JPS6146946A - Radiation image reading method - Google Patents

Abstract

PURPOSE:To obtain plural sheets of images by irradiating a radiant ray once by constituting a fluorescent material layer of plural kinds of accelerated phosphorescent fluorescent materials having each different accelerated phosphorescence excitation energy, executing an accelerated phosphorescence excitation by an accelerated phosphorescence excitation energy being suitable for the respective fluorescent materials, and reading the image. CONSTITUTION:An accelerated phosphorescent fluorescent material 105 and 106 having each different an accelerated phosphorescence excitation energy depending property of an accelerated phosphorescence light emitting efficiency are contained in an accelerated phosphorescent fluorescent material layer 104 of a radiation image converting panel 103. In this state, a radiant ray is irradiated to an object to be photographed 102 from a radiation source 101, transmitted through the object to be photographed 102 and absorbed by the fluorescent material 105 and 106. Subsequently, read of the fluorescent material 105 is executed by irradiating an accelerated phosphorescence excitation light 202 of an accelerated phosphorescence excitation energy being suitable for the fluorescent material 105 from a read light source 201. Next, read of the fluorescent material 106 is executed by irradiating an accelerated phosphorescence excitation light 302 of an accelerated phosphorescence excitation energy being suitable for the fluorescent material from a read light source 301. In this way, plural sheets of image data can be obtained by irradiating the radiant ray once.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a radiation image conversion method using a photostimulable fluorophore, and more specifically relates to a radiation image conversion method using a photostimulable fluorophore. The present invention relates to a radiation image reading method using a radiation image conversion panel containing a body.

(Prior Art) Radiographic images such as X-ray images are often used for medical purposes. Conventionally, in order to obtain this radiographic image, a so-called radiographic method has been used in which a radiographic film made of a silver salt photosensitive material and an intensifying screen are combined. However, in recent years, with the advancement of radiographic image diagnostic technology, methods for obtaining radiographic images without using radiographic films made of silver salt photosensitive materials have been devised.

In such a method, the radiation transmitted through the object is collected by some kind of phosphor KWJc, and then this phosphor is excited by, for example, light or thermal energy, so that this phosphor becomes the above-mentioned 1 & There is a method in which the radiation energy accumulated in the body is emitted as fluorescent light, and this fluorescent light is detected and imaged. Specifically, for example, British patent 1,46
No. 2,769 and Japanese Unexamined Patent Publication No. 51-29889 disclose methods using heat-stimulable phosphors as the phosphors.

This method uses a radiation image conversion panel with a heat-stimulable phosphor layer formed on a support.The heat-stimulable phosphor layer of this radiation image conversion panel absorbs the radiation that has passed through the subject. Then, radiation energy corresponding to the radiation transmittance of each part of the subject is accumulated to form a latent image, and then the heat-stimulable phosphor layer is heated to excite the radiation and accumulated in each part of the panel. The radiation energy is extracted as a light signal, and a radiation image is obtained depending on the intensity of this light.

Further, for example, US Pat. No. 3,859,527 and Japanese Patent Application Laid-Open No. 55-12144 disclose a method of using a glittering phosphor as the phosphor. This method uses a radiation image conversion panel in which a photoluminescent phosphor layer is formed on a support. After forming a latent image as described above, the photoluminescent phosphor layer is stimulated. By scanning with light, the radiation energy accumulated in each part of the panel is extracted as a light signal and a radiation image is obtained. This final image may be reproduced as a hard copy or on a CRT.
You can play it on top.

By the way, there is currently almost no description regarding the photostimulable phosphor layer of the radiation image conversion panel used in such a radiation image conversion method, but in general, the above-mentioned Japanese Patent Application Laid-Open No. 12144/1983 describes As shown in
It consists of a stimulable phosphor layer. however,'
If there is only one R-exhaustible phosphor layer, most of the accumulated radiation energy will be released by just one photostimulation excitation, and multiple pieces of radiation image data will be generated by one radiation irradiation. It was impossible to obtain.

