JPH0678910A - Radiation image processor - Google Patents

Abstract

PURPOSE:To avoid re-photographing wastefully when any defect is compensated by image processing to obtain good image data even if a photographing condition is defective, by detecting the data showing the distribution condition of image data after image processing, and discriminating the quality of image data after processing according to the detection results. CONSTITUTION:A histogram creating part 13 of an image judging device creates a histogram for analyzing the distribution condition of image data gradation- processed by a gradation processing part 11 of an image processor 8. A histogram analyzing part 14 analyzes the histogram created by the creating part 13 to obtain the data showing the distribution condition of the image data, and the data is output to a quality judging part 15. Subsequently, the judging part 15 compares the data showing the distribution condition with a preset expected value, and according to the comparison result, the quality of image data output from the processing part 11 is judged. When it is judged to be defective, a re-processing condition deciding part 17 decides a re-processing condition, and according to the decided re-processing condition, a re-processing part 18 re-processes image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image processing apparatus, and more particularly to a technique for comprehensively determining the quality of the results of imaging and image processing when image processing is performed on the image data of the radiation image. .

[0002]

2. Description of the Related Art Radiation images such as X-ray images are often used for diagnosing diseases, etc. In order to obtain this X-ray image, X-rays transmitted through a subject are applied to a phosphor layer (fluorescent screen). Conventionally, so-called radiography, in which visible light is generated by irradiation, and the visible light is applied to a film using a silver salt to develop the film, which is the same as in ordinary photography, has been conventionally used.

However, in recent years, a method for directly taking out an image from a phosphor layer has been devised without using a film coated with a silver salt. For this method,
Radiation that has passed through the subject is absorbed by the phosphor, and then the phosphor is excited by, for example, light or thermal energy to cause the phosphor to emit the radiation energy accumulated by the absorption as fluorescence. There is a method of obtaining an image signal by performing photoelectric conversion on the.

Specifically, for example, US Pat. No. 3,859,527 and JP-A-55-12144 disclose a radiation image conversion method using a stimulable phosphor and using visible light or infrared light as stimulated excitation light. ing. This method uses a radiation image conversion panel having a stimulable phosphor layer formed on a support.
Radiation that has passed through the subject is applied to the photostimulable phosphor layer of this conversion panel to accumulate the radiation energy corresponding to the radiation transmittance of each part of the subject to form a latent image, after which the photostimulable layer is stimulated. By scanning with excitation light, the accumulated radiation energy is emitted and converted into light, and this light signal is photoelectrically converted to obtain a radiation image signal.

The radiation image signal thus obtained is output as it is or after being subjected to image processing and output to a silver salt film, CRT or the like for visualization or filing in an electronic filing device. In the image processing, the purpose is to make the density of the region of interest (region including the image part necessary for medical diagnosis) constant in the reproduced image, and to output the shadows (region of interest) of the human body structure and lesions in a more visible manner. For this purpose, image processing such as gradation processing and spatial frequency processing is performed.

For example, in the radiation image processing apparatus disclosed in Japanese Patent Application Laid-Open No. 3-218578, an image signal is analyzed to determine a region of interest, and gradation processing conditions are automatically set based on the image signal in the region of interest. It is disclosed that the gradation process is performed after the determination, and by this, an output image with stable density and gradation can be automatically obtained, and the diagnostic performance can be improved.

[0007]

By the way, in the radiograph, the radiation dose and the tube voltage are adjusted according to the body shape of the patient and the part to be observed, etc., based on the know-how acquired by the photographer (radiologist). Then, the output image is faithfully reproduced as it is according to the adjustment result of the photographer.
However, there is a possibility that the shooting may fail due to the peculiarity of the patient's body shape or shooting mistakes, and the quality of the shooting is judged by visually observing the radiograph visualized by the development process
Depending on the result of this judgment, measures such as re-shooting were taken.

In this respect, in the case of a system for obtaining a radiation image signal by using the radiation image conversion panel, no development processing is required, and therefore, whether or not the photographing is good (improper photographing condition and / or reading condition) is performed on the spot. It is possible to determine immediately, and since image processing is performed after shooting and reading as an image signal,
It is also possible to obtain a desired image by compensating for the defective photographing condition and reading condition by image processing to some extent.

Further, in the system for obtaining the irradiation line image signal as described above, since the radiation image information is treated as an image signal, it is possible to automate the judgment of pass / fail. Therefore, an apparatus for automatically determining imaging failure from a radiographic image signal before image processing (see Japanese Patent Laid-Open No. 3-19090, etc.), and an apparatus for determining the reliability of image processing conditions determined from the image signal (Japanese Patent Laid-Open No. Hei 10-32100) No. 2-14376, etc.) is proposed, which makes it possible to independently judge the quality of shooting and image processing, and perform re-shooting and resetting of processing conditions.

