WO2008044439A1 - Appareil pour déterminer la teneur en sel d'un os - Google Patents

Appareil pour déterminer la teneur en sel d'un os Download PDF

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Publication number
WO2008044439A1
WO2008044439A1 PCT/JP2007/068148 JP2007068148W WO2008044439A1 WO 2008044439 A1 WO2008044439 A1 WO 2008044439A1 JP 2007068148 W JP2007068148 W JP 2007068148W WO 2008044439 A1 WO2008044439 A1 WO 2008044439A1
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WO
WIPO (PCT)
Prior art keywords
ray
bone mineral
subject
mineral content
rays
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PCT/JP2007/068148
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English (en)
Japanese (ja)
Inventor
Hiromu Ohara
Yuko Shinden
Original Assignee
Konica Minolta Medical & Graphic, Inc.
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Application filed by Konica Minolta Medical & Graphic, Inc. filed Critical Konica Minolta Medical & Graphic, Inc.
Priority to JP2008538613A priority Critical patent/JPWO2008044439A1/ja
Publication of WO2008044439A1 publication Critical patent/WO2008044439A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/48—Diagnostic techniques
    • A61B6/484—Diagnostic techniques involving phase contrast X-ray imaging
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/04—Positioning of patients; Tiltable beds or the like
    • A61B6/0478—Chairs
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/48—Diagnostic techniques
    • A61B6/482—Diagnostic techniques involving multiple energy imaging
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/50—Clinical applications
    • A61B6/505—Clinical applications involving diagnosis of bone

Definitions

  • the present invention relates to a bone mineral content measuring apparatus, and more particularly, to a bone mineral content measuring apparatus that measures bone mineral content using single energy X-rays.
  • bone mineral quantification methods used to measure this bone mineral content include the dual energy X-spring absorption method (Dual X-ray Absorptiometry: DXA method) and the quantitative ultrasonic bone density measurement method (Quantitative Ultrasound: QUS method). ), Quantitative X-ray CT (Quantitative Computed Tomography: QCT), single energy X-ray absorption (SXA method), etc. are currently known.
  • the heavy energy X-ray absorption method has become the standard method for bone mineral content measurement!
  • a difference signal is obtained by performing energy subtraction between a plurality of images obtained by irradiating radiations having different energy levels.
  • Image signal and subtracting between the correction image signal averaged in the main scanning direction and / or sub-scanning direction and the difference signal to obtain a correction difference signal, and this correction difference signal.
  • a method of performing bone mineral quantitative analysis by the method for example, see Patent Document 1.
  • the subject is irradiated with a single energy X-ray and the X-ray absorption value of the subject is measured.
  • the filter thickness, collimator diameter, tube voltage and current are optimized.
  • a bone mineral content measuring device that makes X-rays monochromatic with a simple configuration has been proposed (for example, see Patent Document 3).
  • Patent Document 1 Japanese Patent Laid-Open No. 5-1111480
  • Patent Document 2 JP-A-2005-192657
  • Patent Document 3 Japanese Patent Laid-Open No. 2005-319236
  • Non-Patent Document 1 Toyofuku Inoue 7 "Bone salt quantitative measurement with phase contrast mammography (PCM) apparatus-Basic study with aluminum and water phantom" Jpn. J. Med. Phys., Vol. 26 supplement No. 3 , pp. 77—78, (2006)
  • osteoporosis increases with aging, and fractures of elderly people, particularly femoral neck fractures, are likely to be bedridden.
  • bone mineral content rapidly decreases, and fractures are more likely to occur when it is below 0.70 g / cm 2 .
  • Increasing the number of patients with osteoporosis is not only an obstacle to the lives of individual patients, but also a major problem in Japan, where the elderly population is increasing, which spurred an increase in medical expenses.
  • osteoporosis can be prevented by force by taking appropriate exercise and taking sufficient calcium from the diet. Therefore, it is important for individuals to accurately grasp their own bone mineral content at an early stage and strive to prevent osteoporosis. Therefore, today, bone mineral quantification is being examined.
  • the change in the amount of bone mineral is very small, and the measurement error of bone mineral content determination for osteoporosis prevention and early detection is required to be around 1%. Even if calcium is adequately consumed and appropriate exercise is continued, the increase in bone mineral density is considered to be about 0.5% per year, and appropriate prevention, early detection and treatment of osteoporosis are performed. In order to do this, it is preferable to regularly check the bone mineral content for a long period of at least several years and observe the progress. Therefore, bone mineral content can be easily measured for the prevention and early detection of osteoporosis. It is required to do so.
  • osteoporosis is a disease that affects a large number of elderly people. Therefore, it is preferable to measure the amount of bone mineral in such a way as to impose as little burden on the person undergoing the examination as possible.
  • the dual energy X-ray absorption method has excellent measurement accuracy but has a drawback that it takes time force S of several minutes or more for measurement. For this reason, it is not preferable as a method of screening regularly performed by elderly people.
