JPH03272753A - Method and device for measuring bone - Google Patents

Abstract

PURPOSE:To enable the measurement of bone in a wide range of lightness by regulating the quantity of light to be irradiated on a X-ray film on the basis of the judgment result whether or not the transmitted light quantity of a reference substance corresponding to the object part of measurement satisfies a prescribed resolving power. CONSTITUTION:In the judgment of bone measurement, the transmitted light quantity on the image in an aluminum stage of a X-ray film by means of the light quantity determined in accordance with a subject is obtained, and the range effectively measured as the aluminum stage is obtained, and the transmitting light quantity on the upper aluminum stage is made I1, that on the lower stage I2, the maximum value of the transmitted light quantity in the object part of measurement S1, and the minimum value thereof S2. And, a first measurement is made, and when both of the expressions S1<=I1, S2>=I2 are satisfied, a second judgment is carried out to obtain the transmitted light quantity I'1 near to and larger than the transmitted light quantity S1 and the transmitted light quantity I'2 near to and smaller than that of S2, and then the values corresponding to the thicknesses for respective stages in the range I'1 to I'2 after the A/D conversion are obtained, and the minimum of these values is made I. If the minimum value I satisfies the conditions of resolving power, the measurement of bone is carried out. Thus, bone measurement on a X-ray film in a wide range of lightness can be enabled.

Description

[Detailed description of the invention]

[Industrial Application Separation] The present invention relates to a bone measurement method and a bone measurement device. More specifically, the present invention provides an improved method and apparatus for measuring bone shape, etc., using an image on an X-ray photographic film of a bone to be examined. [Prior art] Performs various bone measurements, such as checking the developmental state of human bones and the degree of aging, and checking the range of types of bone lesions such as osteoporosis and osteomalacia, the degree of progression of their symptoms, and the effectiveness of treatment. It may be done. As a method of bone measurement, Xs! The MD method uses an X-ray photographic film obtained by irradiation to measure the density of the image on the film using a microdensitometer to measure bone ("Bone Metabolism" Vol. 13, 18).
pp. 7-195 (1980), “Bone Metabolism” Vol. 14,
91-104 (1981), etc.), and photon absorption geometry, in which bone measurement is performed by irradiating gamma rays onto the bone to be examined. The MD method is easy to adopt in that it uses an X-ray photographic film that can be easily obtained using an X-ray image transport device that is widely used as a device for diagnosing fractures, etc., and is gradually becoming more widespread. . Furthermore, photon absorption geometry
As for the device that generates gamma rays, xI!
It cannot be said that they are more widely used than photographic devices. [Problems to be Solved by the Invention] Bone measurement using the conventional MD method has involved manual work in large part, as described below. That is, using an X-ray photographic film obtained by irradiating the bone to be examined with X-rays, first manually determine the reference points necessary for bone measurement using the MD method for the image of the bone on the film, and then A site (for example, a site on a transverse line at the midpoint of the long axis of the first metacarpal bone) is selected for bone measurement in detail according to a predetermined method using points. Next, while scanning the selected area with a microdensitometer, the intensity of the transmitted light obtained by irradiating the area with light is measured, and the intensity or absorbance of the transmitted light corresponding to the scanned area is measured. Have the students draw the line diagram on the designated chart paper. Furthermore, a microdensitometer is scanned over the vertical line of the film image of an aluminum step-like reference material (hereinafter referred to as aluminum step) that has been X-rayed together with the bone to be examined, and the intensity of the transmitted light obtained or Have students also write the absorbance diagram on chart paper. The thus obtained microcosms of the absorbance of the test bone and the absorbance of the aluminum stairs on the chart paper are input into a computer using a digitizer, and the absorbance of the test bone at each point is converted into the number of steps of the aluminum stairs. Using the image thus converted, various indices representing the bone morphology at the target site are calculated within the computer, and the calculation results are output. Also, regarding the previous needle measurement using the MD method, XI!
