JP2006042852A - Auxiliary tool for roentgenography, roentgenography method, and processing method for roentgenograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to grasp the form of a dental root and the form of a root canal differing according to individuals from a three-dimensional image and to surely treat the root canal by obtaining two roentgenographs performing roentgenography from left and right two directions by using an auxiliary tool for a roentgenography and by forming the three-dimensional image of the tooth by performing procession of the two obtained roentgenographs. <P>SOLUTION: In the auxiliary tool for the roentgenography having adaptor portions and supporting arms and a roentgenography holder, the roentgenography holder is equipped with the two adaptor portions arranged spaced apart in left and right two directions, and the distal ends of the two supporting arms respectively extended from the two adaptor portions are arranged by being supported to be secured rotatably and in an arbitrary angle relatively to the roentgenography holder, such that the angles formed by the two adaptors against the roentgenography holder can be adjusted in left and right directions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an X-ray imaging auxiliary tool, an X-ray imaging method, and an X-ray imaging image processing method. By performing X-ray photography, using the obtained two X-ray photography images, an approximate slice image of a cross section of a desired part is created, and a plurality of the slice images are superimposed to create a three-dimensional image. The present invention relates to an X-ray imaging auxiliary tool, an X-ray imaging method, and an X-ray imaging image processing method capable of not only knowing the curvature and form of a tube but also predicting a root canal that is so thin that the X-ray imaging image does not appear. .

The feature of endodontic treatment (root canal treatment) of the tooth is that the crown portion is a visible region, but there is an invisible region at the root canal end portion of the root portion even if a microscope is introduced. The supplementary means of the invisible region of the root canal are the pulpal cavity inside the tooth-morphological knowledge of the root canal system, the visualized X-ray image of the treated tooth, the sense transmitted from the root canal to the finger through the instrument- This includes muscle sense information and root canal length measurements. Based on these, root canal treatment is performed by comprehensively imaging a three-dimensional image of the original pulp cavity-root canal system.
2001 separate volume Quintessence Endontics

  Here, there are dental imaging and panoramic imaging as a visualized X-ray image of the treatment tooth, but since the obtained X-ray image is a two-dimensional image, the depth of the root canal and the curved shape are accurately determined. It was difficult to judge. In addition, in the case of generating a three-dimensional image using CT imaging, the current situation is that it is hardly used in endodontic therapy in terms of resolution, cost, and exposure.

  The success rate of prominent clinicians and endodontic treatments, especially root canal treatments, reported at home and abroad, is said to be 70% to 80%. It is said that endodontic treatment is difficult to look directly at the root canal, and it is said that it is a groping process, and the root canal is also varied, and it is more complicated not only by individual differences but also by age-related changes. This is because it takes a form.

  When performing dental or pancreatic treatments for pulpectomy or infected root canal treatment, since the two-dimensional image is used, it is possible to grasp information on the root of the root, but it is cheek-lingual (the width of the root and the curvature of the root). It is difficult to grasp information. Therefore, a reamer or a file is inserted directly into the root canal, and treatment is performed while searching for the direction of the root canal.

Obtaining root canal morphology information by CT imaging is one of useful means. However, in general, it is not frequently performed because of lack of information in terms of resolution, a large installation space, an expensive device, and an increased exposure dose.
Journal of Pediatric Dentistry 40 No.1: 171-176 2002

  In the medical treatment of root canal treatment (endodontic therapy) and infected root canal treatment as described above, dead pulp (blood vessels and nerves) / contamination in the root canal depending on the root and root canal bending direction. If the reamer file that cleans the dentin that has been removed or the inside of the root canal is enlarged and does not reach the apex, the root canal may be perforated by manipulation of the inappropriate reamer or file (breaking the root canal) Problems such as breakage in the root canal of reamers and files are considered. For example, various problems such as misalignment outside the root canal and perforation outside the root canal occur, and not only need to be re-treated, but depending on the inappropriate treatment, it may become impossible to treat.

  Therefore, if a three-dimensional image of the root portion of each tooth is obtained in advance as information that has the resolution of the X-ray imaging means, it becomes an effective information source when performing treatment for extraction of the pulp and infected root canal treatment, Not only is it easy to search for root canal shapes using the senses of the fingers, but also shortens the treatment time, prevents perforation of the root canal due to inappropriate reamers and file operations, and prevents breakage of the reamer or file within the root canal. Be expected.

  However, it is difficult to generate a three-dimensional image by the conventional dental imaging and pano-mala imaging methods, and there is a disadvantage that information that can be sufficiently used in dentistry such as a root canal depth and a curved shape cannot be obtained. In the case of CT imaging, there is a disadvantage that the apparatus becomes large.

