JPH0358099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention causes radiation image information to be stimulated to emit light from a stimulable phosphor sheet by irradiating the stimulable phosphor sheet storing radiation image information with excitation light, The present invention relates to a radiation image information reading device that photoelectrically reads the obtained stimulated luminescence light using a photodetector.

Certain types of fluorophores are exposed to radiation (X-rays, α-rays, β-rays,
When irradiated with γ-rays, ultraviolet rays, etc., a part of this radiation energy is accumulated in the phosphor, and when this phosphor is irradiated with excitation light such as visible light, the phosphor increases depending on the accumulated energy. is known to exhibit stimulated luminescence, and phosphors exhibiting this property are called stimulable phosphors.

Using this stimulable phosphor, radiation image information of the human body, etc. is recorded once on the stimulable phosphor provided on the sheet, and this phosphor sheet is scanned with excitation light such as a laser beam. Generating stimulated luminescence light and photoelectrically reading out the obtained stimulated luminescence light to obtain an image signal,
The applicant has already proposed a radiation image recording and reading method in which the image signal is output as a visible image to a recording material such as a photographic light-sensitive material, CRT, etc. (JP-A-55-12429, JP-A No. 56-11395, etc.) This method is extremely capable of recording images over an extremely wide radiation exposure range compared to conventional radiographic systems that use silver halide photography. It has practical advantages. In other words, in stimulable phosphors, it is recognized that the amount of emitted light that is stimulated and emitted by excitation after accumulation is proportional to the amount of radiation exposure over an extremely wide range. Even if the amount of radiation exposure varies considerably depending on the photographing conditions, the amount of light emitted is read by the photoelectric conversion means by setting the reading gain to an appropriate value and converted into an electrical signal, and this electrical signal is used to perform photographic exposure. A radiation image that is not affected by fluctuations in radiation exposure can be obtained by outputting it as a visible image on a recording material such as a recording material or a display device such as a CRT.

In addition, according to this system, the radiation image information accumulated and recorded in the stimulable phosphor is converted into an electrical signal, then subjected to appropriate signal processing, and this electrical signal is used to produce recording materials such as photographic light-sensitive materials, CRTs, etc. By outputting the image as a visible image on a display device, a very large effect can be obtained in that a radiation image with excellent suitability for observation and interpretation (diagnosis) can be obtained.

In this way, in a radiation imaging system using a stimulable phosphor, the reading gain can be set to an appropriate value to photoelectrically convert the stimulated luminescence light and output it as a visible image. tube voltage or
Fluctuations in radiation exposure due to fluctuations in MAS values, variations in the sensitivity of stimulable phosphors, variations in sensitivity of photodetectors, changes in exposure due to subject conditions, or differences in radiation transmittance depending on the subject, etc. Even if the energy accumulated in the stimulable phosphor differs depending on the cause, and even if the amount of radiation exposure is reduced, it is possible to obtain radiographic images that are not affected by fluctuations in these factors. In addition, by first converting the stimulated luminescence light into an electrical signal and applying appropriate signal processing to this electrical signal, it is possible to obtain radiographic images suitable for diagnostic areas such as the chest and heart, improving the suitability for observation and interpretation. It becomes possible to do so.

However, in order to eliminate the influence of such fluctuations in imaging conditions or to obtain radiographic images that are suitable for observation and interpretation, it is necessary to change the recording state of the radiographic image information accumulated and recorded on the stimulable phosphor sheet, or the chest and abdomen. Visual images for observation and interpretation of recorded patterns (hereinafter referred to collectively as "accumulated recorded information") determined by the body parts of the subject, imaging methods such as simple contrast angiography, etc. It is essential to understand the information before outputting it, and to adjust the reading gain to an appropriate value or perform appropriate signal processing based on the accumulated recorded information thus obtained.

Furthermore, in order to obtain radiographic images that are highly suitable for observation and interpretation, it is necessary to determine the recording scale factor so that the resolution is optimized according to the contrast of the recorded pattern.