Due to fluctuations in imaging conditions and film processing conditions, the degree of shading of the image of the bone to be examined on the resulting X-ray photographic film tends to change greatly, and if the X-ray photographic film is extremely dark or bright, measurements may be difficult. There was a problem in that it was impossible to measure, or even if it could be measured, the error would be very large. [Means for Solving the Problems] As a result of intensive research by the present inventors to solve the problems in the prior art, XI! When reading an image of a bone to be examined on a photographic film by irradiating it with light and detecting the transmitted light, a means is used to adjust the amount of light generated by the light generating means according to the condition of the X-ray photographic film. We have found that this is effective and have arrived at the present invention. That is, the present invention involves, first of all, using the amount of transmitted light obtained by irradiating light onto an X-ray photographic film of a test bone carried together with a reference material of varying thickness. In the measurement method, a region of the standard material whose amount of transmitted light satisfies a predetermined condition is determined, and whether the range of the amount of transmitted light of the part to be measured falls within the range of the amount of transmitted light of the standard material in the region. A first determination is made as to whether the amount of light transmitted through the measurement target portion and the amount of transmitted light corresponding to the standard substance satisfy a predetermined resolution. The present invention includes a bone measurement method characterized by adjusting the amount of light irradiated onto the XIi photographic film. The present invention also includes a bone measurement method in which, after performing the second determination, a third determination is made as to whether or not the γ value of the measurement target portion is greater than or equal to a predetermined value. In addition, the present invention includes such a bone measurement method in which the light irradiation time is adjusted as the adjustment of the amount of irradiation light in the light generating means. Further, in the present invention, when increasing the amount of irradiation light, the amount of transmitted light I for the standard material is determined, which is larger than the maximum amount of transmitted light for the measurement target portion and close to the maximum amount of transmitted light, and the amount of transmitted light 1 is set to a predetermined value l. This includes a bone measurement method in which the amount of irradiation light is adjusted so as not to exceed wax and be close to the predetermined value 111ax. In addition, when lowering the amount of irradiation light, there is a bone measurement method that calculates the area of the part to be measured that exceeds a predetermined value of 1 wax, estimates the appropriate amount of irradiation light from the size of this area, and adjusts the amount of irradiation light. included. Furthermore, the present invention uses the amount of transmitted light obtained by irradiating light onto an X-ray photographic film obtained by irradiating xm onto a test bone together with a standard material whose thickness is varied in this bone measurement method. a reading means for reading the image in the film; an image storage means for storing the read image of the bone to be examined; and a calculation for pre-needle measurement regarding the stored image of the bone to be examined. A pre-needle measurement device comprising a calculation means for calculating the pre-needle measurement result obtained by the calculation, and a pre-needle measurement output means for outputting the pre-needle measurement result obtained by the calculation, wherein the reading means irradiates the X-ray photographic film. A light generating means for generating light, a detecting means for detecting the amount of transmitted light, a region searching means for finding a region of the standard material where the amount of transmitted light satisfies a predetermined condition, and the standard material in the region. The first step is to determine whether the range of the amount of transmitted light for the part to be measured is within the range of the amount of transmitted light for the part to be measured.
a second puncturing means for determining whether the transmitted light acid of the standard quality, which corresponds to the amount of transmitted light of the measurement target portion, satisfies a predetermined resolution and is apricot; Judgment 1
Based on the determination result of stage km (4) to the light generation means, the 7th expression to adjust the emitted light (E light rut) to the light purification adjustment means (characterized by ε). This invention includes a bone tone sub-device, and the invention includes a means for determining whether the gamma value of the measurement target part is a predetermined value. -Includes bone probing equipment. Furthermore, in this invention, when the generation tip is given as I7, for the measurement screen 4 area, the maximum transmitted light of (=)
, 1-stage to calculate the transmitted light acid I of a certain part of the standard material close to the maximum transmitted light ray, and the transmitted light amount 1 is a predetermined rectification imay
, and further comprising means for adjusting the generated light beam so that the generated light beam does not exceed 3'' or approaches the predetermined value 1 wax,
When increasing the maximum E light, a predetermined value 1I of the measurement target part
The means for determining the area exceeding max@ includes a bone measuring device that is equipped with means for estimating the appropriate amount of irradiation light from the size of this area and adjusting the amount of irradiation light. The invention also includes an image displaying means t (σ for displaying the read image as an image) for the bone to be examined;
It has a manual means for inputting the necessary reference points on both edges of the bone to be examined, and a means for storing the position of the input reference points, and roughly adjusts the light intensity. to the film.

