JP2002000593A - Imaging device, imaging system, imaging method, and storage medium - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To make it possible to measure a sensitivity state of an image receiving means for forming a photographed image in a simple, accurate and reproducible state, thereby enabling efficient photographing, and Provided is an imaging device capable of providing a good captured image. SOLUTION: A first image receiving means 106 forms a captured image of a subject based on incident light (incident X-rays) and outputs a signal of the captured image. The second image receiving means 108 is provided on the light receiving surface of the first image receiving means 106, and outputs a signal based on incident light. The measuring means 116 determines the first image receiving means 106 based on the correlation between the output corresponding to the amount of incident light of the first image receiving means 106 at the same position and the output corresponding to the amount of incident light of the second image receiving means 108. Is measured for the sensitivity to incident light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a photographing apparatus used in a device or system for irradiating a subject with radiation, photoelectrically converting radiation transmitted through the subject, and acquiring a photographed image of the subject. , A photographing system, a photographing method, and a computer-readable storage medium storing processing steps for executing the method.

[0002]

2. Description of the Related Art Conventionally, for example, as an X-ray imaging apparatus for medical diagnosis, an X-ray type apparatus (film imaging apparatus) using a combination of an intensifying screen and a film has been widely used.

In the X-ray photography method, first, X-rays transmitted through a subject (a subject) are made incident on an intensifying screen, and the energy of the X-rays is absorbed by a phosphor contained in the intensifying screen. Thereby, fluorescence is generated. Next, the film is exposed by the fluorescence of the intensifying screen. This allows X on the film
A line image is formed as a latent image. Then, the film is developed and fixed. Thereby, the X-ray image on the film is visualized, and a doctor or the like can read the image.

On the other hand, in recent years, with the advance of digital technology, X-ray imaging apparatuses that handle X-ray images as digital data have been actively developed.

[0005] For example, there is an X-ray imaging apparatus (photoelectric conversion imaging apparatus) using a flat panel sensor comprising a solid-state image sensor having sensitivity to incident X-rays. In this device, X-rays incident on a solid-state imaging device are converted into electric signals corresponding to the intensity of the X-rays, and the electric signals (analog signals) are digitized and taken out as digital data.
With such a configuration, it is expected that the speed of diagnosis and the quality of X-ray images will be improved.

In addition to the above-described film photographing apparatus and photoelectric conversion photographing apparatus, as a photographing apparatus used as a medical photographing apparatus, for example, an imaging plate (hereinafter also referred to as “IP”) as an image receiving means is used. CR to use
Devices, phosphors and image intensifiers (I.
I. ) Is combined to multiply a radiation image, and the multiplied image is captured by a sensor such as a solid-state image sensor via an optical system. There is an I-TV photographing apparatus. I-
The TV photographing apparatus is mainly used for moving image photographing called fluoroscopic photographing.

[0007]

However, the conventional photographing apparatus as described above has the following problems. Here, a film photographing apparatus, a CR photographing apparatus, a photoelectric conversion photographing apparatus, and an I.P. Focusing mainly on the I-TV imaging apparatus, its problems will be described.

(Problems of Film Photographing Apparatus) The file photographing apparatus is an apparatus for acquiring a radiographic image such as X-rays by using a combination of an intensifying screen and a film, that is, using a film as an image receiving means. Although this is a screen film type (hereinafter, also referred to as "S / F type") apparatus, there is a problem that an image output state on a film becomes unstable.

That is, the sensitivity of the film varies depending on the production lot and the control conditions, and a sensitivity difference of about 10% may be observed. Also, the film temperature during shooting is
It is known to have a greater effect on its sensitivity. Without notice of such a difference in the sensitivity of the film, the film used for photographing has a large variation in photographic density. In addition, when developing a film after photographing, the temperature of the developing solution, the developing time, and the degree of fatigue of the developing solution may greatly affect the photographic density.

Therefore, an S / F using a film having unstable sensitivity and photographic density as described above as an image receiving means.
It is very difficult to obtain an X-ray image with a constant photographic density with a system-based device. For this reason, a user (radiologist, etc.) has been forced to spend a great deal of labor such as constantly checking the film sensitivity and maintaining the automatic developing machine in order to stabilize the photographic density.

(Problem of CR Imaging Apparatus) A CR apparatus using IP as an image receiving means has a problem of fading of IP.

More specifically, first, “fading” is a phenomenon that decreases with time until radiation information accumulated in the IP is read by irradiation (between imaging and reading of the IP). It is known that the light emission amount is reduced by about 20% to 40% at 32 ° C. for one hour. On the other hand, in the IP, there is a usage form in which the IP is enclosed in a portable light-shielding body called a cassette and is carried to a shooting site. Therefore, in an IP reading device (IP reading device), the elapsed time from when the image is captured to when the image is read is unknown, and there is a problem that the image output state becomes unstable due to fade ink.

[0013] Suppose that the IP reading device uses
Even if the elapsed time until the reading of P is known, it is difficult to stabilize the image output state because the fading characteristic is affected by the temperature.

Further, the CR device outputs a photographed image having a constant density by changing the IP read gain regardless of fading characteristics and radiation dose, taking advantage of the advantage of acquiring a digital image. In some cases, the IP read gain value is used as a reference for the radiation dose. However, the IP read gain value corrects both the fading characteristic and the radiation dose at the same time. There was no means to know whether the irradiation dose was truly appropriate. For this reason, the radiation dose is determined based on the read gain value of the IP and the output image, but in such a configuration, the subject, in particular, the subject is a patient in the next imaging. In such a case, the patient may be exposed to excessive radiation.

(Problems of Photoelectric Conversion Photographing Apparatus) It is feared that an image output state is not stable even in an apparatus using a photoelectric conversion element as an image receiving means. The reason is,
That is, the characteristics of the photoelectric conversion element may change over time.

Specifically, first, a photoelectric conversion element is generally formed of a semiconductor element in which a small amount of a substance is doped into silicon single crystal, amorphous silicon, or the like. It is known to change in response. It is also known that when a long-term current is applied to a semiconductor element in an integrated manner, the semiconductor element may be stochastically degraded and the light input / output characteristics may be changed. These factors result in reduced stability of the image output state.

Further, in the photoelectric conversion element, there is a possibility that unevenness in sensitivity may occur for each pixel depending on various use environments.
Therefore, in order to solve this problem, it is conceivable to grasp the sensitivity of each pixel and correct the unevenness of sensitivity.However, due to the shading unique to the tube that generates radiation and the difference in distance, etc. There is a problem that the amount of incident radiation cannot be accurately grasped.

