JPH10323344A - Test chart for evaluating and correcting ionizing radiograph, manufacture thereof, and method of evaluating and correcting ionizing radiograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To leave a test chart in the vicinity of affected part of an object body to evaluate and correct to specify the position and the size of the affected part from an image, by using the test chart to adjust the ionizing radiation absorptive coefficient and the film thickness on a sheet which does not absorb ionizing radiation or has a low ionizing radiation absorptive coefficient. SOLUTION: A test chart 10 uses a transparent adhesive PET film 12, which does not absorb X-ray or has a low X-ray absorptive coefficient, as the sheet for the substrate. A pattern of X-ray absorptive film 14 is printed by an ink, which is made by mixing metal powder into a binder, in a prescribed thickness containing a metal with a high X-ray absorptive coefficient on the processed face. The X-ray absorptive film 14 comprises regions with five gradations of X-ray absorptive coefficients as a whole, which are four divided regions 20A-20D respectively with a ring shape with the center angle of 90 deg. in plan view and a central transparent region 20E. Thereby, when the depth of the observed body tissue is estimated, the distance and the position can be evaluated and corrected from the correct size of the tissue in the horizontal direction and the chart pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for detecting an index in an image photographed in a subject or in the vicinity thereof, for example, in the case of X-ray photography in the medical field, or in the industrial field when photographing using gamma rays. A test chart for evaluating and correcting ionizing radiation imaging, a method for manufacturing the same, and a method for manufacturing the same, wherein the position and the size of a specific part of the subject can be easily specified from the captured image based on the index. It relates to an evaluation and correction method.

[0002]

2. Description of the Related Art A conventional test chart for this type of X-ray imaging evaluation / correction is disclosed, for example, in Japanese Patent Publication No. Sho 62-5377.
As disclosed in Japanese Unexamined Patent Publication No. 0, a plurality of test pieces made of a metal foil having a C-shape or an O-shape are arranged on a substrate made of a material having good X-ray transparency. The outer dimensions of the pieces are made to differ gradually in a predetermined direction, and further,
An X-ray photographic evaluation device is provided in which the thicknesses of the different external dimensions are sequentially and stepwise varied on the substrate in a direction different from the predetermined direction. There is a test chart. The thickness of the test piece is adjusted by superposition or etching, thereby changing the X-ray absorption coefficient.

Further, there are, for example, those disclosed in JP-A-61-248665 and JP-A-5-329141.

[0004] In the former, when a subject is X-ray photographed, a standard density chart is photographed by an imprinting device in addition to a photographing date, a subject name, and the like. Thus, the characteristic curve of the film is calculated.

In the latter, a standard phantom is arranged between a subject and an X-ray detector, and a measured value of the standard phantom calculated using an X-ray transmission image measured by scanning the X-ray detector is used. An X-ray diagnostic apparatus and a correction method for performing correction so that correct calculation can be performed.

[0006]

In the above-described conventional test chart, film image reading apparatus, X-ray diagnostic apparatus and correction method, the specified position of the subject is left as an index near the affected part under X-ray photography. Is difficult,
Even if it is left, it is necessary to evaluate and correct the X-ray image in accordance with various X-ray absorption characteristics of different affected tissues, thereby identifying the position and size of the affected area from the X-ray image. There was a problem that it was difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and leaves a specified position of an object as an index near an affected part under ionizing radiation imaging such as X-rays and γ-rays. An object of the present invention is to provide a test chart for ionizing radiation imaging evaluation and correction, and a method for manufacturing the same, in which this index can correspond to various ionizing radiation absorption characteristics of different affected tissues.

It is another object of the present invention to provide a method for evaluating and correcting ionizing radiation imaging using such a test chart.

[0009]

According to the present invention, there is provided an ionizing radiation absorption coefficient of a metal contained on a sheet which does not absorb ionizing radiation or has a low ionizing radiation absorption coefficient. By adjusting at least one of the amount and the film thickness, the ionizing radiation absorption coefficient is set to a predetermined standard, and the ionizing radiation imaging evaluation is formed by forming the ionizing radiation absorbing film in a pattern that can specify the size and the imaging direction.・
The above object is achieved by the correction test chart.

