JP2896799B2 - Radiation image reading condition and / or image processing condition determination device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image reading condition and / or image processing condition determining device for obtaining reading conditions and image processing conditions based on an image signal representing a radiation image. is there.

2. Description of the Related Art In various fields, reading a recorded radiation image to obtain an image signal, performing appropriate image processing on the image signal, and reproducing and recording the image have been performed in various fields. For example,
An X-ray image is recorded using an X-ray film having a low gamma value designed to be compatible with the subsequent image processing, and the X-ray image is read from the film on which the X-ray image is recorded and converted into an electric signal. By subjecting the electric signal (image signal) to image processing and reproducing it as a visible image in a copy photograph or the like, a reproduced image having good image quality performance such as contrast, sharpness, and graininess is obtained. Yes
61-5193).

In addition, the applicant has set forth radiation (X-ray, α-ray, β-ray, γ
A part of this radiation energy is accumulated when irradiated with an electron beam, an electron beam, ultraviolet rays, etc., and thereafter, when irradiated with excitation light such as visible light, a stimulable phosphor (stimulated luminescence) which exhibits stimulated emission according to the accumulated energy. Using a phosphorescent substance) to temporarily record radiation image information of a subject such as a human body on a sheet-shaped stimulable phosphor, and scan the stimulable phosphor sheet with excitation light such as a laser beam to stimulate and emit light. Generates light, obtains an image signal by photoelectrically reading the resulting photostimulated light, and outputs a radiation image of the subject as a visible image to a recording material such as a photographic photosensitive material or a CRT based on this image data. A radiation image recording / reproducing system for causing the
56-11395, 55-163472, 56-104645, 5
No. 5-116340).

This system has the practical advantage of being able to record images over a very large radiation exposure area compared to conventional radiographic systems using silver halide photography. That is, in the case of the stimulable phosphor, it has been recognized that the amount of emitted light that is stimulated by excitation after accumulation is proportional to the radiation exposure amount over an extremely wide range. Even if fluctuates considerably, the amount of the stimulating light emitted from the stimulable phosphor sheet is read by the photoelectric conversion means with the reading gain set to an appropriate value and converted into an electric signal. By outputting a radiation image as a visible image on a recording material such as a photographic light-sensitive material or a display device such as a CRT using, a radiation image which is not affected by a change in radiation exposure can be obtained.

In the above-described system, before obtaining an image signal by reading under optimal reading conditions according to the dose of radiation applied to the stimulable phosphor sheet, the stimulable phosphor sheet is scanned with a low-level light beam in advance. A pre-read for reading the outline of the radiation image recorded on the sheet is performed, a pre-read image signal obtained by the pre-read is analyzed, and then the sheet is irradiated with a high-level light beam and scanned, and the radiation image is scanned. There is also a system configured to perform a main reading in which an image signal is obtained by reading under an optimum reading condition.

Here, the reading condition is a general term for various conditions that affect the relationship between the amount of stimulated emission light in reading and the output of the reading device row. For example, a reading gain and a scale factor that determine the relationship between input and output Alternatively, it means the power of excitation light in reading.

Further, the high level / low level of the light beam means that the energy of the light beam applied per unit area of the sheet is large / small or the energy of the stimulated emission light emitted from the sheet is the light beam. (Having a wavelength sensitivity distribution) means the magnitude of the weighted energy after weighting the energy of the light beam irradiated per unit area of the sheet by the wavelength sensitivity. Methods for changing the beam level include using a light beam of a different wavelength, changing the intensity of the light beam emitted from a laser light source, etc., and inserting or removing an ND filter or the like in the optical path of the light beam. How to change the beam intensity, how to change the scanning density by changing the beam diameter of the light beam, how to change the scanning speed, etc.
Various known methods can be used.

In addition, regardless of whether the system performs the pre-reading or the system which does not perform the pre-reading, the obtained image signal (including the pre-reading image signal) is analyzed, and an optimum image processing condition when performing image processing on the image signal is determined. Some systems let you decide. Here, the image processing condition is a general term for various conditions when a process that affects the gradation and sensitivity of a reproduced image based on an image signal is performed on the image signal. The method for determining the optimum image processing conditions based on this image signal is not limited to a system using a stimulable phosphor sheet, and obtains an image signal from a radiation image recorded on a recording sheet such as a conventional X-ray film. It is also applied to the system.

