JP3312281B2 - Radiation image processing device - Google Patents

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 whether a result of photographing and image processing is good when performing image processing on image data of a radiation image. .

[0002]

2. Description of the Related Art Radiation images such as X-ray images are widely used for diagnosing diseases and the like. In order to obtain such X-ray images, X-rays transmitted through a subject are applied to a phosphor layer (fluorescent screen). A so-called radiograph, which is obtained by irradiating a visible light to thereby generate a visible light and irradiating the visible light to a film using a silver salt in the same manner as a normal photograph and developing the film, has been conventionally used.

However, in recent years, a method has been devised for directly taking out an image from a phosphor layer without using a film coated with a silver salt. This includes:
The radiation transmitted through the subject is absorbed by the phosphor, and then the phosphor is excited by, for example, light or heat energy, thereby radiating the radiation energy accumulated by the phosphor as a result of the absorption. There is a method of obtaining an image signal by photoelectrically converting

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 stimulating excitation light. ing. This method uses a radiation image conversion panel having a stimulable phosphor layer formed on a support,
Radiation transmitted through the subject is applied to the stimulable phosphor layer of this conversion panel to accumulate radiation energy corresponding to the radiation transmittance of each part of the subject to form a latent image. By scanning with the excitation light, the radiation energy accumulated is emitted, converted into light, and this optical signal is photoelectrically converted to obtain a radiation image signal.

The radiation image signal thus obtained is output as it is or subjected to image processing to a silver halide film, a CRT or the like to be visualized, or is filed in an electronic filing device. In the image processing, the purpose of finishing the density of a region of interest (a region including an image portion necessary for diagnosis for medical use) in a reproduced image to be constant, and to output a shadow (region of interest) of a human body structure or a lesion more easily. For this purpose, image processing such as gradation processing and spatial frequency processing is performed.

For example, in a radiation image processing apparatus disclosed in Japanese Patent Application Laid-Open No. 3-218578, a region of interest is determined by analyzing an image signal, and a gradation processing condition is automatically determined based on the image signal in the region of interest. It is disclosed that the gradation processing is performed by determining the output image, and thereby, an output image with stable density and gradation is automatically obtained, and the diagnostic performance can be improved.

[0007]

By the way, in the radiography described above, the radiographer (radiologist) adjusts the irradiation dose, tube voltage, and the like according to the patient's body shape and the site to be observed based on the know-how acquired from experience. However, the output image is faithfully reproduced as it is in accordance with the adjustment result of the photographer.
However, there is a possibility that the imaging may fail due to the specificity of the patient's body type or an imaging error, and the quality of the imaging is determined by visually observing the radiograph visualized by the development processing,
According to the result of this determination, measures such as re-photographing were taken.

In this respect, in the case of a system for obtaining a radiation image signal using the radiation image conversion panel, the quality of the photographing (improper photographing condition and / or reading condition) can be determined on the spot because development processing is unnecessary. Since it can be immediately identified, and image processing is performed after shooting and reading as an image signal,
It is also possible to obtain a desired image by supplementing the image pickup conditions and reading conditions with some degree of image processing.

Further, in the system for obtaining the radiation image signal as described above, since the radiation image information is handled as an image signal, it is possible to automate the quality judgment. Therefore, an apparatus for automatically determining a radiographing defect from a radiation image signal before image processing (see Japanese Patent Application Laid-Open No. 3-19090) and an apparatus for determining the reliability of image processing conditions determined from an image signal (Japanese Patent Application Laid-Open No. No. 2-14376) has been proposed, which makes it possible to independently determine the quality of photographing and image processing, and to perform re-photographing and resetting of processing conditions.

However, even if the photographing (photographing conditions and / or reading conditions) and the image processing are each executed independently 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 density by image processing, the contrast will be low,
If image processing is performed with 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 quality of each of the photographing (photographing conditions and / or reading conditions) and image processing is independently determined, the actually obtained image-processed image is as intended by the photographer. However, if the processing is performed as it is based on the determination that each of the imaging and image processing has succeeded independently, there is a possibility that the diagnostic performance will be reduced when a radiation image is used for an actual diagnosis later.