(I. Problems of I-TV Camera) I
The -TV photographing device also uses a sensor such as a solid-state imaging device, and therefore has a problem that the sensitivity of each pixel is not stable, as in the above-described photoelectric conversion device. In addition, I.
In order to periodically grasp the sensitivity of the sensor, the I-TV imaging apparatus uses a method of obtaining the sensitivity of the sensor by a radiation dose in an area different from the image, I. Since a method of attaching a camera for measurement is used instead of the permanent camera at the subsequent stage, there is a problem that it is troublesome and lacks accuracy and reproducibility.

Therefore, the present invention has been made to eliminate the above-mentioned drawbacks, and is configured so that the sensitivity of an image receiving means for forming a photographed image can be measured in a simple, accurate and reproducible state. Thus, a photographing apparatus, a photographing system, a photographing method, and a computer-readable storage medium storing a photographing apparatus, a photographing method, and a processing step for executing the photographing apparatus, which can efficiently perform photographing and always provide good photographed images The purpose is to provide.

[0020]

For such a purpose,
According to a first aspect, a first image receiving means for forming a captured image of a subject based on incident light from the subject and outputting a signal of the captured image, and a light receiving surface of the first image receiving means are provided. And one or more second image receiving means for outputting a signal based on the incident light, an output corresponding to an incident light amount of the first image receiving means at the same position, and an incident light amount of the second image receiving means. And a measuring unit for measuring a sensitivity state of the first image receiving unit to the incident light based on a corresponding output correlation.

According to a second aspect of the present invention, in the first aspect,
And a control unit for controlling an amount of incident light for obtaining the photographed image based on an output of at least one of the first image receiving unit and the second image receiving unit.

According to a third aspect, in the first aspect,
The second image receiving means has a light receiving surface of at least the same size as the light receiving surface of the first image receiving means.

According to a fourth aspect, in the first aspect,
Based on the quantum noise of the first image receiving means, the second
And a correcting means for correcting the output of the image receiving means.

According to a fifth aspect based on the first aspect,
The image processing apparatus further includes a correction unit configured to correct a sensitivity state of the first image receiving unit to incident light based on an environmental element of the first image receiving unit.

According to a sixth aspect, in the first aspect,
The image processing apparatus further includes a correction unit that corrects an output of the second image receiving unit based on an incident light amount obtained based on condition information of a light source of the incident light.

According to a seventh aspect, a first image receiving means for forming a photographed image of a subject based on incident light from the subject,
The sensitivity of the first image receiving unit to the incident light is measured based on a correlation between the amount of incident light of the first image receiving unit and the amount of incident light obtained based on the quantum noise of the first image receiving unit. The imaging device is provided with a measuring unit.

According to an eighth aspect, a first image receiving means for forming a photographed image of a subject based on incident light from the subject,
Measurement for measuring the sensitivity of the first image receiving means to incident light based on a correlation between the amount of incident light of the first image receiving means and the amount of incident light obtained based on the condition information of the light source of the incident light. And a photographing device comprising:

According to a ninth aspect, in the first aspect,
The second image receiving means is provided on a front surface or a rear surface of a light receiving surface of the first image receiving means.

According to a tenth aspect, in any one of the first, seventh and eighth aspects, at least one of the first image receiving means and the second image receiving means comprises a plurality of two-dimensional photoelectric conversion elements. The sensor includes at least one of a sensor having a light receiving surface, a sensor having high transmittance, and a sensor having high sensitivity.

An eleventh invention is characterized in that, in any one of the first, seventh, and eighth inventions, the incident light includes radiation transmitted through the subject.

A twelfth invention is a photographing system in which a plurality of devices are communicably connected to each other, wherein at least one device of the plurality of devices is connected to each other.
And a function of the imaging device according to any one of the above.

According to a thirteenth aspect of the present invention, there is provided a process for forming a photographed image of a subject based on the incident light from the subject and measuring the sensitivity of the first image receiving means for outputting a signal of the photographed image to the incident light. In the above-described processing step, an output corresponding to the amount of incident light of the first image receiving unit and a signal provided on a light receiving surface of the first image receiving unit and based on the incident light are included. A measuring step of measuring a sensitivity state of the first image receiving unit to the incident light based on a correlation with an output corresponding to an incident light amount of one or a plurality of second image receiving units to be output. I do.

In a fourteenth aspect based on the thirteenth aspect, the processing step includes the first image receiving means and the second image receiving means.
A control step of controlling the amount of incident light for obtaining the photographed image based on the output of at least one of the image receiving means.

In a fifteenth aspect based on the thirteenth aspect, the measuring step comprises: outputting an output corresponding to an incident light amount at an arbitrary position on a light receiving surface of the first image receiving means; Incident light of the first image receiving means based on a correlation with an output of the second image receiving means having a light receiving surface of at least the same size as the light receiving surface at an arbitrary position on the light receiving surface at the arbitrary position. And measuring a sensitivity situation with respect to.

In a sixteenth aspect based on the thirteenth aspect, the processing step estimates an output of the second image receiving means based on quantum noise of the first image receiving means,
A correcting step of correcting the output of the second image receiving means based on the estimated value.

In a seventeenth aspect based on the thirteenth aspect, the processing step acquires an environmental element including temperature information of the first image receiving means, and, based on the environmental element,
The method may further include a correction step of correcting the sensitivity of the first image receiving unit to incident light.

In an eighteenth aspect based on the thirteenth aspect, the processing step includes the step of outputting the output of the second image receiving means based on information on at least one of a setting of a light source of the incident light and a generation condition. The method includes a step of correcting the output of the second image receiving means based on the estimation and the estimated value.

According to a nineteenth aspect, there is provided an imaging method including a processing step for measuring a sensitivity state of the first image receiving means for forming a captured image of the subject based on the incident light from the subject with respect to the incident light, The processing step includes a step of estimating an incident light amount of the first image receiving unit based on the quantum noise of the first image receiving unit, and a correlation between the estimated value and the incident light amount of the first image receiving unit. Measuring the sensitivity of the first image receiving means to the incident light based on

According to a twentieth aspect, there is provided an imaging method including a processing step for measuring a sensitivity state of the first image receiving means for forming a captured image of the subject based on the incident light from the subject with respect to the incident light, The processing step includes: estimating an incident light amount of the first image receiving unit based on at least one of information on a setting and a generation condition of a light source of the incident light; Measuring the sensitivity of the first image receiving means to the incident light based on the correlation with the amount of incident light.

