positioned through a female screw and a screw shaft.

A similar guide frame 1f is provided for the slit portion 1f.
a, a slit plate 1fb having slits 1fc and 1fc 'of a predetermined shape, a drive plate 1fd, a screw shaft 1fe, and a servo motor 1ff. Two types of servo motor 1e
f and 1ff are supported by the support plate 1da, and the support plate 1da is attached to the opening of the shielding box 1b.
The primary slit means 1h regulates the X-ray beam emitted from the X-ray generation source 1A through the opening.

The slit plates 1eb and 1fb are the shielding box 1b.
Similarly to the above, it is made of an X-ray shielding metal such as lead or a lead-based alloy. In addition, 1g is X made of brass or tin
It is a line semi-transparent soft tissue resolution filter, and when a transmission image such as soft tissue having a high X-ray transmittance is particularly required,
It is used to reduce the energy of the X-ray beam emitted from the X-ray generator 1. It is desirable that the side edge of the filter 1g is processed into a concave curve and that the thickness is gradually reduced toward the curved edge.

According to such a primary slit means h which can be used for various purposes, for example, as shown in FIG. 12B, the relative positions of the slit 1ec 'of the slit plate 1eb and the slit 1fc' of the slit plate 1fb. The slit SL having a desired width can be formed by adjusting.

By moving both slit plates 1eb and 1fb at the same time while maintaining this relative position,
The X-ray irradiation direction can be changed while maintaining the X-ray irradiation width. Further, the X-ray irradiation direction can be changed while the X-ray irradiation width is changed by moving the both at the same time while changing the relative positions of the both.

FIG. 13 is a conceptual view showing another example of the primary slit means of the present invention.

The primary slit means 1i is composed of a horizontal direction limiting means 81, a vertical direction limiting means 82, and a total slit moving means 83.

The left-right direction restricting means 81 includes a pair of left-right slit plates 81a and 81b, female screws 81c and 81d provided on the respective slit plates 81a and 81b, a screw shaft 81e screwed to the female screws 81c and 81d, and this screw. It is composed of a left-right motor 81f that rotationally drives the shaft 81e. Female screw 81
Each of c and 81d is composed of a pair of female screws of a right screw and a left screw. Correspondingly, a male screw of a right screw and a left screw is also formed on the screw shaft 81e by allocating from the center in the longitudinal direction. Has been done.

Therefore, the left and right slit plates 81a and 81b are rotated by driving the left and right motor 81f.
By approaching or moving away from each other by the same distance to limit the width of the slit hole SL in the left-right direction to the center.

The vertical direction restricting means 82 includes a pair of upper and lower slit plates 82a and 82b, female screws 82c and 82d provided on the slit plates 82a and 82b, a screw shaft 82e screwed to the female screws 82c and 82d, and the screw. It is composed of a vertical motor 82f that rotationally drives the shaft 82e, and is arranged so as to be orthogonal to the left-right direction limiting means 81 as a whole. Each of the female screws 82c and 82d is composed of a pair of female screws of a right screw and a left screw. Correspondingly, the screw shaft 82e also has male screws of a right screw and a left screw, which are distributed from the center in the longitudinal direction. Are formed.

Therefore, by vertically driving the vertical motor 82f, the vertical slit plates 82a and 82b are formed.
By approaching or moving away from each other by the same distance to limit the width of the slit hole SL in the vertical direction to the central object.

In this way, the width of the slit hole SL, that is, the vertical and horizontal widths of the X-ray beam can be limited by the primary slit means 1i.

The all-slit moving means 83 is the plate 8 on which the horizontal direction limiting means 81 and the vertical direction limiting means 82 are placed.
3a, a moving guide 83b having a female screw for moving the entire plate 83a left and right, a moving guide 83b
Screw shaft 83c that fits into the female screw of
It comprises a bearing 83e that rotatably supports one end of c, and a motor 83d that rotatably supports the other end of the screw shaft 83c and applies a rotational driving force.