[0010] The radiation absorbing film may be formed by laminating a plurality of coating films having different patterns.

The ionizing radiation absorbing film may be divided into a plurality of regions, and each divided region may be formed of a coating film having a different ionizing radiation absorption coefficient.

The radiation absorbing film is formed in a ring shape;
The ring may be circumferentially divided into a plurality of regions, and each region may have a different ionizing radiation absorption coefficient.

Further, an outer peripheral region having a higher ionizing radiation absorption coefficient than the inner region may be formed along the outer peripheral edge of the pattern.

Further, the total thickness of the ionizing radiation absorbing film may be substantially equal over the entire surface.

Different ionizing radiation absorption coefficients may be obtained by making the thickness of the ionizing radiation absorbing film different for each different region.

An adhesive layer for attaching a sheet to a subject may be formed over the ionizing radiation absorbing film.

According to the present invention, an ink formed by kneading a metal powder having a high ionizing radiation absorption coefficient with a binder does not absorb ionizing radiation.
Or an ionizing radiation imaging evaluation characterized by printing an ionizing radiation absorbing film on a sheet with a low absorption coefficient in a pattern that can specify the size and imaging direction when attached to the subject.
The above object is achieved by a method of manufacturing a correction test chart.

When printing the ionizing radiation absorbing film, a region which does not absorb ionizing radiation or has a relatively low absorption coefficient may be formed.

The metal powder is composed of at least one of lead, bismuth, barium, tungsten, each compound, and a mixture thereof, and the binder is made of acrylic, urethane, vinyl chloride, polyester, or the like. Of these, at least one resin may be used.

The metal powder comprises at least one of lead, bismuth, barium, tungsten, each compound, and a mixture thereof; the binder comprises a photocurable resin; The pattern may be cured by irradiating the pattern with light.

The type of the metal powder, the P / V ratio of the ink,
The ionizing radiation absorption coefficient of the printed film may be adjusted by at least one of the printed film thicknesses.

The ionizing radiation absorbing film is formed by sequentially laminating a plurality of thin films having different patterns, and is formed from a plurality of regions having the same number of laminations of the different thin films. The total thickness of each region may be equal.

The ionizing radiation absorbing film may be formed by printing a plurality of thin films having different patterns sequentially on each other and forming the film from a plurality of regions having different numbers of laminated thin films, so that the ionizing radiation absorption coefficient of each region is different. Good.

According to another aspect of the present invention, a photoresist is provided on a metal plate having a high ionizing radiation absorption coefficient in a pattern capable of specifying a size and an ionizing radiation photographing direction when attached to a subject. Micro-printing, exposure, the thickness of the metal plate by etching, the pattern is divided into a plurality of regions, and adjusted so that a predetermined ionizing radiation absorption coefficient different for each region is obtained, the ionizing radiation absorbing film The above object is achieved by a method for producing a test chart for evaluating and correcting ionizing radiation imaging characterized by being formed.

After the ionizing radiation absorbing film is formed, a layer of a pressure-sensitive adhesive which can be attached to a subject may be formed by covering the ionizing radiation absorbing film.

According to a still further aspect of the present invention, there is provided an ion absorbing radiation absorption coefficient, a content and a film thickness of a metal contained on a sheet which does not absorb ionizing radiation or has a low ionizing radiation absorption coefficient. By adjusting at least one of the above, the ionizing radiation absorption coefficient is set to a predetermined standard, and a test chart formed by forming an ionizing radiation absorbing film in a pattern whose size and imaging direction are specified is irradiated with ionizing radiation. Attached on the ionizing radiation source side portion of the subject in the region and the bed on which the subject is placed, and after irradiation with ionizing radiation, based on the mass absorption coefficient and the ionizing radiation intensity distribution with respect to a fixed ionizing radiation source output inspected in advance. Then, by evaluating the size of the attached test chart and the contrast ratio of the image, the tissue and mass distribution in the subject, the position and size of the affected part, By ionizing radiation imaging evaluation and correction method characterized in that a constant is intended to achieve the above object.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

