JPH04174650A - Bone measurement and device therefor - Google Patents

Abstract

PURPOSE:To carry out the bone measurement for an X-ray photograph film having a wide range of illuminance by using a means for adjusting the generated light quality of a light generating means according to the state of the X-ray photograph film when an image is read out. CONSTITUTION:Preparatpry light quantity adjustment (first light quantity adjustment) is carried out. The relation between the position and thickness of an aluminium step is calculated, and the standard thickness R1 is determined from the previously inputted ID data for an inspected person. After the first light quantity adjustment, the reading- out of the B region of the aluminium step and the data processing are carried out, and after scanning for a middle hand bone part as an inspected part is carried out, the execution of the algorithm for the middle hand bone data processing including the first and second judgement, second light quantity adjustment, etc., is carried out. Accordingly, when correction for eliminating the influence of the change of the characteristic such as sensitivity unevenness and illuminance unevenness of the LED and CCD through the lapse of time is carried out when a reading-out means is used, it is desirable in the actual use to adjust the radiation light quantity by varying the radiation time without varying the radiation light intensity, and the bone measurement of a film having a wide range of illuminance can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Separation] The present invention relates to a needle position measuring method and a bone measuring device. More specifically, the present invention provides an improved method and apparatus for measuring bone morphology and the like using images in an X-ray photographic film of a bone to be examined.

[Prior art] Various methods such as confirming the state of human bone growth and the degree of aging, and confirming the range of types of bone lesions such as osteoporosis and osteomalacia, the degree of progression of their symptoms, and the effectiveness of treatment. Bone measurements may be performed.

Such bone measurement methods include the MD method (" Bone Metabolism” Volume 13, 187
-195 pages (1980), "Bone Metabolism" Vol. 14, 9
1-104 (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 employ in that it uses an X-ray photographic film that can be easily obtained using an X-ray imaging device that is widely used as a device for diagnosing fractures, etc., and is becoming increasingly popular. Furthermore, photon absorption geometry
Regarding this, the equipment that generates gamma rays used is X11.
It is hard to say that they are more widely used than m-shadow devices.

[Problems to be Solved by the Invention] Conventional bone measurements using the M[) method have 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 Bone i! according to the established method using points! Select a site (for example, a site on the transverse line at the central point of the long axis of the first metacarpal) on which tm will be performed in detail. Next, while scanning the selected area with a microdecisitometer, 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 write a miniature map of the graph 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 diagrams 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 thus converted diagram, various indicators representing the bone shape at the target site are calculated within the computer, and the calculation results are output.

In addition, with regard to bone measurement using the conventional MD method, the degree of shading of the image of the bone to be examined on the obtained X-ray photographic film tends to change greatly due to variations in the X-ray photography conditions and film processing conditions. If the photographic film is extremely dark or bright, there is a problem in that measurements cannot be made, or even if measurements can be made, the error will be very large.

[Means for Solving Problem 11] As a result of intensive research in order to solve the problems in the prior art, the present inventors discovered that the transmitted light was obtained by irradiating light onto an image of a bone to be examined, etc. on an X-ray photographic film. The present invention was achieved by discovering that it is effective to use means for adjusting the amount of light generated by the light generating means depending on the condition of the X-ray photographic film when reading the image by detecting the X-ray film. .

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 bone to be examined photographed together with a standard material of varying thickness. In the method of measuring bone specimens, the reference thickness R1 of the standard material is determined from a predetermined relationship based on the gender and age of the specimen bone, and the standard thickness R1 of the standard material in the X-ray photographic film is determined. The amount of transmitted light I R1 for the reference thickness R1 is calculated, and the amount of transmitted light I R+ is determined as the predetermined amount of transmitted light 1 wax
This includes a bone measurement method characterized in that the irradiation light is adjusted so as not to exceed Iax and to be close to Iax.