  • information cannot be obtained as a high-resolution image simultaneously with the measurement of bone mineral content.
  • Quantitative X-ray CT examination has the disadvantage that it has a large power exposure dose that can obtain information in three dimensions, and is not suitable for examinations (especially, examinations that are performed regularly over a long period of time).
  • the quantitative ultrasonic bone density measurement method using an ultrasonic device has problems such as measurement accuracy. Not suitable.
  • the single energy X-ray absorption method can measure the amount of bone mineral by taking an image of the subject using an X-ray film, etc., and the bone mineral content can be determined most easily. It is a technique.
  • the X-rays emitted from the tungsten anode X-ray tube are multi-colored X-rays, and the normal bone scan is set to a tube voltage of 50 kVp or higher, so the measurement accuracy is extremely low! For this reason, the single energy X-ray absorption method now plays an auxiliary role for other methods! /, But this method alone can be used for medical purposes such as early detection of osteoporosis and confirmation of progress. Is unbearable! /.
  • Non-Patent Document 1 uses refraction contrast enhancement caused by X-ray refraction in order to diagnose a shadow caused by microcalcification or disease in the breast.
  • a molybdenum anode X-ray tube as a radiation source.
  • bone mineral content In order to measure accurately, it is preferable to perform quantification based on the absorption contrast image of the bone, but it is taken using a molybdenum anode X-ray tube with an emission line spectrum, which tends to cause refraction contrast enhancement.
  • an increase or decrease in X-ray dose due to refraction contrast appears near the edge of the bone. For example, when bone mineral content is measured by photographing a plurality of small bones such as fingers, there is a concern that some errors may occur in the measured value compared to bone mineral content measurement by other methods.
  • the present invention has been made to solve the above-described problems, and enables simple bone mineral quantification that can be used for a wide range of examinations with less burden even for elderly people. It is another object of the present invention to provide a bone mineral content measuring apparatus capable of realizing measurement accuracy usable for follow-up for early detection and treatment of osteoporosis.
  • the bone mineral content measuring device captures an X-ray image of a subject, and based on the obtained image data, the subject is measured.
  • a bone mineral content measuring device for measuring the bone mineral content of a specimen captures an X-ray image of a subject, and based on the obtained image data, the subject is measured.
  • An X-ray detector for recording an X-ray image corresponding to an X-ray dose irradiated from the X-ray source and a liquid substance holding member for holding a liquid substance containing the subject at the time of imaging;
  • the source is a tungsten anode X-ray tube with an intrinsic filtration of 2.5 mm thick aluminum or more,
  • the X-ray detector has a dynamic range of 3 digits or more and is arranged so that the distance from the subject is 15 cm or more! /.
  • the invention according to claim 2 is the bone mineral content measuring device according to claim 1.
  • the X-ray source has a tube voltage set to 20 kVp or more and 49 kVp or less.
  • the invention described in claim 3 is the bone mineral content measuring device described in claim 1 or claim 2!
  • the X-ray source is characterized in that the tube voltage is set to 25 kVp or more and 39 kVp or less.
  • the invention according to claim 4 is the bone mineral content measuring device according to any one of claims 1 to 3, wherein
  • the dynamic range of the X-ray detector is 7 digits or less.
  • the invention according to claim 5 is the bone mineral content measuring device according to any one of claims 1 to 4, wherein
  • the X-ray detector is arranged so as to have a distance force im or less with respect to the subject.
  • the invention according to claim 6 is the bone mineral content measuring device according to any one of claims 1 to 5, wherein
  • the dynamic range of the X-ray detector is as wide as 3 digits or more! / X-rays that greatly decrease at bones with high X-ray absorption when irradiated with low-energy X-rays are sufficient.
  • an image contrast capable of measuring the bone mineral content can be obtained, and the measurement accuracy of the bone mineral content can be improved.
  • the tube voltage exceeds 49kVp, the bremsstrahlung X-ray increases more than necessary and the measurement accuracy deteriorates.
  • the tube voltage is set to 49kVp or less, so the measurement accuracy It will not deteriorate.
  • the tube voltage is set to 25 kVp or more and 39 kVp or less, the transmitted X-ray dose necessary for measuring the bone mineral content is obtained and the bremsstrahlung X There is an effect that it is possible to appropriately prevent deterioration in measurement accuracy due to an increase in the number of lines more than necessary.
  • the apparatus can be downsized.
  • the subject since the subject is a human finger or foot, it is not necessary to take a picture in a lying position, for example, while sitting on a chair or the like on a subject table.
  • the amount of bone mineral can be measured by a simple method such as performing an examination while holding the hand. For this reason, the amount of bone mineral is low even when the burden on the subject is small, such as when the subject is an elderly person.
  • the effect of the fact that the measurement and measurement of the above can be easily and conveniently performed can be achieved. .
