JPWO2017026046A1 - Bone density measuring device - Google Patents

Abstract

The bone density measuring apparatus of the present invention includes a fixture that adjustably fixes the angle of the leg of the subject with respect to the X-ray imaging system, and inputs the internal rotation angle as the angle of the leg to the internal rotation angle registration item 13a. And register for the next inspection. In addition, the examination history information having an internal rotation angle is stored, and the examination history information corresponding to the subject to be examined at the time of the examination is read out and output, thereby retrieving the past examination history information at the time of the examination. Provide for inspection. Since each examination history information is stored corresponding to each subject, the internal rotation angle corresponding to the subject to be examined can be searched together with the examination history information. As a result, the leg can be positioned at the same internal rotation angle in the examination of the same subject, and the reproducibility of the examination by imaging is improved in the leg.

Description

  The present invention relates to a bone density measuring apparatus that measures bone density by X-ray imaging.

  In X-ray imaging of a leg of a subject, measurement using an X-ray beam having two different energy peaks, for example, a DXA (Dual Energy X-Ray Absorptiometry) method is performed (see, for example, Patent Document 1). Specifically, the subject (patient) is laid on the top and the leg is rotated inward so that X-rays are incident perpendicularly to the proximal femur. An X-ray beam having two different energy peaks generates an image photographed under a high voltage condition and an image photographed under a low voltage condition, and obtains a difference between them to generate a subtraction image. Only the femur is selectively shown inside.

  By this DXA method, bone density such as bone mineral density can be obtained which is an index indicating the amount of mineral contained in a certain amount of bone (such as calcium and phosphorus). In order to accurately obtain the bone density such as bone mineral content determination, as described above, positioning (positioning) is performed in which the leg is internally rotated so that X-rays are perpendicularly incident on the proximal femur. In positioning, the purpose of photographing can be accurately performed by using a dedicated fixing device that fixes the leg portion inward with the heel as a center.

JP 2012-254191 A

  However, since the conventional fixture has a fixed leg angle (hereinafter referred to as “internal rotation angle”), the conventional device for bone density measurement records the internal rotation angle of the leg for each subject. There is no mechanism to do this.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bone density measuring device that improves the reproducibility of examination by photographing at the leg.

  As a result of earnest research to solve the above problems, the inventors have obtained the following knowledge.

  In other words, a fixture that fixes a leg portion at a typical internal rotation angle has been conventionally used. In practice, the appropriate internal rotation angle varies depending on the subject. Accordingly, the present applicant has proposed a fixture that can be fixed at an arbitrary angle. Periodic follow-up is important in bone density testing, and high reproducibility is required. By using the above-described arbitrary angle fixing tool, it is possible to perform a bone density test with more appropriate positioning. In the examination of the same subject, it was found that it is necessary to perform positioning at the same angle every time from the viewpoint of improving reproducibility.

  In addition, when positioning at the same angle every time in the examination of the same subject, the surgeon memorizes each internal rotation angle using an appropriate remarks column or memo and makes it for the next examination. It is necessary to prepare. Therefore, a registration means for registering the angle of the leg portion or a storage means for storing examination history information having the angle of the leg portion, corresponding to the subject to be examined at the time of examination from the storage means at the time of examination. It was also found that if the inspection history information is read and output, it is possible to save the trouble of storing individual internal rotation angles using appropriate remarks columns and memos.

The present invention based on such knowledge has the following configuration.
That is, the bone density measuring apparatus (the former) of the present invention is a bone density measuring apparatus that measures bone density by X-ray imaging, and fixes the angle of the leg of the subject relative to the X-ray imaging system so as to be adjustable. It comprises a fixture and a registration means for registering the angle of the leg.

  According to the bone density measuring apparatus (the former) of this invention, the fixture for fixing the angle of the leg portion of the subject relative to the X-ray imaging system is provided, and the angle of the leg portion is registered so that the next examination can be performed. Provide. As a result, the leg can be positioned at the same angle in the examination of the same subject, and the reproducibility of the examination by imaging at the leg is improved.

  The bone density measuring device (the latter) of the invention different from the former is a bone density measuring device that measures bone density by X-ray imaging, and adjusts the angle of the leg of the subject with respect to the X-ray imaging system. A fixture that can be fixed, storage means for storing examination history information having the angle of the leg, and reading out the examination history information corresponding to the subject to be examined at the time of examination from the storage means Output control means for outputting.