The present invention also includes measurement of the bone to be examined using the amount of transmitted light obtained by irradiating light onto an X-ray photographic film of the bone to be examined, which has been photographed together with a standard material of varying thickness. In this method, a standard thickness R1 of the standard material is determined in advance based on the sex and, if necessary, the age of the subject, and the amount of transmitted light for the standard thickness R1 of the standard material in the X-ray photographic film is determined in advance. Find I R+ and calculate the amount of transmitted light I R+
A first light amount adjustment is performed to adjust the irradiation light amount so that the amount of irradiated light does not exceed a predetermined transmitted light 111aX and becomes close to the predetermined transmitted light 111aX, and then, for the standard material, a region where the amount of transmitted light satisfies a predetermined condition is determined. A first determination is made as to whether or not the range of the amount of transmitted light for the measurement target part falls within the range of the amount of transmitted light for the standard material in the area, and the range of the amount of transmitted light for the measurement target part is roughly determined. A second determination is made as to whether the amount of transmitted light of the standard substance satisfies a predetermined resolution, and based on the determination result, a second light amount adjustment is performed to adjust the amount of light irradiated to the X-ray photographic film. Includes bone measurement methods characterized by

This invention includes a bone measurement method in which, after performing the second determination, a third determination is made as to whether the γ value of the measurement target portion is greater than or equal to a predetermined value.

In the bone measurement method of the present invention, when increasing the amount of irradiation light,
Greater than the maximum amount of transmitted light for the part to be measured, and
It is desirable to determine the amount of transmitted light for a standard substance that is close to the maximum amount of transmitted light, and to adjust the amount of irradiation light so that the amount of transmitted light l does not exceed a predetermined value liax and becomes close to a predetermined value 1wax.

Furthermore, when lowering the amount of irradiation light, it is desirable to find the area of the measurement target part that exceeds a predetermined value of 1 gtax, estimate the appropriate amount of irradiation light from the size of this area, and adjust the amount of irradiation light. .

Furthermore, the present invention uses the amount of transmitted light obtained by irradiating light onto an X-ray photographic film obtained by irradiating X-rays onto the bone to be examined together with a reference material of varying thickness. 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 performing bone measurement on the stored image of the bone to be examined. A bone measurement device comprising a calculation means and a bone measurement output means for outputting the bone measurement results obtained by the calculation, the bone measurement device comprising a calculation means for outputting the bone measurement results obtained by the calculation, the bone measurement device comprising: It has a means for inputting information and a means for determining a reference thickness R1 of the standard material corresponding to the inputted patient information, and the reading means generates light to irradiate the X-ray photographic film. a light generating means for detecting the amount of transmitted light; a detecting means for detecting the amount of transmitted light; and a first light amount adjusting means for adjusting the amount of irradiated light so as to be close to said 1 wax, a region searching means for searching for a region in which the amount of transmitted light of said standard material satisfies a predetermined condition, and said standard material in said region. a first determination means for determining whether the range of the amount of transmitted light for the measurement target part is within the range of the amount of transmitted light for the measurement target part; It has a second determining means for determining whether a predetermined resolution is satisfied or not, and a second optical action adjusting means for adjusting the amount of light generated by the light generating means based on the determination result by the determining means. Included is a bone measuring device characterized by the following.

The reading means includes a bone measuring device further comprising means for determining whether the γ value of the measurement target portion is equal to or greater than a predetermined value.

In these bone measuring devices of the present invention, when increasing the amount of light generated by the second optical action adjustment means, the amount of transmitted light at a certain part of the standard material is larger than the maximum amount of transmitted light for the measurement target area and close to the maximum amount of transmitted light. Means of finding and transmitted light 11
does not exceed the predetermined value 1 wax and the predetermined value 1 wax
comprising means for adjusting the amount of generated light so that it approaches the amount of light generated;
In order to further reduce the amount of light generated, it is equipped with means for determining the area of the measurement target area that exceeds a predetermined value I■ax, and means for estimating an appropriate amount of irradiation light from the size of this area and adjusting the amount of irradiation light. Preferably, it is made to last.

