JPH04314432A - Method and apparatus for photographing and reading radiation image - Google Patents

Abstract

PURPOSE:To eliminate rephotographing by enabling the checking of an image obtained by pre-photographing to always obtain a desired radiation image. CONSTITUTION:A preliminary photographing is performed by a radiation with a limited dose, less than several fractions of a radiation dose to be used for the ordinary main photographing and a computer system 52 alters photographing conditions of the preliminary photographing, reading conditions and image processing conditions as required to determine conditions of the main photographing. A photographing means 2, a reading means 3 and an image processing means 4 are controlled based on the conditions determined to perform the main photographing and a visible image of the radiation image is obtained with excellent observability. A keyboard 53 is provided to correct the photographing conditions, reading conditions and image processing conditions by an manual operation based on the radiation image obtained by the preliminary photographing.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention captures a radiation image of a subject on a recording medium, reads the radiation image from this recording medium to obtain an image signal, performs image processing on this image signal, and then performs image processing. The present invention relates to a radiographic imaging and reading method and apparatus for reproducing a visible image based on a given image signal.

0002

[Prior art] A radiation image of a subject is recorded on a recording medium,
BACKGROUND ART It is practiced in various fields to obtain an image signal by reading a radiation image recorded on a recording medium, perform appropriate image processing on this image signal, and then reproduce and record the image. For example, recording an X-ray image using a low gamma X-ray film designed to be compatible with subsequent image processing;
By reading the X-ray image from the film on which it was recorded, converting it into an electrical signal, performing image processing on this electrical signal (image signal), and then reproducing it as a visible image in a photocopy, etc. Efforts have been made to obtain reproduced images with good image quality performance such as contrast, sharpness, and graininess (see Japanese Patent Publication No. 5193/1983).

[0003] Also, the applicant of the present application has reported that radiation (X-rays, α
When irradiated with rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc., a part of this radiation energy is accumulated, and then when excited light such as visible light is irradiated, the accumulation exhibits stimulated luminescence depending on the accumulated energy. Using stimulable phosphor (photostimulable phosphor),
Radiographic image information of a subject such as a human body is recorded on a sheet of stimulable phosphor, and this stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescence. A radiation image recording and reproducing system has already been proposed which photoelectrically reads the exhaustion light to obtain an image signal and outputs the radiation image of the subject as a visible image on a recording material such as a photographic light-sensitive material, a CRT, etc. based on this image signal. (Unexamined Japanese Patent Publication No. 5
No. 5-12429, No. 56-11395, No. 55-1
No. 63472, No. 56-104645, No. 55-
116340 etc. ) This system has the practical advantage of being able to record images over a much wider range of radiation exposure compared to conventional radiographic systems using silver halide photography. 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, and therefore the amount of radiation exposure varies depending on various imaging conditions. Even if the value varies considerably, the amount of stimulated luminescence light emitted from the stimulable phosphor sheet is read by the photoelectric conversion means by setting the reading gain to an appropriate value and converted into an electrical signal. By outputting a radiation image as a visible image to a recording material such as a photographic material or a display device such as a CRT using the method, it is possible to obtain a radiation image that is not affected by fluctuations in the amount of radiation exposure.

[0004] In the above system, the stimulable phosphor sheet is previously exposed to a low-level light beam before reading it under optimal reading conditions depending on the dose of radiation applied to the stimulable phosphor sheet to obtain an image signal. Scanning is performed to read the outline of the radiation image recorded on this sheet, and the pre-read image signal obtained by this pre-reading is analyzed.Then, the sheet is irradiated with a high-level light beam and scanned. There is also a system configured to perform a main reading in which an image signal is obtained by reading under the optimum reading conditions for a radiation image.

[0005] Here, the reading condition is a general term for various conditions that affect the relationship between the amount of stimulated luminescence light and the output of the reading device during reading, such as the reading gain that determines the input/output relationship, It means the scale factor or the power of excitation light in reading.