  According to the bone density measuring device (the latter) of the present invention, similarly to the bone density measuring device of the former invention, the bone density measuring device includes a fixture for fixing the angle of the leg portion of the subject with respect to the X-ray imaging system in an adjustable manner. The past inspection history information is read (that is, retrieved) and used for the next inspection. In addition, since each examination history information is stored corresponding to each subject, the angle of the leg corresponding to the subject to be examined can be read (searched) together with the examination history information. As a result, the leg can be positioned at the same angle in the examination of the same subject, and the reproducibility of the examination by imaging at the leg is improved.

  The bone density measuring device of the latter invention may be provided with a registration means for registering the angle of the leg portion, as in the bone density measuring device of the former invention. That is, the registered angle of the leg is stored as examination history information in the storage means for each subject.

  Further, when the registration means in the bone density measuring device of the former invention and the registration means in the bone density measuring device of the latter invention are provided, the registration means is an input means, and the input means You may enter and register an angle. An operator can manually register the angle of the leg by inputting the angle. Of course, the registration means may be constituted by calculation means such as a central processing unit (CPU), and the registration means may receive and automatically register the leg angle by the angle sensor (tilt angle sensor). Further, both manual registration and automatic registration may be incorporated.

  Moreover, an example of the angle of the leg in the bone density measuring device of the former invention and the bone density measuring device of the latter invention is the internal rotation angle of the leg. In addition, the angle of the leg may be an angle formed by the neck of the femur and the femur axis (referred to as “cervical angle”).

  Further, in the bone density measuring device of the former invention and the bone density measuring device of the latter invention, a subtraction image is generated by acquiring a difference between an image photographed under a high voltage condition and an image photographed under a low voltage condition. The image generation means may be provided. When the image generation means for generating the subtraction image is provided, only the femur is selectively displayed in the subtraction image, and therefore, it is used for bone density measurement for obtaining bone density such as bone mineral density determination. In particular, there is a close correlation between bone density and leg angle (for example, internal rotation angle), and it is useful to apply to an apparatus having an image generating means for generating a subtraction image (that is, performing subtraction). . You may apply to the other general bone density measuring apparatus (it does not perform subtraction) other than that.

According to the bone density measuring apparatus (the former) according to the present invention, a fixture for fixing the angle of the leg of the subject relative to the X-ray imaging system is provided, and the next examination is performed by registering the angle of the leg. To serve. As a result, the reproducibility of inspection by photographing at the leg is improved.
In addition, according to the bone density measuring device (the latter) according to the invention of the invention different from the former, the bone density measuring apparatus (the latter) is provided with a fixture for fixing the angle of the leg of the subject relative to the X-ray imaging system, Since the information is stored corresponding to each subject, the angle of the leg corresponding to the subject to be examined can be read (searched) together with the examination history information. As a result, the reproducibility of inspection by photographing at the leg is improved.

It is a block diagram of the bone mineral density measuring device which concerns on an Example. (A)-(c) is a perspective view of the whole structure of a fixing tool. It is a perspective view of the angle meter of a fixture. It is a side view of the fixing belt of a fixing tool. It is the aspect of registration of the internal rotation angle by an input part. It is a schematic diagram of the femur regarding the neck angle. It is a block diagram of the bone density measuring device concerning a modification.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a bone density measuring apparatus according to an embodiment. FIGS. 2A to 2C are perspective views of the overall configuration of the fixture, and FIG. 3 is an angle of the fixture. FIG. 4 is a side view of the fixing belt of the fixture. In the present embodiment, a bone density measuring device that performs subtraction by the DXA method will be described as an example, and an internal rotation angle of the leg portion will be described as an example of the leg portion angle.

  As shown in FIG. 1, the bone density measuring apparatus includes a top plate 1 on which a subject M is placed, an X-ray tube 2 that irradiates the subject M with X-rays, and an X that passes through the subject M. A flat panel X-ray detector (hereinafter abbreviated as “FPD”) 3 for detecting a line. Two types of filters 21 for high-voltage mode and low-voltage mode are provided on the irradiation side of the X-ray tube 2, and the X-ray beams having two different energy peaks are respectively irradiated by switching the filter 21.