[If re-measurement is required, run the film automatically] After adjusting σ), dynamically read the image of (-) on the standard material and the part to be measured, and use the memorized reference points. Based on (points (
'・Provides a means for inputting information and includes a review of the previous needle measurement equipment. The present invention will now be described in more detail. The image of the bone to be examined in the X-ray photograph taken in accordance with the present invention is based on the degree of blackening and the shape of the film 1 of the bone to be examined. For reference materials of varying thickness, an aluminum step is usually used, but a slab-shaped aluminum member or the like may also be used. As for the test subject t1, it is necessary to have a certain level of clear shading (anything that can obtain a 7K radiograph is sufficient, but usually the soft tissue area is thin (it is desirable to have an area that is averaged).More specifics Examples include bone grafting of the foal bone, the hypochondriac, the first ulna, the canine IIa, the tibia, and the fibula, among which the second metacarpal is the most suitable for practical use. Examples of this include bones, vertebrae, bone attachment parts, etc. Among them, the calcaneus is practical and suitable. An example is shown in Figure 1. 1rj1 is a dry plate for X-ray photographic film, 11 is a aluminum staircase, 12.13 are on the right hand, and a hand on the other hand. 14 is the first metacarpal bone. Fig. 2 is a schematic diagram of an example of a dynamic reading means for such an X-ray photographic film. (20 is an X-ray photographic film. , 21 shows the image of the bones of the hand, 22 is a band-shaped light source, 23 is a contact image sensor, and 24 is for film running.
- It shows ra. The determination in step 43 of the bone measurement method of the present invention is made by searching an X-ray photographic film for a region in which the amount of transmitted light satisfies a predetermined condition for the a3-(-1 standard material, The range of the amount of transmitted light for the part to be measured is determined, and the first determination is made as to whether or not there is a person within the range of the amount of transmitted light for the part to be measured. There is a method in which a second determination is made as to whether the amount of transmitted light of the corresponding standard substance satisfies a predetermined resolution, and the amount of irradiation light is adjusted based on the determined result.Such a determination is made. As an example of how to adjust the amount of light, the following hγ system can be cited.In other words, by using the light end determined in advance according to the gender and age of the test subject, as shown in Fig. 5, Determine the transmitted light acid of () for the image of the aluminum staircase on the X-ray photographic film that has been run to a predetermined position. Find the area being measured, that is, the area that can be resolved into steps.To effectively measure the aluminum staircase, for example, the transmitted photoacid must be converted to A/D.
When converted by an A/D converter, the A/D converted value of the amount of transmitted light corresponding to the thickness of one step of aluminum stairs is required to be 2 digits or more due to the A/D bit error. Of course, it goes without saying that the amount of transmitted light must not be saturated. Searching for the area of this aluminum staircase,
The amount of transmitted light 1+ for the upper aluminum staircase in that area,
Let I2 be the amount of transmitted light for the aluminum stairs at the lower limit. Next, the maximum value of the amount of transmitted light for the measurement target part of the bone to be examined is set to S+, and the minimum value is set to 82. First, as a first determination, it is determined whether S1≦11, and if this condition is not satisfied, the amount of irradiated light is too large and needs to be reduced. If this condition is met, it is determined whether S2≧I2, and if this condition is not met, the amount of irradiated light is too small and needs to be increased. However, in the case of S+>1+ and 82<I2, no matter how much the light amount is changed, measurement cannot be performed, so it is determined that measurement is impossible. In this case, it is preferable to display a message to this effect and to eject the film. A second determination is made when both conditions S1≦I+ and Sz≧12 are satisfied. That is, the amount of transmitted light of an aluminum staircase that is close to the amount of transmitted light of Sl, preferably the closest <Sz, is 1+', and the amount of transmitted light of an aluminum staircase that is close to the amount of transmitted light of 82, preferably the closest and smaller than Sl, is 12'.
seek. A/D converted values corresponding to the thickness of each step of the aluminum staircase in the region I+' to 12' are obtained, and the minimum value thereof is set as ΔI. For example, the thickness of one step of aluminum stairs is 1 MII, and the measurement accuracy is 0.21.