According to a twenty-first aspect, in the thirteenth aspect, the measuring step corresponds to an incident light amount of the second image receiving means provided on the front surface or the rear surface of the light receiving surface of the first image receiving means. The method includes a step of measuring the above-mentioned sensitivity status using an output.

In a twenty-second aspect based on any one of the thirteenth, nineteenth, and twentieth aspects, the processing step includes: transmitting the radiation transmitted through the subject to the first image receiving means and the second image receiving means. The method is characterized by including a step of causing the light to enter at least one of them.

According to a twenty-third aspect, a processing program for implementing the function of the photographing apparatus according to any one of claims 1 to 11 or the function of the photographing system according to claim 12 is stored in a computer-readable manner. It is characterized by being a storage medium.

According to a twenty-fourth aspect of the present invention, a computer-readable storage medium stores the processing steps of the photographing method according to any one of claims 13 to 22.

[0044]

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

(First Embodiment) The present invention provides, for example,
The present invention is applied to an X-ray imaging apparatus 100 as shown in FIG. As shown in FIG. 1, the X-ray imaging apparatus 100 includes an X-ray generation unit 101 that generates X-rays from an X-ray tube, an X-ray image imaging unit 104, and a digital output of the X-ray image imaging unit 104. A / D converter 103 and first X-ray detector 106
A for digitizing the output of the first X-ray detector 106
/ D converter 105, second X-ray detector 108,
A / D converter 107 for digitizing the output of line detector 108, temperature detector 109, A / D converter 108 for digitizing the output of temperature detector 109, and sensitivity due to environmental factors such as temperature information Correction table 110 for correcting a change in image data, and a look-up table 1 for matching gradation when displaying the output value of the first X-ray detection unit 106.
11, a memory 112, an output evaluator 113 for comparing a temporal change of each output value of the first X-ray detector 106 and the second X-ray detector 108, an external storage device 114, a display unit 115, Part 116, and X
Line generator 101, A / D converters 103 to 108, correction table 110, lookup table 111, memory 1
12, an output evaluation unit 113, an external storage device 114, a display unit 115, and a control unit 116
0 can be transmitted and received.

The memory 112 is a memory for storing various processing programs and data, and is also used as a working memory. The control unit 116 controls the CP
U and the like, and controls the operation of the entire X-ray imaging apparatus 100 by reading and executing the processing program from the memory 108. Thereby, the operation by the most characteristic configuration of the X-ray imaging apparatus 100 is performed.

FIGS. 2 and 3 show the most characteristic configuration of this embodiment in the X-ray imaging apparatus 100 shown in FIG.

As shown in FIG. 2, the first X-ray detector 1
Reference numeral 06 is provided in the X-ray image capturing unit 104 and is set at a position where X-rays generated from the X-ray tube 102 by the X-ray generating unit 101 pass through the subject 130 and enter. In addition, the first X-ray detecting unit 106
An X-ray detection sensor as an image receiving means for forming a photographed image of, for example, a detection surface having a plurality of two-dimensionally arranged photoelectric conversion elements.

A series of operations of the X-ray imaging apparatus 100 will be described with reference to FIG. 2. First, the X-ray emitted from the X-ray tube 102 by the X-ray
Is irradiated. The first X-ray detection unit 106 detects an X-ray transmitted through the subject 130 and outputs an electric signal (image signal) thereof. This output is output from the A / D converter 1 shown in FIG.
05, and digitized by the control unit 11
6. The control unit 116 performs image processing or the like on the image data from the A / D converter 105, and supplies the processed image data to the display unit 115 as captured image (X-ray image) data of the subject 130. Therefore, an X-ray image of the subject 130 is displayed on the display unit 115 on the screen.

Here, the most characteristic configuration of the present embodiment is a configuration for measuring the sensitivity of the first X-ray detector 106 and its change with time (hereinafter also referred to as “sensitivity situation”). Therefore, the X-ray imaging apparatus 100 according to the present embodiment
As shown in FIG. 3 (or FIG. 1), is configured to also include the second X-ray detection units 108a to 108c.
With this configuration, the X-ray dose of the first X-ray detection unit 106 estimated from the quantum noise of the first X-ray detection unit 106 for forming an X-ray image of the subject 130 and the X-ray dose of the second X-ray detection units 108a to 108c By comparing the correlation with the X-ray dose, a function of grasping the sensitivity status of the first X-ray detection unit 106 is realized.

Specifically, first, as the first X-ray detector 106 using the photoelectric conversion element, an a-Se sensor, an a-Si sensor combined with a phosphor, or the like can be applied. As a phosphor of the a-Si sensor, CaW04 or G
Intensifying screen coated with d2O2S: Tb on a support or Cs
A phosphor crystal such as 1 is used. Such a phosphor is
The radiation image is converted into a visible light image by the phosphor, because of the characteristic of emitting fluorescent light having an intensity proportional to the irradiation amount of radiation such as X-rays. Will be converted and output.

In this embodiment, as shown in FIG. 3, a plurality of second X-rays for grasping the sensitivity status of the first X-ray detector 106 are provided on the front or back of the first X-ray detector 106.
A configuration is provided in which the line detection units 108a to 108c are provided. With such a configuration, for example, as shown in FIG.
In a configuration in which the positions of the first X-ray detection unit 106 and the second X-ray detection unit 108 for grasping the sensitivity situation of the first X-ray detection unit 106 are different, the sensitivity situation of each part in the first X-ray detection unit 106 is grasped. Although not possible, in the configuration of FIG. 3 described above, it is possible to grasp the impression of each part in the first X-ray detection unit 106.

In the present embodiment, three second X-ray detectors 108a to 108c are provided. However, the number is not limited to one, and one or three or more second X-ray detectors 108a to 108c are provided. A configuration in which a line detection unit is provided may be employed.

The second X-ray detectors 108a to 108c
When the second X-ray detectors 108a to 108c are provided on the front surface of the X-ray detector 106, it is preferable to use an acrylic light guide plate and a sensor having good transmittance such as a photomultiplier or an ion chamber. When the second X-ray detectors 108a to 108c are provided on the back surface of the first X-ray detector 106, the second X-ray detectors 108a to 108c may be a scintillator, an a-Si sensor, an avalanche diode, a photomultiplier, or the like. Preferably, a sensitive sensor is used.