The calculation for obtaining the reading condition and / or the image processing condition (hereinafter, referred to as a reading condition or the like) based on the image signal (including the pre-read image signal) is performed based on a result of statistically processing a large number of radiation images in advance. The algorithm is defined (for example, Japanese Patent Application Laid-Open No. 60-185944,
-280163).

This conventionally employed algorithm generally obtains a histogram of an image signal, and calculates various values such as the maximum value and the minimum value of the image signal on the histogram, the value of the image signal at the point where the appearance frequency of the image signal is the maximum, and the like. Are obtained, and reading conditions and the like are obtained based on the characteristic points.

However, in recent years, the concept of a neutral network that is completely different from the above algorithm has appeared,
It is being applied to various fields.

This neural network inputs information (teacher signal) as to whether an output signal output when a certain input signal is given is a correct signal or an incorrect signal, and thereby, a signal between each unit in the neural network is input. It is equipped with an error reverse propagation learning (back propagation) function of correcting the weight of the connection (weight of the synaptic connection), and by repeatedly 'learning'
It is possible to increase the probability of outputting correctness when a new signal is input. (For example, "DERumelh
art, GEHinton and RJWilliams: Learning represent
ations by back-propagating errors, Nature, 323-9,5
33-356, 1986a "," Hideki Aso: Back Propagation Computrol No. 24 53-60 "," Kazuyuki Aihara, Neural Computer, Tokyo Denki University Press ").

This neural network can be applied to determination of reading conditions and the like, and reading conditions and the like can be output by inputting image signals and the like to the neural network.

(Problems to be Solved by the Invention) If the above neural network is used for determining the reading conditions, etc., it is possible to gradually obtain correct reading conditions etc. by repeatedly performing 'learning' in advance. In a system for handling an X-ray image of a subject, for example, the shoulder of a human body, various fluctuations, for example, a right shoulder and a left shoulder (inversion of an image), an enlarged image and a reduced image, an erect image, a horizontal image, and an inverted image, In order to construct a neural network that can obtain correct reading conditions and the like even if there is an image or the like in which a position shift has occurred, it is necessary to use a neural network having a very large number of units, and a connection between the units is required. The storage capacity of the storage device for storing the weights of the data must be enormous, and 'learning' must be performed. There is a problem that it is necessary to repeat a very large number of times learning when to I.

In view of the above problems, the present invention provides a radiographic image reading condition and / or a radiographic image reading condition that can obtain a correct reading condition or the like using a neural network having a relatively small number of units even when an input image fluctuates variously. It is an object of the present invention to provide an image processing condition determining device.

(Means for Solving the Problems) One aspect of the present invention is applied to a so-called pre-reading system using the above-described stimulable phosphor sheet. That is, the radiation image reading condition and / or image processing condition determining apparatus of the present invention irradiates the stimulable phosphor sheet on which the radiation image is recorded with excitation light and emits the stimulated emission light emitted from the stimulable phosphor sheet. On the basis of the first image signal representing the radiation image obtained by reading, the excitation light is again irradiated on the stimulable phosphor sheet to read the stimulable emission light emitted from the stimulable phosphor sheet, and Radiation image reading conditions and / or image processing condition determination for obtaining reading conditions for obtaining a second image signal representing a radiation image and / or image processing conditions for performing image processing on the obtained second image signal In the apparatus, storage means for storing a standard pattern of the radiation image, and the radiation image carried by the first image signal is converted to the standard pattern, the converted Signal converting means for obtaining a converted image signal carrying a ray image; and condition determining means comprising a neural network which receives the converted image signal as input and outputs the reading condition and / or the image processing condition. It is assumed that.

Further, another one of the present invention is not limited to the stimulable phosphor sheet, but also seeks image processing conditions. That is, the radiation image processing condition determining apparatus of the present invention is a radiation image processing condition determining apparatus that obtains image processing conditions when performing image processing on an image signal based on an image signal representing the radiation image. Storage means for storing a suitable pattern; a signal conversion means for converting a radiation image carried by the image signal into the standard pattern to obtain a converted image signal carrying the converted radiation image; A condition determining means comprising a neutral network which receives the converted image signal as input and outputs the image processing condition as output.

