JPS6356960B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intensifying screen. More specifically, the present invention relates to an intensifying screen for chest X-ray photography.

As is well known, intensifying screens are used for medical diagnosis.
X-ray photographic film (hereinafter referred to as ``film'') is used to improve the sensitivity of the imaging system in radiography in various fields such as medical radiography such as X-ray photography and industrial radiography for the purpose of non-destructive testing of materials. It is used in close contact with
Basically, it consists of a support such as paper or plastic and a phosphor layer provided on one side of the support. The phosphor layer is made by dispersing a phosphor that emits high-intensity light upon radiation excitation in a binder resin, and the surface of this phosphor layer (the surface opposite to the support side) is generally covered with a cellulose acetate membrane. , a transparent resin protective film such as a polymethacrylate film or a polyethylene terephthalate film. Further, some intensifying screens are provided with a light reflecting layer or a light absorbing layer between the support and the phosphor layer. When performing radiography, the film is held in a frame called a cassette in a state in which the film is tightly sandwiched between two intensifying screens having the above structure, and this frame is used.

Recently, when diagnosing chest diseases such as lung cancer using chest X-ray photographs, it has become increasingly necessary to diagnose not only the lung field but also the trachea and bronchi superimposed on the thoracic vertebrae and heart. However, conventional intensifying screens have uniform sensitivity within the same plane, and when exposed to X-rays under the same conditions, the amount of fluorescent light emitted from the surface of the phosphor layer is almost the same at any position. Film also has uniform sensitivity, so when using it to perform plain chest imaging or tomography, it is difficult to diagnose the lung field, trachea, and bronchi at the same time using a single X-ray photograph. It was hot. In other words, in addition to the lung fields, a chest X-ray photograph shows X-ray images of the trachea and bronchi superimposed on the thoracic vertebrae and heart, but since the transmittance of X-rays to each organ differs greatly, The degree of darkening in the photograph increases in the order of the lung fields, and the density range of the X-ray photograph covers a fairly wide range. Therefore, if images are taken under X-ray exposure conditions that provide an appropriate degree of photographic darkening that is good for lung field diagnosis, the degree of photographic darkening of these organs will be lower due to X-ray absorption in the thoracic vertebrae and heart. As a result, the shadows of the trachea and bronchi superimposed on these organs cannot be seen, making it impossible to diagnose them.On the other hand, when images are taken under X-ray exposure conditions appropriate for diagnosing the trachea and bronchi, the lung fields appear black in the photograph. It becomes too much,
Diagnosis of the lung fields becomes impossible.

From the above points, conventionally, multiple X-ray photographs were taken under optimal X-ray exposure conditions for the lung field, trachea, and bronchi, respectively, in order to obtain photographs with the appropriate degree of darkening for each of the lung fields, trachea, and bronchi. Chest X-rays were used to diagnose the patient's chest by taking pictures of the patient's chest, or by using bronchography using a contrast agent. However, taking multiple X-rays is undesirable because it increases the patient's radiation exposure, and bronchography contrast X-rays are painful for the patient, and simple radiographs are undesirable. The problem was that it required several times more time and expense.

The present invention was made in view of the above-mentioned situation in chest X-ray photography, and allows the trachea and bronchi that are superimposed on the lung field, thoracic vertebrae, or heart to be visualized on a single film in a single X-ray image. Chest X obtained with each image having an appropriate degree of photographic darkening
The object of the present invention is to provide an intensifying screen for line photography.

One of the intensifying screens for chest X-ray photography of the present invention is
In an intensifying screen consisting of a support and a phosphor layer provided on the support, when the same dose of X-rays is incident on the entire surface of the phosphor layer, the support of the phosphor layer thoracic vertebrae, which is formed so that the amount of light emitted from the surface opposite to the intensifying screen is greater in a band-shaped part extending from the center of one end of the intensifying screen to the center of the opposite end than in other parts. It is characterized by having a superimposed trachea and a band-shaped high-sensitivity part for trachea sensitization, so that a readable lung field image and a trachea and bronchus image superimposed on the thoracic vertebrae can be projected on the same X-ray film.