  In addition, the bone density measuring device also includes the top plate control unit 4 that controls the elevation and horizontal movement of the top plate 1, the FPD control unit 5 that controls the scanning of the FPD 3, and the tube voltage and tube current of the X-ray tube 2. An X-ray tube control unit 7 having a high voltage generation unit 6 to be generated, an A / D converter 8 that digitizes and extracts an X-ray detection signal that is a charge signal from the FPD 3, and an A / D converter 8 An image generation unit 9 that generates a subtraction image based on an X-ray detection signal, a controller 10 that controls these components, a generated subtraction image, examination history information for each subject M to be described later, and the like are stored. A memory unit 11, an input unit 12 for an operator to make input settings, a monitor 13 for displaying processed images, and the like are provided. The image generation unit 9 corresponds to the image generation unit in the present invention, the controller 10 corresponds to the output control unit in the present invention, and the input unit 12 corresponds to the input unit in the present invention. The input unit 12 also corresponds to a registration unit in the present invention.

  The top board control unit 4 horizontally moves the top board 1 to accommodate the subject M up to the imaging position, or moves the top board 1 up and down, rotates and horizontally moves the subject M to a desired position. For example, control is performed to move horizontally from the shooting position. These controls are performed by controlling a top plate drive mechanism (not shown) including a motor and an encoder (not shown).

  The FPD control unit 5 performs control such that the FPD 3 is moved horizontally to be accommodated up to the imaging position facing the X-ray tube 2 or moved horizontally after the imaging is completed to be retracted from the imaging position. These controls are performed by controlling an FPD drive mechanism (not shown) including a rack, pinion, motor, encoder (not shown), and the like.

  The high voltage generator 6 generates a tube voltage and a tube current for irradiating X-rays, and gives them to the X-ray tube 2. The X-ray tube control unit 7 performs control such that the X-ray tube 2 is moved horizontally to be accommodated up to the imaging position facing the FPD 3 or moved horizontally after the imaging is completed and retracted from the imaging position. These controls are performed by controlling an X-ray tube driving unit (not shown) including a column, a screw rod, a motor, an encoder (not shown), and the like. In addition, the X-ray tube control unit 7 performs control to switch the filter 21. This control is performed by controlling a filter driving unit (not shown) including, for example, a rotary table (not shown).

  The controller 10 is configured by a central processing unit (CPU) and the like, and the memory unit 11 is configured by a storage medium represented by ROM (Read-only Memory), RAM (Random-Access Memory), and the like. Yes. The input unit 12 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, and the like. Similarly to the controller 10, the top panel control unit 4, the FPD control unit 5, and the X-ray tube control unit 7 are also configured by a CPU or the like.

  In the present embodiment, the controller 10 reads out and outputs the examination history information corresponding to the subject M that is the subject of the examination from the examination history information memory unit 11a of the memory unit 11 at the time of the examination. In the present embodiment, the controller 10 performs control so that the inspection history information is output and displayed on the monitor 13.

  In the present embodiment, the memory unit 11 includes an inspection history information memory unit 11a that stores inspection history information having the internal rotation angle of the leg. In this embodiment, the internal rotation angle registered by the input unit 12 is stored for each subject M in the examination history information memory unit 11a as examination history information. Examination history information other than the internal rotation angle includes, for example, examination date and time, imaging conditions, and subject information (name, date of birth, etc.). The inspection history information memory unit 11a corresponds to the storage means in this invention.

  In this embodiment, the input unit 12 is configured to input and register an internal rotation angle. The registration of the internal rotation angle by the input unit 12 will be described later in detail.

  The image generation unit 9 transmits an image photographed under a high voltage condition based on an X-ray detection signal transmitted through the high voltage mode filter 21 and transmitted through the low voltage mode filter 21. A difference from an image taken under a low voltage condition based on the X-ray detection signal is acquired. The difference image acquired in this way is generated as a subtraction image. The image generation unit 9 includes a subtractor.

  Based on the subtraction image generated in this way, bone density such as bone mineral content is determined. As described in the knowledge in the section “Means for Solving the Problems”, in order to accurately obtain the bone density, a fixing tool 30 having an arbitrary angle shown in FIGS. 2 to 4 (see also FIG. 1) is used. This makes it possible to perform a bone density test with more appropriate positioning. As shown in FIGS. 2 (a) to 2 (c), the fixture 30 includes two substrates 31 and a plate-like fixing member 32 that face the top plate 1 (see FIG. 1) of the bone density measuring device. The structure is coupled by a hinge 33. Since the hinge 33 is interposed between the substrate 31 and the fixing member 32, the fixing member 32 can rotate with respect to the substrate 31. The fixing tool 30 corresponds to the fixing tool in the present invention.