Further, even when it is determined from the radiation image signal before the image processing that the radiography is defective, there is a case where the defect can be compensated for by the image processing. If re-imaging is performed based on the determination, re-imaging and re-processing will be performed uselessly. The present invention has been made in view of the above problems, radiation image information obtained as image data,
In a radiographic image processing apparatus that performs image processing on this, after performing a series of flows of imaging, reading, and image processing, an apparatus that can determine the quality of the obtained image information is provided. It is an object of the present invention to surely obtain radiation image information excellent in diagnostic performance.

It is another object of the present invention to obtain radiation image data for which a good determination is made by reprocessing when a defect is determined by the quality determination.

[0014]

SUMMARY OF THE INVENTION Therefore, a radiation image processing apparatus according to the present invention performs image processing on image data of a radiation image formed corresponding to the amount of radiation transmitted through each part of a subject. And the distribution state of the density values of the image data subjected to image processing by this image processing means.
Distribution state detecting means for detecting data to be represented; and distribution state of density values of image data detected by the distribution state detecting means.
And a pass / fail determining unit that determines pass / fail of the image data processed by the image processing unit based on a comparison between the data representative of the state and an expected value of the data, and outputs a pass / fail determination signal. It consists of.

Here, the image processing means sets an image area for determining image processing conditions by analyzing image data of a radiation image formed corresponding to the amount of radiation transmitted through each part of the subject. When the image processing apparatus includes an area setting unit and an image processing condition setting unit that sets an image processing condition based on a statistical property of image data in the image area set by the area setting unit, a distribution state detecting means, at the set image area by the area setting means among the image data subjected to image processing by the image processing means, image
It is preferable to detect data representative of the distribution state of data density values .

Further, an image detected by the distribution state detecting means is provided.
As data representing the distribution state of the concentration value of the data ,
A maximum value of the density value of the image data , a minimum value of the density value of the image data , a parameter indicating a degree of dispersion of the density value of the image data, a ratio of image data distributed within a predetermined density range, and the predetermined density range. or a parameter indicating the degree of dispersion of the image data to be distributed within a maximum value of the density values of the unprocessed image data, when so as to detect at least one of the minimum value of the density values of the unprocessed image data .

Further, when a defect of the image data after image processing is determined based on the pass / fail determination signal, data representative of a distribution state of density values of the detected image data ;
An image data reprocessing means for reprocessing the image data processed by the image processing means can be provided in a direction in which the quality is judged by the quality judgment means based on a comparison with an expected value used for the quality judgment. .

[0018] Here, the distribution state detecting means, dark image data subjected to reprocess the image data reprocessing means
Data representative of the distribution of frequency values is detected, and if the pass / fail determination unit again determines a defect based on the data, it is determined that the image data input to the image processing unit is defective, and the image data is re-determined. It is preferable to provide a re-input condition notifying unit for notifying data indicating an appropriate input condition at the time of input.

Also, the distribution state of the density value of the image data detected by the distribution state detecting means instead of the pass / fail determination means.
May be provided as display means for displaying data representing the above as information for determining whether the processed image data is good or bad. In addition, a radiation image processing apparatus according to the present invention includes: an image processing unit that performs image processing on image data of a radiation image formed in accordance with an amount of radiation transmitted through each part of a subject; Image data extraction means for extracting, from the processed image data, image data within a range corresponding to a predetermined output density range, and an image portion comprising the image data extracted by the image data extraction means And a predetermined density image display means for displaying only the image data as information for judging pass / fail of the processed image data.