Another aspect of the intensifying screen for chest X-ray photography of the present invention is an intensifying screen consisting of a support and a phosphor layer provided on the support. When the same dose of X-rays is incident on the phosphor layer, the amount of light emitted from the surface of the phosphor layer opposite to the support is directed from the center of one end of the intensifying screen to the center of the opposite end. A tracheal augment that overlaps the thoracic vertebrae and is formed so that the number of tracheal extensions overlaps the thoracic vertebrae, and is formed so that the number of tracheal extensions overlaps the thoracic vertebrae. It has a band-like high-sensitivity area for sensitization, a high-sensitivity area for bronchial sensitization that overlaps the trachea and bronchi, and the heart, which overlaps the thoracic vertebrae, and a lung field that can be interpreted on the same X-ray film, and a trachea that overlaps the thoracic vertebrae. It is also characterized by being able to project a bronchial image and a bronchial image superimposed on the heart.

Furthermore, the intensifying screen for chest X-ray photography of the present invention includes:
The above-mentioned two intensifying screens of the present invention are combined to make it possible to project on the same X-ray film a readable lung field image, trachea and bronchial images superimposed on the thoracic vertebrae, and bronchial images superimposed on the heart. Features.

If the intensifying screen of the present invention is used to perform simple chest X-ray photography or tomography, the photographic sensitivity of the thoracic vertebrae and heart, which have higher X-ray absorption than the lung field, can be partially increased, resulting in a single image. It becomes possible to simultaneously diagnose the lung field, the thoracic vertebrae, or the trachea and bronchi superimposed on the heart from the X-ray photograph.

The present invention will be explained in detail below.

FIG. 1 shows a schematic diagram of an adult's chest X-ray photograph taken by plain radiography. Upper center part of the photo 1
1, the trachea that overlaps the thoracic vertebrae is located almost in the center 12
shows the trachea and bronchi that overlap the thoracic vertebrae, the right central portion 13 shows the bronchus that overlaps the heart, and the left and right portions 14 show the lung fields. When imaging is performed using a conventional intensifying screen under X-ray exposure conditions that provide a degree of photographic darkening suitable for lung field diagnosis,
The degree of darkening in photographs of the trachea and bronchi that overlap the thoracic vertebrae and the bronchi that overlap the heart becomes extremely low, and the shadows of the trachea and bronchi become extremely unclear, making it impossible to diagnose them. Therefore, in the intensifying screen for chest X-ray photography of the present invention, the sensitivity of the thoracic vertebrae with high X-ray absorption that overlaps with the trachea and bronchi, or the part where the heart is projected, is lower than that of the other parts (the part where the lung fields are projected). ) is provided.

FIG. 2 shows a pattern of sensitivity distribution in the first intensifying screen of the present invention. As shown in FIG. 2, a band-shaped portion 21 in which X-ray images of the thoracic vertebrae, trachea, and bronchi are superimposed and projected from the center of one end of the intensifying screen to the center of the opposite end is the lung field. X
It is designed to have higher sensitivity than other parts 22 including the part on which the line image is projected (hereinafter, "other parts 22" will be referred to as "high-sensitivity parts 21" for convenience).
(referred to as "low sensitivity portion 22"). The width a of this band-like high-sensitivity portion 21 is preferably about 45 mm based on the average value of a large number of chest clinical X-ray photographs.