The present invention relates to an adapter unit to which an X-ray irradiation unit of an X-ray source for generating X-rays is detachably mounted, a support arm extended from the adapter unit in the X-ray irradiation direction, An X-ray imaging auxiliary tool provided with an X-ray imaging holder that is detachably held in an X-ray imaging unit that is provided at a tip and detects X-rays irradiated from the X-ray irradiation unit and passed through the subject. The two adapter portions are provided so as to be spaced apart from each other in the left and right directions with respect to the X-ray imaging holder, and the two adapter portions can be adjusted in the left-right direction with respect to the X-ray imaging holder. It is characterized in that the tip ends of two support arms respectively extending from two adapter parts are provided so as to be rotatable and fixed at an arbitrary angle to the X-ray imaging holder. The directions of the two adapter parts are set with respect to the X-ray imaging means, that is, the rotation of the support arm with respect to the light receiving surface of the CCD sensor or the like.
According to the present invention, a subject is positioned between an X-ray source that generates X-rays and an X-ray imaging unit that detects X-rays emitted from an X-ray irradiation unit of the X-ray source, and the X-ray imaging is performed. X-ray imaging is performed by irradiating the subject with X-rays from the X-ray irradiating unit of the X-ray source from the left and right directions at an arbitrary X-ray incident angle with respect to the means, and performing X-ray imaging. A photographed image is obtained.
Furthermore, the present invention performs X-ray imaging by irradiating a subject with X-rays from an X-ray irradiation unit of an X-ray source from two directions on the left and right sides at an arbitrary X-ray incident angle with respect to the X-ray imaging means. An X-ray image obtained by performing X-ray imaging with an arbitrary X-ray incident angle from the right direction with respect to the imaging means is positioned on the left side, and an arbitrary X from the left direction with respect to the X-ray imaging means. X-ray image obtained by performing X-ray imaging with a line incident angle is positioned on the right side, and imaging for detecting the position information of the subject in each X-ray image positioned on the left and right Set the reference line. The reference line draws a straight line parallel to the Y axis on the right side of the screen in the X-ray image arranged on the left side, and draws a straight line on the left side of the screen in the X-ray image arranged on the right side. Then, the reference lines of the two images are overlapped with each other, an outline point having an arbitrary edge width is determined for the X-ray image obtained from the left and right directions, and an X-ray is obtained from the outline point having an arbitrary edge width A projection line is drawn in the direction of the incident angle, a closed curve figure inscribed in the projection line is created in the area surrounded by the drawn projection line, and the obtained closed curve figure is an outline point of an arbitrary edge width of the subject A circle or an ellipse is created as a closed curve figure inscribed in the projection line in an area surrounded by the projection line drawn from the outline point of the arbitrary marginal width. An approximate three-dimensional image of a subject is created by superimposing a plurality of obtained circles or ellipses.

In the present invention, two adapter parts are set apart from each other in the left and right directions with respect to the X-ray imaging holder by an X-ray imaging auxiliary tool, and a subject is positioned between the X-ray source and the X-ray imaging means. X-ray imaging is performed by irradiating the subject with X-rays from the X-ray irradiator of the X-ray source from the left and right directions at an arbitrary X-ray incident angle with respect to the X-ray imaging means, and X-ray imaging is performed. A radiograph is obtained.
An X-ray image obtained by X-ray imaging from the left and right directions at an arbitrary X-ray irradiation angle is obtained by adding an arbitrary X-ray irradiation angle from the right direction to the X-ray imaging means. An X-ray image obtained by performing X-ray imaging by positioning an X-ray image obtained by imaging on the left side and adding an arbitrary X-ray irradiation angle from the left direction to the X-ray imaging means. Positioned on the right side, the imaging reference lines for detecting the position information of the subject provided when performing X-ray imaging from an arbitrary angle direction on the left and right X-ray imaging images are overlapped and positioned on the left and right The X-ray image is arranged at the reference position.
After an X-ray image obtained from X-ray imaging in the left and right directions is arranged at the reference position, an arbitrary edge width (for example, one X-ray image) is obtained with respect to the X-ray image obtained from the two directions. Determine the outline point of the X-ray image of the tooth root that is the subject displayed in the captured image (width from one side edge to the other edge), and project the projection line from each arbitrary edge width outline point It is drawn in the X-ray incident angle direction. This is performed on the left and right X-ray images, and four projection lines are drawn from the two X-ray images, and a circle or a closed curve figure inscribed in the projection line in a region surrounded by the drawn projection lines Ellipse slice images are continuously created in the vertical direction of each X-ray imaging means. By superimposing the inscribed circles or inscribed ellipse slice images of the cross-sections of the obtained plurality of subjects, a three-dimensional image of the subject can be obtained.
As described above, the present invention captures two X-rays obtained by imaging the left and right directions at an arbitrary X-ray incidence angle with an X-ray imaging auxiliary tool for a tooth to be subjected to extraction or root canal treatment. By creating an approximate slice image of the cross-section of the desired site using the photographed image and performing a process of creating a three-dimensional image by superimposing a plurality of slice images, it is possible to know the curvature and form of the root canal In addition, it is possible to predict a root canal that is so thin that it cannot be seen in an X-ray image.

In this invention, X-ray imaging is performed from two directions on the tooth at an arbitrary X-ray incident angle, and an approximate slice image of a cross section of a desired site is created using the obtained two X-ray imaging images. By performing the process of creating a three-dimensional image by superimposing a plurality of slice images, not only can the curvature and morphology of the root canal be known, but also a root canal that is so thin that it cannot be seen in an X-ray image can be predicted. It can be done.
The reason is that the root canal is thin because the root canal is located in the center of the root, so if the root cross section can be extracted even if it cannot be extracted with the resolution of the X-ray image, the root canal can be extracted. The existence of root canals can be predicted.
Embodiments of the present invention will be described below with reference to the drawings.

  1 to 18 show an embodiment of the present invention. The present invention makes it possible to know the curvature and form of the root canal of a tooth as a subject, and to predict a root canal that is so thin that it cannot be seen in an X-ray image.

The tooth has a crown portion that can be directly viewed and a root portion that cannot be directly viewed. The pulp cavity is a cavity that is located at the center of the tooth, and is filled with a pulp, which is a soft tissue in which nerves and blood vessels have entered, in a space that roughly matches the outer shape of the tooth. Of these pulp cavities, the root is called the root canal.
・ Dental morphology;
Authors Mikio Shiratsu, Masao Nakamura, Kyuhei Furuhashi Linyi Dental Co., Ltd. Published July 1, 1968. New Dental Hygienist Textbook Anatomy, Histogenesis, Oral Anatomy 2nd Edition:
Authors Yoshinobu Ide, Shigeo Osato, Shigeru Kobayashi, Kazuhito Takahashi, Yoshihisa Toda, Yoshikazu Higashi, Toshihiko Yajima Ishiyaku Shuppan Publishing Co., Ltd. issued on January 10, 1997

  The dead pulp (blood vessels and nerves) and contaminated dentin in this root canal are removed with a cleanser, and the root canal is enlarged and cleaned using a reamer or file, and then disinfected with a drug. Is called root canal treatment (endodontic treatment). Thereafter, a rubber-like antiseptic material is tightly filled up to the apical hole according to the thickness and length of the root canal. This is called root canal filling.