The test chart 10 for X-ray imaging evaluation and correction according to the first embodiment of the present invention shown in FIGS. 1 and 2 does not absorb X-rays or has a low X-ray absorption coefficient. For example, when the transparent easy-adhesion PET film 12 is used as a substrate sheet, its treated surface contains a metal having a high X-ray absorption coefficient, the film thickness is such that the X-ray absorption coefficient is a predetermined standard, and the size and the imaging direction are specified. X-ray absorption film 1 with different pattern
4 is formed, and further, an adhesive layer 16 is formed so that the outside can be adhered to the epidermis of a subject (for example, a human body),
Further, the adhesive layer 16 is covered with a release paper 18.

The X-ray absorbing film 14 has a ring shape in plan view and four divided areas 20A having a central angle of 90 °.
２０20D.

The thickness of each of the divided regions 20A to 20D is increased stepwise in this order.
The X-ray absorption coefficient is set to be four gradations step by step.

A small circular transmission region 20E made of the adhesive layer 16 and the PET film 12 is formed inside the ring-shaped X-ray absorbing film 14, so that the test chart 10 has five gradations as a whole. Of the X-ray absorption coefficient.

The metal having a high X-ray absorption coefficient contained in the X-ray absorption film 14 is lead, bismuth, barium, tungsten, a compound thereof, or a mixture thereof.
In any case, a powdery material is mixed with a binder and printed as a pattern on the PET film 12 as an X-ray blocking ink.

Alternatively, the metal powder is mixed with a binder made of a photocurable resin to form an X-ray blocking ink, and after pattern printing, light is irradiated from a curing light source to cure the pattern.

The binder is made of at least one resin selected from acrylic, urethane, vinyl chloride, and polyester. The photo-curable resin as the binder is, for example, urethane acrylate, polyester acrylate or a mixture thereof which is cured by ultraviolet rays.

The above-mentioned metal powder, binder, solvent, and P / V ratio are, for example, as shown in Table 1 below.

[0036]

[Table 1]

Next, a method of manufacturing the test chart 10 will be described.

First, the X-ray blocking inks 〜 as shown in Table 1 are kneaded with three rolls from the screen printing ink SS.

Next, a silk screen plate (Tetron 150 mesh, manufactured by Mino Group) having a pattern P1 shown in FIG.
On a treated surface of a 100 μm-thick transparent easy-adhesion PET film (manufactured by Toray Industries, Inc.), a coating film thickness of 110 μm is printed. The reference numeral h1 in FIG. 3 indicates a blank portion (hole).

The film thickness and the state of the coating film were confirmed with a laser focus displacement meter (manufactured by Keyence Corporation) and a digimatic indicator (manufactured by Mitutoyo Corporation), dried in an oven at 100 ° C. for 1 hour, and dried at 90 to 100 μm. Is obtained.

Next, a pattern P2 shown in FIG. 4 is overlaid on the pattern P1 in the same procedure as described above, and then printed and dried. Similarly, the pattern P shown in FIGS.
3 and P4 are sequentially printed on the patterns P1 and P2 and dried. 4 to 6, reference numerals h2 to h4 indicate blanks (holes).

Next, a double-sided tape is adhered to the X-ray absorbing film 14 formed by the patterns P1 to P4 with a lamination packer, thereby forming the adhesive layer 16 and the release paper 18 layer. 8 (PET film 12).
), And the chart seal S having the pattern shown in FIG. 9 is obtained.

On the chart seal S, a plurality of test charts 10 adhered to the common release paper 18 by the adhesive layer 16 are formed.

