WO2012132323A1

WO2012132323A1 - Method and device for imaging radiological image of breast

Info

Publication number: WO2012132323A1
Application number: PCT/JP2012/001926
Authority: WO
Inventors: 孝夫桑原; 大田　恭義; 靖子八尋; 玲長谷川
Original assignee: 富士フイルム株式会社
Priority date: 2011-03-28
Filing date: 2012-03-21
Publication date: 2012-10-04

Abstract

[Problem] To precisely detect pathological changes such as tumours which become visible due to the insertion of a contrast medium into a breast. [Solution] Compress, by means of compression plates, a breast into which a contrast medium has been inserted, irradiate radiation from different imaging directions on the compressed breast into which the contrast medium has been inserted, and use a radiological image detector to detect the radiation which, due to said irradiation, has penetrated the breast into which the contrast medium has been inserted, and acquire a radiological image of the breast into which the contrast medium has been inserted for each imaging direction in which detection has been carried out.

Description

Breast radiation imaging method and apparatus

The present invention relates to a breast radiographic imaging method and apparatus for acquiring a plurality of breast radiographic images by irradiating the breast with radiation from different directions, in particular, specifying a position of a lesion or the like in a breast radiographic image, It is used in a stereo biopsy device that collects a tissue piece at that position.

In a hospital examination, a tissue piece around a lesion may be collected. Recently, as a method of collecting a tissue piece without imposing a heavy burden on a patient, a hollow tissue collecting needle (hereinafter referred to as a biopsy needle) is used. A biopsy that attracts the patient and collects the tissue embedded in the needle cavity has attracted attention. A stereo biopsy device has been proposed as a device for performing such a biopsy.

This stereo biopsy device irradiates a subject with radiation from mutually different directions to acquire a plurality of radiation images, identifies a three-dimensional position of a lesion based on these radiation images, and By controlling the tip to reach the specific position, the tissue piece can be collected from a desired position.

As one of the stereo biopsy devices as described above, Patent Document 1 proposes a device for collecting a diseased tissue in the breast. In Patent Document 1, in order to detect and collect a lesion in which blood vessels such as a tumor that does not clearly appear on a normal radiographic image are concentrated rather than a lesion that clearly appears on a radiographic image such as microcalcifications. In addition, a method has been proposed in which a contrast medium is injected into the breast and a radiographic image is taken. More specifically, in Patent Document 1, after compressing the breast, first, an initial image before contrast medium injection is taken, and then a contrast medium injection image is taken by introducing the contrast medium into the breast. There has been proposed a method of obtaining an image in which a tumor in which a contrast agent is concentrated appears clearly by subtracting an initial image from an input image.

JP 2002-360556 A

However, as in Patent Document 1, if the contrast medium is injected after the breast is compressed, there is a problem that the contrast medium does not easily diffuse through the blood vessels in the breast due to the compression and the contrast medium does not reach the tumor.

In view of the circumstances described above, an object of the present invention is to provide a breast radiographic imaging method and apparatus capable of clearly detecting a lesion such as a tumor that appears when a contrast medium is introduced.

In the breast radiographic imaging method of the present invention, the breast after injection of the contrast agent is compressed by a compression plate, radiation is applied to the compressed breast after injection of the contrast agent from different imaging directions, and imaging is performed by the irradiation. Radiation that has passed through the breast after injection of the agent is detected by a radiation image detector, and a breast radiation image after injection of the contrast agent for each detected imaging direction is acquired.

In the above-described breast image capturing method of the present invention, a plurality of breasts detected by a radiation image detector by performing a plurality of times of radiation irradiation with different energy distributions in each photographing direction. A radiographic image can be acquired, and a subtraction image can be acquired for each imaging direction by performing subtraction processing on the plurality of breast radiographic images.

The radiographic imaging apparatus of the present invention includes a compression plate that is controlled so as to compress the breast after the contrast agent is injected into the breast, and a contrast agent that is compressed by the compression plate. A radiation irradiating unit that irradiates radiation from different breasts to the breast, a radiation image detector that detects radiation that has been irradiated by the radiation irradiating unit and passed through the breast after the contrast medium is injected, and a radiation image detector And a radiographic image acquisition unit that acquires a breast radiographic image after the contrast medium is introduced for each detected imaging direction.