  When performing root canal treatment (endodontic therapy), the biggest problem is that treatment cannot be performed by directly looking at the root canal. If the root canal is bent, or depending on the shape of the root canal, the reamer or file may not reach the apex, or the root canal may be perforated (breaking the root canal) by inappropriate reamer or file manipulation, A breakage in the root canal of the reamer or file can be considered.

  As a result, the dental pulp cannot be completely removed, or a space is created without preserving the antiseptic material up to the apical foramen (root canal filling), resulting in accumulation of white blood cells, bacteria and spoilage products, and lesions. And the bone (alveolar bone) melts.

  That is, grasping the form of the root canal is most important in performing root canal treatment (endodontic therapy). However, the form of the root canal varies from tooth type to tooth type, and has a more complicated form depending on individual differences and changes with aging, so it is difficult to perform complete treatment.

  Therefore, if the bending direction and shape of the root canal are clarified in advance before root canal treatment, the root canal treatment can be easily performed, and the above lesion can be formed, and the alveolar bone is melted. It becomes possible to avoid the problem of end.

  Here, it is known that morphological characteristics (cross-sectional shape) generally referred to for each tooth type of the root portion that cannot be directly viewed have the following characteristics.

• Maxillary anterior teeth (No. 1 to 3)… Circular • Mandibular anterior teeth (No. 1 to 3)… Oval shape • Maxillary premolars (Nos. 4 and 5)… Gourd shape • Mandibular premolars (No. 4 and 5) ... Round / maxillary molars (Nos. 6 and 7)
Mesial cheek side root ... gourd shape
Centrifugal cheek root ... round
Palate root ... round, mandibular molar (No. 6, No. 7)
Mesial root ... gourd shape
Centrifugal root: circular The above shape approximates histologically

  The root canal (the pulpal cavity of the root) is a cavity that is located in the center of the root and has a shape that substantially matches the external shape of the tooth. It is thought that there is.

  In conventional X-ray images, there are individual differences in the root canal shape, and it is difficult to grasp the bent state of the root canal.

  In view of this, the present invention makes it possible to reliably perform root canal treatment by knowing the curvature and form of the root canal from a three-dimensional image. Furthermore, depending on the curvature and form of the root canal, it may be impossible to treat, or a root canal that is so thin that it cannot be seen in an X-ray image may be predicted, and the present invention makes it possible to estimate this in advance. Is.

  In the present invention, as shown in FIGS. 1 to 2, an X-ray imaging image is acquired by using an X-ray imaging auxiliary tool 4 in the X-ray imaging apparatus 2. The X-ray imaging apparatus 2 includes an X-ray generator 6 that is an X-ray source that generates X-rays, and an X-ray that is irradiated from an X-ray irradiation unit 8 of the X-ray generator 6 and passes through a tooth Z that is a subject. And X-ray imaging means 10 for detecting.

  Examples of the X-ray imaging means 10 include a CCD sensor, a film, and an image sensor (TFT, MOS, CCD, XII, XICCD, FPD, IP, etc.) that is a two-dimensional X-ray image sensor. Any X-ray imaging means 10 may be used as long as it can reproduce an image. An image sensor that is a two-dimensional X-ray image sensor is an X-ray sensor that converts an X-ray image into an electrical signal instead of an X-ray film. In this embodiment, a CCD sensor will be exemplified and described as the X-ray imaging means 10.

  The X-ray imaging auxiliary tool 4 includes an adapter unit 12, a support arm 14, and an X-ray imaging holder 16. The adapter part 12 is formed in a ring shape, and is detachably mounted with an X-ray irradiation part 8 of an X-ray generator 6 constituting the X-ray imaging apparatus 2 used for dental imaging. The support arm 14 has a proximal end fixed to the adapter portion 12 and has a distal end extended from the adapter portion 12 in the X-ray irradiation direction. The X-ray imaging holder 16 is provided at the extended tip of the support arm 14 and is formed in a substantially L shape by the holding portion 18 and the support portion 20. The holding unit 18 is provided with a holding groove 22 that detachably holds the CCD sensor 10 that is an X-ray imaging unit constituting the X-ray imaging apparatus 2. A bite block 24 that is pressed against the tooth Z is fixed to the support portion 20. The bite block 24 is provided with a plurality of protruding protrusions 26 formed in parallel.

  The X-ray imaging auxiliary tool 4 is provided with two adapter portions 12-1 and 12-2 that are spaced apart from each other in the left and right directions with respect to the X-ray imaging holder 16. Stepped cutout portions 28-1 and 28-2 are formed at the tips of the two support arms 14-1 and 14-2 that are extended from the two adapter portions 12-1 and 12-2, respectively. ing. The cutout portion 28-1 of one support arm 14-1 is provided on the side facing the support portion 20 of the X-ray imaging holder 16. The cutout portion 28-2 of the other support arm 14-2 is provided on the side away from the support portion 20 so as to engage with the cutout portion 28-1. The two support arms 14-1 and 14-2 are provided with through holes 30-1 and 30-2 formed in the notches 28-1 and 28-2, and the through holes 30-1 and 30-2 are provided. The protrusions 32-1 and 32-2 are formed on the same radius centered at −2 and on the side facing the support portion 20.