Here, regarding the “standard pattern of the radiographic image”, what kind of pattern is used as the standard pattern is not limited to a specific pattern in the present invention, and can be arbitrarily determined based on a design concept or the like. It is a matter that can be determined.

Further, in the present invention, "converting to the standard pattern" is not limited to a specific operation,
For example, inversion, rotation, position adjustment, enlargement, reduction, and the like of the radiation image carried by the first image signal.

(Operation) According to the present invention, a standard pattern of a radiation image is stored, and when an image signal (including a first image signal) as a basis for obtaining reading conditions and image processing conditions is obtained, the image signal After the radiographic image carried by the image signal is converted into a standard pattern, the converted image signal (converted image signal) is input to the neural network. And a small-scale neural network can be used. The storage capacity of the storage device for storing the weight of the connection between the units can be small, and the reading conditions and the image processing conditions of the same accuracy can be reduced. The number of times of 'learning' until it can be obtained can be reduced. In other words, if various target patterns are not input as they are, but are converted into standard patterns and then input, the burden of learning and recognition of the neutral network is reduced,
The scale can be reduced. For example, if there are two types of right shoulder image and left shoulder image as target images, the right shoulder image is stored as a standard pattern, and if the left shoulder image is given as an input image, Is inverted and converted into an image like a right shoulder image (a standard pattern), and then the image is input to a neural network. Since learning is sufficient, the scale (the number of hidden layers and the number of neurons in the neural network) can be reduced as compared to a neural network in which both the right shoulder and the left shoulder must be learned.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Here, an example in which an X-ray image of a shoulder of a human body is handled by using the above-described stimulable phosphor sheet will be described.

 FIG. 4 is a schematic diagram of an example of an X-ray imaging apparatus.

The X-ray source 2 of the X-ray imaging apparatus 1 irradiates the X-ray 3 toward the shoulder 4a of the human body 4 and irradiates the stimulable phosphor sheet 11 with the X-ray 3a transmitted through the human body 4. A transmission X-ray image of the shoulder 4a of the human body is stored and recorded on the stimulable phosphor sheet 11.

1A and 1B are diagrams schematically showing an example of a shoulder X-ray image accumulated and recorded on a stimulable phosphor sheet.

1A and 1B show X-ray images of the right shoulder and the left shoulder, respectively, and irradiate X-rays not irradiating the object directly to the stimulable phosphor sheet 11 in addition to the object portion 5 where the shadow of the human body is recorded. The formed straight X-ray part 6 is formed.

FIG. 5 is a perspective view showing an example of an X-ray image reading apparatus and an example of a computer system including an example of the present invention. This system uses the above-described stimulable phosphor sheet to perform pre-reading.

The stimulable phosphor sheet 11 on which the X-ray image is recorded is first scanned by a weak light beam to release only a part of the radiation energy stored in the stimulable phosphor sheet 11 to perform prefetching. It is set at 100 predetermined positions. The stimulable phosphor sheet 11 set at this predetermined position is conveyed (sub-scanning) in the direction of arrow Y by sheet conveying means 13 such as an endless belt driven by a motor 12.
On the other hand, the weak light beam 15 emitted from the laser light source 14 is reflected and deflected by the rotating polygon mirror 16 driven by the motor 23 and rotated at high speed in the direction of the arrow, passes through the focusing lens 17 such as an fθ lens, Is changed and the light is incident on the stimulable phosphor sheet 11, and the main scanning is performed in the arrow X direction substantially perpendicular to the sub-scanning direction (arrow Y direction). From the portion of the stimulable phosphor sheet 11 irradiated with the light beam 15,
Stimulated luminescence light 19 of the amount corresponding to the stored and recorded radiation image information is diverged, and the stimulated luminescence light 19 is guided by a light guide 20 to form a photomultiplier (photomultiplier tube).
21 photoelectrically detected. The light guide 20 is made by molding a light guide material such as an acrylic plate,
A linear incident end face 20a is arranged so as to extend along the main scanning line on the stimulable phosphor sheet 11, and the light receiving face of the photomultiplier 21 is joined to the annularly formed exit end face 20b. I have. Light guide 20 from the incident end face 20a
The stimulated emission light 19 that has entered the inside of the light guide 20 repeats total reflection, travels from the exit end face 20b, is received by the photomultiplier 21, and is generated by the stimulated emission light 19 representing a radiation image. The light quantity is converted into an electric signal by the photomultiplier 21.