With this structure, the all-slit moving means 83 controls the rotation of the motor 83d so that the desired slit holes SL formed by the left-right direction limiting means 81 and the up-down direction limiting means 82 are moved in the left-right direction. That is, the swivel arm 3 can be moved in the swivel direction, more specifically, in the tangential direction of the swirl circle, and the direction of the X-ray beam formed by the slit hole SL is changed with respect to the swivel arm 3. be able to.

14A and 14B show an example of the sensor moving means of the present invention. FIG. 14A is a cross sectional view thereof, and FIG.
2 is a cross-sectional view taken along line X1 of FIG. 3, (c) is a cross-sectional view taken along line X2 of (a), and FIG.

The sensor moving means 2b comprises a moving guide body 2c, a moving body 2d, a timing belt 2e, two timing pulleys 2f, a plurality of guide rollers 2g and a servo motor 2h.

The moving guide main body 2c serves as a guide so that the moving guide main body 2c moves in an arc along the moving guide main body 2c as a whole. It corresponds to the distance from the mounting position of the dimensional X-ray image sensor 2. The moving body 2d
The movement guide body 2c is fitted in the groove portion 2ca and slides along the arc.

The timing belt 2e is wound around the two timing pulleys 2f without any looseness in a state where the movement guide main body 2c is attached to a part of its endless ring, and gives a rotational driving force to either one of the pulleys 2f. By that,
The movement guide main body 2c reciprocates between these pulleys 2f.

The timing belt 2e and the timing pulley 2f are housed in the movement guide body 2c. The guide roller 2g guides the timing belt 2e so as to follow the arcuate shape of the moving guide body 2c as much as possible.

The servomotor 2h gives a rotational driving force to one timing pulley 2f.

With such a structure, by controlling the rotation of the servo motor 2h, the movement guide main body 2c can be moved along the arc of the radius R via the timing pulley 2f and the timing belt 2e. That is, the position of the two-dimensional X-ray image sensor 2 in the swivel direction with respect to the swivel arm 3, the position of the radius R of this figure in the direction of the circular arc about the X-ray generator 1, that is, the arc of the radius R of this figure. Can be moved along.

Since the sensor moving means 2b may be moved in a direction perpendicular to the X-ray irradiation direction, the two-dimensional X
Even if the movement guide body of the line image sensor is not formed in an arc shape as in this embodiment, the structure can be simplified by forming a flat plate shape so as to move in the direction perpendicular to the X-ray irradiation direction. I can.

FIG. 15 is an enlarged view of the swivel arm, which is a partially cutaway view showing an example of the primary distance varying means and the secondary distance varying means of the present invention.

As shown in this figure, a swivel arm 3 having an X-ray generator 1 and a two-dimensional X-ray image sensor 2 at both ends.
Performs the swivel shooting with the swivel center 3a fixed to the center of the imaging part of the object O. As the shooting conditions, the X-ray generator 1 (more accurately, the X-ray generator 1 is built-in. X
The primary distance varying means 1j that variably sets the primary distance L1 between the radiation source 1A) and the turning center 3a, and the secondary distance L2 between the turning center 3a and the two-dimensional X-ray image sensor 2 can be variably set. The secondary distance varying means 2j is provided.

In this example, the primary distance varying means 1j is provided between the generator mounting portion 3c of the swivel arm 3 and the generator main body 1m, and the drive motor 1j is provided on the side of the generator mounting portion 3c.
a, a screw bearing 1jb provided facing the drive motor 1ja, a drive motor 1ja and a screw bearing 1jb both ends of which are rotatably supported, and a screw shaft 1jc to which a rotational drive force is applied from the drive motor 1ja is fixed.

On the other hand, on the side of the generator main body 1m, a screw block 1j having a female screw threadably engaged with the screw shaft 1jc.
d is fixed. Further, the generator mounting portion 3c and the generator main body 1m can be slid with respect to each other by the linear slide means 1je.

With such a structure, the screw shaft 1jc is rotated by rotationally driving the drive motor 1ja composed of a servo motor or the like, whereby the screw shaft 1j is rotated.
The screw block 1jd that is screw-engaged with c can be slid so that the position can be accurately set, and the primary distance L1 can be variably set as shown in the figure.