The apparatus of the present invention also includes an image display means for displaying an image read of the bone to be examined as an image;
It has point input means for inputting a necessary reference point in the displayed image of the bone to be examined, and means for storing the position of the input reference point, and further adjusts the amount of light and remeasures the film. In some cases, it is preferable that the film be equipped with a means for automatically running the film, automatically reading images of the standard material and the measurement target area using the adjusted light intensity, and inputting points based on the memorized reference points. Included as a measuring device.

The present invention will be explained in more detail below.

The image of the bone to be examined on the X-ray photographic film in the present invention is
It mainly refers to the degree of darkening and shape of the bone to be examined on film. As the standard material with varying thickness, an aluminum staircase is usually used, but a tube-shaped aluminum member or the like may also be used. The bone to be examined may be any bone that can provide an X-ray photographic film with a certain degree of clear shading, but it is usually desirable to have a thin, even soft tissue layer. More specifically, long canals such as the proximal and humerus, the radius, the 9 ulna, the femur, the tibia, and the fibula may be mentioned, and among them, the 1st metacarpal is practically preferred.

Examples of other bones include the calcaneus, the vertebrae, and the epiphyses of long bones, among which the calcaneus is practically preferred.

FIG. 1 shows an example of the arrangement when performing xm photography with aluminum stairs in the foreground. In the same figure, 10
is a dry plate for X-ray photographic film, 11 is an aluminum staircase, 12 and 13 are the right hand and left hand, respectively, and 14 is the
It is a metacarpal bone.

FIG. 2 schematically shows an example of such an automatic reading means for an X-ray photographic film, in which 20 is an X-ray photographic film, 21 is an image of a button bone,
22 is a strip light source, and 23 is an A5 image sensor.
24 indicates a roller for running the film.

FIG. 5 is a schematic flowchart showing a preferred embodiment of the nine measurement methods of the present invention. That is, as shown in FIG. 5, first, at least the gender and, in the case of a female, the age of the subject are input into the bone measuring device as subject information (ID data). Specific examples of such input include reading a display such as a bar code on an X film, and input using a key bunch. Next, reading the image of the X-ray photographic film is started, and by first performing a rough reading of the entire film, areas to be read in detail are selected for each of the reference material and the test bone (the specific method of rough reading is described in the patent application). (Refer to the specification of Hei 2-25808).

After that, for example, the left half of the image of the aluminum step 11 as a standard material shown in FIG. Scan the image and read the amount of transmitted light. At that time, the edges of the image of the aluminum stairs are automatically detected and the correspondence relationship between the position and thickness of the image of the aluminum stairs is recognized.
-25809 specification).

Next, preliminary light amount adjustment, which is a major feature of the present invention
(also referred to as the first light amount adjustment). FIG. 6 is a flowchart showing details of one example of such first light amount adjustment. That is, as shown in FIG. 6, the relationship between the position and thickness of the aluminum step is first calculated, and the reference thickness R1 is determined from ID data regarding the subject input in advance. Regarding R1, for example, in the case of Japanese metacarpal bones, analysis results of numerous X-ray photographs show that R1 is R+ for men regardless of age.
-10111, R1 = 9- for women under 70 years old
It can be said that the present invention was achieved by discovering that it is appropriate to set R+ = 8 mm for people over 70 years old. Note that R1 may be changed to another value by performing similar analysis depending on the target. The amount of transmitted light I -250
) and IRl, and if IR1 is smaller than IWaX, increase the illuminance set value amount to Q+1 based on the relationship between the memorized irradiation light amount and irradiation time as described later (see Table 2). is estimated by the proportional relationship, and its 'I' R1
Repeat the comparison of and l wax as necessary,
After setting I R+ or I R1 to be larger than l laX, set it one step lower than the current illumination polish (1-1
＞ is the illuminance sentence after adjustment.

After the first light intensity adjustment, the area B of the aluminum step in FIG. The first characteristic of The process proceeds to the execution of the metacarpal data processing algorithm including the second determination and the second light amount adjustment.