The analog output signal S output from the photomultiplier 21 is logarithmically amplified by a logarithmic amplifier 26, and the A / D converter 2
Digitization is performed in step 7 to obtain a pre-read image signal Sp. The signal level of the pre-read image signal Sp is proportional to the logarithm of the amount of stimulated emission light emitted from each pixel of the sheet 11.

In the pre-reading, the reading conditions, that is, the voltage value applied to the photomultiplier 21, the amplification factor of the logarithmic amplifier 26, and the like are set so that the radiation energy stored in the stimulable phosphor sheet 11 can be read over a wide area. Is stipulated.

The obtained look-ahead image signal Sp is transmitted to the computer system 40.
Is input to The computer system 40 includes an example of the present invention. The computer system 40 includes a main body section 41 containing a CPU and an internal memory, a drive section 42 into which a floppy disk as an auxiliary memory is inserted and driven, and an operator It comprises a keyboard 43 for inputting necessary instructions and the like to the CRT 40 and a CRT display 44 for displaying necessary information.

In the computer system 40, the reading conditions at the time of the main reading, that is, the sensitivity and the contrast at the time of the main reading are obtained as described later, and for example, the voltage value applied to the photomultiplier 21 'and the logarithmic amplifier are determined according to the sensitivity and the latitude. The amplification factor of 26 'is controlled.

Here, the contrast corresponds to the light amount ratio of the strongest stimulated emission light to the weakest stimulated emission light which is converted into an image signal at the time of main reading, and the sensitivity is defined as a predetermined amount of the stimulated emission light. It refers to a light transmission conversion rate that determines which level of an image signal is the emitted light.

The pre-read stimulable phosphor sheet 11 'is set at a predetermined position of the main reading means 100', and the sheet 11 'is scanned by a light beam 15' stronger than the light beam used for the pre-read, and a pre-read image signal is read. An image signal can be obtained based on the reading condition obtained based on Sp. However, since the configuration of the main reading unit 100 ′ is substantially the same as the configuration of the pre-reading unit 100, the pre-reading unit 1
The constituent elements corresponding to the constituent elements of 00 are indicated by adding dashes to the numbers used in the look-ahead means 100, and description thereof will be omitted.

Image signal obtained by being digitized by A / D converter 27 'S _Q is input again to the computer system 40. Appropriate image processing on the image signal S _Q is a computer system 40 within are subjected, the image signal subjected to the image processing is sent to a not-shown reproducing apparatus, X-rays image is reproduced and displayed based on the image signal in the playback device Is done.

Next, a method of obtaining a reading condition at the time of main reading based on the pre-read image signal Sp in the computer system 40 will be described.

Since we are dealing with X-rays of the shoulder here, Fig. 1A,
As shown in FIG. 1B, a substantially horizontally inverted image may be obtained. The image of the right shoulder (Fig. 1A)
Or an image of the left shoulder (FIG. 1B).
In this embodiment, the image of the right shoulder (FIG. 1A) is regarded as a standard pattern according to the present invention.

2A and 2B are diagrams showing a standard pattern and an inverted pattern, respectively, stored in advance in the computer system 40. FIG.

These standard and inverted patterns are shown in Fig. 1A,
A first region 7 having an average value of the pre-read image signal Sp corresponding to the subject portion 5 of the X-ray image shown in FIG.
A second area 8 having an average value of the pre-read image signal Sp read from the direct X-ray part 6 of the X-ray image shown in FIG. 1B.

When the pre-read image signal Sp is input into the computer system 40, pattern matching between the pre-read image signal Sp and the standard pattern shown in FIG. 2A and the inverted pattern shown in FIG. Then, it is determined whether the input pre-read image signal Sp is a signal representing the right shoulder X-ray image or a signal representing the left shoulder X-ray image. Here, this pattern matching uses signals carrying a standard pattern and an inverted pattern (FIGS. 2A and 2B) respectively.
Assuming that S _S and S _R , the square values (S _S −Sp) ² and (S _R −Sp) ² of the difference from the pre-read image signal Sp are obtained for each pixel corresponding to each other, and these are calculated for the entire image. the amount obtained by adding stood Q _S, Q _R is _{Q S = Σ (S S -Sp} ) 2 ... (1) Q R = Σ (S R -Sp) 2 ... (2) is determined, the preliminary read-out image signal Sp There it is determined that the X-ray image bearing is these quantities Q _S, the image corresponding to the smaller of either the value of the Q _R.

If the image carried by the pre-read image signal Sp determined in this way is the X-ray image of the left shoulder (FIG. 1B), the operation of turning the X-ray image over (reversing) on the pre-read image signal Sp I do. As a result, the right shoulder image in FIG. 1A or the left shoulder image inverted (transformed) so as to look like a standard pattern right shoulder image is always input to the neural network shown below.

The pattern of the image input in this way is a predetermined standard pattern (here, the right shoulder pattern)
By inputting the information to the neural network after the adjustment, the number of units constituting the neural network can be reduced, and the capacity for storing the superimposition coefficient indicating the degree of coupling between the units can be reduced. Learning can be performed in a relatively short time.

Fig. 3 shows backpropagation learning (back propagation)
FIG. 2 is a diagram illustrating an example of a neural network having a function. Error Back Propagation Learning (Back Propagation)
As described above, the “learning” algorithm that sequentially corrects connection weights (synapse connection weights) from the output side to the input side by comparing the output of the neural network with the correct answer (teacher signal), as described above. Say.

As shown in the figure, the first of this neural network
Layer (input layer), second layer (intermediate layer), a third layer (output layer) is _one n respectively, _two n, consists of two units. The signals F ₁ , F ₂ ,..., F _n1 input to the first layer (input layer) are X
A pre-read image signal Sp corresponding to each pixel of a line image (in the case of the left shoulder, an inverted image), and two outputs from the third layer (output layer) Are signals corresponding to the sensitivity and the contrast at the time of main reading. I-th unit in k-th layer Each output The weight of the connection to And each unit Are the same characteristic function Shall be provided. At this time, Becomes However, each unit constituting the input layer Each input F ₁ to, F _2, ..., F _n1 intact units without being weighted Is input to The input n ₁ signals F ₁ , F ₂ ,…, F _n1 are
Weight of each connection Final output while weighted by The reading conditions (sensitivity and contrast) for the main reading are obtained.

Here, the weight of each connection Will be described. First, weight of each connection by random numbers Is given. In this case, even if the input F ₁ to F _n1 is varied to the maximum, the output Is preferably limited to a value within a predetermined range or a value close to the predetermined range.

The stimulable phosphor sheet on which many X-ray images of the right shoulder or the X-ray image of the left shoulder whose optimum reading conditions are known is read as described above to obtain the pre-read image signal Sp, and further, the X-ray of the left shoulder is obtained. for line image is pre-reading image signal Sp obtained is inverted, thereby the n ₁ inputs _{F 1, F 2, ...,} F n1 is obtained. The n ₁ inputs F ₁ , F ₂ ,..., F _n1 are input to the neural network shown in FIG. Is monitored.

Each output Is the final output And the teacher signal (sensitivity) as the correct reading condition for this image And contrast Square error with Is required. In order to minimize these square errors E ₁ and E ₂ , the weight of each connection is calculated as follows. Is corrected. The following About the output of Since this is the same as above, it is omitted here.

To minimize the square error E ₁ , this E ₁ Is a function of Weight of each connection as Is corrected. Here, η is a coefficient called a learning coefficient.

here And from equation (4) Therefore, equation (9) is Becomes

Here, from equation (6), By transforming equation (11) using equation (5), Here, from equation (3), f '(x) = f (x) (1-f (x)) (13) Becomes

When k = 2 in equation (10), and substituting equations (12) and (14) into equation (10), Substituting equation (15) into equation (8), Becomes According to this equation (16), Are modified.

next, Therefore, substituting equations (4) and (5) into equation (17), Here, from equation (13), Therefore, this equation (19) and equations (12) and (14) are
8) Substituting into the formula, In equation (10), we set k = 1 and substitute equation (20) into equation (10). When this equation (21) is substituted into equation (8), k = 1 is set, and And was corrected by equation (16) Is substituted into this equation (22), Is corrected.

Theoretically, by using the equations (16) and (22), the learning coefficient η is made sufficiently small and the number of times of learning is made sufficiently large, so that the weight of each connection is obtained. Can be converged to a predetermined value, but making the learning coefficient η too small is not realistic because the progress of learning is slowed down. On the other hand, if the learning coefficient η is increased, the learning may oscillate (the weight of the connection does not converge to a predetermined value). Therefore, in practice, vibration is suppressed by adding an inertia term such as the following equation to the correction amount of the weight of the connection, and the learning coefficient η is set to a relatively large value.

(E.g., DERumelhart, GEHinton and RJWilliam
s: Learning internal representations by error propa
gation In Parallel Distributed Processing, Volume
1, JMLMcClelland, DERumelhart and The PDP Resea
rch Group, MIT Press, 1986b ") However Is the connection weight after correction in the t-th learning From the weight of the connection before correction Represents the correction amount obtained by subtracting. Α is a coefficient called an inertia term.

As the inertia term α and the learning coefficient η, for example, α = 0.9η = 0.2
Weight of each connection using 5 Is modified (learned), for example, 200,000 times. Is fixed to the final value. At the end of this learning, two outputs Are signals that correctly represent the sensitivity and contrast, respectively, at the time of main reading.

Then, after the learning is completed, the pre-reading image signal Sp representing the X-ray image is obtained as the reading condition at the time of the main reading, and this is input to the neural network shown in FIG.
The resulting output Is a signal representing the reading conditions (sensitivity and contrast) of the main reading for the X-ray image. Since this signal is obtained after the learning as described above, the signal accurately represents the reading condition at the time of the main reading.

The neural network is not limited to a three-layer structure, but may be a multilayer structure. Also, as for the number of units in each layer, each layer can be composed of an arbitrary number of units according to the number of pixels of the input pre-read image signal Sp, the accuracy of required reading conditions, and the like.

The voltage applied to the photomultiplier 21 'of the main reading means 100' and the amplification factor of the amplifier 26 'are controlled in accordance with the reading conditions obtained by the neural network as described above. Is performed.

In the above embodiment, the standard image (right shoulder image) is obtained by performing pattern matching on the X-ray image of the shoulder with the pattern shown in FIGS. 2A and 2B prior to inputting the image to the neural network. Or an inverted image (image of the left shoulder) is determined, and in the case of the inverted image (image of the left shoulder), an operation of inverting the image to match the standard image (image of the right shoulder) was performed. Is not limited to the image of the shoulder even if it handles left-right inversion, and can be applied to, for example, a system that handles images of left and right limbs, right / left-facing head, abdomen, etc. Things.

Further, the present invention is not limited to horizontal reversal. For example, when a stimulable phosphor sheet is set obliquely at the time of photographing and an image signal carrying an inclined image is obtained as a result, or when reading is performed. The direction of the set of the stimulable phosphor sheet is different, even if the image signal representing a tilted image or an inverted image or a rotation for correcting this to a normal orientation is obtained. It is also possible to correct images having different enlargement ratios (reduction ratios) such as direct X-ray imaging and indirect X-ray imaging, and when a desired subject is recorded at the edge of the image, The position may be adjusted so as to be arranged at the center of the image. Also, adjustment may be made for a plurality of combinations of these.

Further, in the above embodiment, the pre-reading means 100 and the main reading means 100 '
Are configured separately, but as described above,
Since the configuration of 100 and the main reading unit 100 'is substantially the same, the pre-reading unit 100 and the main reading unit 100' may be integrally used.
In this case, after pre-reading, the stimulable phosphor sheet 11
May be backed once, and the main reading may be performed by operating again.

When the pre-reading means and the main reading means are used together, it is necessary to switch the intensity of the light beam between the case of pre-reading and the case of main reading. As described above, as a method of this switching, the light from the laser light source is used. Various methods such as a method of switching the intensity itself can be used.

Further, in the above embodiment, the apparatus for obtaining the reading conditions at the time of the main reading in the computer system 40 has been described.
At the time of actual reading, reading is performed under predetermined reading conditions regardless of the pre-read image signal Sp.
Pre-reading on the basis of the image signal Sp, may be calculated image processing conditions for performing image processing on the image signal S _Q, also,
The computer system 40 may obtain both the reading conditions and the image processing conditions.

Further, in the above-described embodiment, the radiation image reading apparatus that performs the pre-reading has been described. However, the present invention can be applied to a radiation image reading apparatus that performs the reading corresponding to the above-mentioned main reading without performing the pre-reading. In this case, when reading, an image signal is obtained by reading under predetermined reading conditions, and a computer system is
Image processing conditions are obtained in 40, and image processing is performed on the image signal according to the obtained image processing conditions.

(Effects of the Invention) As described in detail above, according to the present invention, an image is converted into a standard pattern, and then reading conditions and image processing conditions are obtained using a neural network. In comparison, the scale of the neural network can be reduced, the storage capacity of the storage device for storing the neural network can be reduced, and the number of times of learning can be reduced.

[Brief description of the drawings]

1A and 1B show X-ray images of the right shoulder and left shoulder, respectively. FIGS. 2A and 2B show a standard pattern and an inverted pattern, respectively. FIG. 3 shows a neural network. FIG. 4 is a schematic view showing an example of an X-ray imaging apparatus, and FIG. 5 is a perspective view showing an example of an X-ray image reading apparatus and an example of a computer system including an example of the present invention. FIG. DESCRIPTION OF SYMBOLS 1 ... X-ray imaging apparatus, 2 ... X-ray source 5 ... Subject part, 6 ... Direct X-ray part 11, 11 '... Storable phosphor sheet 19, 19' ... Stimulated luminescence 21, 21 'photomultiplier 26,26' logarithmic amplifier 27,27 'A / D converter 40 computer system 100 prereading means 100' book reading means

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-114899 (JP, A) JP-A-1-291298 (JP, A) JP-A-2-81257 (JP, A)

Claims (4)

(57) [Claims] 1. A stimulable phosphor sheet on which a radiation image is recorded is irradiated with excitation light, and the stimulable light emitted from the stimulable phosphor sheet is read to represent the radiation image. A second image signal representing the radiation image obtained by irradiating the stimulable phosphor sheet with excitation light again based on the image signal and reading the stimulated emission light emitted from the stimulable phosphor sheet; In a radiation image reading condition and / or image processing condition determination device for determining image processing conditions for performing image processing on reading conditions and / or the obtained second image signal, a standard pattern of the radiation image is stored. Storage means, and a signal conversion means for converting the radiation image carried by the first image signal into the standard pattern, and obtaining a converted image signal carrying the converted radiation image, Serial converted image signal as an input the reading conditions and / or the radiographic image reading conditions and / or the image processing condition determining apparatus being characterized in that a condition determining means comprising a neural network to output the image processing conditions. 2. The method according to claim 1, wherein the conversion to the standard pattern is performed by any one of inversion, rotation, position adjustment, enlargement, and reduction of a radiographic image carried by the first image signal, or a plurality of these. The radiation image reading condition and / or image processing condition determination device according to claim 1, wherein the combination is a combination. 3. The method according to claim 1, wherein the image signal represents a radiation image.
A radiation image processing condition determining apparatus for determining image processing conditions when performing image processing on the image signal; a storage unit for storing a standard pattern of the radiation image; Signal conversion means for obtaining a converted image signal carrying the converted radiation image, and a condition determining means comprising a neural network for inputting the converted image signal and outputting the image processing condition. A radiation image processing condition determining apparatus comprising: 4. The method according to claim 1, wherein the conversion into the standard pattern is performed by inverting, rotating, adjusting the position of a radiographic image carried by the image signal.
The radiation image processing condition determining apparatus according to claim 3, wherein the apparatus is any one of enlargement and reduction or a combination of a plurality of these.