The second X-ray detectors 108a to 108c
Advantages of providing the detector on the back of the X-ray detector 106 include:
Since the second X-ray detectors 108a to 108c do not exist between the subject 130 and the first X-ray detector 106, the X-ray absorption and scattering by the second X-ray detectors 108a to 108c are small. That is, the image quality of the captured image (X-ray image) obtained by the step 106 is small.
Further, it is not necessary to take into account the geometric blur of the captured image due to the increase in the distance between the subject 130 and the first X-ray detection unit 106 by the thickness of the second X-ray detection units 108a to 108c.

In the configuration in which the second X-ray detectors 108a to 108c are provided on the back of the first X-ray detector 106, the voltage of the X-ray tube 102 (hereinafter, also simply referred to as "X-ray tube voltage").
The X-ray transmitted dose of the first X-ray detection unit 106 varies depending on the type of the X-ray detector, which causes a problem in grasping the sensitivity status of the first X-ray detection unit 106. However, by using an X-ray analyzer or the like, The sensitivity state of the first X-ray detection unit 106 can be grasped in consideration of the evaluation of the X-ray characteristics at the tube voltage. For example, an X-ray analyzer has a configuration in which a plurality of detectors covered with different filters are simply arranged on a plane, and it is assumed that X-rays are equally incident on the plurality of detectors. Although it cannot be used for the sensitivity comparison for each pixel in the fourth embodiment, it is effective because the influence of the X-ray tube voltage can be corrected when the artifact differs depending on the location of the sensor panel.

On the other hand, the second X-ray detectors 108a to 108c
Is provided on the front surface of the first X-ray detection unit 106, particularly, if the first X-ray detection unit 106 is a sensor using a phosphor, that is, the incident X-ray is converted into visible light using the phosphor. In such a configuration, it is necessary to consider the influence on the X-ray image, so that the use of incident X-rays is restricted more. However, the second X-ray detectors 108a to 108
c is provided on the back surface of the first X-ray detection unit 106,
There is an advantage that an accurate X-ray dose can be detected. The reason is that the X-ray transmission characteristics of the first X-ray detector 106 (X-ray tube 1
02 voltage dependency) can be avoided.

The second X-ray detectors 108a to 108a-1 as described above
08c is an X-ray exposure control unit 20 as shown in FIG.
1 is connected. The X-ray exposure control unit 201
The line detectors 108a to 108c (or the first X-ray detector 10
In contrast to 6), when a certain amount of X-ray is incident, the X-ray generation unit 101 controls the X-ray tube 102 to cut off the generation of X-rays at that time. As a result, the X-ray dose of the first X-ray detection unit 106 can be compared with the same X-ray dose each time, and the sensitivity status can be accurately grasped without any trouble (sensitivity measurement). It can also be applied as a photo timer when taking an image of a patient for diagnosis.

The control unit 116 compares the correlation between the X-ray dose (detected value) at the same position at the second X-ray detectors 108a to 108c and the X-ray dose (detected value) at the first X-ray detector 106 with a reference value. By doing so, the first X-ray detector 10
6 is measured.

As the reference value, for example, the X-ray dose of the second X-ray detectors 108a to 108c obtained by actually irradiating X-rays when the X-ray imaging apparatus 100 is shipped and the first X-ray detector 106 Indicating the correlation of the X-ray doses (standard values at the time of shipment), and the second X-rays obtained by irradiating X-rays by the X-ray generation unit 101 actually used in the X-ray imaging apparatus 100 when the apparatus 100 is installed. A value indicating the correlation between the X-ray dose of the X-ray detectors 108a to 108c and the X-ray dose of the first X-ray detector 106 (installation reference value) is used. As described above, the reason for using the two values, the reference value at the time of shipment and the reference value at the time of installation, is that the X-ray may have its own environment such as its own shading depending on the X-ray tube 102 of its generating part. This is because the reference value must be changed depending on the X-ray generation unit used.

Therefore, as shown in FIG. 5, the control unit 116 firstly supplies the second X-ray image obtained by actually irradiating the X-ray at the time of shipment of the X-ray imaging apparatus 100 (indicated by ""). A value indicating the correlation between the X-ray doses of the X-ray detectors 108a to 108c and the X-ray dose of the first X-ray detector 106 is set as a shipping reference value. Next, when the X-ray imaging apparatus 100 is installed (in FIG. Shown), a second X-ray detector 1 obtained by irradiating X-rays with an X-ray generator 101 actually used.
08a to 108c and the X-rays of the first X-ray detector 106
A value indicating the correlation of the dose is set as a reference value at the time of installation, and the reference value at the time of shipment and the reference value at the time of installation are stored in the memory 112. Then, the control unit 116 controls the X-ray generation unit 10 during the sensor sensitivity test (indicated by “” in the figure).
1 to generate X-rays, the X-ray dose obtained by the second X-ray detectors 108a to 108c and the first X-ray detector 106
By comparing the value indicating the correlation of the X-ray dose with the reference value stored in the memory 112 in advance, the first X-ray detector 10
6 is measured.

That is, the control unit 116
As shown in FIG. 1, first, at the time of shipping and installation of the X-ray imaging apparatus 100, each of the X-ray doses (hereinafter referred to as “correlation values” or “detection values”) of the first X-ray detection unit 106 and the second X-ray detection units 108a to 108c. ) Is compared with the reference value at the time of shipment, which can be compared with other sensors, and the X-ray imaging apparatus 1.
An X-ray tube-dependent reference value (tube-dependent reference value) at the installation location of 00 is created and stored in the memory 112. Then, the controller 116 periodically compares the correlation values from the first X-ray detection unit 106 and the second X-ray detection units 108a to 108c using the reference value in the memory 112, so that the first X-ray The sensitivity of the detection unit 106 is measured and output.

In the control section 116, the following processing is executed as specific processing for measuring the sensitivity state of the first X-ray detection section 106. Here, an example of the process will be described.

As a processing method for measuring the sensitivity of the first X-ray detection unit 106 to incident X-rays, a pixel value (at this time, the incident X-ray dose from the captured image data obtained from the first X-ray detection unit 106) Pixel value) and the second
Using the outputs of the X-ray detectors 108a to 108c, the first
A method of estimating the sensitivity of the X-ray detector 106 to incident X-rays, a method of estimating the sensitivity of the first X-ray detector 106 to incident X-rays from the amount of quantum noise in the first X-ray detector 106, and the like are given.