  The substrate 31 is a rectangular plate-shaped member. The fixing member 32 is a plate that is fixed to the foot portion (portion from the ankle to the toe) of the subject M (see FIG. 1) placed on the top plate 1. The fixing member 32 is also a rectangular plate-like member, and has a configuration in which one side in the longitudinal direction (the bottom side in FIGS. 2A and 2B) is attached to the hinge 33. The one side of the fixing member 32 is parallel to the rotation axis of the hinge 33. The hinge 33 is a member that connects the substrate 31 and the fixing member 32.

  The hinge 33 is a torque hinge. Therefore, when the fixing member 32 is tilted to a certain angle, the hinge 33 maintains this tilt angle against gravity. Accordingly, the hinge 33 does not change the inclination of the fixing member 32 until the operator applies a force to the fixing member 32. As described above, the hinge 33 is configured to maintain the inclination angle of the fixing member 32 with respect to the substrate 31.

  On the other side (the upper side in FIGS. 2 (a) and 2 (b)) opposite to the one side (the bottom side in FIGS. 2 (a) and 2 (b)) attached to the hinge 33 of the fixing member 32 As shown in FIG. 2A, an operator's handle 34 is attached. The operator can rotate the fixing member 32 using the handle 34 as a clue.

  FIG. 2B illustrates a state when the fixing member 32 in the state of FIG. 2A is rotated with respect to the substrate 31, and FIG. The state when the fixing member 32 is rotated to the position where the fixing member 32 becomes parallel is illustrated. The hinge 33 at this time is folded and moved to a position where the two blade pieces are sandwiched between the substrate 31 and the fixing member 32. Then, the other side of the fixing member 32 opposite to the side on which the hinge 33 is provided protrudes from the substrate 31. Thus, the hinge 33 of the fixture 30 can be tilted until the fixing member 32 is parallel to the substrate 31. 2B and 2C, the handle 34 is not shown.

  As shown in FIGS. 2A to 2C, the substrate 31 and the fixing member 32 are provided with cushion plates 35 and 36 each having a rectangular shape. The cushion plate 36 is provided so as to cover the surface of the fixing member 32 opposite to the surface on which the hinge 33 is provided, and the cushion plate 35 is disposed on the substrate 31 as shown in FIG. When the fixing member 32 is rotated to a position where the fixing member 32 becomes parallel, it is provided so as to cover the upper surface of the substrate 31 facing upward in the vertical direction while avoiding the portion hidden behind the fixing member 32 and invisible. A portion where the cushion plate 35 is provided coincides with a portion which serves as an underlay of the foot portion of the substrate 31 and supports the lower side of the foot portion.

  The cushion plates 35 and 36 are made of a member having cushioning properties. When a part of the cushion plates 35 and 36 is pressed with a finger, the pressed part is deformed so as to be depressed, and a repulsive force to push the finger back is applied. When the finger is released from the cushion plates 35 and 36, the depression of the pressed portion disappears, and the state before being pressed with the finger is restored. The surface of the substrate 31 and the fixing member 32 on which the cushion plates 35 and 36 are provided is the surface on the foot side of the subject as shown in FIG.

  Although not shown in FIGS. 2 (a) to 2 (c), the fixture 30 (see FIG. 2) has a fixing member 32 (see FIG. 2) for the substrate 31 (see FIG. 2). 2) (see FIG. 2). As shown in FIG. 3, the goniometer has a fan-shaped protractor 37 provided so as to cover the hinge 33 (see FIG. 2) from the outside, and a mark 38 indicating the angle on the protractor 37. The protractor 37 is provided at both ends of the substrate 31 and is integrated with the substrate 31. The marks 38 are provided at both ends of the surface of the fixing member 32 where the blade pieces of the hinge 33 are provided. Therefore, the fixture 30 has two angle meters shown in FIG. 3 at both ends.

  When the fixing member 32 is tilted with respect to the substrate 31, the mark 38 moves following the fixing member 32, so that the positional relationship between the mark 38 and the protractor 37 changes. The angle on the protractor 37 indicated by the arrow attached to the mark 38 coincides with the inclination angle of the fixing member 32 with respect to the substrate 31.