  • FIG. 11 Side side view showing the configuration of the main part of the bone and bone salinity measuring instrument mounting device according to the present embodiment. It is a figure. .
  • FIG. 22 Schematic diagram showing the internal / internal structure of the bone / salt salinity measuring / mounting apparatus in the present embodiment. It is. .
  • FIG. 33 Front view showing the main components of the bone / salt salinity measuring / mounting device in the present embodiment. It is a figure. .
  • FIG. 1 to FIG. 3 show a configuration example of the bone mineral content measuring apparatus 1 in the present embodiment.
  • the bone mineral content measuring device 1 is connected to a communication network (not shown; hereinafter simply referred to as “network”) such as a LAN (Local Area Network) via a switching hub (not shown), for example.
  • a communication network such as a LAN (Local Area Network)
  • LAN Local Area Network
  • Switch not shown
  • the film may be output from (not shown).
  • the configuration of the bone mineral content measuring device 1 is not limited to the one exemplified here.
  • the bone mineral content measuring device 1 outputs the measurement result (display or film output) of the bone mineral content. May also be configured.
  • a support base 3 is provided on an imaging main body 4 serving as a base so as to be movable up and down with respect to the support 2. Yes.
  • an imaging body 4 having a substantially rectangular parallelepiped shape is rotatably supported via a support shaft 5 in the CW direction and the CCW direction (see FIG. 3 (a)).
  • the bone mineral content measuring apparatus 1 is inclined when imaging is performed with the apparatus angle perpendicular to the ground during imaging. It can be used when shooting at an angle of about 45 degrees (see Fig. 3 (b)).
  • the support base 3 is provided with a drive device 6 that drives its elevation and rotation of the support shaft 5.
  • the drive device 6 includes a known drive motor (not shown) and the like, and the support base 3 and the imaging main body 4 are moved up and down according to the position of the subject H.
  • the bone mineral content measuring device 1 can perform imaging for performing bone mineral content measurement (bone mineral content determination) and general X-ray image imaging with a single device.
  • the support base 3 and the imaging main body 4 can be moved according to the position of the subject H suitable for each imaging.
  • the position of the subject H suitable for imaging is the vicinity of the chest of the subject sitting on the chair X or the chest. The position is adjusted so that it is less likely to get tired when the subject immerses his / her finger in a water tank 30 placed on the subject table 14 described later. It is possible.
  • the support base 3 and the imaging main body 4 are set in accordance with the position of the subject H so that the apparatus is in a state suitable for imaging the subject H.
  • the height and position can be adjusted.
  • the photographing main body 4 is provided with a holding member 7 along the vertical direction.
  • An X-ray source 8 that emits 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 main body unit 4.
  • An aperture 10 for adjusting the X-ray irradiation field is provided at the X-ray emission port of the X-ray source 8 so as to be freely opened and closed.
  • a tungsten anode X-ray tube is applied as the X-ray source 8.
  • a tungsten anode X-ray tube for example, UH-6RC-307EY type X-ray tube (Hitachi Medical DHF-155HII high-pressure generator) manufactured by Hitachi Medical Corporation can be used.
  • an additional filter 81 is attached to the X-ray source 8.
  • the attached calofilter 81 for example, molybdenum, rhodium, aluminum or the like can be used.
  • the thickness of the additional filter 81 can be equal to or greater than 2.5 mm of aluminum. At this time, it is preferable to narrow the X-ray energy width using a diffraction grating or the like.
  • Fig. 4 shows an X-ray spectrum obtained from an X-ray tube with a molybdenum anode and X obtained from an X-ray tube with a tungsten anode without an additional filter 81 when the applied tube voltage is 30 kVp.
  • the line spectrum W is shown.
  • the maximum X-ray intensity is 100, and the relative intensity is shown.
  • the X-ray spectrum Mo has a large effect on the human body. 17. Extremely strong X-rays with a peak near 8keV are generated.
  • the X-ray detector 11 is taken away from the subject H, The X-rays that are absorbed and attenuated by and are refracted and superimposed near the edge of the bone.
  • the X-ray spectrum W an emission line spectrum is generated in the vicinity of lOkeV. From 15keV to 30keV, the characteristic X-rays are distributed gently. However, the X-ray dose is attenuated when the X-rays are transmitted through the bone by removing the emission line spectrum near lOkeV by the additional filter 81. Can be relaxed, and the accuracy of bone mineral content measurement is improved.
  • the additional filter 81 By attaching the additional filter 81 to the X-ray tube of the tungsten anode, as shown in FIG. 5, X-rays in the low energy band V that adversely affect the human body are removed by the additional filter 81. As a result, the X-ray energy width of the X-rays emitted from the X-ray source 8 is reduced, and unnecessary portions of the multicolor X-rays emitted from the X-ray tube of the tungsten anode are removed to remove the X-rays. Can be monochromatic.
  • the X-ray source 8 is preferably a rotating anode X-ray tube!