On the other hand, several methods are known to obtain data on a plurality of radiation images through one radiation irradiation. As a specific method, for example, Japanese Patent Application Laid-Open No. 11399/1983 discloses a method in which multiple radiation image conversion panels are stacked and irradiated with radiation at the same time, and these multiple radiation image conversion panels are sequentially stimulated. However, this method requires multiple radiation image conversion panels, which is difficult to handle during radiation irradiation. However, the reading device for obtaining radiographic image data has the disadvantage of being complicated and bulky.

Further, as another method, for example, Japanese Patent Application Laid-open No. 56-1140
No. 1.1 discloses a method of using a radiation image conversion panel in which a stimulable phosphor layer is coated on both sides of a single support. However, in this method, even if one photostimulable phosphor layer of one support is scanned with photostimulable excitation light, the photostimulable excitation light does not reach the other photostimulable phosphor layer. The disadvantages were that the support was colored blue or the like, that it was necessary to provide a light reflective layer as an intermediate layer between the support and the stimulable phosphor layer, and that the radiation image conversion panel was expensive. . Moreover, with this method, increasing the film thickness of the support will cause a large difference in the distance from the subject to each photostimulable phosphor layer of the radiation image conversion panel. When radiation is irradiated through an object, the image size differs between the stimulable phosphor layers, and the images are misaligned during overlay processing. On the other hand, if the film thickness of the support is made smaller, the strength of the support will decrease and its function as a support will deteriorate. It has a drawback that the image quality of the obtained radiographic image is significantly deteriorated due to cracks or cracks in the i.

In addition, in this method, the stimulable phosphor layer is located on both sides of the support, so it is difficult to transport during the radiation image reading method.
The stimulable phosphor layer of the radiation image conversion panel is easily scratched, and the quality of the radiation image obtained deteriorates when used repeatedly.

(Object of the present invention) The present invention was made in view of the above-mentioned drawbacks of radiation image conversion panels using photostimulable phosphors.
It is an object of the present invention to provide a radiation image conversion method and a radiation image reading method in which a plurality of pieces of radiation image data can be obtained by one radiation irradiation.

Another object of the present invention is a radiation image conversion method and the radiation image reading method, which can easily and accurately detect accumulated record information of the radiation image before obtaining a visible image for observation and interpretation of the radiation image. It is possible to provide the following.

(Creation of the Invention) In order to achieve the above object, the present inventors have conducted intensive research on a radiation image conversion method using a photostimulable phosphor and a method for reading the radiation image. As a result, each photostimulable phosphor has its own unique photostimulation energy distribution.
It has been found that the photostimulable luminescence efficiency is maximized when the individual photostimulable phosphors are excited with matched photostimulation excitation energies.

That is, by utilizing the above phenomenon, a stimulable phosphor layer containing at least two types of stimulable phosphors whose stimulable luminescence efficiency differs in their dependence on stimulable excitation energy can be formed into a stimulable phosphor layer containing each stimulable phosphor. By superimposing the same number of photostimulable fluorophores as the number of types of photostimulable fluorophores with the photostimulation excitation energy matched to the light body, 91
Multiple radiation images can be obtained with one radiation irradiation.

Based on the above-mentioned findings, an object of the present invention is to stimulate a radiation image conversion panel having a photostimulable phosphor layer by photostimulating the radiation image stored and recorded on the radiation image conversion panel. In the radiation image reading method of photoelectrically reading the radiation image, the photostimulable phosphor layer contains at least ZaI type photostimulable phosphors whose photostimulable luminescence efficiencies have different photostimulable excitation energy dependencies. , achieved by a radiation image reading method characterized in that each photostimulable phosphor is stimulated with photostimulation excitation energy suitable for each photostimulable phosphor and read to obtain a plurality of radiation image data. be done.