  Although not shown in FIGS. 2 and 3, the fixture 30 fixes the subject's foot by integrating the subject's foot and the fixing member 32 as shown in FIG. A fixing belt 39 that is fixed to the member 32 is provided. The fixing belt 39 is formed of a ring-shaped member made of a contractible material. The fixing belt 39 collectively surrounds the foot portion of the subject and the fixing member 32. Since the fixing belt 39 has contractibility, the fixing belt 39 tends to be contracted while surrounding the foot portion of the subject and the fixing member 32. Then, a force for integrating the foot portion of the subject and the fixing member 32 is applied to both. Thus, the foot portion of the subject is fixed to the fixing member 32. When the fixing member 32 is tilted with respect to the substrate 31 in this state, the foot portion of the subject tilts following this. By removing the fixing belt 39 from the main body of the fixing tool 30, the foot portion of the subject can be separated from the fixing member 32.

  At this time, the side portion of the subject's foot where the thumb is located is in contact with the cushion plate 36 having cushioning properties, and is not in direct contact with the hard fixing member 32. In addition, the heel at the foot of the subject contacts the cushion plate 35 having cushioning properties, and does not directly contact the hard substrate 31.

  When performing bone density measurement by X-ray imaging, first, the top plate 1 (see FIG. 1) is faced so that the fixing member 32 of the fixture 30 shown in FIGS. Then, the substrate 31 is placed. Then, the subject M (see FIG. 1) is placed on the top plate 1, and the heel is brought into contact with the cushion plate 35 as shown in FIG. At the same time, the side surface of the foot portion on the side where the thumb is located is brought into contact with the cushion plate 36. In this state, the foot is fixed to the fixing member 32 by the fixing belt 39.

  The surgeon moves the X-ray tube 2 and the FPD 3 (see FIG. 1) to the imaging position of the hip joint. X-rays having a dose lower than that of X-ray imaging are emitted from the X-ray tube 2 and a fluoroscopic image in which the hip joint is reflected is displayed in real time. When the surgeon moves the X-ray tube 2 and the FPD 3 with respect to the subject M while confirming the fluoroscopic image, the image reflected on the fluoroscopic image moves following the movement. In this way, the operator can adjust the position so that the femoral head related to bone mineral content determination is near the center of the field of view.

  After the adjustment of the position of the femur, the real-time imaging of the fluoroscopic image is stopped. The operator holds the handle 34 in FIG. 2A and rotates the fixing member 32 to an angle (internal rotation angle) where X-rays are perpendicularly incident on the proximal femur. Following the rotation of the fixing member 32, the leg portion rotates inward (ie, internal rotation) around the heel. As described in the knowledge in the section “Means for Solving the Problem”, an appropriate internal rotation angle varies depending on the subject M.

  When a bone density measurement test has been performed on the same subject M in the past, the test history information corresponding to the subject M to be tested from the test history information memory unit 11a (see FIG. 1). And the controller 10 (see FIG. 1) controls to output and display the examination history information on the monitor 13 (see FIG. 1). Since the examination history information has the internal rotation angle of the leg, the internal rotation angle corresponding to the subject M to be examined is also output and displayed on the monitor 13.

  The surgeon confirms the internal rotation angle output and displayed on, for example, an inspection start screen (not shown) of the monitor 13 and performs positioning. Specifically, after confirming the internal rotation angle of the examination start screen on the monitor 13, the surgeon matches the angle on the protractor 37 indicated by the arrow attached to the mark 38 in FIG. 3. Until the fixing member 32 is rotated. When the fixing member 32 is rotated until it matches the internal rotation angle, the positioning is finished.

  On the other hand, when the bone density measurement test has not been performed on the same subject M in the past, the internal rotation angle is registered by the input unit 12 (see FIG. 1) at the time of positioning. For this purpose, the operator rotates the fixing member 32 so that the knee of the subject M faces vertically upward. Then, positioning ends. The angle on the protractor 37 indicated by the arrow attached to the mark 38 at that time coincides with the internal rotation angle to be registered.

  Registration of the internal rotation angle by the input unit 12 (see FIG. 1) will be described with reference to FIG. FIG. 5 shows a mode of registration of the internal rotation angle by the input unit.

  As shown in FIG. 5, an internal rotation angle registration item 13a for registering (storing) an internal rotation angle is provided, for example, on the analysis screen 13A of the monitor 13 (see also FIG. 1). In addition, it is preferable to provide a subject registration item 13b for registering (storing) an identification number or identifier (symbol or character) for each subject. In addition, as examination history information other than the internal rotation angle, for example, items (not shown) for registering (storing) examination date and time, imaging conditions, subject information (such as name and date of birth), and the like may be provided.

