WO2008056522A1

WO2008056522A1 - Radioactive image pickup device

Info

Publication number: WO2008056522A1
Application number: PCT/JP2007/070422
Authority: WO
Inventors: Yuko Shinden; Hiromu Ohara
Original assignee: Konica Minolta Medical & Graphic, Inc.
Priority date: 2006-11-09
Filing date: 2007-10-19
Publication date: 2008-05-15

Abstract

Intended is to provide a radioactive image pickup device for calculating and discriminating the aging of an affected part precisely while keeping the opening degree and direction of hand fingers being photographed. The radioactive image pickup device comprises a radioactive ray source for emitting a radioactive ray to a subject, detector holding means for holding a radioactive image detector to detect the radioactive ray emitted from the radioactive ray source and having passed through the subject, and a subject bed arranged between the radioactive ray source and the detector holding means for holding the subject, whereby a phase contrast image can be formed. The subject bed includes positioning means for holding the individual articulations of the subject at fixed relative positions.

Description

Specification

Radiation imaging equipment

Technical field

TECHNICAL FIELD [0001] The present invention relates to a radiographic imaging apparatus, and more particularly, to a radiographic imaging apparatus for diagnosing joint deformation.

Background art

Conventionally, it is necessary to fix a subject for radiographic imaging! For example, when photographing a digestive organ, as shown in Patent Document 1, the subject is covered with an air pillow. Devices that compress and fix the abdomen are known. In the case of a mammography apparatus, a subject is usually fixed on a subject table with a compression plate or the like.

As shown in FIG. 16, such a mammography apparatus 50 detects the radiation from the radiation source 51 that irradiates the subject H with radiation and the radiation source 51 that has passed through the subject H. A detector holding means 52 for holding the radiation image detector, and a subject table 53 for holding the subject H disposed between the radiation source 51 and the detector holding means 52 are provided. These components are provided along the vertical direction so that the subject can take a radiographic image while standing.

[0004] In addition, in order to sufficiently improve the contrast of an obtained radiographic image, a radiographic image capturing device that captures a phase contrast image is known (see, for example, Patent Documents 2 and 3). When capturing a phase contrast image, it is necessary to provide a predetermined distance between the radiation source and the subject and between the subject and the radiation image detector. Such phase contrast photography is one of the magnified photography methods.

[0005] Here, as one of the diseases appearing on the limbs, rheumatic diseases can be mentioned. In the case of rheumatic diseases, there are symptoms that appear in the bone, such as osteoporosis, and symptoms that appear in the cartilage, such as cartilage destruction. Since these symptoms appear the earliest in the cartilage portion of the limb, diagnosis has conventionally been performed using images obtained by photographing the joints of the fingers with MRI or the like. However, MRI imaging has the problem that it is difficult to observe changes in the joints of the fingers periodically by taking images with a heavy burden on the subject from the viewpoint of cost and time required for examination. The Patent Document 1: Japanese Patent Laid-Open No. 2005-40505

Patent Document 2: Japanese Patent Laid-Open No. 2004-173879

Patent Document 3: JP 2001-91479 A

Disclosure of the invention

Problems to be solved by the invention

[0006] Therefore, in recent years, by capturing a phase contrast image using an X-ray imaging apparatus, even when the X-ray absorption difference is small, such as between the soft bone part and its surroundings, the cartilage part having good visibility. The present applicant has proposed a technique for capturing the images. The present invention provides a radiographic imaging apparatus that generates an image of a joint including a cartilage with good visibility.

[0007] According to the radiographic imaging device of the present invention, it is possible to periodically perform imaging of a joint part of a subject's finger, and change with time of cartilage or the like of the joint part (for example, rubbing of the cartilage part) It is easy to do the observation by the comparative interpretation with multiple images and the observational diagnosis with the time-difference image (subtraction image), the early detection of rheumatic disease and the early treatment of the patient It is possible to suppress the spread of disease.

[0008] In the conventional mammography apparatus 50, since the finger is not fixed when the subject places his / her arm on the subject table 53, the degree of opening of the finger differs every time the image is taken, and the time of the affected part changes over time. There is a problem that it is difficult to accurately calculate and discriminate changes, but the radiographic imaging device of the present invention can solve such a problem. Therefore, it is possible to keep the degree and direction of the finger opening at the time of photographing substantially constant, and it is possible to detect a slight change with time by comparing the photographed finger images.

[0009] Further, regarding the thickness of the subject, the thickness of the subject such as the finger of the subject varies depending on the part. For example, the thickness is different at the tip of the wrist, back of the hand, fingertip, etc., and the thickness decreases as the tip gets closer. For this reason, if the X-ray intensity is adjusted according to the thickness of the tip, the X-ray intensity is insufficient on the wrist side, and an image suitable for diagnosis cannot be obtained. According to the image capturing device, an image suitable for diagnosis can be obtained by irradiating a subject having a different thickness depending on the part with radiation having an intensity corresponding to the thickness. The power S

Means for solving the problem

In order to solve the above-mentioned problem, the invention described in claim 1 is

A radiation source for irradiating the subject with radiation; detector holding means for holding a radiation image detector for detecting radiation from the radiation source that has passed through the subject; and between the radiation source and the detector holding means. A radiographic imaging device comprising: a subject table arranged to hold the subject; and a phase contrast image that can be generated, wherein the subject table is positioned to keep a relative position of each joint portion of the subject constant It has a means!

Further, the invention described in claim 2 is the radiographic image capturing device described in claim 1,

The positioning means is fixed to the subject table.

[0011] In addition, the invention described in claim 3 is the radiographic image capturing device described in claim 1,

The positioning means is detachably provided.

[0012] In addition, the invention described in claim 4 is the radiographic imaging device described in claim 1 or 2!