  The support portion 20 of the X-ray imaging holder 16 is provided with a rotatable fastening means, for example, a screw hole 34, on the side facing the tips of the two support arms 14-1 and 14-2, A plurality of engagements in which the protrusions 32-1 and 32-2 are engaged with each other on the side opposite to the two support arms 14-1 and 14-2 on the same radius around the screw hole 34. The holes 36-1 and 36-2 are formed at equal intervals in the circumferential direction. The fixing of the support arms 14-1 and 14-2 is not limited to the screw hole 34.

  The two support arms 14-1 and 14-2 open at an arbitrary angle θ by matching the through holes 30-1 and 30-2 with the notches 28-1 and 28-2 coming into contact with each other. The parts 32-1 and 32-2 are engaged with arbitrary engaging holes 36-1 and 36-2 formed in the support part 20 of the X-ray imaging holder 16, and fixed to the through holes 30-1 and 30-2. By inserting the fixing screw 40 fitted with the screw 38 and screwing the fixing screw 40 into the screw hole 34 of the supporting portion 20, the fixing screw 40 is rotatably supported by the supporting portion 20 by the elastic force of the fixing spring 38. The projections 32-1 and 32-2 are fixed to an arbitrary angle θ by engagement with any one of the plurality of engagement holes 36-1 and 36-2.

  Thereby, the auxiliary tool 4 for X-ray imaging has two adapter parts 12-1 and 12-2 so that the angle of the two adapter parts 12-1 and 12-2 can be adjusted in the horizontal direction with respect to the X-ray imaging holder 16. The ends of the two support arms 14-1 and 14-2 respectively extended from 12-2 are supported and provided on the support portion 20 so as to be rotatable and fixed at an arbitrary angle θ.

  This X-ray imaging auxiliary tool 4 has an angle θ formed by the two support arms 14-1 and 14-2 with the fixing screw 40 at the tip as a rotation center P1, that is, an X-ray irradiation unit of the X-ray generator 6. The X-ray incident angle of the X-rays irradiated from the CCD sensor 10 with respect to the elastic force of the fixing spring 38 fitted to the fixing screw 40 of the rotation center P1, the projections 32-1 and 32-2 and the engaging hole It is an auxiliary tool that can be changed to an arbitrary angle by being engaged with 36-1 and 36-2, can be fixed at a set angle, and has a fixing method for holding the set angle separately. .

  The X-ray imaging auxiliary tool 4 positions a tooth Z, which is a subject, between an X-ray generator 6 that is an X-ray source and a CCD sensor 10 that is an X-ray imaging unit. The two adapter parts 12-1 and 12-2 are set apart from each other in the left and right directions with the fixing screw 40 at the tip as the turning center P1, and the two support arms 14-1 and 14-2 are turned at the tip. The angle θ formed with respect to the center P1 is set to an arbitrary angle, in this embodiment, 45 degrees from the CCD sensor surface. That is, X-ray imaging is performed by irradiating the tooth Z with X-rays from the X-ray irradiation unit 8 of the X-ray generator 6 from two directions of 45 degrees with respect to the CCD sensor 10 at an arbitrary X-ray incident angle. X-ray images from two left and right directions are obtained.

  The X-ray imaging auxiliary tool 4 can also be used as a normal X-ray imaging auxiliary tool by removing one of the two support arms 14-1 and 14-2.

  Further, as shown in FIG. 3, the auxiliary tool 4 for X-ray imaging can be provided with a substantially U-shaped auxiliary arm 42 in consideration of X-ray imaging of a molar or the like.

  The auxiliary arm 42 is provided with a screw hole 43 formed at one end thereof, and a support portion 44 is formed so as to surround the screw hole 43, and the support portion 44 has the same radius around the screw hole 43. A plurality of engagement holes 45-1 and 45-2 are formed to engage the protrusions 32-1 and 32-2 of the two support arms 14-1 and 14-2, and the other end A through hole 46 is formed on the side. The auxiliary arm 42 matches the through holes 30-1 and 30-2 while bringing the notches 28-1 and 28-2 of the two support arms 14-1 and 14-2 into contact with each other, and an arbitrary angle θ The projecting portions 32-1 and 32-2 are engaged with arbitrary engagement holes 45-1 and 45-2 formed in the support portion 44 on one end side, and the through holes 30-1 and 30-2 are engaged. By inserting the fixing screw 40 fitted with the fixing spring 38 and screwing the fixing screw 40 into the screw hole 43 on one end side, the two supporting arms 14-1 and 14 are elastically applied by the fixing spring 38. -2 is supported to be rotatable at one end and fixed at an arbitrary angle. Further, the auxiliary arm 42 inserts a fixing screw 50 in which a fixing spring 48 is fitted into the through hole 46 on the other end side, and the fixing screw 50 is screwed into the screw hole 34 of the support portion 20 of the X-ray imaging holder 16. By wearing, the other end side is supported by the elastic force of the fixing spring 48 so as to be rotatable to the support portion 20 and fixed at an arbitrary angle.

  The X-ray imaging auxiliary tool 4 provided with the auxiliary arm 42 is configured so that the rotation center P2 of the fixing screw 40 is separated from the support portion 20 of the X-ray imaging holder 16 with respect to the rotation center P1 of the fixing screw 50. The two support arms 14-1 and 14-2 are supported by the auxiliary arm 42. At this time, the auxiliary arm 42 and the two support arms 14-1 and 14-2 are required to have the X-ray incident angles of the two adapter units 12-1 and 12-2 with respect to the X-ray imaging holder 16. The rotation centers P1 and P2 are respectively set so as to have an angle. In addition, the adapter parts 12-1 and 12-2 can be adjusted at any angle with respect to the surface of the X-ray imaging holder 16 so that the orientation of the adapter parts 12-1 and 12-2 can be adjusted (not shown). To the base ends of the support arms 14-1 and 14-2.