If a resolution of 11III or less is required, 5 digits (d
digit) or more, preferably 7 digits or more. For example, if 7 digits are required, it is determined whether △■≧7. If this condition is met, it is determined that the amount of irradiation light is suitable for X-ray film, and the subsequent operations necessary for pre-needle measurement are performed. If this condition is not met, the amount of transmitted light is too small and it is necessary to increase it. Next, we will discuss how to increase or decrease the amount of irradiated light. First, if it is determined that the amount of irradiated light is insufficient, the amount of transmitted light 11' is adjusted to be as close as possible to the predetermined level lwax without exceeding it, and remeasurement is performed. At this time I w
ax is 95 to 9 of the saturation level of the sensor or AD converter
It is preferable to set it to about 8%. On the other hand, if the amount of light resistance is too high, first set the predetermined level l.
The length of the measurement part exceeding laX, that is, the number of dots is counted by a line sensor or the like. For example, in the case of anterior needle measurement for the th metacarpal, this count number and (
There is a relationship between the amount of irradiated light and the appropriate irradiation device as shown in Table 1 below. Table 1 Using this relationship, the appropriate amount of irradiation light is estimated from the above count number. Here, if the number of dots exceeding l wax is O, it corresponds to an aluminum step that is one step thicker than 11, that is, a large amount of transmitted light! I n is equivalent to an aluminum step one thinner than 11+, that is, a smaller amount of transmitted light 112. Transmitted light 1 corresponding to an aluminum step two times thinner than 11
From i 13, I+t = 1 + -2,5(II2
+T13), and this amount of transmitted light I n is l
The amount of irradiation light is changed so as not to exceed Imax, but to be close to it, preferably to be closest to it. Even after resetting the irradiation light intensity, if the set value is the same as the previous time, the measurement is considered impossible and the measurement time is not wasted. In this case, it is preferable to display a message to that effect and automatically discharge the film. Furthermore, in the present invention, the third determination may be made using the γ value as necessary. That is, as shown in the following equation, the change in the γ value γ・−01) representing the OD (absorbance) change with respect to the change in relative exposure amount @/the curved edge of relative exposure amount to I+′・I7′ area ℃ each slide, f2',",,-,L
Only when this minimum fraction exceeds the predetermined value l&i')'o, it is possible to accurately measure -ζ゛C in combination with the determination of the resolution described above.
γG, L' is preferably in the range of 1 to 4.
See how to adjust C, etc. 7'l. For example, if λ is used as a means of generating irradiation light, band-shaped σ) L, ID (light e
The transmitted light separation detection means is closed using a CC[) (charge couple).
In the case of using Twinsen 4j~ consisting of dclevice), the irradiation time can be adjusted by controlling the small reactivity pulse point phantom number at l-E Di, :' by the pulse generator and '. - Zuru (X k is -" is possible. Naa5 present invention (, 2 Uu"'C1 example ki: L,,
E [-) Ya ('', C [,,) 'a When using a reading means, 1.,,,,, [E D or CC
1) Changes in characteristics such as sensitivity and illuminance over time (1.1)
/ To eliminate the honor of the 8th '4j It is practical to adjust the irradiation light by changing the irradiation time without changing the intensity. (2) For example, it is practical to store the table 72 in Table 2 in the T-stage (, for example, to adjust the setting to correspond to the irradiation time) for practical purposes 1 - efficiency. Table 2, Figure 3 shows the middle point of the long axis of the first metacarpal bone, in order to give a concrete example of the contents of the explanation for the front needle measurement of the present invention. transverse line hr
This is a pattern showing the equivalent thickness of an aluminum staircase with the amount of transmitted light. It's the shaded area (the area shown is where the distribution of bone density is expressed. d+ and d2 each indicate the mother cortex width, and d is the mother pulp). The width is 7J<, GSm + nl, t beak 40. It corresponds to the small value of the valley 42 between beak 41, and is an index of the density of (bone cortex → ~ bone l!lga).・Yes, G
S maX + and G S IDaX 2 each correspond to the maximum value of the peak portion. ΣGS corresponds to the total area of the shaded area of ("Bone Metabolism-1 4th
Vol., pp. 319-325 (1981)). In addition, G S 1 na As a specific example of a method for pre-pointing, there is a method shown in Figure 5, but there are also various methods for pre-pointing that apply the MD method (for example, Showa 59-893
5@Publication, JP-A No. 59-49743. JP-A-60-83646, JP-A-61-1095