On the other hand, the secondary distance varying means 2j has the same structure as the primary distance varying means 1j, is provided between the sensor side mounting portion 3d of the swivel arm 3 and the sensor body 2m, and is located on the sensor mounting portion 3d side. Includes a drive motor 2ja, a screw bearing 2jb provided facing the drive motor 2ja, and both ends thereof are rotatably supported by the drive motor 2ja and the screw bearing 2jb.
Screw shaft 2 to which rotational drive force is applied from drive motor 2ja
jc is fixed.

On the other hand, on the sensor main body 2m side, a screw block 2j having a female screw threadably engaged with the screw shaft 2jc.
d is fixed. Further, the sensor mounting portion 3d and the sensor body 2m can be slid on each other by the linear slide means 2je.

With such a structure, the screw shaft 2jc is rotated by rotationally driving the drive motor 2ja composed of a servo motor or the like, whereby the screw shaft 2j is rotated.
The screw block 2jd, which is screw-engaged with c, can be slid so that the position can be accurately set, and the secondary distance L2 can be variably set, as illustrated.

In this figure, L (= L1 + L
2) is an imaging distance L between the X-ray generator 1 and the two-dimensional X-ray image sensor 2.

When the primary distance varying means 1j and the secondary distance varying means 2j are provided, the primary distance L1 and the secondary distance L are provided.
Since 2 can be independently and variably set, for example, if the primary distance L1 is increased without changing the secondary distance L2, the object O can be relatively closer to the two-dimensional X-ray image sensor 2 having the same surface area. Therefore, although the enlargement ratio and the resolution decrease, a larger area of the object O can be photographed by the two-dimensional X-ray image sensor 2.

On the other hand, the primary distance L without changing the secondary distance L2
If only 1 is reduced, the object O is moved further away from the two-dimensional X-ray image sensor 2 having the same surface area, so that the two-dimensional X-ray image sensor 2 captures an image in which the details of the object O are enlarged. be able to. That is, the resolution can be improved.

Such adjustment of the resolution and the enlargement ratio can be made by changing only the secondary distance L2, or by making both the primary distance L1 and the secondary distance L2 variable. At this time, it is also possible to make the shooting distance L variable so as not to change, and it is also possible to make the shooting distance L variable so as to change.

To give a concrete example, the enlargement ratio = L (= L1 +
If L1) / L1 is defined, L1 = 3, L2 = 1, enlargement ratio = 4/3 = 1.3, L1 = 6, L2 = 1, enlargement ratio = 7/6 = 1.2, L1 = 3, L2 = 2, enlargement ratio = 5/3 = 1.7, L1 = 6, L2 = 2, enlargement ratio = 8/6 = 1.3, and the like, the primary distance L1 and the secondary distance L2. By changing, it is possible to realize various enlargement ratios, resolutions, and shooting areas.

Thus, according to the digital X-ray panoramic radiographing apparatus provided with the primary distance varying means 1j and the secondary distance varying means 2j, the basic hardware of the X-ray generator 1 and the two-dimensional X-ray image sensor 2 is used. The resolution, magnification, and shooting area of the obtained image can be adjusted without changing the configuration, and shooting with the magnification, resolution, and shooting area according to the shooting purpose can be performed.

FIGS. 16 (a) and 16 (b) are explanatory views of a photographing method in another example of the digital X-ray panoramic photographing apparatus of the present invention, and FIGS. 17 (a) and 17 (b) are digital X-ray panorama of the present invention. FIG. 9 is an explanatory diagram of a method of capturing an X-ray panoramic image by the image capturing apparatus. The imaging method of FIG. 17 is substantially the same as the imaging method of the conventional digital X-ray panoramic imaging apparatus of FIG. 18, and the turning center 3a is fixed to the center QC of the panoramic irradiation circle Q. .