  As a result, the X-ray imaging auxiliary tool 4 provided with the auxiliary arm 42 positions the X-ray imaging holder 16 behind the upper right side of the upper jaw in the oral cavity 52 as shown in FIG. When the bite block 24 of the imaging holder 16 is bitten, one end side (adapter part 12-1 and 12-2 side) of the auxiliary arm 42 jumps out of the oral cavity 52 and wraps around to the right cheek. X-ray imaging can be performed. In addition, when radiographing the maxillary left molar in the oral cavity 52, the auxiliary arm 42 is rotated in the reverse direction, and the adapter parts 12-1 and 12-2 are also rotated 180 degrees and used for the left side, or By replacing the left auxiliary arm (not shown) and using it, the left molar can be radiographed.

  Further, the X-ray imaging auxiliary tool 4 has a substantially letter F shape as shown in FIGS. 5 and 6 so that the imaging angle can be arbitrarily changed while taking into account the case of X-ray imaging of a molar or the like. While providing the shape auxiliary arm 56, the adapter parts 12-1 and 12-2 can be provided with inverted T-shaped fixing parts 58-1 and 58-2.

  The auxiliary arm 56 is a curved support part 60 to which the fixing parts 58-1 and 58-2 of the adapter parts 12-1 and 12-2 are fixed, and supports the X-ray imaging holder 16 continuously to the support part 60. It consists of a linear extension 62 fixed to the part 20. A plurality of fixing holes 64 are formed in the support portion 60 at predetermined intervals. The adapter parts 12-1 and 12-2 are provided with protruding parts 66-1 and 66-2 fitted into the fixing holes 64 in the fixing parts 58-1 and 58-2.

  In the X-ray imaging auxiliary tool 4, the extension 62 of the auxiliary frame 56 is fixed to the support portion 20 of the X-ray imaging holder 16, and the fixing portions 58-1 and 58-are fixed to arbitrary fixing holes 64 of the support portion 60. By fitting the two protrusions 66-1 and 66-2, the adapter parts 12-1 and 12-2 can be fixed at an arbitrary photographing angle, and the auxiliary arm 56 goes around the cheek. The X-ray imaging holder 16 can be positioned in the back of the oral cavity, and X-ray imaging of a molar or the like can be performed.

  In this way, this X-ray imaging auxiliary tool 4 can be used in the vertical and horizontal directions with one auxiliary tool and can be disinfected. It is light and can be disassembled and stored compactly with titanium, aluminum, plastic, stainless steel, etc. It has the condition that it can be done.

  The X-ray imaging auxiliary tool 4 is used in an X-ray imaging method and an X-ray imaging image processing method. An X-ray imaging method and an X-ray imaging image processing method using the X-ray imaging auxiliary tool 4 are performed by an X-ray imaging processing device 68 as shown in FIG. The X-ray imaging processing device 68 includes the X-ray imaging device 2 including the X-ray generator 6 and the CCD sensor 10, and processing means 70 that performs imaging processing and X-ray imaging image processing of the X-ray imaging device 2. And an input means 72 for inputting a command to the processing means 70 and a monitor means 74 for displaying the processed image.

  The processing means 70 of the X-ray imaging processing apparatus 68 includes an X-ray imaging performing means 76, an X-ray imaging image capturing means 78, a distance measuring means 80, a plane coordinate drawing means 82, and a plane slice image creating means 84. 3D image generation means 86.

  The X-ray imaging execution means 76 controls the operations of the X-ray generator 6 and the CCD sensor 10 of the X-ray imaging apparatus 2 to detect X-rays that have passed through the teeth by irradiating the teeth with X-rays. The X-ray image capturing unit 78 captures the X-ray image of the teeth detected by the CCD sensor 10 into the processing unit 70. The distance measuring means 80 measures the distance from the imaging reference line to two points in the width direction of the X-ray image. The plane coordinate drawing means 82 plots the distances to two points of the measured X-ray image on the plane coordinate axis, and draws projection lines from the two points. The plane slice image creating means 84 uses a circle or an ellipse as a closed curve figure inscribed in a quadrilateral area surrounded by four projection lines drawn from two points of two X-ray images. Create a plane slice image. The three-dimensional image generation unit 86 generates a three-dimensional image by superimposing planar slice images.

  Next, an X-ray imaging method using the X-ray imaging auxiliary tool 4 and a method for processing the obtained X-ray imaging image will be described. Here, as shown in FIG. 8, an X-ray imaging method for performing X-ray imaging of the fourth tooth Z of the lower jaw from an angle of 45 degrees to the left and right and a processing method for the obtained X-ray imaging image will be described.

  Normally, the size of the CCD sensor 10 as the X-ray imaging means is 512 × 768 pixels as shown in FIG. If the X-ray image of the tooth Z does not fit in the CCD sensor 10 that detects X-rays that have passed through the tooth Z that is the subject, the size of the CCD sensor 10 is increased. Further, no matter what direction the tooth Z faces, if the X-ray is irradiated at an X-ray incident angle of 45 degrees to the CCD sensor 10, a three-dimensional image formation of the tooth Z displayed on the CCD sensor 10 is performed. There is no problem with this algorithm. Further, the incident angle of the X-rays irradiated to the CCD sensor 10 can be determined by the developmental and / or morphological angle of the tooth.

  First, an X-ray imaging method and a processing method from the left side will be described.

(1) In the X-ray imaging method, as shown in FIG. 8, the X-ray generator 6 that is an X-ray source for generating X-rays of the X-ray imaging apparatus 2 and the X-rays that have passed through the tooth Z that is the subject. The tooth Z (the lower jaw No. 4) as the subject is positioned between the CCD sensor 10 as the X-ray imaging means for detecting the above.

(2) The X-ray generator 6 that generates X-rays is arranged such that the X-ray imaging auxiliary tool 4 allows the X-ray generator 6 to emit X-rays at an angle of 45 degrees from the left side. The X-ray irradiation unit 8 is mounted using 12-1.