Publication No. 57. Calculations similar to those described in JP-A-62-183748, etc. can also be applied. If the image storage means stores an image of the test bone and an image of the standard material before conversion, the image of the test bone may be converted into the thickness of the standard material by this calculation means. . Other examples of calculations in the calculation means include Japanese Patent Application Laid-open No. 1983-
As shown in Candidate No. 109557, the bone density distribution of long bones may be obtained from the measurement results obtained by performing preliminary needle measurements on each part of the long bones. The anterior needle measuring device of the present invention is characterized by having a configuration for implementing such a bone measuring method. FIG. 4 schematically shows a preferred embodiment of the front needle measuring device of the present invention. In this figure, the automatic reading function section 61 shows a light generating means (light source) that irradiates the X-ray photographic film, and a detecting means for detecting the intensity of the transmitted light from the light source that passes through the X-ray photographic film. The apparatus is equipped with an automatic film running means for automatically running the X-ray photographic film. Such a light source may be one that generates a spot of light, but usually a scanning means is required. In order to create a device with a small and simple structure, a strip-shaped light source that generates strip-shaped light is practically suitable.As a detection means, any device can be used as long as it can detect transmitted light and can automatically read it. However, when a strip-shaped light source is used, a strip-shaped sensor, that is, a line sensor is preferable, and a strip-shaped contact image sensor is particularly preferable for practical purposes.A roller is usually used as a means for transporting the film, and in particular, a strip-shaped contact image sensor is preferable for practical purposes. A pair of rollers sandwiched between them and rotating in opposite directions is preferably used, but other rollers may also be used.As an automatic film traveling means, the film may be moved at a speed that is compatible with the detection speed of the detection means. Any device may be used as long as it can run the X-ray photographic film at a predetermined speed, and the running mode may be continuous or intermittent.The front needle measuring device of the present invention includes: It is preferable to include an image storage means.The image storage means stores digital signals relating to the intensity of transmitted light in the image on the X-ray photographic film of the bone to be examined obtained by the above-mentioned automatic reading means and the position of the film. Any storage device may be used as long as it can store a data group corresponding to , or a data group related to an image converted to the thickness of the standard material, and its storage memory size is selected according to the purpose of the previous measurement. A specific example is a computer means such as an image memory of about 2 Mbytes for the measurement of the anterior needle of the first metacarpal bone.Furthermore, in the apparatus of the present invention, the determining means and the light amount adjusting means which operate as described above are: Input means, storage means. It is practically preferable to use computer means having necessary functions such as calculation means. That is, as shown in FIG. In addition to, an area search means, a first determination means, and a second determination means 1 connected thereto.
an MPU for performing each function of the generated light amount adjusting means;
It includes the corresponding functional part in ROM etc. The function of such an area search means is provided in the MPU, and may include means for storing a predetermined condition such as, for example, that the A/D conversion value of the amount of transmitted light corresponding to the amount of increase in thickness per step of aluminum stairs is 2 digits or more. preferable. The function of the first determination means is also provided in the MPU, and includes the aforementioned storage means for II and I2, storage means for 5IS2, and a necessary amount of comparison means. Furthermore, the function of the second determination means is also provided in the MPU,
Means is included for inputting and storing criteria for ΔI as described above. Also, one of the features of the device of the present invention
Regarding the generated light amount adjusting means, the adjusted light amount set value is determined by the MPU, and the illuminance is set by the LED controller. I l as mentioned above
It is necessary that the MPU is equipped with necessary functions such as input storage means for ax, calculation means for 111, and comparison means. Furthermore, using the ROM function as a means for pre-memorizing the contents of the first and second tables as described above facilitates efficient automatic adjustment. The apparatus of the present invention is also equipped with arithmetic means for performing various processes for bone measurement using images read from the film. The apparatus of the present invention also includes a CRT for displaying as an image the image of the bone to be examined read by the image reading means or stored by the storage means, as shown in FIG.