Further, the radiation image processing apparatus according to the present invention comprises: 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 the subject; from the image data subjected to image processing by means preliminarily set region to be observed
Preset for use in determining image parts and image processing results
Discrimination information detection means for detecting information for detecting at least one of the characteristic representative value of the density value of the processed image data, and the information detected by the discrimination information detection means, And a photographing intention determining and displaying means for displaying as information for determining whether or not they are compatible.

[0021]

According to the above arrangement, the image data after the image processing is
Data representative of the distribution state of the density value is detected, and by comparing the data indicating the distribution state with the expected value of the data, it is determined whether or not the image data has the expected distribution state. Thus, the quality of the image data after the image processing is determined.

Here, when the image processing conditions are set based on the statistical properties of the image data in the specific image area, since the inside of the specific image area is the main part, the image is not the entire image but the image. Density of image data in area
Data representative of the value distribution state is detected, and based on the data, the quality of the image data after the image processing is determined, and a desired distribution state is obtained within the area for determining the processing conditions. If so, it is determined to be good.

The data representative of the distribution state is as follows:
A maximum value of the density value of the image data , a minimum value of the density value of the image data , a parameter indicating a degree of dispersion of the density value of the image data, a ratio of image data distributed within a predetermined density range, and the predetermined density range. often a parameter indicating the degree of dispersion of the image data to be distributed within a maximum value of the density values of the unprocessed image data, if detected at least one of the minimum value of the density values of the unprocessed image data, The bias of the image data can be detected from these data.

In the pass / fail judgment, since data representative of the distribution state of the detected density value is compared with the desired value used in the pass / fail judgment, the actual distribution state is determined based on the comparison. And the intended state can be known, and further, the direction of processing for approaching the expected state can be known based on this, so that the image data determined to be defective is determined to be good by reprocessing. Image data.

When a defect is determined even after performing the above-described reprocessing, it is preferable that the input image data to the image processing means is determined to be defective and appropriate input conditions are notified. Moreover, the quality of image data based on the data representative of the detected distribution Instead of automatically discriminating the data representing the distribution, is displayed as the information for determining the quality, provided by the display The determination may be made manually based on the information.

Further, instead of data representing the distribution state, only the image portion consisting of 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. Whether or not the image information of the period has been obtained may be manually determined. Furthermore, from the image data subjected to image processing, observation
An image portion preset as an area to be processed and image processing
The density of the image data set in advance for use in
If the information for detecting at least one of the characteristic representative value of the degree value is detected, and this is displayed as information for determining whether or not the processed image data corresponds to the photographing intention, In addition, it can be easily determined whether or not image data as intended is obtained.

[0027]

Embodiments of the present invention will be described below. In this embodiment, an apparatus for medical diagnosis using X-rays as radiation will be described as an example. In FIG. 1 showing a radiation image capturing / processing apparatus according to one embodiment, X-rays from an X-ray irradiating apparatus 1 composed of an X-ray tube or the like pass through a subject 2 (in the present embodiment, a human body) and a radiation conversion panel 3. Is irradiated. The radiation image conversion panel 3 has a stimulable phosphor layer. When the phosphor is irradiated with X-rays transmitted through the subject 2, a part of the radiation energy is accumulated and the radiation image information is stored. Is stored as a latent image.

The radiation image conversion panel 3 is irradiated with excitation light such as laser light 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 stored and recorded in the radiation image conversion panel 3. Emitting light 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 comprises:
The radiographing, image reading, and erasing can be used repeatedly, and the radiation exposure area that can be recorded is extremely wide, so that the difference in radiographing conditions can be corrected and recovered 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 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 determining unit 9 (region setting unit) and the gradation processing condition determining 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 a blank region shown in FIG. 2A, and the statistical data of the image data including these portions is included. If the gradation processing condition is set due to the nature, the gradation processing condition is affected by the blank portion, and the chest, which is the interested portion, cannot be easily reproduced and cannot be reproduced. On the other hand, if the gradation processing condition is set based on the statistical properties of only the image data included in the lung field part of the chest (the part surrounded by the broken line in FIG. 2), the influence of the blank part is eliminated. It is possible to perform optimal gradation processing that is excellent in the readability of the lung field part, 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 from the image based on, for example, profile information of image data, and the gradation processing condition determination unit 10 Image in the detected lung field area
A cumulative histogram (information indicating statistical properties) of the density values of the image data is created, for example, 5% of the cumulative histogram
And 95% are determined such that the minimum output signal value and the maximum output signal value correspond to the gradation processing conditions.