The subject table is a right-hand subject table and a left-hand subject table, and is detachably provided.

[0013] In addition, the invention described in claim 5 is the radiographic image capturing device described in claim 4,

An object base discriminating means for discriminating whether the subject base is a right hand subject base or a left hand subject base is provided.

[0014] Further, the invention described in claim 6 is the radiographic image capturing device described in claim 1,

The positioning means regulates the subject in the placement direction;

The radiation source emits radiation while changing the radiation intensity according to the placement direction of the subject regulated by the positioning means. [0015] Further, the invention according to claim 7 is the radiographic image capturing device according to claim 6,

Holding means for holding the radiation source, the object table and the detector holding means so that a phase contrast image can be generated; and

Fixing means for fixing the subject to the subject table,

The radiation source, the fixing means, and the detector holding means are arranged so that the end portion close to the subject is positioned almost on a straight line in the irradiation direction of the radiation emitted from the radiation source. Being done! /, Characterized in that.

[0016] The invention described in claim 8 is the radiographic imaging device described in claim 6 or 7! /,

The radiation source includes radiation intensity adjusting means for adjusting the radiation intensity so that the radiation intensity increases from the distal end side to the proximal end side in the mounting direction of the subject.

[0017] In addition, the invention described in claim 9 is the radiographic imaging device according to any one of claims 6 to 8!

It is characterized by comprising direction adjusting means for adjusting the direction of the radiation intensity adjusting means in accordance with the mounting direction of the subject.

[0018] Further, the invention described in claim 10 is the radiographic imaging device according to any one of claims 6 to 9,

The relative position between the radiation source and the detector holding means is fixed, and the relative position of the subject table with respect to the radiation source and the detector holding means can be changed.

[0019] In addition, the invention described in claim 11 is the radiographic imaging device according to any one of claims 6 to 10,

It is characterized in that left and right discriminating means for discriminating whether the subject held on the subject table is a left hand or a right hand is provided.

[0020] The invention according to claim 12 is the radiographic image capturing device according to any one of claims 6 to 11, A photographing direction discriminating means for discriminating the direction of the subject held on the subject table is provided.

It is characterized by being.

[0021] Further, the invention described in claim 13 is the radiographic imaging device described in claim 11 or 12!

An image data generation unit for generating image data of the phase contrast image;

Left / right information by left / right discriminating means for discriminating whether the subject held on the subject table is a left hand or a right hand, or an imaging direction discriminating unit for discriminating the direction of the subject held on the subject table. And an information ancillary means for appending at least one of the photographing direction information of the image data to the image data. The invention's effect

[0022] According to the invention described in claim 1, since the image is taken in a state in which the relative position of each joint portion of the subject is maintained substantially constant, each joint portion of the generated image is relatively The power of matching can be S. Therefore, observation diagnosis such as comparison with a radiographic image taken in the past is facilitated, and shape change of the affected part can be calculated and discriminated more accurately.

[0023] According to the invention described in claim 2, since the subject's finger is inserted along the positioning means fixed to the subject table, the degree of opening of the finger during imaging is kept constant. This makes it possible to maintain subtraction images that are easy to compare and interpret and to generate accurate subtraction images, enabling highly accurate diagnosis.

[0024] According to the invention of claim 3, since the positioning means is arranged between the fingers of the subject with the finger as the subject placed on the subject table, The relative position of the subject's fingers can be made constant, and deformation with time can be easily determined.

[0025] According to the invention described in claim 4, the subject table is set according to whether the subject is the right hand or the left hand, and the subject is positioned along the positioning means fixed to the subject table. Therefore, it is possible to keep the degree of finger opening at the time of photographing constant, and therefore it is possible to accurately determine the temporal deformation of the cartilage portion of the finger.

[0026] According to the invention of claim 5, the joint portion of the finger is photographed from a predetermined direction. Therefore, it is possible to easily determine the change with time while keeping the angle of finger photographing constant.

[0027] According to the invention described in claim 6, since the intensity of the radiation applied to the subject is adjusted according to the placement direction of the subject, the proximal end side and the distal end side in the placement direction of the subject Even when the thickness of the subject varies depending on the region, the entire subject can be irradiated with radiation having an intensity suitable for photographing.

[0028] According to the invention described in claim 7, the ends of the radiation source, the fixing means and the detector holding means near the subject are substantially straight in the irradiation direction of the radiation irradiated from the radiation source. Since the subject is placed on the radiation image detector, the subject is securely placed on the radiation image detector held by the detector holding means by capturing the subject with the fixing means. There is an effect that it is possible to take a picture without causing any trouble.

[0029] According to the invention of claim 8, the thickness of the subject, such as the tip of the finger, is thin V, and the thickness of the subject, such as the portion closer to the wrist than the portion, is thick! / Because the intensity is adjusted by the radiation intensity adjustment means so that the intensity of the radiation applied to the part is increased, even if the subject has a different thickness depending on the part, the entire subject should be irradiated with radiation suitable for imaging. There is an effect that you can.

[0030] According to the invention described in claim 9 of the present invention, since the orientation adjusting means for adjusting the orientation of the radiation intensity adjusting means according to the mounting direction is provided, the subject can be covered in any orientation. Even when placed on the camera table, the radiation intensity can be adjusted appropriately.

[0031] According to the invention described in claim 10, since the height of the apparatus can be made constant, it is preferable in terms of a general clinic or radiology building structure. In addition, the magnification ratio of the phase contrast image can be adjusted according to the size of the radiation image detector and the subject.