A method disclosed in Japanese Patent Laid-Open No. 55-50180 is known as a method of grasping accumulated recorded information of radiation image information prior to outputting a visible image.
This method is based on the knowledge that when the stimulable phosphor sheet is irradiated with radiation, the amount of instantaneous light emitted from the stimulable phosphor sheet is proportional to the amount of energy stored and recorded in the stimulable phosphor sheet. Based on this, by detecting this instantaneous emitted light, the accumulated recorded information of radiation image information is grasped, and based on this information, appropriate signal processing is performed to obtain a radiation image with excellent suitability for observation and interpretation. It is. According to this method, it is possible to adjust the reading gain to an appropriate value, to select an appropriate recording scale factor, or to perform appropriate signal processing, thereby eliminating the influence of fluctuations in imaging conditions. Alternatively, it is possible to obtain a radiation image that is highly suitable for observation and interpretation, but since the radiation irradiation section and the radiation image information reading section are usually located apart, a signal transmission system must be constructed between them. However, the device has to be complicated, and there is an unavoidable increase in cost.

Also, as disclosed in Japanese Patent Application Laid-open No. 55-116340,
A non-storage phosphor is provided near the stimulable phosphor sheet, and a photodetector detects the light emitted by the non-storage phosphor when recording radiation image information, and the light is stored and recorded in the stimulable phosphor. A method of estimating the recording state or recording pattern of the radiographic image information that has been recorded may be considered, but this method has the drawbacks of the method disclosed in JP-A No. 55-50180 and the stimulable phosphor itself. Since it is not used as a detection means, it can only indirectly infer the accumulated recorded information of image information accumulated and recorded in the stimulable phosphor.
The drawback was that the reliability of the information obtained in this way was low.

The present invention provides a device that can easily and accurately detect radiographic image information accumulated and recorded in a stimulable phosphor prior to a reading operation to obtain a visible image for observation and interpretation. The purpose is to

Another object of the present invention is to easily and accurately detect accumulated radiation image information stored in a stimulable phosphor prior to a reading operation to obtain a visible image for observation and interpretation. The object of the present invention is to provide an apparatus that can reproduce radiographic images with excellent diagnostic performance based on this information.

As a result of extensive research to achieve this objective, the present inventor has determined that the energy of the excitation light to be irradiated during the reading operation (hereinafter referred to as "reading") to obtain a visible image for observation and interpretation. A reading operation (hereinafter referred to as "pre-reading") for grasping the accumulated recording information of radiographic image information stored in the stimulable phosphor in advance prior to the actual reading using low-energy excitation light. When the radiographic image information is stored and recorded, the actual reading is performed, and the reading gain is appropriately adjusted based on the pre-read information, or appropriate signal processing is performed, changes in the imaging conditions are detected. It has been found that radiographic images that are free from the influence of radiation or have excellent suitability for observation and interpretation can be obtained, and that the above object is achieved. Even if one selects a stimulable phosphor that is considered to have the highest sensitivity at present, the amount of stimulated luminescence emitted by the stimulable phosphor upon excitation light irradiation is extremely weak, so it is important to Until now, it was considered an essential requirement for this system to detect the amount of light with a photodetector. In light of this, it is nothing short of absurd to intentionally dissipate the radiation energy stored and recorded in the stimulable phosphor by reading in advance before reading the book, and the above findings are extremely surprising.

The present invention is based on such knowledge, and includes an excitation light irradiation means, a transport means for a stimulable phosphor sheet, and a photodetection means for photoelectrically reading the stimulated luminescent light from the stimulable phosphor sheet. In the image information reading device, the means for transporting the stimulable phosphor sheet transfers the same stimulable phosphor sheet so that pre-reading and subsequent main reading are performed on one stimulable phosphor sheet. It is formed so that it can be sent to the excitation light irradiation position twice, and the energy of the excitation light at the time of looking ahead is
This is characterized by the provision of an adjustment means that can be made smaller than that used during actual reading.

Another radiation image information reading device of the present invention is
In a radiographic image information reading device including an excitation light irradiation means, a stimulable phosphor sheet transport means, and a light detection means, the stimulable phosphor sheet transport means is formed in the same manner as described above, and the stimulable phosphor sheet transport means is formed in the same manner as described above. In addition to the adjustment means, an output device for outputting the accumulated record information obtained by the above-mentioned pre-reading and an input device for inputting the reading conditions and/or image processing conditions for the above-mentioned main reading are further provided. This is a characteristic feature.

In the present invention, the energy of excitation light refers to the effective energy of excitation light received per unit area of the stimulable phosphor sheet.