When the test chart is printed with an ink using a binder composed of a UV-curable resin as shown in Table 1, a UV screen X-ray blocking ink having the composition shown in Table 1 is kneaded, and the first test is carried out. The pattern P1 to the pattern P4 are superimposed and printed under the same conditions as in the example of the embodiment, and each pattern is printed and cured by irradiating ultraviolet rays with a 120 W metal halide lamp, and finally the same as shown in FIGS. 8 and 9 To obtain a chart seal S having the following pattern.

Using the test chart 10 in the first example of the above embodiment, as shown in FIG.
X-rays were taken under the conditions of KV, 5 mA and 80 KV, 8 mA. In FIG. 10, reference numeral 24 denotes an X-ray generator, 26 denotes an X-ray beam, 28 denotes a bed, and 30 denotes an X-ray film.

The test charts 10B and 10C were also attached to positions on the upper surface of the bed 28 where the patient 22 was covered and where the X-ray beam 26 did not cover the patient 22.

As a result of X-ray photography and development under the above conditions, the result is as shown in FIG.
When the degree of blackening of the portion corresponding to the test chart 10 was measured with a two-wavelength scanning densitometer,
Under the condition of 80 KV and 8 mA, the condition of KV and 5 mA is better.
Under the condition that the degree of blackening of the X-ray film 30 is high and 80 KV and 8 mA, the divided area 20A in the test chart 10
Each concentration step of ~ 20D could be read, but 40
Under the conditions of KV and 5 mA, the degree of blackening was not more than the detection limit value in the divided areas 20C and 20D, and the density level could not be determined.

In the first example of the above embodiment, the test chart 10 is provided with a plurality of divided areas 20A to 20D. However, the present invention is not limited to this. For example, FIG. Are omitted in the drawing), and as in the second example of the embodiment of the present invention shown in FIG.
A ring-shaped test chart 32 having a uniform linear absorption coefficient may be provided, and the direction may be determined by attaching a plurality of these to the subject.

Next, the manufacturing process of the test chart 32 for X-ray photography and correction according to the second example of this embodiment will be described. For example, a predetermined X shown in Table 1
The silk screen plate adjusted to a resist thickness of 100 μm in the pattern shown in FIG.
On the treated surface of the transparent easy-adhesion PET film 12 having a thickness of 0 μm, a film thickness of 110 μm is printed.

This is dried in an oven at 100 ° C. for 1 hour to obtain an X-ray absorbing film 34 having a thickness of 90 to 100 μm and having the pattern shown in FIG. The same applies to the case where the X-ray blocking inks indicated by and in Table 1 are used.

A double-sided tape is adhered to the coating surface of the X-ray absorbing film 34 with a lamination packer to form an adhesive layer 16.
Then, a layer of release paper 18 is formed, and punching is performed in the pattern shown in FIG. 7 to obtain the chart seal S2 shown in FIGS.

The test chart 32 was attached to the nasal crown of the patient 22 having a nose bone fracture in the same manner as described above, and X-ray photography was performed under the same conditions as described above. At 40 KV and 5 mA, soft tissue was observed. The chart pattern was also clearly photographed.

Under the conditions of 80 KV and 8 mA, only the bone tissue was observed and the chart pattern was photographed thinly. Also, with the naked eye alone, the chart pattern of the test chart of the X-ray blocking inks and the X-ray blocking inks in Table 1 showed a high density, but the chart photographing state due to the difference in the tube conditions was It was the same tendency.

Next, the evaluation / correction process when X-ray photography is performed using the test chart 10 will be described.

As shown in FIG. 10, a test chart 10 is provided on the X-ray tube side of the head of the patient 22 and on the opposite side of the head 22A along the bed 28 in the region of the X-ray beam 26. , 10B, and 10C are attached, and imaging is performed at 80 KV and 8 mA in an X-ray tube.

As shown in FIG. 11, the developed film 30 has a chart pattern 36A on the tube side.
The chart pattern 36B on the bed 28 is slightly smaller.

At this time, if the depth of the observed body tissue is estimated, the accurate horizontal size of the tissue and the distance (position) from the chart pattern on the film can be evaluated and corrected.