In the present invention, a photostimulable phosphor refers to a phosphor that can be stimulated by prior stimulation (stimulation excitation), such as thermal, mechanical, chemical, or electrical, after being irradiated with the first light or high-energy radiation. ,
A phosphor that exhibits stimulated luminescence corresponding to the amount of initial light or high-energy radiation irradiated. In particular, those in which photostimulation occurs first are called photoluminescent phosphors, and those in which photostimulation occurs thermally are called thermostimulable phosphors.

Here, light includes visible light, ultraviolet light, and infrared light among electromagnetic radiation, and high-energy radiation includes X-rays, gamma rays, beta rays, alpha rays, and neutron rays.

In addition, in the present invention, photostimulable phosphors whose photostimulable luminescence efficiencies differ in dependence on photostimulation excitation energy broadly refer to phosphors that require different types of stimulation energy for causing the photostimulable phosphors to emit stimulated light. It is a light substance, and more specifically refers to a phosphor whose peaks in the stimulated excitation spectrum differ from each other by 50 nm or more.

The present invention will be explained in detail below.

The photostimulable phosphor used in the radiation image conversion panel according to the present invention is a phosphor that exhibits stimulated luminescence when stimulated after being irradiated with radiation, as described above, and at least The two types may be any type of phosphor as long as they have different photostimulation excitation energy dependencies.

Examples of combinations of photostimulable phosphors with different photostimulation energies include photoluminescent phosphors and heat-stimulable phosphors; in photoluminescent phosphors, the peak of the photostimulable spectrum is 50
Examples include phosphors that differ by nm or more, and phosphors that differ from each other in photostimulation temperature among heat-stimulable phosphors.
It is not limited to this.

In the radiation image conversion panel according to the present invention, the photostimulable phosphor used is described in, for example, JP-A No. 48-80487.
y.

At least lal among Tb and Tm, and χ is o5
A phosphor expressed by
(However, A is either Ho or Dy, and 0
．． 001≦χ≦1molti),
SrSO4 described in JP-A-48-80489
: A phosphor expressed by Az (where A is at least one of Dy, Tb and Tm, and χ is 0.001≦χ and 1 molti), described in JP-A No. 51-29889. Na2804, CaSO4 and B
At least 1f of Mn, Dy and Tb in aSO4 etc.
Phosphor added with ffi, JP-A-52-3P487K
Describe tL te Its Le BeO, Li F, M
Fluorescent materials such as g5O< and CaF2, JP-A-53-392
L42B40y described in No. 77: Cu,
Fluorescent material such as Ag, Liz C1 (B202) χ:Cu (However, χ
is 2×χ≦3), and LizO・(B202)r:
A phosphor such as Cu+Ag (where χ is 2<χ≦3), SrS described in US Pat. No. 3,859,527:
Ce.

SmX5rS: Eu, Sm, LazO Goose S:
Examples include phosphors represented by Eu, Sm, (znt+Cd)S::Mn, and X (where X is halogen). In addition, ZnS described in JP-A No. 55-12142
: Cu, Pb phosphor, general formula is BaO・zAt
zoa: barium aluminate phosphor coated with Eu (however, 0.8≦χ≦10), and whose general formula is M'0.
zsi03:A (However, MI is Mg, Ca,
Sr, Zn.

17A in Cd or Ba is Co, Tb, Eu, Tm
,Pb,TL.

At least one of Bi and Mn, χ is 0.5
≦χ≦2.5). In addition, the general formula % formula %: (However, X is at least one of Br and Ct),
χ, y and e are respectively 0≦χ+y≦0.6, χy〆0
and 10≦6≦5×10), the general formula of the alkaline earth fluorohalide phosphor described in JP-A-55-12144 is LnOX:χA (however, Ln represents at least one of La, Y, Qd, and Lu, X represents Ct and/or Br, A represents Ce and/or Tb, and χ represents a number satisfying 0<χ<0.1.) The general formula of the phosphor represented by JP-A-55-12145 is (Bit-zM"z) FX: yA (where Ml
is at least one of Mg, Ca, Sr, Zn and Cd, X is at least one of CA, Br and 1 -, A Fi Eu, Tb, Ce, Tm,
Dy, Pr, Ho.