In this photographing apparatus, instead of obtaining the entire X-ray panoramic image of the dental arch S which is the subject, the X-ray panorama of the photographing region which is a part of the subject, in this example, the tooth S1 which is the front tooth. For the purpose of obtaining an image, symbol L3 indicates the distance between the X-ray generator 1 and the imaged region S1, and symbol L4 indicates the distance between the imaged region S1 and the two-dimensional X-ray image sensor 2.

The distances L3 and L4 are the distance L in FIG.
1 and L2, in this case, the distances L3 and L4 are, strictly speaking, the turning angle of the turning arm 3, that is, the irradiation angle of the X-ray beam 1a to the imaging region S1.
As shown in this figure, the distances L3 'and L4' are changed as they change as (a) and (b), respectively, but within this range, the distance L3 is approximately equal to the distance L.
3'distance L4 = distance L4 'may be used, and the size of the obtained X-ray image does not change.

In this case, if an X-ray panoramic image of the imaged region S1 is to be obtained, as shown in FIG. 16, the turning center 3a is moved so that the turning center 3a is not necessarily the center QC of the panoramic irradiation circle. The distance L3 between the X-ray generator 1 and the imaging region S1 and the distance L4 between the imaging region S1 and the two-dimensional X-ray image sensor 2 are not fixed to FIG.
The rotation center 3a is fixed so as to have a predetermined ratio, which is different from the case where the panoramic image of 7 is obtained, and the X-ray beam 1a irradiates the imaging region S1 as shown in the figure. Then, of the three-dimensional X-ray absorption coefficient distribution information obtained by performing arithmetic processing including inverse projection from the data thus obtained, only the irradiation range is extracted as image information, and the dental arch is extracted. It is possible to obtain a good X-ray panoramic image by performing calculations so as to obtain an image in line with.

The position of the turning center 3a of the turning arm 3 with respect to the subject S is fixed by setting the position of the subject S using the subject position moving means 5 described with reference to FIGS. Alternatively, the XY table 31 including the X-axis control motor 31a and the Y-axis control motor 31b described with reference to FIG.
1 may be used to position and fix the turning center 3a, or both the object position moving means 5 and the turning center moving means 31 may be used to set the object S and the turning center 3a.
Both and may be moved to set the positions and fixed.

This principle is based on the method for obtaining an X-ray panoramic image, which has been conventionally used for obtaining an X-ray panoramic image, in FIG. It is possible to obtain an X-ray panoramic image of a desired magnification and resolution for this imaging region by changing the turning center 3a in advance as shown in FIG. 16 so that the ratio of the distances L3 and L4 becomes a desired ratio. I found that I could do it.

Therefore, according to this photographing apparatus, the irradiation angle range of the desired photographing region is limited (this limitation is substantially made even in the conventional film type X-ray panoramic image). .), While using X-ray CT imaging, in addition to CT images, X-ray panoramic images similar to the conventional ones can be obtained while freely setting the enlargement ratio and resolution. The imaging range of the X-ray panoramic imaging device can be greatly expanded.

In addition, this photographing method has hitherto been shown in FIG.
It can be used in combination with the photographing method described with reference to FIGS. 8 and 15, and in that case, a synergistic effect is exhibited.

[0141]

According to the digital X-ray panoramic radiographing apparatus of the first aspect, the X-ray irradiation width of the X-ray generator, more accurately, is determined by the primary slit means in accordance with the turning angle of the turning arm. The X-ray irradiation is performed while changing the X-ray irradiation width in the turning direction of the turning arm (the tangential direction of the turning circle). The X-ray irradiation width is changed to change the slice thickness to the turning angle, that is, the object. Since it can be changed according to the turning irradiation angle, by optimizing it, a good X-ray panoramic image can be obtained as in the case of the film type. Further, since the center of rotation is fixed, the structure can be simplified as compared with the conventional film type, so that the patient can be securely fixed. Moreover, panoramic X-ray imaging of multiple slices can be performed.