In the present invention, it is sufficient that the energy of the excitation light to be applied to the stimulable phosphor during pre-reading is lower than the energy of the excitation light during main reading. The closer the ratio of the excitation light energy of pre-reading to that of main reading is to 1, the smaller the amount of radiation energy remaining and accumulated during main reading will be.If this ratio is less than 1, set the value of the reading gain appropriately. It has been found that by adjusting this, radiographic images suitable for observation and interpretation can be obtained. However, in order to obtain radiographic images that are highly suitable for observation and interpretation, it is necessary to use the accumulated recording information of the radiographic image stored in the stimulable phosphor through pre-reading to select the reading conditions or optimal image processing conditions. As long as it can be grasped to a sufficient degree for use, in other words, as long as the stimulated luminescence light emitted from the stimulable phosphor can be detected sufficiently in the above sense, the ratio of the energy of the excitation light in the pre-reading and the main reading is small. It is more desirable that it be less than 50%, preferably less than 10%, and more preferably less than 3%. The lower limit of this ratio is determined by the accuracy of the pre-read stimulated luminescence light detection system.

In the present invention, the adjustment means for making the energy of the excitation light in pre-reading smaller than the energy for main reading includes means for reducing the output of the laser light source;
Means for increasing the beam diameter of the laser beam, means for increasing the scanning speed of the laser beam, means for increasing the transport speed of the stimulable phosphor sheet, and other known means can be used.

In the present invention, it is desirable that the pre-reading be performed within one hour before the main reading. The radiation energy stored and recorded in the stimulable phosphor has a characteristic of fading over time. Therefore, in order to effectively use the recorded information obtained by pre-reading for main reading, It is desirable to minimize the time it takes to read the book. However, according to research conducted by the present inventors, the attenuation of the radiation energy stored and recorded in the stimulable phosphor is greatest immediately after recording radiation image information on the stimulable phosphor, and decreases approximately 1 hour after recording. It is recognized that 10% of radiation energy is lost due to attenuation, but the rate of attenuation decreases thereafter, and on the other hand, when the difference between the amount of accumulated radiation energy at the time of pre-reading and that at the time of main reading is 10% or less. teeth,
The accumulated record information obtained by pre-reading is used to detect the accumulated record information of the radiation image information accumulated and recorded in the stimulable phosphor, and this is used to set the reading conditions for the main reading or to perform signal processing after reading. It has been found that radiographic images with sufficient suitability for observation and interpretation can be obtained even when the above methods are used. Therefore, if the time interval between pre-reading and main reading is set to 1 hour or less, the difference in accumulated amount will always be 10% or less, and it is guaranteed that radiological images with sufficient suitability for observation and interpretation for practical purposes will be obtained. ,preferable.

According to the present invention, since it is possible to know in advance the recording state of radiographic image information stored and recorded in a stimulable phosphor, the recorded information can be read without using a reading system having a particularly wide dynamic range. By appropriately adjusting the reading gain based on the above, it is possible to obtain radiographic images that are always suitable for observation and interpretation even when the imaging conditions vary.

Furthermore, according to the present invention, it is possible to know in advance the recording pattern of radiation image information stored and recorded in the stimulable phosphor, so that signal processing according to the recording pattern is applied to the electrical signal after reading. By applying this method or by optimizing the recording scale factor, it becomes possible to obtain radiographic images with excellent suitability for observation and interpretation.

Furthermore, according to the present invention, it is possible to know in advance the recording pattern of the radiographic image information stored and recorded in the stimulable phosphor, so it is possible to omit the actual reading of parts where the recording pattern does not exist. , it becomes possible to shorten the reading time.

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, Japanese Patent Application Publication No. 1983-
As disclosed in Publication No. 12492, the excitation light wavelength is 600 to 700 nm, and the stimulated emission light wavelength is 300 to 700 nm.
It is desirable to set the wavelength to 500 nm.