  At this time, the positional relationship (distance) between the CCD sensor 10 and the tooth Z is such that X passes through the tooth Z when the X-ray generator 6 emits X-rays at an angle of 45 degrees to the left with respect to the CCD sensor 10. The tooth Z and the CCD sensor 10 are placed at such a distance that the line is detected and the projected X-ray image is contained in the CCD sensor 10.

(3) In order to measure the relative distance of the X-ray image obtained by X-ray imaging from 45 degrees to the left and right with respect to the CCD sensor 10, as shown in FIG. An imaging reference line (A1 ′) for detecting the position information of the tooth Z is provided in each pixel.

(4) X-ray imaging is performed on the CCD sensor 10 from the left 45 degrees to obtain an X-ray imaging image L1 from the left 45 degrees. An X-ray image of the tooth Z projected in the X-ray image L1 obtained at this time is Z1, and an imaging reference line is A1 '.

(5) The X-ray image Z1 of the tooth Z projected on the obtained X-ray image L1 is obtained by using the outline points of the marginal width (the inside and outside of the outline line in the width direction of the tooth Z). Point) and the distances (X1 and X2) from the photographing reference line A1 ′ are measured.

  As shown in FIG. 10, two points on the inner side and the outer side in the width direction of the X-ray image Z1, which is the edge portion of the tooth Z, exist on the same horizontal pixel column (row). As a result, the pixel column (row) of the pixels of the CCD sensor 10 passing through two points where the distance between the outline points (hereinafter referred to as edge portions) of the edge width of the X-ray image Z1 is measured is expressed as n + 1. deep. In FIG. 10, in order to explain the two outline points (X1 and X2) of the edge width of the X-ray image Z1 from the left of the tooth Z displayed on the X-ray image L1, respectively. The X-ray image Z1 is described as being divided into two images, the inner side and the outer side, but in actuality, it is one X-ray image Z1.

(6) In order to replace the distance (X1 and X2) of the two outer contour points of the measured edge with the plane coordinate axis, as shown in FIG. 11, the X-ray imaging is performed with the imaging reference line A1 ′ as the Y axis. A pixel column (row) passing through two points (X1 and X2) measured at the edge of the image Z1 and perpendicular to the Y axis that is the imaging reference line A1 ′ is defined as the X axis.

(7) Two points (X1 and X2) at the edge of the X-ray image Z1 measured in (5) are plotted on the plane coordinate axis.

  For example, as shown in FIG. 10, since the distances to the two measured points at the edge of the X-ray image Z1 projected from the Y-axis that is the imaging reference line A1 ′ are X1 and X2, respectively, As shown in FIG. 11, the measured positions of the two points (X1, X2) on the coordinate axis can be plotted as (X1,0) and (X2,0).

(8) Projection lines B1 and B2 are drawn from the two points (X1, 0) and (X2, 0) plotted on the coordinates at the same 45-degree angle as the imaging angle in the X-ray imaging direction side.

  Next, an X-ray imaging method and processing method from the right side will be described.

(9) The X-ray generator 6 that generates X-rays is adapted so that the right-side adapter unit is used by the X-ray imaging aid 4 so that the CCD sensor 10 is irradiated with X-rays at an angle of 45 degrees from the right side. The X-ray irradiation unit 8 is mounted using 12-2.

  At this time, the position of the tooth Z and the position of the CCD sensor 10 obtained by X-ray imaging from the left 45 degrees with respect to the CCD sensor 10 are not moved, and only the X-ray generator 6 is moved 45 degrees to the right with respect to the CCD sensor 10. It moves to the position where X-rays are irradiated at an incident angle of. That is, in FIG. 1, the X-ray generator 6 is moved and attached to the right adapter section 12-2.

(10) In order to measure the relative distance of the X-ray image obtained by X-ray imaging from 45 degrees to the left and right with respect to the CCD sensor 10, as shown in FIG. An imaging reference line (A1 ″) for detecting the position information of the tooth Z is provided in each pixel.

(11) X-ray imaging is performed on the CCD sensor 10 from the right 45 degrees, and an X-ray imaging image L2 from the right 45 degrees is obtained. The X-ray image of the tooth Z projected in the X-ray image L2 obtained at this time is Z2, and the reference line is A1 ″.

(12) The X-ray image Z2 displayed on the obtained X-ray image L2 determines the outline points of the marginal width (two points on the inside and outside of the outline line in the width direction of the tooth Z). Then, the distances (X3 and X4) from the photographing reference line A1 ″ are measured.

  At this time, since the inner and outer two points in the width direction of the X-ray image Z2, which is the edge of the tooth Z, exist on the same horizontal pixel column (row) as shown in FIG. Two points at the edge of the X-ray image Z2 located on the pixel row (row) n + 1 of the pixel (row) of the CCD sensor 10 of the line image L2 are measured. The pixel array (row) of pixels of the (n + 1) -th CCD sensor 10 of the X-ray image L2 is a pixel of the CCD sensor 10 passing through two points at the edge of the X-ray image Z1 determined by the X-ray image L1. By making the pixel column (row) n + 1 the same as the pixel column (row), it can be used as a reference line for creating a three-dimensional image.

(13) In order to replace the distance (X3 and X4) of the two outer contour points of the measured edge with the plane coordinate axis, as shown in FIG. 13, the X-ray imaging is performed with the imaging reference line A1 ″ as the Y axis. A pixel column (row) passing through two points (X3 and X4) measured at the edge of the image Z2 and perpendicular to the Y axis as the imaging reference line A1 ″ is set as the X axis.

(14) The two points (X3 and X4) at the edge of the X-ray image Z2 measured in (12) are plotted on the plane coordinate axis.