[0032] According to the invention described in claim 11, the left and right discriminating means discriminates whether the subject puts the hand placed on the subject table to the left or right, and the predetermined direction. Since the finger joints are photographed from the beginning, it is possible to easily determine the temporal deformation with a constant finger photographing angle. [0033] According to the invention described in claim 12, the direction of the subject's hand placed on the subject table is determined by the imaging direction determination means, and radiation is emitted from the direction corresponding to the direction. Thus, since the image is taken, it is possible to easily determine the temporal deformation with a constant finger photographing angle.

[0034] According to the invention described in claim 13, the information supplementary means and the image data generation unit can associate the image data with the supplementary information, and images are taken in the past based on the supplementary information. Observational diagnosis such as comparison with radiographic images is possible. Therefore, even if it is an easy-to-see radiological image of the left and right information and the direction of the image at first glance, it is easy to compare with the related images (radio images of the same subject taken in the past) using incidental information. The effect is that it is possible to perform accurately.

Brief Description of Drawings

FIG. 1 is a side view showing a main configuration of a radiographic image capturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing the internal configuration of the radiographic image capturing apparatus according to the first embodiment of the present invention.

[Fig. 3] Fig. 3 is a plan view when the subject places the back of the left hand facing upward on the hand holding unit in the first embodiment of the present invention.

FIG. 4 is a plan view when the subject places the palm of his left hand upward on the hand holding unit in the first embodiment of the present invention.

FIG. 5 is a plan view when the subject places his left hand on the subject table in the first embodiment of the present invention.

FIG. 6 is a plan view when the subject places his right hand on the subject table in the first embodiment of the present invention.

FIG. 7 is a block diagram showing a control configuration of the radiation image capturing apparatus according to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of the principle of phase contrast imaging.

FIG. 9 is a plan view showing a modified example of the subject table.

FIG. 10 is a plan view showing a modification of the subject table. FIG. 11 is a plan view showing a modified example of the subject table.

FIG. 12 is a side view showing a modified example of the subject table.

FIG. 13 is a front view showing a main configuration of a radiographic image capturing apparatus according to a second embodiment of the present invention.

FIG. 14 is a front view showing a main configuration of a radiographic image capturing apparatus according to a second embodiment of the present invention.

FIG. 15 is a block diagram showing a control configuration of the radiographic image capturing apparatus according to the second embodiment of the present invention.

FIG. 16 is a side view showing a configuration of a main part of a conventional mammography apparatus.

Explanation of symbols

1 Radiation imaging equipment

3 Support base

4 Camera unit

5 Support shaft

7 Holding member

8 X-ray source

9 Power supply

11 Radiation image detector

12 Detector holder

14 Subject table

15 Positioning device

16 Hand holder

17 Triangular magnet

18 Shooting direction discrimination means

19 Arm holder

19a Left arm holder

19b Right arm holder

20 Weight sensor 21 Compression plate

22 Control device

26 Informational means

27 Fixing member

28 Magnetic sensor

29 Notification means

30 Finale rotating means

H Subject

A chair

BEST MODE FOR CARRYING OUT THE INVENTION

[0037] Hereinafter, a first embodiment of a radiographic imaging apparatus according to the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

FIG. 1 shows a configuration example of the radiographic image capturing apparatus 1 in the present embodiment. In the radiographic imaging apparatus 1, a support base 3 is provided so as to be movable up and down with respect to the support base 2. On the support base 3, a substantially rectangular parallelepiped imaging device main body 4 serving as a base is supported via a support shaft 5 so as to be rotatable in the CW direction and the CCW direction. The support base 2 is provided with a driving device 6 for moving the support base 3 up and down and rotating the support shaft 5. The drive device 6 includes a known drive motor or the like (not shown). The support base 3 and the imaging device main body 4 are moved up and down according to the position of the subject H. The position of the subject H is a position near the shoulder of the subject sitting on the chair A, so that the subject can take a posture in which his / her arm is placed on the subject table 14 described later and is not fatigued. The position can be adjusted.

As shown in FIG. 2, the photographing apparatus main body 4 is provided with a holding member 7 that functions as a holding means along the vertical direction. An X-ray source 8 as a radiation source including an X-ray tube (not shown) that emits radiation (X-rays) to the subject H is attached to the upper portion of the holding member 7. A power supply unit 9 for applying a tube voltage and a tube current is connected to the X-ray source 8 via a support shaft 5, a support base 3, and an imaging apparatus main body unit 4. A diaphragm 10 for adjusting the radiation field is provided at the radiation outlet of the X-ray source 8 so as to be freely opened and closed.

[0040] The X-ray source 8 is preferably a rotary anode X-ray tube. This rotating anode X-ray tube In this case, X-rays are generated when the electron beam emitted from the cathode collides with the anode. This is incoherent (incoherent) like natural light, and is not divergent X-rays but divergent light. If the electron beam continues to hit the place where the anode is fixed, the anode will be damaged by the generation of heat. Therefore, in a normal X-ray tube, the anode is rotated to prevent a decrease in the life of the anode. The electron beam is made to collide with a certain size surface of the anode, and the generated X-rays are emitted toward the subject H from the plane of the certain size anode. This plane is called a focus. Focus size D (11 m) is the length of one side when the focus is square, the length of its short side when the focus is rectangular or polygonal, and the diameter when the focus is circular. Sure. The larger the focal spot size D, the more radiation is irradiated.

[0041] Further, the X-ray source 8 is provided with a filter 81 as a radiation intensity adjusting means for adjusting the intensity of X-rays irradiated from the X-ray tube. The filter 81 is formed of a material such as a metal that absorbs X-rays, for example, and adjusts the intensity of X-rays irradiated to the subject by adjusting the X-ray transmission dose.

[0042] The cross section of the filter 81 is formed in a substantially wedge shape so that the thickness gradually decreases from the one end side to the other end side where the one end side is thick. In the filter 81, the thicker the portion, the more X-rays are absorbed and the amount of X-ray transmitted through the filter 81 decreases, and the thinner the portion, the larger the amount of X-ray transmitted through the filter 81. Therefore, the amount of X-ray transmission can be adjusted by changing the thickness of the filter 81 depending on the portion.