According to the digital X-ray panoramic radiographing apparatus of the second aspect, the X-ray irradiation is performed by the irradiation direction rotating means while changing the X-ray irradiation direction in accordance with the turning angle of the turning arm. However, the same effect as that of JP 2000-139902 A can be exhibited without using a primary slit. Further, since it is not necessary to control the width of the primary slit, the slit structure can be simplified.

According to the digital X-ray panoramic radiographing apparatus of the third aspect, the two-dimensional X-ray image sensor is configured so that the sensor moving means receives the X-ray transmitted through the object according to the turning angle of the turning arm. To irradiate X-rays while moving, that is, to make the two-dimensional X-ray image sensor follow X-ray irradiation (X-ray beam).
A large X-ray irradiation width can be obtained with this small sensor. As a result, it is possible to photograph a wide irradiation field with a small X-ray sensor without using an expensive large X-ray sensor.

According to the digital X-ray panoramic radiographing apparatus of the fourth aspect, since both the primary slit means of the first aspect and the irradiation direction rotating means of the second aspect are provided, the effects of both are synergistic. Exerts to the target.

According to the digital X-ray panoramic radiographing apparatus of the fifth aspect, the primary slit means of the first aspect, the irradiation direction rotating means of the second aspect, and the sensor moving means of the third aspect are provided. Therefore, these three effects are synergistically exerted.

According to the digital X-ray panoramic radiographing apparatus of the sixth aspect, since both the irradiation direction rotating means of the second aspect and the sensor moving means of the third aspect are provided, the effects of both are provided. Exhibit synergistically. According to the digital X-ray panoramic radiographing apparatus of claim 7, in addition to the effect of any one of claims 1 to 7, the type of the image pickup device forming the two-dimensional X-ray image sensor is specifically defined. It is possible to more easily configure an imaging device that exhibits the above effects. Further, as an image pickup element, C capable of high-speed image processing
dTe element, CdZnTe element, X-ray fluorescence multiplier (XI
I) When using a camera or the like, an X-ray image can be handled as a moving image, and a more useful image can be provided for medical examination.

According to the digital X-ray panoramic radiographing apparatus of the eighth aspect, in addition to the effect of any one of the first to seventh aspects, a primary distance varying means is provided and the distance between the X-ray generator and the turning center is increased. It is possible to variably set the distance, that is, the primary distance until the X-rays emitted from the X-ray generator reach the object set at the turning center, and the secondary distance changing means is provided to provide a two-dimensional distance from the turning center. The distance to the X-ray image sensor, that is, the secondary distance until the X-rays that have passed through the subject reach the sensor, can be variably set. Therefore, by changing the primary distance and the secondary distance, the image can be enlarged. rate,
You can change the resolution and the shooting area.
It is possible to shoot with a magnification, resolution, and shooting area according to the shooting purpose.

According to the digital X-ray panoramic radiographing apparatus of the ninth aspect, in addition to the effect of any one of the first to eighth aspects, a panoramic image of the turning center of the turning arm is conventionally obtained by using the X-ray CT imaging. In order not to fix it at the center of the panorama irradiation circle that has been set when obtaining, the imaging region, which is a part of the subject, intentionally sets the distance between the X-ray generator and the two-dimensional X-ray image sensor. The position is fixed so as to come to the position to be divided by the ratio, and the X-ray is irradiated to this imaging region only within a predetermined turning angle range such that this predetermined ratio is substantially maintained, and the three-dimensional X-ray thus obtained. Of the absorption coefficient distribution information, only the one in the turning angle range is taken out as image information to obtain an X-ray panoramic image of this imaging region. Therefore, a CT image of a desired imaging region can be obtained using X-ray CT imaging. In addition, an X-ray panoramic image similar to the conventional one can be obtained while freely setting the enlargement ratio and resolution, and the imaging range of the digital X-ray panoramic imaging apparatus of the present invention can be greatly expanded. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an imaging method in an example of a digital X-ray panoramic imaging apparatus of the present invention.

FIG. 2 is an explanatory view of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 3 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 4 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 5 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 6 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 7 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 8 is an explanatory diagram of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

FIG. 9 is a basic configuration diagram of an example of a digital X-ray panoramic imaging apparatus of the present invention.

