JP5658133B2 - Phantom for medical X-ray equipment - Google Patents

Description

  The present invention relates to a phantom for a medical X-ray imaging apparatus used for evaluation for an X-ray imaging apparatus.

  As a phantom of a medical X-ray imaging apparatus for dentistry or the like, what is called an extracted tooth obtained by extracting a human tooth at the time of dental treatment is used in part.

  In addition, as disclosed in Patent Document 1, it is also considered that a phantom for an X-ray CT imaging apparatus is formed by a porous member made of a rubber material.

  Further, as disclosed in Patent Document 2, it is also considered to form a bone disease imaging apparatus evaluation phantom using an X-ray attenuating substance similar to bone or cartilage made of hydroxyapatite or a tan resin.

JP-A 63-264044 JP 2007-289560 A

  However, it is difficult to obtain human teeth, and there is a problem that it is inferior in preservability.

  In addition, the phantom for an X-ray CT imaging device formed by a porous member made of a rubber material is significantly different from human teeth and bones. There is a problem that it is difficult to do.

  In addition, the bone disease imaging device evaluation phantom made of hydroxyapatite or retane-based resin is configured close to the structure of actual human teeth and bones, but the structure of the living body attracting attention in clinical settings is precise. Even if a test image is taken using this phantom, the problem remains that the reproducibility of the fine structure of human teeth and bones is poor and it is still difficult to perform an appropriate evaluation.

  Therefore, the present invention has an object to provide a phantom for a medical X-ray imaging apparatus that is excellent in availability and storage, and suitable for evaluation for an X-ray imaging apparatus, etc., and excellent in reproducibility of a living body. And

  In order to solve the above problem, a phantom for a medical X-ray imaging apparatus according to a first aspect includes a jawbone part from which a part of a jaw jaw of a pig is cut out, and an exterior resin part that covers the jawbone part.

  A 2nd aspect is a phantom for medical X-ray imaging apparatuses which concerns on a 1st aspect, Comprising: The said jawbone site | part is a thing which the corruption suppression process was performed.

  A 3rd aspect is a phantom for medical X-ray imaging apparatuses which concerns on a 1st or 2nd aspect, Comprising: The said jaw bone site | part contains at least one molar of at least one pig and at least one part of an alveolar bone.

  A 4th aspect is a phantom for medical X-ray imaging apparatuses which concerns on any one 1st-3rd aspect, Comprising: The said exterior resin part has X-ray transmittance equivalent to the soft tissue of a human body.

  A 5th aspect is a phantom for medical X-ray imaging apparatuses which concerns on any one 1st-4th aspect, Comprising: The said exterior resin part is transparent or translucent.

  The sixth aspect is a phantom for a medical X-ray imaging apparatus according to any one of the first to fifth aspects, wherein a plurality of X-rays having different X-ray transmittances in the exterior resin portion. A physical phantom having a transmission part is embedded.

  A seventh aspect is a phantom for a medical X-ray imaging apparatus according to any one of the first to sixth aspects, wherein an outer shape of the exterior resin portion is formed into a shape that can be placed on a plane. ing.

  An eighth aspect is a phantom for a medical X-ray imaging apparatus according to any one of the first to seventh aspects, wherein an outer shape of the exterior resin portion is formed in any one of a rectangular parallelepiped, a cube, or a cylinder. Has been.

  According to the phantom for a medical X-ray imaging apparatus according to the first aspect, since the jaw bone part in which a part of the jaw bone of the pig is cut out is used, the availability and the thickness and structure of the actual subject are reduced. Since it can be reproduced, it is suitable for evaluation for an X-ray imaging apparatus. Moreover, since the jawbone part is covered with the exterior resin part, it is excellent in preservability and hygienic management is easy.

  According to the second aspect, the jawbone part has been subjected to the anti-corruption treatment, and thus has better storage stability.

  According to the third aspect, the jaw bone part includes at least one porcine molar tooth and at least a part of the alveolar bone, and thus can more closely resemble a human tooth and its peripheral structure. More suitable for evaluation.

  According to the 4th aspect, since the said exterior resin part has the X-ray transmittance corresponding to the soft tissue of a human body, it is more suitable for the evaluation for X-ray imaging apparatuses.