[0043] The filter 81 is based on the tip side in the placement direction of the subject H whose placement direction is restricted by a triangular magnet 17 as positioning means described later (that is, the fingertip side when the subject H is a finger). It faces the holding member 7 where the thickness of the end on the subject side is thin so that the radiation intensity gradually increases toward the end side (that is, the wrist side when the subject H is a finger). It arrange | positions so that the thickness of the edge part of the side may become thick.

[0044] A radiation image detector for detecting radiation transmitted through the subject H is provided below the holding member 7.

One end of a detector holding portion 12 (detector holding means) for holding 11 is attached. Examples of the radiation image detector 11 include a cassette containing a stimulable phosphor sheet, a screen (intensifying screen) / film, and an FPD (flat panel detector). In the present embodiment, a 14 × 17 (inch) radiation image detector 11 is used. X-ray source 8 The relative position of the detector holding unit 12 is fixed, and the distance is assumed to be fixed.

[0045] A radiation dose detection unit 13 for detecting the irradiated radiation dose is provided below the holding member 7 and on the lower surface of the detector holding unit 12.

[0046] Between the X-ray source 8 and the detector holding unit 12, a flat plate-like subject table 14 that holds the subject's finger, which is the subject H, also has a lower force so that one end thereof is attached to the holding member 7. Is provided. The subject table 14 is connected to a position adjustment device 15 having a motor or the like for changing the position with respect to the holding member 7 in order to adjust the shooting magnification (position adjustment in the height direction) during phase contrast shooting.

[0047] The subject table 14 includes a right-hand placement subject table and a left-hand placement subject table, and either one is selected according to the subject and attached to the holding member 7. The imaging apparatus main body 4 has a magnetic sensor 28 as a subject table discriminating means for discriminating whether the subject table 14 is a right-hand mounting subject table or a left-hand mounting subject table. When the subject table 14 is attached, the left and right (subject table information) of the subject is discriminated.

[0048] As shown in FIGS. 3 and 4, the subject table 14 is provided with a hand holding unit 16 that holds the finger of the subject so as to intersect the radiation irradiation path. The size of the hand holding portion 16 is not particularly limited as long as the subject's fingers can be placed thereon. The upper surface of the hand holding unit 16 is provided with a triangular magnet 17 and three fixing members 27 as positioning means for keeping the position of the finger of the subject placed on the holding unit 16 constant. In this case, the finger is placed between the positioning means. Accordingly, the placement position of the finger of the subject is regulated by the triangular magnet 17 and the three fixing members 27. The size of the three fixing members 27 is not particularly limited as long as it is a size arranged between the fingers of the subject. The material of the fixing member 27 is not particularly limited, and may be a member covered with rubber or a magnet, or various metals. The hand holding unit 16 has an imaging direction discriminating means 18 for detecting the position of the triangular magnet 17 and / or the three fixing members 27 and discriminating the position of the finger of the subject's thumb as imaging information (see FIG. 7). ) Is provided.

As shown in FIGS. 5 and 6, an arm holding unit 19 that holds the arm of the subject is provided at a position closer to the subject than the hand holding unit 16 of the subject table 14. The arm holder 19 has a left arm A holding portion 19a and a right arm holding portion 19b are provided, and the subject places either the left or right arm according to the imaging conditions. The size of the arm holding part 19 is not particularly limited, but if the arm part under the subject's elbow can be placed, the finger can be fixed sufficiently stably. Depending on whether the left arm holding part 19a or the right arm holding part 19b is mounted on the left arm holding part 19a or the right arm holding part 19b, the subject's hand is the right hand or the left hand. The weight sensor 20 (see FIG. 7) is provided as a left / right discriminating means for discriminating the force (right / left information). A known sensor can be applied to the weight sensor 20 without limitation, and the number and installation positions of the weight sensors 20 provided are not particularly limited.

[0050] The subject table 14 is formed so as to protrude from the other end of the detector holding portion 12 toward the subject. Above the subject table 14, a compression plate 21 as a fixing means for pressing and fixing the subject H from above is provided so that one end thereof is attached to the holding member 7. The compression plate 21 is movable along the holding member 7 while maintaining a parallel state with the subject table 14. The movement of the compression plate 21 can be applied either automatically or manually.

The compression plate 21 and the radiation image detector 11 are arranged in the vertical direction from the X-ray source 8 in the X-ray irradiation direction. The X-ray source 8, the compression plate 21, and the radiation image detector 11 The end of the X-ray source 8 opposite to the side facing the holding member 7 (the end near the subject) and the end surface of the compression plate 21 on the subject side (the side facing the holding member 7) The opposite end, that is, the end closer to the subject, and the effective image end face on the subject side of the radiation image detector 11 (the end opposite to the side facing the holding member 7, ie, the subject) It is arranged so that it is located on a straight line. Therefore, it is preferable that an imaging target range (for example, the right hand) of the subject is arranged so as to be positioned closer to the holding member 7 than the compression plate 21 without causing image loss in the region of interest (imaging target range). In addition, it is preferable that the end surface of the subject table 14 has a curved shape so that an elderly subject having an average body shape can sit on the chair A with his / her upper body on the subject table 14. In this case, the subject can sit in the chair A and can reach the imaging position without hitting his / her legs on the detector holding section 12.

[0051] Subject table information acquired by the magnetic sensor 28, shooting direction information acquired by the shooting direction discriminating means 18, and left / right information acquired by the weight sensor 20 are added to the information via the control device 22 described later. Output to means 26. Information supplementary means 26 is generated It is also possible to associate at least one of shooting direction information and left / right information as incidental information with the image data of the phase contrast image to be recorded. The incidental information is not limited to these, and the ro information of the subject may also be incidental.