However, even if the photographing (the photographing condition and / or the reading condition) and the image processing are independently performed as expected, the finally obtained image after the image processing is intended by the photographer. It may be different from the image. Also, if you try to reduce the fluctuation of the density by image processing, the contrast becomes low,
If image processing is performed with an emphasis on keeping the density of the entire image constant, the density of the target portion (region of interest) may become inappropriate.

As described above, even if the image quality (imaging conditions and / or reading conditions) and the image processing quality are individually determined, the actually obtained image-processed image is as intended by the photographer. However, if the radiographing and the image processing are directly performed based on the determinations that the radiographing and the image processing are successful, the diagnostic performance may be deteriorated when the radiation image is used for the actual diagnosis later.

Further, even when it is determined from the radiation image signal before the image processing that the imaging is defective, there are cases where the defect can be compensated by the image processing. If re-imaging is executed based on the determination, re-imaging and re-processing will be unnecessarily performed. The present invention has been made in view of the above problems, and obtains radiation image information as image data,
In a radiographic image processing apparatus that performs image processing on this, a series of steps of imaging, reading, and image processing are performed, and then an apparatus that can determine the quality of the obtained image information is provided. The purpose is to ensure that radiation image information (excellent in diagnostics) can be obtained.

It is another object of the present invention to obtain radiation image data for which a good judgment is made by reprocessing when a bad judgment is made by the good / bad judgment.

[0014]

Therefore, the radiation image processing apparatus according to the present invention is an image processing means for performing image processing on image data of a radiation image formed corresponding to the amount of radiation transmitted through each part of a subject. A distribution state detecting means for detecting data indicating a distribution state of image data subjected to image processing by the image processing means, data indicating a distribution state of the image data detected by the distribution state detecting means, It is configured to include a pass / fail determination unit that determines pass / fail of the image data processed by the image processing unit based on a comparison with a desired value of the data and outputs a pass / fail determination signal.

Here, the image processing means analyzes the image data of the radiation image formed corresponding to the transmission amount of the radiation passing through each part of the subject and sets the image area for determining the image processing condition. In the case of including the area setting means and the image processing condition setting means for setting the image processing condition based on the statistical property of the image data in the image area set by the area setting means, It is preferable that the state detecting means detects the distribution of the image data within the image area set by the area setting means among the image data subjected to the image processing by the image processing means.

As the data indicating the distribution state of the image data detected by the distribution state detecting means, the maximum value of the image data, the minimum value of the image data, the parameter indicating the degree of dispersion of the image data, and the predetermined range. Detecting at least one of a ratio of image data distributed in the image, a parameter indicating a degree of dispersion of the image data within the predetermined range, a maximum value of the unprocessed image data, and a minimum value of the unprocessed image data. It is better to let it.

Further, when a defect in the image data after the image processing is determined based on the quality determination signal, data indicating a distribution state of the detected image data and an initial value used for the quality determination. It is possible to provide image data reprocessing means for reprocessing the image data processed by the image processing means in the direction in which the quality determination means makes a good determination based on the comparison.

Here, the distribution state detecting means detects data indicating the distribution state of the image data reprocessed by the image data reprocessing means, and based on the data, the pass / fail judgment means is again defective. If it is determined that the image data to be input to the image processing unit is defective, it is preferable to provide a re-input condition notifying unit for notifying data indicating a proper input condition when re-inputting the image data.

Further, in place of the quality determining means, data indicating the distribution state of the image data detected by the distribution state detecting means is displayed as information for determining whether the processed image data is good or bad. It is also possible to provide a discrimination information display means. Further, the radiation image processing apparatus according to the present invention includes image processing means for performing image processing on image data of a radiation image formed corresponding to the amount of transmission of radiation passing through each part of a subject, and an image by the image processing means. Image data extracting means for extracting image data within a range corresponding to a preset predetermined output density range from the processed image data, and an image portion composed of the image data extracted by the image data extracting means. And a predetermined density image display means for displaying as information for determining whether the processed image data is good or bad.

Further, the radiation image processing apparatus according to the present invention includes an image processing means for performing image processing on the image data of the radiation image formed corresponding to the amount of radiation transmitted through each part of the subject, and this image processing. At least one of the image portion reflecting the photographing intention and the characteristic representative value of the image data reflecting the photographing intention is detected as information reflecting the preset photographing intention from the image data subjected to the image processing by the means. Determination information detecting means for detecting information to be recorded and the information detected by the determination information detecting means is displayed as information for determining whether the processed image data corresponds to the above-mentioned image capturing intention. And a discrimination display means.