  According to the 5th aspect, a jawbone site | part can be visually recognized from the outside.

  According to the sixth aspect, the X-ray imaging apparatus can be evaluated by using each X-ray transmission part of the physical phantom, and therefore, using one medical X-ray imaging apparatus phantom, Furthermore, it is convenient because other physical evaluations such as spatial resolution and contrast can be performed.

  According to the seventh aspect, X-ray imaging can be performed in a state where the phantom for the medical X-ray imaging apparatus is stably placed.

  According to the eighth aspect, X-ray imaging can be performed in a state where the phantom for the medical X-ray imaging apparatus is stably placed.

It is a perspective view which shows the phantom for medical X-ray imaging apparatuses. It is a front view which shows the phantom for medical X-ray imaging apparatuses. It is a rear view which shows the phantom for medical X-ray imaging apparatuses. It is a top view which shows the phantom for medical X-ray imaging apparatuses. It is a side view which shows the phantom for medical X-ray imaging apparatuses. It is explanatory drawing which shows the part cut out from the jaw bone of a pig. It is explanatory drawing which shows the part cut out from the jaw bone of a pig. It is a perspective view which shows the modification of the phantom for medical X-ray imaging apparatuses. It is a perspective view which shows the other modification of the phantom for medical X-ray imaging apparatuses. It is a perspective view which shows the further another modification of the phantom for medical X-ray imaging apparatuses. It is sectional drawing which shows an example of a physical phantom.

  Hereinafter, a phantom for a medical X-ray imaging apparatus according to an embodiment will be described. 1 to 5 are views showing a phantom 20 for a medical X-ray imaging apparatus.

  The medical X-ray imaging apparatus phantom 20 is used as an imaging object by the medical X-ray imaging apparatus. For example, the phantom 20 for medical X-ray imaging apparatus is used for initial setting, maintenance, correction, etc. before shipment of the medical X-ray imaging apparatus, explanation for users (medical workers such as dentists) at the installation site, etc. In each of the above scenes, it is used as an object to be photographed for testing.

  Here, as a medical X-ray imaging apparatus, for example, dental X-rays such as a dental oral X-ray imaging apparatus, a dental panoramic X-ray imaging apparatus, a dental cephalometric imaging apparatus, and a dental X-ray CT imaging apparatus. An imaging apparatus, and further an otolaryngological X-ray imaging apparatus and an ophthalmic X-ray imaging apparatus are included.

  This phantom 20 for medical X-ray imaging apparatus includes a jawbone part 30 and an exterior resin part 40 that covers the jawbone part 30.

  The jawbone part 30 is formed by cutting a part of a pig jawbone. FIGS. 6 and 7 are explanatory views showing a part cut out from the jaw bone 10 of the pig. In addition, in FIG. 6, the jawbone 10 of the pig has shown the state observed from the lingual side. In FIG. 7, the right side of the alveolar bone 12 is the lingual side, the left side is the cheek side, and FIG.

  The porcine jawbone 10 is configured such that a plurality of teeth 15 are arranged in a row on an alveolar bone 12 including a trabecular bone. 6 and 7 show a portion including a plurality of molar teeth 15. The molar 15 includes a dentin portion 15a constituting a main portion and an enamel portion 15b covering the surface thereof. In addition, a pulp 15 c exists inside the molar 15, and a periodontal ligament exists between the molar 15 and the alveolar bone 12. Further, permanent teeth HTa and HTb (in FIG. 1 to FIG. 5, permanent teeth HT) are buried below the plurality of molar teeth 15.

  This pig jawbone 10 is used because it is structurally similar to the human jawbone, and it is also a monkey or sheep, goat, rabbit, deer, dog, cat, rabbit, guinea pig, ferret. This is because it can be obtained easily and inexpensively compared to jaw bones such as foxes and weasels.