[0006] The high level/low level of the light beam refers to the amount of energy of the light beam irradiated per unit area of the sheet, or the energy of the stimulated luminescence light emitted from the sheet, respectively. If the light beam depends on the wavelength of the light beam (has a wavelength sensitivity distribution), the weighting energy after weighting the energy of the light beam irradiated per unit area of the sheet by the wavelength sensitivity. Okay, methods of changing the level of the light beam include using light beams of different wavelengths, changing the intensity of the light beam itself emitted from a laser light source, etc.
There are various known methods such as changing the intensity of the light beam by inserting or removing an ND filter or the like on the optical path of the light beam, changing the scanning density by changing the beam diameter of the light beam, and changing the scanning speed. can be used.

[0007] In addition, regardless of whether the system performs pre-reading or the system does not perform pre-reading, the obtained image signal (including the pre-read image signal) is analyzed and the optimal image is determined when performing image processing on the image signal. Some systems are designed to determine processing conditions. The term "image processing conditions" as used herein is a general term for various conditions when performing processing on an image signal that affects the gradation, sensitivity, etc. of a reproduced image based on the image signal. The method of determining the optimal image processing conditions based on this image signal is not limited to systems using stimulable phosphor sheets; for example, image signals are obtained from radiation images recorded on a recording sheet such as a conventional X-ray film. It is also applied to the system.

[0008]

[Problems to be Solved by the Invention] The above system is often used for medical diagnosis of the human body, etc., regardless of whether it is a system that performs pre-reading or a system that does not perform pre-reading. It is required to be able to output visible images with excellent interpretation aptitude. For this reason, the optimal reading conditions or image processing conditions are determined for the photographed subject, and the optimal radiographic image is played back, but until the radiographic image is played back, the content of the image must be confirmed. If this is not possible and the desired radiation image cannot be obtained, it is necessary to perform the imaging again, which is undesirable because the subject such as the human body is exposed to radiation again.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a radiographic image capturing and reading method and apparatus, which allows confirmation of the image during radiography, allows a desired radiographic image to be obtained at all times, and eliminates the need to perform radiography again. It is something.

0010

[Means for Solving the Problems] The radiographic image capturing and reading method according to the present invention includes: ◆ irradiating a subject with radiation, capturing a radiographic image of the subject on a recording body, reading the radiographic image from this recording body, and creating an image. In a radiation imaging reading method that obtains a signal, performs image processing on this image signal, and then reproduces a visible image based on the image signal subjected to image processing, ◆ a radiation image of the subject is recorded on the recording medium; Prior to the actual imaging, a preliminary imaging is performed in which the subject is imaged on the recording body using a small dose of radiation, which is about one-tenth to one-tenth of the radiation dose normally used for the actual imaging. , ◆ Obtain an image signal by reading the radiation image obtained by the previous imaging based on temporary reading conditions, and perform image processing on the image signal based on temporary image processing conditions,
Photographing conditions for reproducing a visible image based on the image signal subjected to the image processing and performing the actual photographing based on the visible image, and conditions for reading the image signal from the recording medium on which the actual photographing has been performed. Determine reading conditions and image processing conditions for performing image processing on the image signal obtained by the main imaging, ◆ perform the main imaging based on the imaging conditions, and ◆ perform the main imaging based on the reading conditions. Reads the image signal from the photographed recording medium,
Image processing is performed on the image signal obtained by the main imaging based on the image processing conditions, and a visible image is reproduced based on the image signal obtained by the main imaging which has been subjected to the image processing. That is.

[0011] Here, "determining" the photographing conditions, reading conditions, and image processing conditions for the main photographing based on the visible image obtained by the previous photographing means that the photographing conditions, temporary reading conditions, and/or Alternatively, if the temporary image processing conditions are also suitable for each of the above conditions for the main shooting, each condition of the previous shooting can be used as is for the main shooting, and each of the conditions of the previous shooting can be changed based on the visible image obtained from the previous shooting. This includes making changes to the conditions as necessary, and setting new conditions for the actual shooting through calculations, etc. based on the visible image obtained from the previous shooting. .

[0012] The term "imaging conditions" as used herein refers to conditions necessary during imaging, such as the radiation dose during imaging and positioning for adjusting the position of the subject.