10A and 10B are external views of the digital X-ray panoramic radiographing apparatus of FIG. 9, in which FIG. 10A is a front view thereof, and FIG. 10B is a side view thereof.

11A is a plan view showing an example of the irradiation direction rotating means of the present invention, and FIG. 11B is a vertical sectional view of an X-ray generator portion.

FIG. 12A is an external perspective view showing an example of the primary slit means of the present invention, and FIG. 12B is a conceptual view of the slit plate of FIG.

FIG. 13 is a conceptual diagram showing another example of the primary slit means of the present invention.

14A and 14B show an example of the sensor moving means of the present invention, in which FIG. 14A is a cross sectional view thereof, FIG. 14B is a sectional view taken along line X1 of FIG. 14A, and FIG. 14C is a sectional view taken along line X2 of FIG. (D) is X of (c)
3 cross section

FIG. 15 is an enlarged view of a swivel arm showing an example of a primary distance varying means and a secondary distance varying means of the present invention, with a partially cutaway view.

16 (a) and 16 (b) are explanatory views of an imaging method in another example of the digital X-ray panoramic imaging apparatus of the present invention.

17 (a) and 17 (b) are explanatory views of an X-ray panoramic image capturing method in the digital X-ray panoramic image capturing apparatus of the present invention.

FIG. 18 is an explanatory diagram of an imaging method in a conventional digital X-ray panoramic imaging apparatus.

[Explanation of symbols]

1 X-ray generator 1a X-ray (X-ray beam) 1h Primary slit means 1j Primary distance varying means 2 Two-dimensional X-ray image sensor (imaging device) 2b Sensor moving means 2j Secondary distance varying means 3 swivel arms 3a Center of rotation of swivel arm 31 Turning center moving means 34 Irradiation direction rotation means 5 Subject position moving means 10 main frame 20 Digital X-ray panoramic imager B X-ray irradiation width Q Panorama irradiation circle S dental arch θ irradiation angle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Yoshimura             680 Higashihamanancho, Fushimi-ku, Kyoto-shi, Kyoto             Morita Manufacturing Co., Ltd. F term (reference) 4C093 AA12 CA32 CA37 DA05 EA14                       EB17 EB22 EC15 EC28 EC29                       ED10 ED12 FA16 FA20 FA23                       FA55

Claims (9)