For example, a method for estimating the sensitivity of the first X-ray detector 106 to incident X-rays from the amount of quantum noise in the first X-ray detector 106 will be specifically described as an example. Is a random phenomenon, and its frequency is accompanied by noise because its frequency follows the law of statistics. Here, “quantum noise” (X-ray quantum noise) indicates the noise. When the distribution of the quantum noise follows the Poisson distribution, the standard deviation of the output value is “√
(Radiation dose). " Therefore, if the amount of quantum noise is known, the sensitivity to incident radiation can be estimated.

Therefore, in the present embodiment, the noise existing in the first X-ray detector 106 and the second X-ray detectors 108a to 108c is regarded as system noise, and the first X-ray detector 10
The quantum noise is obtained by subtracting the system noise from the noise appearing in the captured image obtained in step 6. Accordingly, the sensitivity of the first X-ray detection unit 106 can be measured, and if the result is displayed on the display unit 115, the user can perform the imaging operation while grasping the sensitivity of the first X-ray detection unit 106. It can be carried out.

In the case of a film photographing apparatus, the noise existing on the film may be used as the system noise.

As a processing method for measuring the change over time of the sensitivity of the first X-ray detector 106 to incident X-rays, here, first, as shown in FIG. Each output value of the 2X-ray detection units 108a to 108c is represented by a symbol.

In FIG. 7, “X” is the output value of each pixel of the first X-ray detector 106, “Y” is the output value of the second X-ray detector 108, and “Z” is the first X-ray detector 106. "A" represents the X-ray imaging apparatus 100
At the time of shipment, “b” is the time when the X-ray imaging apparatus 100 is installed,
“C” represents the time of the sensor sensitivity test in the X-ray imaging apparatus 100, respectively. In addition, “n” indicates the X-ray value when performing irradiation with a plurality of X-ray doses at the time of shipping the X-ray imaging apparatus 100.
The number of the types of doses (the number of measurements) is represented, where “n ′” represents the number of measurements at the time of installation, and “n ″” represents the number of measurements at the time of sensor sensitivity inspection.

Therefore, for example, the X-ray imaging apparatus 100
The output value of each pixel of the first X-ray detection unit 106 at the time of installation is represented by “Xb (1 to n ′)”, and the quantum noise (the result of subtracting the system noise from the output noise) at this time is It is represented by “Zb (1−n ′)”. The output values of the second X-ray detectors 108a to 108c at this time are as follows:
It is represented by “Yb (1 to n ′)”.

Therefore, first, at the time of shipment, the output value Xa of each pixel of the first X-ray detector 106 and the output value Y of the second X-ray detectors 108a to 108c are irradiated by irradiation of a certain X-ray amount.
a, Quantum noise Za of the first X-ray detector 106 is obtained. At the time of installation, the irradiation of a certain amount of X-ray
The output value Xb of each pixel of the X-ray detection unit 106, the output value Yb of the second X-ray detection units 108a to 108c, and the quantum noise Zb of the first X-ray detection unit 106 are obtained. Then, from the relationship of (Xb, Yb) at the time of installation, the following equation (1) is acquired: Function: Yb = f (Xb) (1) The expression (1) is used as a reference (a reference corresponding to the above-described shipping reference value and installation reference value).

The output value at the time of shipment is obtained in order to obtain a sensitivity difference between a plurality of panels. This is because the characteristics of the X-ray generator, such as the effective energy, generally differ depending on the setting place of the device.

Next, at the time of sensor sensitivity inspection, the output value Xc of each pixel of the first X-ray detector 106 and the output value Y of the second X-ray detectors 108a to 108c are irradiated by irradiation of a certain X-ray amount.
c, acquire the quantum noise Zc of the first X-ray detector 106. Then, from the relationship (Xc, Yc) at the time of the sensor inspection, the following equation (2) is obtained: Function: Yc = f (Xc) (2)

Therefore, the above equations (1) and (2)
Can be measured, the change over time in the sensitivity of the first X-ray detector 106 can be measured.

As described above, according to the present embodiment, the X-ray dose in the first X-ray detector 106 and the second X-ray detector 10
By comparing the correlation with the X-ray dose in 8a to 108c and the reference obtained in advance, the sensitivity of the first X-ray detection unit 106 and its temporal change can be measured. Therefore, the user can perform an imaging operation efficiently while grasping the sensitivity of the first X-ray detection unit 106,
A good captured image can be obtained.

(Second Embodiment) In this embodiment,
In the X-ray imaging apparatus 100 shown in FIG.
The output values (Y) of the second X-ray detection units 108a to 108c are corrected based on the quantum noise (Z) of the line detection unit 106.
This correction function is performed by the control unit 116.

More specifically, the present embodiment will be described with reference to the symbols shown in FIG. 7. First, similarly to the first embodiment, at the time of shipment, the first X-ray detector 106
Output value Xa for each pixel, the second X-ray detectors 108a to 108a-1
08c and the quantum noise Za of the first X-ray detection unit 106 are obtained.
Output value Xb for each pixel of the second X-ray detectors 108a to 108a-1
The output value Yb of 08c and the quantum noise Zb of the first X-ray detector 106 are obtained.

Next, from the relation of (Yb, Zb) at the time of installation, the following equation (3) is obtained: Function: Yb = f (Zb) (3)

Next, at the time of the sensor sensitivity test, as in the first embodiment, the output value Xc of each pixel of the first X-ray detector 106, the output value Yc of the second X-ray detectors 108a to 108c, The quantum noise Zc of the first X-ray detector 106 is obtained.

Next, the estimated {Yb} is obtained by substituting the quantum noise Zc into the above equation (3). When the value of {Yb} is deviated from the actual value of Yc, the second X-ray detectors 108a to 108d outputting Yc
It is considered that the sensitivity to the incident X-ray 8c may have changed, and information (warning information) indicating that may be displayed on the display unit 1.
15 to notify the user by displaying a screen.

Then, using the estimated {Yb}, the above equation (1) and the above equation (2) are compared in the same manner as in the first embodiment.

As described above, in the present embodiment, the first X
Output values of the estimated second X-ray detection units 108a to 108c obtained based on the amount of quantum noise of the line detection unit 106,
If there is a gap between the actual output values of the second X-ray detection units 108a to 108c, a warning indicating that fact is output,
Since the output value is corrected, even if the sensitivity of the second X-ray detectors 108a to 108c to the incident X-rays changes, the first X-ray detector 1
06 and its change with time can be measured.
Also, instead of the output values of the second X-ray detectors 108a to 108c, the second X-ray detectors 108a to 108 of the estimation obtained based on the amount of the quantum noise of the first X-ray detector 106 are used.
If the configuration using the output value of c is used, the second X-ray detector 10
Since it is not always necessary to provide 8a to 108c, the size of the apparatus can be reduced.

