JPS5866935A - Radiation picture information recording and reading device - Google Patents

Abstract

PURPOSE:To permit the reuse of a storage type phosphor without giving any damage thereto and to obtain homogeneous reproduced pictures with respect to the cyclic reuse of said phosphor in a device by performing recording and reading of pictures alternately while holding a recording body fixed. CONSTITUTION:When the transmitted radiation picture of an object 5 is stored and recorded on the storage type phosphor 2 of a recording body 3 and the phosphor 2 is scanned by excitation light 6, said phosophor emits glittering light according to the picture information, which light is inputted to a photodetector 8 and is photoelectrically converted. The corresponding electrical picture signal is outputted therefrom. The surface of the phosphor 2 is wiped by a moving cleaning roll 1, and a stage carrying a photodeflector 7, the photodetector 8, etc. is returned from the body 3 to a stand-by position. A light source 10 for erasing is lighted for a prescribed time, and the phosphor 2 is reset to a reusable state. During the work, the storage type phosphor is not conveyed.

Description

[Detailed Description of the Invention] The present invention stores and records radiation image information on a stimulable phosphor,
Next, excitation light is irradiated onto this, and the light that emits stimulated light is detected according to the accumulated and recorded image information, and the image information is read and converted into an electrical signal.Later, this read image information is converted into a visible image. The present invention relates to a radiation image information recording/reading device for reproducing radiation image information, and more particularly to a radiation image information recording/reading device in which a stimulable phosphor is cyclically reused within the device.

When certain phosphors are irradiated with radiation (Xi, alpha, beta, r-rays, ultraviolet, etc.), a portion of the energy of this radiation set is stored in the phosphor, and then the phosphor is When irradiated with Q excitation light such as visible light, the phosphor exhibits stimulated luminescence according to the accumulated Baenerky light. A phosphor exhibiting such properties is called a storage phosphor.

Using this stimulable phosphor, emissive fine image information of a human body, etc. is recorded on a sheet of stimulable phosphor, and this is scanned with excitation light to produce stimulated luminescence. A method has been proposed in which an image signal is obtained by photoelectrically reading the image, and this image signal is processed to obtain an image suitable for diagnosis.

(For example, JP-A-55-12429, JP-A-56-1139)
No. 5, No. 55-163472, No. 56-104645
(No. 55-116340, etc.) This final image may be reproduced as a hard copy (CRT).
Even if it's the one you played above. In any case, in these four radiation image information recording and reproducing methods, a stimulable phosphor sheet (strictly speaking, this can take various forms such as a panel-like sheet or a drum-like sheet, but is generally referred to as (hereinafter referred to as a "-sheet") does not ultimately record image information, but temporarily carries image information in order to provide the image to the final media such as the one mentioned above. This Nf) phosphor sheet may be used repeatedly, and such repeated use is extremely economical.

In order to reuse the stimulable phosphor sheet as described above, it is necessary to use the radiation energy accumulated in the stimulable phosphor sheet after the stimulated luminescence light has been read, for example in Japanese Patent Application Laid-Open No. 56-113.
The stimulable phosphor sheet may be used again for recording radiographic images by emitting it to erase the radiation set image by a method such as that shown in No. 92, No. 56-12599. In the actual device, the stimulable phosphor sheet after the reading is completed is supplied to an image erasing device by a conveying means such as a belt conveyor, and the stimulable phosphor sheet from which the radiation image has been erased is further processed as described above. It is also possible to save labor by sending the image back to the image recording unit using a suitable conveyance means.

However, it is extremely difficult to design and manufacture a conveying means that can convey a sheet-like substance such as the above-mentioned stimulable phosphor sheet without causing problems such as clogging or catching.・Furthermore, it goes without saying that the above-mentioned stimulable phosphor sheet must not be damaged by scratches or the like during transportation.
From this point of view as well, designing and manufacturing the above-mentioned conveying means becomes difficult. Also, for example, a certain sheet may be played immediately after recording,
If a certain sheet is temporarily stored at the recording edge and then reproduced together with a series of other sheets, the order in which the sheets are used will be completely different and the sheets will be returned to the image recording unit. The sheets that are used are gradually new and old.
It becomes a mixture of the two. If new sheets and old sheets coexist in this way, the quality of the reproduced image will vary depending on the sheet used, making it impossible to obtain a homogeneous reproduced image. Therefore, it is desirable to replace old sheets with new sheets as appropriate, but in order to replace such sheets, it is necessary to
The quality of the reproduced image from each sheet must be inspected, or the number of times it has been used must be managed to determine whether the sheet should be replaced with a new one or whether it should be continued to be used. It is extremely troublesome to control the quality of each sheet.

