JP2005109908A - Image processor and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor which obtains optimum image processing conditions, irrespective of factors having influences on the quality of a radiation image in generating data of the radiation image, thereby automatically obtaining an optimum image for diagnoses without troublesome operations. <P>SOLUTION: The image processor 2 for applying image processes to data of a plurality of radiation images produced by radiation photographing apparatus having different constitutions comprises a means 24f for determining image processing conditions for applying the image process, based on factors having influences on the quality of the radiation image when the photographing apparatus generate the data of the radiation images. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus and an image processing program for performing image processing on radiographic image data, and more particularly to an image processing apparatus and an image processing program capable of performing optimal image processing on radiographic image data.

  In recent years, an apparatus capable of directly capturing a radiographic image as a digital image has been developed. For example, a radiographic apparatus that irradiates subject radiation, detects the amount of radiation transmitted through the subject with a detector using a stimulable phosphor, and obtains a radiation image corresponding to the detected amount as an electrical signal is known. (See, for example, “Patent Documents 1 and 2”).

  In addition, a charge corresponding to the intensity of the radiation that has passed through the subject is generated in the photoconductive layer, the generated charge is stored in a plurality of two-dimensionally arranged capacitors, and the stored charge is taken out to generate radiation. A radiographic apparatus that obtains an image as an electrical signal has been proposed. Such a radiation imaging apparatus uses a detector called a flat panel detector (FPD) that detects a fluorescence intensity corresponding to a radiation dose with a photodiode, a CCD, or a C-MOS sensor (for example, “Patent Document 3”). 4 ”).

  Further, the radiographic apparatus can be classified into a standing apparatus, a standing apparatus, a cassette apparatus, and the like depending on the arrangement of the subject and the detector when capturing a radiographic image of the subject. The standing device is, for example, a device that photographs a subject such as a patient in a standing posture, the standing device is a device that photographs a subject in a standing posture, and the cassette device is a detector. This is an apparatus for taking a radiographic image using a cassette whose arrangement can be freely changed with respect to a subject.

  With respect to the radiographic image data of the subject obtained by these radiographic apparatuses, the image processing apparatus uses a floor where the portion of interest of the doctor, that is, the region of interest (ROI) has a gradation suitable for diagnosis. In general, the tone conversion process is performed.

By the way, the human body structure can be divided into soft tissue such as fat and muscle and bone tissue, but depending on the diagnosis site, the main diagnostic object may be soft tissue or bone tissue. . Further, the ratio of the soft tissue and the bone tissue varies depending on the patient, who is the subject, depending on the patient's body shape, bone thickness, bone density, organ size, and the like. Therefore, when image processing such as gradation conversion processing is performed on the radiographic image data, the radiographic image data is analyzed, and the human body structure that is the main diagnostic target and the human body structure that is the subordinate diagnostic target are each subjected to image processing. The image processing condition factors are generated for each region of interest, the image processing conditions are determined based on the plurality of image processing condition factors, and the image processing is performed. A technique is known in which an optimum image processing condition is automatically obtained regardless of the ratio between the bone part and the soft part (see, for example, “Patent Document 5”).
JP-A-55-12429 Japanese Unexamined Patent Publication No. 63-189853 Japanese Patent Laid-Open No. 9-90048 JP-A-6-342098 JP 2001-212118 A

  However, when the abdominal front of the same patient is photographed by the standing device and the prone device, respectively, as shown in FIG. 2 (a), in the case of the standing device, the soft tissue in the patient's abdomen is on the chest and lower abdomen side. It tends to be biased to (region A shown in the figure). On the other hand, as shown in FIG. 3A, in the case of the supine device, the soft tissue in the patient's abdomen tends to be biased toward the flank side (region B shown in the figure). For this reason, there is a difference in the thickness of the soft tissue in the front of the patient's abdomen, compared with the case where the image is taken with the standing device and the case where the image is taken with the supine device. Differences in the amount of radiation detected.

  Further, depending on the radiation imaging apparatus, a scatterer that scatters radiation, such as a photo timer or a mat for reducing the physical load on the patient, may be provided between the subject and the detector. In some cases, a radiographic image of a subject is captured using a scattered radiation removal grid for removing such scattered radiation. Therefore, even when the same part of the same patient is imaged by the standing device, if the presence or absence of the scatterer or the grid ratio of the scattered radiation removal grid is different, a difference occurs in the radiation dose detected by the detector.

  In this way, if the factors that affect the image quality of the radiographic image differ depending on the radiographic apparatus used for imaging, the signal value of the radiographic data data obtained even when the same part of the same patient is imaged There is a difference in the histogram which is the frequency distribution, and as a result, there is a case where the image quality such as density, sharpness, and contrast of the radiation image varies.

  However, in the conventional image processing method (for example, Patent Document 5), based on information (for example, an imaging region) obtained only from image data to be processed without considering factors that differ depending on the radiation imaging apparatus as described above. Since the image processing conditions were determined, the radiographic images obtained by the plurality of radiographic apparatuses varied in image quality, and were unsuitable for use as a comparative interpretation image.

The image quality variation described here refers to the following.
Examples include differences in contrast and density of images that change depending on the gradient of the gradation curve after gradation conversion and the difference in slide amount, and differences in sharpness due to frequency enhancement processing.
For example, when a frontal image of the abdomen is taken, the concentration of the abdominal central soft part and the concentration of the flank line, or the concentration of gas contained in the body in both the image taken by the standing device and the image taken by the supine device Therefore, if there is a large difference between the density of the image photographed by the standing device and the density of the image photographed by the standing device, there arises a problem that it is difficult to make a diagnosis in comparative interpretation.

  An object of the present invention is to obtain an optimal image processing condition regardless of factors that affect the image quality of a radiographic image generated when generating radiographic image data, and automatically generate an optimal image for diagnosis without complicated operations. It is an object to provide an image processing apparatus and an image processing program that can be obtained.

  In order to solve the above-described problem, the invention according to claim 1 is an image processing apparatus that performs image processing on data of a plurality of radiation images generated by radiation imaging apparatuses having different configurations. The image processing condition determining means for determining an image processing condition for performing the image processing based on a factor that affects the image quality of the radiographic image when generating image data is provided.

  According to a second aspect of the present invention, in the image processing apparatus that performs image processing on a plurality of radiographic image data generated by radiographic apparatuses having different configurations, the radiographic image is generated when the radiographic image data is generated by the radiographic apparatus. The image processing algorithm determining means for determining an image processing algorithm for performing the image processing based on a factor affecting the image quality of the image processing apparatus is provided.

  According to a third aspect of the present invention, in the image processing apparatus according to the second aspect, a region of interest that determines, as a region of interest, a region in which the influence of the factor is unlikely to appear in the data of the radiation image based on the image processing algorithm. Based on the determining means, the image processing condition factor generating means for generating an image processing condition factor based on the data of the radiation image included in the region of interest determined by the region of interest determining means, and the image processing condition factor, And image processing condition determining means for determining an image processing condition for performing the image processing.

  According to a fourth aspect of the present invention, in the image processing apparatus according to any one of the first to third aspects, the factor includes a subject and a radiation amount provided in the radiation imaging apparatus and transmitted through the subject. It includes an arrangement relationship with a detector to be detected.

  According to a fifth aspect of the present invention, in the image processing apparatus according to the fourth aspect, the factor includes a movement characteristic of a soft tissue of a subject depending on a relative arrangement relationship between the detector and the subject. To do.

  According to a sixth aspect of the present invention, in the image processing apparatus according to the fourth aspect, the factor includes a relative distance between the detector and the subject.

  According to a seventh aspect of the present invention, in the image processing apparatus according to the fourth aspect, the factor includes the presence / absence of a scatterer interposed between the detector and the subject.

  The invention according to claim 8 is the image processing apparatus according to any one of claims 1 to 7, wherein the factor is a grid ratio of a grid for removing scattered radiation used when generating data of the radiation image. It is characterized by including.

  According to a ninth aspect of the present invention, in the image processing apparatus according to any one of the first to eighth aspects, the image processing is performed in order to correct a variation in image quality between the radiographic images caused by the factor. It is characterized by being.

  According to a tenth aspect of the present invention, in the image processing apparatus according to any one of the first and third to ninth aspects, the image processing condition determining means is any one of the radiographic apparatuses having the different configurations. The image processing conditions are determined based on radiation image data generated by the radiation imaging apparatus.

  According to an eleventh aspect of the present invention, in the image processing apparatus according to the second or third aspect, the image processing algorithm determination means is generated by any one of the radiographic apparatuses having the different configurations. The image processing algorithm is determined based on the radiographic image data.

  An image processing program according to a twelfth aspect of the present invention provides a computer for performing image processing on a plurality of radiographic image data generated by radiographic apparatuses having different configurations, and the radiographic image data by the radiographic apparatus. An image processing condition determining function for determining an image processing condition when performing the image processing is realized based on a factor that affects the image quality of the radiation image at the time of generation.

  According to a thirteenth aspect of the present invention, there is provided an image processing program comprising: a computer for executing image processing on a plurality of pieces of radiation image data generated by radiation imaging apparatuses having different configurations; An image processing algorithm determination function for determining an image processing algorithm for performing the image processing is realized based on a factor that affects the image quality of the radiation image at the time of generation.

  According to a fourteenth aspect of the present invention, in the image processing program according to the thirteenth aspect, based on the image processing algorithm to be realized by the computer, a region where the influence of the factor is less likely to appear in the data of the radiographic image. A region-of-interest determination function that determines the region of interest, an image processing condition factor generation function that generates an image processing condition factor based on the radiographic image data included in the region of interest determined by the region-of-interest determination means, and the image And an image processing condition determining function for determining an image processing condition for performing the image processing based on a processing condition factor.

  According to a fifteenth aspect of the present invention, in the image processing program according to any one of the twelfth to fourteenth aspects, the factor is a subject and a radiation amount provided in the radiation imaging apparatus and transmitted through the subject. It includes an arrangement relationship with a detector to be detected.

  According to a sixteenth aspect of the present invention, in the image processing program according to the fifteenth aspect, the factor includes a movement characteristic of a soft tissue of a subject depending on an arrangement relationship between the detector and the subject.

  According to a seventeenth aspect of the present invention, in the image processing program according to the fifteenth aspect, the factor includes a distance between the detector and the subject.

  According to an eighteenth aspect of the present invention, in the image processing program according to the fifteenth aspect, the factor includes the presence / absence of a scatterer interposed between the detector and the subject.

  The invention according to claim 19 is the image processing program according to any one of claims 12 to 18, wherein the factor is a grid ratio of a grid for removing scattered radiation used when generating data of the radiation image. It is characterized by including.

  According to a twentieth aspect of the present invention, in the image processing program according to any one of the twelfth to eighteenth aspects, the image processing corrects a variation in image quality that occurs between data of a plurality of radiation images due to the factor. It is performed to do.

  According to a twenty-first aspect of the present invention, in the image processing program according to any one of the twelfth and fourteenth to twentieth aspects, the image processing condition determining means is any one of the radiation imaging apparatuses having the different configurations. The image processing conditions are determined based on radiation image data generated by the radiation imaging apparatus.

  According to a twenty-second aspect of the present invention, in the image processing program according to the thirteenth or fourteenth aspect, the image processing algorithm determining means is generated by any one of the radiation imaging apparatuses having the different configurations. The image processing algorithm is determined based on the radiographic image data.

  According to the first and twelfth aspects of the present invention, the image processing apparatus includes an image processing condition determining unit, and the radiographic image is determined according to the image processing condition determined based on a factor that affects the image quality when generating the radiographic image data. Since the image processing is performed on the data, it is possible to obtain the optimum image processing conditions excluding the influence of the difference in the signal value distribution caused by the above factors, and automatically obtain the optimum image for diagnosis without complicated operations. It becomes possible.

  According to the second and thirteenth aspects of the present invention, the image processing apparatus includes an image processing algorithm determination unit, and the radiographic image is determined according to an image processing algorithm determined based on a factor that affects the image quality when generating the radiographic image data. Since image processing is performed on the data, it is possible to obtain an optimal image processing algorithm that eliminates the influence of signal value distribution differences caused by the above factors, and automatically obtains an optimal image for diagnosis without complicated operations It becomes possible.

  According to the invention described in claims 3 and 14, in the radiographic image data, an area where the influence of the factor is less likely to appear is set as a region of interest, and the image processing condition factor is based on the radiographic image data included in the region of interest. Therefore, it is possible to obtain optimal image processing conditions excluding the influence of the image quality of the radiographic image generated by using a radiation imaging apparatus with a different configuration, and automatically generate the optimal image for diagnosis without complicated operations. Can be obtained.

  According to the fourth and fifteenth aspects of the present invention, an optimum image processing condition can be obtained in consideration of the arrangement relationship between the subject and the detector, and a plurality of radiographic images can be obtained using radiographic apparatuses having different configurations. Even when data is generated, image quality variations caused by differences in signal value distribution between radiographic image data due to the difference in the positional relationship between the subject and the detector are corrected, making it ideal for diagnosis without complicated operations. Images can be obtained automatically.

  According to the inventions described in claims 5 and 16, the optimum image processing conditions can be obtained in consideration of the movement characteristics of the soft tissue of the subject due to the arrangement relationship between the subject and the detector. Even when a plurality of radiographic image data is generated using an imaging device, the variation in image quality caused by the difference in signal value distribution between the radiographic image data due to the difference in moving characteristics of the soft tissue of the subject is corrected. Thus, it is possible to automatically obtain an optimal image for diagnosis without complicated operations.

  According to the invention described in claims 6 and 17, the optimum image processing conditions can be obtained in consideration of the distance between the subject and the detector, and data of a plurality of radiographic images are obtained using radiographic apparatuses having different configurations. Even when the image is generated, the image quality variation caused by the difference in the signal value distribution between the radiographic image data due to the difference in the distance between the subject and the detector is corrected, and the optimum image for diagnosis can be obtained without complicated operations. It can be obtained automatically.

  According to the invention described in claims 7 and 18, the optimum image processing conditions can be obtained in consideration of the presence or absence of a scatterer interposed between the subject and the detector, and radiation imaging apparatuses having different configurations are used. Even when multiple radiological image data are generated, the variation in image quality caused by the difference in signal value distribution between each radiographic image data due to the presence or absence of the scatterer is corrected, making it ideal for diagnosis without complicated operations. It is possible to automatically obtain a correct image.

  According to the invention described in claims 8 and 19, the optimum image processing condition can be obtained in consideration of the grid ratio of the grid used at the time of data generation, and a plurality of radiations can be obtained using radiation imaging apparatuses having different configurations. Even when image data is generated, the image quality variation caused by the difference in signal value distribution between the radiation image data due to the difference in grid ratio is corrected, and the optimal image for diagnosis is automatically created without complicated operations. Can be obtained.

  According to the inventions of claims 9 and 20, correction of image quality variations caused by differences in signal value distribution between the data of the respective radiographic images caused by the above factors is corrected by using radiographic apparatuses having different configurations. can do.

  According to the invention described in claims 10 and 21, a signal between data of each radiographic image generated by using a radiographic apparatus having a different configuration by determining an image processing condition based on any one radiographic image. It is possible to correct variations in image quality caused by a difference in value distribution. For example, by using, as a reference, radiographic image data that is an optimal image for diagnosis, other radiographic images can also be optimal images for diagnosis.

  According to the invention described in claims 11 and 22, a signal between data of each radiographic image generated by using a radiographic apparatus having a different configuration by determining an image processing condition based on any one radiographic image. It is possible to correct variations in image quality caused by a difference in value distribution. For example, by using, as a reference, radiographic image data that is an optimal image for diagnosis, other radiographic images can also be optimal images for diagnosis.

  Hereinafter, an image processing apparatus according to the best mode for carrying out the present invention will be described with reference to the drawings.

  The image processing apparatus according to the present invention performs image processing on radiographic image data generated by a plurality of radiation imaging apparatuses 1 having different configurations, and is applied to the image processing system 100 shown in FIG. The image processing system shown in FIG. 1 includes a plurality of radiation imaging apparatuses 1, an image processing apparatus 2 according to the present invention, and a plurality of radiation image display apparatuses 3 that display a radiation image connected via a network N. Yes.

  The radiation imaging apparatus 1 is an apparatus that receives radiation transmitted through a subject and generates a radiation image having a signal value proportional to the logarithm of the received radiation amount. Radiation image generation devices with various configurations such as devices using sensors and cassettes equipped with a stimulable phosphor plate and reading the stimulable phosphor plate to generate a radiation image are used. be able to. In addition, these devices include a standing device that generates radiation images by irradiating a patient (subject) in a standing position with radiation (positioning of the subject) between the subject and the detector, and a patient in a lying position. There is a supine device that generates radiation images by irradiating with radiation. Further, in the case of a cassette photographing apparatus that uses a cassette, the arrangement of the subject and the detector is not fixed, and the detector can be freely arranged with respect to the subject. The type of radiation imaging apparatus 1 and the number connected to the network N are not particularly limited.

  In either apparatus, a signal value proportional to the logarithm of the radiation amount transmitted through the subject irradiated on the detector is obtained, and the signal value increases as the irradiation amount increases.

  For example, when the imaging region is the front of the patient's abdomen, as shown in FIG. 2A, when imaging is performed with a standing device, the soft tissue such as the patient's muscles and fat is in the direction of the legs (arrow P). Direction), and tends to be biased toward the chest and lower abdomen (region A). On the other hand, when radiographic images of the same patient are taken with the prone device on the front of the abdomen, which is the same part, the soft tissue of the patient can easily move to the flank side (arrow Q direction) as shown in FIG. Soft tissue tends to be biased toward the flank (region B).

  Therefore, when the image taken with the standing device is compared with the case imaged with the standing device, the soft tissue thickness is increased in the standing device, and the soft tissue thickness is reduced in the standing device. . In this way, the movement characteristics of the soft tissue of the subject change due to the positioning of the subject, and thus the thickness of the soft tissue is different, and even if the same part of the same patient is obtained by the radiation imaging apparatus 1 used for imaging, it can be obtained. There is a difference between the signal value of the radiographic image data and the histogram that is the frequency distribution.

  As described above, the image processing apparatus 2 according to the present invention has a factor that affects the image quality of a radiographic image at the time of generating each data in a plurality of radiographic images generated by the radiographic apparatuses 1 having different configurations ( (Hereinafter referred to as “image quality influencing factor”), image processing conditions to be applied to each radiographic image data are determined. As shown in FIG. 4, a control unit 21, a storage unit 22, an I / F unit 23, an image processing unit 24, and these units are connected to each other via a bus 25.

  The control unit 21 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. In the CPU, a predetermined area of the RAM is stored as a work area in the ROM or the storage unit 22. In accordance with various programs, a control signal is sent to each of the above parts by computer control to centrally control the overall operation of the image processing apparatus 2, and image processing algorithm determination processing, region of interest determination processing, image processing condition determination processing, image processing, etc. described later are performed. Perform various processes.

  The storage unit 22 includes a magnetic or optical storage medium such as an HDD (Hard Disc Drive) or an optical disk, or a storage medium (not shown) such as a semiconductor memory, which is fixed or detachable, and includes an image processing algorithm determination program, a region of interest In addition to various programs related to the image processing apparatus 2 such as a determination program, an image processing condition determination program, and an image processing program, various data used when executing these processing programs are stored.

  The I / F unit 23 is a network interface for communication connection with the radiation imaging apparatus 1 and the radiation image display apparatus 3 through the network N, and exchanges various data such as radiation image data between these apparatuses.

  The image processing unit 24 determines an image processing algorithm or / and an image processing condition to be applied to the radiographic image data based on the image quality affecting factor, and performs radiation according to the determined image processing algorithm or / and the image processing condition. The image data is subjected to image processing. Radiation image data analysis means 24a, image processing algorithm determination means 24b, region of interest determination means 24c, reference signal determination means 24d, image processing condition determination means 24e, image processing condition factor generation means 24f has image processing means g.

  Here, as the image quality affecting factor, specifically, the direction of the detector with respect to the subject, the distance between the subject and the detector, the positioning of the subject, the presence or absence of a scatterer interposed between the subject and the detector, etc. And the ratio of the scattered radiation removal grid used in each radiographic apparatus.

  For example, if the orientation of the detector relative to the subject at the time of generating the radiographic image data is different, the image reading direction will be different from the orientation of the subject. Affects the image quality.

  Further, when the distance between the subject and the detector is increased, the captured radiographic image is enlarged, and the degree of scattering of the radiation applied to the detector is increased. Further, when the degree of scattering increases, the image quality is affected, for example, the sharpness of the radiographic image decreases. Further, in the cassette photographing apparatus, since the arrangement of the detector with respect to the subject can be freely changed, the distance between the subject and the detector varies. Thus, if the distance between the subject and the detector is different, the image quality of the radiation image is affected.

  As described above, the moving characteristics of the soft tissue of the subject change due to the positioning of the subject, and this affects the image quality of the generated radiographic image.

  Examples of the scatterer interposed between the subject and the detector include a photo timer and a mat for reducing the physical load on the patient. If the detector detects a scattered ray in which the radiation transmitted through the subject is scattered by these scatterers, the sharpness of the generated radiation image is lowered.

  The scattered radiation removal grid is fixed for each radiation imaging room in which each radiation imaging apparatus is installed, and the grid ratio may differ depending on each radiation imaging room. The grid ratio is determined by the number of grids arranged vertically and horizontally. The higher the grid ratio, the more scattered rays that are removed. Therefore, the magnitude of the grid ratio also affects the quality of the radiation image.

  The image processing unit 24 determines the image processing algorithm and the image processing conditions based on these image quality influencing factors, thereby removing the influence on the image quality of each radiation image by these image quality influencing factors and stabilizing the image quality. It is what I did.

  The image processing algorithm includes information necessary for image processing, such as a method of setting a region of interest described later and a method for determining a reference signal value necessary for generating an image processing condition factor. How to make a decision is included.

  The image processing conditions include a gradation conversion curve (line segment) (LUT: Look Up Table) used for gradation processing, an enhancement function used for frequency processing, and dynamic range compression processing. Including conditions relating to various types of image processing applied to radiographic image data, such as a correction function used in the above.

  In the present invention, both the image processing algorithm and the image processing condition may be determined based on the image quality affecting factor at the time of generating the radiographic image data. Either the image processing algorithm or the image processing condition may be used. May be configured in advance.

Hereinafter, each unit in the image processing unit 24 will be described.
The radiation image data analyzing unit 24a analyzes the data of the radiation image to be image processed, and acquires information on the various image quality affecting factors and information on the imaging region of the subject on which the radiation image appears.

  In addition, when analyzing radiographic image data, if the information on the image quality affecting factor and the information on the imaging region of the subject on which the radiographic image appears are incidental to the radiographic image data, use them. Can do.

  In addition, the radiation imaging apparatus 1 that has generated the data by analyzing the data of the radiographic image by previously storing the feature quantity of each radiography apparatus 1 and each radiation imaging apparatus 1 in the storage unit 22 or the like. And information related to the various image influencing factors associated therewith may be read from the storage unit 22.

  In the radiographic image data analysis means 24a, when analyzing radiographic image data, an irradiation field recognition process for discriminating between the irradiation field area and the irradiation field area in the radiation image data may be performed as necessary. .

  As this irradiation field recognition, for example, a method disclosed in Japanese Patent Laid-Open No. 63-259538 is used, and image data on a line segment from a predetermined position on the imaging surface toward the end side of the imaging surface is used. For example, differentiation processing is performed. Since the differential signal obtained by this differentiation process has a signal level that is large at the irradiation field edge portion, one signal field edge candidate point is obtained by determining the signal level of the differential signal. A plurality of irradiation field edge candidate points are obtained by performing the process of obtaining the irradiation field edge candidate points radially about a predetermined position on the imaging surface. An irradiation field edge portion is obtained by connecting a plurality of irradiation field edge candidate points obtained in this way with straight lines or curves.

  Moreover, the method shown by Unexamined-Japanese-Patent No. 5-7579 can also be used. In this method, when the imaging surface is divided into a plurality of small areas, the radiation dose of the radiation is reduced substantially uniformly in the small areas outside the irradiation field where radiation irradiation is blocked by the irradiation field stop. Becomes smaller. In addition, in a small region within the irradiation field, the radiation value is modulated by the subject, so that the dispersion value is higher than that outside the irradiation field. Further, in a small region including the irradiation field edge portion, the portion with the smallest radiation dose and the portion with the radiation dose modulated by the subject coexist, so the dispersion value is the highest. From this, the small area including the irradiation field edge portion is determined by the dispersion value.

  Moreover, the method shown by Unexamined-Japanese-Patent No. 7-181609 can also be used. In this method, image data is rotated about a predetermined center of rotation, and rotation is performed until the boundary line of the irradiation field becomes parallel to the coordinate axis of the orthogonal coordinates set on the image by the parallel state detection means. When the state is detected, the linear equation of the boundary before rotation is calculated by the linear equation calculation means based on the rotation angle and the distance from the rotation center to the boundary line. Thereafter, by determining a region surrounded by a plurality of boundary lines from a linear equation, the region of the irradiation field can be determined. When the irradiation field edge portion is a curve, for example, one boundary point is extracted based on the image data by the boundary point extraction means, and the next boundary point is extracted from the boundary candidate point group around this boundary point. Similarly, by sequentially extracting boundary points from the boundary candidate point group around the boundary points, it is possible to determine whether the irradiation field edge portion is a curve.

  By performing irradiation field recognition processing and performing image processing using the radiation image data in the subject area and the radiation image data in the irradiation field area, images such as level conversion processing and subsequent gradation processing are performed. In the processing, the data of the radiation image outside the subject region or the irradiation field is not used, so that the image processing of the part required for diagnosis can be performed appropriately.

  The reason why the irradiation field region and the irradiation field region are generated in the radiographic image data is as follows. When taking a radiographic image, for example, in order to prevent radiation from being applied to a portion that is not required for diagnosis, or to a portion that is not required for diagnosis, radiation scattered in this portion is required for diagnosis. In order to prevent the resolution from being reduced by being incident on the target area, a radiation non-transparent material such as a lead plate is installed on a part of the subject or radiation generator to limit the radiation field on the subject. This is because the aperture is performed.

  The image processing algorithm determination unit 24b determines an algorithm to be used for determining a region of interest ROI to be described next, based on the image quality influence factor analyzed by the radiation image data analysis unit 24a. The image processing algorithm determination means 24b is not limited to the algorithm used for determining the region of interest to be set, and may be configured to determine an algorithm used for determining a reference signal range or a reference signal described later. .

For example, when a frontal image of the abdomen is taken with the standing device and the standing device, it is recognized whether the image is taken with the standing device or the lying device and prepared in advance. It is possible to use a separate image processing algorithm.
At this time, if the apparatus information is attached to the radiographic image data as the supplementary information, it can be read to recognize which apparatus is used, and information is input according to image processing parameters. This makes it possible to recognize the device. Note that the image processing algorithm includes various processing algorithms used when image processing is performed on radiation image data.

  In addition, when multiple processing algorithms are prepared, it is possible to determine which algorithm is used for processing, as in this case, depending on the device used for shooting, or shooting conditions such as the relationship between the subject and the detector Depending on the image processing condition determining factor, a method of dividing the image processing method may be used.

  Also, it is not necessary to prepare completely different processing algorithms, and any processing algorithm may be used as long as it includes a portion that varies depending on the above factors. In short, the algorithm to be used may be determined based on factors that affect the image quality of the radiographic image when generating the radiographic image data.

  For example, in the case of abdominal front processing, when setting a region of interest when performing image processing on radiographic image data, predetermined amounts a and d serving as threshold values are set as described below in the region of interest determination means 24c (described later). It is conceivable to prepare such a processing algorithm and use a processing algorithm suitable for each apparatus used for radiographic image capturing.

  For example, in the case of an abdominal front image taken with a standing device, the difference in profile values created in each region is less because the soft tissue is more biased than the image taken with the standing device. It becomes difficult to find the threshold values a and d as compared with the image photographed by the positioning device.

For this reason, when the image is taken with the standing device, the region of interest is determined in the same manner as with the supine position by setting the predetermined amounts a and d, which are the threshold values, smaller than those when the image is taken with the supine device. .
For example, if the predetermined amounts a and d are 50 and 120, respectively, when the image is taken with the standing device, the predetermined amounts a and d are set to 40 and 110, respectively, when the image is taken with the standing device. good.

  The region-of-interest determination unit 24c performs region-of-interest determination processing for determining which region of interest to set in accordance with the algorithm determined by the image processing algorithm determination unit 24b.

  In the region-of-interest determination process, first, a region to be noted for diagnosis is set according to the imaging region of the subject analyzed based on the analysis result of the radiographic image data. As a method for setting a region to be noted for diagnosis, for example, a method for recognizing a specific anatomical structure of a human body as a reference is used.

  For example, the abdominal front image taken by the standing device shown in FIG. 2A and the abdominal front image taken by the supine device shown in FIG. 3A are based on the pelvis, vertebrae, flank line, etc. As shown in FIG.

  Next, a region in the region C that is focused on for diagnosis and is less likely to be affected by the above factors in the radiographic image data is determined as the region of interest ROI.

  For example, when a radiographic image of the front of the abdomen of the same patient is captured with the standing device and the standing device, the region of interest ROI to be set is the soft tissue of the subject due to the relationship between the subject and the detector (positioning of the subject). Areas that are not easily affected by movement characteristics, that is, the soft tissue area around the 3rd lumbar spine to the 4th lumbar vertebrae, and the soft tissue in the flank that seems to be greatly affected by the movement of soft tissues such as fat and muscle Not decided on the area.

  More specifically, for example, as shown in FIGS. 2B and 3B, when a rectangular region of interest ROI is set in the abdomen front view, for example, the ROI lower end, the ROI upper end, and the ROI left end In terms of the right end of the ROI, the lower end of the ROI is the iliac bone in both the radiographic image taken with the standing device (FIG. 2B) and the radiographic image taken with the supine device (FIG. 3B). The upper end is the reference, the ROI upper end is based on the position of the height of 4 vertebrae from the upper end of the iliac bone, and the ROI left end and ROI right end should each be set as a region D that does not include the flank line Determined as ROI of interest.

  Here, with reference to FIGS. 5, 6, and 7, specific methods of setting the ROI lower end, upper end, left end, and right end will be described in order.

The following methods are conceivable for detecting the iliac upper end when setting the ROI lower end.
First, a region that is supposed to include the iliac bone is specified in the abdominal front image. For example, in the case of a frontal image of the abdomen, the upper end of the iliac is the lower half of the irradiation field vertical width with a very high probability, and the left region, the right Since this region is often located in a region that applies to this region, this region is designated as the iliac upper end detection region E (FIG. 5A).

  Next, as shown in FIG. 5B, a vertical profile is created in the iliac upper end detection region, and the amount of change in the profile value is confirmed in a certain direction. Among these, the point where the threshold value a set as a predetermined amount is exceeded for the first time (see FIG. 5C) is recognized as the upper end of the iliac and determined as the lower end of the ROI (see FIG. 5D). Here, the threshold value a may be set to a fixed value by the image processing parameter, or the value determined by the image processing parameter is detected as the threshold value a only at the first detection, and the amount of change as the threshold value a is not seen. In this case, a threshold value a ′ that automatically changes as appropriate may be set, or the upper end of the iliac bone may be set at a position where the profile value has changed the largest in the detection range without setting the threshold value a.

Next, the following methods are conceivable for detecting the position of the height of four vertebrae from the iliac upper end when determining the ROI upper end.
First, the horizontal profile is calculated in the irradiation field region, and the minimum value b and the column c that gives it are defined as the approximate spine lines. The profile creation range F is a range from the right end to the left end of the irradiation field in the horizontal direction and from the upper third of the irradiation field to the center of the irradiation field in the vertical direction (FIG. 6A). Columns e and f whose profile values on the left and right of column c are larger than b by a predetermined amount d (see FIG. 6C) are obtained (see FIG. 6B), and the distance between e and f is the width of one vertebra Consider g. Then, 0.6 times the lateral width g of one vertebra is defined as a vertical width h (not shown) of one vertebra. Next, the ROI upper end is defined as the position where the height of four vertebrae, that is, the height of four vertebrae is four times the vertical width h from the position of the lower end of ROI obtained above (FIG. 6). (See (D)). The predetermined amount d can be set by an image processing parameter, or can be changed for each image in consideration of characteristics of the image such as an average of pixel values in the entire irradiation field.

Next, the following methods are conceivable for detecting the position of the flank that does not include the flank line when determining the left and right ends of the ROI.
In the region G between the ROI upper end and lower end determined previously (FIG. 7A), a profile is created in the horizontal direction, and the maximum profile value i and the minimum profile value j are determined (FIG. 7B )reference). Next, columns m and m ′ that give l corresponding to a signal value of a predetermined ratio k of the difference between i and j are obtained in the left and right regions of the irradiation field, and the positions are determined as the ROI left end and the ROI right end (FIG. 7 ( c)).
The predetermined ratio k can be set by an image processing parameter, or can be changed for each image in consideration of the characteristics of the image such as the average of the pixel values in the entire irradiation field.

  In this way, when there is a difference in the signal value distribution of the acquired radiographic image data due to factors affecting the image quality of the radiographic image at the time of generating the radiographic image data, By setting a region that is not affected by such factors as the region of interest, a similar signal value distribution can be obtained from the data of the radiation image included in the region of interest. Due to the difference in configuration, it is possible to suppress variations in image quality that also appear for the same part of the same patient.

  Next, a histogram normalization and reference signal value determination method in the reference signal determination unit 24d will be described.

  First, two reference signal values D1, which are representative values from a cumulative histogram obtained by statistically analyzing the data of the radiographic image included in the region of interest ROI set by the region of interest determination means 24c, the reference signal Set the value D2. Here, the reference signal values D1 and D2 can be set, for example, as levels (signal values) of image data (pixels) at which the cumulative histogram has a predetermined ratio.

Next, the image processing condition determination unit 24e will be described.
The image processing condition determining unit 24e obtains a gradation conversion curve based on the reference signal values D1 and D2 set by the reference signal determining unit 24d. For example, as shown in Japanese Patent Publication No. 5-26138, it is assumed that a plurality of basic gradation conversion curves are stored in advance, and any of the basic gradation conversion curves is read out and rotated and translated. The tone conversion curve can be easily obtained.

  For example, when a standing device and a standing device are used as the radiation imaging device to be used, a gradation suitable for each of the images photographed by the standing device on the basis of the radiation image generated by the standing device When determining a curve, the following methods can be considered.

  The image taken with the standing device and the image taken with the supine device have a difference in the soft tissue bias of the subject as described above (see FIGS. 2 and 3), so the soft tissue thickness is compared. In an image taken with a standing device, an amount of radiation reaching the detector in each part is biased with respect to an image taken with a uniform lying device, resulting in a difference in density between the low density part and the high density part. As a result, the generated radiation image tends to be a high-contrast image.

The density of the low density part and the high density part can be set by image processing parameters as the density DL and DH for setting the output density of the reference signal values D1 and D2.
For example, in an image taken with a standing device, the difference between the densities DL and DH may be set to be 0.1 larger than the difference between DL and DH of the image taken with a standing device.

  Next, the image processing condition factor generation unit 24f will be described. Here, parameters used in frequency enhancement processing and dynamic range compression processing for correcting variations in image quality due to differences in subject and detector arrangement, distance, grid ratio, and the like are set.

  In the frequency enhancement process, for example, the function F is determined by a method shown in Japanese Patent Publication Nos. 62-62373 and 62-62376 in order to control the sharpness by the non-sharp mask process shown in the equation (1).

Soua = Sorg + F (Sorg−Sus) (1)
In Equation (1), Soua is the processed data, Sorg is the radiographic image data before the frequency enhancement process, and Sus is the non-obtained value obtained by averaging the radiographic image data before the frequency enhancement process. It is sharp data.

  In this frequency emphasis processing, for example, F (Sorg-Sus) is set to β × (Sorg-Sus), and β (enhancement coefficient) is approximately linear between the reference values T1 and T2 as indicated by a solid line in FIG. Changed. Further, as shown by the solid lines in FIG. 9, when values A and B are set and low luminance is emphasized, β from the reference value T1 to the value A is maximized, and from the value B to the reference value T2. Minimized.

  In addition, from value A to value B, β changes substantially linearly. When emphasizing high luminance, as indicated by a broken line, β from the reference value T1 to the value A is minimized and maximized from the value B to the reference value T2. In addition, from value A to value B, β changes substantially linearly. Although not shown, when medium luminance is emphasized, β of values A to B is maximized. As described above, in the frequency enhancement process, the sharpness of an arbitrary luminance portion can be controlled by the function F.

  Further, the frequency enhancement processing method is not limited to the non-sharp mask processing, and a technique such as a multi-resolution method disclosed in JP-A-9-44645 may be used. In frequency emphasis processing, the frequency band to be emphasized and the degree of emphasis are set based on the imaging region, imaging position, imaging conditions, imaging method, etc., as in the selection of the basic gradation curve in gradation processing. The

By setting the emphasis coefficient of the frequency emphasis processing to an appropriate value by the processing parameter, the problems as recited in claims 6, 7, 8, 17, 18, and 19 can be solved.
Specific examples are shown below.

  As in claims 6 and 17, when the distance between the subject and the detector is large, the amount of scattered radiation increases and the contrast tends to be lower than when the distance between the subject and the detector is short.

Thus, in the case where the distance between the subject and the detector is large as described above, for example, a method of increasing the appearance contrast of the image by increasing the enhancement coefficient β of the frequency enhancement process included in the image processing parameter can be considered.
On the other hand, when the distance between the subject and the detector is close, the amount of scattered radiation is smaller than when the distance between the subject and the detector is far away, so that the contrast tends not to decrease.

Therefore, when the distance between the subject and the detector is close, a method of preventing the contrast from becoming too high by reducing the enhancement coefficient β can be considered.
For example, if it is considered that the distance between the subject and the detector is 2 to 10 cm, the enhancement coefficient β when the distance is 2 cm is set to 0.3 on both the low frequency side (β1) and the high frequency side (β2). If the distance is increased, β is increased as the distance increases, and the enhancement factor (β1) on the low frequency side and the enhancement factor (β2) on the high frequency side are set to about 0.32 to 0.40, respectively. good.

  In the case where a scatterer is interposed between the subject and the detector as in claims 7 and 18, the amount of scattered radiation is larger than in the case where the scatterer is not included between the subject and the detector, so the contrast is reduced. Have a tendency to.

Accordingly, in the case where the scatterer is interposed between the subject and the detector as described above, for example, a method of increasing the enhancement coefficient β of the frequency enhancement process included in the image processing parameter and increasing the apparent contrast of the image can be considered.
On the contrary, when the scatterer is not included between the subject and the detector, the amount of scattered radiation is small compared to the case where the scatterer is interposed between the subject and the detector, so that the contrast tends not to decrease.

Therefore, in the case where a scatterer is not included between the subject and the detector, a method of preventing the contrast from becoming too high by reducing the enhancement coefficient β can be considered.
For example, if a photo timer is interposed between the subject and the detector, and the enhancement coefficient β without the photo timer is set to 0.3 on both the low frequency side (β1) and the high frequency side (β2), The low frequency side enhancement coefficient (β1) and the high frequency side enhancement coefficient (β2) may be set to about 0.35, respectively.

  As in claims 8 and 19, when the grid ratio used is small, the amount of scattered radiation increases compared to when the grid ratio is large, and the contrast tends to decrease.

Accordingly, when the grid ratio to be used is small, for example, a method of increasing the enhancement factor β of the frequency enhancement process included in the image processing parameter and increasing the visual contrast of the image can be considered.
Conversely, when the grid ratio used is large, the amount of scattered radiation is smaller than when the grid ratio used is small, so that the contrast tends not to decrease.

  Therefore, when the grid ratio used is large, a method of preventing the contrast from becoming too high by reducing the enhancement coefficient β can be considered.

For example, when shooting is performed using a grid having a grid ratio of 1: 8 and a grid ratio of 1:12, an image shot using a grid having a grid ratio of 1: 8 is 1:12. The amount of scattered radiation is larger than images taken using the grid.
For this reason, for example, if the original enhancement coefficient β is set to 0.3 on both the low frequency side (β1) and the high frequency side (β2) when using either grid, a 1: 8 grid is obtained. When shooting using the low frequency side enhancement coefficient (β1) and high frequency side enhancement coefficient (β2) are set to about 0.35, respectively, and when shooting using a 1:12 grid, The enhancement factor (β1) on the low frequency side and the enhancement factor (β2) on the high frequency side may be set to about 0.3, respectively.

Next, dynamic range compression processing will be described.
In the dynamic range compression process, the function G is determined by the method shown in Japanese Patent Publication No. 266318 in order to control the density range to be easy to see by the compression process shown in Equation (2).

Stb = Sorg + G (Sus) (2)
In equation (2), Stb is the image data after processing, Sorg is the data of the radiation image before the dynamic range compression processing, and Sus is the data of the radiation image before the dynamic range compression processing by averaging processing or the like. Unsharp data.

  Here, as shown in FIG. 10A, G (Sus) has a characteristic such that G (Sus) increases when the unsharp data Sus becomes smaller than the level La. The image data Sorg shown in FIG. 10B is image data Stb in which the dynamic range on the low density side is compressed as shown in FIG. 10C.

  Further, as shown in FIG. 10D, when G (Sus) has such characteristics that G (Sus) decreases when the unsharp data Sus becomes smaller than the level Lb, as shown in FIG. The density is high, and the dynamic range on the high density side of the image data Sorg shown in FIG. 10B is compressed as shown in FIG. In the dynamic range compression processing, the correction frequency band and the degree of correction are set based on the imaging region, the imaging posture, the imaging conditions, the imaging method, and the like.

  Here, the reference values T1 and T2 and the values A and B or the levels La and Lb, which are processing conditions in the frequency emphasis processing and dynamic range compression processing described above, are obtained by a method similar to the method for determining the representative values D1 and D2. .

  In these cases, it is possible to have shielding area display means for displaying the shielding area that is input or recognized. According to this, an operator can perform processing while confirming the position by displaying the shielding area which is not substantially irradiated with radiation.

  The image processing unit 24g generates the image processing condition generated by the image processing condition factor generation unit 24f based on the image processing condition determined by the image processing condition determination unit 24e and the image processing parameter generated by the image processing condition generation unit 24f. According to the factor (image processing parameter), the radiographic image data that is the original image transmitted from the radiation imaging apparatus 1 has the image quality due to the difference in the imaging apparatus, the difference in the distance between the detector and the subject, and the difference in the grid ratio used for imaging. Image processing for correcting variation is performed to obtain a final output image.

  Here, correcting the image quality variation is to suppress the difference in contrast, density, and sharpness as the image quality variation described above by changing the image processing parameter including the enhancement coefficient β of the frequency enhancement processing. .

  In the image processing unit 24 described above, when image processing is performed on data of a plurality of radiographic images in order to obtain a plurality of radiographic images for comparative interpretation, radiation generated by any one radiographic apparatus is used. It is preferable that an image processing algorithm and image processing conditions reflecting the influence of the above factors are determined for each radiographic image data on the basis of image data.

  Further, the image processing device 2 is provided with an image compression unit, generates a compressed image in which the number of pixels is thinned out from the data of the radiographic image acquired through the I / F unit 23, and the image processing unit 24 uses this compressed image. The above-described series of processing until the image processing conditions are determined may be performed. When a compressed image is used, the amount of data is reduced, so that the processing speed when determining image processing conditions can be improved, and the memory capacity can be reduced.

  The radiation image display device 3 is, for example, a terminal device installed in an examination room or the like, and includes a display device such as a CRT (Cathode Lay Tube) or an LCD (Liquid Crystal Display). The interpreting doctor interprets the data of the radiographic image subjected to the image processing by the image processing apparatus 2 as a visible radiographic image by using the radiographic image display device 3, and examines the patient.

  In the radiographic image display device 3, when displaying the data of the radiographic image subjected to image processing, together with the display of the radiographic image or the processed image, information on the region of interest, information on the image processing condition factor, or the image processing condition Information related to this may be displayed.

  As a result of such display, by displaying the region of interest that has an important effect on image processing, image processing condition factors, and image processing conditions, an accurate and optimal image processing image can be obtained, and the interpretation doctor Can contribute to providing useful information for diagnosis.

  Of course, the number of radiation image display devices 3 connected to the network N is not limited.

  As described above, in the best mode for carrying out the present invention, the image processing apparatus 2 includes the image processing algorithm determination unit 24b and the image processing condition determination unit 24e, and is a factor that affects the image quality at the time of data generation of the radiation image. Based on this, the image processing algorithm and the image processing conditions are determined, and the image processing is performed on the radiographic image data in accordance with them. Therefore, the optimum image processing conditions excluding the influence of the above factors can be obtained, and there is no complicated operation. In addition, it is possible to automatically obtain an optimal image for diagnosis.

  In the best mode, the region-of-interest determination means 24c sets a region where the influence of the factor is less likely to appear as a region of interest, and generates an image processing condition factor based on the radiographic image data included in the region of interest. It is possible to obtain optimal image processing conditions excluding the influence of the image quality of a radiographic image generated by using a radiation imaging apparatus having a different configuration, and automatically obtain an optimal image for diagnosis without complicated operations. It becomes possible.

  In the best mode described above, the relationship between the subject and the detector, the movement characteristics of the soft tissue of the subject resulting from this, the distance between the subject and the detector, the direction of the detector relative to the subject, and the interposition between the subject and the detector The optimum image processing conditions are determined in consideration of factors that affect the image quality of the radiographic image at the time of data generation, such as the presence or absence of scatterers and the grid ratio of the grid used when generating the radiographic image data. Even when a plurality of radiation image data is generated using radiation imaging apparatuses having different configurations, it is possible to correct variations in the image quality of each radiation image caused by these factors and is optimal for diagnosis without complicated operations. Images can be obtained automatically.

  Therefore, even when the same part of the same subject is imaged, it is possible to correct the variation in image quality that occurs between the data of each radiographic image generated by using the radiographic apparatus having a different configuration. Furthermore, at this time, by determining an image processing algorithm, image processing conditions, etc. on the basis of any one of the radiographic images, for example, radiographic image data that is optimal for diagnosis, radiographic imaging of other configurations A radiographic image taken using the apparatus 1 can also be an image most suitable for diagnosis, and comparative interpretation is facilitated.

  It should be noted that the present invention is not limited to the above-described best mode, and can of course be changed as appropriate without departing from the spirit of the present invention. For example, the image processing apparatus 2 according to the present invention is embodied in the image processing system 100, but is not limited thereto. The image processing apparatus 2 may be directly connected to each radiation imaging apparatus 1 or may be configured to read the radiation image data recorded on various recording media and perform image processing on the radiation image data.

1 is a diagram illustrating a configuration of an image processing system including an image processing apparatus according to an example of the present invention. FIG. 5A is a diagram showing a movement characteristic of a soft tissue of a subject when imaged by a standing apparatus, and FIG. 5B is a diagram showing a region of interest to be set. FIG. 5A is a diagram showing a movement characteristic of a soft tissue of a subject when imaged by a prone device, and FIG. 5B is a diagram showing a region of interest to be set. It is a block diagram which shows the functional structure of the image processing apparatus of an example of this invention. It is a figure which shows the specific ROI lower end setting method of abdominal front process. It is a figure which shows the specific ROI upper end setting method of abdominal front process. It is a figure which shows the specific ROI right-and-left end setting method of abdominal front process. It is explanatory drawing which shows the emphasis coefficient and radiographic image data in the best form for implementing this invention. It is explanatory drawing which shows the emphasis coefficient and radiographic image data in the best form for implementing this invention. It is explanatory drawing which shows the dynamic range compression in the best form for implementing this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiography apparatus 2 Image processing apparatus 24 Image processing part 24a Radiation image data analysis means 24b Image processing algorithm determination means 24c Region of interest determination means 24d Reference signal determination means 24e Image processing condition determination means 24f Image processing condition factor generation means 24g Image processing Means 100 Image Processing System ROI Region of Interest

Claims (22)

In an image processing apparatus that performs image processing on data of a plurality of radiation images generated by radiation imaging apparatuses having different configurations,
An image processing condition determining unit that determines an image processing condition for performing the image processing based on a factor that affects the image quality of the radiographic image when the radiographic image data is generated by the radiographic apparatus. An image processing apparatus. In an image processing apparatus that performs image processing on data of a plurality of radiation images generated by radiation imaging apparatuses having different configurations,
The image processing algorithm determining means for determining an image processing algorithm for performing the image processing based on a factor affecting the image quality of the radiation image when the radiation image data is generated by the radiation imaging apparatus. An image processing apparatus. The image processing apparatus according to claim 2,
Based on the image processing algorithm, a region-of-interest determining means for determining a region in which the influence of the factor is unlikely to appear in the data of the radiation image as a region of interest;
Image processing condition determining means for determining an image processing condition when performing the image processing based on the data of the radiation image included in the region of interest determined by the region of interest determining means;
An image processing apparatus comprising: In the image processing device according to any one of claims 1 to 3,
The image processing apparatus according to claim 1, wherein the factor includes an arrangement relationship between a subject and a detector that is provided in the radiation imaging apparatus and detects a radiation amount transmitted through the subject. The image processing apparatus according to claim 4.
The image processing apparatus according to claim 1, wherein the factor includes a movement characteristic of a soft tissue of a subject according to an arrangement relationship between the detector and the subject. The image processing apparatus according to claim 4.
The image processing apparatus according to claim 1, wherein the factor includes a distance between the detector and the subject. The image processing apparatus according to claim 4.
The image processing apparatus according to claim 1, wherein the factor includes the presence or absence of a scatterer interposed between the detector and the subject. In the image processing device according to any one of claims 1 to 7,
The image processing apparatus according to claim 1, wherein the factor includes a grid ratio of a grid for removing scattered radiation used when generating data of the radiation image. In the image processing device according to any one of claims 1 to 8,
The image processing apparatus is characterized in that the image processing is performed in order to correct a variation in image quality that occurs between data of a plurality of radiation images due to the factor. In the image processing device according to any one of claims 1 and 3-9,
The image processing condition determining means determines the image processing condition with reference to radiation image data generated by any one of the radiation imaging apparatuses having different configurations. apparatus. The image processing apparatus according to claim 2 or 3,
The image processing algorithm determining means determines the image processing algorithm on the basis of radiation image data generated by any one of the radiation imaging apparatuses having the different configurations. apparatus. In a computer for executing image processing on data of a plurality of radiation images generated by radiation imaging apparatuses having different configurations,
An image for realizing an image processing condition determination function for determining an image processing condition when performing the image processing based on a factor that affects the image quality of the radiographic image when the radiographic image data is generated by the radiographic apparatus. Processing program. In a computer for executing image processing on data of a plurality of radiation images generated by radiation imaging apparatuses having different configurations,
An image for realizing an image processing algorithm determination function for determining an image processing algorithm when performing the image processing based on a factor that affects the image quality of the radiation image when the radiographic image data is generated by the radiation imaging apparatus Processing program. The image processing program according to claim 13,
A region-of-interest determination function that determines, as a region of interest, a region in which the influence of the factor is less likely to appear in the radiographic image data, based on the image processing algorithm for causing the computer to realize
An image processing condition determination function for determining an image processing condition when performing the image processing based on data of the radiation image included in the region of interest determined by the region of interest determination means;
An image processing program comprising: In the image processing program as described in any one of Claims 12-14,
An image processing program characterized in that the factor includes an arrangement relationship between a subject and a detector that is provided in the radiation imaging apparatus and detects a radiation amount transmitted through the subject. The image processing program according to claim 15,
An image processing program characterized in that the factor includes a movement characteristic of a soft tissue of a subject according to an arrangement relationship between the detector and the subject. The image processing program according to claim 15,
An image processing program characterized in that the factor includes a distance between the detector and the subject. The image processing program according to claim 15,
An image processing program characterized in that the factor includes the presence or absence of a scatterer interposed between the detector and the subject. In the image processing program according to any one of claims 12 to 18,
An image processing program characterized in that the factor includes a grid ratio of a grid for removing scattered radiation used when generating data of the radiation image. In the image processing program according to any one of claims 12 to 18,
The image processing program, wherein the image processing is performed in order to correct a variation in image quality that occurs between data of a plurality of radiation images due to the factor. In the image processing program according to any one of claims 12, 14 to 20,
The image processing condition determining means determines the image processing condition with reference to radiation image data generated by any one of the radiation imaging apparatuses having different configurations. program. The image processing program according to claim 13 or 14,
The image processing algorithm determining means determines the image processing algorithm on the basis of radiation image data generated by any one of the radiation imaging apparatuses having the different configurations. program.

Images