FIG. 3 shows a pattern of sensitivity distribution in the second intensifying screen of the present invention. As shown in FIG. 3, a band-shaped portion 311 extends from the center of one end of the intensifying screen to the center of the opposite end, and onto which X-ray images of the thoracic vertebrae and trachea are projected in a superimposed manner.
Then, continuous to this band-shaped portion 311, the band-shaped portion 3
A portion 31 that extends in a nearly triangular shape from one end of the thoracic vertebrae to the other end and includes a portion 312 on which X-ray images of the thoracic vertebrae, trachea and bronchi, and the heart and bronchi are projected in a superimposed manner is an X-ray image of the lung field. It is designed to have higher sensitivity than other parts 32 including the part on which the image is projected (hereinafter, for convenience, "other parts 32" will be referred to as "low sensitivity parts 32" with respect to "high sensitivity parts 31"). ). Almost the X-ray images of the thoracic vertebrae and trachea are projected within the band-shaped high-sensitivity portion 311, and the X-ray images of the lung field are
To prevent line images from being projected here,
From the average value of a large number of chest clinical X-ray photographs, the width a
is about 45 mm, and the length b is preferably about 90 mm, for example, in the case of a large-angle (35 cm x 35 cm) intensifying screen commonly used for chest X-ray photography. Similarly, the X-ray images of the thoracic vertebrae, heart, trachea, and bronchi are projected within the high-sensitivity portion 312 that spreads in a triangular shape, and in order to prevent the X-ray images of the lung field from being projected here, it is necessary to Since the heart is located at a position slightly to the right of the center of the human body, the boundary line between the high-sensitivity part 312 and the low-sensitivity part 32, and the extension line of the boundary line between the band-shaped high-sensitivity part 311 and the low-sensitivity part 32. Preferably, the angles θ ₁ and θ ₂ are about 7.5° and about 20.5°, respectively, or, quite conversely, about 20.5° and about 7.5°, respectively.

When performing chest X-ray photography using the intensifying screen of the present invention, either a plurality of the first intensifying screens described above are used (two in the case of plain imaging, generally three in the case of tomography). (10 to 10 images), or use the above-mentioned second intensifying screen by stacking multiple sheets (for simple photography, use 2
(generally 3 to 10 images for tomography), or one or more of the first intensifying screens and one or more of the second intensifying screens (for simple imaging, one of each In the case of tomography, one of the images is one or more, and the other is two or more,
The total number of sheets is generally 3 to 10). In order to reduce the difference between the photographic darkening degree of the lung field and the photographic darkening degree of the trachea and bronchi in the obtained X-ray photograph, the sensitivity distribution of the multiple superimposed intensifying screens as a whole is as follows. is desirable. In other words, when using a combination of first intensifying screens or a combination of second intensifying screens, the overall sensitivity is divided into two levels, but the low sensitivity part (low sensitivity in Figure 2) When the sensitivity of the sensitive part 22 or the part corresponding to the low-sensitivity part 32 in Fig. 3 is set to 1.0,
It is desirable that the sensitivity of the highly sensitive portion (corresponding to the high-sensitivity portion 21 in FIG. 2 or the high-sensitivity portion 31 in FIG. 3) be 1.8 or more, preferably 2.2 or more. Furthermore, when the first intensifying screen and the second intensifying screen are used in combination, the overall sensitivity is divided into three stages, and the lowest sensitivity part (corresponding to the low sensitivity part 32 in Figure 3) part) sensitivity
When set to 1.0, the sensitivity of the intermediate sensitivity part (the part corresponding to two triangles with apex angles θ ₁ and θ ₂ obtained by removing the high sensitivity part 21 in Figure 2 from the high sensitivity part 31 in Figure 3) is 1.5 to 2.2, and the sensitivity of the part with the highest sensitivity (corresponding to the high-sensitivity part 21 in Figure 2) is 1.8 or more, preferably 2.2.
It is desirable that the above is achieved.

As mentioned above, using the intensifying screen of the present invention,
When performing line photography, a combination of first intensifying screens, a combination of second intensifying screens, and a first intensifying screen are used.
One of the combinations of an intensifying screen and a second intensifying screen is used, but since the sensitivity is divided into three levels, it is preferable to use a combination of the first intensifying screen and the second intensifying screen. is particularly preferred.