  • X-rays are generated when an 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 rotating anode X-ray tube causes an electron beam to collide with a surface of a certain size of the anode, and the generated X-ray is emitted toward the subject H from the plane of the certain size of the anode.
  • the size of the plane viewed from this irradiation direction (subject direction) is called the focus.
  • the focus size D (11 m) is the length of one side when the focus is square, the length of the short side when the focus is rectangular or polygonal, and the diameter when the focus is circular. Point.
  • the larger the focal spot size D the more X-rays are emitted.
  • the focal spot size of the X-ray tube of the X-ray source 8 used in this embodiment is 1 ⁇ m force, preferably 500 ⁇ m force S. If it is less than 1 am, a sufficient amount of X-rays that pass through the subject H can be obtained within a few seconds. I can't. If it is longer than 500 m, the image will be blurred and the measurement accuracy will be reduced.
  • the bone mineral content measuring apparatus 1 can adjust the set value of the tube voltage of the power supply unit 9 so that the tube voltage is adjusted and applied to the X-ray source 8. It is now possible to irradiate X-rays with the desired amount of energy!
  • the bone mineral content measuring apparatus 1 can measure the bone mineral content and take a general X-ray image as described above, and measures the bone mineral content.
  • the tube voltage applied to the X-ray source 8 is 20 kVp or more and set to 49 kVp or less.
  • the more preferable setting tube voltage is 25 kVp or more and 39 kVp or less. If the tube voltage is too low, all of the irradiated X-rays are absorbed by the bone of subject H and the amount of transmitted X-rays required for measurement cannot be obtained! /. If the tube voltage is too high, the bremsstrahlung X-rays will increase more than necessary and the measurement accuracy will deteriorate.
  • the bone mineral content measuring apparatus 1 can measure the bone mineral content in a low energy band (15 keV to 4) called so-called soft X-ray with a tube voltage of 50 kVp or less. OkeV) X-ray images can be taken.
  • the tube voltage applied to the X-ray source 8 was set to 50 kVp or higher. Had gone. By setting the tube voltage as high as this, it is possible to obtain an image contrast that can withstand diagnosis and the like even when the dynamic range force is about three orders of magnitude.
  • the tube voltage applied to the X-ray source 8 is set lower than 50 kVp, the force that can provide an image contrast that can withstand diagnosis etc. for soft tissues such as skin S, the magnitude of X-ray absorption Sufficient contrast cannot be obtained at the bone.
  • a digital X-ray detector having a wide dynamic range is used as the X-ray detector 11 as will be described later, so that X-rays that greatly decrease in the bone can be sufficiently diagnosed.
  • a tolerable contrast can be obtained and bone mineral content can be measured.
  • the tube voltage applied to the X-ray source 8 is set to 50 kVp or more and 150 kVp or less.
  • general X-ray imaging both low-energy imaging and high-energy imaging are performed.
  • subtraction processing energy subtraction processing
  • a tube voltage of 60 kVp is applied in the case of shooting in the low energy band, and in the case of shooting in the high-engineering energy band.
  • a tube voltage of 120 kVp is applied to the.
  • tube voltage at the time of bone mineral content measurement and the tube voltage at the time of general X-ray imaging are not limited to the ranges exemplified here.
  • One end of a detector holding unit 12 that holds an X-ray detector 11 that detects X-rays that have passed through the subject H is attached to the lower part of the holding member 7.
  • the X-ray detector 11 can be pulled out from the detector holding portion 12 in the horizontal direction (FIG. 3 (a)). It is preferable that the X-ray detector 11 can be pulled out in both the left and right directions.
  • the X-ray detector 11 is fixed in the detector holding portion 12 by a fixing means (not shown) so as not to drop during oblique imaging.
  • a digital X-ray detector such as CR (Computed Radiography) force set or FPD (Flat panel X-ray detector) containing a stimulable phosphor sheet is applied.
  • the power to do S is applied.
  • a CR force set for example, a REGIUS force set for the REGIUS Vstage Model 190 can be used.
  • the X-ray detector 11 is not limited to CR or FPD as long as it is a digital X-ray detector.
  • Silver halide photographic light-sensitive materials have been widely used for conventional X-ray imaging.
  • the amount of X-ray transmitted through the subject is measured.
  • the dynamic range force is about an order of magnitude, and accurate measurement is impossible.
  • image data can be obtained directly as a digital image signal, which can be processed accurately and quickly.
  • the X-ray detector 11 has a dynamic range of three digits or more.
  • the density range of the image detected by the bone mineral content measuring apparatus 1 in this embodiment is 3 Corresponds to X-ray absorption coefficient of more than digits.
  • the X-rays irradiated to the subject H are attenuated (decreased) by several tenths by passing through the bone.