The first aspect of the present invention. The second determination is to search for a region on the X-ray photographic film in which the amount of transmitted light of the standard material satisfies a predetermined condition, find the range of the amount of transmitted light of the standard material corresponding to that region, and calculate the amount of transmitted light of the standard material. A first determination is made as to whether or not the amount of transmitted light for the bone measurement target portion is within the range, and whether the amount of transmitted light of the reference material corresponding to the amount of transmitted light of the measurement target portion satisfies a predetermined resolution. A second determination is made as to whether or not the irradiation occurs, and the amount of second irradiation light is adjusted based on the determination result.

The following method can be cited as a specific example of such determination and second light amount Ill. That is, as shown in Fig. 7, the amount of transmitted light for the image of the aluminum stairs on the X-ray photographic film that has been run to a predetermined position is determined by the amount of light determined in advance according to the gender and age of the subject for bone measurement. demand.

Based on the relationship between the amount of transmitted light and the thickness of the aluminum staircase, an area that can be effectively measured as an aluminum staircase, that is, an area that can be broken down into steps, is determined. In order to effectively measure aluminum stairs, for example, when the amount of transmitted light is converted by an A/D (analog/digital) converter,
From the bit error of D, the value after A/D conversion of the amount of transmitted light corresponding to the thickness of one step of aluminum stairs needs to be 2 digits or more. Of course, it goes without saying that the amount of transmitted light must not be saturated. The area of this aluminum staircase is determined, and the amount of transmitted light for the aluminum staircase at the upper limit of the area is set to 1+, and the amount of transmitted light for the aluminum staircase at the lower limit of the area is set to 12. Next, the maximum value of the amount of transmitted light for the measurement target part of the test bone is SI,
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≧12, and if this condition is not met, the amount of irradiated light is too small and needs to be increased. However, if SI>I+ and 82<12, no matter how much the light amount is changed, the measurement cannot be performed, so it is determined that the 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 82≧I2 are satisfied. That is, the amount of transmitted light of the aluminum staircase is close to the amount of transmitted light of SI, preferably the closest < SI, and the amount of transmitted light of the aluminum stairs is 1 + ' + 52 (preferably, the amount of transmitted light of the aluminum stairs is smaller than the closest < 82 is I2'). Find the value after A/D conversion that corresponds to the thickness of each step of the aluminum stairs in the region It' to 12', and set the minimum value as ΔI.For example, here, the thickness of one step of the aluminum stairs If a total of 1llIIflK and a resolution of 0.2III or less are required, 5 digits (dig days) or more, preferably 7 digits or more are required.

For example, if 7 digits are required, it is determined whether Δ1≧7. If this condition is met, it is determined that the amount of irradiation light is suitable for X-ray film, and subsequent operations necessary for bone 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 1+' is adjusted to be close to the predetermined level Iwax without exceeding it, preferably to the closest value, and re-measurement is performed. At this time 1
giax is the saturation level of the sensor or AD converter at 95
It is preferable to set it to about 98%.

On the other hand, if the amount of irradiated light is too large, 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 bone measurement for the second metacarpal bone, this count number and (
The relationship between the amount of irradiated light (amount of irradiated light - appropriate amount of irradiated light) is approximately 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 Igaax is O, the transmitted light 11o, which is equivalent to an aluminum step one step thicker than 11, is I+.

The amount of transmitted light I I 12 corresponding to an aluminum step one thickness thinner than 11 is small, and the amount of transmitted light 113 corresponding to an aluminum step two thickness thinner than 11 is In −1+ .
-2,5(Iν+■13), and this amount of transmitted light I
The irradiation light is changed so that n does not exceed lwax but becomes close to it, preferably as close as possible.

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 γ value γ, which represents the change in OD (absorbance) with respect to the change in relative exposure amount, is 1+' to 12.
Since the measurement can be performed with high accuracy only when the minimum value obtained for each step in the region of ' exceeds the predetermined value γ0, it is preferable to combine this with the determination of resolution. Here, γ is preferably 1 to 4, and γ0 is preferably in the range of 1 to 2, for example.