  Further, when the jawbone part 30 is cut out from the jawbone 10 of the pig, it is preferable to cut out so as to include at least a part of the porcine molar 15 and the alveolar bone 12. This is because the jawbone portion 30 can be more similar to the human tooth and the surrounding structure. Here, the jawbone part 30 is cut out so as to include a plurality of molar teeth 15 arranged in succession and the alveolar bone 12 near the root of the plurality of molar teeth 15. More specifically, in the jawbone 10, a pair of longitudinal cut surfaces are formed on the outer sides of the three molars 15 arranged in succession (the first anterior molar, the second anterior molar, and the third anterior molar in order from the left side in FIG. 2). The jaw bone part 30 is cut out by forming a transverse cut surface at the lower part of the pair of longitudinal cut surfaces. Cutting may be performed with a saw or the like.

  It is preferable that the jawbone 10 to be cut out is cut out so as to include at least one molar 15 that is the anterior molar tooth of the piglet, and to include the alveolar bone 12 below it. More preferably, the molar 15 is the second to fourth anterior molars. The anterior molars (except the first anterior molar) of the piglet are deciduous teeth, and therefore, permanent teeth HT, HTa, and HTb are buried below the deciduous teeth. This is because the jawbone part 30 can be made more similar to the tooth structure of a human child. However, the rear molars of the piglets may be cut out. In addition, since the rear molar and the first front molar are permanent teeth that do not change, when these molar teeth are cut out and used, the buried teeth under these molar teeth cannot be observed.

  Moreover, it is preferable that the jaw bone part 30 of a pig has been subjected to anti-corruption treatment. This is because if the anti-corrosion treatment is performed on the jawbone part 30, it is excellent in storage stability and hygienic. The anti-corruption treatment is performed by removing the soft tissue or processing the soft tissue into a state in which the soft tissue is difficult to decay. The anti-corruption process may be performed in the state of the jawbone 10 before cutting out, or may be performed in the state of the jawbone part 30 after cutting out. As a method of removing soft tissue, any method may be used as long as it is a method of removing a tissue that may be spoiled such as meat and that does not damage the tissue to be evaluated (observed). For example, use of drugs, methods using insects and microorganisms, and the like are conceivable. For drugs, insects or microorganisms, materials or seeds that act only on soft tissues may be used. Soft tissue removal is covered in a resin in a non-corrupted state so that at least the durability and appearance of the medical X-ray imaging apparatus phantom 20 are not impaired even if the tissue is not completely removed. Just do it. As a method for processing the soft tissue into a state in which it does not easily rot, there is drying. The drying may be natural drying or may be dried in a special drying chamber.

  The exterior resin part 40 covers the entire jawbone part 30 so that the jawbone part 30 is not exposed to the outside. The exterior resin part 40 covers the jawbone part 30 so that the preservation property of the jawbone part 30 can be improved. It is also possible to prevent a person from directly touching the jawbone part 30.

  But the exterior resin part 40 should just cover at least the tooth | gear part of the jawbone site | part 30 so that the molar 15 may not be exposed here. Accordingly, the bottom surface of the alveolar bone 12 may be exposed to the outside.

  The exterior resin portion 40 is preferably transparent or translucent. This is because the form of the jawbone part 30 can be visually recognized from the outside. In other words, the exterior resin part 40 is preferably transparent or translucent to such an extent that the jawbone part 30 can be visually recognized from the outside. However, since the medical X-ray imaging apparatus phantom 20 is used as an imaging target by the X-ray imaging apparatus, it is not essential that the exterior resin portion 40 is transparent or translucent.

  Moreover, it is preferable that the exterior resin part 40 has an X-ray transmittance corresponding to a soft tissue of a human body. Thereby, the state where the jawbone part 30 is surrounded by the soft tissue of the human body can be reproduced, and the medical X-ray imaging apparatus phantom 20 can be made suitable for evaluation of medical X-ray imaging. .

  Such a resin is preferably made of a material having an effective atomic number of 5.7 to 7.64. Here, the effective atomic number is a value obtained by evaluating how many atoms the atomic number corresponds to the influence or behavior on X-rays.

  Specifically, a polyurethane resin or an acrylic resin can be used as the resin, and it is particularly preferable to use a transparent or translucent resin from the above viewpoint.