  • the X-ray intensity distribution on the surface of the two-dimensional X-ray detector 11 usually has a difference (variation) of about twice the maximum value and the minimum value of the X-ray intensity. Therefore, in order to accurately measure the bone mineral content, it is necessary to perform X-ray intensity correction (shading correction described later) on the X-ray detector 11 surface.
  • the dynamic range of the X-ray detector 11 needs to be at least three digits or more in order to accurately measure bone mineral density. Since the dynamic range is 3 digits or more, it is possible to achieve higher sensitivity and higher resolution than when shooting with X-ray film, etc., and the tube voltage applied to the X-ray source 8 is low! /, Even when taking images in the low energy band, it is possible to detect images with good contrast.
  • the dynamic range is not particularly limited as long as it is 3 digits or more, and the dynamic range is as wide as possible in consideration of measurement errors. However, if the dynamic range exceeds 7 digits, it takes time to process the image data and the equipment becomes expensive, so the dynamic range is preferably 7 digits or less! /.
  • the relative position of the X-ray source 8 and the detector holding unit 12 is fixed, and the distance is R.
  • the distance from X-ray source 8 to subject H is rl
  • the distance between subject H and the X-ray detector is r2.
  • both the distance from the X-ray source 8 to the subject and the distance from the subject to the X-ray detector 11 may be appropriately variable.
  • the distance from the subject H to the X-ray detector 11 is 15 cm or more.
  • the distance force m to the subject H-force X-ray detector 11 when the distance force m to the subject H-force X-ray detector 11 is exceeded, the apparatus becomes very large.
  • the X-ray dose to be detected by the X-ray detector 11 is greatly reduced by the distance square law, if the distance is too far, the image is not sharp. For this reason, the distance from the subject H to the X-ray detector 11 is preferably lm or less.
  • An X-ray dose detector 13 for detecting the irradiated X-ray dose is provided below the holding member 7 and on the lower surface of the detector holder 12.
  • a flat object table 14 is provided so that one end thereof is attached to the holding member 7.
  • the subject table 14 is provided with a motor or the like that changes the position relative to the holding member 7 in order to enable imaging magnification adjustment (position adjustment in the height direction) during phase contrast imaging in general X-ray imaging. Connected to device 15.
  • a water tank 30 for inserting the finger of the subject who is the subject H at the time of radiographing can be attached to and detached from the X-ray irradiation region irradiated from the X-ray source 8 on the subject table 14. It is placed.
  • the water tank 30 is a liquid material holding member that holds the liquid material 31 containing the subject H at the time of imaging, and the subject H is placed in the water tank 30 inside the water tank 30. At this time, the liquid material 31 is held in such an amount that the entire specimen H can be sufficiently immersed.
  • the subject H is submerged in the liquid material 31 having a certain depth, and X-ray imaging is performed with the subject H sufficiently immersed.
  • the depth (amount) of the liquid material 31 held in the water tank 30 varies depending on the subject H. For example, about 3 cm to 10 cm for fingers and about 5 cm to 15 cm for feet.
  • liquid substance 31 water is most convenient, inexpensive and safe because it is preferable. You may use the thing which added the fragrance
  • a liquid 31 that is closer to human flesh and body fluid than water.
  • a hyaluronic acid solution, a gelatin solution, a glycerin solution, a mannose solution, a rice juice, a starch solution, etc. alone or in a solution with water can be used.
  • the liquid material 31 may be held in the water tank 30 after being placed in a plastic bag or the like so that the subject H does not directly touch the liquid material 31.
  • the subject table 14 place the finger, which is the subject H, on the subject table 14 and then place the liquid 31 in a plastic bag on the finger during imaging, for example, using a compression plate. Then press liquid 31 from above. As a result, the thickness of the finger and the liquid material 31 can be made constant.
  • the subject table 14 that does not require the water tank 30 functions as a liquid material holding member that holds the liquid material 31 placed in a plastic bag or the like.
  • liquid 31 or the liquid 31 in a bag or the like may be heated to about body temperature.
  • a fixing tool (not shown) for fixing the subject's fingers can be attached to and removed from the subject table 14 by itself.
  • the bone mineral content measuring apparatus 1 is capable of taking a general X-ray image in addition to measuring the bone mineral content (bone mineral content) as described above.
  • the bone mineral content measuring apparatus 1 When taking general X-ray images, remove the aquarium 30 from the subject table 14, place a finger on the subject table 14 as the subject H, and fix the finger with a fixture. And then shoot.
  • the subject table 14 may be provided with a sensor or the like that detects the orientation of the fingers or the left and right.
  • An example of the bone mineral content measuring apparatus 1 in the present embodiment is as follows.
  • the entire apparatus height HI force S2200mm, the distance H2 between the X-ray tube 8 and the subject table 14 is manually in the range of 430mm to 650mm.
  • the distance H3 from the subject table 14 to the X-ray detector 11 can be manually adjusted within the range of 490 mm to 750 mm.