[0021]

According to the above configuration, the data indicating the distribution state of the image data after the image processing is detected, and by comparing the data indicating the distribution state with the desired value of the data, the image data can be obtained as desired. It is determined whether or not the distribution state of 1 is obtained, and thus, the quality of the image data after the image processing is determined.

Here, when the image processing condition is set based on the statistical property of the image data in the specific image area, the inside of the specific image area is the main part, so that the image is not the entire image but the image. Based on the distribution state of the image data in the area, the quality of the image data after the image processing is determined, and if the desired distribution state is obtained in the area that determines the processing condition, it is determined as good. did.

As the data indicating the distribution state, the maximum value of the image data, the minimum value of the image data, the parameter indicating the degree of dispersion of the image data, the ratio of the image data distributed within a predetermined range, and the predetermined value. It suffices to detect at least one of the parameter indicating the degree of dispersion of the image data within the range, the maximum value of the unprocessed image data, and the minimum value of the unprocessed image data. Bias can be detected.

In the pass / fail judgment, since the data indicating the distribution state of the detected image data is compared with the desired value used for the pass / fail judgment, the actual distribution state is based on the comparison. Since it is possible to know the difference from the desired state and the direction of processing for approaching the desired state based on this, it is possible to make a good decision by reprocessing the image data that has been determined to be defective. It can be converted into such image data.

If a defect is determined even after the above-mentioned reprocessing, it is preferable to judge that the input image data to the image processing means is defective and to notify an appropriate input condition. Further, instead of automatically determining the quality of the image data based on the data indicating the detected distribution state, the data indicating the distribution state is displayed as information for determining the quality, and the information provided by this display is displayed. You may make it judge manually based on.

Further, instead of the data showing the distribution state, only the image portion consisting of the image data within the range corresponding to the predetermined output density range is displayed, and only the image data within the predetermined output density range is displayed. It may be possible to manually determine whether or not the image information is obtained.
Furthermore, at least one of the image portion reflecting the photographing intention and the characteristic representative value of the image data reflecting the photographing intention is detected as information reflecting the preset photographing intention from the image data subjected to the image processing. By detecting the information to be displayed and displaying it as information for determining whether or not the processed image data corresponds to the shooting intention, is it possible to obtain the image data as the shooting intention? Whether or not it can be easily determined.

[0027]

EXAMPLES Examples of the present invention will be described below. In the present embodiment, an apparatus for medical diagnosis using X-rays as radiation will be taken as an example. In FIG. 1 showing a radiographic image capturing / processing apparatus according to an embodiment, X-rays from an X-ray irradiating device 1 including an X-ray tube and the like pass through a subject 2 (human body in this embodiment) and a radiation conversion panel 3 Is irradiated. The radiation image conversion panel 3 has a stimulable phosphor layer, and when this phosphor is irradiated with X-rays that have passed through the subject 2, a part of the radiation energy is accumulated, and radiation image information is obtained. Is stored and recorded as a latent image.

The radiation image conversion panel 3 is irradiated with excitation light such as a laser beam from the excitation light source 4, and the irradiation of the excitation light causes the radiation image conversion panel 3 to emit light in accordance with the radiation energy accumulated and recorded. Exhaust emission occurs. This stimulated emission is input to the photoelectric converter 6 via the filter 5,
The photoelectric converter 6 photoelectrically converts the stimulated emission into a voltage signal,
This voltage signal is output to the image reading device 7 as a radiation image signal.

Here, the radiation image conversion panel 3 is
Imaging, image interpretation and erasing can be used repeatedly, and the radiation exposure area that can be recorded is extremely wide, so that differences in imaging conditions can be corrected and restored to some extent by image processing. The image reading device 7 converts the input voltage signal (radiation image signal) into digital image data and outputs the digital image data to the image processing device 8 (image processing means).

The image processing device 8 performs image processing of gradation conversion on the image data read from the radiation image conversion panel 3 and digitized, and outputs the image data.
As shown in FIG. 1, the anatomical region determination unit 9 (region setting unit) and the gradation processing condition determination unit 10 (image processing condition setting unit)
And a gradation processing unit 11 (image processing means).

For example, when the radiographic image is a chest image, there are completely unnecessary portions for the image data, such as the blank areas shown by a in FIG. 2, and the statistical analysis of the image data including these portions is performed. When the gradation processing condition is set from the nature, the gradation processing condition is affected by the blank portion, and it becomes impossible to easily reproduce the chest of interest. On the other hand, if the gradation processing condition is set based on the statistical property of only the image data included in the lung field part of the chest (the part surrounded by the broken line in FIG. 2), it will not be affected by the blank part, It is possible to perform optimum gradation processing with excellent interpretation of the lung field portion, which is the region of interest.