Further, the radiation irradiating unit is configured to irradiate a plurality of times of radiations having different energy distributions in each imaging direction, and the radiation image acquiring unit is configured to perform a plurality of detections by the radiation image detector by the plurality of times of radiation irradiation. It is assumed that a breast radiation image is acquired, and a subtraction image acquisition unit that performs subtraction processing on a plurality of breast radiation images acquired by the radiation image acquisition unit and acquires subtraction images for each imaging direction can be provided.

Also, a display unit that displays the subtraction image in each shooting direction as a stereoscopic image can be provided.

In addition, a calcification extraction image acquisition unit that obtains a calcification extraction image by performing calcification extraction processing on the breast radiation image for each imaging direction acquired by the radiological image acquisition unit, a subtraction image and lime for each imaging direction A composite image generation unit that generates a composite image by superimposing the computerized extracted image can be provided.

In addition, after the radiation irradiating unit irradiates a plurality of different radiations in the first imaging direction, the radiation irradiating unit performs a plurality of different radiations in a second imaging direction different from the first imaging direction. I can do it.

Also, it is possible to provide a low-resolution processing unit that performs a process of lowering the resolution on the breast radiographic image after the contrast agent is acquired acquired by the radiological image acquiring unit.

Also, it is possible to provide an instruction receiving unit that receives instruction information as to whether or not to perform resolution reduction processing.

In addition, the instruction information for performing the process for reducing the resolution is information indicating that the contrast medium has been applied to the breast, and the instruction information for not performing the process for reducing the resolution is not applied to the breast. It can be information indicating this.

In addition, when the process of lowering the resolution is performed on the radiation irradiation unit, the dose of radiation can be reduced as compared with the case of not performing the process of reducing the resolution.

Also, a readout control unit can be provided which controls to perform binning readout when reading out a breast radiation image after the contrast medium is fed from the radiation image detector.

Also, it is possible to provide an instruction receiving unit that receives instruction information on whether to perform binning reading.

Further, the instruction information for performing binning readout is information indicating that the contrast medium has been input to the breast, and the instruction information for not performing binning readout is information indicating that the contrast medium has not been input to the breast. It can be.

In addition, when the binning readout is performed for the radiation irradiation unit, the radiation dose can be reduced as compared with the case where the binning readout is not performed.

Also, a biopsy needle unit having a biopsy needle inserted into the breast can be provided.

According to the breast radiographic imaging method and apparatus of the present invention, the breast after injection of the contrast agent is compressed by the compression plate, and the compressed breast after injection of the contrast agent is irradiated with radiation from mutually different imaging directions, The radiation that has passed through the breast after injection of the contrast agent is detected by the radiation image detector by the irradiation, and the breast radiation image after injection of the contrast agent for each detected imaging direction is acquired. Can be sufficiently diffused, and a breast radiation image in which a lesion such as a tumor appears clearly can be acquired.

Further, in the breast image capturing method and apparatus of the present invention described above, a plurality of times of irradiation with different energy distributions in each imaging direction are performed, and a plurality of radiation images detected by the radiation image detector by the plurality of times of radiation irradiation. When a breast radiation image is acquired and subtraction processing is performed on each of the plurality of breast radiation images to acquire a subtraction image for each imaging direction, images such as mammary glands in the vicinity of the tumor are removed by subtraction processing. Therefore, the shape and size of the tumor can be grasped more clearly.

Also, when the subtraction image in each photographing direction is displayed as a stereoscopic image, the three-dimensional position of the tumor in the breast can be grasped more clearly.

In addition, a calcification extraction process is performed on a breast radiation image for each imaging direction to obtain a calcification extraction image, and a composite image is generated by superimposing the subtraction image and the calcification extraction image for each imaging direction. In this case, the distance between the microcalcification and the tumor can be grasped, and for example, the insertion direction of the biopsy needle at the time of biopsy can be set more appropriately.

In addition, as described above, when a plurality of irradiations with different energy distributions are performed, a second irradiation different from the first imaging direction is performed after performing a plurality of irradiations with different radiations in the first imaging direction. If a plurality of different irradiations are performed in the imaging direction, the moving distance of the radiation source can be minimized, so that the imaging time can be reduced and the imaging efficiency can be improved. In addition, the burden on the subject can be reduced.