At least one of Nd, Th, and Er, and χ and y represent numbers satisfying the conditions of 0≦χ≦0.6 and 0≦y≦0.2. ), JP-A-55-8
The general formula described in No. 4389 is BaFX:χC
e, yA (However, X is at least one of CA, Br and 1, A is In, Tt, Gd, Sm and Zr
Out of the house! At least one of
It is 2. ), Japanese Patent Application Laid-Open No. 55-160
The general formula described in No. 078 is M FX zA : yLn (where Ml is N, at least one of Ca, Sr, Zn and Cd, and A is BeO, MgO, CaO, SrO.
+BaO, ZnO, A2zOx tY203, La
2O3, In2O5, S i02 + Ti0z t
Zr0t * Ge0z.

Snow r Nbz05, Ta1ls and Th
At least one building of O2, Ln is Eu, Tb, C
e, Tm, D)', Pr, Ho, Nd.

is at least one of Yb, Er, Sm, and Gd, and X is at least one of C2, Br, and G, and is 5XIQ''-5≦χ≦0.5 and 0<y≦0, respectively.
．． This is a number that satisfies the condition 2. ) Rare earth element-activated divalent metal fluorohalide phosphors, whose general formulas are ZnS:A, CdS:A, (Zn, Cd
)S:A, ZnS:A,X and CdS:A,X(
However, A /ri Cu + Ag + Au or M
n, and X is halogen. ), the general formula CI) or [11) described in JP-A-57-148285, the general formula (1) χMs (PO4)!・Nn:yA general formula (If) Ms (PO4)2: )'At
In the formula, M and N are Mg, Ca, Sr, and Ba, respectively.

At least one of Zn and Cd, X is F, C2°B
At least [4 among r and l, A is Eu, Tb
.

Ce l Tnl l Dy l Pr, Ho,
Nd, Yb, ET, Sb・, Tt,
Represents at least one of Mn and Sn. Also,
χ and y are numbers that satisfy the condition of 0 and χ≦6.0≦y≦1. ), and the general formula [kawa] or [■] general formula [1[1,l nReX5 ・mAXz:
zEu general formula CI￥) nReXa ・mAXz
: zEu, ySm (wherein, Re is La, G
At least one of d, Y, and Lu, A is an alkaline earth metal, and at least l of Ba, Sr, and Ca
a! , X and X include at least one of F, C2, Brc7). Moreover, χ and y are I X 10-'<
Z < 3 X IF', I XIO'< y <
It is a number that satisfies the condition ``I
The stimulable phosphor used in the radiation image conversion panel of the present invention, however, satisfies the condition: The material is not limited to phosphors, but any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with a stimulable excitation source may be used.

The average particle size of the stimulable phosphor used is appropriately selected within the range of 0.1 to 100 μm, taking into consideration the sensitivity and granularity of the radiation image conversion panel.

More preferably, those having an average particle size of 1 to 30 pm are used.

In the radiation image conversion panel according to the present invention, it is sufficient that the stimulable phosphor layer contains at least two types of stimulable phosphors whose stimulable luminescence efficiencies differ in the stimulable excitation energy dependence. An example of this is a radiation image conversion panel having a layer structure as shown below.

(1) A radiation image conversion panel comprising one photostimulable phosphor layer containing at least 2s-class photostimulable phosphors whose photostimulable luminous efficiencies differ in dependence on photostimulation excitation energy.

(2) The photostimulable phosphor layer is composed of at least two layers, and the at least two layers of the photostimulable phosphor layer have different photostimulation excitation energy dependencies of the stimulated luminous efficiency. A radiation image conversion panel made of fluorescent phosphors.