  • the apparatus width W is 780 mm and the apparatus depth Dl is 1160 mm
  • the limit of the distance A shown in FIG. 1 is preferably about 440 mm
  • the limit of the distance B is preferably about 470 mm.
  • the height of the subject table 14 (distance from the subject table 14 to the ground) H4 is preferably 900 mm or less (see FIG. 2).
  • X-rays are irradiated on the end of the imaging apparatus main body 4 above the subject table 14 so that X-rays emitted from the X-ray source 8 do not reach the subject.
  • a shielding face guard 21 is provided extending substantially in the vertical direction.
  • the subject should be at the shooting position on the lower surface of the subject table 14 without hitting the leg.
  • the protector 25 is provided so as to extend substantially in the vertical direction. As a result, the subject can reach the imaging position without hitting his / her leg on the detector holding unit 12.
  • fixing tool the face guard 21 and the protector 25 are not essential components, and the fixing tool, the compression plate 21 and the protector 25 may not be used.
  • the imaging main unit 4 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (all not shown).
  • a control device 22 is provided.
  • An X-ray dose detection unit 13, a power supply unit 9, a drive device 6, and a position adjustment device 15 are connected to the control device 22 via a bus 23.
  • the control device 22 includes a keyboard touch panel (not shown) for inputting photographing conditions and the like, an input device 24a having a position adjusting switch for adjusting the position of the object table 14, and the CRT.
  • An operation device 24 having a display device 24b such as a display or a liquid crystal display is connected.
  • the ROM of the control device 22 stores a control program and various processing programs for controlling each part of the bone mineral content measuring device 1.
  • the CPU cooperates with the control program and the various processing programs.
  • the bone mineral content measuring device 1 controls the operation of each part in an integrated manner, performs X-ray imaging, and generates X-ray image data.
  • the CPU controls the driving device 6 on the basis of the imaging conditions of the subject, measurement of bone mineral content or general X-ray imaging! /, The type of imaging, and the like. Raise and lower 4 to a height that matches the height of the subject, and rotate support shaft 5 to adjust the X-ray irradiation angle. Then, the position adjustment device 15 adjusts the position of the subject table 14 and adjusts the magnification of phase contrast imaging in the case of general X-ray imaging. Thereafter, the imaging unit 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 X-rays. When the X-ray dose input from 13 reaches the preset X-ray dose, the X-ray irradiation from the X-ray source 8 is stopped by controlling the power supply unit 9.
  • the ROM of the control device 22 includes various programs related to image processing and bone mineral quantification, such as an image processing program and bone mineral quantification program, as well as these processes. Stores various data used when executing physical programs.
  • the CPU of the control device 22 cooperates with these control programs and various processing programs to measure the bone mineral content based on the image processing of the acquired image data and the data subjected to the image processing. I do.
  • control device 22 performs the following processing.
  • the control device 22 performs X-rays using an aluminum step in order to correct the device characteristics when the bone mineral content measuring device 1 is shipped from the factory or when it is installed at the installation location. Take a picture and based on the obtained image data, find the shading correction value for the deviation of the X-ray dose on the 14th subject table. Then, shading correction is performed on the image data based on the obtained correction value.
  • X-ray imaging is performed using a bone mineral quantification phantom containing calcium carbonate.
  • the control device 22 transmits the bone mineral quantitative phantom from the X-ray amount detected by the X-ray detector 11 and transmitted through the bone mineral quantitative phantom and the calcium carbonate content in the bone mineral quantitative phantom. Determine the relationship between X-ray dose and calcium carbonate content.
  • the control device 22 calculates the relationship for each tube voltage of the X-ray source 8. Store in a storage unit (not shown) such as ROM. Then, when an image is taken to measure the bone mineral content of the subject H, it is stored in association with the tube voltage of the X spring source 8 at the time of imaging! /, X dose and carbonate content The bone mineral content is quantified based on the relationship. Note that the relationship between the X-ray dose stored in the storage unit of the control device 22 and the calcium carbonate content is not limited to this if the bone mineral content can be quantified. And the calcium carbonate content, or the X-ray dose detected by the X-ray detector 11 and the calcium equivalent amount.
  • control device 22 when performing general X-ray image capturing, the control device 22 performs gradation processing and density adjustment for adjusting the image contrast to the image data of the X-ray image acquired by the X-ray detector 11. Image processing such as adjustment processing and frequency processing for adjusting sharpness is performed. As a result, it is possible to perform image processing suitable for conditions such as an imaging region.
  • the aluminum step was used to determine the shearing correction value for the X-ray irradiation bias on the 14th surface of the subject table, and the X-ray image was taken using the bone mineral quantification phantom. Find the relationship between absorbed and attenuated X-ray dose and calcium carbonate content.