As shown in FIG. 7, the imaging device main body 4 includes a control device 22 composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). . The control device 22 includes a radiation dose detection unit 13, a power supply unit 9, a drive device 6, a magnetic sensor 28, a weight sensor 20, an imaging direction determination unit 18, a position adjustment unit 15, an information attachment unit 26, and a notification unit 29. Connected through 23. The control device 22 includes a keyboard touch panel (not shown) for inputting photographing conditions, an input device 24a including a position adjustment switch for adjusting the position of the subject table 14, and a CRT display or a liquid crystal display. An operation device 24 having a display device 24b such as a display is connected. The ROM of the control device 22 stores a control program and various processing programs for controlling each part of the radiographic image capturing device 1. The CPU cooperates with the control program and various processing programs. 1 Functions as an image data generation unit that controls the operation of each unit in an integrated manner, performs phase contrast imaging, and generates image data of a phase contrast image.

For example, the CPU controls the driving device 6 based on the determination results by the magnetic sensor 28, the weight sensor 20, and the imaging direction determination means 18, the imaging conditions of the subject, and the like, and the imaging device main unit 4 Is moved up and down to a height that matches the height of the subject, and the support shaft 5 is rotated to adjust the radiation irradiation angle. Then, the position of the subject table 14 is adjusted by the position adjusting device 15 to adjust the magnification of phase contrast imaging.

Furthermore, the CPU determines whether the hand as the subject H is inserted in the X direction toward the holding member 7 based on the determination result by the weight sensor 20 and / or the shooting direction determination means 18, and the hand is held. If it is not inserted in the X direction (see FIG. 2) toward the member 7, the notification means 29 is controlled to notify the user of the error. The notification means 29 is, for example, a sound output means for outputting a warning sound or a message, a lamp for lighting a warning light, or the like. Further, the notification means 29 may be a monitor that displays a warning or the like. In this case, for example, the display device 24b may be configured to also serve as the notification means 29. The notification means 29 is exemplified here. It is not limited to that.

Thereafter, the imaging apparatus main body 4 performs imaging processing, and the power supply unit 9 applies a tube voltage and a tube current to the X-ray source 8 to irradiate the subject H with radiation, and the radiation dose detection unit 13 When the input radiation dose reaches the preset radiation dose, the power supply unit 9 stops radiation from the X-ray source 8.

Here, the principle of phase contrast imaging will be described with reference to FIG. In phase contrast imaging, a certain distance R2 is provided between the subject H and the radiation image detector 11, so that an edge-enhanced (refractive contrast-enhanced) image resulting from refraction of radiation is obtained as shown in FIG. To get. As schematically shown in Fig. 8, radiation is refracted when passing through the object and the radiation density inside the boundary of the object becomes sparse, and the outside of the object overlaps with radiation that does not pass through the object. Density increases. In this way, the edge that is the subject boundary is enhanced as an image. This is a phenomenon resulting from the difference in refractive index between the object and air. This is an edge-enhanced image.

Further, not only the edge enhancement at the boundary between air and the subject shown in principle in FIG. 8, but also the boundary portion of the portion having a different refractive index can be obtained in the object. The subject boundary portion in the present invention can be expressed as a boundary portion with a substance having a different refractive index of radiation.

[0056] When phase contrast imaging is performed, if the distance from the X-ray source 8 to the subject H is R1, and the distance between the subject H and the radiation image detector is R2, the magnification ratio = (R1 + R2) / R1 This is a magnified shot at. For R1, the starting point is the focal point of the X-ray source 8, and the location is clearly indicated on the normal commercial X-ray source 8! /. The end point is the center line of the subject H fixed by the subject table 14 that fixes the subject position. Here, the position that is equidistant from the subject table 14 and the compression plate 21 is the center line of the subject H. For R2, the starting point is the center line of the subject H, and the ending point is the uppermost surface of the plane that receives the radiation of the radiation image detector, that is, the uppermost surface of the detector holding unit 12.

[0057] Next, the operation of this embodiment will be described.

[0058] First, based on the imaging order information and the like, either the left or right subject table 14 is selected and installed on the imaging device main body 4, and then the arm portion of the subject H as the subject H is mounted on the subject table 14. Let me put it. At this time, the triangular magnet 17 is positioned between the thumb and the index finger, and the fixing member 27 is positioned between the index finger and the middle finger, between the middle finger and the ring finger, and between the ring finger and the little finger. In this case, since the triangular magnet 17 and the fixing member 27 can be fixed without covering the subject's fingers, there is no adverse effect on photographing of the joints and bones of the fingers.

[0059] When the subject table 14 is installed in the photographing apparatus body 4, the magnetic sensor 28 determines whether the installed subject table 14 is for the right hand or the left hand.

When the wearing of the subject H is completed, the weight sensor 20 determines whether the arm portion of the subject placed on the arm holding portion 19 is left hand or right hand strength. Specifically, the determination result of whether or not the weight sensor 20 is weighted is output to the control device 22, and the control device 22 performs weighting with the weight sensor 20 provided in each of the left arm holding portion 19a and the right arm holding portion 19b. The person with the larger number of detected objects is judged to have the subject's arm. The control device 22 outputs the discrimination result to the photographing direction discrimination means 18.