(Third Embodiment) In the present embodiment,
In the X-ray imaging apparatus 100 shown in FIG.
Based on environmental factors such as temperature information of the line detection unit 106, the first
The sensitivity of the X-ray detector 106 to incident X-rays is corrected.
This correction function is performed by the control unit 116.

Specifically, first, the first X-ray detector 106
It is known that the output value of the photoelectric conversion element used in the above varies depending on environmental factors such as temperature. For example,
FIG. 8 shows the temperature dependence of the output of the photoelectric conversion element. In FIG. 8, the horizontal axis represents the temperature of the photoelectric conversion element, and the vertical axis represents the relative output based on the output at a temperature of 25 ° C. Further, a solid line represents an output of the photoelectric conversion element when a predetermined light amount is given, and a dotted line represents a dark output of the photoelectric conversion element when light is blocked.

As shown in FIG. 8, the output of the photoelectric conversion element when a predetermined amount of light is given increases gradually with the rise in temperature, while the dark output of the photoelectric conversion element when light is blocked increases rapidly with the rise in temperature. To increase. As a result, the first X-ray detector 10
6 may not be stable depending on the warm-up state of the X-ray imaging apparatus 100.

As a method for stabilizing the sensitivity of the first X-ray detection unit 106 to incident X-rays, there are the following methods: at the time of the sensor sensitivity inspection of the first X-ray detection unit 106, a method of performing the sensitivity inspection under a constant temperature. . A method of correcting the sensitivity of the first X-ray detector 106 to incident X-rays based on the detection value of the temperature detector 109 shown in FIG. and so on.

In this embodiment, for example, the temperature detector 1
The sensitivity to the incident X-rays of the first X-ray detection unit 106 is corrected based on the detection value of 09 so that the first X-ray detection unit 106 is not affected by the temperature change.

That is, the time-dependent change is measured by measuring the sensitivity at 25 ° C., and the temperature of the first X-ray detection unit 106 is changed by the detection value (detection temperature) of the temperature detection unit 109 due to the heat generated from the electric parts. If it ’s higher,
The sensitivity of the first X-ray detector 106 to the incident X-ray is corrected based on the detected temperature.

When the sensitivity of the first X-ray detection unit 106 to the incident X-ray has been corrected, information indicating the correction is displayed to the user on the display unit 115 to notify the user. For example, both the current sensitivity information and the corrected sensitivity information are displayed. This allows the user to use the current sensitivity information
An image can be taken with an optimum X-ray dose without giving an extra X-ray dose to the subject 130 (patient or the like). Further, it is possible to know a change with time of the sensitivity of the first X-ray detection unit 106 from the corrected sensitivity information.

As described above, in the present embodiment, the first X
Since the sensitivity of the first X-ray detection unit 106 to the incident X-ray is corrected based on environmental factors such as the temperature information of the line detection unit 106, the first X-ray detection unit 106 can be appropriately adjusted without being affected by the environment such as temperature change. X-ray imaging can be performed, and the sensitivity of the first X-ray detection unit 106 and its temporal change can be measured.

(Fourth Embodiment) In the present embodiment,
In the X-ray imaging apparatus 100 shown in FIG.
Instead of the line detectors 108a to 108c, a configuration is provided in which a second X-ray detector 108 'as shown in FIG. 9 is provided. The second X-ray detector 108 ′ is a sensor having substantially the same size as the entire surface of the first X-ray detector 106.

Specifically, first, the first X-ray detector 106
There is a possibility that the sensitivity of the photoelectric conversion element used in the method may be changed depending on the different use environment of each pixel. The main causes of this are manufacturing errors for each pixel and X
It is considered that there is an error in the amount of radiation exposure or the like, or the influence of external impact or heat generation.

Therefore, in the present embodiment, FIG.
As shown in (2), the second X-ray detector 108 'having a structure extending over the entire surface of the first X-ray detector 106 is provided on the front or back of the first X-ray detector 106. Not only the overall sensitivity and its temporal change, but also the temporal change of the sensitivity can be measured for each pixel.

(Fifth Embodiment) In the present embodiment,
In the X-ray imaging apparatus 100 shown in FIG. 1, the first X-ray detector 106 arrives from the condition information such as the set value of the X-ray generator 101 (information including the set value and the condition at the time of X-ray generation). Correct X-ray dose. This correction function is performed by the control unit 116.

Specifically, first, generally, the X-ray dose can be estimated from the set values of the voltage and current of the X-ray tube of the X-ray generation unit, the irradiation time, and the like. In particular, tube current (mA)
It has been experimentally confirmed that the X-ray dose is substantially proportional to the “mAs” value calculated from the irradiation time (s) and the irradiation time (s).

Therefore, in the present embodiment, for example, the amount of X-rays reaching the first X-ray detector 106 is calculated from the set value of the X-ray generator 101, and this calculation result is used as the second X-ray detectors 108a to 108a. It is used instead of the output value of 108c (or 108 '). Alternatively, the second X-ray detectors 108a to 108c
(Or 108 ') for correcting the output value. With such a configuration, the second X-ray detectors 108a to 108c
(Or 108 '), even if the sensitivity to incident X-rays changes, the second X-ray detectors 108a to 108c
Since the X-rays reaching the first X-ray detector 106 can be used instead of the output value of (or 108 ′), the sensitivity of the first X-ray detector 106 and its temporal change are always accurately measured. be able to. Also, the second X-ray detector 108
If the X-rays reaching the first X-ray detector 106 are used instead of the output values of a to 108c (or 108 '), the second X-ray detectors 108a to 108c (or 108')
Since it is not always necessary to provide ′), the size of the device can be reduced.

In the first to fifth embodiments, the present invention is applied to the X-ray imaging apparatus 100 as shown in FIG. 1, but the present invention is not limited to this. In addition to various medical measurements, it can be applied to uses such as nondestructive inspection.

The present invention is also applicable to an apparatus or system using X-rays or other radiation. For example, by transmitting radiation such as β and γ-rays to the object to be measured, and using the absorption and backscattering of the radiation at this time, the thickness of the object to be measured and the thickness of the upper layer of the multilayer having different materials are measured. Or
The present invention is also applicable to devices and systems for measuring density.