Then, the gradation processing section 11 performs gradation processing according to gradation processing conditions determined from statistical properties in the lung field area. The processing contents of the image processing device 8 are as follows.
This is merely an example, and the present invention is not limited to a subject portion to be targeted, a method of detecting an area, and a method of determining a gradation processing condition. A configuration in which the gradation processing condition is determined from image data of the entire area may be used. .

Here, the image data subjected to the image processing by the gradation processing section 11 is output to an image judging device 12 to determine whether the image data subjected to the image processing is good or bad (finished to a density effective for diagnosis). Is determined by the image determination device 12. The histogram creating unit 13 constituting the image determination device 12 receives 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 density values of the image data. .

Next, the histogram analyzer 14 analyzes the created histogram to obtain data representative of the distribution state of the density values of the image data. As data indicating the distribution state, as described later, the image data conc
And the maximum value of the degrees value, a parameter indicating the minimum value of the density values of the image data, the degree of dispersion of the density value of the image data, predetermined
The ratio of image data distributed within the density range and the predetermined density
A parameter indicating the degree of dispersion of the image data to be distributed in the degree range, the maximum value of the density values of the unprocessed image data, at least one of the minimum value of the density values of the unprocessed image data
One is determined from the histogram.

Note that the histogram creating section 13 and the histogram analyzing section 14 constitute a 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 means), where it is compared with a predetermined value set in advance, 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 pass / fail judgment (pass / fail judgment signal) is
The information is output to the display device 16 or a warning lamp (not shown) to notify the photographer, and the photographer is allowed to switch the gradation processing condition, or to re-photograph when there is a defect that cannot be compensated by the gradation processing. To do.

The pass / fail judgment unit 15 judges that the image data is good if all of the following six conditions are satisfied, and judges that the image data is bad if any of the conditions is not satisfied. "Good judgment condition" 1) Data of 30% or more of the entire image is output density 1.0 to 2.
0 (concentration range effective for diagnosis; can be set for each device).

2) When the mode value in the histogram of the data within the range corresponding to the output density of 1.0 to 2.0 (a density range effective for diagnosis; settable for each device) is set to 1, The area ratio of the histogram waveform in the region where the frequency data is set to 1 is 0.5 or more. That is, the image data must be widely distributed without bias within the output density range of 1.0 to 2.0.

3) The minimum value of the image data is 0.5
The following (invalid concentration for diagnosis; can be set for each device). 4) The maximum value of the image data is not less than the output density of 2.5 (density invalid for diagnosis; can be set for each device). 5) The minimum value of the pre-processing image data is equal to or more than a reference signal value (a signal value invalid for diagnosis; settable for each device).

6) The maximum value of the image data before processing is equal to or less than a reference signal value (a signal value invalid for diagnosis; settable for each device). Note that the condition (2) is, as shown in FIG. 10 or FIG. 11, a histogram (FIGS. 10 (a) and 11 (a)) obtained by sampling only image data having an output density of 1.0 to 2.0. And the highest frequency is assumed to be 1 (FIG. 10 (b), FIG. 11).
(B)) The area of the area (square area shown by the dotted line in FIGS. 10 and 11) obtained when the frequency of the image data is all 1 within the output density of 1.0 to 2.0, and is included in the area This is to determine the ratio with the area of the actual histogram waveform.