As a method of adjusting the irradiation light aperture, there is a method of adjusting the irradiation time by changing it. For example, as a means for generating irradiation light, a band-shaped LED (light elittin9di
COD as a transmission-first detection means.
When a line sensor consisting of (charge coupled devtce) is used, it is possible to adjust the irradiation time by controlling the number of small responsive pulses lit in the LED using a pulse generator.

In the present invention, for example, when using a reading means using an LED or COD, if correction is performed to eliminate the influence of changes over time in the characteristics of the LED or COD, such as sensitivity unevenness and illuminance unevenness, In order to make such correction more effective, it is practically desirable to adjust the amount of irradiated light by changing the irradiation time without changing the irradiated light intensity.

As a specific method for adjusting the irradiation light amount by changing the irradiation time, it is practical to store a table as shown in Table 2 in the storage means and change the illuminance setting value (dan) corresponding to the irradiation time. This is advantageous in terms of improving efficiency.

Table 2 and Figure 3 show a concrete example of the content of calculations for bone measurement according to the present invention. The corresponding thickness is displayed as a pattern. That is, D indicates the bone width, and the shaded area represents the bone density distribution.

d, d2 indicate the bone cortex width, and d indicates the bone marrow width.

G51n has a beak of 40. It corresponds to the minimum value of the valley 42 between the beaks 41 and indicates the density of (bone cortex + bone marrow), and G51aX + and G55ax 2 each correspond to the maximum value of the peak. ΣGS corresponds to the total area of the shaded area regarding the width (see "Bone Metabolism", Vol. 4, pp. 319-325 (1981)). In addition, G S laX 2 etc. in FIG. 3 represent the difference in the number of steps of the aluminum stairs corresponding to the difference in the amount of transmitted light in the actual bone measurement target portion described above, expressed by the thickness of the aluminum stairs.

Specific examples of calculations for bone measurement include various methods of bone measurement applying the MD method (for example, Japanese Patent Application Laid-Open No. 59-8935, Japanese Patent Application Laid-Open No. 59-49743, Japanese Patent Application Laid-Open No. 60-8).
3646, JP-A-61-109557, 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. .

Another example of a scale in arithmetic means is disclosed in Japanese Patent Application Laid-open No. 1983-
As shown in Candidate No. 109557, the bone density distribution of the hipbone may be obtained from the measurement results obtained by performing bone measurements on each part of the long canal.

The bone 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 bone measuring device of the present invention. In this figure, the automatic reading function section 61 includes a light generating means (a light source) for irradiating the X-ray photographic film, and a detection 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 automatic film transport means for automatically transporting the X-ray photographic film.

Such a light source may be one that generates spot-shaped light, but usually a scanning means is required, and in order to make it a small and simple structure, a strip-shaped light source that generates strip-shaped light is used. is suitable for practical use. Further, as the detection means, any device may be used as long as it can detect transmitted light and automatically read it, but 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. Practically preferred. Rollers are usually used as the film traveling means, and a pair of rollers rotating in opposite directions with the film sandwiched therebetween is preferably used, but other means may be used.

The automatic film running means may be of any type as long as it can run the X-ray photographic film at a predetermined speed that is compatible with the detection speed of the detection means, and the running format may be continuous. It may also be intermittent.

Preferably, the bone measuring device of the present invention includes image storage means. Such an image storage means may be a data group in which a digital signal regarding the intensity of transmitted light in an image of an X-ray photographic film of a bone to be examined obtained by the above-mentioned automatic reading means corresponds to the position of the film, or a standard material. Any device may be used as long as it can store a group of data related to images converted to the thickness of , and the storage memory size is selected depending on the purpose of bone measurement. As a specific example, computer means such as an image memory of about 2 Mbytes may be used for bone measurement of the 1st metacarpal bone.

Further, in the apparatus of the present invention, the determining means and the light amount adjusting means that operate as described above are an input means and a storage means.

It is practically desirable to use computer means having necessary functions such as calculation means.

That is, as shown in FIG. 4, the reading means in the apparatus of the present invention includes, in addition to the automatic reading function section 61, an area search means, a first determination means, and a second determination means 9 connected thereto.
MPLJ for fulfilling each function of the generated light amount adjustment means
, ROM, and the like. The function of the search area search means is provided in the MPU,
For example, it is preferable to have means for storing a predetermined condition such as an A/D converted value of the amount of transmitted light corresponding to the amount of increase in thickness per step of aluminum stairs of 2 digits or more. Further, the function of the first determination means is also provided in the MPU, and the storage means of II, 12, and Sz as described above.

It includes a means for storing Sz and a means for comparing the necessary amount.

Furthermore, the second determination means is also provided in MPJJ, and includes means for inputting and storing the determination criteria for ΔI as described above. Regarding the generated light amount adjusting means, which is one of the features of the device of the present invention, the adjusted light amount set value is determined by the MPU, and the illuminance is set by the LED controller. As mentioned above
It is necessary that the MPU is equipped with necessary functions such as input storage means for g+ax, calculation means for 111, and comparison means. Furthermore, as mentioned above, the first. Using the ROM function as a means for pre-memorizing the contents of Table 2 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.

Furthermore, as shown in FIG. 4, the apparatus of the present invention displays the image of the bone to be examined read by the image reading means or stored by the storage means as an image.
An image display means such as a Cathode Ray Tube (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, and a point input means for inputting reference points necessary for bone measurement in the displayed image of the examined bone; The apparatus includes a calculation means for performing calculations for bone measurement regarding an image of a bone to be examined.

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 inputting from the outside using a position display and instruction control means, a light-ben 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 amount is reset and it differs from the previous setting, the film is automatically fed to the aluminum stairs and the target area, and if it is necessary to input the point of the target area, the previous point input value is used. Since the information is memorized and processed automatically at that location, the burden on the operator for re-inputting 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, Examples include thermal printers, laser printers, video printers, and other CR7 screens.

In addition, in the reading function section 61 shown in FIG. 4, for example, 65μ
PitzchiX 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 emitting diode), and the transmitted light is focused by a Rondo lens placed on the line sensor to focus the transmitted light on the film's reflective surface. 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. 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 density of the film).

Line sensors, strip light sources, and rond lenses have variations in characteristics between elements in the width direction, so DSP (Digital S 1 ona) is used as a correction means for this.
1Processor), REF (REF data storage unit), and A/D conversion unit).

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 bone 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, moves the cursor to specify the measurement site, and indicates the femoral head/end. Such point input means are
In FIG. 4, it is shown as a KB I/F and a keyboard.

Calculations for bone measurement are performed in the calculation means shown in FIG. 4, which is mainly composed of a ROM (a program storage unit for calculations) and a RAM (a part that performs calculations and stores results).

The obtained bone measurement results are outputted by the output means mainly consisting of the PRI/F and printer shown in FIG. RS-232c and MODEM are for connecting to other devices.

In addition to the above-mentioned functions, MPtJ in FIG.
The PIO, which is a 16-bit microprocessor that controls the computer, keyboard, CRT, etc., functions as an interface for inputting and outputting digital control inputs and outputs to the computer system.

[Effects of the Invention] According to the bone measurement method of the present invention, the amount of irradiation light can be efficiently corrected using a method that is practically easy to operate, thereby making it possible to measure bones on X-ray photographic films with a wide range of brightness, which was previously difficult. Measurement can be made possible. Furthermore, the bone measuring device of the present invention is excellent in practical use, as it enables bone measurement on X-ray photographic films with a wide range of brightness using a simple and efficient irradiation light amount correction means.