  The surgeon confirms the angle on the protractor 37 indicated by the arrow attached to the mark 38 in FIG. 3 as an internal rotation angle, and the internal rotation angle is registered by the input unit 12 (see FIG. 1) as an internal rotation angle registration item 13a. Enter in to register. For example, the input button 13c is displayed on the analysis screen 13A, the pointer is aligned with the input button 13c by the pointing device of the input unit 12, and the surgeon clicks the input button 13c to register the internal rotation angle by the input unit 12. I do. In addition, the input button may be configured by the input unit 12, and the internal rotation angle may be registered by the input unit 12 when the surgeon presses the input button. Further, by configuring the monitor 13 as a touch panel, the touch panel may also serve as the function of the input unit 12, and the operator may register the internal rotation angle by the input unit 12 by touching an input button of the touch panel.

  At this time, when the subject registration item 13b is provided, the identification number or identifier of the subject is input to the subject registration item 13b by the input unit 12 and registered. Each time the internal rotation angle is registered, the identification number or identifier of the subject and the internal rotation angle are associated with each other and written in the inspection history information memory unit 11a (see FIG. 1) as inspection history information for each subject. Remember me. For the next bone density measurement test, the test history information corresponding to the subject M to be tested is read from the test history information memory unit 11a and output and displayed on the test start screen on the monitor 13.

  Returning to the description of FIG. After the positioning is completed, when the operator gives an X-ray imaging instruction to the X-ray tube control unit 7 via the input unit 12 and the controller 10, X-rays with a dose stronger than the fluoroscopic image are emitted from the X-ray tube 2. Irradiate. The high voltage mode filter and the low voltage mode filter 21 are switched to each other, and the X-rays transmitted through the filter 21 from the X-ray tube 2 are respectively irradiated.

  The FPD 3 detects X-rays that have passed through the high-voltage mode filter 21, sends the image to the image generation unit 9 as an image photographed under a high-voltage condition via the A / D converter 8, and for the low-voltage mode X-rays transmitted through the filter 21 are detected and sent to the image generation unit 9 as an image photographed under a low voltage condition via the A / D converter 8. The image generation unit 9 generates a subtraction image by acquiring a difference between an image shot under a high voltage condition and an image shot under a low voltage condition. Bone density such as bone mineral density is determined based on the subtraction image that selectively shows only the femur.

  The bone density measuring apparatus according to the present embodiment includes the fixture 30 that adjustably fixes the angle of the leg portion of the subject M with respect to the X-ray imaging system, and the leg angle (in this embodiment, the leg portion). (Internal rotation angle) is registered and used for the next inspection. As a result, the leg can be positioned at the same angle (inner rotation angle) in the examination of the same subject M, and the reproducibility of the examination by imaging is improved in the leg.

  In the present embodiment, the storage means (inspection history information memory section 11a in the present embodiment) that stores the inspection history information having the angle of the leg (inner rotation angle) and the storage means (inspection history information in the present embodiment). An output control means (controller 10 in this embodiment) that reads out and outputs (displays on the monitor 13 in this embodiment) the examination history information corresponding to the subject M to be examined from the memory unit 11a). I have. The past inspection history information is read (that is, searched) at the time of inspection and used for the next inspection. Further, since each examination history information is stored corresponding to each subject M, the leg angle (inner rotation angle) corresponding to the subject M to be examined is read together with the examination history information ( Search). As a result, the leg can be positioned at the same angle (inner rotation angle) in the examination of the same subject M, and the reproducibility of the examination by imaging is improved in the leg.

  In the present embodiment, the registered angle (inner rotation angle) is stored for each subject M in the storage means (examination history information memory unit 11a) as examination history information.

  In the present embodiment, the registration means is an input means (input section 12 in the present embodiment), and the leg angle (inner rotation angle) is input and registered by the input means (input section 12). The operator can input and manually register the leg angle (inner rotation angle) by the input means (input unit 12). In this embodiment, the angle of the leg is the internal rotation angle of the leg.