As described above, examples of stimulable phosphors that emit stimulated luminescent light of 300 to 500 nm and can be preferably used in the present invention include rare earth element-activated alkaline earth metal fluorohalide phosphors [specifically, ,
(Ba _1-xy , Mg _x , Ca _y )FX described in JP-A-55-12143: aEu ²⁺ (However,
and Br, x and y are 0<x+y0.6 and xy≠0, and a
is 10 ^-6 a5 × 10 ^-2 ), - Japanese Patent Application Publication No. 1983-
Described in Publication No. 12145 (Ba _1-x , M〓 _x )
FX: yA (However, M〓 is Mg, Ca, Sr, Zn and Cd
at least one of X is Cl, Br and I
At least one of A is Eu, Tb, Ce,
At least one of Tm, Dy, Pr, Ho, Nd, Yb and Er, x is 0x0.6, y is 0y
ZnS: Cu, Pb, BaO x Al ₂ O ₃ : Eu
(however, 0.8x10) and M〓O・xSiO ₂ :A (however, M〓 is Mg, Ca, Sr, Zn, Cd or Ba,
A is Ce, Tb, Eu, Tm, Pb, Tl, Bi or Mn
and x is 0.5x2.5); and LnOX:xA described in JP-A-55-12144 (where Ln is at least one of La, Y, Gd, and Lu, and X is Cl and at least one of Br
1, A is at least one of Ce and Tb;
x is 0<x<0.1); Among these, rare earth element-activated alkaline earth metal fluorohalide phosphors are preferred, and among these, barium fluorohalides shown as specific examples are particularly preferred because of their excellent stimulable luminescence.

Furthermore, barium fluorohalide phosphors doped with metal fluorides as disclosed in JP-A-56-2385 and JP-A-56-2386, or those disclosed in JP-A-56-74,175. As disclosed, the addition of at least one of metal chlorides, metal bromides, and metal iodides is preferable because stimulated luminescence is further improved.

Further, as disclosed in JP-A-55-163500, when the phosphor layer of a stimulable phosphor plate prepared using the above-mentioned stimulable phosphor is colored with a pigment or dye, This is preferable because the sharpness of the finally obtained image is improved.

The signal processing used in the present invention includes:
JP-A-55-87970, JP-A-56-11038, JP-A-56-
No. 75137, No. 56-75139, No. 56-75141, No. 56
−Frequency processing disclosed in JP-A No. 104645, etc., JP-A No. 55-116339, JP-A No. 55-116340, JP-A No. 55-88740
For example, the gradation processing disclosed in No.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a radiation image information reading device showing an embodiment of the present invention. Radiation such as X-rays is irradiated through a subject such as a human body, and a stimulable phosphor sheet 1 on which radiation image information is stored and recorded is transferred to a reading device shown in FIG. In the reading device, the transferred device is first read in advance. A laser beam 3 emitted from a laser light source 2 passes through a beam expander 4, and after the beam diameter of the laser beam is strictly adjusted in advance, it passes through an ND filter 5, a prism 6, and a concave lens 7, and then the laser beam is The intensity of the light 3 is reduced and the beam diameter is expanded. Furthermore, the light is one-dimensionally deflected and incident on the stimulable phosphor sheet 1 by a light deflector 8 such as a galvanometer mirror and a plane reflector 9. An fθ lens 10 is disposed between the optical deflector 8 and the plane reflecting mirror 9, so that even when the laser beam 3 is scanned on the phosphor sheet 1, the beam diameter is always uniform. Here, the laser light source 2 is selected so that the wavelength range of the laser light 3 does not overlap with the wavelength range of the stimulated luminescent light from the stimulable phosphor sheet 1. On the other hand, the stimulable phosphor sheet 1 is conveyed in the direction of the arrow 11 for sub-scanning, and as a result, the entire surface of the phosphor sheet 1 is irradiated with laser light. Here, the power of the laser light source 2, the beam diameter of the laser light 3, the scanning speed of the laser light 3, and the transport speed of the phosphor sheet 1 are selected so that the energy of the laser light 3 for pre-reading is smaller than that for main reading. has been done. When the laser beam 3 is irradiated in this way, the stimulable phosphor sheet 1 emits stimulated luminescence light whose amount is proportional to the radiation energy stored and recorded, and this luminescent light is transmitted to the pre-reading light guiding sheet 12. incident. The light guide sheet 12 has a linear incident surface and is placed adjacent to and opposite to the scanning line on the stimulable phosphor sheet 1, and has a smooth exit surface to allow light such as photoprints to pass through the light guide sheet 12. Detector 13
The sensor is placed in close contact with the light-receiving surface of the sensor. This light guiding sheet 12 is made by processing a transparent thermoplastic resin sheet such as acrylic resin, and is configured so that the light incident from the incident surface is transmitted to the exit surface while being totally reflected inside. The stimulated luminescent light from the stimulable phosphor sheet 1 is transmitted through the light guiding sheet 12.
The photodetector 13 exits from the exit surface.
The light is received by. Preferred shapes, materials, etc. of the light-guiding sheet are disclosed in Japanese Patent Laid-Open Nos. 55-87970 and 56-11397.