The present invention has been made in view of the above circumstances, and it is possible to reuse a stimulable phosphor for recording radiographic images without damaging it, to obtain a homogeneous reproduced image, and to make it possible to obtain a uniformly reproduced image. A recording body formed by laminating a stimulable phosphor capable of accumulating and recording radiation energy on a support for recording and reading radiation image information that is easy to manufacture and manage; an image recording unit that accumulates and records a transmitted radiation image of a subject on the stimulable phosphor by irradiating it with radiation, and scans the stimulable phosphor that is disposed near the recording body and stores the radiographic image; an image reading unit having an excitation light source that emits excitation light; and a photoelectric reading unit that reads photostimulated light emitted from a stimulable phosphor scanned by the excitation light to obtain an image signal; It is characterized by comprising an erasing means for emitting residual radiation energy on the stimulable phosphor prior to recording an image on the stimulable phosphor after image reading. be. The apparatus of the present invention performs the reading operation of radiographic images as described in 5 above, and the electrical image signals obtained by the reading operation are input to various known reproduction apparatuses. Needless to say, etc. can be obtained. It is possible to record an image from one side of the recording body and read the image from the other side of the recording body while keeping the recording body completely fixed. It becomes possible. If image recording and reading are performed alternately with the recording medium fixed in this way, unlike the case where the sheet-shaped stimulable phosphor is transported one by one, the stimulable phosphor will not be damaged. In addition, the construction of the device is significantly simplified, since no mechanism for transporting the stimulable fluorescer is required.

Furthermore, since one stimulable phosphor is used repeatedly, sheet management is extremely easy and a stable and homogeneous reproduced image can be obtained.

In the present invention, a storage fluorophore refers to radiation (X-rays, α
When irradiated with radiation (beta rays, β rays, r rays, ultraviolet rays, etc.), a part of this radiation energy is accumulated internally, and then when excitation light such as visible light is irradiated, stimulated luminescent light with an amount of light corresponding to the accumulated energy is generated. refers to something that has the property of emitting

In the present invention, it is preferable that the wavelength region of the excitation light and the wavelength region of the stimulated luminescent light do not overlap in order to improve the S/N ratio, and the excitation light source and the stimulable fluorescent light are selected so as to satisfy such a relationship. It is preferable to choose a light body. Specifically, as disclosed in JP-A-55-12492, it is desirable that the excitation light wavelength be 600 to 700 nnl and the stimulated emission light wavelength be 300 to 5QQnm.

In this way, it emits stimulated luminescence light of 300 to 500 nm,
As the stimulable phosphor that can be preferably used in the present invention, for example, a δ-earth element-activated alkaline earth metal fluorohalide phosphor [specifically, described in JP-A-55-12143] (Bal-x-y, Mgx, C
ay) F'X: aEu2' (where X is at least one of C1 and Br, and X and y are 0<x+y
≦0.6 and xybeO, and a is 10-”≦a≦5×
(Bat-x, Mnx) FX:y
A (where M [I is at least one of Mg, Ca, Sr, SZn and Cd, X is at least one of CI SBr and I, A is Eu, Tb,
Ce, Tm, Dy, Pr.

At least one of Ho1Nd, Yb and E"
(X is 0≦X≦0.6, y is 0≦y≦0.2)
etc.]; ZnS:Cu, Pb1BaO#xA7203:Eu described in JP-A No. 55-12142
(I8L0.8≦X≦10) and MrIO-XSI0
2: A (It l shi M” &'!, Mg.

Ca, Sr, Zn%Cd or Bat, A is Ce,
,Tb.

Eu, Tm, Pb, Tl, Bi f or Mn, and X is 0.5≦X≦2.5); and LnOX:
((B, Ln is at least one of La, Y, Gd and Lu, X is at least one of C1 and Br)
and A is at least one of Ce and Tb; Among the light substances, barium fluorohalides shown as specific examples are particularly preferable because they have excellent photostimulable luminescence.