[0013] Also, one of the devices for carrying out the radiographic image capturing and reading method according to the present invention is a device that automatically determines the shooting conditions, reading conditions, and image processing conditions for the actual radiography, and includes: A radiation image of the subject is captured on a recording medium, the radiation image is read from this recording medium to obtain an image signal, this image signal is subjected to image processing, and then based on the image signal subjected to image processing, In a radiation image capturing/reading device that reproduces a visible image, ◆ main imaging in which the radiation image of the subject is captured on the recording medium, and a radiation dose of a fraction of the radiation dose normally used for the main imaging in advance to several tens of minutes. ◆ An imaging means that selects a radiation with a small dose of about 1, irradiates the subject with the radiation with a small dose and performs a pre-imaging to image the recording body; a reading means for reading a radiation image to obtain an image signal; ◆ an image processing means for performing image processing on the image signal; ◆ a reproduction means for reproducing a visible image based on the image signal subjected to the image processing; ◆Based on the visible image obtained from the previous radiography, the imaging conditions for the main radiography, the reading conditions for reading the radiation image obtained by the main radiography to obtain an image signal, and the information obtained from the main radiography are determined. The apparatus is characterized by comprising a condition determining means for determining image processing conditions for performing image processing on an image signal obtained by reading a radiographic image.

[0014] Here, the imaging conditions determined by one of the above-mentioned radiation image reading apparatuses refer to conditions that can be automatically determined by the imaging means among the necessary conditions at the time of imaging.
This does not include photographing conditions that cannot be determined automatically by the photographing means, such as when positioning is adjusted manually.

[0015] Another device for carrying out the radiographic image capturing and reading method according to the present invention is a device that determines the shooting conditions, reading conditions, and image processing conditions of the actual radiography by manual operation. The radiation image of the subject is captured on a recording medium, the radiation image is read from this recording medium to obtain an image signal, this image signal is subjected to image processing, and the image signal subjected to image processing is then processed. In a radiographic image capturing and reading device that reproduces a visible image based on an imaging means that selects radiation with a small dose of about 1/10, irradiates the subject with the radiation with the small dose and performs a pre-imaging to image the recording medium; ◆ An image processing means that performs image processing on the image signal; ◆ A reproduction means that reproduces a visible image based on the image signal subjected to the image processing. and ◆imaging conditions for the main imaging after reproducing a visible image from the radiation image obtained by the previous imaging, reading conditions for reading the radiation image obtained by the main imaging to obtain an image signal, and The present invention is characterized by comprising a condition correction means that makes it possible to correct image processing conditions when performing image processing on an image signal obtained by reading the radiation image obtained by the main imaging.

[0016] In the present invention, the radiation dose during the pre-imaging is approximately 1/10 to 1/10 of the radiation dose in the main imaging, but preferably 1/5 to 1/20 of the radiation in the main imaging. It is best to take pictures in advance depending on the amount.

[0017]

[Operations and Effects of the Invention] The radiographic image capturing and reading method according to the present invention is implemented for a period ranging from a fraction of the dose of radiation used during the actual imaging to several tens of minutes prior to the actual imaging in which the radiation image of the subject is recorded on the recording medium. Preliminary radiography is performed to record a radiographic image of the subject on a recording medium with a low radiation dose that has almost no effect on the human body, etc., and the radiographic image obtained from the preliminary radiography is used to determine the radiographic conditions for the main radiography and the actual Since the reading conditions for reading the image signal from the photographed recording medium and the image processing conditions for performing image processing on the image signal obtained from the actual radiography are determined, it is possible to check the radiation image during the radiography. It is possible to always obtain radiographic images with excellent positioning, radiation dose, density, contrast, image processing, etc. that are suitable for observation and interpretation, and there is no need to perform re-imaging in which the subject is exposed to the radiation from the original imaging again. can.

[0018]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of the radiographic image capturing and reading apparatus of the present invention, which includes an image capturing means, a reading means, an image processing means, and a system for transporting the stimulable phosphor sheet using the above-mentioned stimulable phosphor sheet. A built-in type of radiographic imaging in which a conveying means and an erasing means for erasing images recorded on a stimulable phosphor sheet are integrated into one device, and the stimulable phosphor sheet is recycled and reused. FIG. 1 is a diagram schematically showing a reading device.