  In this embodiment, image generation means (image generation unit 9 in this embodiment) is provided that acquires a difference between an image shot under a high voltage condition and an image shot under a low voltage condition to generate a subtraction image. ing. When the image generation means (image generation unit 9) for generating a subtraction image is provided as in the present embodiment, only the femur is selectively displayed in the subtraction image. Used for density measurement. In particular, there is a close correlation between the bone density and the leg angle (for example, the internal rotation angle as in the present embodiment), and an image generation unit (image generation unit 9) that generates a subtraction image is provided (that is, subtraction). It is useful to apply to an apparatus.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In the above-described embodiment, the bone density measuring device has been described taking the example of a device that performs subtraction by the DXA method, but may be applied to a general bone density measuring device that does not perform subtraction.

  (2) In the above-described embodiment, examination history information having the angle of the subject's leg (in the embodiment, the internal rotation angle of the leg) is read and output, and is output and displayed on the monitor 13 of FIG. However, output printing may be performed on a printer (not shown).

  (3) In the above-described embodiment, the internal rotation angle of the leg is taken as an example of the leg angle of the subject. However, the internal rotation angle of the leg is not limited as long as the angle is the leg. For example, the angle of the leg may be an angle (cervical body angle) θ formed by the neck axis A and the femoral axis B of the femur as shown in FIG. When the cervical angle is larger than normal, the femur extends outward and becomes a varus crotch, and when the cervical angle is smaller than normal, the femur extends inward and becomes a varus crotch. Bone mineral content is appropriately determined when the femur is straight without valgus or varus. When confirming the cervical body angle, for example, a fluoroscopic image in which the femur is reflected is displayed in real time, and the operator fixes the leg portion of the subject so that the femur extends straight (not shown). To obtain an image in a state where the femur is stretched straight. Then, the cervical angle is registered based on the measurement result of the cervical angle from the image.

  (4) In the embodiment described above, the angle of the leg (in the embodiment, the internal rotation angle of the leg) is input and registered manually by the input means (in the embodiment, the input unit 12), but the central processing unit ( The registration unit may be configured by a calculation unit such as a CPU, and the registration unit may receive and automatically register an angle (inner rotation angle) by an angle sensor (tilt angle sensor). For example, as shown in FIG. 7, an angle sensor 40 made of a magnetic sensor is provided on the side surface of the fixing member 32 (see FIGS. 2 and 4) and the cushion plate 36 (see FIGS. 2 and 4) of the fixture 30. The calculation means is constituted by the controller 10, and the controller 10 receives the angle (inner rotation angle) by the angle sensor 40 and automatically registers it. Further, both manual registration and automatic registration may be incorporated.

  (5) In the embodiment described above, the registration unit (in the embodiment, the input unit 12) for registering the angle of the leg of the subject (in the embodiment, the internal rotation angle of the leg) is provided and the angle (internal rotation angle). ) Corresponding to the subject to be examined at the time of examination from the storage means (examination history information memory unit 11a) at the time of examination. Output control means (controller 10 in the embodiment) that reads and outputs the inspection history information, but registers the leg angle (inner rotation angle) and registers the registered leg angle (inner rotation angle). ) May be displayed as a list or printed as a list regardless of the subject to be examined.

  (6) In the embodiment described above, the registration unit (in the embodiment, the input unit 12) for registering the angle of the leg of the subject (in the embodiment, the internal rotation angle of the leg) is provided, and the angle (internal rotation angle). ) Corresponding to the subject to be examined at the time of examination from the storage means (examination history information memory unit 11a) at the time of examination. Output control means (controller 10 in the embodiment) for reading and outputting the inspection history information, but the inspection history information having the leg angle (internal rotation angle) registered in the external device is measured for bone density The data is stored in the storage unit (examination history information memory unit 11a) of the apparatus, and the examination history information corresponding to the subject to be examined at the time of examination is read out from the storage unit (examination history information memory unit 11a) and output. Shi It may be.

  As described above, the present invention is suitable for a bone density measuring apparatus that performs subtraction by the DXA method.

DESCRIPTION OF SYMBOLS 9 ... Image generation part 10 ... Controller 11a ... Examination history information memory part 12 ... Input part 13 ... Monitor 13A ... Analysis screen 13a ... Subject registration item 30 ... Fixture M ... Subject

The present invention based on such knowledge has the following configuration.
That is, the bone density measuring apparatus (the former) of the present invention is a bone density measuring apparatus that measures bone density by X-ray imaging, and fixes the angle of the leg of the subject relative to the X-ray imaging system so as to be adjustable. It is characterized by comprising a fixing tool and a registration means for registering the angle of the leg arbitrarily determined by the surgeon .