  For example, as shown in FIG. 12, since the distances from the Y axis which is the imaging reference line A1 ″ to the two measured points of the edge of the X-ray image Z2 projected are X3 and X4, respectively, As shown in FIG. 13, the measured positions of the two points (X3 and X4) on the coordinate axis can be plotted as (X3, 0) and (X4, 0).

(15) From (X3, 0) and (X4, 0) plotted on the coordinates, the projection lines B3 and B4 are drawn at the same 45 degree angle as the imaging angle on the X-ray imaging direction side.

(16) When the two coordinates of the two X-ray images Z1 and Z2 of the tooth Z obtained by X-ray imaging from the left and right directions are plotted on the same coordinate, the result is shown in FIG. As described above, the four projection lines B1 to B4 drawn from each coordinate intersect on the plane coordinates to create a quadrangle surrounded by the four projection lines B1 to B4.

(17) As shown in FIG. 15, a circle inscribed in the projection lines B1 to B4 defining the created quadrangle or an inscribed ellipse is created. By performing this processing, it is possible to draw a planar slice image D (cross-sectional view) of a tooth that is an X-rayed subject.

  The basic method of processing the two X-ray images Z1 and Z2 of the tooth Z obtained by X-ray imaging from the left and right directions is to create a circle inscribed in a quadrangle as shown in FIGS. If an inscribed circle cannot be created, an inscribed ellipse is created. Alternatively, an inscribed circle or an inscribed ellipse is created from the morphological characteristics of each tooth type of the tooth root based on the generally-known cross-sectional shape of the tooth root.

  In this case, it is possible to grasp the rough outline of the tooth Z by photographing an X-ray image of the front surface of the tooth Z as a subject before performing X-ray imaging twice at an angle of 45 degrees on the left and right. It is possible to create a slice image close to the tooth Z, which is an actual subject, by creating a planar slice image D (cross-sectional view) while matching with the morphological characteristics of each tooth type at the root portion.

  When the distance between the CCD sensor 10 and the X-ray generator 6 is small, the projection lines B1 and B2 and the projection lines B3 and B4 are not parallel lines, and the projection lines B1 and B2 and the projection lines B3 and B4 are In some cases, two sides of a triangle intersecting at the focal point of the X-ray generator 6 may be exhibited.

(18) The processing of (17) is performed for each pixel of the CCD sensor 10 in the positive direction of the Z-axis in order from the root tip to the crown, and a planar slice image D (for each pixel of the CCD sensor 10) (Cross section).

  For example, as shown in FIG. 18, a plane slice image (cross-sectional view) obtained from the measurement of the edge of the n-th X-axis tooth Z of the pixel n of the CCD sensor 10 is denoted as D0, and the pixel n + 1-th pixel of the CCD sensor 10 is obtained. A plane slice image (cross-sectional view) obtained from the measurement of the edge portion of the X-axis tooth Z is D1, and the plane obtained from the measurement of the edge portion of the pixel n + second X-axis tooth Z of the CCD sensor 10 Slice images (cross-sectional views) are sequentially created in the positive direction of D2,.

  At this time, the plane slice image D (cross-sectional view) is developed for each pixel of the CCD sensor 10, but the edges of the 45-degree X-ray images Z1 and Z2 projected on the left and right X-ray images L1 and L2 are displayed. When measuring the distance of the part and plotting it on the plane coordinate axis, since the measurement is performed only on the X axis, the Y axis coordinate is always Y = 0 (for example, coordinates such as (X, 0)) on the plane coordinate axis It will be expanded to.

(19) As shown in FIG. 19, the plane slice image D (cross-sectional view) for each pixel of the CCD sensor 10 obtained in the above (18) is the nth plane of the pixel n of the CCD sensor 10 at the tip of the tooth root. The slice images D0 (cross-sectional view) are sequentially stacked in the positive direction of the Z axis.

  When this superposition is performed, the position of the planar slice image D (cross-sectional view) created for each pixel of the CCD sensor 10 can be grasped by the distance from the Y axis that is the reference line. The plane slice images D are sequentially overlapped with respect to the origin of the axis and the X axis.

  The origins of the Y axis and the X axis, which are the references, serve as a position reference when the plane slice images D are overlapped. As a result, the positional information of the created planar slice image D (cross-sectional view) is known, and the roots are overlapped in the positive direction of the Z axis of each pixel in accordance with the origins of the reference Y axis and X axis. It is possible to grasp the situation of the music of the club. At this time, when superimposing on the Z axis, one slice width is determined in consideration of the pixel size of the Z axis.

(20) A three-dimensional image is generated by superimposing the planar slice image D (cross-sectional view) using three-dimensional image generation software such as volume rendering software.

  At this time, the external shape of the tooth Z obtained here is only an approximate three-dimensional image, but the anatomical form of each tooth has its characteristics. Can do. In addition, the curvature of the root and root canal can be accurately displayed, and a thin root canal that is not reflected in the X-ray image can be predicted and displayed as an image. The resolution of the image can be constructed as a three-dimensional image without reducing the resolution capability of the CCD sensor or other image recording.

  In this way, X-ray imaging is performed from the left and right directions by the X-ray imaging auxiliary tool 4 to obtain two X-ray imaging images, and the above-described processing is performed on the two X-ray imaging images obtained. By doing so, it is possible to form a three-dimensional image of a tooth, and from this three-dimensional image, it becomes possible to grasp the root canal shape (curvature state and form of the root canal) with individual differences and the like, and reliably Tube treatment can be performed.

  In this embodiment, the case where there is one tooth root has been described. However, even when there are a plurality of tooth roots, it is possible to obtain a three-dimensional image by performing the same imaging method and processing method. In this embodiment, X-ray imaging was performed from the left and right directions of the tooth to obtain two X-ray imaging images, and a three-dimensional image of the tooth was formed from the two X-ray imaging images. By further increasing the photographing direction, a finer three-dimensional image of the tooth can be formed.