Therefore, in the case of a chest image, the anatomical region determination unit 9 detects a lung field region in the image based on the profile information of the image data, and the gradation processing condition determination unit 10 , A cumulative histogram (information indicating statistical properties) of the image data in the detected lung field region is created, and, for example, the portions corresponding to 5% and 95% of the cumulative histogram are the minimum output signal value and the maximum output. The gradation processing condition is determined so that the signal value is obtained.

Then, the gradation processing unit 11 performs gradation processing according to the gradation processing conditions determined from the statistical properties in the lung field region. The processing contents of the image processing device 8 are as follows.
This is merely an example, and the object portion to be targeted, the area detection method, and the gradation processing condition determination method are not limited, and the gradation processing condition may be determined from the image data of the entire area. .

Here, the image data subjected to the image processing by the gradation processing unit 11 is output to the image determination device 12, and the quality of the image data subjected to the image processing (whether the image data has a density effective for diagnosis is Whether or not) is determined by the image determination device 12. The histogram creation unit 13 constituting the image determination device 12 inputs the image data subjected to the gradation processing by the gradation processing unit 11 and creates a histogram for analyzing the distribution state of the image data.

Next, the histogram analysis unit 14 analyzes the created histogram to obtain data indicating the distribution state of image data. As the data indicating the distribution state, as described later, the maximum value of the image data, the minimum value of the image data, the parameter indicating the degree of dispersion of the image data, the ratio of the image data distributed within a predetermined range,
At least one of the parameter indicating the degree of dispersion of the image data within the predetermined range, the maximum value of the unprocessed image data, and the minimum value of the unprocessed image data is obtained from the histogram.

The histogram creating section 13 and the histogram analyzing section 14 constitute the distribution state detecting means in this embodiment. Then, the data indicating the distribution state is output to the pass / fail determination unit 15 (pass / fail determination unit), compared with a preset desired value here, and output from the gradation processing unit 11 based on the result. The quality of the gradation-processed image data is determined, and a quality determination signal is output. Then, the result of the quality determination (quality determination signal) is
It is output to the display device 16 or a warning lamp (not shown) to notify the photographer, and the photographer can switch the gradation processing conditions, or re-shoot when there is a defect that cannot be compensated by the gradation processing. To do so.

The quality determination unit 15 determines that the image data is good when all of the following six conditions are satisfied, and determines that the image data is defective if any of the conditions is not satisfied. "Good condition" 1) The output density of 1.0% to 2.
Must be within the range equivalent to 0 (concentration range effective for diagnosis; can be set for each device).

2) When the mode in the histogram of the data within the range corresponding to the output density of 1.0 to 2.0 (the density range effective for diagnosis; it can be set for each device) is 1, all the data are displayed on the histogram. The area ratio of the histogram waveform in the area obtained with the frequency data set to 1 is 0.5 or more. That is, the image data should be widely distributed without deviation within the output density range of 1.0 to 2.0.

3) The minimum value of the image data is the output density 0.5.
The following (concentration invalid for diagnosis; can be set for each device). 4) The maximum value of image data must be output density 2.5 or higher (density that is invalid for diagnosis; can be set for each device). 5) The minimum value of the unprocessed image data is greater than or equal to the reference signal value (signal value invalid for diagnosis; can be set for each device).

6) The maximum value of the unprocessed image data is less than or equal to the reference signal value (signal value invalid for diagnosis; can be set for each device). Incidentally, the condition (2) is, as shown in FIG. 10 or FIG. 11, on the histogram (FIG. 10 (a), FIG. 11 (a)) obtained by sampling only the image data within the output density 1.0 to 2.0. And the highest frequency is assumed to be 1 (Fig. 10 (b), Fig. 11
(B)), the area of a region (a rectangular region indicated by a dotted line in FIGS. 10 and 11) obtained when the frequency of image data is all 1 within the output densities of 1.0 to 2.0, and the area included in the region. The ratio to the area of the actual histogram waveform is obtained.

As shown in FIG. 10, the output density is 1.0 to 2.0.
If the image data is widely distributed within the area, the area ratio becomes large, and conversely, as shown in FIG.
When the image data is unevenly distributed within 2.0, the area ratio becomes small, and the area ratio is a parameter indicating the degree of dispersion of the image data. However, instead of calculating the area ratio as described above, the variance value may be calculated.