[Claims] 1. A swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are opposed to each other, and a swivel center is fixed so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator is provided with a primary slit means for changing the X-ray irradiation width of the swivel arm in the swivel direction, and the primary slit means corresponds to the swivel angle of the swivel arm during X-ray imaging. A digital X-ray panoramic radiographing apparatus, wherein X-ray irradiation is performed while sequentially changing the X-ray irradiation width. 2. A swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, and a swivel center is fixed so that a subject is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator includes an irradiation direction rotating means capable of changing the X-ray irradiation direction relative to the rotating arm, and the irradiation direction rotating means allows the rotating arm of the rotating arm to move during X-ray imaging. A digital X-ray panoramic radiographing apparatus, which performs X-ray irradiation while sequentially changing the X-ray irradiation direction according to a turning angle. 3. A swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, and a swivel center is fixed so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The two-dimensional X-ray image sensor includes a sensor moving unit capable of moving a position of the two-dimensional X-ray image sensor in the turning direction of the turning arm with respect to the turning arm in a direction perpendicular to the X-ray irradiation direction. X-rays are sequentially moved by the sensor moving means while sequentially moving the two-dimensional X-ray image sensor so as to receive X-rays transmitted through the subject in correspondence with the turning angle of the turning arm during X-ray imaging. A digital X-ray panoramic imaging device characterized by performing irradiation. 4. A swivel arm in which an X-ray generator and a two-dimensional X-ray image sensor are opposed to each other, and a swivel center is fixed so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator has a primary slit means capable of varying the X-ray irradiation width in the swivel direction of the swivel arm, and an irradiation direction rotation capable of varying the X-ray irradiation direction relative to the swivel arm. Means for varying the X-ray irradiation width during X-ray imaging by the primary slitting means in accordance with the turning angle of the turning arm, and the irradiation direction rotating means for changing the X-ray irradiation direction. A digital X-ray panoramic radiographing apparatus characterized in that X-ray irradiation is carried out while sequentially changing. 5. A revolving arm, in which an X-ray generator and a two-dimensional X-ray image sensor are arranged to face each other, has a revolving center fixed so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator has a primary slit means capable of varying the X-ray irradiation width in the swivel direction of the swivel arm, and an irradiation direction rotation capable of varying the X-ray irradiation direction relative to the swivel arm. The two-dimensional X-ray image sensor is configured to move a position of the two-dimensional X-ray image sensor in the turning direction of the turning arm with respect to the turning arm in a direction perpendicular to the X-ray irradiation direction. A sensor moving means capable of performing the above-mentioned, and the X-ray irradiation width is sequentially changed during X-ray imaging by the primary slitting means, corresponding to the turning angle of the turning arm, and Wherein the irradiation direction turning means performs X-ray irradiation while sequentially varying the X-ray irradiation direction, and,
X transmitted through the subject by the sensor moving means
A digital X-ray panoramic radiographing apparatus, wherein the two-dimensional X-ray image sensor is sequentially moved so as to receive a line. 6. A swivel arm, in which an X-ray generator and a two-dimensional X-ray image sensor are arranged opposite to each other, is fixed at a swivel center so that an object is sandwiched between the X-ray generator and the two-dimensional X-ray image sensor. While rotating in the state, the X-rays emitted by the X-ray generator and transmitted through the subject are transmitted to the two-dimensional X-ray.
A digital X-ray panoramic radiographing apparatus which obtains an X-ray panoramic image by detecting the X-ray projection data of the subject by calculating with a line image sensor and extracting three-dimensional X-ray absorption coefficient distribution information as image information. The X-ray generator includes an irradiation direction rotating means capable of changing an X-ray irradiation direction relative to the swivel arm, and the two-dimensional X-ray image sensor is the two-dimensional X-ray image sensor. A sensor moving unit that sequentially moves the position of the turning arm in the turning direction with respect to the turning arm in a direction perpendicular to the X-ray irradiation direction is provided, and the irradiation direction rotation is performed corresponding to the turning angle of the turning arm. The moving means performs X-ray irradiation while sequentially changing the X-ray irradiation direction during X-ray imaging, and the sensor moving means receives the X-rays that have passed through the subject. Digital X-ray panoramic imaging apparatus characterized by moving the urchin the two-dimensional X-ray image sensor sequentially. 7. The digital X-ray panoramic radiographing apparatus according to claim 1, wherein the two-dimensional X-ray image sensor is a CdTe element, a CdZnTe element, or an MO.
S element, CMOS element, FT type CCD, FFT type CC
A digital X-ray panoramic radiographing apparatus comprising an image pickup device using either a D or X-ray fluorescence intensifier (XII) camera. 8. The digital X-ray panoramic apparatus according to claim 1, wherein a primary distance between the X-ray generator and the pivot center is variably set on the pivot arm. At least one of a secondary distance varying means capable of variably setting a secondary distance between the two-dimensional X-ray image sensor and the turning center, and at least one of the primary distance and the secondary distance. A digital X-ray panoramic radiographing apparatus, characterized in that X-ray radiography can be performed in a state where any one of them is set to a desired value. 9. The digital X-ray panoramic apparatus according to claim 1, wherein at least one of a turning center moving means for horizontally moving a turning center of the turning arm and a subject moving means for moving the subject. Using one of them, the imaging region of the subject is fixed to the imaging region such that the distance between the X-ray generator and the two-dimensional X-ray image sensor is divided at a predetermined ratio. An X-ray panoramic image is obtained by performing X-ray irradiation within a predetermined turning angle range and extracting only the information about the turning angle range from the thus obtained three-dimensional X-ray absorption coefficient distribution information as image information. A digital X-ray panoramic imaging device.