  Moreover, it is preferable that the outer shape of the exterior resin part 40 is formed in a shape that can be placed on a plane. Here, the outer shape of the exterior resin part 40 is formed in a rectangular parallelepiped shape. Further, one main surface (bottom surface) of the exterior resin portion 40 is substantially parallel to the bottom surface of the jawbone portion 30.

  The outer shape of the exterior resin portion only needs to be a shape that can be placed on a flat surface, and may be a cubic exterior resin portion 40B like a phantom 20B for a medical X-ray imaging apparatus shown in FIG. Further, as in the medical X-ray imaging apparatus phantom 20C shown in FIG. 9, a cylindrical exterior resin portion 40C may be used. In a state where the exterior resin portion is placed on a plane, it is preferable that the plane and the bottom surface of the jawbone portion 30 be in a parallel state.

  Thus, by forming the outer shape of the exterior resin portion 40 into a shape that can be placed on a plane, the medical X-ray imaging apparatus phantom 20 can be stably placed in the imaging target space of the apparatus. X-ray imaging can be performed in an environment in which the state of the teeth and jawbones that are subjects in actual imaging is reproduced while being placed.

  An example of the size of the exterior resin part 40 and an example of the position of the jawbone part 30 in the exterior resin part 40 will be described.

  It is preferable that the width W, the depth D, and the height H of the exterior resin portion 40 are 40 to 50 mm, 20 to 30 mm, and 30 to 40 mm, respectively. The height H is preferably larger than the receiver (sensor, film) of the X-ray imaging apparatus, but this is not essential. Moreover, it is preferable that the depth D of the exterior resin part 40 is a value which can project the jawbone part 30 to the same extent as when X-ray imaging of a human body during X-ray imaging.

  Further, it is preferable that a uniform space be formed between the surface of the jawbone portion 30 and the outer surface of the exterior resin portion 40 in the entire outer periphery of the jawbone portion 30. In addition, the arrangement direction of the molars 15 of the jawbone site 30 is preferably arranged along any surface of the exterior resin portion 40.

  Since it is desirable to form the phantom 20 for a medical X-ray imaging apparatus in a form as close as possible to the form of a living body as a subject, the outer periphery of the exterior resin part 40 from the end of the jawbone part 30 embedded in the exterior resin part 40 If the distance to the surface is 3 mm to 10 mm, it is preferable because the reproducibility of the living body as the subject is excellent. However, this specification is not strictly required in the design of the phantom 20 for medical X-ray imaging apparatus of the present invention.

  A transparent coating may be further applied to the outer surface of the exterior resin portion 40. In this case, the coating on the bottom surface of the exterior resin portion 40 may be omitted.

  According to the phantom 20 for a medical X-ray apparatus configured as described above, the jawbone portion 30 from which a part of the porcine jawbone 10 is cut out is used, so that the availability is excellent. Moreover, since a structure similar to a human tooth structure can be obtained, it is suitable for evaluation of an X-ray imaging apparatus, in particular, a dental X-ray imaging apparatus. Moreover, since the jawbone part 30 is covered with the exterior resin part 40, it is excellent in preservability.

  In addition, it is easy to obtain a certain number of swine jawbone parts 30 together. Therefore, when performing cutting, anti-corruption processing, sterilization, or the like, each operation process can be easily performed collectively.

  Further, in the phantom 20 for medical X-ray imaging apparatus, the trabecular bone of the jawbone 10, the periodontal ligament cavity where the periodontal membrane is present, the pulp, the dentin, and the enamel can be confirmed. The contrast difference can be confirmed. Since it is required in the clinical field that these biological parts can be clearly observed in the X-ray image, it is clinically meaningful to evaluate the X-ray image using these biological parts. Therefore, the configuration of the phantoms 20 and 20B to 20D for the medical X-ray imaging apparatus is suitable as an evaluation tool for X-ray imaging images.