That is, the data before the image processing is within a certain range that can be corrected by the image processing, and the image data after the image processing is widely distributed, but the distribution is concentrated in the density range effective for diagnosis. In addition, a good judgment is made when the concentration is widely distributed within the concentration range. For example, even if the histograms (reading histograms) of the two image data read from the panel 3 before the image processing show different tendencies as shown in FIGS. 3 (a) and 4 (a), respectively, As shown in FIGS. 3B and 4B, the histogram of the image data after the tone processing is finally obtained when it is widely distributed over the entire range centering on the density range effective for diagnosis. The image data (image data after gradation processing) are both determined to be good according to the above determination.

Here, as shown in FIGS. 4 (a) and 4 (b), even if the reading histogram is biased toward the side with a small transmitted dose due to insufficient dose at the time of photographing, and the photographing process is unsuccessful, image processing is performed. Corrected and restored by this, and good image data (a large amount of image data is included in the density range effective for diagnosis, and is still widely distributed within the range)
In some cases. In the present embodiment, the quality is judged not from the read histogram but from the histogram of the image data after the gradation processing as described above, and therefore it is avoided that a defective judgment is made based on the read histogram and unnecessary re-imaging is performed. it can.

On the other hand, the histogram of the image data after gradation processing is, for example, as shown in FIG.
As shown in (b), when the distribution is biased toward the high density side, the above six conditions cannot be satisfied at the same time, and it is determined as defective data, so that the desired gradation processing is performed. It is possible to prevent the radiation image data in the absence state from being stored as it is.

Further, when the maximum or minimum value of the image data before the image processing is at a level outside the reference range that is difficult to compensate by the image processing, the image data after the image processing need not be verified and the image data need not be verified. It is possible to determine that the processed image data is defective. By the way, as described above, when the region of interest is detected and the processing condition is determined based only on the image data in the region of interest, the purpose is to finish the region of interest to a desired density, Is whether or not is processed according to the above purpose.

Therefore, in this case, only the image data in the region of interest set for determining the gradation processing condition is extracted from the image data after the gradation processing, and the histogram of the extracted image data is converted into a histogram. The creating unit 13 creates the file. Then, the histogram analysis unit 14 analyzes the histogram in the region of interest, and the quality determination unit 15 determines whether the quality is good or bad based on the analysis result.

In this case, the pass / fail judgment unit 15 judges the gradation-processed image data as good only when, for example, all of the following seven conditions are satisfied, and the histogram analysis unit 14 uses it for the following judgment. Seven types of data indicating the distribution state of the histogram are obtained. "Good judgment condition" 1) 80% or more of the data in the area (region of interest) set for setting the gradation processing condition is output density 1.0 to 2.0 (density range effective for diagnosis; set for each device) Yes) within the range corresponding to.

2) Of the image data in the region (region of interest) set for setting the gradation processing conditions, the output density is 1.0
~ 2.0 (concentration range effective for diagnosis; can be set for each device) When the mode in the histogram of the data within the range is 1, the area where all frequency data is obtained as 1 on the histogram The area ratio of the histogram waveform inside is 0.7 or more. That is, the output density is 1.0 to 2.
The image data in the ROI included in the range of 0 should be widely distributed without any bias.

3) The maximum value of the image data in the region (region of interest) set for setting the gradation processing condition is the output density.
Be within a range corresponding to 1.5 to 2.5 (can be set for each device). 4) The minimum value of the image data in the area (region of interest) set for setting the gradation processing condition is the output density of 0.5 to 1.5.
Be within the range corresponding to (can be set for each device).

5) The variance value of the image data in the region (region of interest) set for setting the gradation processing condition is within a certain range. 6) The minimum value of the unprocessed image data in the region (region of interest) set for setting the gradation processing condition is greater than or equal to the reference signal value (signal value invalid for diagnosis; settable for each device). thing.

7) The maximum value of the unprocessed image data in the region (region of interest) set for setting the gradation processing condition is the reference signal value (signal value invalid for diagnosis; can be set for each device). Being below. For example, in the case where the subject is the foot of the human body and the region of interest is the tip of the foot as shown in FIG. 6A, the quality is judged from the histogram of the entire image as described above, If the histogram after the image processing is biased toward the high density side as shown in FIG. 6C with respect to the histogram before the image processing (FIG. 6B), it is determined to be defective. I will end up.

However, as described above, the histogram created only from the image data in the toe region, which is the region of interest, may be concentrated in a relatively low portion (density range effective for diagnosis) of the entire image. Image data suitable for diagnosis of at least the region of interest,
As described above, by judging from the image data of only the area set for setting the gradation processing condition, it is possible to judge whether the area of interest is image-processed so that it is easy to see, instead of the whole tendency. it can.