In addition, when the processing for reducing the resolution is performed on the breast radiation image after the contrast agent is introduced, or when the binning readout is performed at the time of readout of the breast radiation image, the pixel signal can be increased. Accordingly, the radiation dose at the time of imaging can be reduced, and the exposure dose of the subject can be reduced.

1 is a schematic configuration diagram of a breast image photographing display system using an embodiment of a breast radiation image photographing apparatus of the present invention. The figure which looked at the arm part of the mammography display system shown in FIG. 1 from the right direction of FIG. The figure which looked at the imaging stand of the breast image radiographing display system shown in Drawing 1 from the upper part 1 is a block diagram showing a schematic configuration inside a computer of the breast image capturing and displaying system shown in FIG. The flowchart figure for demonstrating the effect | action of the mammography imaging display system using one Embodiment of the mammography apparatus of this invention. Block diagram of a mammography display system using another embodiment of the mammography apparatus of the present invention Block diagram of a mammography display system using another embodiment of the mammography apparatus of the present invention

Hereinafter, a breast image radiographing display system using an embodiment of the breast radiographic image radiographing apparatus of the present invention will be described with reference to the drawings. The breast image radiographing display system of this embodiment is a system that also operates as a stereo biopsy device for breasts by attaching a detachable biopsy unit. First, a schematic configuration of the entire breast image capturing and displaying system according to the present embodiment will be described. FIG. 1 is a diagram showing a schematic configuration of a mammography display system with a biopsy unit attached.

As shown in FIG. 1, a breast image radiographing display system 1 according to this embodiment includes a mammography apparatus 10, a computer 3 connected to the mammography apparatus 10, and a monitor 4 (display unit) connected to the computer 3. And an input unit 5.

As shown in FIG. 1, the mammography apparatus 10 includes a base 11, a rotary shaft 12 that can move in the vertical direction (Z direction) with respect to the base 11, and can rotate. The arm part 13 connected with the base 11 is provided. FIG. 2 shows the arm portion 13 viewed from the right direction in FIG.

The arm section 13 has an alphabet C shape, and a radiation table 16 is attached to one end of the arm section 13 so as to face the imaging table 14 at the other end. The rotation and vertical movement of the arm unit 13 are controlled by an arm controller 31 incorporated in the base 11.

Inside the imaging table 14 are provided a radiation image detector 15 such as a flat panel detector and a detector controller 33 that controls reading of a charge signal from the radiation image detector 15. Further, inside the imaging table 14, a charge amplifier that converts the charge signal read from the radiation image detector 15 into a voltage signal, a correlated double sampling circuit that samples the voltage signal output from the charge amplifier, A circuit board provided with an AD conversion unit for converting a voltage signal into a digital signal is also installed.

In addition, the photographing table 14 is configured to be rotatable with respect to the arm unit 13, and even when the arm unit 13 rotates with respect to the base 11, the direction of the photographing table 14 is fixed to the base 11. can do.

The radiation image detector 15 can repeatedly perform recording and reading of a radiation image, and may use a so-called direct type radiation image detector that directly receives radiation and generates charges. Alternatively, a so-called indirect radiation image detector that converts radiation once into visible light and converts the visible light into a charge signal may be used. As a radiation image signal readout method, a radiation image signal is read out by turning on / off a TFT (thin film transistor) switch, or by irradiating reading light. A so-called optical readout system from which a radiation image signal is read out can be used. Further, as an indirect radiation image detector, a device using a CMOS (Complementary Metal Oxide Semiconductor) sensor or a device using a CCD (Charge Coupled Device Device Image Sensor) may be used.

A radiation source 17 and a radiation source controller 32 are housed in the radiation irradiation unit 16. The radiation source 17 includes an X-ray tube and an X-ray high voltage generator that applies a tube voltage to the X-ray tube. The radiation irradiating unit 16 can continuously irradiate X-rays having different energy distributions a plurality of times under the control of the radiation source controller 32 in order to perform energy subtraction imaging.

Here, X-rays with different energy distributions can be generated by changing the tube voltage for each exposure to change the maximum value, peak value, average value, etc. on the X-ray spectral distribution. Alternatively, X-rays may be generated with the same energy distribution, and may be generated by passing through filters having different characteristics for each exposure. Further, the X-ray dose may be changed by changing the tube current or the exposure time for each exposure.

The radiation source controller 32 controls the X-ray exposure timing, tube voltage, tube current, exposure time, number of exposures, etc. from the radiation source 17.