It is another object of the present invention to provide a storage medium storing program codes of software for realizing the functions of the host and the terminal according to the first to fifth embodiments to a system or an apparatus, and to provide the system or the apparatus with the storage medium. By reading and executing the program code stored in the storage medium by the computer (or CPU or MPU) of the device,
Needless to say, this is achieved. In this case, the program code itself read from the storage medium implements the functions of the first to fifth embodiments, and the storage medium storing the program code constitutes the present invention. As storage media for supplying the program code, ROM, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-RO
M, CD-R, magnetic tape, nonvolatile memory card, and the like can be used. By executing the program code read by the computer, the first to fifth programs are executed.
Not only the functions of the embodiment are realized, but also the OS or the like running on the computer performs part or all of the actual processing based on the instruction of the program code, and the processing performs the first to the first processing. It goes without saying that a case where the functions of the fifth embodiment are realized is also included. Further, after the program code read from the storage medium is written into a memory provided in an expansion board or a function expansion unit connected to the computer, the program is expanded based on the instructions of the program code. A CPU or the like provided in the board or the function expansion unit performs a part or all of the actual processing, and the first to
It goes without saying that a case where the function of the fifth embodiment is realized is also included.

[0100]

As described above, according to the present invention, at least the following effects can be obtained.

(1) The incident light amount of the first image receiving means and the second
If the configuration is such that the sensitivity state of the first image receiving unit is measured based on the correlation between the incident light amounts of the image receiving units, the user can determine the sensitivity state (the sensitivity and the sensitivity thereof) of the first image receiving unit that forms a captured image. Changes over time) are automatically obtained at any time.
It is possible to shoot efficiently. Further, if the second image receiving means is provided on the front surface or the rear surface of the first image receiving means, more accurate measurement of the sensitivity can be performed.

(2) If the configuration is such that the amount of incident light for obtaining a captured image is controlled based on the output of at least one of the first image receiving means and the second image receiving means, an appropriate amount of light can be obtained. You can shoot with this is,
For example, in radiography, to prevent subject (patient) from being exposed to more radiation than necessary (reduction of exposure dose)
It is effective for etc. Further, it is possible to easily adjust the amount of incident light when measuring the sensitivity situation. Further, for example, in a film-type photographing apparatus, it is not necessary to attach a phototimer detector, so that there is no waste in space and cost, which is effective.

(3) If the second image receiving means has a light receiving surface having at least the same size as that of the light receiving surface of the first image receiving means, the sensitivity of the entire light receiving surface of the first image receiving means can be improved. Since the situation can be measured, it is possible to measure the sensitivity situation in each portion (each pixel portion and the like) of the light receiving surface. For example, even when there is shading of a light source (radiation tube or the like) of the incident light or a difference in the distance from the light source to a subject, the sensitivity status at each part of the light receiving surface of the first image receiving unit can be accurately measured. can do.

(4) The output of the second image receiving means is corrected based on the quantum noise of the first image receiving means or based on the incident light amount obtained based on the condition information of the incident light source. According to this configuration, even when the sensitivity of the second image receiving unit to the incident light changes, it is possible to appropriately cope with the change and more accurate measurement of the sensitivity situation can be performed.

(5) If the sensitivity state of the first image receiving means to the incident light is corrected based on the environmental elements (temperature information and the like) of the first image receiving means, the sensitivity state excluding the environmental elements can be corrected. Can be measured.

(6) The amount of light incident on the first image receiving means and the first
The sensitivity of the first image receiving means to the incident light is measured based on the correlation with the amount of incident light obtained based on the quantum noise of the image receiving means. If the sensitivity state of the first image receiving unit to the incident light is measured based on the correlation between the light amount and the incident light amount obtained based on the condition information of the light source of the incident light, the second image receiving unit Without it, the sensitivity situation of the first image receiving means can be measured. As a result, the size of the device or system can be reduced.

The present invention, which has the above-described effects, can be applied to, for example, a film photographing apparatus, a CR photographing apparatus, a photoelectric conversion photographing apparatus, and an I.P. When applied to an I-TV photographing apparatus, at least the following effects can be obtained. It goes without saying that the present invention is not limited to the application to the above-described device.

(Film Photographing Apparatus) With the configuration described in the above (1), the user can easily grasp the film sensitivity without spending much labor for checking the film sensitivity. Further, with the configuration described in (2) above, the second image receiving means for measuring the sensitivity state of the first image receiving means controls the generation of radiation when the radiation dose to the film reaches a predetermined value. Since it can be used in place of the photo timer, it is possible to avoid overlapping in terms of space and it is effective in terms of cost.

(CR device) The above (1), (4),
With the configurations described in (5) and (6), it is possible to accurately determine whether or not the radiation irradiation amount is truly appropriate, so that the subject (patient) is reliably exposed to excessive radiation. Can be prevented.

(Photoelectric Conversion Imaging Apparatus, II-TV Imaging Apparatus) With the configuration described in the above (5), a change in sensitivity due to temperature can be corrected. Further, with the configuration described in the above (3), the incident dose for each pixel can be accurately grasped, and the change over time in the sensitivity of each pixel can be accurately grasped.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an X-ray imaging apparatus to which the present invention is applied in a first embodiment.

FIG. 2 is a diagram illustrating a main configuration of the X-ray imaging apparatus.

FIG. 3 is a diagram for explaining the most characteristic configuration of the X-ray imaging apparatus.

FIG. 4 is a diagram for explaining a comparison between the most characteristic configuration of the X-ray imaging apparatus and another configuration.

FIG. 5 is a diagram for explaining a process for grasping the sensitivity status of a first X-ray detection unit of the X-ray imaging apparatus.

FIG. 6 is a diagram for explaining the processing in a control unit that executes the processing for grasping the sensitivity situation.

FIG. 7 is a diagram for explaining symbols used for explaining a process for grasping the sensitivity status of the first X-ray detection unit.

FIG. 8 is a diagram for explaining the relationship between the output of the photoelectric conversion element of the first X-ray detector and the temperature in the third embodiment.