As a control, X-ray was applied to the patient 22.
When the test chart 10C is attached to a position that does not pass through, the chart stage and the calibration curve of the absorption amount of X-rays are created in advance in the example of the first embodiment, so that the patient 22 and a part of the tissue thereof can be analyzed. For a tissue whose X-ray absorption amount or absorption amount is known, the size in the depth direction can be estimated.

In each of the above embodiments, a test chart is formed by printing a pattern with an ink containing fine metal powder, but the present invention is not limited to this. Any test chart may be used as long as the film thickness is adjusted so that the X-ray absorption coefficient varies stepwise.

Therefore, for example, a photoresist is finely printed on a metal plate having a high X-ray absorption coefficient in a pattern in which the photographing direction and size can be specified, and the pattern is subjected to etching strength, etching time, And the number of times, the X-ray absorption coefficients of the divided regions in the pattern may be changed stepwise.

As will be described below, the thickness of each X-ray absorbing film is equal, and the X-ray absorption coefficient is adjusted by changing the kind and content of the metal contained, so that the entire test chart is uniform. It may be made to be the thickness of.

Hereinafter, a third embodiment of the present invention will be described in detail with reference to the drawings.

The test chart 40 for X-ray imaging evaluation and correction according to the third embodiment of the present invention shown in FIGS. 14 to 16 does not absorb X-rays or has a low X-ray absorption coefficient. For example, when the transparent easy-adhesion PET film 42 is used as a substrate sheet and its treated surface contains a metal having a high X-ray absorption coefficient, the X-ray absorption coefficient is set to a predetermined standard according to the type and content of the metal, and is large. The X-ray absorbing film 44 having a pattern in which the direction and the imaging direction are specified is formed in a uniform thickness,
Further, an adhesive layer 46 is formed so that the outside thereof can be adhered to the skin of a subject (for example, a human body), and the adhesive layer 46 is further covered with a release paper 48.

The X-ray absorption film 44 has a ring shape in plan view and four divided regions 50A having a central angle of 90 °.
Ｄ50D.

Each of the divided regions 50A to 50D is laminated by selecting two types from among four types of films so that the total film thickness becomes equal, so that the X-ray absorption coefficient gradually becomes four gradations. Has been.

Further, inside the ring-shaped X-ray absorbing film 44, a small circular transmission region 50E composed of the adhesive layer 46 and the PET film 42 is formed, whereby the test chart 40 has five gradations as a whole. Further, an outer peripheral region 50F having the same film structure as the divided region 50D having the highest X-ray absorption coefficient is formed in a ring shape on the outer periphery.

The metal having a high X-ray absorption coefficient contained in the X-ray absorption film 44 is lead, bismuth, barium, tungsten, a compound thereof or a mixture thereof.
In any case, a powdery material is mixed with a binder and printed as a pattern on the PET film 42 as an X-ray blocking ink.

Alternatively, the metal powder is mixed with a binder made of a photocurable resin to form an X-ray blocking ink, and after the pattern is printed, light is irradiated from a curing light source to cure the pattern.

The binder is made of at least one resin selected from the group consisting of acrylic, urethane, vinyl chloride, and polyester. The photo-curable resin as the binder is, for example, urethane acrylate, polyester acrylate or a mixture thereof which is cured by ultraviolet rays.

The above-mentioned metal powder, binder, solvent and P / V ratio are, for example, as shown in Table 2 below.

[0071]

[Table 2]

Next, a method of manufacturing the test chart 40 will be described.

First, the X-ray blocking ink shown in Table 2 is kneaded and formed with three rolls from the screen printing ink SS.

Next, the pattern P shown in FIG.
a, a silk screen plate (Tetron 150 mesh, manufactured by Mino Group) 52A having a resist thickness of 65 μm, and a 100 μm thick transparent easy-adhesion PET film (manufactured by Toray Industries, Inc.) 42 Print to film thickness. Reference numeral H1 in FIG. 17A indicates a blank portion where ink is not transferred.