Further, in the central portion of the arm portion 13, a compression plate 18 disposed above the imaging table 14 to press and compress the breast, a support portion 20 that supports the compression plate 18, and a support portion 20 in the vertical direction ( A moving mechanism 19 for moving in the Z direction) is provided. The position of the compression plate 18 and the compression pressure are controlled by the compression plate controller 34. FIG. 3 is a view of the compression plate 18 shown in FIG. 1 as viewed from above. As shown in the drawing, the compression plate 18 has a biopsy in a state where the breast is fixed by the imaging table 14 and the compression plate 18. An opening 6 of a predetermined size is provided so that it can be performed.

The biopsis unit 2 is mechanically and electrically connected to the mammography display system 1 by inserting the base portion of the biopsy unit 2 into the opening of the support portion 20 of the compression plate 18 and attaching the lower end of the base portion to the arm portion 13. To be connected.

The biopsy unit 2 includes a biopsy needle 21 that is punctured into the breast. The biopsy needle unit 22 is configured to be detachable, a needle support portion 23 that supports the biopsy needle unit 22, and the needle support portion 23 as a rail. And a moving mechanism 24 that moves the biopsy needle unit 22 in the X, Y, and Z directions shown in FIGS. 1 to 3 by moving the needle support part 23 in and out. The position of the tip of the biopsy needle 21 of the biopsy needle unit 22 is recognized and controlled as position coordinates (x, y, z) in a three-dimensional space by a needle position controller 35 provided in the moving mechanism 24. 1 is the X direction, the paper vertical direction in FIG. 2 is the Y direction, and the paper vertical direction in FIG. 3 is the Z direction.

The computer 3 includes a central processing unit (CPU) and a storage device such as a semiconductor memory, a hard disk, and an SSD. The radiographic image acquisition unit 40, the control unit 41, and the subtraction shown in FIG. An image acquisition unit 42 is configured.

The radiation image acquisition unit 40 acquires and stores a radiation image signal for each imaging angle detected by the radiation image detector 15.

The subtraction image acquisition unit 42 performs subtraction processing on a plurality of breast radiographic images acquired by the radiographic image acquisition unit 40 by multiple times of X-ray irradiation with different energy distributions as described above, and acquires subtraction images. To do. The subtraction process is a differential signal that represents an image of a specific structure by associating each pixel of a plurality of breast radiation images, multiplying the plurality of breast radiation images by a predetermined weighting coefficient, and performing a subtraction process. It is a process to acquire.

In this embodiment, since the main purpose is to detect a mass appearing on a breast radiographic image by injection of a contrast medium into the breast, the subtraction image acquisition unit 42 stores the range of the mass appearing by this contrast medium. A weighting coefficient that enhances contrast is set in advance.

In this embodiment, the arm unit 13 is rotated to capture breast radiation images from a plurality of imaging directions. The subtraction image acquisition unit 42 acquires a plurality of breasts acquired for each imaging direction. A subtraction image for each photographing direction is acquired based on the radiation image.

The control unit 41 outputs predetermined control signals to the various controllers 31 to 35 to control the entire system, and displays the subtraction image acquired by the subtraction image acquisition unit 42 on the monitor 4 as a two-dimensional image. Or displayed on the monitor 4 as a stereo image. A specific control method will be described in detail later.

The monitor 4 can display a stereo image by using two subtraction images taken from two different shooting directions, and can also display a subtraction image taken from each shooting direction as a two-dimensional image. It is configured. As will be described in detail later, the monitor 4 of the present embodiment displays two subtraction images taken from ± 2 ° photographing directions as stereo images, and the subtraction taken from 0 ° and ± 15 ° photographing directions. Each image is displayed as a two-dimensional image.

As a configuration for displaying a stereo image, for example, a radiographic image based on two radiographic image signals is displayed using two screens, and one of the radiographic images is observed by using a half mirror or a polarizing glass. It is possible to adopt a configuration in which a stereo image is displayed by being incident on the right eye of the observer and the other radiation image is incident on the left eye of the observer. Or, for example, two radiographic images may be displayed in a superimposed manner while being shifted by a predetermined amount of parallax, and this may be configured to generate a stereo image by observing with a polarizing glass, or a parallax barrier method and a lenticular method As described above, a stereo image may be generated by displaying two radiation images on a stereoscopically viewable 3D liquid crystal.