A filter is attached to the light-receiving surface of the photodetector 13, which transmits only light in the wavelength range of the stimulated luminescence light and cuts out light in the wavelength range of the excitation light, and detects only the stimulated luminescence light. It's getting wet. Photodetector 1
The output of 3 is amplified by the look-ahead amplifier 15,
The image is output as a visible image on an output device 16 such as a CRT. By visually observing this visible image, you can check the accumulated record information of radiation image information in advance before reading the book.
In other words, it is possible to grasp the recording state or recording pattern, and by manually operating the input device 23 connected to the control circuit 17 based on this accumulated recording information, the amplification factor setting value a during main reading can be determined. , recording scale factor setting value b, and reproduction image processing condition setting value c are output.
Furthermore, by observing the visible image output on the output device 16 such as a CRT, the relative position of the stimulable phosphor sheet 1 in the radiation image reading device can be found, allowing for highly accurate positioning. When using a superimposition method or a subtract method that requires alignment, by providing a position control means, the relative position of the stimulable phosphor sheet 1 can be determined with high accuracy before reading the actual image. .

After pre-reading, the stimulable phosphor sheet 1 is returned to the reading start position 18 by a sub-scanning motor (not shown), and then main reading is started. In the main reading, the laser light 3 is emitted from the laser light source 2 as in the pre-reading, but in the case of main reading, the ND filter 5 and the prism 6 are used.
Since the concave lens 7 is moved in the direction of the arrow 19 so as to be out of the optical path, the laser beam 3 is caused to directly reach the optical deflector 8 such as a galvano mirror after the beam diameter is precisely adjusted by the beam expander 4. The light is incident on the stimulable phosphor sheet 1 through the plane reflecting mirror 9 while being one-dimensionally deflected. Here, an fθ lens 10 is provided between the optical deflector 8 and the plane reflecting mirror 9, so that even when the laser beam 3 is scanned over the phosphor sheet 1, a uniform beam diameter is maintained. It is made to be wet. On the other hand, the stimulable phosphor sheet 1 is conveyed at a constant speed in the direction of the arrow 11 for sub-scanning, and as a result, the entire surface of the stimulable phosphor sheet 1 is irradiated with the laser beam 3. The stimulable phosphor sheet 1 irradiated with the laser beam 3 emits stimulated luminescent light corresponding to the energy level of the radiographic image information stored and recorded, and this stimulated luminescent light is generated in exactly the same way as in the case of pre-reading. and enters the light guide sheet 12,
The light is transmitted through the interior and detected by the photodetector 13. The output of the photodetector 13 is the switch 1
4, the signal is amplified into an electrical signal at an appropriate level by the actual reading amplifier 20 whose sensitivity is set based on the amplification factor setting value a. The amplified electrical signal is A/D
The signal is inputted to the converter 21, converted into a digital signal with a scale factor suitable for the signal fluctuation range based on the recorded scale factor setting value b, and inputted to the signal processing circuit 22. In the signal processing circuit 22, signal processing is performed based on the reproduction image processing condition set value c so as to obtain a radiation image excellent in suitability for observation and interpretation, and the radiation image is transmitted to a reproduction device that outputs the radiation image as a visible image.

In the reproduction device, a radiation image is reproduced based on the image signal that has undergone signal processing by the signal processing circuit 22. Reproduction methods include recording by scanning a photosensitive material with a laser beam, displaying it electronically on a CRT, etc., recording the radiation image displayed on a CRT, etc. on a video printer, etc., and using heat rays. Various recording methods can be used, such as a method of recording on a heat-sensitive recording material.

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

For example, although pre-reading is performed over the entire surface of the stimulable phosphor sheet, it is not necessarily necessary to perform over the entire surface of the phosphor sheet. Usually, X
In the case of a line photograph, there is no image information to be observed and interpreted at the periphery of the phosphor sheet, so for example, for a few centimeters of the periphery, pre-reading can be omitted, and the necessary radiographic image information can be omitted in advance. If the storage recording area is known, it is sufficient to pre-read only that area, and by pre-reading only the effective area, the reading time can be shortened.

In addition, the method of transporting the stimulable phosphor sheet for main reading after pre-reading is not limited to the method of reversing the sub-scanning motor to return the stimulable phosphor sheet to the reading starting position, but also the method of switching the drive system. Alternatively, after pre-reading is completed, the stimulable phosphor can be reversed by setting the plane image processing conditions and reading conditions, reversing the sub-scanning motor, or switching the drive system. You may also read a book while moving it in the same direction.