Here, for example, the display device 16 (quality determination information display means) is caused to display a radiation image based on the image data after the image processing, and is set in the image to determine the gradation processing condition. The area is displayed as a frame (Fig. 6
(See (a)), which of the four conditions has been cleared is displayed (the actual histogram data and the judgment level may be displayed at the same time), and the result is given on the display device 16. The photographer may be allowed to determine the quality based on the actual image information and the determination data. Alternatively, the photographer may be allowed to select whether or not to adopt the automatic determination result as it is. Further, the provision of the determination information to the photographer may be applied to the above-described embodiment in which the data indicating the distribution state is detected from the histogram of the entire image.

In addition, a density range that is easy to read in advance (for example, 1.
0 to 1.5) is set and only the portion corresponding to the density range is extracted from the image data after image processing (entire image or region of interest) and displayed on the display device 16 (when such a function is It corresponds to a predetermined density image display means.), And the photographer may be allowed to judge the quality based on this display image. Here, the extraction of the image data can be performed by the quality determination unit 15, and the quality determination unit 15 also serves as image data extraction means.

As described above, if the actual image information, the judgment data, or the portion of the predetermined density range is extracted and displayed on the display device, and the photographer judges whether the image quality is good or not based on these information, In the case where the histogram of the processed image data is automatically judged by the above-mentioned judgment criteria, even when the judgment is good, the image data is not processed even when the photographer intends to do so. However, this can be determined to be defective.

For example, as shown in FIGS. 7 (a) and 7 (b), although high-pressure photography is performed to try to observe a specific portion widely, a process for widely distributing image data by gradation processing is performed. As a result, when the effect of high-voltage photography disappears, the photographer can detect the inappropriateness of the signal value of the main part of the image and the inappropriateness of the specified density part by providing the information as described above. The photographer can determine that the distribution is defective even if the distribution is determined to be good by the automatic determination.

In this case, it is possible to obtain the intended radiation image information by high-voltage imaging by resetting the gradation processing conditions to those suitable for the high-voltage imaging (FIG. 8 (a), ( See b)). In addition, as shown in FIGS. 9A and 9B, when the imaging is failed due to an excessive dose but the processing is performed by the gradation processing so that the histogram is distributed over the entire range, the imaging is performed. However, the gradation process is successful, but a good judgment is made by the success of the gradation process. In this case also, the photographer can make a correct determination by providing the determination information.

As described above, depending on the photographer's intention of photographing, the fact that the histogram of the processed image data is distributed over a wide range does not necessarily mean that the desired image data is obtained. Therefore, the photographer's intention of photographing (high-voltage photographing, low-voltage photographing, wanting to observe a specific part, etc.) can be set in advance in the quality determination system,
Detects data (entire contrast, output density value of a specific part, etc.) or image part that is convenient for determining whether or not the image is processed according to the preset shooting intention, and provides this to the photographer for shooting. The person may be allowed to judge the quality.

Specifically, the intention of photographing such as high-voltage photographing, low-pressure photographing, and observation of a specific region is set in advance, and data reflecting the intention (total contrast,
An image portion reflecting the intention of the output density value of a specific part) or its intention is detected by the pass / fail judgment unit 15 corresponding to the discrimination information detection unit, and the detection result is displayed on the display device 16 (the function is to discriminate the photographing intention). It corresponds to the display means), and allows the photographer to make a pass / fail judgment based on the displayed information.

By doing so, although it is intended to project many tissues on one image at the time of high-voltage imaging, for example, as shown in FIGS. 7A and 7B, the image data is processed by gradation processing. Although the process of widely distributing is performed and the gradation process is successful, if the photographing intention is not achieved, it is confirmed that the process corresponding to the high-voltage photographing intended based on the information is not performed. Can be determined. Therefore, the radiation image intended by the photographer can be obtained by resetting the processing conditions suitable for high-voltage imaging and performing the processing again (see FIGS. 8A and 8B).

Here, when the high-voltage shooting or the low-voltage shooting is set in advance, the characteristics are changed so as to suppress the tendency to change the contrast as compared with the gradation processing corresponding to the normal shooting, and the high-voltage shooting or the low-voltage shooting is performed in advance. The gradation processing may be performed with a characteristic that conforms to, and the pass / fail determination may be performed by changing the reference level of the automatic pass / fail determination according to the gradation processing. By the way, when a defect is judged as described above,
How to change the characteristics of the gradation processing based on the comparison between the histogram of the image data after the image processing, which is the basis of the defect judgment, and the characteristics that are judged to be good, so that a good judgment can be made. Can be determined. Therefore, the reprocessing condition determination unit
Responsive to the determination information of the quality determination unit 15 in 17 to determine the following reprocessing conditions according to the item determined to be defective, the image data in the reprocessing unit 18 based on the determined reprocessing conditions. It is possible to obtain image data that is finally judged to be good by re-processing.