Further, the device that displays a stereo image and the device that displays a two-dimensional image may be configured separately, or may be configured as the same device if they can be displayed on the same screen.

The input unit 5 is configured by a pointing device such as a keyboard or a mouse, for example, and is configured so that the position of a tumor or the like in a subtraction image displayed as a two-dimensional image on the monitor 4 can be specified. . The input unit 5 receives an input of shooting conditions and an operation instruction by the photographer.

Next, the operation of the breast image radiographing display system of this embodiment will be described with reference to the flowchart shown in FIG.

First, a contrast agent for detecting a tumor is introduced into the breast M of the subject (S10). After that, the breast M after the contrast medium is introduced is placed on the imaging table 14 (S12), and then the breast M after the contrast medium is introduced by the compression plate 18 in response to a predetermined instruction input from the input unit 5. It is compressed by a predetermined pressure (S14).

In the input unit 5, after various shooting conditions are input by the photographer, an instruction to start shooting is input. At this time, it is assumed that the biopsy needle unit 22 is retracted upward and has not yet been punctured into the breast.

When there is an instruction to start shooting in the input unit 5, in the present embodiment, scout shooting, stereo shooting for acquiring a biopsy targeting image, and stereo shooting for acquiring a stereo image display image are performed. First, scout shooting is performed out of these shooting (S16).

Specifically, the control unit 41 reads out a preset shooting angle θ = 0 °, and outputs the read shooting angle to the arm controller 31.

The arm controller 31 outputs a control signal so that the arm unit 13 is in a direction perpendicular to the imaging table 14 based on the input imaging angle θ = 0 °.

Then, according to the control signal output from the arm controller 31, the arm unit 13 is disposed at a position of θ = 0 °, and then the control unit 41 controls the radiation source controller 32 to emit radiation. Is output.

The radiation source controller 32 outputs a control signal to the radiation source 17 so that X-rays having different energy distributions are continuously exposed twice according to the input control signal. The radiation source 17 first performs the first X-ray exposure according to the input control signal. In the present embodiment, the X-ray energy distribution is changed by changing the tube voltage applied to the X-ray tube of the radiation source 17, and the second X-ray exposure is performed in the first X-ray exposure. It is assumed that a tube voltage relatively higher than that of X-ray exposure is applied to the X-ray tube.

The X-rays exposed from the radiation source 17 are transmitted through the breast M after the contrast agent is introduced and irradiated to the radiation image detector 15, and the radiation image detector 15 detects a breast radiation image. The breast radiation image detected at this time is referred to as a high-pressure breast radiation image.

Subsequently, a control signal is output from the control unit 41 to the detector controller 33, and the detector controller 33 reads out the high-pressure breast radiation image detected by the radiation image detector 15 according to the input control signal and reads the read-out image. After performing the predetermined signal processing on the outputted high-pressure breast radiographic image, it is output to the radiographic image acquisition unit 40 of the computer 3.

The radiological image acquisition unit 40 acquires and stores the high-pressure breast radiographic image output from the detector controller 33.

Next, the radiation source 17 performs the second X-ray exposure according to the control signal output from the radiation source controller 32. In the second X-ray exposure, a lower tube voltage is applied to the X-ray tube than in the first X-ray exposure.

The X-rays exposed from the radiation source 17 are transmitted through the breast M after the contrast agent is introduced and irradiated to the radiation image detector 15, and the radiation image detector 15 detects a breast radiation image. The breast radiation image detected at this time is referred to as a low-pressure breast radiation image.

Subsequently, a control signal is output from the control unit 41 to the detector controller 33, and the detector controller 33 reads out the low-pressure breast radiation image detected by the radiation image detector 15 in accordance with the input control signal and reads the read-out image. A predetermined signal processing is performed on the outputted low-pressure breast radiographic image, and then output to the radiographic image acquisition unit 40 of the computer 3.

The radiological image acquisition unit 40 acquires and stores the low-pressure breast radiographic image output from the detector controller 33.

Next, after scout shooting as described above, shooting in one shooting direction of stereo shooting for acquiring the targeting image is performed (S18). Specifically, in the present embodiment, θ = ± 15 ° is set in advance as the shooting angle of stereo shooting for acquiring the targeting image, and the control unit 41 sets the two shooting angles. First, the shooting angle θ = + 15 ° is read, and the read shooting angle is output to the arm controller 31. In the present embodiment, the shooting angle of stereo shooting for acquiring the targeting image is set to θ = ± 15 °. However, the present invention is not limited to this, and other shooting angles may be used.