Furthermore, barium fluorohalide phosphor was developed in Japanese Unexamined Patent Publication No. 56
-2385, 56-2386, to which metal fluoride is added, or the patent application filed in 1972-
The addition of at least one of metal chlorides, metal bromides, and metal iodides as disclosed in No. 150873 further improves stimulated luminescence, and is preferred. As disclosed in Japanese Patent No. 163500, when the phosphor layer of a stimulable phosphor plate prepared using the above-mentioned stimulable phosphor is colored with a pigment or dye, the final image obtained is Sharpness is improved, which is preferable.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Fig. 1 shows a first embodiment of the present invention. A recording body 3 in which the layers are laminated is used for radiographic image storage and recording.
A radiation source 4 is provided at a position facing the support side surface. This radiation source 4 is, for example, an X-ray source, and transmits a transmitted radiation image of a subject 5 placed between this radiation source 4 and a recording medium 3 onto a stimulable phosphor 2 through a support 1 made of a radiation-transparent material. to project. The projected radiation image is recorded on the storage phosphor 2.

At a position facing the phosphor side surface of the recording body 3, there is an excitation light source 6 that emits excitation light such as a laser beam, and the excitation light emitted from the excitation light source 6 is scanned in the width direction of the recording body 30. A light deflector 7 such as a galvanometer mirror, a photodetector 8 that reads the stimulated luminescent light emitted by the stimulable phosphor 2 excited by the excitation light, and a photodetector 8 that receives the stimulated luminescent light. The guiding light transmission means 9 share a common stage (not shown)
It is installed on board. The photodetector 8 is, for example, a Heradon-type photomultiplier tube, a channel plate for photoelectron amplification, or the like, and photoelectrically converts the stimulated luminescence light introduced by the light transmission means 9.

to be detected.

Regarding the material, structure, and usage of the light transmission means 9, see Japanese Patent Application Laid-open Nos. 55-87970 and 56-11397,
56-11 No. 6, 56-11394, 56-
The methods and methods disclosed in No. 1139.8, No. 56-11395, etc. can be used as they are. .

Further, at a position opposite to the surface of the phosphor side of the recording body 3,
An erasing light source io is provided, and a cylindrical cleaning roller 11 is mounted on the stage described above, which is rotated in the direction of the arrow in the figure by a drive unit (not shown). The erasing light source 10 emits radiation energy stored in the stimulable phosphor 2 by irradiating the stimulable phosphor 2 with light included in the excitation wavelength range of the phosphor. For example, JP-A-56-11
A tungsten lamp as shown in No. 392, a halogen lamp, an infrared lamp, a certain C. laser light source, etc. may be optionally used. Note that the radiation energy stored in the stimulable phosphor 2 is disclosed in, for example, Japanese Patent Application Laid-Open No. 111-111.
I'd 56-12599, the erasing light source 10 may be replaced by a heating means, since the stimulable fluorescer can also be emitted by heating.

When the cleaning rollers 1, 1 contact the surface of the recording medium 3 and rotate on the recording medium 3, they remove dust and dirt attached to the surface of the stimulable phosphor 2 of the recording medium 3. If necessary, it may be formed to attract the above-mentioned dust and dirt using electrostatic phenomenon.

The operation of the apparatus of this embodiment having the above structure will be explained below. After the subject 5 is placed between the recording body 3 and the radiation source 4, when the radiation source 4 is turned on, a transmitted radiation image of the subject 5 is accumulated and recorded on the stimulable phosphor 2 of the recording body 3. Ru. After the recording of the radiation image is completed, the excitation light source 6 is turned on,
The stimulable phosphor 2 is scanned by the excitation light emitted from the excitation light source 6.

The excitation light is scanned in the width direction of the recording medium 3 by the optical deflector 7 (main scanning), and is also transmitted from the excitation light source 6. Optical deflector7.
Photodetector8. The stage that fixes the light transmitting means 9 and the cleaning roller 11 is moved from the top 'to the bottom' in the figure, so that the recording body 3 is scanned in the vertical direction (sub-scanning). , can be easily formed using a known linear movement mechanism. When irradiated with the excitation light, the stimulable phosphor 2 accumulates and records the image information and emits stimulated light according to the image information. The photodetector 8 outputs an electrical image signal corresponding to the image information i.

When the stage is moved from above to below for the above-mentioned sub-scanning, the cleaning roller 11 mounted on this stage is rotated. The surface of the stimulable phosphor 20 is swept by the moving cleaning roller 11, and fine dust and flakes are removed from the surface.