When using two types of stimulable phosphors whose stimulable luminescence efficiencies differ in dependence on stimulable excitation light, their usage ratio varies depending on the purpose of use, but is 1:1 to 1:0.05 (weight ratio). In the radiation image conversion panel according to the present invention, the above-mentioned photostimulable phosphor is generally dispersed in a suitable binder and coated uniformly by a conventional coating method. Examples of binders used as layers include proteins such as gelatin, polysaccharides such as dextran or gum arabic, polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, vinylidene chloride-vinyl chloride; polymers, polymethyl methacrylate. , vinyl chloride-vinyl acetate copolymer, polyurethane, cellulose acetate butyrate, polyvinyl alcohol silicone resin, polysiloxane resin, etc. are used. Generally, the binder is stimulable. It is used in an amount of 0.01 to 1 part by weight per 1 part by weight of the phosphor. However, from the point of view of the sensitivity and sharpness of the obtained radiation image conversion panel, it is preferable that the amount of the binder is small, and from the viewpoint of ease of application, it is more preferable to use the binder in the range of 0.03 to 0.2 parts by weight. In the radiation image conversion panel according to the present invention, the film thickness of the photostimulable phosphor I- is determined by the characteristics of the intended radiation image conversion panel, the properties of the photostimulable phosphor, the binder and the photostimulable fluorescein. Although it varies depending on the mixing ratio with the photon, generally, when the stimulable phosphor layer consists of one layer, it is 10 μm - 1200 μm.
It is preferably selected from the range of m, more preferably 10 μm.
It is more preferable that the thickness be selected from the range of 800 μm. In addition, when the photostimulable phosphor layer consists of two or more layers, the thickness of each layer is preferably selected from the range of 10 μm to 800 μm. When more than one layer of photostimulable phosphor layers is used, a photostimulable light blocking layer may be used in combination with the two layers. The photostimulation excitation light blocking layer can be made of any material as long as it reflects and/or absorbs the photostimulation excitation light, but a material that is flexible in handling as a radiation image conversion panel is preferred. From this point, for example, At, Pb*Ni, CusZ
Metal sheets made of metals such as n, Ag t Au, Pt + Fe and alloys thereof, plastic film sheets such as cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film, and However, when using plastic film sheets and paper as the photostimulation excitation light blocking layer, these sheets themselves have very little ability to block photostimulation excitation light. For this reason, it is necessary to color the sheet itself so that it serves as a photostimulation excitation light reflection layer or an absorption layer. In order for the sheet to become a photostimulation excitation light reflecting layer, the sheet may be colored with a white pigment, etc., and in order to become a photostimulation excitation light absorption layer, the sheet may be colored in a photostimulation excitation light absorption layer. It may be colored with a pigment that absorbs light or a black pigment.

Instead of coloring the sheet itself, a stimulated excitation light reflecting layer or an absorbing layer may be provided on one or both sides of the sheet. As the stimulated excitation light reflection layer, a metal reflection layer may be provided on the surface of the sheet by a method such as vapor deposition or sputtering, or a white pigment layer or the like may be provided by a method such as coating. As the photostimulation excitation light absorption layer, a pigment or a black pigment that absorbs photostimulation excitation light may be provided on the surface of the sheet by a method such as coating.

Furthermore, after coloring the sheet as necessary, a photostimulation excitation light reflection layer or an absorption layer may be provided on the surface thereof, or a photostimulation excitation light reflection layer may be provided on one side of the sheet and a photostimulation excitation light reflection layer is provided on the other side. An excitation light absorption layer may also be provided.

Further, the photostimulation excitation light blocking layer may be formed by dispersing white powder, black powder, etc. in a resin and applying the same in addition to the sheet-like material.

The thickness of the stimulated excitation light blocking layer varies depending on the intensity of the stimulated excitation light used and the stimulated excitation light transmittance of the stimulated excitation light blocking layer, but is practically 1000 μm or less, preferably 4 μm or less.
00 μm or less.