As shown in FIG. 10, the output density is 1.0 to 2.0.
When the image data is widely distributed in the area, the area ratio becomes large, and conversely, as shown in FIG.
If 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, a 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 determination is made when the image is widely distributed within the above-mentioned density range. For example, even if the histograms (reading histograms) of two pieces of image data read from the panel 3 before image processing show different tendencies as shown in FIG. 3A and FIG. As shown in FIGS. 3B and 4B, when the histogram of the image data after the tone processing is widely distributed over the entire range centering on the density range effective for diagnosis, it is finally obtained. 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 where the transmitted dose is small due to the lack of the dose at the time of imaging, and the imaging fails, the image processing is performed. And corrects and recovers the image data to obtain good image data (image data that includes a large amount of image data in a density range effective for diagnosis and is widely distributed in the range).
In some cases, it can be done. In the present embodiment, the pass / fail is determined not from the read histogram but from the histogram of the image data after the gradation processing as described above. Therefore, it is possible to avoid a failure determination based on the read histogram and wasteful re-shooting. it can.

On the other hand, even if the photographing is performed under almost optimal conditions, the histogram of the image data after the gradation processing is, for example, shown in FIG.
As shown in (b), if 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 radiation image data in a state where no radiation image data is stored as it is.

When the maximum or minimum value of the image data before the image processing is outside the reference range which is difficult to compensate even by the image processing, the image data after the image processing 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. The problem is whether or not is processed as described above.

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 creation unit 13 creates the information. Then, the histogram in the region of interest is analyzed by the histogram analysis unit 14, and based on the analysis result, the pass / fail determination is performed by the pass / fail determination unit 15.

In this case, the pass / fail judgment unit 15 judges that the gradation-processed image data is good only when all of the following seven conditions are satisfied, for example, and the histogram analysis unit 14 uses the image data 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 region (region of interest) set for setting the gradation processing condition is output density 1.0 to 2.0 (a density range effective for diagnosis; set for each device) Yes).

2) Among image data in a region (region of interest) set for setting a gradation processing condition, an output density of 1.0
To 2.0 (concentration range effective for diagnosis; settable for each device) When the mode value in the histogram of data within a range corresponding to 1 is set to 1, an area where all frequency data is obtained as 1 on the histogram The area ratio of the histogram waveform in the area must be 0.7 or more. That is, the output density is 1.0 to 2.
The image data in the region of interest included in the range of 0 is widely distributed without 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
Must be within the range of 1.5 to 2.5 (can be set for each device). 4) The minimum value of the image data in the region (region of interest) set for setting the gradation processing condition is such that the output density is 0.5 to 1.5.
(Can be set for each device).

5) The variance 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 pre-processing image data in the region (region of interest) set for setting the gradation processing condition is equal to or greater than a reference signal value (a 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 equal to the reference signal value (signal value invalid for diagnosis; settable for each device) Must be: For example, if the subject is the foot of a human body and the region of interest is the tip of the foot as shown in FIG. 6A, as described above, the quality of the image is determined based on the histogram of the entire image. 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.

However, as described above, the histogram created from only the image data in the toe region, which is the region of interest, is concentrated in a relatively low portion (a density range effective for diagnosis) in the entire image. This means that at least image data suitable for diagnosing the region of interest has been obtained,
As described above, by making a determination based on the image data of only the region set for setting the gradation processing condition, it is possible to determine whether the region of interest is good or not based on whether the region of interest has been image-processed so that it is easy to see, rather than the overall tendency. it can.

Here, for example, the display device 16 (pass / fail determination information display means) displays a radiographic image based on the image data after the image processing, and sets the radiographic image in the image to determine the gradation processing condition. The framed area is displayed as a frame (Fig. 6
(Refer to (a)), and which of the four conditions is cleared is displayed (the actual histogram data and the judgment level may be displayed simultaneously). The photographer may be allowed to make a pass / fail decision based on the actual image information and the decision data. Alternatively, the photographer may be allowed to select whether to adopt the automatic determination result as it is. 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.