  Further, a physical phantom 50 may be embedded in the exterior resin portion 40D as in the medical X-ray imaging apparatus phantom 20D shown in FIG. The physical phantom 50 has a plurality of X-ray transmission parts 51, 52, 53 having different X-ray transmittances. Here, the physical phantom 50 is a member formed of a resin such as an acrylic resin, and has holes 51, 52, and 53 having different depths on one main surface as shown in FIGS. doing. In FIG. 11, of the holes 51, 52, and 53, the hole 51 is the shallowest, the hole 53 is the deepest, and the hole 52 has an intermediate depth. The holes 51, 52, and 53 may be hollow or may be filled with a material having an X-ray transmittance different from that of the resin or the like constituting the physical phantom 50. When this physical phantom 50 is X-ray photographed from the opening side of the holes 51, 52, 53, it exhibits different X transmittances depending on the depth. Therefore, the portions of the physical phantom 50 in which the holes 51, 52, 53 are formed are a plurality of X-ray transmission portions that exhibit different X-ray transmittances. The X-ray transmittance exhibited by each of the holes 51, 52 and 53 is preferably a known value in order to be used for evaluation of a medical X-ray imaging apparatus. The resin such as acrylic resin that forms the physical phantom 50 embedded in the medical X-ray imaging phantom 20D may be the same as the exterior resin portion 40D used in the medical X-ray imaging phantom 20D. Good. If the resin member is common, a plurality of X-ray transmitting portions 51, 52, 53 can be directly designed in a part of the medical X-ray imaging phantom (near the jawbone portion 30).

  Thus, if the physical phantom 50 is embedded in the medical X-ray imaging apparatus phantom 20D, not only the evaluation of the X-ray imaging apparatus using the jawbone part 30 but also each X-ray transmission of the physical phantom 50 is performed. The X-ray imaging apparatus can be evaluated using the holes 51, 52, and 53 as parts.

  The form of the physical phantom embedded in the medical X-ray imaging apparatus phantom is not limited to the form of the above embodiment. A physical phantom is a test body used for calibration and measurement related to image quality performance for medical X-ray imaging apparatuses, and includes all specimens including a plurality of X-ray transmission portions having mutually different X-ray transmittances. Say. For example, a plurality of substances having different sizes (for example, a plurality of metal spheres having different diameters) may exhibit different X-ray transmittances due to their sizes, and the thickness may be stepped. Alternatively, the X-rays may be changed in an inclined shape so as to exhibit different X-ray transmittances depending on the thickness, or X-rays different from each other by combining a plurality of substances having different X-ray transmittances. You may make it exhibit the transmittance | permeability.

  Some specific examples of the physical phantom 50 will be described.

  For example, a physical phantom suitable for dental panoramic photography and cephalo photography includes an aluminum phantom or a low-resolution measurement phantom.

  What is called an aluminum phantom is a combination of pieces of aluminum with different thicknesses to change the thickness in a stepped or inclined manner, or a combination of aluminum and lead, etc. Rate.

  The phantom for low-resolution measurement is a combination of metal balls with different diameters, or a combination of holes with different diameters or holes with bottoms or holes with different depths. . In the former case, the X-ray transmittance varies depending on the diameter. In the latter case, the X-ray transmittance varies depending on the presence or absence of a hole or a bottomed hole, and the X-ray transmittance varies depending on the depth of the bottomed hole. In the design using holes with different diameters or holes with bottoms, the X-ray transmittance does not differ depending on the size of the diameter. The reason why the diameters of the holes or the bottomed holes are made different is to evaluate to what extent the photographed subject can be expressed as a photographed image (recognizable).

  Further, for example, a physical phantom including a resolution chart may be used. A resolution chart is a concentric, radial, grating, diffraction grating, or continuous shape formed by an X-ray superabsorber such as gold, lead, or tungsten. It is assumed that it is in a state where This resolution chart is used to measure the spatial resolution of the X-ray imaging apparatus, and exhibits different X-ray transmittances in the X-ray superabsorber part and the surrounding resin part enclosing the part. .

  A contrast phantom is used as a CT imaging phantom. Contrast phantom, for example, for evaluating whether or not there is a capability of resolving to the extent that the prosthetic tooth can be imaged and recognized when an image with a difference in X-ray absorption such as a prosthetic tooth is simultaneously photographed It is a phantom. As such a phantom, for example, a phantom for quantitative measurement of bone mineral content in which pieces (dental models) having different calcium concentrations are combined and embedded in a columnar resin, aluminum (corresponding to a prosthesis), calcium ( Examples include materials using a combination of different X-ray absorber parts such as teeth and bones), acrylic (equivalent to soft tissue), and parts without these subjects (equivalent to bubbles).