The film thickness and the state of the coating film were confirmed with a laser focus displacement meter (manufactured by Keyence Corporation) and a digimatic indicator (manufactured by Mitutoyo Corporation), and dried in an oven at 100 ° C. for 1 hour. In A), a pattern P11 having a thickness of 55 to 65 μ as shown by the oblique line on the upper right is obtained.

Next, on the pattern P11 of the coating film, the X-ray blocking ink in Table 2 was applied by the silk screen plate 52B of the pattern Pb shown in FIG. 17B, as shown in FIG. 20B. The same dotted line pattern P12 is printed and dried in the same procedure as above, and the whole is 55-55.
A pattern with a uniform film thickness of 65 μm (see FIG. 20B)
Get.

At the time of this silk screen printing, the inner peripheral surface of the pattern P11 regulates the outer peripheral surface of the pattern P12, and acts as a mold. Even when the thick silk screen printing is performed, the patterns P11 and P12 can be formed to have a uniform thickness without unevenness on the surface.

Next, the X-ray blocking ink in Table 2 was applied onto the flat patterns P11 and P12 shown in FIG. 20B by the silk screen plate 52C of the pattern Pc shown in FIG. 18C. In the pattern P13 indicated by oblique lines falling rightward in FIG. 20 (C), the same procedure as described above is performed with the same thickness, printed and dried, and 110-130 μm in the overlapping portion with the patterns P11 and P12, and in other portions. 55-65
A pattern having a total film thickness of μm (see FIG. 20C) is obtained.
The blank portion H2 in the pattern Pc in FIG. 18C indicates a blank portion where ink is not transferred.

Next, the patterns P11, P12, P1
3, the X-ray blocking ink in Table 2 was applied to the silk screen plate 52D of the pattern Pd shown in FIG. Of printing, thickness and printing
After drying, the pattern shown in FIG.

This silk screen printing is performed according to FIG.
As in the case of the silk screen plate 52B of (B), the X-ray blocking ink is pressed in such a manner that the coating film in the patterns P11, P12, and P13 is embedded in only one layer. Therefore, the surface of the pattern in FIG. 20D has a uniform thickness except for the central portion.

Next, a double-sided tape is adhered to the X-ray absorbing film 44 formed by the above-mentioned procedure with a lamination packer, thereby forming a layer of an adhesive layer 46 and a release paper 48. Finally, FIG. A punching process is performed using the pattern Pe shown in FIG.
5. As a whole, a chart seal S having a pattern shown in FIG. 21 (without the PET film 42) and FIG.
Get 3.

A plurality of test charts 40 attached to the common release paper 48 by the adhesive layer 46 are formed on the chart seal S3.

The test chart 40 obtained above was spotted on the nasal head of a patient with a broken nose bone, and X-rays were taken. Under X-ray tube conditions of 40 KV and 5 mA, soft tissues were observed and the chart pattern was changed. It is clearly photographed in 4 gradations,
At 80 KV and 8 mA, only the bone tissue was observed and the chart pattern was photographed slightly thinner, but the tendency was the same.

When the test chart is printed with an ink using a binder made of a UV-curable resin, a UV screen X-ray blocking ink is kneaded, and the patterns Pa to Pd are formed under the same conditions as in the above embodiment. , And cured by irradiating ultraviolet rays with a 120 W metal halide lamp for each pattern printing to finally obtain a chart seal S3 having a pattern similar to that shown in FIGS. 21 and 22.

Further, the test chart, the manufacturing method thereof, and the imaging evaluation / correction method in each of the above embodiments are all for X-ray imaging, but the present invention is not limited thereto. The same applies to the case of gamma rays having ionizing radiation as well as X-rays.

The test chart 40 was applied on the discolored surface of a gamma indicator / 2-10 kGy (manufactured by Etchham Co., Ltd.) and irradiated with 10 kGy γ-rays.
Was removed, color change of four gradations was confirmed in the same manner as described above.