Further, a density range (for example, 1.
0 to 1.5) are set, and only the portion corresponding to the density range is extracted from the image data after image processing (the entire image or the region of interest) and displayed on the display device 16 (this function is not available). This may be equivalent to a predetermined density image display means.), And the photographer may be allowed to make a judgment on good or bad based on the displayed image. Here, the extraction of the image data can be performed by the pass / fail judgment unit 15, and the pass / fail judgment unit 15 also functions as an image data extraction unit.

As described above, if the configuration is such that actual image information, determination data, or a portion of a predetermined density range is extracted and displayed on the display device, and the photographer determines acceptability based on the information, When the automatic determination is performed according to the above-described determination criterion, the histogram of the image data after the processing, even in the case where the determination is good, when the processing different from the photographer's intention is performed. , Can be determined to be defective.

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

In this case, by resetting the gradation processing conditions to those suitable for the high-pressure imaging, radiation image information intended by the high-pressure imaging can be obtained (FIGS. 8A and 8B). b)). Further, as shown in FIGS. 9 (a) and 9 (b), when processing is performed so that the histogram is distributed over the entire range by gradation processing even though the imaging has failed due to an excessive dose, And the gradation processing has succeeded, but the success of the gradation processing makes a good determination. Also in this case, by providing the determination information, the photographer can make a correct determination.

As described above, depending on the photographing intention of the photographer, the fact that the histogram of the processed image data is distributed over a wide range does not necessarily indicate that the desired image data has been obtained. Therefore, the photographing intention of the photographer (high-voltage photographing, low-voltage photographing, wanting to observe a specific part, etc.) can be set in advance in the pass / fail judgment system.
Detects data (such as overall contrast, output density value of a specific portion, etc.) or an image portion that is convenient for determining whether or not the image is processed according to a preset photographing intention, and provides the photographer with the photographed image. May be made to determine the quality.

Specifically, photographing intentions such as high-voltage photographing, low-pressure photographing, and observation of a specific part are set in advance, and data (the overall contrast,
The pass / fail determination unit 15 corresponding to the discrimination information detecting means detects an image portion reflecting the output density value of the specific part and the intention thereof, and displays the detection result on the display device 16 (this function is used to determine the photographing intention. This is equivalent to a display unit.), And allows the photographer to make a pass / fail judgment based on the displayed information.

In this way, although many tissues are intended to be displayed on one image by, for example, high-pressure photographing, image data is obtained by gradation processing as shown in FIGS. 7 (a) and 7 (b). If the processing for distributing widely is performed and the gradation processing is successful, but the photographing intention cannot be achieved, the photographer is notified that the processing corresponding to the intended high-pressure photographing is not performed based on the information. Can be determined. Therefore, a radiation image intended by the photographer can be obtained by resetting the processing conditions suitable for high-pressure imaging and performing reprocessing (see FIGS. 8A and 8B).

Here, when the high-pressure shooting or the low-pressure 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-pressure shooting or the low-pressure shooting is performed in advance. The gradation process may be performed with a characteristic that conforms to the above, and the pass / fail judgment may be performed by changing the reference level of the automatic pass / fail judgment accordingly. By the way, when a defect is determined as described above,
Based on a comparison between the histogram of the image data after the image processing based on which the defect is determined and the characteristic that is determined to be good, how to change the characteristic of the gradation processing so that the good determination is made Can be determined. Therefore, the reprocessing condition determination unit
At 17, the following reprocessing conditions are determined according to the item determined to be defective by receiving the determination information of the pass / fail determination unit 15, and the image data is processed by the reprocessing unit 18 based on the determined reprocessing conditions. Is reprocessed, it is possible to obtain image data that is finally determined to be good.

The reprocessing condition determining unit 17 and the reprocessing unit
At 18, the image data reprocessing means is constituted. "Reprocessing conditions" 1) Data of 30% or more of the entire image has an output density of 1.0 to 2.
0 (concentration range effective for diagnosis; can be set for each device).