[0061] After determining whether the hand placed on the subject is the left hand or the right hand, the imaging direction discriminating means 18 uses the back or palm of the subject's hand placed on the hand holding unit 16 by the imaging direction discriminating means 18. It is determined which is facing upward, and the direction of the hand as the shooting direction is determined. Specifically, the imaging direction discriminating means 18 judges the position of the finger based on the installation positions of the triangular magnet 17 and the fixing member 27 and combines it with the discrimination results obtained by the magnetic sensor 28 and the weight sensor 20 to determine the hand of the subject. Determine the direction of. The discrimination result is output to the control device 22, and an appropriate radiation irradiation angle is calculated.

In addition, the control device 22 inserts the hand, which is the subject H, in the X direction (the insertion direction of the subject H) toward the holding member 7 based on the determination result by the weight sensor 20 and the shooting direction determination unit 18. If the hand is inserted in the X direction toward the holding member 7! /, Is not! / ヽ, the notification means 29 is controlled to notify the user of the error. To do.

If there is image data obtained by radiographing the subject's fingers in the past, the left / right information and / or imaging direction information as supplementary information of the image data is extracted. A warning may be given by the display device 24b or the like. In addition, when there is no image data obtained by photographing the finger of the subject in the past, incidental information may be set in the control device 22 as one piece of photographing order information of the subject. Thereafter, the drive device 6 and the position adjustment device 15 adjust the position of the subject table 14 and the angle of the imaging device main body 4 in accordance with imaging conditions such as the radiation irradiation angle and irradiation distance. After adjusting the position and angle, the power supply unit 9 applies a predetermined tube voltage and tube current to the X-ray source 8, and the X-ray source 8 irradiates the subject H with radiation and performs imaging. When photographing is performed in this manner, the control device 22 generates image data of the phase contrast image, and the generated image data is associated with the supplementary information by the information supplementary means 26. The generated image data is preferably displayed on the display device 24b or the like after being subjected to image processing based on the acquired supplementary information and past supplementary information so as to have a layout that allows comparative interpretation.

[0064] As imaging conditions, Rl = 430 to 650 mm, R2 = 490 to 750 mm, focus size 0 = 100 ^ 111, tube voltage 30 kVp, tube current about 30 mA are preferable. In addition, the subject is preferable because either the palm or the back of the hand is directed to the X-ray source 8 side, and the visibility is improved when the palm is directed to the X-ray source 8 side. ,.

As described above, according to the radiographic imaging apparatus 1 of the present embodiment, when the subject performs radiography while placing his / her arm and arm below the subject table 14, the triangular magnet 17 and the fixing member are used. Since the position of the finger of the subject on the subject table 14 is determined by 27, the cartilage portion of the finger can be photographed while the subject is fixed without moving the finger. In addition, the relative position of the subject's fingers is maintained in a state that matches the shape of the triangular magnet 17 and the fixing member 27, so that the degree of finger opening remains constant without any difference in the relative positions of the fingers each time an image is taken. Therefore, comparative interpretation with radiographic images taken in the past is facilitated, and subtraction images based on the current and past images faithfully represent the change state of the cartilage portion, so that accurate diagnosis is possible. Can be defeated.

Further, by adjusting the X-ray intensity by the filter 81, X-rays can be irradiated with an X-ray intensity suitable for imaging even when shooting a subject having a different thickness depending on the region. Also,

In addition, since the subject can take a comfortable posture by placing his hand and arm below the elbow on the subject table 14, it is easy for the subject to easily move and move his / her fingers. It is possible to photograph the cartilage of the finger in a fixed state. [0066] Further, since the contrast between the finger and its peripheral portion in the obtained radiographic image is improved by phase contrast imaging, it is possible to easily and accurately determine whether or not the cartilage is deformed with time. In addition, since the radiographic imaging device 1 can be used to determine whether cartilage is deformed over time, it is not necessary to use a special device such as MRI, and diagnosis of rheumatic diseases can be made without burdening the subject. It is.

In addition, the magnification of the phase contrast image is adjusted by changing the position where the subject table 14 is held by the holding member 7.

[0068] Further, by providing the arm holding unit 19 with the weight sensor 20, it is possible to determine whether the hand placed on the subject table 14 by the subject is left or right. Furthermore, the direction of the subject's hand placed on the subject table 14 is determined by the imaging direction determination means 18, and the image is taken by irradiating radiation from the direction corresponding to the direction. It is possible to easily determine the temporal deformation with the constant.

[0069] When the CR force set ID is read by the imaging device as the radiation image detector 11 and the imaged force set is moved to the reading device to perform the reading process, the reading device is used together with the cassette ID. The read image data is transmitted to the control device 22, and the control device 22 associates the read image data with the accompanying information with the force set ID as a key.

[0070] When the radiation image detector 11 is an FPD, the control device 22 acquires and associates the obtained image data with the determination results by the left / right determination means and the imaging direction determination means 18 and stores them in the memory. On the contrary, the FPD obtains the discrimination result from the control device 22, stores it as supplementary information of the image data, and transmits all data (image data and supplementary information) from the FPD to the image filing device after all shooting is completed. You can do it too! /

[0071] Although the triangular magnet 17 and the three fixing members 27, 27, 27 are fixed to the subject table 14, these members may be detachably provided. In this case, the subject places the fingers on the hand holding unit 16 and the triangular magnet 17 and the fixing member 27 are arranged between the fingers, so that the finger 14 can be replaced without changing the subject 14. The ability to keep the relative position of S constant is now possible!

Alternatively, only the triangular magnet 17 may be detachable in a state where the fixing member 27 is fixed to the subject table 14. In this case, just replace the triangular magnet 17 and both It is possible to make the subject table 14 applicable to fingers.

[0073] A dedicated fixing member 27 may be provided on either the left or right finger.

[0074] In order to more securely fix the finger of the subject, the fixing member 27 is determined according to the subject in consideration of the condition of the subject such as an adult male, an adult female, a child, or a patient type. It is good to set.