Furthermore, in the embodiment described above, the energy of the excitation light for pre-reading is made smaller than that for main reading by using an ND film and a concave lens, but it is also possible to simply expand the beam diameter with a concave lens without using an ND filter. Alternatively, a beam expander may be used instead of a concave lens to expand the beam diameter. Furthermore, it is also possible to prepare a laser light source with low power and use means for switching the path of the optical system.

Furthermore, instead of using a single light-guiding sheet as in the embodiment described above, two light-guiding sheets may be provided facing each other with a scanning line in between. A reflecting mirror may also be used as disclosed in the publication.

Furthermore, the laser light source as the excitation light source can be replaced with an LED array 25 having a wavelength range different from that of the stimulated luminescent light, as shown in FIG. In this case, an optical polarizer such as a galvano mirror can be omitted. In this embodiment, LED
A condensing lens 26 is provided to better condense the light emitted from the array 25.

In addition, the photodetector does not have to be a single one with a light-guiding sheet; instead, it can be a linear sensor in which multiple photodetectors or phototransistors are arranged in a straight line in the main scanning direction, as shown in Figure 2. It is also possible to use

Furthermore, it is also possible to uniformly expose the entire surface of the stimulable phosphor sheet and use a photodetector capable of two-dimensionally capturing the light, such as a television camera.

In addition, the reading gain can be adjusted by changing the amplification factor of the amplifier of the photodetector as explained in the above embodiment, or by changing the voltage applied to the photomultiply when a photomultiplier is used as the photodetector. By doing so, the gain of the photodetector may be directly changed. This has the advantage that only the signal is amplified and the noise is not amplified.

Furthermore, in the embodiment, the conditions for main reading are set by manually operating the control circuit based on the visible image obtained by pre-reading.
It may be possible to have a control system so that the visible image displayed is the same as the visible image actually observed and interpreted, and in this way the control circuit can more easily perform appropriate processing. You can set various conditions.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a radiation image information reading device showing an embodiment of the present invention, and FIG. 2 is a schematic diagram of a radiation image information reading device showing another embodiment of the invention. DESCRIPTION OF SYMBOLS 1...Storage phosphor sheet, 2...Laser light source, 3...Laser light, 4...Beam expander, 5...ND filter, 6...Prism, 7...
... Concave lens, 8 ... Light deflector, 9 ... Plane reflecting mirror, 10 ... fθ lens, 11 ... Transport direction, 12
...Light guiding sheet, 13... Photodetector, 14...
Switch, 15... Amplifier for pre-reading, 16... Output device, 17... Control circuit, 18... Reading start position, 20... Amplifier for main reading, 21... A/D converter, 22... Signal processing circuit , 23... Input device, 25... LED Array, 26... Condenser lens,
27...Linear sensor.

Claims (1)

[Scope of Claims] 1. Excitation light irradiation means for irradiating excitation light onto a stimulable phosphor sheet on which radiation image information is stored and recorded; means for transporting the stimulable phosphor sheet; In a radiation image information reading device including a photodetecting means for photoelectrically reading stimulated luminescence light carrying radiation image information emitted from a stimulable phosphor sheet, The same stimulable phosphor sheet is formed to be sent to the irradiation position of the excitation light twice so that the reading process of pre-reading and subsequent main reading is performed twice; A radiation image information reading device characterized by comprising an adjusting means capable of making the energy of the excitation light at the time of main reading smaller than the energy of the excitation light at the time of main reading. 2 Excitation light irradiation means for irradiating excitation light onto a stimulable phosphor sheet on which radiation image information is stored and recorded; means for transporting the stimulable phosphor sheet; In a radiation image information reading device including a photodetecting means for photoelectrically reading stimulated luminescence light carrying emitted radiation image information, the transport means performs pre-reading and subsequent main reading for one stimulable phosphor sheet. The same stimulable phosphor sheet is formed to be sent to the excitation light irradiation position twice so that the reading process is performed twice, and the energy of the excitation light at the time of pre-reading is An adjusting means that can make the energy of the excitation light smaller than the energy of the excitation light during the main reading, an output device that outputs the accumulated record information obtained by the pre-reading, and an input device that inputs the reading conditions and/or image processing conditions during the main reading. A radiation image information reading device comprising: