JP2001222084A - Image processor and medical image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the degradation in diagnosis performance by making it possible to express a radiation image region as an image near to its end, and reflecting the part exclusive of the radiation image region thereby generated within the images with high luminance. SOLUTION: The image processor, which obtains the images inclusive of the radiation image region by the radiation past a subject, has a radiation image region recognizing means 100 which recognized the radiation image region from the images inclusive of the radiation image region, and a prescribed density output means 101 exclusive of the radiation image region which outputs the region exclusive of the radiation image region recognized by this radiation image region recognizing means 100. Also, the image processor which obtains the images inclusive of the radiation image region by the radiation past the subject has the radiation image region recognizing means 100 which recognizes the radiation image region from the images inclusive of the radiation image region and a trimming means 102 exclusive of the radiation image region which trims and outputs the region exclusive of the radiation image region recognize by the radiation image region recognizing means 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and a medical image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject.

[0002]

2. Description of the Related Art In recent years, devices capable of directly taking a radiation image as a digital image have been developed. For example, as a device that detects the amount of radiation applied to a subject and obtains a radiation image formed in accordance with the detected amount as an electric signal, a method using a detector using a stimulable phosphor is disclosed in Japanese Patent Application Laid-Open No. H10-163,873. No. 55-12429, JP-A-63-18985
Many publications such as Japanese Patent Publication No. 3 are disclosed. In such an apparatus, a stimulable phosphor is applied to a sheet-like substrate, or a detector fixed by vapor deposition or the like is once irradiated with radiation that has passed through a subject, so that the stimulable phosphor absorbs the radiation. Then, by exciting the stimulable phosphor with light or heat energy, the radiation energy accumulated by absorption by the stimulable phosphor is emitted as fluorescence, and the fluorescence is photoelectrically converted to form an image signal. I'm trying to get.

On the other hand, an electric charge corresponding to the intensity of the irradiated radiation is generated in a photoconductive layer, the generated electric charge is stored in a plurality of two-dimensionally arranged capacitors, and the stored electric charge is taken out. Has been proposed. Such a radiation image detecting apparatus uses what is called a flat panel detector (FPD). This type of FPD is disclosed in JP-A-9-90.
As described in Japanese Patent Application Publication No. 048, fluorescence can be detected by a photodiode or a CCD or C-MOS sensor. A similar FPD is described in Japanese Patent Application Laid-Open No. 6-342098.

In these apparatuses, usually, in order to avoid unnecessary exposure to the human body during radiography, radiographing is performed by limiting the area to be irradiated with radiation using a radiation shield called an irradiation field stop. Since the signal distribution greatly changes inside and outside the radiation image area, the image reading control unit reads the inside of the radiation image area.

[0005]

By the way, in radiography used for diagnosis, a region to be imaged covers a wide range from the head to the limbs, and a doctor's area of interest differs for each. Especially in mammogram photography, when printing on film and observing, the chest wall side of the radiation image area is to be observed closer to the chest wall, so the image is read in order to be able to read to the chest wall side image edge. It is conceivable to shift the reading area by shifting or widening the area. In this case, the reading area includes something other than the image area generated by the radiation, that is,
An image including the area outside the radiation image area is output. On the film, the area outside the radiation image area is output at a low density.

When the image is output so that the area outside the radiation image area is included in the image, when the film is observed on the display device, the area outside the radiation image area is displayed with high brightness. There is a danger that the region unnecessary for the diagnosis is dazzling and the diagnostic performance of the radiation image region is deteriorated.

The present invention has been made in view of the above circumstances, and it is possible to express an image up to the vicinity of an end of a radiographic image area, and a portion outside the radiographic image area caused by this is provided with high luminance. The purpose of the present invention is to prevent the diagnostic performance from being lowered by being included in an image.

[0008]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to a first aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image region generated by radiation passing through a subject, wherein the image processing device converts the radiation image region from the image including the radiation image region. An image processing apparatus comprising: a radiation image area recognizing means for recognizing; and a radiation image area predetermined density output means for outputting an area other than the radiation image area recognized by the radiation image area recognizing means at a predetermined density. . ].

According to the first aspect of the present invention, a radiographic image area is recognized from an image including the radiographic image area, and an area other than the recognized radiographic image area is output at a predetermined density, thereby achieving image processing. If not performed, the outside of the radiation image area that is dazzlingly output with high brightness can be prevented from being dazzling, so that it is possible to accurately diagnose up to the vicinity of the end of the radiation image area. Therefore, diagnostic performance is improved.

According to a second aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image region generated by radiation passing through a subject, wherein the image processing device converts the radiation image region from the image including the radiation image region. An image processing apparatus comprising: a radiation image area recognizing means for recognizing; and a radiation image area trimming means for trimming and outputting an area other than the radiation image area recognized by the radiation image area recognizing means. ].

According to the second aspect of the present invention, the radiographic image area is recognized from the image including the radiographic image area, and the area other than the recognized radiographic image area is trimmed and output. If the image is not output as the image area, the area outside the radiation image area that is brightly output with high brightness is not output as the image area, so that the diagnosis can be accurately performed up to the vicinity of the end of the radiation image area. Therefore, diagnostic performance is improved.

According to a third aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, wherein the image processing apparatus converts the radiation image area from the image including the radiation image area. A radiation image area recognizing means for recognizing, a radiation image area predetermined density output means for outputting an area other than the radiation image area recognized by the radiation image area recognizing means at a predetermined density; A radiation image area outside trimming means for trimming and outputting an area other than the radiation image area, and outputting the radiation image area outside at a predetermined density by the radiation image area outside predetermined density output means or the radiation image outside trimming means. Output method selecting means for selecting whether to output by trimming according to Image processing apparatus. ].

According to the third aspect of the present invention, it is possible to select whether to output at a predetermined density outside the radiation image area or to output after trimming, so that flexible output according to the situation is possible. is there.

According to a fourth aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, wherein a threshold of pixels of the image including the radiation image area is determined. A threshold setting unit for setting a value; and a threshold or lower pixel predetermined density output unit for outputting, at a predetermined density, pixels lower than the threshold set by the threshold setting unit. Image processing device. ].

According to the fourth aspect of the present invention, pixels lower than the set threshold value (low density or low luminance) are output at a predetermined density, and an optimum threshold value is determined for each image. By doing so, it is possible to prevent the area required for diagnosis from being output at a predetermined density, and to improve the diagnostic performance.

According to a fifth aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image region generated by radiation passing through a subject, wherein a threshold of pixels of the image including the radiation image region is defined. Image processing comprising: threshold value setting means for setting a value; and threshold value or less pixel trimming means for trimming and outputting pixels lower than the threshold value set by the threshold value setting means. apparatus. ].

According to the fifth aspect of the present invention, a pixel lower than the set threshold value is trimmed and output,
By determining the optimum threshold value for each image, it is possible to prevent the area necessary for the diagnosis from being trimmed, and to improve the diagnostic performance.

According to a sixth aspect of the present invention, there is provided an image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, wherein a threshold of pixels of the image including the radiation image area is determined. Threshold value setting means for setting a value; a threshold value or less pixel predetermined density output means for outputting a pixel lower than the threshold value set by the threshold value setting means at a predetermined density; Below-threshold pixel trimming means for trimming and outputting pixels lower than the threshold value set by the above-mentioned threshold value; An output method selection unit that can select whether to output by trimming by the unit. 』
It is.

According to the sixth aspect of the present invention, since it is possible to select whether to output at a predetermined density or to output after trimming, flexible output according to the situation is possible.

According to a seventh aspect of the present invention, there is provided the radio communication apparatus according to the first aspect, wherein the threshold value setting means has a radiation image area recognizing means for recognizing a radiation image area. 7. The method according to claim 4, wherein the determination is made based on a minimum value of
An image processing apparatus according to the item. ].

According to the present invention, the radiation image area is recognized, and the threshold value is determined using the minimum value of the area. It is possible to reduce the possibility that the output is performed after the density or the trimming, and the diagnostic performance can be improved.

According to an eighth aspect of the present invention, there is provided a radiographic image processing apparatus comprising: a radiographic image area recognizing means for recognizing a radiographic image area; The cumulative histogram creating means for creating a histogram, and the histogram is determined by a predetermined ratio determined from the cumulative histogram created by the cumulative histogram creating means. Image processing device. ].

According to the eighth aspect of the present invention, by recognizing the inside of the radiation image area and determining the threshold value using a predetermined ratio of the cumulative histogram of the area,
Unnecessary areas in the radiation image area can also be output at a predetermined density, and the diagnostic performance can be further improved.

According to a ninth aspect of the present invention, there is provided a method as set forth in any one of claims 4 to 8, wherein a threshold value changing means for changing a threshold value determined by said threshold value setting means is provided. The image processing apparatus according to claim 1. ].

According to the present invention, when the threshold value determined by the threshold value setting means is not appropriate, the possibility of failure can be reduced by changing the threshold value. In addition, the diagnostic performance can be improved.

According to a tenth aspect of the present invention, there is provided an image processing apparatus according to any one of the first to ninth aspects, further comprising: an image processing apparatus for obtaining an image including a radiation image area generated by radiation passing through a subject. A medical image processing apparatus comprising: ].

According to the tenth aspect of the present invention, it is possible to express an image up to the vicinity of the end of the radiation image area, and to acquire an image including a radiation image area generated by radiation passing through the subject. can do.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the description of the embodiments and the drawings.

FIG. 1 is a diagram showing the configuration of the image processing apparatus. The radiation generator 30 is controlled by the controller 10, and the radiation emitted from the radiation generator 30 is applied to the imaging panel mounted on the front of the radiation image reader 40 through the subject 5.

FIG. 2 shows the structure of the image pickup panel. The imaging panel 41 has a substrate having a thickness enough to obtain a predetermined rigidity, and a detection element 412 that outputs an electric signal in accordance with the dose of the irradiated radiation is provided on the substrate.
_{-(1,1) to} 412- _{(m, n)} are two-dimensionally arranged. Also,
Scan lines 415 _{-1 to} 415 _-m and signal lines 416 _{-1 to} 416 _-n
Are arranged, for example, orthogonally.

The scanning line 415 of the imaging panel 41_-1~ 415
_-mAre connected to the scanning drive unit 44. Scan driver 4
4 to scanning line 415_-1~ 415_-mOne of the scan lines 4
Fifteen _-p(P is any value from 1 to m)
When S is supplied, this scanning line 415_-pThe test connected to
Electrical signal S corresponding to the dose of radiation emitted from the output element
V_-1~ SV_-nIs detected, and the signal line 416 is detected._-1~ 416_-nTo
The image data is supplied to the image data generation unit 46 via the image data generation unit 46.

The detection element 412 may be any element that outputs an electric signal corresponding to the dose of the irradiated radiation. For example, when a detection element is formed using a photoconductive layer in which an electron-hole pair is generated upon irradiation with radiation and the resistance value changes, an amount corresponding to the amount of radiation generated in the photoconductive layer is used. Is stored in the charge storage capacitor, and the charge data stored in the charge storage capacitor is supplied to the image data generator 46 as an electric signal. The photoconductive layer desirably has a high dark resistance value, and is preferably amorphous selenium, lead oxide, cadmium sulfide, mercuric iodide,
Or, a photoconductive organic material (including a photoconductive polymer to which an X-ray absorbing compound is added) is used,
Particularly, amorphous selenium is desirable.

When the detection element 412 is formed using, for example, a scintillator or the like that generates fluorescence when irradiated with radiation, a photodiode generates an electric signal based on the intensity of the fluorescence generated by the scintillator. The information may be supplied to the image data generator 46. The image data generation unit 46 sequentially selects the supplied electric signals SV based on the output control signal SC from the reading control unit 48 and converts them into digital image data DT. The image data DT is supplied to the reading control unit 48.

The reading control unit 48 is connected to the controller 10.
In the reading control unit 48, the controller 10
Scanning control signal R based on the control signal CTD supplied from
C and an output control signal SC are generated. This scanning control signal C
The scan control signal is supplied to the scan drive unit 44 based on the TD to control the scan.
Scan line 415 based on signal RC_-1~ 415_-mAgainst
The supply of the read signal RS is performed. Further, the output control signal S
C is supplied to the image data generator 46. This reading control
The scanning control signal RC and the output control signal SC from the section 48
Therefore, for example, the imaging panel 41 is (m × n) as described above.
When the detection element 412 is used, the detection element
Child 412_-(1,1)~ 412_{-(m, n)}Based on the electric signal SV from
Data DP_(1,1)~ DP_{8m, n)}Then
Data DP _(1,1), DP_(1,2), ... DP_{(1, n)}, D
P_(2,1), ..., DP_{(m, n)}Image data as order
DT is generated, the image data is generated, and
The image data DT is transferred from the image data generation unit 46 to the reading control unit.
48. Also, the reading control unit 48
Processing for transmitting image data DT to the controller 10 is also performed.
U.

The image data DT obtained by the radiation image reader 40 is supplied to the controller 10 via the reading control section 48. When the image data obtained by the radiation image reader 40 is supplied to the controller 10 and the log-converted image data is supplied, the controller 10
Can simplify the processing of the image data.

The radiation image reader 40 is not limited to the one using the FPD, but may use a stimulable phosphor. FIG. 3 shows a configuration in which a radiation image reader 60 using a stimulable phosphor is used. In a conversion panel 61 to which radiation is irradiated, a stimulable phosphor layer is formed on a support. It is provided by a vapor phase deposition of a stimulable phosphor or a stimulable phosphor paint. This stimulable phosphor layer is shielded or covered by a protective member in order to block adverse effects and damage due to the environment.

The light beam generator (gas laser, solid laser, semiconductor laser, etc.) 62 generates a light beam whose emission intensity is controlled. This light beam reaches the scanning unit 63 via various optical systems, is deflected by the scanning unit 63, is further deflected by the reflecting mirror 64, and is guided to the conversion panel 61 as stimulating excitation scanning light. .

At the light-collecting end of the light-collecting body 65 formed of an optical fiber or a sheet-like light guide member, stimulating light excitation light is guided as scanning light. The light-collecting end of the light-collecting body 65 formed of an optical fiber or a sheet-shaped light guide member is disposed close to the conversion panel 61 on which the stimulating light is scanned, and scans the light beam from the light beam generator 62. As a result, stimulated emission having an emission intensity proportional to the latent image energy generated in the conversion panel 61 is received.

The filter 66 passes only light in the stimulating emission wavelength region from the light introduced from the light collector 65, and the light passing through the filter 66 is incident on the photomultiplier 67. The photomultiplier 67 generates a current signal corresponding to incident light by photoelectric conversion. This current signal is supplied to the current / voltage converter 70 and converted into a voltage signal. Further, after the voltage signal is amplified by the amplifier 71, the voltage signal is converted into digital image data DT by the A / D converter 72. Here, a logarithmic conversion amplifier (log amplifier) is used as the amplifier 71. The image data DT is sequentially image-processed in the image processing device 80, and the image data DTC after the image processing is transmitted to the printer 83 via the interface 82.

CPU (Central Process)
ing Unit) 81 is for controlling image processing in the image processing device 80,
In the case of 0, various image processings (for example, spatial frequency processing, dynamic range compression, gradation processing, enlargement / reduction, movement, rotation, statistical processing, etc.) are performed on the image data DT, and an image in a form suitable for diagnosis is performed. Generate data DTC. This image data DTC is supplied to the printer 83 and
From 3, a hard copy of the radiation image of each part of the human body can be obtained. Note that a monitor such as a CRT may be connected to the interface 82, and a storage device (filing system) capable of storing image data of a plurality of radiation images (filing system) may be connected.

The reading controller 75 adjusts the light beam intensity of the light beam generator 62, adjusts the gain of the photomultiplier 67 by adjusting the power supply voltage of the high-voltage power supply 76 for the photomultiplier, and amplifies the current / voltage converter 70. Part 71
Is adjusted, and the input dynamic range of the A / D converter 72 is adjusted, so that the reading gain is comprehensively adjusted. Image data DT obtained from the A / D converter 72
Is supplied to the controller 10 and controls the operation of the reading control unit 75 according to the control signal CTD from the controller 10.

The radiation image reader irradiates a silver halide film on which a radiation image is recorded with light from a light source such as a laser or a fluorescent lamp, and photoelectrically converts the transmitted light of the silver halide film to generate image data. May be. Further, a configuration may be employed in which radiation energy is directly converted into an electric signal using a radiation quantum counting type detector to generate image data.

Next, the configuration of the controller 10 is shown in FIG. CPU for controlling operation of controller 10
(Central Processing Unit)
11 is connected to a system bus 12 and an image bus 13, and an input interface 17. CPU 11 for controlling the operation of this controller 10
The operation of is controlled based on a control program stored in the memory 14. System pulse 12 and image bus 13
Are connected to a display control unit 15, a frame memory control unit 16, an output interface 18, a shooting control unit 19, a disk control unit 20, and the like. The transfer of image data between the units via the image bus 13 is performed.

A frame memory 21 is connected to the frame memory control unit 16, and image data obtained by the radiation image reader 40 is stored via the imaging control unit 19 and the frame memory control unit 16. The image data stored in the frame memory 21 is read and supplied to the display control unit 15 and the disk control unit 20. The frame memory 21 may store the image data supplied from the radiation image reader 40 after the CPU 11 processes the image data.

An image display device 22 is connected to the display control unit 15, and a radiographic image based on the image data supplied to the display control unit 15 is displayed on the screen of the image display device 22. Here, when the number of display pixels of the image display device 22 is smaller than the number of pixels of the radiation image reader 40, the entire captured image can be displayed on the screen by thinning out and reading out the image data. In addition, if the image data of the area corresponding to the number of display pixels of the image display device 22 is read out, the captured image at the desired position can be displayed in detail.

From the frame memory 21 to the disk controller 2
When the image data is supplied to the disk controller 20, for example, the image data is read continuously and
The data is written to the O memory, and then sequentially recorded on the disk device 23. Further, image data read from the frame memory 21 or image data read from the disk device 23 can be supplied to the external device 100 via the output interface 18.

In the image processing section 26, the radiation image reader 4
0 to the image data D supplied via the photographing control unit 19
T irradiation field recognition processing, region of interest setting, normalization processing, gradation processing, and the like are performed. Further, frequency emphasis processing, dynamic range compression processing, and the like may be performed. In addition, as a configuration in which the CPU 11 also serves as the image processing unit 26,
Image processing and the like can also be performed.

The input interface 17 is connected to an input device 27 such as a keyboard. By operating the input device 27, management information such as information for identifying image data obtained by shooting and information on shooting is input. As the external device 90 connected to the output interface 18, a scanning laser exposure device also called a laser imager is used. In this scanning laser exposure apparatus, the intensity of a laser beam is modulated by image data, exposed to a conventional silver halide photographic material or a thermal phenomenon silver halide photographic material, and then subjected to an appropriate development process to thereby produce a radiation image. A hard copy is obtained.

Although the frame memory 21 stores the image data supplied from the radiation image reader 40, the image data supplied may be processed by the CPU 11 and then stored. Further, the disk device 23 stores image data stored in the frame memory 21, that is, image data supplied from the radiation image reader 40 and image data obtained by processing the image data by the CPU 11 together with management information and the like. be able to.

Next, the operation will be described. When obtaining a radiation image of the subject 5, it is assumed that the subject 5 is located between the radiation generator 30 and the imaging panel 41 of the radiation image reader 40, and the radiation emitted from the radiation generator 30 is And is incident on the radiation image capturing panel 41 transmitted through the subject 5. In addition, since the radiation image reader 40 is used instead of the radiation image reader 40, the description of the case where the radiation image reader 60 is used is omitted.

Using the input device 27, the controller 10 receives management information indicating the identification of the subject 5 to be photographed and information relating to the photographing. The input of the management information using the input device 27 is performed by operating a keyboard, using a magnetic card, a bar code, an HIS (In-Hospital Information System: information management by network), and the like.

The management information includes, for example, an ID number, a name,
Date of birth, gender, date and time of imaging, location and position of imaging (for example, which part of the human body was irradiated with radiation from which direction), imaging method (simple imaging, contrast imaging, tomography, magnified imaging, etc.), imaging It consists of information such as conditions (tube voltage, tube current, irradiation time, use of scattered radiation removal grid, etc.).

The date and time of photographing can be obtained automatically from the CPU 11 by using a clock function built in the CPU 11. The management information to be input may be only information relating to the subject to be photographed at that time. A series of management information may be input in advance, and the subject may be photographed in the input order, or the management information may be input as needed. The information may be read and used.

When the power switch of the radiation image reader 40 is turned on, a control signal C from the controller 10 is output.
Based on the TD, the reading control unit 48 of the radiation image reader 40
The scanning panel 44 initializes the imaging panel 41. This initialization is for obtaining a correct electric signal corresponding to the radiation dose emitted from the imaging panel 41.

When the initialization of the image pickup panel 41 is completed in the radiation image reader 40, irradiation of radiation from the radiation generator 30 is enabled. Here, when a switch for irradiating radiation is provided in the radiation generator 30, when the switch is scanned, the radiation
Radiation is irradiated for a predetermined time, and a signal DFS indicating the start of irradiation and a DFE indicating the end of irradiation
Is supplied to the controller 10.

At this time, the radiation dose of the radiation applied to the imaging panel 41 of the radiation image reader 40 is modulated by the subject 5 because the degree of radiation absorption by the subject 5 differs. Detection element 412 of imaging panel 41- _(1,1)
In ４ 412- _{(m, n)} , an electric signal based on the radiation modulated by the subject 5 is generated.

Next, in the controller 10, after a predetermined time from the supply of the signal DFS, for example, when the irradiation time of the radiation is about 0.1 second, a time longer than the irradiation time (for example, about 1 second) elapses. Or immediately after the signal DFE is supplied, the radiation image reader 40 outputs the image data D
The control signal CTD is supplied to the reading control unit 48 of the radiation image reader 40 to start generation of T.

On the other hand, when a switch for irradiating radiation is provided in the controller 10, when this switch is operated, an irradiation start signal CST for starting irradiation of radiation is transmitted via the imaging control unit 19. The radiation is supplied to the radiation generator 30, and the radiation is emitted from the radiation generator 30 toward the subject 5 for a predetermined time. The irradiation time is set based on, for example, management information.

Next, the controller 10 outputs a control signal CT for starting the generation of image data by the radiation image reader 40 a predetermined time after outputting the irradiation start signal CST.
D is supplied to the reading control unit 48 of the radiation image reader 40. Note that the controller 10 detects the end of radiation irradiation by the radiation generator 30 and then sets the radiation image reader 4
Control signal CTD for starting generation of image data at 0
May be supplied to the radiation image reader 40.
In this case, generation of image data during irradiation of radiation can be prevented.

The reading controller 48 of the radiation image reader 40 generates a scanning control signal RC and an output control signal SC based on a control signal CTD for starting generation of image data supplied from the controller 10. The scanning control signal RC is supplied to the scanning driving unit 44, and the output control signal SC is supplied to the reading control unit 48 with the image data DT. This image data DT is sent to the controller 10 by the reading control unit 48.

The image data DT supplied to the controller 10 is stored in the frame memory 21 via the photographing control unit 19, the frame memory control unit 16 and the like. Using the image data stored in the frame memory 21, a radiographic image can be displayed on the image display device 22. Further, by supplying the image data stored in the frame memory 21 to the display control unit 15, the brightness, contrast, sharpness, and the like are adjusted, and a radiation image suitable for diagnosis or the like can be displayed. Further, by supplying the image data on which the image processing has been performed to an external device 90 such as a laser film printer, a hard copy of a radiation image suitable for diagnosis or the like can be obtained. Further, a soft copy may be obtained by outputting to an image display device such as a CRT, a liquid crystal display, and a plasma display.

In the image processing unit 26, even if the level distribution of the image data output from the imaging panel 41 fluctuates due to the difference in the radiation dose, the image data is always obtained so that a stable radiation image can be obtained. DT normalization processing is performed. Further, even if the distribution of image data levels fluctuates, gradation processing is performed in order to obtain a radiation image having a suitable density and contrast for diagnosis or the like. Further, the image processing unit 26 performs frequency emphasis processing for controlling the sharpness of the normalized radiation image, the multi-resolution method disclosed in Japanese Patent Application Laid-Open No. 9-44645, or the entire dynamic radiation image with a wide dynamic range. A dynamic range compression process may be performed to reduce the contrast of the structural portion to a range that is easy to see without lowering the contrast.

The radiation image reader 40 shown in FIGS. 1 and 4
Then, an image including the outside of the radiation image area is read and output. For example, in radiography used for diagnosis, the region to be imaged covers a wide range from the head to the limbs, and the area to which the doctor pays attention differs depending on each area. In order to be able to read up to the end of the chest wall side image, the reading area of the imaging panel 41 or the reading control unit 48 may be changed or the reading position may be changed by widening the reading area in order to be able to read the image near the chest wall side.

Thus, in mammogram photography,
As shown in FIG. 5, the chest wall side is an area of interest, and an image including an area A outside the radiation image area can be output. it can.

When the image is printed on a film and output or displayed on a display such that the area A outside the radiation image area is included in the image, the area outside the radiation image area is displayed with high luminance. That is, when a doctor makes a diagnosis, a region A unnecessary for the diagnosis, which is displayed with high luminance, is dazzling, and the diagnostic performance of the radiation image region B may be deteriorated.

For this reason, as shown in FIG. 6, the image processing apparatus according to the present invention employs a radiation image area recognizing means 100 for recognizing a radiation image area B from an image including the radiation image area B.
And a predetermined density outside the radiation image area 101 for outputting the area A other than the radiation image area recognized by the radiation image area recognition means 100 at a predetermined density. Recognizing the radiation image area B from the image including the radiation image area B,
An area A other than the recognized radiation image area is output at a predetermined density. The predetermined density is such that the area A other than the radiation image area is low in brightness and not dazzling when displaying and diagnosing.

As described above, by outputting the area A other than the radiation image area at a predetermined density, the area A other than the radiation image area becomes less dazzling with low luminance, and the strong contrast at the boundary between the area A and the area B disappears. , Radiation image area B
It is possible to easily observe accurately up to the vicinity of the end of.

In particular, in the case of a mammogram, as shown in FIG. 12, when two images in the same photographing direction are output as one image so as to face each other, high brightness (low brightness) is output between the two images. Since there is no area of high density, comparative image interpretation becomes easy, and improvement in diagnostic performance can be expected. FIG. 12A is a photograph taken by imaging in the MLO direction (direction in which the breast is obliquely sandwiched) of the left and right pectoral muscle regions, and FIG.
Are images taken in the CC direction of the left and right pectoral muscle regions (directions in which the breast is sandwiched vertically).

As shown in FIG. 7, the image processing apparatus according to the present invention comprises a radiation image area recognizing means 100 for recognizing a radiation image area B from an image including the radiation image area B;
A radiation image area trimming means 102 for trimming and outputting an area A other than the radiation image area recognized by the radiation image area recognition means 100 is provided. Since the radiation image area B is recognized from the image including the radiation image area B, and the area A other than the recognized radiation image area is trimmed and output, the area A other than the radiation image area is not output as an image. An area unnecessary for diagnosis is not output as a high-brightness and dazzling area. For this reason, the diagnostic performance of the radiation image area B is not reduced. Further, at the time of film output, a film having a smaller area can be used, so that the film can be saved, the developing solution can be saved, and the like.

In particular, in the case of a mammogram, as shown in FIG. 12, when two images in the same photographing direction are output as one image facing each other, the two images can be output closer. Therefore, comparative image reading becomes easy,
Improvement of diagnostic performance can be expected.

As shown in FIG. 8, the image processing apparatus according to the present invention comprises a radiation image area recognizing means 100 for recognizing a radiation image area B from an image including the radiation image area B;
A predetermined density output unit 101 for outputting a region A other than the radiation image region recognized by the radiation image region recognizing unit 100 at a predetermined density, and a radiation image region other than the radiation image region recognized by the radiation image region recognizing unit 100 Radiation image area trimming means 102 for trimming and outputting area A, and predetermined density output means 101 outside the radiation image area
Output method selecting means 103 which can select whether to output a predetermined density outside the radiation image area or to trim and output the radiation image outside trimming means 102. The output method selection unit 103 selects, for example, by manually operating the operator, whether to output a predetermined density outside the radiation image area or to output the image after trimming, thereby enabling flexible output according to the situation.

Further, as shown in FIG. 9, the image processing apparatus according to the present invention includes a threshold setting unit 104 for setting a threshold of a pixel of an image including the radiation image area B, and a threshold setting unit. And a predetermined pixel density lower than pixel output means 105 for outputting a pixel lower than the threshold value set by 104 at a predetermined density. By determining an optimal threshold value for each image and outputting pixels having a lower density than the set threshold value at a low density, an area necessary for diagnosis is prevented from being output at a predetermined density and unnecessary. By not including a high-brightness area in the image, the diagnostic performance can be improved.

The image processing apparatus according to the present invention
As shown in (1), threshold value setting means 104 for setting a threshold value of a pixel of an image including the radiation image area B, and pixels lower than the threshold value set by the threshold value setting means 104 are trimmed. And a pixel trimming means 106 for outputting a threshold value or less. By trimming and outputting pixels lower than the set threshold value and determining the optimum threshold value for each image, it is possible to prevent the area necessary for diagnosis from being trimmed and to improve diagnostic performance. it can.

Further, the image processing apparatus of the present invention
As shown in (1), threshold value setting means 104 for setting a threshold value of a pixel of an image including the radiation image area B, and a pixel lower than the threshold value set by the threshold value setting means 104 at a predetermined density Below-threshold pixel predetermined density output means 105; below-threshold pixel trimming means 106 for trimming and outputting pixels lower than the threshold value set by threshold setting means 104; An output method selection unit 107 is provided which can select whether to output at a predetermined density by the pixel predetermined density output unit 105 or to output by trimming the pixel below the threshold value by the pixel trimming unit 106. The output method selection means 107 can select, for example, whether to output at a predetermined density or to output after trimming by manual operation of an operator, and thereby flexible output according to the situation is possible.

The threshold setting means 104 shown in FIGS. 9 to 11 determines the threshold based on the minimum value in the radiation image area recognized by the radiation image area recognition means 100. In this way, by recognizing the inside of the radiation image area and determining the threshold value using the minimum value of the area, the possibility of outputting the area required for diagnosis at a predetermined density is reduced, and the diagnostic performance is improved. be able to.

The threshold value setting means 104 includes a cumulative histogram creating means for creating a cumulative histogram in the radiation image area recognized by the radiation image area recognizing means 100, and a cumulative histogram created by the cumulative histogram creating means. The threshold is determined by a predetermined ratio determined from the following. In this way, by recognizing the inside of the radiation image region and determining the threshold using a predetermined ratio of the cumulative histogram of the region, unnecessary regions in the radiation image region can also be output at a predetermined density,
Further improvement in diagnostic performance is possible.

Further, there is provided a threshold value changing means 110 for changing the threshold value determined by the threshold value setting means 104. The threshold value changing means 110 is operated by an operator, for example. If the threshold determined by 104 is not appropriate, change the threshold,
As a result, the possibility of failure can be reduced, and diagnostic performance can be improved.

As described above, in the image processing apparatus of the present invention, the radiation image area B is recognized from the image including the radiation image area B, and the area A other than the recognized radiation image area is output at a predetermined density or trimmed. In this case, a certain threshold value is determined. In this case, an area below the threshold value is recognized as outside the radiation image area, and this area A is output at a predetermined density or output after trimming. May be.

At this time, as shown in FIG.
In this case, a look-up table may be created that outputs a pixel having a pixel value equal to or less than the threshold value P so as to have low luminance. Further, as shown in FIG. 14, when a predetermined pixel or less is displayed below the threshold value P, the image may be translated and output so as to have low luminance. Instead of outputting the image with low brightness, the image may be trimmed and output.

It is also possible to recognize the inside of the radiation image area and use the minimum value of the radiation image area as the threshold value P of the lookup table. As another method of determining the threshold value P after recognizing the inside of the radiographic image area, as shown in FIGS. 15 and 16, a cumulative histogram in the radiographic image area B is obtained, and then, at a predetermined rate. The threshold value P may be determined. The threshold value P of the cumulative histogram at this time
Is preferably 1% to 10%, but is not limited to this range.

In this case, as shown in FIG.
As shown in FIG. 17B, when there is a region A other than the radiation image region and an unnecessary region in the radiation image region, for example, a region C outside the irradiation field region where the radiation is irradiated (irradiation field), as shown in FIG. Only the area A other than the image area can be output at a predetermined density, or can be output after being trimmed as shown in FIG. In addition, as shown in FIG. 17C, an unnecessary area (for example, C outside the irradiation field area) in the radiation image area is output at a predetermined density, or trimmed and output as shown in FIG. Another effect is that it can be done.

When recognizing the inside of the radiographic image area, instead of outputting a value lower than the threshold value of the output look-up table at a predetermined density or trimming the output, the recognized area itself is used and the outside of the area is specified. Output in density,
Alternatively, the output may be trimmed.

In this case, as shown in FIG. 19A, when there is an area A other than the radiographic image area and an unnecessary area in the radiographic image area (for example, outside the irradiation field area C), FIG.
As shown in (b), when processing is performed using a threshold, an area D required for an image may be output at a predetermined density or may be output after being trimmed. May determine the minimum rectangular image area not including the recognized radiation image area, and output the other areas at a predetermined density. In this method, a high-brightness signal (low-density) in the radiation image area is not output at low-brightness (high-density). Nothing.

In the case of recognizing a radiation image area, since the radiation image area is a substantially constant area, the radiation image area is determined in advance as a constant area, and a temporal differentiation near the boundary is obtained. The radiation image area may be determined by the pixel having the largest value.

Since it is known that the outside of the radiographic image area appears at a fixed position on the chest wall side as shown in FIGS. 20 and 21, a horizontal profile is obtained and viewed from the image end on the chest wall side. First, a position where the value of the profile fluctuates greatly may be found, and the area opposite to the chest wall may be used as the radiation image area. It is desirable that the above-described gradation processing, frequency processing, and dynamic range compression processing be performed only in the radiation image area.

Further, the image processing apparatus shown in FIGS. 6 to 11 is further provided with a radiation image acquiring means 2 for acquiring an image including a radiation image area generated by radiation passing through the subject.
In this medical image processing apparatus, it is possible to express an image up to the vicinity of the end of the radiation image area, and further to obtain an image including a radiation image area generated by radiation passing through the subject. it can.

[0088]

As described above, claims 1 to 1 are as described above.
According to the invention described in No. 0, it is possible to express as an image up to near the end of the radiation image area,
Since the portion outside the radiation image area caused by this is reflected in the image with high luminance, it is possible to prevent the diagnostic performance from lowering.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an image processing apparatus.