(Cathode Ray Tube); a point input means for inputting reference points necessary for bone measurement in the displayed image of the bone to be examined; This includes an apparatus having a calculation means for performing calculations for bone measurement regarding an image of a bone examination. Such image display means may be of any kind as long as it can display as an image a data group consisting of the relationship between digital signals and positions stored in the image storage means or obtained by the automatic reading means. Specifically, a CRT or the like is a preferable example in terms of the cost of resolution. The point input means may be any device as long as it can specify and input a position as a reference point on the image display means, and a specific example is a cursor as shown as 4 in FIG. Examples include a method of external input using a position display and instruction control means, a light pen type input means, a touch panel, and a method of automatically inputting from a stored image of the bone to be examined. For example, before adjusting the light intensity of the light source, the device of the present invention includes:
The position of the reference point input by the point input means in the image display means is stored in a RAM as shown in FIG.
Then, the same portion of the film is read again using the adjusted light amount after adjusting the light amount based on the determination result as described above, and the image displayed on the display means is stored in the RAM. Included are those having means for inputting points based on reference points. These series of operations are performed by the image reading function section 6 operated under the control of the MPU in FIG.
It is done in 1. With this configuration, if the irradiation light intensity is reset and differs from the previous setting, the film is automatically fed to the aluminum stairs and the target area, and if the point input of the target area is required, the previous point input is performed. Since the value is memorized and processing is automatically performed at that location, the burden on the operator for re-entering can be reduced. Furthermore, the bone measurement output means in the bone measurement device of the present invention may be any device as long as it can output the measurement results obtained by calculation, and specific examples include a dot-type ink printer for hard copies, Thermal printers include laser printers, video printers, and other CRT screens. In addition, in the reading function section 61 shown in FIG. 4, for example, 65μ
Pitch x line sensor (CC) consisting of 4096 elements
D: charge coupled device
) are lined up perpendicularly to the film movement direction, and a band-shaped light source (LED: li
The film is irradiated by a X-ray film (e.g. ght elittinljdiode), and the transmitted light is focused on the film's reflective surface by a rond lens placed so as to focus on the line sensor, and the intensity of the transmitted light is determined according to the density of the X-ray film. It is equipped with a minute film transport means using a pulse motor that can obtain a signal and at the same time move minutely at a pitch of 65 microns in a direction perpendicular to the line sensor and the band-shaped light source. Further, each element of the line sensor outputs an analog voltage signal proportional to the amount of light incident on the line sensor (=the amount of transmitted light according to the lightness of Al on the film). Line sensors, band-shaped light sources, and rond lenses have variations in characteristics between elements in the width direction, so T D S P (D igtital S 1 (l
nalprocessor), RE F (RE
F data storage section) and A/D conversion section>. A control means for enabling the detection of transmitted light in a specific region of the X-ray photographic film and for controlling the film to run intermittently at a predetermined speed is shown as a film feed controller in FIG. Illustrated. The COD driver shown in FIG. 4 has a function of controlling the data stored in the CCD so that it can be retrieved at a predetermined timing. In the pre-needle measurement data processing function section 62 in FIG. 4, the data group read by the automatic reading section 61 is stored by an image storage means mainly consisting of an image input/output section and an image memory in the data processing section 62. Data regarding the stored images are displayed by the CRTC and CRT. Finch CR with image display means and point input means
T (640 dots x 400 lines) displays an image of the metacarpal bone, and in order to specify the measurement site, the cursor is moved to indicate the bone head/anterior end.Such point input means are as follows:
In FIG. 4, it is shown as a KB I/F and a keyboard. The calculation for the front needle measurement is performed in the calculation means mainly consisting of ROM (program storage unit for calculations) and RAM (portion for performing calculations and storing results) shown in FIG. 4. The measurement results are outputted by the output means mainly consisting of the PRI/" and the printer in FIG. 4. The RS-232c and MODEM are for connecting with other devices. The MPU in FIG. In addition to the above functions, the PIO is a 16-bit microprocessor that imports data into the image memory, starts and stops programs, and controls the keyboard, CRT, etc. [Effects of the Invention] According to the bone measurement method of the present invention, by correcting the amount of irradiation light using a method that is practically easy to operate, XJ can be measured over a wide range of brightness, which was previously difficult. !The front needle measurement device of the present invention enables the front needle measurement of photographic film.
Pre-needle measurements on radiographic films with a wide range of brightness,
This is made possible by a simple operation for correcting the amount of irradiated light, and is excellent in practice.