  • the height of the subject table 14 is adjusted to the position of the subject H of the subject, and the X-ray detector 11 and the subject H are separated by a distance of 15 cm or more and lm or less. Adjust as follows. Further, a water tank 30 holding an appropriate amount of liquid substance 31 is placed at a predetermined position on the subject table 14, and the subject H is immersed in the water tank 30. For example, when the subject H is a finger, the finger is sufficiently immersed in the liquid 31 in the water tank 30. Then, a predetermined amount of X-rays are irradiated from the X-ray source 8 with the fingers immersed in the liquid material 31 of the water tank 30, and X-ray images are taken.
  • the X-ray dose detected by the X-ray detector 11 is sent to the control device 22 as image data.
  • the control device 22 first determines the bone mineral content measurement target in the image data.
  • the bone mineral content is determined based on the relationship between the X-ray dose obtained and the calcium carbonate content.
  • X-ray images are shot by irradiating soft X-rays with low energy, so in the case of an original image that is not processed, the entire image is captured. It becomes ugly and the finger image cannot be clearly identified.
  • a quantitative image obtained by performing processing based on the correction coefficient the finger image can be clearly identified, and the bone mineral content is accurately measured based on this quantitative image. It becomes possible.
  • the control device 22 executes the following processing.
  • X-ray imaging using aluminum step-edge A1 detects X-ray dose that passes through aluminum step wedge A1 with different thickness and X-ray dose that passes through acrylic Ac. Obtain the attenuation coefficient of aluminum.
  • ⁇ is a liquid such as water as described above.
  • ⁇ is the bone of the finger that is the subject's heel.
  • L can be made constant by immersing your finger in the water tank 30 containing the liquid material 31 such as water and adjusting the amount of the liquid material 31.
  • the thickness of the object is set to “L”.
  • the X-ray dose incident on the object is “I”, and the X-ray dose attenuated by the object is “I”.
  • Equation (5) is obtained from Equation (4).
  • the energy (Eeff) corresponding to Lu is obtained based on the absorption coefficient database.
  • Equation (8) is obtained from Equation (6) and Equation (7).
  • the control device 22 then calculates the calculation result X and the actual aluminum step edge.
  • the correction coefficient in the bone mineral content measuring device 1 is obtained.
  • control device 22 performs quantitative measurement of aluminum using this correction coefficient.
  • the image density correlates with the X-ray dose detected by the X-ray detector 11
  • the X-ray dose and the X-ray attenuation rate are measured.
  • the theoretical thickness X of the aluminum step edge A1 as described above.
  • A1 can be calculated. Then, by correcting using the correction coefficient, the thickness X of the aluminum can be quantified.
  • the bone mineral content measuring device 1 in the present embodiment the bone mineral content is simply and accurately measured using an apparatus that can be used for general X-ray imaging. That power S.
  • bone mineral content can be measured at the time of regular medical examinations, etc., and measurement can be repeated over time. For this reason, prevention and early detection of osteoporosis that often occurs in the elderly can be performed with as little burden as possible on the elderly.
  • tungsten anode X-ray tube is used as the X-ray source 8 with a low tube voltage setting, X-rays with excellent monochromaticity can be obtained, and accurate bone mineral content can be measured. Can do.
  • the tungsten anode X-ray tube is extremely strong in the specified energy band like the molybdenum anode X-ray tube! /, And there is no characteristic X-ray that generates the emission line spectrum! /, So it is gentle over a certain energy band. Distributing characteristics X-rays can be used, and the attenuation of X-ray dose when X-rays pass through the bone is mitigated, and the accuracy of bone mineral content measurement is improved.
  • the tube voltage of the X-ray source 8 is 20 kVp or more, 49 kVp or less, more preferably 25 kVp or more, Therefore, the transmission X-ray dose necessary for bone mineral content measurement can be obtained, and the bremsstrahlung X-ray does not increase more than necessary, so the measurement accuracy is not deteriorated. .
  • the scattered X-rays can be reduced without reducing the primary X-ray dose due to the so-called Gradel effect. Can capture the transmitted X-ray dose from X-rays with better monochromaticity.
  • the distance force between the X-ray detector 11 and the subject H is less than Sim, the measurement accuracy of the bone mineral amount is increased so that the X-ray dose to be detected by the X-ray detector 11 does not greatly decrease. .
  • the size of the apparatus can be reduced.
  • the dynamic range of the X-ray detector 11 is as wide as 3 digits or more, X-rays that greatly decrease in the bone can be measured sufficiently, and the measurement accuracy of bone mineral content can be improved.
  • the dynamic range is 7 digits or less, the time spent on image data processing is short, and the device cost can be kept low.
  • subject H is a human finger or the like
  • the subject sat in chair X and dipped his hand into aquarium 30 placed on subject table 14 in front of the apparatus.
  • the bone mineral content can be measured by a simple method of photographing in a state.
  • the force S and the bone mineral content measuring device 1 configured so that the bone mineral content measuring device 1 can also serve as a general X-ray imaging apparatus are: It may be a dedicated machine for measuring bone mineral content.