The reprocessing condition determining unit 17 and the reprocessing unit
The image data reprocessing means is constituted by 18. "Reprocessing condition" 1) Output density of 1.0% to 2.
When it is not within the range equivalent to 0 (effective concentration range for diagnosis; can be set for each device).

[Reprocessing] → When the distribution of the processed image data is concentrated on the high signal side, the processing is performed so as to be widely distributed to the low signal side, and conversely, the processed image is processed. When the data distribution is concentrated on the low signal side, processing is performed so that the data is widely distributed even on the high signal side. 2) When the mode value in the histogram of the data within the range corresponding to the output density 1.0 to 2.0 (the density range effective for diagnosis; can be set for each device) is 1, all frequency data is displayed on the histogram. When the area ratio of the histogram waveform in the area obtained as 1 is not 0.5 or more.

[Reprocessing] → Processing for wide distribution is performed. 3) When the minimum value of the image data of the entire image is not less than the output density of 0.5 (density that is invalid for diagnosis; can be set for each device). [Reprocessing] → Processing for shifting to the lower density side is performed. 4) When the maximum value of the image data is not the output density of 2.5 or higher (density that is invalid for diagnosis; can be set for each device).

[Reprocessing] → Processing for shifting to the high density side is performed. 5) When the minimum value of the unprocessed image data is not greater than or equal to the reference signal value (signal value invalid for diagnosis; can be set for each device). [Reprocessing] → Processing for shifting to the high density side is performed. 6) The maximum value of the unprocessed image data is not less than or equal to the reference signal value (signal value invalid for diagnosis; can be set for each device).

[Reprocessing] → A process for shifting to the low density side is performed. 7) 80% or more of the data in the area (region of interest) set for setting the gradation processing conditions corresponds to output density 1.0 to 2.0 (density range effective for diagnosis; can be set for each device) If not within range. [Reprocessing] → The image density in the region of interest is output as 1.
Perform processing to concentrate on 0 to 2.0.

8) Of the image data in the region (region of interest) set for setting the gradation processing condition, the output density is 1.0
~ 2.0 (concentration range effective for diagnosis; can be set for each device) When the mode in the histogram of the data within the range is 1, the area where all frequency data is obtained as 1 on the histogram When the area ratio of the histogram waveform in is not more than 0.7.

[Reprocessing] → Processing is performed so that the region of interest is narrowed. 9) The maximum value of the image data in the area (region of interest) set to set the gradation processing condition is the output density of 1.5 to 2.5.
When it is not within the range corresponding to (can be set for each device). [Reprocessing] → Processing for shifting to the high density side is performed.

10) The minimum value of the image data in the region (region of interest) set for setting the gradation processing condition is the output density.
When it is not within the range equivalent to 0.5 to 1.5 (can be set for each device). [Reprocessing] → Processing for shifting to the lower density side is performed. 11) When the variance value of the image data in the area (region of interest) set for setting the gradation processing conditions is not within a certain range.

[Reprocessing] → When the dispersion is small (when the contrast is high), the processing for lowering the contrast is performed. On the contrary, when the dispersion is high (when the contrast is low), the contrast is high. Performs such processing. 12) When the minimum value of the unprocessed image data in the area (region of interest) set for setting the gradation processing conditions is not greater than or equal to the reference signal value (signal value invalid for diagnosis; can be set for each device) .

[Reprocessing] → Processing for shifting to the high density side is performed. 13) When the maximum value of the unprocessed image data in the area (region of interest) set for setting the gradation processing conditions is not less than the reference signal value (signal value invalid for diagnosis; can be set for each device) . [Reprocessing] → Processing for shifting to the lower density side is performed.

As described above, even when the defective image data is reprocessed, if the defective image is determined again, it is determined that there is a defective photographing condition that cannot be compensated by the image processing. Considering and displaying from the distribution of the image data before processing, how much the imaging conditions (dose / tube voltage) should be adjusted as data on the display device 16,
The photographer may be provided with the adjustment data (this function corresponds to the re-input condition notifying means), or the photographing condition may be automatically set to re-photograph.

[0073]

As described above, according to the present invention, it is possible to detect data indicating the distribution state of image data after image processing, and determine whether the processed image data is good or bad based on the detection result. This makes it possible to avoid unnecessary re-imaging when it is possible to obtain good radiation image data by compensating for the imperfections in the image processing even if there is a poor imaging condition, and it is possible to perform good imaging. Also, when the desired radiation image cannot be obtained due to insufficient processing conditions, it is possible to perform processing such as reprocessing by changing the processing conditions.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an entire system showing an embodiment of the present invention.

FIG. 2 is a diagram showing setting of gradation processing conditions by setting a region of interest.

FIG. 3 is a diagram showing a distribution state of image data when both imaging and processing are performed favorably.