The high-sensitivity areas of the intensifying screen of the present invention can be formed by various methods, one of which is to form the phosphor layer in the shaded area in Figure 2 or the shaded area in Figure 3 by forming the phosphor layer in other areas. There is a method of making the high-sensitivity portion 21 or 31 thicker than the layer. The high-sensitivity portion 21 or 31 having a thicker phosphor layer than the low-sensitivity portion 22 or 32 can be formed, for example, by the following method. That is, the phosphor layer of the intensifying screen is prepared by dispersing an X-ray phosphor in a binder resin to prepare a phosphor coating solution, and coating the obtained phosphor coating solution on a support and drying it. However, when applying the phosphor coating liquid onto the support, a thin metal plate (spacer) whose center part is thicker than both ends is placed on both sides of the support. The fluorescent coating solution is applied onto the support using a doctor blade using the spacer as a guide. In this case, by setting spacers with the same length in the thick center part on both sides of the support and applying them, the phosphor layer in the band-shaped high-sensitivity area 21 will be the same as the phosphor layer in the low-sensitivity area 22. The first intensifying screen of the present invention, as shown in FIG. When applied, a high-sensitivity area 3 consisting of a band-shaped high-sensitivity area 311 and a triangular-shaped high-sensitivity area 312 is formed.
A second intensifying screen of the invention is obtained, as shown in FIG. After forming a phosphor layer having different thicknesses in the high-sensitivity portion 21 or 31 and the low-sensitivity portion 22 or 32 as described above, the surface of the phosphor layer (the surface opposite to the support side) is A transparent resin protective film is provided on the film to obtain an intensifying screen of the present invention.

In addition to the above, first, a phosphor coating solution is uniformly applied onto the support using a roll coater, a knife coater, etc., and then heated and dried to form a phosphor layer with a uniform thickness. Place a mask with the pattern shown in the shaded area or the shaded area in Figure 3 punched out on the phosphor layer so that the punched out part is in a predetermined position, and apply the phosphor coating liquid to the punched out part using a doctor blade. The film is coated and dried by heating to form a high-sensitivity region 21 or 31 in which the phosphor layer is thicker than the low-sensitivity region 22 or 32, and then a transparent resin protective film is provided on the surface of the phosphor layer. Inventive intensifying screens may also be manufactured.

Furthermore, a transparent resin protective film is first formed on a smooth substrate, then a phosphor layer with different thickness depending on the location is formed thereon in the same manner as described above, and then the phosphor layer is The intensifying screen of the present invention may be manufactured by peeling the film together with the transparent resin protective film from the substrate and heat-pressing it onto a support coated with an adhesive on one side.

In addition, the intensifying screen of the present invention, instead of changing the thickness of the phosphor layer to form a high-sensitivity area of a specific pattern as described above, A light absorbing layer made of a coloring agent having a body color such as black, blue, or red is formed in the area or the area other than the shaded area in Figure 3 to reduce the amount of fluorescent light emitted from the phosphor layer in this area. Alternatively, a light reflecting layer made of a white pigment or the like may be formed in the shaded area in FIG. 2 or the shaded area in FIG. 3 between the support and the phosphor layer. The high-sensitivity portion 21 or 31 may be formed by increasing the amount of fluorescent light emitted from the phosphor layer of the portion. Alternatively, the intensifying screen may have a sensitivity distribution by forming a phosphor layer using X-ray phosphors having different luminances.

In addition, in the intensifying screen of the present invention, the boundary part between the high-sensitivity part and the low-sensitivity part (21 and 22 in FIG.
(and the boundary between 31 and 32 in Figure 3) do not have a sharp drop in sensitivity, but instead have a gentle sensitivity gradient so that the sensitivity changes gradually. This is preferable because no natural border line appears and it does not interfere with image interpretation.

The various materials used in the intensifying screen of the present invention are the same as those used in conventional intensifying screens. That is, the X-ray fluorophores include _CaWO4 fluorophore, _BaSO4 :Ph fluorophore, and ZnS:
Ag phosphor, Y ₂ O ₂ S:Tb phosphor, Gd ₂ O ₂ S:Tb phosphor, BaFCl:Eu phosphor, etc. are used. As the binder resin, nitrified cotton, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, etc. are used. Further, as the transparent resin protective film, a thin film of cellulose acetate, polymethacrylate, etc. is used. Furthermore, processed paper, plastic sheets, etc. are used as the support. It is particularly preferred that the support has a large square size (35 cm x 35 cm), which is the size of an intensifying screen commonly used for chest X-ray photography.