The built-in type radiation image capturing/reading device 10 includes a photographing means 2 for photographing a radiation image of a subject 13.
and reading means 3 for obtaining an image signal S by reading the stimulable phosphor sheet 1 on which the radiation image of the subject 13 is recorded;
An image processing means 4 that performs image processing on the image signal S' obtained by the reading means 3, a reproduction means 5 that reproduces a visible image based on the image signal S'' that has been subjected to image processing, and The photographing conditions, reading conditions, and/or
or a computer system 52 that is a condition determining means for determining image processing conditions and is integrated with the reproducing means; and a conveying means (not shown) for conveying the stimulable phosphor sheet 1;
It is comprised of an erasing means (not shown) for erasing the radiation image recorded on the stimulable phosphor sheet 1.

In the imaging means 2, the radiation source 1 emits a small dose of radiation 12, which is a few to several tenths (preferably one-fifth to one-twentieth) of the normally used radiation.
Preliminary imaging is performed in which the transmitted radiation is emitted from the stimulable phosphor sheet 1 and is recorded on the stimulable phosphor sheet 1, which is a recording medium.

The stimulable phosphor sheet 1, which has been previously photographed, is conveyed to the reading means 3 by a conveying means (not shown), and is read at a higher speed and with a coarser sampling density than usual.

The method of reading the stimulable phosphor sheet 1 using the reading means 3 will be described below.

FIG. 2 is a perspective view showing an example of a radiation image reading device in the reading means 3 for reading radiation images recorded on the stimulable phosphor sheet 1.

The stimulable phosphor sheet 1, which has been previously photographed by the photographing means 2, is set at a predetermined position in the reading device 30. The set stimulable phosphor sheet 1 is conveyed (sub-scanning) in the direction of arrow Y by a sheet conveying means 32 such as an endless belt driven by a motor 31. On the other hand, the excitation light 34 emitted from the laser light source 33 is reflected and deflected by a rotating polygon mirror 36 that is driven by a motor 35 and rotates at high speed in the direction of the arrow Z. After passing through a focusing lens 37 such as an fθ lens, the excitation light 34 is directed by a mirror 38 into the optical path. The light beam enters the sheet 1 while changing the direction of the light beam and performs main scanning in the direction of arrow X, which is substantially perpendicular to the direction of sub-scanning (direction of arrow Y). Stimulated luminescence light 39 is emitted from the portion of the sheet 1 irradiated with this excitation light 34 in an amount corresponding to the radiographic image information stored and recorded, and this stimulated luminescence light 39 is collected by a condenser 40. The light is emitted and is photoelectrically detected by a photomultiplier (photomultiplier tube) 41 as a photodetector. The light collector 40 is made by molding a light-guiding material such as an acrylic plate, and has a linear incident end surface 40a extending along the main scanning line on the stimulable phosphor sheet 1. The light-receiving surface of the photomultiplier 41 is coupled to the annularly formed output end surface 40b. The stimulated luminescent light 39 that has entered the light condenser 40 from the incident end surface 40a is transmitted to the light condenser 40.
The photomultiplier 41 detects the amount of stimulated luminescent light 39 carrying the radiation image information. The analog output signal S output from the photomultiplier 41 is amplified by an amplifier 42, sampled at a predetermined recording scale factor by an A/D converter 43, and digitized to obtain an image signal S'. The recording scale factor for pre-shooting is set to sample at a coarser density than usual.

In addition, the reading conditions in this case, that is, the sensitivity Sk and latitude Gp when reading the stimulable phosphor sheet 1 are the reading conditions (tentative sensitivity) temporarily determined for reading the radiation image obtained by the previous imaging. Sk and the tentative latitude Gp).

Here, the latitude Gp corresponds to the light intensity ratio of the most intense stimulated luminescence light to the weakest stimulated luminescence light that is converted into an image signal during main reading, and the sensitivity Sk corresponds to a predetermined value. This is the photoelectric conversion rate that determines the level of image signal that is converted from the amount of stimulated luminescence light.

The digitized image signal S' obtained by the A/D converter 43 is then input to the image processing means 4, which reproduces and outputs the visible image of the radiation image obtained by the previous imaging. At this time, image processing is performed under temporary image processing conditions to provide a visible reconstructed image with excellent observation and interpretation suitability, depending on the diagnostic purpose.

The image signal S'' subjected to temporary image processing by the image processing means 4 is input to the reproduction means 5.