[Brief explanation of drawings]

FIG. 1 shows the XI film for obtaining the XI photographic film used in the present invention! This is an example of the arrangement of a subject when photographing. FIG. 2 schematically illustrates the automatic reading means in the apparatus of the present invention. FIG. 3 schematically illustrates calculations for bone measurement that can be performed in the apparatus of the present invention. FIG. 4 schematically illustrates the apparatus of the present invention in the form of a block diagram. FIG. 5 illustrates a flowchart of preliminary operations, including preliminary illumination adjustment, used in the method and apparatus of the present invention. FIG. 6 illustrates a flowchart for such preliminary (or first) illuminance adjustment according to the present invention. FIG. 7 is a flowchart schematically illustrating the determination and light amount adjustment used in the method and apparatus of the present invention. Patent applicant Teijin Ltd. No. 1
Figure 2 Figure 2o□ Figure 3 Figure 6

Claims (5)

[Claims] (1) In a method of measuring the test bone using the amount of transmitted light obtained by irradiating light onto an X-ray photographic film of the test bone of a test subject photographed together with a standard material of varying thickness. ,
The reference thickness R_1 of the reference material based on the sex and age of the test bone is determined from a predetermined relationship, and the reference thickness R of the reference material in the X-ray photographic film is determined.
The amount of transmitted light I_R_1 for _1 is determined, and the amount of transmitted light I_R_1 does not exceed the predetermined amount of transmitted light Imax and the amount of transmitted light I_R_1 does not exceed the predetermined amount of transmitted light Imax.
A bone measurement method characterized by adjusting the amount of irradiation light so as to be close to the maximum. (2) In a method of measuring the test bone using the amount of transmitted light obtained by irradiating light onto an X-ray photographic film of the test bone of the test subject, which has been photographed together with a standard material of varying thickness. ,
A standard thickness R_1 of the standard material is determined in advance based on the sex and, if necessary, the age of the subject, and the amount of transmitted light I_R_1 for the standard thickness R_1 of the standard material in the X-ray photographic film is determined; A first light amount adjustment is performed to adjust the irradiation light amount so that the transmitted light amount I_R_1 does not exceed a predetermined transmitted light amount Imax and becomes close to the Imax, and then the transmitted light amount of the standard substance satisfies a predetermined condition. A first determination is made as to whether or not the range of the amount of transmitted light for the measurement target part is within the range of the amount of transmitted light for the standard material in the area, and then the amount of transmitted light for the measurement target part and the amount of transmitted light for the measurement target part are determined. A second amount of light for making a second determination as to whether or not the amount of transmitted light of the corresponding standard substance satisfies a predetermined resolution, and adjusting the amount of light irradiated to the X-ray photographic film based on the determination result. A bone measurement method characterized by adjustment. (3) The bone measuring method according to claim 2, 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. (4) Using the amount of transmitted light obtained by irradiating light on an X-ray photographic film obtained by irradiating X-rays to the test bone of a subject together with a reference material of varying thickness, a reading means for reading an image therein; an image storage means for storing the read image of the bone to be examined; and a calculation means for performing calculations for bone measurement on the stored image of the bone to be examined. and a bone measurement output means for outputting the bone measurement results obtained by calculation, the bone measurement device is provided with patient information regarding the sex of the patient and, if necessary, age. and a means for determining a standard thickness R_1 of the standard material corresponding to the input patient information, and the reading means has a light source for generating light to irradiate the X-ray photographic film. a generating means, a detecting means for detecting the transmitted light amount, and a transmitting light amount I_R_1 determined for the reference thickness R_1 of the standard material in the X-ray photographic film does not exceed a predetermined transmitted light amount Imax and is within the Imax. a first light amount adjustment means for adjusting the amount of irradiated light so that the amount of light transmitted by the reference material is close to that of the reference material; a first determination means for determining whether or not a range of the amount of transmitted light for the measurement target portion falls within the range; a second determination means for determining whether or not the
A bone measuring device comprising: second light amount adjusting means for adjusting the amount of light generated by the light generating means based on the determination result by the determining means. (5) The bone measuring device according to claim 4, wherein the reading means further includes means for determining whether the gamma value of the measurement target portion is equal to or greater than a predetermined value.