In the radiation image conversion panel according to the present invention, a support is generally used. However, when the above-mentioned photostimulable light blocking layer is provided, this layer can serve as a support for supporting the photostimulable phosphor layer. However, if the photostimulation excitation light blocking layer is thin or has great flexibility, a support is required.

Supports include various polymers, glass, etc.
Sheet materials made from various materials can be used, but materials that can be processed into flexible sheets or rolls are preferred for handling as radiation image conversion panels.From this point of view, for example, Particularly preferred are plastic films such as acetate film, polyester film, polyethylene tere-7 tallate film, polyamide film, polyimide film, triacetate film, and polycarbonate film.

Furthermore, in the radiation image conversion panel according to the present invention,
Generally, a protective layer is provided to protect the stimulable phosphor layer physically or chemically.

This protective layer may be formed by directly applying a coating solution for the a-retaining layer onto the photostimulable phosphor layer, or by applying a separately formed protective layer in advance onto the photostimulable phosphor layer. You may wear it.

As the material for the protective layer, ordinary protective layer materials such as cellulose acetate, nitrocellulose, polymethyl methacrylate, polyvinyl butyl, polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate, polyethylene, vinylidene chloride, and nylon are used. It will be done. The thickness of these protective layers is generally 1 μm to 40 μm.
It is preferably about pm.

The above-mentioned aNI is selected because it transmits stimulated luminescence and stimulated excitation light.

Further, in the radiation image conversion panel according to the present invention, an adhesive layer may be provided between the photostimulable phosphor layer and the photostimulable light blocking layer, the protective layer, or the support.

Furthermore, in the radiation image conversion panel of the present invention, for the purpose of improving sharpness, white powder is added to the stimulable phosphor layer of the radiation image conversion panel as disclosed in JP-A-55-146447. It may be dispersed or
Radiation iI! as disclosed in No. 163500. I
IIJ! The stimulable phosphor layer of the conversion panel may be colored with a coloring agent that absorbs the stimulable excitation light. Exhaustive excitation energy includes light energy, thermal energy, mechanical energy, etc., but light or thermal energy is preferable from the viewpoint of operation, percentage, etc.

As a light source of optical energy, Ar+ laser, He-Cd
There are lasers such as lasers, He-Ne lasers, Kr lasers, Dye lasers, YAG lasers, CO□ lasers, and semiconductor lasers, and lamps such as L'ED and tungsten lamps. It is excellent in terms of confidentiality.

Examples of the excitation heat source include infrared lasers such as YAG lasers, CO2 lasers, and semiconductor lasers, various heaters, hot air, and thermal heads.

In the case of an embodiment in which thermal stimulation excitation is performed, it is preferable to use heat-resistant materials for panel components such as a binder and a support.

- Next, the present invention will be explained using the drawings.

FIG. 1 shows one example of an embodiment of the present invention, and is a schematic diagram of a radiation image recording system including a radiation image reading device.

In the present invention, in principle, the stimulable fluorophores used are superimposed for excitation, so the excitation order is expressed by numbering 1st, 2nd, etc. In Fig. 1, 1 is the photographing department;
Reference numeral 2 denotes a first M, a take-up part, for reading the radiation image accumulated in the first photostimulable phosphor, and 3 refers to a part for reading the radiation image accumulated in the second photostimulable phosphor. The second reading section 4 represents a reproduction/recording section.

In the imaging unit 1, the radiation emitted from the radiation source 101 toward the subject 102 passes through the subject 102, and then
A first stimulable phosphor 105 and a second stimulable phosphor whose stimulable luminescence efficiency differs in the stimulable excitation energy dependence contained in the stimulable phosphor layer 104 of the radiation image conversion panel 103 It is absorbed by the body 106, and a radiation image of the subject is stored and recorded. Next, this radiation image conversion panel 103 is sent to the first reading section 2.