  Further, the physical phantom may be a form (wire phantom or the like) using a metal wire for measuring a spatial frequency as a phantom for measuring spatial resolution.

  A wire phantom is, for example, a wire made of metal or the like stretched in the space of a resin container (for example, a cylindrical container) having a thickness of about 1 to 2 mm, and a space through which the metal wire passes. Exhibit different X-ray transmittances. The wire may be a substance that sufficiently absorbs X-rays with respect to the surrounding resin or space (portion where there is no subject).

  A shape phantom may be used as a physical phantom for dental panoramic photography, cephalo photography, and CT photography evaluation. The shape phantom is a phantom including a subject whose shape such as length and angle is determined in advance, and is used for evaluating whether the captured image is the same magnification, whether there is no distortion, or the like.

  The subject may be any substance that can sufficiently absorb X-rays with respect to the resin portion or the space, and a material such as aluminum or stainless steel may be used from the viewpoint of good workability. Such a subject also exhibits different X-ray transmittances in a portion where the subject is present and a peripheral portion thereof.

  Examples of the shape of the shape phantom include, for example, a columnar shape, a stepped shape, and a resin in which aluminum spheres are embedded in a plate-like or cubic resin.

  In addition, each structure demonstrated in the said embodiment and each modification can be suitably combined unless it mutually contradicts.

  As described above, the present invention has been described in detail. However, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

  When the phantom for a medical X-ray imaging apparatus according to the present invention described above is used, it is possible to visually evaluate an X-ray image that is closely related to a use and purpose in a clinical field. Therefore, by using this phantom for medical X-ray equipment, constancy evaluation on the image quality at the time of factory shipment, periodic inspection (maintenance inspection), and confirmation evaluation of the captured image at the repair inspection Etc., it becomes possible for the evaluator to make the evaluation easier to understand. In addition, it is possible to explain the evaluation results in a more understandable manner for users such as doctors and staff at medical facilities.

DESCRIPTION OF SYMBOLS 10 Jaw bone 12 Alveolar bone 15 Molar 20, 20B, 20C, 20D Phantom for medical X-ray imaging apparatus 30 Jaw bone part 40, 40B, 40C, 40D Exterior resin part 50 Physical phantom 51, 52, 53 Hole

Claims (8)

The jawbone part from which part of the jawbone of the pig was cut,
An exterior resin part covering the jawbone site;
A phantom for a medical X-ray imaging apparatus. A phantom for a medical X-ray imaging apparatus according to claim 1,
The jawbone part is a phantom for a medical X-ray imaging apparatus, which has been subjected to anti-corruption treatment. A phantom for a medical X-ray imaging apparatus according to claim 1 or 2,
The phantom for a medical X-ray imaging apparatus, wherein the jawbone part includes at least one porcine molar tooth and at least a part of an alveolar bone. A phantom for a medical X-ray imaging apparatus according to any one of claims 1 to 3,
The exterior resin part is a phantom for a medical X-ray imaging apparatus having an X-ray transmittance corresponding to a soft tissue of a human body. A phantom for a medical X-ray imaging apparatus according to any one of claims 1 to 4,
The exterior resin portion is a transparent or translucent phantom for a medical X-ray imaging apparatus. A phantom for a medical X-ray imaging apparatus according to any one of claims 1 to 5,
A phantom for a medical X-ray imaging apparatus in which a physical phantom having a plurality of X-ray transmission parts having mutually different X-ray transmittances is embedded in the exterior resin part. A phantom for a medical X-ray imaging apparatus according to any one of claims 1 to 6,
A phantom for a medical X-ray imaging apparatus, wherein an outer shape of the exterior resin portion is formed in a shape that can be placed on a plane. A phantom for a medical X-ray imaging apparatus according to any one of claims 1 to 7,
A phantom for a medical X-ray imaging apparatus, wherein an outer shape of the exterior resin portion is formed in any one of a rectangular parallelepiped, a cube, and a cylinder.

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