[0075] Although the subject table 14 can be attached and detached and can be selected according to the subject H, only the hand holding part 16 that is a part of the subject table 14 can be attached and detached, and can be changed according to the subject H. Good as that.

[0076] Alternatively, the left / right discrimination may be performed using the force sensor that has performed the left / right discrimination using the weight sensor 20. In this case, the optical sensor emits light from the upper surface of the arm holding part 19 and detects the presence or absence of the arm part of the subject by detecting the reflection of the light from the arm part of the subject, thereby discriminating left and right. It is supposed to be.

[0077] Further, as shown in FIG. 9, the arm holding unit 19 only needs to be able to place the arm part under the subject's elbow, and only the arm holding unit 19 from the hand holding unit 16 is used. It may be protruding to the side. In that case, the arm holding portion 19 that is not in use may be moved and stored in the horizontal direction (see FIGS. 10 and 11) or in the vertical direction (see FIG. 12). Furthermore, the arm holding part 19 may be provided with a fixing belt 25 for fixing the arm part under the subject's elbow.

Further, in the present embodiment, the force radiation intensity adjusting means including the filter 81 as the radiation intensity adjusting means is arranged from the distal end side (for example, fingertip side) to the proximal end side (for example, fingertip side) of the subject H. It is sufficient that the radiation intensity of the X-rays emitted from the X-ray tube of the X-ray source 8 can be adjusted so that the radiation intensity increases toward the wrist side, and is not limited to a filter.

In addition, it goes without saying that the present invention is not limited to the above embodiment and can be modified as appropriate.

Next, a second embodiment of the radiographic image capturing apparatus according to the present invention will be described with reference to FIGS. 13 to 15. Note that the second embodiment differs from the first embodiment in the manner of adjusting the X-ray intensity by the filter 82, and therefore, the following description will particularly focus on differences from the first embodiment.

[0081] In this embodiment, the X-ray source 8 is connected from one end side to the other end side in the same manner as in the first embodiment. A filter 82 (radiation intensity adjusting means) having a substantially wedge-shaped cross section is provided so that the thickness gradually decreases toward the end. The filter 82 is set as a default in a state where the filter 82 is arranged in a direction in which the thickness becomes thicker toward the holding member 7 side along the direction orthogonal to the Y direction in FIGS. The filter 82 can be rotated by a filter rotating means 30 as an orientation adjusting means described later, and the direction of the filter 82 can be adjusted.

In the present embodiment, the subject table 14 includes a base portion that holds the subject H, and a detection unit that includes a weight sensor 20 (see FIG. 15), a triangular magnet (not shown), and the like. The detector mounting position is changed 90 degrees in the CW (or CCW) direction with respect to the mounting position in the X direction with respect to the base body, and the changed direction is detected by a sensor (not shown).

[0083] Then, the filter 82 is rotated by the filter rotating means 30 in accordance with the change in the attachment position of the detection unit, and the direction is adjusted.

That is, for example, when the subject H is inserted from the left side in the Y direction to the right side by the sensor (the weight sensor 20 is mounted so that the tip side of the subject H is located on the right side in the Y direction from the position of the triangular magnet). As shown in FIG. 13, the finer 82 is rotated by the finer rotating means 30 so that the thinner end of the filter 82 is moved to the left in the Y direction. Rotate approximately 90 degrees from the default position so that the thicker end is on the right side in the Y direction, and the direction from the left side to the right side in the Y direction, so that the thickness gradually increases. Is adjusted.

[0085] Also, for example, when the subject H is inserted from the right side in the Y direction to the left side (the weight sensor 20, the position force of the triangular magnet is placed so as to be on the left side in the direction of the tip side force of the subject H. 14), the filter 82 is rotated by the filter rotating means 30 so that the thicker end of the filter 82 is on the left side in the Y direction and the thinner one is shown in FIG. Rotate approximately 90 degrees from the default position so that the end of is on the right side in the Y direction, and the orientation is adjusted so that the thickness gradually increases toward the left side from the right side force in the Y direction.

[0086] Thereby, from the distal end side in the placement direction of the subject H (that is, the fingertip side when the subject H is a finger) to the proximal end side (that is, the wrist side when the subject H is a finger). Head Therefore, the radiation intensity can be adjusted so that the radiation intensity gradually increases.

[0087] When the attachment position of the detection unit and the orientation (rotation direction) of the filter 82 do not match, the user is warned by a notification means (not shown)! /.

[0088] Further, as shown in FIG. 7, the radiographic imaging device main unit 4 of the radiographic imaging device according to the present embodiment includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Is provided with a control device 22. The control device 22 includes a radiation dose detection unit 13, a power supply unit 9, a drive unit 6, a magnetic sensor 28, a weight sensor 20, an imaging direction determination unit 18, a position adjustment unit 15, an information supplement unit 26, a notification unit 29, A filter rotating means 30 is connected via a bus 23. The filter rotating means 30 functions as a direction adjusting means for adjusting the direction of the filter 82 as the radiation intensity adjusting means. Further, the control device 22 includes a keyboard touch panel panel (not shown) for inputting photographing conditions, an input device 24a including a position adjustment switch for adjusting the position of the subject table 14, and a CRT display or a liquid crystal display. An operation device 24 having a display device 24b such as a display is connected. The ROM of the control device 22 stores a control program and various processing programs for controlling each part of the radiographic imaging device 1, and the CPU cooperates with the control program and various processing programs in the imaging device 1 each part. It functions as an image data generation unit that controls the overall operation of the system, performs phase contrast imaging, and generates image data of a phase contrast image.