According to the bone density measuring apparatus (the former) of the present invention, the bone density measuring apparatus (the former) is provided with a fixture for fixing the angle of the subject's leg relative to the X-ray imaging system, and the leg angle arbitrarily determined by the operator is registered. This will be used for the next inspection. As a result, the leg can be positioned at the same angle in the examination of the same subject, and the reproducibility of the examination by imaging at the leg is improved.

The bone density measuring device (the latter) of the invention different from the former is a bone density measuring device that measures bone density by X-ray imaging, and adjusts the angle of the leg of the subject with respect to the X-ray imaging system. Corresponding to a fixture that can be fixed, storage means for storing examination history information having the angle of the leg arbitrarily determined by the surgeon, and a subject to be examined at the time of examination from the storage means at the time of examination Output control means for reading and outputting the inspection history information.

According to the bone density measuring device (the latter) of the present invention, similarly to the bone density measuring device of the former invention, the bone density measuring device includes a fixture for fixing the angle of the leg portion of the subject with respect to the X-ray imaging system in an adjustable manner. The past inspection history information is read (that is, retrieved) and used for the next inspection. Note that the examination history information has a leg angle arbitrarily determined by the operator. In addition, since each examination history information is stored corresponding to each subject, the angle of the leg corresponding to the subject to be examined at the time of the examination (optionally determined by the operator) together with the examination history information Can be read (searched). As a result, the leg can be positioned at the same angle in the examination of the same subject, and the reproducibility of the examination by imaging at the leg is improved.

According to the bone density measuring apparatus (the former) according to the present invention, the bone density measuring apparatus (the former) is provided with a fixture for fixing the angle of the subject's leg relative to the X-ray imaging system so that the angle of the leg can be determined arbitrarily by the operator. Register for the next inspection. As a result, the reproducibility of inspection by photographing at the leg is improved.
Further, according to the bone density measuring apparatus (the latter) according to the invention of the invention different from the former, the bone density measuring apparatus (the latter) includes a fixture for fixing the angle of the leg of the subject relative to the X-ray imaging system, and the examination history information is The angle of the leg determined arbitrarily by the surgeon and each examination history information is stored corresponding to each subject, so that it corresponds to the subject to be examined (the surgeon The angle of the leg ( which is arbitrarily determined ) can be read (searched) together with the inspection history information. As a result, the reproducibility of inspection by photographing at the leg is improved.

Claims (9)

A bone density measuring device for measuring bone density by radiography,
A fixture that adjustably fixes the angle of the leg of the subject relative to the X-ray imaging system;
A bone density measuring apparatus comprising: a registration unit that registers an angle of the leg. The bone density measuring device according to claim 1,
The registration means is an input means,
A bone density measuring apparatus characterized in that an angle of the leg is input and registered by the input means. In the bone density measuring device according to claim 1 or 2,
The bone density measuring device according to claim 1, wherein the angle of the leg is an internal rotation angle of the leg. In the bone density measuring apparatus in any one of Claims 1-3,
An apparatus for measuring bone density, comprising: an image generating means for acquiring a difference between an image photographed under a high voltage condition and an image photographed under a low voltage condition to generate a subtraction image. A bone density measuring device for measuring bone density by radiography,
A fixture that adjustably fixes the angle of the leg of the subject relative to the X-ray imaging system;
Storage means for storing inspection history information having the angle of the leg,
A bone density measuring apparatus comprising: output control means for reading out and outputting the examination history information corresponding to a subject to be examined at the time of examination from the storage means at the time of examination. The bone density measuring device according to claim 5,
Registration means for registering the angle of the leg,
The bone density measuring apparatus, wherein the registered angle of the leg is stored as the examination history information in the storage unit for each subject. The bone density measuring device according to claim 6,
The registration means is an input means,
A bone density measuring apparatus characterized in that an angle of the leg is input and registered by the input means. The bone density measuring device according to any one of claims 5 to 7,
The bone density measuring device according to claim 1, wherein the angle of the leg is an internal rotation angle of the leg. In the bone density measuring device according to any one of claims 5 to 8,
An apparatus for measuring bone density, comprising: an image generating means for acquiring a difference between an image photographed under a high voltage condition and an image photographed under a low voltage condition to generate a subtraction image.

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