In the first reading section 2, the first photostimulable excitation light 202 from the reading light source 201 is converted into a radiation image by a light deflector such as a galvanic mirror (radiation image conversion). By one-dimensionally deflecting upward and sub-scanning the radiation image conversion panel 103, the entire surface of the stimulable phosphor layer 104 is irradiated with the stimulable excitation light 202. When the stimulable excitation light 202 is irradiated in this way, the stimulable excitation energy distribution is matched to the first stimulable excitation light 202 contained in the stimulable phosphor layer 104 of the radiation image conversion channel 103. The first photostimulable phosphor 105 emits stimulated luminescence that is proportional to the radiation energy stored and recorded therein. After this light emission passes through a filter 203 that filters only the stimulated excitation light 202,
The output of the photoelectric converter 204 is amplified by the amplifier 205. The radiation image conversion panel 103, which has finished reading the first photostimulable phosphor 105, 2 is sent to the reading section 3.

In the second reading section 3, in the same manner as in the first reading section 2, the second stimulated excitation light 302 from the reading light source 301 is transmitted to the radiation image conversion panel 103 by an optical polarizer such as a galvanometer mirror. Stimulating excitation light 302 is irradiated over the entire surface of the stimulable phosphor layer 104 by being one-dimensionally deflected onto the stimulable phosphor layer 104 and sub-scanning the radiation image conversion panel 103. be done. When the stimulated excitation light 302 is irradiated in this way, the radiation image conversion panel 10
A second photostimulable phosphor 106 having a photostimulable excitation energy distribution matched to the second photostimulable excitation light 302 contained in the photostimulable phosphor layer 104 of No. 3 is stored and recorded therein. A filter 30 that emits stimulated luminescence proportional to radiation energy and cuts only the stimulated excitation light 302 from this luminescence.
3, enters the photoelectric converter 304, is photoelectrically converted, and is amplified by the amplifier 305. The final output 206 of the first reading section 2 and the final output 306 of the second reading section 3 are separately The reproduction/recording unit 4 may output a visible image to a hard copy, CRT, etc., or it may be electrically subjected to overlapping processing or subtraction processing and output as a single visible image to a hard copy, CRT, etc. It's okay.

The reproducing/recording section 4 in FIG. 1 shows an embodiment in which a photosensitive material is used as a note copy. modulated based on the image signal,
A photosensitive material 4 such as photographic film is scanned by a scanning mirror 404.
05 is scanned. Further, the photosensitive material 405 is exposed to the laser beam 4
Since the sub-scanning is performed in synchronization with the scanning of 03, the photosensitive material 40
A radiation image is output on 5.

The radiation image conversion spring (1y of 103) photostimulable phosphor 105 and the second photostimulable phosphor 106 do not need to be read in this order, and even if they are reversed, they can be read at the same time. It's okay.

Furthermore, the radiation information accumulated and recorded in the radiation image conversion panel 103 is grasped from the final output 206 of the first reading unit 2, and based on this information, the sensitivity of the photoelectric converter 304 of the second reading unit 3 and the amplifier 305 are determined. The amplification factor, etc. of It can be used to adjust the image quality to a suitable level.More specifically, this will be explained with reference to the block diagram shown in FIG. 2.In FIG. Image signal output, 305 is an amplifier of the second reading section 9, and 304 is a photoelectric converter of the circuit section.

307 is a control circuit that performs image control based on the information of the image signal output 206, and the control by 307 is the aforementioned photoelectric converter 30.
The optical modulator 401 controls the four amplifiers 305, A/D converters 308, and signal processing circuits 309, prepares the image signals 306, and causes the optical modulator 401 to produce an image suitable for observation and interpretation in the reproducing/recording section 4.

That is, the output of the photoelectric converter 304 is amplified by an amplifier 305, converted by a Le [F] converter 308, and then subjected to signal processing by a signal processing circuit 309 so as to obtain a radiation image with excellent diagnostic suitability. 0 photoelectric converter 30
4 and the amplification factor of the amplifier 305, the recording scale factor of the A/D converter 308, and the signal processing conditions in the signal processing circuit 309 are based on the accumulated record information of the radiation image obtained in the first reading section 2 as described above. The image signal 306 output from the signal processing circuit 309 is transmitted to the recording unit 4.