[0089] Further, the CPU determines the force with which the hand as the subject H is inserted in the X direction toward the holding member 7 based on the determination result by the weight sensor 20 and the photographing direction determination means 18, the Y direction Determine the force inserted from the left side to the right side, whether the Y direction is inserted from the right side to the left side, and determine the placement direction of the subject H placed on the subject table 14

Yes

[0090] Then, the CPU controls the filter rotating means 30 according to the placement direction of the subject regulated by a triangular magnet (not shown) as the regulating means so as to adjust the direction of the filter 82. It has become.

Note that other configurations of the radiographic image capturing apparatus 30 are the same as those shown in the first embodiment, and therefore, the same members are denoted by the same reference numerals and description thereof is omitted. Next, the operation in the present embodiment will be described.

First, based on the imaging order information, the subject places one of the left and right arms on the subject table 14 and places the triangular magnet between the thumb and the index finger.

When the subject H is placed, the weight sensor 20 determines whether the arm portion of the subject placed on the arm holding portion 19 is the left hand or the right hand. Further, the photographing direction discriminating means 18 discriminates whether the back of the subject's hand or the palm placed on the hand holding unit 16 is facing upward! /, And discriminates the direction of the hand as the photographing direction. To do.

[0095] The determination result of the weight sensor 20 and the imaging direction determination means 18 is output to the control device 22, and an appropriate radiation irradiation angle is calculated. Further, the control device 22 controls the filter rotating means 30 according to the direction in which the hand that is the subject H is inserted and from which direction! /, The force, and the placement direction of the subject H. Turn 82 to adjust the orientation.

After that, the drive device 6 and the position adjustment device 15 adjust the position of the subject table 14 and the angle of the imaging device main body 4 in accordance with the imaging conditions such as the radiation irradiation angle and the irradiation distance. After adjusting the position and angle, the power supply unit 9 applies a predetermined tube voltage and tube current to the X-ray source 8, and the X-ray source 8 irradiates the subject H with radiation and performs imaging.

As described above, according to the present embodiment, from what position the subject inserts the finger as the subject H with respect to the radiation imaging apparatus 30, and how the subject H is placed on the subject table 14 It is possible to determine whether the filter 82 is mounted in a proper direction, and to change the direction of the filter 82 according to the mounting direction of the subject H. As a result, the X-ray intensity can be appropriately adjusted by the filter 81 regardless of the direction in which the subject H is inserted and placed, and even when photographing subjects having different thicknesses depending on the part. Can be irradiated with X-ray intensity suitable for

[0098] In the present embodiment, the filter 82 is arranged in a direction in which the thickness increases in the direction closer to the holding member 7 along the direction orthogonal to the Y direction in Figs. The default position and the rotation angle of the force filter 82 described as the case where the filter rotation means 30 adjusts the direction by 90 degrees to the left and right from the default position by the filter rotation means 30 are not limited to those exemplified here. For example, the rotation angle of the filter may be adjusted with a small force according to the mounting direction of the subject H. [0099] Other than that, the present invention is not limited to the present embodiment, similar to the first embodiment.

Claims

The scope of the claims

[1] A radiation source for irradiating a subject with radiation, detector holding means for holding a radiation image detector for detecting radiation from the radiation source that has passed through the subject, the radiation source and the detector holding means, A radiographic image capturing apparatus including a subject platform arranged between and holding the subject so that a phase contrast image can be generated, wherein the subject platform has a fixed relative position of each joint portion of the subject. A radiographic imaging device comprising positioning means for maintaining the position.

2. The radiographic imaging device according to claim 1, wherein the positioning means is fixed to the subject table.

[3] The radiographic imaging device according to claim 1, wherein the positioning means is detachably provided.

[4] The radiographic imaging device according to claim 1 or 2, wherein the subject table is a right-hand subject table and a left-hand subject table, and is detachably provided. .

5. The radiographic imaging according to claim 4, further comprising a subject base discriminating means for discriminating whether the subject base is a right hand subject base or a left hand subject base. apparatus.

[6] The positioning means regulates the subject in the placement direction,

2. The radiographic image capturing apparatus according to claim 1, wherein the radiation source irradiates the radiation by changing a radiation intensity according to a placement direction of the subject regulated by the positioning unit.

[7] holding means for holding the radiation source, the object table, and the detector holding means so that a phase contrast image can be generated;

Fixing means for fixing the subject to the subject table,

The radiation source, the fixing means, and the detector holding means are arranged so that the end portion close to the subject is positioned almost on a straight line in the irradiation direction of the radiation emitted from the radiation source. 7. The radiographic image capturing device according to claim 6, wherein the radiographic image capturing device is provided.

[8] The radiation source includes radiation intensity adjusting means for adjusting the radiation intensity so that the radiation intensity increases from the distal end side to the proximal end side in the mounting direction of the subject. The radiographic imaging device according to claim 6 or 7.

[9] The apparatus according to any one of claims 6 to 8, further comprising direction adjusting means for adjusting the direction of the radiation intensity adjusting means according to the mounting direction of the subject! /, Radiation imaging device according to item 1 above.

[10] The relative position between the radiation source and the detector holding means is fixed, and the relative position of the subject table with respect to the radiation source and the detector holding means can be changed. The radiographic image capturing device according to any one of Items 6 to 9 in the range.

11. The left and right discrimination means for judging whether the subject held on the subject table is a left hand or a right hand is provided. V, Radiation imaging apparatus according to item 1 above.

[12] The shooting direction discriminating means for discriminating the orientation of the subject held on the subject table is provided. The radiographic imaging device described in one item.

[13] An image data generation unit that generates image data of the phase contrast image;

Left / right information by left / right discriminating means for discriminating whether the subject held on the subject table is a left hand or a right hand, or an imaging direction discriminating unit for discriminating the direction of the subject held on the subject table. 13. The radiographic image capturing apparatus according to claim 11, further comprising: an information appending unit that appends at least one of the imaging direction information by the image data to the image data.