FIG. 2 is a diagram illustrating a configuration of an imaging panel.

FIG. 3 is a diagram showing a configuration when a radiation image reader using a stimulable phosphor is used.

FIG. 4 is a diagram showing a configuration of a controller.

FIG. 5 is a diagram illustrating an example of an image including an area outside a radiation image area.

FIG. 6 is a diagram illustrating a configuration of an image processing apparatus.

FIG. 7 is a diagram illustrating a configuration of another image processing apparatus.

FIG. 8 is a diagram illustrating a configuration of another image processing apparatus.

FIG. 9 is a diagram illustrating a configuration of another image processing apparatus.

FIG. 10 is a diagram illustrating a configuration of another image processing apparatus.

FIG. 11 is a diagram illustrating a configuration of another image processing apparatus.

FIG. 12 is an image diagram of a typical mammogram photographing direction.

FIG. 13 is a diagram showing a look-up table for outputting at a predetermined density.

FIG. 14 is a diagram showing a lookup table that translates a predetermined pixel or less in parallel to a predetermined density by a predetermined number of pixels.

FIG. 15 is a diagram showing a radiation image area for creating a cumulative histogram of the radiation image area.

FIG. 16 is a diagram showing a cumulative histogram of a radiation image area.

FIG. 17 is a diagram showing an image after a predetermined density process.

FIG. 18 is a diagram showing an image after a trimming process.

FIG. 19 is a diagram showing an image after predetermined density processing.

FIG. 20 is a diagram illustrating recognition of an image including an area outside the radiation image area.

FIG. 21 is a diagram illustrating recognition of an image including an area outside a radiation image area.

[Explanation of symbols]

 A area outside radiation image area B radiation image area 100 radiation image area recognition means 101 predetermined density outside radiation image area output means 102 radiation image outside area trimming means 103 output method selection means 104 threshold setting means 105 pixels below threshold Predetermined density output means 106 Pixel trimming means below threshold

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisanori Dono 1 Sakura-cho, Hino-shi, Tokyo Konica Corporation F-term (reference) 2G083 AA03 AA04 BB05 EE01 EE03 2H013 AC06 4C093 AA16 AA28 CA18 CA21 FD03 FD09 FD20 FF16 FF19

Claims (10)

[Claims] An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, comprising: a radiation image area recognizing means for recognizing a radiation image area from an image including the radiation image area; An image processing apparatus for outputting an area other than the radiation image area recognized by the radiation image area recognition means at a predetermined density. 2. An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, comprising: a radiation image area recognizing means for recognizing a radiation image area from an image including the radiation image area; And an outside radiation image area trimming means for trimming and outputting an area other than the radiation image area recognized by the radiation image area recognition means. 3. An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, comprising: a radiation image area recognizing means for recognizing a radiation image area from an image including the radiation image area; A predetermined density output unit outside the radiation image area for outputting an area other than the radiation image area recognized by the radiation image area recognition means at a predetermined density; and an area other than the radiation image area recognized by the radiation image area recognition means. A radiographic image area trimming means for trimming and outputting, and whether the radiographic image area is output at a predetermined density by the radiographic image area predetermined density output means or a trimming output by the radiographic image area trimming means. An image processing apparatus, comprising: an output method selection unit capable of selecting an output method. 4. An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, wherein a threshold value is set for setting a threshold value of a pixel of the image including the radiation image area. Means for outputting a pixel having a lower density than a threshold set by the threshold setting means at a predetermined density. 5. An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, wherein a threshold value is set for a pixel of the image including the radiation image area. An image processing apparatus comprising: means for trimming a pixel lower than a threshold value set by the threshold value setting means; 6. An image processing apparatus for processing an image including a radiation image area generated by radiation passing through a subject, comprising: a threshold setting unit for setting a threshold value of a pixel of the image including the radiation image area. Means for outputting a pixel having a lower density than a threshold value set by the threshold value setting means at a predetermined density; a pixel having a predetermined density or less; Below-threshold pixel trimming means for trimming and outputting low pixels, and whether to output at low luminance by the below-threshold pixel predetermined density output means or to output by trimming by the below-threshold pixel trimming means An image processing apparatus, comprising: an output method selection unit capable of selecting an output method. 7. The radiographic image area recognizing means for recognizing a radiographic image area, wherein the threshold value setting means determines based on a minimum value in the radiographic image area recognized by the radiographic image area recognizing means. 5. The method according to claim 4, wherein
The image processing apparatus according to claim 6. 8. A radiation image area recognizing means for recognizing a radiation image area, and a cumulative histogram producing means for producing a cumulative histogram in the radiation image area recognized by the radiation image area recognizing means. 7. The image processing apparatus according to claim 4, wherein the image data is determined by a predetermined ratio determined from the cumulative histogram created by the cumulative histogram creating unit. 9. The image processing apparatus according to claim 4, further comprising a threshold value changing unit for changing a threshold value determined by said threshold value setting unit. apparatus. 10. The image processing apparatus according to claim 1, further comprising a radiation image acquiring unit for acquiring an image including a radiation image area generated by radiation passing through a subject. Medical image processing device.