[Brief explanation of drawings]

FIG. 1 illustrates the arrangement of a subject during X-ray photography to obtain the X-ray photographic film used in the present invention. FIG. 2 schematically illustrates the automatic reading means in the apparatus of the present invention. FIG. 3 schematically illustrates calculations for pre-pointing that can be performed in the device of the invention. FIG. 4 schematically illustrates the apparatus of the present invention in the form of a block diagram. FIG. 5 is a flowchart schematically illustrating the determination and light amount adjustment used in the method and apparatus of the present invention. Figure 1

Claims (9)

[Claims] (1) In a method of measuring a test bone using the amount of transmitted light obtained by irradiating light onto an X-ray photographic film of a test bone taken together with a standard material of varying thickness, the reference material Find a region whose amount of transmitted light satisfies a predetermined condition, and perform a first determination as to whether or not the range of amount of transmitted light for the part to be measured falls within the range of amount of transmitted light for the reference material in the region. Further, a second determination is made as to whether the amount of transmitted light of the measurement target portion and the corresponding amount of transmitted light of the standard substance satisfy a predetermined resolution, and the X-ray photographic film is irradiated based on the determination result. A bone measurement method characterized by adjusting the amount of light. (2) The bone measurement method according to claim 1, wherein after performing the second determination, a third determination is made as to whether or not the γ value of the measurement target portion is equal to or greater than a predetermined value. (3) The bone measuring method according to claim 1, wherein the adjustment of the amount of irradiation light is the adjustment of the light irradiation time. (4) When increasing the amount of irradiation light, find the amount of transmitted light I for the standard material that is larger than the maximum amount of transmitted light for the measurement target part and close to the maximum amount of transmitted light, and calculate the amount of transmitted light I
2. The bone measuring method according to claim 1, wherein the amount of irradiation light is adjusted so that Imax does not exceed a predetermined value Imax and becomes close to the predetermined value Imax. (5) When lowering the irradiation light amount, a region exceeding a predetermined value Imax is found in the measurement target portion, an appropriate irradiation light amount is estimated from the size of this region, and the irradiation light amount is adjusted. Bone measurement method. (6) Using the amount of transmitted light obtained by irradiating an X-ray photographic film obtained by irradiating X-rays to the bone to be examined together with a reference material of varying thickness, the image in the film is determined. a reading means for reading, an image storage means for storing the read image of the bone to be examined, a calculation means for performing calculations for bone measurement on the stored image of the bone to be examined; A bone measurement device comprising a bone measurement output means for outputting the obtained bone measurement results,
The reading means includes a light generation means for generating light to be irradiated onto the X-ray photographic film, a detection means for detecting the amount of transmitted light, and an area where the amount of transmitted light satisfies a predetermined condition for the standard substance. a region search means for determining the amount of transmitted light of the measurement target portion; a second determination means for determining whether the amount of transmitted light of the standard substance corresponding to the reference substance satisfies a predetermined resolution; and a generation for adjusting the amount of light generated by the light generation means based on the determination result by the determination means. 1. A bone measuring device comprising a light amount adjusting means. (7) The bone measuring device according to claim 6, further comprising means for determining whether the gamma value of the measurement target portion is equal to or greater than a predetermined value. (8) When increasing the amount of generated light, a means for determining the amount of transmitted light I of a part of the standard material that is larger than the maximum amount of transmitted light and close to the maximum amount of transmitted light for the part to be measured; A means is provided for adjusting the amount of generated light so that it does not exceed the value Imax and is close to the predetermined value Imax, and when further reducing the amount of generated light, the area of the measurement target portion that exceeds the predetermined value Imax is 7. The bone measuring device according to claim 6, further comprising means for determining the amount of irradiation light, and means for estimating an appropriate amount of irradiation light from the size of the region and adjusting the amount of irradiation light. (9) an image display means for displaying an image read of the subject bone as an image; a point input means for inputting necessary reference points in the displayed image of the subject bone; having means for storing the position of the reference point, and further automatically running the film when adjusting the light intensity and remeasuring the film;
Claim 6, further comprising means for automatically reading an image of the reference material and the measurement target part with the adjusted light intensity and inputting a point based on the stored reference point.
bone measuring device.