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

[Reprocessing] → Perform processing to distribute widely. 3) When the minimum value of the image data of the entire image is not less than or equal to the output density 0.5 (density invalid for diagnosis; settable for each device). [Reprocessing] → Perform processing to shift to the low density side. 4) The maximum value of the image data is not higher than the output density of 2.5 (density invalid for diagnosis; settable for each device).

[Reprocessing] → Perform processing to shift to the high density side. 5) The case where the minimum value of the image data before processing is not more than the reference signal value (signal value invalid for diagnosis; settable for each device). [Reprocessing] → Perform processing to shift to the high density side. 6) When the maximum value of the image data before processing is not less than the reference signal value (a signal value invalid for diagnosis; settable for each device).

[Reprocessing] → Perform processing to shift to the low density side. 7) 80% or more of the data in the region (region of interest) set for setting the gradation processing conditions corresponds to an output density of 1.0 to 2.0 (a density range effective for diagnosis; settable for each device). If not in range. (Reprocessing) → Image data in the region of interest is output density 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 of 1.0
To 2.0 (concentration range effective for diagnosis; settable for each device) When the mode value in the histogram of data within the range corresponding to 1 is set to 1, an 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] → Perform processing to narrow the region of interest. 9) The maximum value of the image data in the region (region of interest) set for setting the gradation processing conditions is such that the output density is 1.5 to 2.5.
(Can be set for each device). [Reprocessing] → Perform processing to shift to the high density side.

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 not within the range corresponding to 0.5 to 1.5 (can be set for each device). [Reprocessing] → Perform processing to shift to the low density side. 11) When the variance of the image data in the region (region of interest) set for setting the gradation processing condition is not within a certain range.

[Reprocessing] → When the variance is small (when the contrast is high), a process for reducing the contrast is performed. Conversely, when the variance is high (when the contrast is low), the contrast is high. The following processing is performed. 12) When the minimum value of the pre-processing image data in the region (region of interest) set for setting the gradation processing condition is not more than the reference signal value (signal value invalid for diagnosis; can be set for each device) .

[Reprocessing] → Perform processing to shift to the high density side. 13) When the maximum value of the unprocessed image data in the region (region of interest) set for setting the gradation processing condition is not less than the reference signal value (signal value invalid for diagnosis; settable for each device) . [Reprocessing] → Perform processing to shift to the low density side.

As described above, even if the image data determined to be defective is reprocessed again, if the defect is determined again, it is determined that there is a defect in the shooting conditions that cannot be compensated for by the image processing. From the distribution of the density values of the image data before processing, the extent to which the imaging condition (dose / tube voltage) needs to be adjusted is displayed on the display device 16 as data, and adjusted to the photographer. The data may be provided (this function corresponds to the re-input condition notifying means), or the photographing conditions may be automatically set and the photographing may be performed again.

[0073]

As described above, according to the present invention, the distribution of density values of image data after image processing is represented.
By detecting the data to be processed and judging the quality of the processed image data based on the detection result, even if there is a defect in the imaging conditions, the defect is compensated by the image processing to obtain good radiation image data. In such a case, unnecessary re-imaging can be avoided, and even if the imaging is performed well, if the desired radiation image cannot be obtained due to inadequate processing conditions, re-processing is performed by changing the processing conditions. There is an effect that it becomes possible to perform the above-mentioned treatment.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing a distribution state of image data when both shooting and processing have been successfully performed.

FIG. 4 is a diagram showing a distribution state of image data when a shooting defect is compensated for by image processing.

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

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

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

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

FIG. 9 is a diagram illustrating an example of a case where an image is determined to be apparently good by image processing even though imaging has failed.