The reproducing means 5 includes a CRT display 51 for reproducing radiation images, and a computer system 5 which is a condition determining means and has a built-in CPU and internal memory.
2, and a keyboard 53 through which an operator inputs necessary information into the computer system 52.

[0031] In the reproducing means 5, the CRT display 5
1. Once a visible image of the radiation image obtained by the previous imaging is obtained, the computer system 52
determines the imaging conditions for the actual imaging, the reading conditions for reading the radiation image obtained in the actual imaging, and the image processing conditions for performing image processing on the image signal of the radiation image obtained in the actual imaging.

[0032] Here, the imaging conditions are conditions related to imaging, such as the radiation dose during the actual imaging. The radiation dose during this actual imaging is determined by the computer system 52 based on the sensitivity Sk of the provisional reading conditions mentioned above, and the radiation source 11 of the imaging means 2 is sent from the computer system 52 to the radiation source 11 of the imaging means 2 so as to irradiate the optimum radiation dose. Control is exercised. Furthermore, if the region of interest of the subject is not within the radiation image, the positioning is adjusted by moving the subject, etc.

Furthermore, the reading conditions correspond to the sensitivity Sk and latitude Gp when reading the radiographic image described above, and the image processing conditions correspond to the gradation, sensitivity, etc. of the reproduced image based on the image signal as described above. This is a general term for various conditions when applying processing that affects image signals to image signals.

In the computer system 52, it is determined how much correction should be made to the above-mentioned temporary reading conditions and image processing conditions, and the necessary amount of correction is made. , the reading conditions for reading the radiographic image obtained in the actual radiography and the image processing conditions for performing image processing on the image signal of the radiographic image obtained in the main radiography are determined, and the reading means 3 operates based on the reading conditions. , the image processing means 4 are controlled based on the image processing conditions.

[0035] In this way, the computer system 52
The above-mentioned temporary reading conditions and temporary image processing conditions are corrected, but if it is determined that optimal reading is possible with the temporary reading conditions and/or the optimal radiation is corrected with the temporary image processing conditions. If it is determined that an image can be obtained, the computer system 52 uses the temporary reading conditions and the temporary image processing conditions in the actual shooting, respectively, without making any corrections to the temporary reading conditions and/or the temporary image processing conditions. Determine the reading conditions when reading the obtained radiographic image and the image processing conditions when performing image processing on the image signal of the radiographic image obtained in the main imaging, and based on these reading conditions and/or image processing conditions. The reading means 3 and/or the image processing means 4 are controlled.

Once determined from the photographing conditions, reading conditions and image processing conditions, the photographing means 2 performs the main photographing of the subject 13 based on the determined photographing conditions, and the radiation image is deposited on the stimulable phosphor sheet 1'. Accumulated and recorded.

Furthermore, in the reading means 3, the voltage applied to the photomultiplier 41 and the amplification factor of the amplifier 42 are controlled based on the reading conditions determined in the same way as when reading a radiation image obtained by previous imaging. , the radiation image of the stimulable phosphor sheet 1' is read at a normal scale factor to obtain a digitized image signal SQ'. Next, image processing is performed on the image signal SQ' based on the image processing conditions determined in the image processing means 4, and the image signal SQ'' subjected to the image processing is inputted to the reproduction means 5 to produce an optimal radiation image. An image is obtained.

The stimulable phosphor sheets 1, 1' on which radiographic images have been recorded by the previous radiography and the main radiography are conveyed to an erasing means (not shown), the radiographic images are erased, and the sheets are reused.

In the above embodiment, a built-in type radiographic imaging and reading device is used, but the imaging means,
It goes without saying that the reading means, image processing means, etc. do not need to be configured together in one radiation image capturing/reading apparatus, and may be provided separately.

Further, in the above embodiment, the photographing conditions, reading conditions, and image processing conditions are set by the computer system 52.
However, the imaging conditions are determined from the visible image of the radiation image displayed on the CRT display 51.
A human determines the reading conditions and image processing conditions, makes corrections using the keyboard 53 if necessary, and changes the photographing conditions and
Reading conditions and image processing conditions may also be determined.