The arm controller 31 outputs a control signal so that the arm unit 13 rotates + 15 ° with respect to a direction perpendicular to the imaging table 14 based on the input imaging angle θ = + 15 °.

Then, after the arm unit 13 is disposed at the position of θ = + 15 ° according to the control signal output from the arm controller 31, the control unit 41 performs the same operation on the radiation source controller 32 as in the scout imaging described above. A control signal is output so as to perform two X-ray exposures, and control is performed to read out a breast radiation image detected by the radiation image detector 15 for each X-ray exposure to the detector controller 33. Output a signal.

Then, in accordance with the control signal from the control unit 41, two times of X-ray exposure and breast radiation image reading are performed in the same manner as the above-described scout imaging, and the radiographic image acquisition unit 40 performs an imaging angle θ. Acquire a high-pressure breast radiation image and a low-pressure breast radiation image for + 15 °.

Next, after shooting at the shooting angle θ = + 15 ° as described above, shooting in one shooting direction of stereo shooting for acquiring a stereo image display image is performed (S20). Specifically, in the present embodiment, θ = ± 2 ° is set in advance as a shooting angle of stereo shooting for acquiring an image for displaying a stereo image, and the control unit 41 controls the two shootings. Of the angles, first, the shooting angle θ = + 2 ° is read, and the read shooting angle is output to the arm controller 31. In the present embodiment, the shooting angle of stereo shooting for acquiring a stereo image display image is set to θ = ± 2 °. However, the present invention is not limited to this, and other shooting angles may be used.

The arm controller 31 outputs a control signal so that the arm unit 13 rotates + 2 ° with respect to a direction perpendicular to the imaging table 14 based on the input imaging angle θ = + 2 °.

Then, after the arm unit 13 is arranged at the imaging angle θ = + 2 ° in accordance with the control signal output from the arm controller 31, the control unit 41 sends the radiation source controller 32 to the radiation source controller 32 in the same manner as the scout imaging described above. On the other hand, a control signal is output so as to perform two X-ray exposures, and a breast radiation image detected by the radiation image detector 15 is read out to the detector controller 33 for each X-ray exposure. Output a control signal.

Then, in accordance with the control signal from the control unit 41, two times of X-ray exposure and breast radiation image reading are performed in the same manner as the above-described scout imaging, and the radiographic image acquisition unit 40 performs an imaging angle θ. Acquire a high-pressure breast radiation image and a low-pressure breast radiation image for + 2 °.

Next, after shooting at the shooting angle θ = + 2 ° as described above, shooting in the other shooting direction of the stereo shooting for obtaining an image for displaying a stereo image is performed (S22). Specifically, the control unit 41 reads the shooting angle θ = −2 ° and outputs the read shooting angle to the arm controller 31.

The arm controller 31 outputs a control signal so that the arm unit 13 is rotated by −2 ° with respect to a direction perpendicular to the imaging table 14 based on the input imaging angle θ = −2 °.

Then, after the arm unit 13 is arranged at a position of θ = −2 ° in accordance with the control signal output from the arm controller 31, the control unit 41 performs the same operation as the above-described scout imaging with respect to the radiation source controller 32. A control signal is output so as to perform two X-ray exposures, and a breast radiation image detected by the radiation image detector 15 is read out to the detector controller 33 for each X-ray exposure. Output a control signal.

Then, in accordance with the control signal from the control unit 41, two times of X-ray exposure and breast radiation image reading are performed in the same manner as the above-described scout imaging, and the radiographic image acquisition unit 40 performs an imaging angle θ. Acquire a high-pressure breast radiation image and a low-pressure breast radiation image for -2 °.

Next, after shooting at the shooting angle θ = −2 ° as described above, shooting in the other shooting direction of stereo shooting for acquiring the targeting image is performed again (S24). Specifically, the control unit 41 reads the shooting angle θ = −15 ° and outputs the read shooting angle to the arm controller 31.

The arm controller 31 outputs a control signal so that the arm unit 13 is rotated by −15 ° with respect to the direction perpendicular to the imaging table 14 based on the input imaging angle θ = −15 °.

Then, after the arm unit 13 is disposed at a position of θ = −15 ° in accordance with the control signal output from the arm controller 31, the control unit 41 controls the radiation source controller 32 in the same manner as the scout imaging described above. A control signal is output so as to perform two X-ray exposures, and a breast radiation image detected by the radiation image detector 15 is read out to the detector controller 33 for each X-ray exposure. Output a control signal.

Then, in accordance with the control signal from the control unit 41, two times of X-ray exposure and breast radiation image reading are performed in the same manner as the above-described scout imaging, and the radiographic image acquisition unit 40 performs an imaging angle θ. Acquire a high-pressure breast radiation image and a low-pressure breast radiation image for -15 °.

As described above, scout imaging with an imaging angle θ = 0 °, stereo imaging with an imaging angle θ = ± 15 °, and stereo imaging with an imaging angle θ = ± 2 ° are performed, and the radiation image acquisition unit 40 performs each imaging. Acquire a high-pressure breast radiation image and a low-pressure breast radiation image for the angle.

Then, the radiation image acquisition unit 40 outputs the high-pressure breast radiation image and the low-pressure breast radiation image acquired for each imaging angle to the subtraction image acquisition unit 42.

The subtraction image acquisition unit 42 performs subtraction processing using the input high-pressure breast radiation image and low-pressure breast radiation image for each imaging angle, and acquires a subtraction image for each imaging angle (S26).

Then, the control unit 41 has two subtractions, that is, the subtraction image of the scout shooting (shooting angle θ = 0 °) acquired by the subtraction image acquisition unit 42 and the stereo shooting of the targeting image (shooting angle θ = ± 15 °). The image is displayed on the monitor 4 as a two-dimensional image, and a stereoscopically viewable stereo image is displayed on the monitor 4 using two subtraction images of a stereo image display image (photographing angle θ = ± 2 °). (S28).

Next, after the subtraction image of scout photography, the subtraction image for targeting, and the stereo image are displayed as described above, a mass in the breast is found by the observer, and the observer subsequently uses the biopsy unit 2 to extract the tissue. If it is desired to collect the target, first, a target such as a tumor is designated by the observer on the two subtraction images for targeting displayed on the monitor 4 (S30). The target may be specified by, for example, specifying the target position using a cursor with a pointing device such as a mouse in the input unit 5.

Then, the position information (x1, y1) and (x2, y2) of the targets on the two targeting subtraction images designated by the observer are acquired by the control unit 41. The control unit 41 is based on the position information (x1, y1), (x2, y2), the imaging angle θ = ± 15 °, and the distance between the focal point of the radiation source 17 and the detection surface of the radiation image detector 15. Then, the three-dimensional position information (x3, y3, z3) of the target in the breast is calculated. Note that the position information in the y direction is y1 = y2 = y3. The position information x3 in the x direction and the position information z3 in the y direction are calculated using, for example, a triangulation method.

Then, the control unit 41 outputs the calculated three-dimensional position information (x3, y3, z3) of the target to the needle position controller 35 of the biopsy unit 2.

In this state, when a predetermined operation button is pressed in the input unit 5, a control signal for moving the biopsy needle 21 is output from the control unit 41 to the needle position controller 35. Based on the value of the position information (x3, y3, z3) input previously, the needle position controller 35 is arranged so that the tip of the biopsy needle 21 is located at the position indicated by the coordinates (x3, y3, z3 + α). The biopsy needle 21 is moved. Here, α is set to a sufficiently large value so that the biopsy needle 21 does not pierce the breast. Thereby, the biopsy needle 21 is set above the target.

Thereafter, when a predetermined operation for instructing the biopsy needle 21 to be punctured by the observer is performed in the input unit 5, the tip of the biopsy needle 21 is coordinated (x3, x) under the control of the control unit 41 and the needle position controller 35. The biopsy needle 21 is moved so as to be arranged at the position indicated by y3, z3), and puncture of the breast by the biopsy needle 21 is performed (S32).

According to the breast image radiographing display system of the above embodiment, the breast after the contrast medium is injected is compressed by the compression plate 18, and the compressed breast after the contrast medium is injected is irradiated with X-rays from different imaging directions. Since the X-ray transmitted through the breast after injection of the contrast agent by the irradiation is detected by the radiological image detector 15 and the breast radiographic image after injection of the contrast agent for each detected imaging direction is acquired, The contrast medium can be sufficiently diffused to obtain a breast radiation image in which a lesion such as a tumor appears clearly.