[0087]

Since the present invention is constructed as described above, the size, direction and ionizing radiation absorption stage during and after imaging can be specified on the same screen as the subject at the time of ionizing radiation imaging. It has an excellent effect that evaluation and correction of ionizing radiation imaging can be performed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first example of an embodiment of an X-ray imaging evaluation / correction test chart according to the present invention.

FIG. 2 is an enlarged sectional view taken along the line II-II of FIG.

FIG. 3 is a plan view showing a pattern when a test chart is overprinted.

FIG. 4 is a plan view showing a pattern when a test chart is overprinted.

FIG. 5 is a plan view showing a pattern when a test chart is overprinted.

FIG. 6 is a plan view showing a pattern when a test chart is overprinted.

FIG. 7 is a plan view showing a punch used in a test chart forming process.

FIG. 8 is a plan view showing a completed chart seal.

FIG. 9 is a side view of the same.

FIG. 10 is a schematic front view showing a form in which a patient is X-rayed using the test chart.

FIG. 11 is a developed film obtained by radiographing the patient.

FIG. 12 is a plan view showing a chart seal according to a second example of the embodiment of the present invention.

FIG. 13 is a side view of the same.

FIG. 14 is a plan view showing a third embodiment of the X-ray imaging evaluation / correction test chart according to the present invention;

15 is an enlarged sectional view taken along line XV-XV in FIG.

16 is an enlarged sectional view taken along line XVI-XVI in FIG.

FIG. 17 is a plan view showing first and second printing silk screens when a test chart is overprinted.

FIG. 18 is a plan view showing third and fourth printing silk screens when the test chart is overprinted.

FIG. 19 is a plan view showing a cutting die used in a test chart forming process.

FIG. 20 is a plan view showing a printing pattern in the process of overprinting the test chart.

FIG. 21 is a plan view showing a completed chart seal.

FIG. 22 is a side view of the same.

[Explanation of symbols]

 10, 32, 40: Test chart 12, 42: PET film 14, 34, 44: X-ray absorbing film 16, 46: Adhesive layer 18, 48: Release paper 20A to 20D, 50A to 50D: Divided area 20E, 50E Transmission area 22 Patient 22A Head 24 X-ray generator 26 X-ray beam 28 Bed 30 X-ray film 36A, 36B Chart pattern 50F Peripheral area 52A-50D Silk screen P11-P14, Pa, Pb, Pc, Pd ... pattern

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masanao Watanabe 1-1-1 Ichigaya Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd.

Claims (18)