FIG. 3 shows another embodiment of the present invention, which is similar to FIG. 1 except that the directions of incidence of the stimulated excitation light on the radiation image conversion panel 103 in the first reading section 2 and the second reading section 3 are opposite. Same as the implementation! It's like that.

FIG. 4 shows yet another embodiment of the present invention, which is the same as the embodiment shown in FIG. 1 except that a thermal head 207 is used at 9 instead of the stimulated excitation light source 201 of the first reading section 2.

It goes without saying that the present invention is not limited to the embodiments described above, and that various modifications can be made.

(Effects of the Invention) As explained above, according to the radiation image reading method of the present invention, it is possible to obtain radiation image data of a plurality of sheets by one radiation irradiation.

In addition, a photostimulation excitation light blocking layer is not required, or even if it is necessary, the film thickness can be made sufficiently small, making it possible to obtain high-quality radiation images without causing image shift during overlay processing, etc. .

Further, according to the radiation image reading method of the present invention, it is possible to detect accumulated recorded information of a radiation image easily and accurately by the first reading.

Furthermore, according to the radiation image reading method of the present invention, there is no reduction in the accumulated radiation energy that should be emitted during the second reading due to performing the first cystectomy. It becomes possible to prevent a decrease in system sensitivity.

Furthermore, since the first reading can be performed with high stimulated excitation light energy, it is possible to accurately grasp the accumulated record information of the radiation image recorded on the radiation image conversion panel.

Furthermore, according to the radiation image reading method of the present invention, it is possible to accurately grasp the accumulated record information of radiation images recorded on the radiation image conversion panel in advance, so that a reading system having an exceptionally wide dynamic range can be used. Even if the reading gain is appropriately adjusted based on the accumulated recorded information, it is possible to always obtain radiographic images with excellent diagnostic suitability even if the imaging conditions etc. change.

In addition, since the recording pattern of the radiation image recorded on the radiation image conversion panel can be known in advance, diagnostic suitability can be improved by applying signal processing according to the recording pattern to the electrical signal after @2 reading υ. It becomes possible to obtain excellent radiographic images.

The present invention has many effects as described above and is industrially very useful.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a radiation image conversion method using the radiation image conversion panel of the present invention. FIG. 2 is a block diagram of an image adjustment system. FIGS. 3 and 4 are 1 is a schematic explanatory diagram of different embodiments of the present invention. 1... Photographing unit 101... Radiation 1 source 102... Subject 103... Radiation image conversion panel 104... Stimulable fluorescence Body layer 105...First photostimulable phosphor 106...Second photostimulable phosphor 107...Support 2...First reading section 201...Le II excitation Light source 202... Stimulated excitation light 203... Filter 204... Photoelectric converter 205... Amplifier 206... Output 3... Second reading section 301... Stimulated excitation light source 302...・Photostimulation excitation light 303...Filter 304...Photoelectric converter 305...Amplifier 306...Output 4...Reproduction and recording department agent Patent attorney No a3 Father-in-law Figure 1 z Figure 4 3 Afternoon

Claims (1)

[Claims] A radiation image reading method in which a radiation image conversion panel having a photostimulable phosphor layer is stimulated and excited to cause a radiation image stored in the radiation image conversion panel to undergo photostimulation emission, and the radiation image is read photoelectrically. In the method, the photostimulable phosphor layer contains at least two types of photostimulable phosphors having different photostimulable excitation energy dependencies of the photostimulable luminescence efficiency, and each photostimulable phosphor is A radiation image reading method characterized in that a plurality of radiation image data are obtained by reading the photostimulable phosphor by photostimulating it with photostimulation excitation energy suitable for the photostimulable phosphor.