FIG. 4 is a diagram showing a distribution state of image data in a case where a defective image is corrected by image processing.

FIG. 5 is a diagram showing a distribution state of image data when image processing fails.

FIG. 6 is a diagram for explaining the effect of quality determination by specifying a region of interest.

FIG. 7 is a diagram showing a distribution state of image data when a process that does not reflect high-voltage imaging is performed.

FIG. 8 is a diagram showing a distribution state of image data when reprocessing reflecting high-voltage imaging is performed.

FIG. 9 is a diagram showing an example of a case in which it is determined as apparently good by image processing although shooting has failed.

FIG. 10 is a diagram for explaining an area ratio on a histogram as a parameter indicating a degree of dispersion of image data.

FIG. 11 is a diagram for explaining an area ratio on a histogram as a parameter indicating a degree of dispersion of image data.

[Explanation of symbols]

 1 X-ray irradiation device 3 Radiation conversion panel 7 Image reading device 8 Image processing device 9 Anatomical region determination unit 10 Gradation processing condition determination unit 11 Gradation processing unit 12 Image determination device 13 Histogram creation unit 14 Histogram analysis unit 15 Good or bad Judgment unit 16 Display device 17 Reprocessing condition determination unit 18 Reprocessing unit

Claims (8)

[Claims] 1. Image processing means for performing image processing on image data of a radiation image formed corresponding to the amount of transmission of radiation passing through each part of an object, and image data subjected to image processing by the image processing means. Distribution state detecting means for detecting data indicating the distribution state of the image data, the image processing means based on the comparison between the data indicating the distribution state of the image data detected by the distribution state detecting means and the desired value of the data. A radiographic image processing apparatus comprising: a quality determining unit that determines whether the image data after processing by the process is good or bad and outputs a good or bad determination signal. 2. The image processing means sets image areas for determining image processing conditions by analyzing image data of a radiation image formed corresponding to a transmission amount of radiation passing through each part of a subject. The distribution state detecting means, which includes: area setting means; and image processing condition setting means for setting image processing conditions based on the statistical properties of image data in the image area set by the area setting means. 2. The radiation according to claim 1, wherein a distribution of image data within the image area set by the area setting means is detected from the image data subjected to the image processing by the image processing means. Image processing device. 3. The data indicating the distribution state of the image data detected by the distribution state detecting means includes a maximum value of the image data, a minimum value of the image data, a parameter indicating a degree of dispersion of the image data, and a predetermined range. A ratio of the image data distributed within, a parameter indicating the degree of dispersion of the image data within the predetermined range, the maximum value of the unprocessed image data,
The radiation image processing apparatus according to claim 1, wherein the radiation image processing apparatus is at least one of the minimum value of the unprocessed image data. 4. A data indicating a distribution state of the detected image data when a defect of the image data after the image processing is determined based on the quality determination signal, and an initial value used for the quality determination. The image data reprocessing means for reprocessing the image data processed by the image processing means is provided in the direction in which the quality determination means determines whether the image data is good or bad. Or the radiographic image processing device according to any one of 3 above. 5. The distribution state detecting means detects data indicating a distribution state of the image data reprocessed by the image data reprocessing means, and based on the data, the pass / fail judgment means determines again as defective. When the determination is made, it is determined that the image data input to the image processing means is defective, and re-input condition notifying means for notifying data indicating a proper input condition when re-inputting the image data is provided. 4. The radiation image processing device according to 4. 6. Instead of the quality determining means, data indicating the distribution state of the image data detected by the distribution state detecting means is displayed as information for determining the quality of the processed image data. The radiation image processing apparatus according to claim 1, further comprising a quality determination information display unit. 7. Image processing means for performing image processing on image data of a radiation image formed corresponding to the amount of transmission of radiation passing through each part of a subject, and image data subjected to image processing by the image processing means. From
An image data extraction unit that extracts image data within a range corresponding to a preset predetermined output density range, and only an image portion composed of the image data extracted by the image data extraction unit, A radiographic image processing apparatus comprising: a predetermined density image display unit that displays information for determining whether the image is good or bad. 8. Image processing means for performing image processing on image data of a radiation image formed corresponding to the amount of transmission of radiation passing through each part of a subject, and image data subjected to image processing by the image processing means. From
Discrimination information detecting means for detecting at least one of an image portion reflecting the photographing intention and a characteristic representative value of image data reflecting the photographing intention as the information reflecting the preset photographing intention, and the discrimination. The information detected by the information detecting means is displayed as information for determining whether or not the processed image data corresponds to the above-mentioned shooting intention, and a shooting intention determination display means is included. A characteristic radiation image processing apparatus.