[Claims] The present invention relates to a sheet which does not absorb ionizing radiation or has a low ionizing radiation absorption coefficient, by adjusting at least one of an ionizing radiation absorption coefficient, a content and a film thickness of a metal contained therein. 9 is a test chart for evaluating and correcting ionizing radiation imaging in which an ionizing radiation absorbing film is formed in a pattern in which a radiation absorption coefficient has a predetermined standard and a size and an imaging direction can be specified. 2. A test chart according to claim 1, wherein said ionizing radiation absorbing film is formed by laminating a plurality of coating films having different patterns. 3. The ionizing radiation absorbing film according to claim 1, wherein the ionizing radiation absorbing film is divided into a plurality of regions, and each divided region is formed of a coating film having a different ionizing radiation absorption coefficient. Test chart for evaluation and correction of ionizing radiation imaging. 4. The ionizing radiation absorbing film according to claim 1, 2 or 3, wherein the ionizing radiation absorbing film is formed in a ring shape, and the ring is divided into a plurality of regions in a circumferential direction, and each region has a different ionizing radiation absorbing film. A test chart for evaluating and correcting ionizing radiation imaging, wherein the test chart is a coefficient. 5. An ionizing radiation imaging evaluation according to claim 1, wherein an outer peripheral region having a higher ionizing radiation absorption coefficient than an inner region is formed along the outer peripheral edge of the pattern. -Correction test chart. 6. A test chart for evaluating and correcting ionizing radiation according to claim 1, wherein the total thickness of the ionizing radiation absorbing film is substantially equal over the entire surface. 7. An ionizing radiation imaging evaluation / correction method according to claim 1, wherein a different ionizing radiation absorption coefficient is obtained by making the thickness of the ionizing radiation absorbing film different for each different region. Test chart. 8. An ionizing radiation imaging evaluation / correction test chart according to claim 1, wherein an adhesive layer for attaching a sheet to an object is formed by covering the ionizing radiation absorbing film. . 9. An ink formed by kneading a metal powder having a high absorption coefficient of ionizing radiation with a binder, does not absorb ionizing radiation, or has a size and an image when attached to a subject on a sheet having a low absorption coefficient. A method for producing a test chart for ionizing radiation imaging evaluation and correction, characterized by printing an ionizing radiation absorbing film in a pattern whose direction can be specified. 10. An ionizing radiation imaging evaluation / correction according to claim 9, wherein the printing of the ionizing radiation absorbing film does not absorb ionizing radiation or forms a region having a relatively low absorption coefficient. Method of manufacturing test charts. 11. The metal powder according to claim 9, wherein the metal powder is made of at least one of lead, bismuth, barium, tungsten, each compound, and a mixture thereof. At least one of vinyl chloride, vinyl acetate, and polyester
A method for producing a test chart for evaluating and correcting ionizing radiation imaging, characterized by comprising two resins. 12. The method according to claim 9, wherein
The metal powder is composed of at least one of lead, bismuth, barium, tungsten, each compound, and a mixture thereof, and the binder is composed of a photocurable resin. Irradiate,
A method for producing a test chart for evaluating / correcting ionizing radiation, wherein the pattern is cured. 13. The method according to claim 9, wherein
The ionizing radiation absorption coefficient of the ionizing radiation absorbing film is adjusted by changing at least one of the type of the metal powder, the ink P / V ratio, and the printed film thickness. Manufacturing method of test chart for correction. 14. The method according to claim 9, wherein
The ionizing radiation absorbing film is formed by sequentially printing a plurality of thin films having different patterns, forming the thin film from a plurality of regions having the same number of layers of different thin films, and having a different ionizing radiation absorption coefficient for each region, and A method for producing a test chart for evaluating and correcting ionizing radiation, wherein the total thickness is made equal. 15. The method according to claim 9, wherein
The ionizing radiation absorbing film, a plurality of thin films of different patterns are sequentially superimposed and printed, formed from a plurality of regions having a different number of thin films stacked, the ionizing radiation absorption coefficient for each region is different. Of manufacturing test charts for evaluating and correcting ionizing radiation imaging. 16. On a metal plate having a high ionizing radiation absorption coefficient,
A photoresist is finely printed with a pattern that can specify the size and the direction of ionizing radiation when attached to a subject, and the thickness of the metal plate is divided into a plurality of regions by exposure and etching, and the pattern is divided into a plurality of regions. Forming an ionizing radiation absorbing film by adjusting the ionizing radiation absorption coefficient so as to obtain a different predetermined ionizing radiation absorption coefficient. 17. The method according to claim 9, wherein
After forming the ionizing radiation absorbing film, manufacturing a test chart for ionizing radiation imaging evaluation / correction, characterized by forming a layer of an adhesive capable of sticking to the subject by covering the ionizing radiation absorbing film. Method. 18. The method according to claim 18, wherein the ionizing radiation absorption coefficient, the content and the film thickness of a metal contained in the sheet are not adjusted or the ionizing radiation absorption coefficient is low. The radiation absorption coefficient is a predetermined standard, and a test chart formed by forming an ionizing radiation absorbing film in a pattern whose size and imaging direction are specified, the ionizing radiation source side portion of the subject in the ionizing radiation irradiation area and The size and image of the attached test chart based on the mass absorption coefficient and the ionizing radiation intensity distribution with respect to a fixed ionizing radiation source output inspected after irradiation with ionizing radiation on the bed on which the subject is mounted, Radiation imaging characterized by identifying the tissue and mass distribution in the subject, and the position and size of the affected area by evaluating the contrast ratio of the subject Value-correction method.