FIG. 9 is a diagram for describing a most characteristic configuration of the X-ray imaging apparatus according to the fourth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 X-ray imaging apparatus 101 X-ray generation unit 102 X-ray tube 104 X-ray image imaging unit 106 First X-ray detection unit 108 (108 a to 108 b) Second X-ray detection unit 112 Memory 115 Display unit 116 Control unit 130 Subject 201 X Line exposure control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G01T 1/20 G01T 1/20 E 5F088 J 1/24 1/24 1/29 1/29 C H01L 31 / 09 H04N 5/225 C H04N 5/225 Z 5/232 Z 5/232 5/32 5/32 7/18 L 7/18 H01L 31/00 A F-term (reference) 2G088 EE03 FF02 GG19 GG20 GG21 JJ05 LL15 LL21 LL26 4C093 AA03 CA10 CA32. BB07 LA08

Claims (24)

[Claims] A first image receiving unit that forms a captured image of the subject based on incident light from the subject and outputs a signal of the captured image; and a light receiving surface of the first image receiving unit. One or more second image receiving means for outputting a signal based on incident light, and an output corresponding to the amount of incident light of the first image receiving means at the same position and corresponding to the amount of incident light of the second image receiving means And a measuring means for measuring the sensitivity of the first image receiving means to the incident light based on the correlation between the outputs. 2. A control means for controlling an amount of incident light for obtaining the photographed image based on an output of at least one of the first image receiving means and the second image receiving means. The photographing device according to claim 1. 3. The photographing apparatus according to claim 1, wherein said second image receiving means has a light receiving surface at least as large as a light receiving surface of said first image receiving means. 4. The photographing apparatus according to claim 1, further comprising correction means for correcting an output of said second image receiving means based on quantum noise of said first image receiving means. 5. The photographing apparatus according to claim 1, further comprising correction means for correcting the sensitivity of the first image receiving means to incident light based on environmental factors of the first image receiving means. 6. The photographing apparatus according to claim 1, further comprising a correction unit configured to correct an output of the second image receiving unit based on an incident light amount obtained based on condition information of a light source of the incident light. apparatus. 7. A first image receiving means for forming a photographed image of the object based on incident light from the object, an incident light amount of the first image receiving means, and a quantum noise of the first image receiving means. A photographing apparatus comprising: a measuring unit that measures a sensitivity state of the first image receiving unit to the incident light based on a correlation with the obtained incident light amount. 8. A first image receiving means for forming a captured image of a subject based on incident light from the subject, an amount of incident light on the first image receiving means, and condition information of a light source of the incident light. A measuring device for measuring a sensitivity state of the first image receiving device to the incident light based on a correlation with the incident light amount. 9. The photographing apparatus according to claim 1, wherein said second image receiving means is provided on a front surface or a rear surface of a light receiving surface of said first image receiving means. 10. A sensor having a light receiving surface on which a plurality of photoelectric conversion elements are two-dimensionally arranged, a sensor having a high transmittance, and a sensor having a high transmittance, wherein at least one of the first image receiving means and the second image receiving means is provided. 9. The photographing apparatus according to claim 1, further comprising at least one of a sensitivity sensor. 11. The imaging apparatus according to claim 1, wherein the incident light includes radiation transmitted through the subject. 12. An imaging system in which a plurality of devices are communicably connected to each other, wherein at least one of the plurality of devices is a function of the imaging device according to any one of claims 1 to 11. An imaging system comprising: 13. An imaging method comprising: a processing step for measuring a sensitivity state to incident light of a first image receiving means for forming a captured image of the object based on incident light from the object and outputting a signal of the captured image; In the method, the processing step includes an output corresponding to an incident light amount of the first image receiving unit and a signal provided on a light receiving surface of the first image receiving unit and outputting a signal based on the incident light. Alternatively, the imaging method includes a measuring step of measuring a sensitivity state of the first image receiving unit to the incident light based on a correlation with an output corresponding to the amount of incident light of the plurality of second image receiving units. 14. The processing step includes a control step of controlling an incident light amount for obtaining the photographed image based on an output of at least one of the first image receiving means and the second image receiving means. The photographing method according to claim 13, further comprising: 15. The measuring step has an output corresponding to an amount of incident light at an arbitrary position on a light receiving surface of the first image receiving means, and a light receiving surface of at least the same size as the light receiving surface of the first image receiving means. Measuring a sensitivity state of the first image receiving unit to the incident light based on a correlation with an output corresponding to an incident light amount at the arbitrary position on the light receiving surface of the second image receiving unit. 14. The photographing method according to claim 13, wherein: 16. The processing step estimates an output of the second image receiving means based on quantum noise of the first image receiving means, and corrects an output of the second image receiving means based on the estimated value. 14. The photographing method according to claim 13, further comprising a correction step of performing the correction. 17. The processing step comprising: acquiring an environmental element including temperature information of the first image receiving unit, and correcting a sensitivity state of the first image receiving unit to incident light based on the environmental element. 14. The method according to claim 13, further comprising a step. 18. The processing step estimates an output of the second image receiving means based on at least one of information on a setting of a light source of the incident light and a generation condition, and on the basis of the estimated value, 14. The photographing method according to claim 13, further comprising a correction step of correcting an output of the second image receiving means. 19. A photographing method including a processing step for measuring a sensitivity state of a first image receiving means for forming a photographed image of a subject based on incident light from the subject with respect to the incident light, wherein the processing step is performed. Based on the quantum noise of the first image receiving means,
Estimating the incident light amount of the image receiving means, and measuring the sensitivity state of the first image receiving means to the incident light based on the correlation between the estimated value and the incident light amount of the first image receiving means. A photographing method comprising: 20. A photographing method including a processing step for measuring a sensitivity state of a first image receiving means for forming a photographed image of the subject based on the incident light from the subject with respect to the incident light, wherein the processing step includes: Estimating the amount of incident light of the first image receiving unit based on at least one of the setting of the light source of the incident light and the generation condition, the estimated value, and the amount of incident light of the first image receiving unit. Measuring the sensitivity of the first image receiving means to the incident light based on the correlation of (1). 21. The measuring step includes measuring the sensitivity state by using an output corresponding to an incident light amount of the second image receiving means provided on a front surface or a rear surface of a light receiving surface of the first image receiving means. 14. The method of claim 13, further comprising the step of: 22. The apparatus according to claim 13, wherein said processing step includes a step of causing radiation transmitted through said subject to be incident on at least one of said first image receiving means and said second image receiving means. , And 20. 23. A computer readable processing program for implementing the function of the photographing apparatus according to claim 1 or the function of the photographing system according to claim 12. Storage medium. 24. A storage medium, wherein the processing steps of the imaging method according to claim 13 are stored in a computer-readable manner.