If chest X-ray photography is performed using the first intensifying screen of the present invention in combination, the difference in the degree of darkening between the lung field and the thoracic vertebrae in the obtained X-ray photograph will be reduced, and as a result, the shadows in the lung field will be reduced. In addition, shadows of the trachea and bronchi superimposed on the thoracic vertebrae become clearly visible. In addition, if chest X-ray photography is performed by combining the second intensifying screen of the present invention or by combining the first intensifying screen and the second intensifying screen of the present invention, an X-ray photograph obtained The difference in the degree of darkening in the photographs of the lung field, heart, and thoracic vertebrae has become smaller, and as a result, in addition to the shadows in the lung fields, the shadows of the bronchi superimposed on the heart and the trachea and bronchi superimposed on the thoracic vertebrae can now be seen clearly. Become.

As explained above, if the intensifying screen for chest X-ray photography of the present invention is used, X-ray images of the lung field and thoracic vertebrae, which have significantly different X-ray absorption, or of the lung field, heart, and thoracic vertebrae can be obtained in a single X-ray photograph. Since the images can be obtained even with a small difference in the degree of darkening, it becomes possible to diagnose the lung field, trachea, and bronchi at the same time using one film.

Next, the present invention will be explained with reference to Examples.

Example 1 A portion of a 0.4 mm thick large square size high-quality paper (supporting material) corresponding to 22 in Figure 2 was coated with methyl orange, leaving a 45 mm wide strip portion corresponding to 21 (shaded area) in Figure 2. It was then dyed. This staining is carried out using methyl orange dissolved in water as shown in Figure 2 on high-quality paper.
This was done by applying it to the corresponding area and drying it. In this case, the degree of coloring at the boundary part is adjusted to the inside of the part corresponding to 21 in Fig. 2 so that the border part between the part corresponding to 22 in Fig. 2 and the part corresponding to 21 in Fig. 2 does not stand out. The dyeing was carried out so that the direction gradually decreases. Next, CaWO ₄ phosphor was mixed and dispersed in a solution of nitrified cotton dissolved in a mixed solvent of butyl acetate, ethyl acetate, and acetone at a ratio of 8 parts by weight to 1 part by weight of nitrified cotton. The phosphor coating liquid was uniformly applied to the entire surface of the high-quality paper dyed with methyl orange using a roll coater and dried to form a phosphor layer having a phosphor coating weight of 40 mg/cm ² . Next, an acetone solution of cellulose acetate was uniformly applied onto this phosphor layer and dried to form a cellulose acetate film (transparent resin protective film) with a film thickness of about 10 μm. An intensifying screen was thus obtained.

Separately, place a portion of 0.4 mm thick large-sized high-quality paper (supporting material) corresponding to 32 in Figure 3 into a third
The area corresponding to 31 (hatched area) in the figure was left and stained with methyl orange in the same manner as described above. A, b, θ ₁ and θ ₂ of the portion corresponding to 31 in FIG. 3 were set to a=45 mm, b=90 mm, θ ₁ =7.5° and θ ₂ =20.5°, respectively. In addition, so that the boundary between the portion corresponding to 32 in FIG. 3 and the portion corresponding to 31 in FIG. Once colored to become progressively lower. An intensifying screen was obtained in the same manner as the above intensifying screen except that high-quality paper dyed with methyl orange was used.