  • the force subject H is not limited to the force H as an example of the human hand as the subject H, and the bone mineral content is measured using the foot or other body part as the subject H. May be.

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Abstract

L'invention concerne un appareil pour déterminer la teneur en sel d'un os qui est largement applicable à des examens médicaux en raison du fait qu'il permet une détermination pratique de la teneur de masse osseuse, tout en imposant peu de charge même sur des sujets âgés, et qui peut établir une telle précision élevée qu'il peut être utilisé dans la détection précoce de l'ostéoporose et le suivi du traitement de celle-ci.
PCT/JP2007/068148 2006-10-06 2007-09-19 Appareil pour déterminer la teneur en sel d'un os WO2008044439A1 (fr)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012517313A (ja) * 2009-02-12 2012-08-02 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ インタフェース装置、イメージングシステム及び辺縁部イメージング方法
WO2013005848A1 (fr) * 2011-07-07 2013-01-10 株式会社東芝 Détecteur d'image de compteur de photons, appareil de diagnostic par rayons x et appareil de tomodensitométrie
JP2014054301A (ja) * 2012-09-11 2014-03-27 Hitachi Aloka Medical Ltd 医療用ｘ線測定装置
JP2014079406A (ja) * 2012-10-17 2014-05-08 Hitachi Aloka Medical Ltd 骨密度測定用アダプタ
US8989346B2 (en) 2011-12-28 2015-03-24 Fujifilm Corporation Bone mineral density analysis method, bone mineral density analysis apparatus, and recording medium
US10101469B2 (en) 2011-01-25 2018-10-16 Hamamatsu Photonics K.K. Radiation image acquisition device
JP2018161417A (ja) * 2017-03-27 2018-10-18 株式会社日立製作所 骨密度測定装置
US10234406B2 (en) 2012-07-20 2019-03-19 Hamamatsu Photonics K.K. Radiation image acquisition system
US10859715B2 (en) 2015-09-30 2020-12-08 Hamamatsu Photonics K.K. Radiation image acquisition system and radiation image acquisition method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06179A (ja) * 1992-06-22 1994-01-11 Aloka Co Ltd 骨塩量測定方法及び装置
JPH08503637A (ja) * 1992-11-25 1996-04-23 アーノルド，ベン・エイ カルシウム密度を定量化する装置および方法
JP2003520115A (ja) * 2000-01-24 2003-07-02 マメア イメイジング アクチボラゲット Ｘ線画像生成装置に関する方法および機構

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06179A (ja) * 1992-06-22 1994-01-11 Aloka Co Ltd 骨塩量測定方法及び装置
JPH08503637A (ja) * 1992-11-25 1996-04-23 アーノルド，ベン・エイ カルシウム密度を定量化する装置および方法
JP2003520115A (ja) * 2000-01-24 2003-07-02 マメア イメイジング アクチボラゲット Ｘ線画像生成装置に関する方法および機構

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012517313A (ja) * 2009-02-12 2012-08-02 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ インタフェース装置、イメージングシステム及び辺縁部イメージング方法
US10101469B2 (en) 2011-01-25 2018-10-16 Hamamatsu Photonics K.K. Radiation image acquisition device
US10746884B2 (en) 2011-01-25 2020-08-18 Hamamatsu Photonics K.K. Radiation image acquisition device
WO2013005848A1 (fr) * 2011-07-07 2013-01-10 株式会社東芝 Détecteur d'image de compteur de photons, appareil de diagnostic par rayons x et appareil de tomodensitométrie
JP2013019698A (ja) * 2011-07-07 2013-01-31 Toshiba Corp 光子計数型画像検出器、ｘ線診断装置、及びｘ線コンピュータ断層装置
US9213108B2 (en) 2011-07-07 2015-12-15 Kabushiki Kaisha Toshiba Photon counting type image detector, X-ray diagnosis apparatus and X-ray computed tomography apparatus
US8989346B2 (en) 2011-12-28 2015-03-24 Fujifilm Corporation Bone mineral density analysis method, bone mineral density analysis apparatus, and recording medium
US10234406B2 (en) 2012-07-20 2019-03-19 Hamamatsu Photonics K.K. Radiation image acquisition system
JP2014054301A (ja) * 2012-09-11 2014-03-27 Hitachi Aloka Medical Ltd 医療用ｘ線測定装置
JP2014079406A (ja) * 2012-10-17 2014-05-08 Hitachi Aloka Medical Ltd 骨密度測定用アダプタ
US10859715B2 (en) 2015-09-30 2020-12-08 Hamamatsu Photonics K.K. Radiation image acquisition system and radiation image acquisition method
US11237278B2 (en) 2015-09-30 2022-02-01 Hamamatsu Photonics K.K. Radiation image acquisition system and radiation image acquisition method
JP2018161417A (ja) * 2017-03-27 2018-10-18 株式会社日立製作所 骨密度測定装置

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