FIG. 10 is a view 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]

 Reference Signs List 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 judgment device 13 Histogram creation unit 14 Histogram analysis unit 15 Pass / fail Judgment unit 16 Display unit 17 Reprocessing condition determination unit 18 Reprocessing unit

Continuation of front page (56) References JP-A-3-102478 (JP, A) JP-A-3-218578 (JP, A) JP-A-3-167677 (JP, A) JP-A-3-345172 (JP) JP-A-3-51891 (JP, A) JP-A-1-256935 (JP, A) JP-A-4-212949 (JP, A) JP-A-62-242286 (JP, A) JP-A-62-28649 60-37878 (JP, A) JP-A-3-206572 (JP, A) JP-A-3-107135 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 6/00 -6/14

Claims (8)

(57) [Claims] 1. A image processing means for performing image processing on the image data of each part of the transmission to radiation transmission amount to the radiation image that has been formed corresponding object, the image data subjected to image processing by said image processing means Concentration of
Distribution state detecting means for detecting data representative of the distribution state of the value ; and a density value of the image data detected by the distribution state detecting means .
Data representing the distribution state , based on a comparison between the data and the expected value of the data, determine whether the image data is good or bad after processing by the image processing means, and pass / fail judgment means for outputting a pass / fail judgment signal. A radiation image processing apparatus comprising: 2. The image processing means sets an image area for determining image processing conditions by analyzing image data of a radiation image formed corresponding to the amount of radiation transmitted through each part of the subject. Area setting means; and image processing condition setting means for setting image processing conditions based on statistical properties of image data in the image area set by the area setting means; and the distribution state detecting means Is the distribution of density values of image data in the image area set by the area setting means in the image data subjected to image processing by the image processing means.
2. The radiation image processing apparatus according to claim 1, wherein data representing a state is detected. 3. An image data detected by said distribution state detecting means.
The data representative of the distribution state of the data density values include the maximum value of the density values of the image data , the minimum value of the density values of the image data , the parameter indicating the degree of dispersion of the density values of the image data , and the predetermined density range. and percentage of the image data to be distributed within the predetermined a concentration range parameter indicating the degree of dispersion of the image data to be distributed in the, and the maximum value of the density values of the unprocessed image data, the minimum value of the density values 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 following. Wherein when the defective image data after image processing on the basis of the quality determination signal is discriminated, the detected image
The image processed by the image processing means in the direction in which the quality is determined by the quality determination means based on a comparison between the data representing the distribution state of the density value of the data and the expected value used in the quality determination. 4. The radiation image processing apparatus according to claim 1, further comprising an image data reprocessing unit for reprocessing data. 5. The image processing apparatus according to claim 1, wherein said distribution state detecting means detects a density value of the image data reprocessed by said image data reprocessing means.
Data representative of the cloth state is detected, and if the pass / fail determination unit determines again as defective based on the data, it is determined that the image data input to the image processing unit is defective. 5. A re-input condition notifying means for notifying data indicating an appropriate input condition is provided.
The radiation image processing apparatus according to claim 1. 6. A density value of image data detected by said distribution state detecting means instead of said pass / fail determination means.
4. A quality information display means for displaying data representative of the distribution state of the image data as information for determining the quality of the processed image data. A radiation image processing apparatus according to claim 1. 7. 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, and image data subjected to image processing by said image processing means. From
Image data extracting means for extracting image data within a range corresponding to a predetermined output density range set in advance; and only the image portion composed of the image data extracted by the image data extracting means is processed. A radiographic image processing apparatus, comprising: a predetermined density image display means for displaying as information for judging pass / fail. 8. 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, and image data subjected to image processing by said image processing means. From
An image portion preset as an area to be observed and an image
Image data set in advance for use in determining the processing result
Discrimination information detection means for detecting information for detecting at least one of the characteristic representative value of the density value, and whether the image data after processing of the information detected by the discrimination information detection means corresponds to the photographing intention. A radiographic image processing apparatus comprising: an imaging intention determination display unit that displays information as information for determining whether or not the imaging intention is determined.