The film was sandwiched between the intensifying screens obtained as described above, placed in a cassette, and the tube voltage
When we examined the sensitivity distribution by irradiating 80KVp X-rays, we found that the lowest sensitivity area (corresponding to 32 in Figure 3) was compared to the intermediate sensitivity area (from 31 in Figure 3 to 21 in Figure 2). The area corresponding to the two triangles whose apex angles are θ ₁ and θ ₂ ) is approximately 1.5 times as sensitive, and the area with the highest sensitivity (the area corresponding to 21 in Figure 2)
showed approximately 2.2 times the sensitivity.

Next, use the front intensifying screen (the intensifying screen placed on the side of the X-ray source with respect to the film), and the intensifying screen with the rear intensifying screen (the side opposite the X-ray source with respect to the film). When chest X-ray photography was performed by placing the cassette on the abdominal side and irradiating X-rays with a tube voltage of 80 KVp from the dorsal side, the trachea was superimposed on the lung field and thoracic vertebrae. The shadows of the bronchi and the bronchus superimposed on the heart were clearly imaged on the same film, making it possible to diagnose the lung field, trachea, and bronchi at the same time.

Example 2 The same phosphor coating solution as in Example 1 was uniformly applied using a knife coater onto the light absorbing layer of a large square size polyethylene terephthalate sheet (support) having a thickness of about 250 μm and having a carbon black light absorbing layer. and dried to form a phosphor layer with a phosphor coating weight of 30 mg/cm ² . Next, the area other than the strip-shaped part of width a 45 mm corresponding to 21 in FIG. 2 on this phosphor layer (that is, the area corresponding to 22 in FIG. 2) is masked, and the area corresponding to 21 in FIG. 2 is masked. Apply the same phosphor coating solution as above evenly to the corresponding strip using a doctor blade and dry it until the phosphor coating weight is 50%.
A phosphor layer of mg/cm ² was formed. Next, in the same manner as in Example 1, a cellulose acetate film (transparent resin protective film) having a thickness of about 10 μm was formed on the phosphor layer formed as described above, the thickness of which varied depending on the location. An intensifying screen was thus obtained. This intensifying screen 2
I created one.

The film was sandwiched between the two intensifying screens obtained as described above, placed in a cassette, and the tube voltage
When we examined the sensitivity distribution by irradiating 80KVp X-rays, we found that the area with high sensitivity (the area corresponding to 21 in Figure 2) is approximately It showed 2.2 times more sensitivity.

Next, a chest X-ray was taken using two intensifying screens and a cassette placed on the abdominal side and irradiated with X-rays at a tube voltage of 80 KVp from the dorsal side. The shadows of the bronchus and bronchus were clearly imaged on the same film, making it possible to diagnose the lung field, trachea, and bronchi at the same time.

Example 3 Using a knife coater, the same phosphor coating solution as in Example 1 was uniformly applied onto the light absorbing layer of a large size polyethylene terephthalate sheet (support) having a thickness of about 250 μm having a carbon black light absorbing layer.
It was dried to form a phosphor layer with a phosphor coating weight of 30 mg/cm ² . Next, 3 in Figure 3 on this phosphor layer.
3 in Fig. 3 by masking the part other than the part corresponding to 1 (that is, the part corresponding to 32 in Fig. 3).
The same phosphor coating solution as above was applied uniformly to the portion corresponding to No. 1 using a doctor blade and dried to form a phosphor layer having a phosphor coating weight of 50 mg/cm ² . At this time, a of the part corresponding to 31 in Fig. 3,
b, θ ₁ and θ ₂ are a=45mm, b=90mm, respectively.
θ ₁ =7.5° and θ ₂ =20.5°. Next, in the same manner as in Example 1, a cellulose acetate film (transparent resin protective film) having a thickness of about 10 μm was formed on the phosphor layer formed as described above, the thickness of which varied depending on the location.
An intensifying screen was thus obtained.

The film was sandwiched between the intensifying screen obtained as described above and the intensifying screen of Example 2, placed in a cassette, and irradiated with X-rays at a tube voltage of 80 KVp to examine the sensitivity distribution. The middle sensitivity part is about 1.7 times the lowest part, and the highest sensitivity part is about 2.2 times the lowest part.
It showed twice the sensitivity.