When the image reading is completed and the entire surface of the stimulable phosphor 20 is cleaned, the stage equipped with the optical deflector 7, the optical detector 8, etc. is moved upward from the recording medium 3 in the waiting position. It will be returned. Thereafter, the erasing light source 10 is turned on for a predetermined period of time, and a small amount of radiation energy key remaining in the stimulable phosphor 2 after the reading operation and the stimulable phosphor are mixed into the stimulable phosphor 2 (266 Ra and 40 A radiation network emitted from radioactive isotopes such as In cases where the image has been removed and the device has been used for a long period of time, radiation from the radioactive isotopes accumulated in the stimulable phosphor 2 may be present. Radiation energy due to environmental radiation is also released, returning it to a reusable state.

The recording medium 3 that has been cleaned and image erased in the manner described above is used again for radiographic image recording.

As described above, since the device of this embodiment does not transport the stimulable phosphor, the mechanism is extremely simple and can be easily designed and manufactured.

Furthermore, since one recording medium is used repeatedly, sheet management is easy and uniform reproduced images can be obtained.

The electrical image signal outputted from the photodetector 8 may be inputted immediately to a reproducing device to obtain Tokobee or CR'l'' display waste, or it may be digitized and converted into a magnetic tape. - A high-density capture device such as an optical disk, magnetic disk, or optical disk is installed on a patrol bus, etc.
When used for medical diagnostic imaging, the reading record of the image signal is recorded as part of the radiographic image.
If the high-density recording medium such as the one described above is taken back to a medical center or the like and regenerated there, the weight of the moving equipment can be reduced. Also,
The above-mentioned image signal may be input to a reproducing device and a recording medium at the same time. In other words, when used in a hospital, the image signal is transmitted from the radial axis imaging room to the recording medium for record storage, and at the same time, this image signal is transmitted to the CR in the examination room.
It is also possible to transmit the image to a reproducing device such as T, so that it can be used for diagnosis immediately after the image is taken.

In addition, prior to the reproduction of the radiation image 2, it is possible to perform signal processing on the image signal to enhance the image, change the contrast, etc. In addition, in order to obtain a radiation image with excellent diagnostic performance, It is desirable to teach such signal processing. Desirable signal processing to be used in the present invention includes JP-A-55-87970 and JP-A-56-11.
No. 038, Japanese Patent Application No. 54-151398, No. 54-15
No. 1400, No. 54-151402, No. 54-168
Frequency processing disclosed in No. 937, etc., Mokai Sho 55-
No. 116339, No. 55'-116340, No. 55
Examples include gradation processing disclosed in Japanese Patent Application No.-88740.

In the first embodiment described above, sub-scanning for reading radiation images is performed by moving the excitation light irradiation system and the stimulation light reading system with respect to the fixed recording medium 3. However, on the contrary, the excitation light irradiation system and the photostimulation light reading system may be fixed in the image reading zone, and the sub-scanning may be performed by moving the recording medium.
In this embodiment, a sub-scanning method is used in which the recording medium is moved as shown in (2). In this second embodiment, as in the first embodiment, the recording medium is made of a radiation-transparent material. A recording medium 103 in which a stimulable phosphor 102 is laminated on a support 101 is used.
A radiation source 104 as in the embodiment. Excitation light source 1o6. Optical deflector 107. Photodetector 108. Light transmission means 109, erasing light source 110. Cleaning roller 1
1-1, but unlike the first embodiment, the excitation light source 106. The optical deflection is fixed and does not move. Both edges of the recording body 103 are Groove 1 in the center of two rails 112 extending in the direction
13, and the recording medium 103 is movable in the vertical direction in the figure along this rail 112. The recording medium 103 is then moved in the vertical direction in the figure by a linear moving device (not shown) such as a rack and pinion mechanism. After a transmitted radiation image of the subject 105 is recorded by the radiation source 104, excitation light is irradiated to read the radiation image. At this time, the main scanning is performed by the optical deflector 107 as in the first embodiment, but the sub-scanning is performed by moving the recording medium 103 from the bottom to the top in the figure by the linear movement device. It is done by letting When the recording body 103 is moved, the rotating cleaning roller 111 comes into contact with the recording body 103, and the recording body 103 is
is cleaned. After the image reading is completed, the i typeface 1
03 is returned downward, the erasing light source 110 is turned on, and the radiation drawing that has been completely read is erased.

In the second embodiment described above, the stimulable phosphor is moved for sub-scanning of image reading, but the movement of the stimulable phosphor is caused by moving the plate-shaped support. Of course, this type of moving mechanism can be formed more easily than a mechanism that transports sheet-like stimulable phosphors one by one.