Further, in the above embodiment, the radiation image capturing and reading method according to the present invention uses a stimulable phosphor sheet to obtain a visible radiation image, but is not limited to the stimulable phosphor sheet. Of course, the image may be obtained by photographing the subject using a recording sheet on which an image is recorded, for example, an X-ray film.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a built-in type radiographic image capturing and reading device using a stimulable phosphor sheet as an example of the radiographic image capturing and reading device of the present invention.

[Fig. 2] A perspective view showing an example of a radiation image reading device that reads radiation images recorded on a stimulable phosphor sheet.

[Explanation of symbols]

1　　　　　Stormable phosphor sheet 2 Photography means 3 Reading means 4 Image processing means 5 Reproduction means 19 Stimulated luminescent light 41 Photo multiplier 42 Logarithmic amplifier 43 A/D converter

Claims (3)

[Claims] Claim 1: A subject is irradiated with radiation, a radiation image of the subject is captured on a recording medium, the radiation image is read from the recording body to obtain an image signal, this image signal is subjected to image processing, and then this In a radiographic imaging and reading method for reproducing a visible image based on an image signal subjected to image processing, prior to main imaging in which a radiographic image of the subject is captured on the recording medium, a method normally used for the main imaging in advance is used. Preliminary imaging is performed to image the subject on the recording body using a small dose of radiation, which is approximately one-tenth to one-tenth of the radiation dose, and the radiation image obtained by the preliminary imaging is set to temporary reading conditions. to obtain an image signal, perform image processing on the image signal based on temporary image processing conditions, reproduce a visible image based on the image signal subjected to the image processing, and reproduce the visible image. imaging conditions for performing the actual imaging based on the actual imaging; reading conditions for reading the image signal from the recorded body on which the actual imaging has been performed; and image processing conditions for performing image processing on the image signal obtained by the actual imaging. , perform the main imaging based on the imaging conditions, read an image signal from the recording medium on which the main imaging was performed based on the reading conditions, and obtain an image obtained by the main imaging based on the image processing conditions. 1. A radiographic image capturing and reading method, characterized in that a signal is subjected to image processing, and a visible image is reproduced based on the image signal obtained by the main radiographing that has been subjected to the image processing. 2. A radiation image of the subject is captured on a recording medium by irradiating the subject with radiation, the radiation image is read from the recording body to obtain an image signal, the image signal is subjected to image processing, and then the radiation image of the subject is captured on a recording body. In a radiographic imaging/reading device that reproduces a visible image based on image signals subjected to image processing, main imaging is performed in which a radiation image of the subject is photographed on the recording medium, and radiation imaging normally used for the main imaging is performed in advance. an imaging means for performing pre-imaging of selecting a small dose of radiation of approximately one to several tenths of the radiation dose, irradiating the subject with the small radiation dose and photographing the recording body; A reading means for reading the radiation images obtained by the main radiography and the previous radiography to obtain an image signal, an image processing means for performing image processing on the image signal, and a visible image based on the image signal subjected to the image processing. based on the visible image obtained from the previous imaging, the imaging conditions for the main imaging, and the reading conditions for reading the radiographic image obtained by the main imaging to obtain an image signal. and a condition determining means for determining image processing conditions for performing image processing on the image signal obtained by reading the radiation image obtained by the main imaging. 3. A subject is irradiated with radiation, a radiation image of the subject is captured on a recording medium, the radiation image is read from the recording body to obtain an image signal, this image signal is subjected to image processing, and then this In a radiographic imaging/reading device that reproduces a visible image based on image signals subjected to image processing, main imaging is performed in which a radiation image of the subject is photographed on the recording medium, and radiation imaging normally used for the main imaging is performed in advance. an imaging means for performing pre-imaging of selecting a small dose of radiation of approximately one to several tenths of the radiation dose, irradiating the subject with the small radiation dose and photographing the recording body; A reading means for reading the radiation images obtained by the main radiography and the previous radiography to obtain an image signal, an image processing means for performing image processing on the image signal, and a visible image based on the image signal subjected to the image processing. a reproduction means for reproducing the visible image from the radiographic image obtained by the previous radiography, the imaging conditions at the time of the main radiography, and the time when the radiation image obtained by the main radiography is read to obtain an image signal. and a condition correction means for correcting the image processing conditions when performing image processing on the image signal obtained by reading the radiation image obtained by the main imaging. reading device.