  According to the present invention, an image is taken from the left and right directions at an arbitrary X-ray incident angle with respect to a tooth, an approximate slice image of a cross section of a desired portion is created using the obtained two X-ray images, By performing the process of creating a three-dimensional image by superimposing multiple slice images, it is possible not only to know the curvature and form of the root canal, but also to predict a root canal that is so thin that it cannot be seen in an X-ray image Therefore, root canal treatment can be surely performed.

It is a perspective view of the X-ray imaging state of the auxiliary tool for X-ray imaging which shows an Example. It is a perspective view from the lower side of the auxiliary tool for X-ray imaging. It is a perspective view which shows the 1st modification of the auxiliary tool for X-ray imaging. It is explanatory drawing which shows the usage condition of the auxiliary tool for X-ray imaging of FIG. It is a perspective view which shows the 2nd modification of the auxiliary tool for X-ray imaging. FIG. 6 is an enlarged explanatory view of a main part of a support part of the X-ray imaging auxiliary tool in FIG. 5. It is a block diagram of an X-ray imaging processing apparatus. It is explanatory drawing which shows the X-ray imaging state of a tooth. It is explanatory drawing of a CCD sensor. (A) is a front view for explaining the outer contour point inside the X-ray image from the left, and (B) is a front view for explaining the outer contour point outside the X-ray image from the left. It is explanatory drawing of the plane coordinate axis which drawn the external shape point and projection line of the X-ray imaging image from the left. (A) is a front view for explaining the outer contour point of the X-ray image from the right, and (B) is a front view for explaining the outer contour point of the X-ray image from the right. It is explanatory drawing of the plane coordinate axis which drawn the external shape point and projection line | wire of the X-ray imaging image from the right. It is explanatory drawing of the plane coordinate axis which drew each outline point and each projection line of the X-ray imaging image from two directions on the left and right. It is explanatory drawing of the plane coordinate axis which drawn the circle | round | yen in the part which each projection line of the X-ray imaging image from right-and-left 2 direction crosses. (A) is a front view that combines X-ray images from the left and right directions, and (B) is an explanatory diagram of the plane coordinate axes that are drawn by combining the outline points and projection lines of the X-ray images from the left and right directions. It is. It is the perspective view of the plane coordinate axis which put together the X-ray photography image from two right and left directions, and drawn each outline point and each projection line. It is explanatory drawing of the plane coordinate axis which drew the plane slice image for every pixel of a CCD sensor. It is explanatory drawing in the three-dimensional coordinate axis which piled up the plane slice image drawn for every pixel of the CCD sensor.

Explanation of symbols

2 X-ray imaging apparatus 4 X-ray imaging auxiliary tool 6 X-ray generator 8 X-ray irradiation unit 10 CCD sensor 12-1 and 12-2 adapter unit 14-1 and 14-2 Support arm 16 X-ray imaging holder 18 Holding Section 20 Support section 24 Bite block 32-1, 32-2 Protrusion section 36-1, 36-2 Engagement hole 38 Fixing spring 40 Fixing screw 68 X-ray imaging processing apparatus 70 Processing means 72 Input means 74 Monitor means 76 X-ray Imaging execution means 78 X-ray imaging image capturing means 80 Distance measuring means 82 Planar coordinate drawing means 84 Planar slice image creating means 86 Three-dimensional image generating means

Claims (4)

An adapter unit to which an X-ray irradiation unit of an X-ray source for generating X-rays is detachably mounted, a support arm extending from the adapter unit in the X-ray irradiation direction, and a tip of the support arm An X-ray imaging auxiliary tool including an X-ray imaging holder that detachably holds an X-ray imaging means for detecting X-rays irradiated from the X-ray irradiation unit and passing through the subject. Two adapter parts that are spaced apart from each other in the left and right directions with respect to the X-ray imaging holder are provided so that the two adapter parts can be angled in the left and right directions with respect to the X-ray imaging holder. An auxiliary tool for X-ray imaging, characterized in that the tips of two extending support arms are supported so as to be rotatable to the X-ray imaging holder and fixed at an arbitrary angle. An object is positioned between an X-ray source that generates X-rays and an X-ray imaging unit that detects X-rays emitted from an X-ray irradiation unit of the X-ray source. X-ray imaging is performed by irradiating the subject with X-rays from the X-ray irradiation unit of the X-ray source from the left and right directions at an X-ray incident angle to obtain an X-ray image of the subject from the left and right directions. A characteristic X-ray imaging method. X-ray imaging is performed by irradiating the subject with X-rays from the X-ray irradiator of the X-ray source from the left and right directions at an arbitrary X-ray incident angle with respect to the X-ray imaging unit, and the right side with respect to the X-ray imaging unit An X-ray image obtained by performing X-ray imaging with an arbitrary X-ray incident angle from the direction is positioned on the left side, and an arbitrary X-ray incident angle is applied to the X-ray imaging unit from the left direction. An X-ray image obtained by X-ray imaging is positioned on the right side, and imaging reference lines for detecting position information of a subject in each of the X-ray images positioned on the left and right sides are overlapped, and the two directions are left and right An outline point with an arbitrary edge width is determined for the X-ray image obtained from the above, and a projection line is drawn from the outline point with an arbitrary edge width in the X-ray incident angle direction and surrounded by the drawn projection line Create a closed curve figure inscribed in the projected line in the specified area, and use the obtained closed curve figure for any side of the subject. Processing method of the X-ray imaging image, characterized in that to obtain a figure that approximates the cross-sectional view in outline point width. A circle or an ellipse is created as a closed curve figure inscribed in the projection line in an area surrounded by the projection line drawn from the outline point of the arbitrary marginal width, and a plurality of the obtained circles or ellipses are overlapped The method of processing an X-ray image according to claim 3, wherein an approximate three-dimensional image is created.

Images