In the two embodiments discussed above, the stimulable phosphor is laminated on a support made of a radiation-transparent material, and is placed on the opposite side of the support from the radiation source. , it is not absolutely necessary to form the recording body in this way. For example, when a stimulable fluorescent plate is laminated on a support made of a radiation-opaque material and placed facing a radiation source, the excitation light irradiation system and photostimulation light reading system are installed after the subject exits the surface of the recording medium. The system may be moved to the vicinity of the recording medium.

In addition, the recording state or recording pattern of the radiation image information stored and recorded on the stimulable phosphor sheet must be grasped prior to the reading operation, and the reading gain of the optical gravity reading means must be set and an appropriate recording scale factor determined. In order to obtain radiation images with excellent diagnostic performance, it is preferable to set the signal processing conditions as well, and for this purpose, the recording state of the radiation image information or the recording pattern should be lowered or excited before the reading operation. Reading with light energy (hereinafter referred to as “pre-reading”)
That's what it means. ), and then a method and apparatus for performing a reading operation (hereinafter referred to as ``main reading 1'') for obtaining a radiographic image for diagnosis, is patent I$(1), (21) for simultaneous use←
(3L (4) and (5)) (Applicant: Fuji Photo Film Co., Ltd., Agent: Masashi Yanagide (1 person)). In the present invention, the above-mentioned image reading method is also proposed. By providing 111J pre-reading reading sections having a similar configuration that operate before the image reading section, or by using the image reading section for both pre-reading and main reading,
The request to perform such pre-reading can be satisfied. Regarding the details of the device configuration, the one described in the above application specification is used, and as explained, only one recording medium is used repeatedly, so the quality of the reproduced image has deteriorated. In this case, it is sufficient to replace the recording medium in use with a new one, and quality control of the recording medium is extremely easy.

Since it is reused without being transported, there is no chance of damage to the stimulable phosphor during transport. It also makes it easier to manage your body. Since the structure is simple, it is easy to design and manufacture (the device can be formed into a small and light lid. Therefore, the device of the present invention is particularly suitable for being carried on a bus or the like and used on the move. Yes, its practical value is extremely high.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the first embodiment of the present invention, and Fig. 2 is a schematic diagram showing the second embodiment of the present invention. 3, 1
03...Word 1 record 4.104...Radiation source 5,
105... Subject 6, 106... Excitation light source 7,
107... Optical deflector 8.108... Optical detector/
10,110... Erasing light source (spontaneous) T-Continuation correction, Gin Showa 56f12J124 Dear Commissioner of the Patent Office 1 Table of cases 1982 Patent Application No. 165123 2 Name of invention Relationship with the case Patent applicant 4 , Agent 5, No date of amendment order 6 Number of inventions increased by amendment None 7,
Subject of amendment Details ^ , + ・- 9, Attached documents Type engraving details ^
1. Draw (Spontaneous 5 Procedural Amendments December 24, 1981 Mr. Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 165123 2. Name of the invention Radiographic image information recording/reading device 3. Person making the amendment Case and 0 related Patent applicant 4 No agent 6 Number of inventions increased by amendment N/A 7 Target of amendment ``Detailed explanation of the invention, 1st part 8, Contents of amendment, page 9, line 13 of the specification'' “Unexamined Japanese Patent Publication No. 55-12492” was changed to “Unexamined Japanese Patent Application No. 55-124
29 'I; - Corrected. ′

Claims (1)

[Scope of Claims] 1) A recording medium in which a stimulable phosphor that accumulates radiation energy is laminated on a plate-shaped support, and a subject is irradiated with radiation to the stimulable phosphor through this recording medium. An image recording unit that accumulates and records a transmitted radiation image of a subject on the stimulable phosphor, is arranged near the recording body, and scans the stimulable phosphor on which the radiographic image is accumulated and recorded. an image reading section having a photoelectric reading means for emitting excitation light to obtain an image signal, and prior to image recording on the stimulable phosphor after the image reading is performed in the image reading section; A radiation image information recording/reading device comprising an erasing means for emitting residual radiation energy on the stimulable phosphor. 2) The recording body is made of a support made of a radiation transparent material and is fixed to the image reading unit, and the image ae recording unit records an image on the recording body from one side of the recording body. (The radiation image information recording/reading device 3 according to claim 1, wherein the image reading section is formed to read the image from the other side of the recording body.) The radiation image information Ml according to claim 1, wherein the recording body is formed to move relative to the image reading unit for excitation light scanning.
l Nail reader.