Next, using the intensifying screen as the front intensifying screen and the intensifying screen as the rear intensifying screen, the cassette was placed on the abdominal side and X-rays with a tube voltage of 80 KVp were irradiated from the dorsal side to take a chest X-ray photograph. After getting used to it, the shadows of the lung field, the trachea and bronchi superimposed on the thoracic vertebrae, and the shadows of the bronchus superimposed on the heart were clearly imaged on the same film, making it possible to diagnose the lung field, trachea, and bronchi at the same time.

[Brief explanation of drawings]

FIG. 1 shows a schematic diagram of a chest X-ray photograph. 11... Part where the trachea overlaps the thoracic vertebrae, 12... Part where the trachea and bronchi overlap with the thoracic vertebrae, 13... Part where the bronchus overlaps with the heart, 14... Lung field part. FIGS. 2 and 3 show patterns of sensitivity distribution in the intensifying screen of the present invention. 21, 32...High sensitivity part, 22, 32...Low sensitivity part.

Claims (1)

[Claims] 1. In an intensifying screen consisting of a support and a phosphor layer provided on the support, when the same dose of X-rays is incident on the entire surface of the phosphor layer, the phosphor The amount of light emitted from the surface of the light layer opposite to the support is greater in a band-shaped portion extending from the center of one end of the intensifying screen to the center of the opposite end than in other portions. In addition, a band-shaped high-sensitivity area for sensitizing the trachea and bronchus superimposed on the thoracic vertebrae was formed, making it possible to image legible lung field images and trachea and bronchus images superimposed on the thoracic vertebrae on the same X-ray film. Characteristic intensifying screen for chest X-ray photography. 2. In an intensifying screen consisting of a support and a phosphor layer provided on the support, when the same dose of X-rays is incident on the entire surface of the phosphor layer, the support of the phosphor layer A band-shaped portion in which the amount of light emitted from the surface opposite to the body extends from the center of one end of the intensifying screen toward the center of the opposite end, and an end of the band-shaped portion that is continuous with the band-shaped portion. A band-shaped high-sensitivity part for tracheal sensitization that overlaps the thoracic vertebrae, a trachea and bronchi that overlap the thoracic vertebrae, and a bronchus that overlaps the heart, so that the area that spreads out in an approximately triangular shape from the thoracic vertebrae to the other end is larger than the other parts. A highly sensitive part for sensitization is formed so that a readable lung field image, a trachea and bronchus image superimposed on the thoracic vertebrae, and a bronchus image superimposed on the heart can be projected on the same X-ray film. Intensifying screen for chest X-ray photography. 3. In an intensifying screen consisting of a support and a phosphor layer provided on the support, when the same dose of X-rays is incident on the entire surface of the phosphor layer, the support of the phosphor layer The thoracic vertebrae are formed so that the amount of light emitted from the surface opposite to the body is greater in the band-shaped part extending from the center of one end of the intensifying screen to the center of the opposite end than in other parts. A first intensifying screen having overlapping band-like high-sensitivity parts for sensitizing the trachea and bronchus, and an intensifying screen comprising a support and a phosphor layer provided on the support, When the same dose of X-rays is incident on the entire surface of the body layer, the amount of light emitted from the surface of the phosphor layer opposite to the support varies from the center of one end of the intensifying screen to the center of the opposite end. The thoracic vertebrae is formed so that the number of parts is larger than that of other parts in the belt-like part extending toward the upper part of the body, and the part that extends from the end of the belt-like part to the other end in a substantially triangular shape. It consists of a combination of a band-shaped high-sensitivity part for tracheal sensitization and a second intensifying screen having a high-sensitivity part for bronchial sensitization that overlaps the trachea and bronchi that overlap the thoracic vertebrae, and the heart, and that An intensifying screen for chest X-ray photography, characterized in that it is capable of projecting a lung field image that can be interpreted as an image, a trachea and bronchus image superimposed on the thoracic vertebrae, and a bronchus image superimposed on the heart.