In addition, since a subtraction process is performed on a plurality of breast radiation images acquired at each imaging angle to acquire a subtraction image for each imaging direction, images such as mammary glands in the vicinity of the tumor can be removed by the subtraction process. It is possible to grasp the shape and size of the tumor more clearly.

In addition, since the subtraction image in each photographing direction is displayed as a stereoscopically viewable stereo image, the three-dimensional position of the tumor in the breast can be grasped more clearly.

In the above embodiment, target position information is specified on two targeting subtraction images (shooting angle θ = ± 15 °). Based on the specified position information, stereo image display is performed. The target position information on the two subtraction images (shooting angle θ = ± 2 °) may be calculated, and the target position may be displayed on the two subtraction images displayed as stereo images. Thereby, the observer can confirm whether or not the same target position is designated on the two subtraction images for targeting (shooting angle θ = ± 15 °).

In the above embodiment, the target position is specified on the two subtraction images for targeting (shooting angle θ = ± 15 °) displayed as a two-dimensional image. Alternatively, the target position may be specified using a stereoscopic cursor or the like on a stereo image displayed so as to be stereoscopically viewable using two subtraction images (photographing angle θ = ± 4 °) for stereo image display. When the target position is designated on the stereo image in this way, the target position is set on the two subtraction images for targeting displayed as the two-dimensional image based on the designated three-dimensional position information. It may be displayed so that the observer can confirm it.

Further, in the above embodiment, an image capable of mainly observing a tumor is displayed by capturing a breast after contrast medium injection and acquiring a subtraction image, but when a subtraction image is acquired in this way The calcification of the breast disappears by the subtraction process and cannot be observed. As described above, when a mass is collected by biopsy, it may be desired to know the distance between the mass and calcification, and it may be preferable that calcification is displayed. Therefore, a composite image may be generated by superimposing the above-described subtraction image and the calcification extraction image obtained by extracting calcification, and the composite image may be displayed.

Specifically, as shown in FIG. 6, the computer 3 may be provided with a calcification extraction image acquisition unit 43 and a composite image acquisition unit 44.

The calcification extraction image acquisition unit 43 performs calcification extraction processing for each imaging angle by performing calcification extraction processing on the high-pressure breast radiation image or low-pressure breast radiation image for each imaging angle acquired by the radiation image acquisition unit 40. Get an image. As the calcification extraction process, a process for extracting based on the characteristics of the concentration distribution and morphological characteristics of the calcification may be used. Specifically, a morphology filter process suitable for detecting a microcalcification shadow, etc. Can be used.

And the calcification extraction image for every photographing angle acquired in the calcification extraction image acquisition part 43 is output to the synthetic | combination image acquisition part 44. FIG.

The composite image acquisition unit 44 superimposes the input calcification extraction image and the subtraction image for each shooting angle acquired by the subtraction image acquisition unit 42 to generate a composite image for each shooting angle.

Then, based on the composite image for each shooting angle acquired by the composite image acquisition unit 44, the control unit 41 converts the composite image for scout shooting and the composite image for stereo shooting for targeting into two dimensions, as in the above embodiment. In addition to being displayed as an image, a stereo image composite image for displaying a stereo image is displayed as a stereoscopically viewable stereo image.

Note that the above-described composite image and subtraction image may be displayed simultaneously, or the composite image and subtraction image may be switched and displayed.

In addition, as in the above-described embodiment, when the breast after imaging the contrast medium is photographed and a subtraction image is acquired and an image capable of observing the tumor is displayed, the resolution is much higher than when calcification is mainly observed. Is not necessary. Therefore, binning processing may be performed on the high-pressure breast radiation image and the low-pressure breast radiation image for each imaging angle acquired by the radiation image acquisition unit 40 to obtain a low-resolution image.

Specifically, as shown in FIG. 7, a binning processing unit 45 is provided, and binning processing is performed on the high-pressure breast radiation image and the low-pressure breast radiation image for each imaging angle acquired by the radiation image acquisition unit 40. That's fine. The binning process here refers to a process of adding signals of a plurality of pixels to obtain a signal of one pixel.

Then, for example, in the input unit 5 (corresponding to the instruction receiving unit), an input of information indicating whether the breast is taken after the contrast medium is introduced or whether the breast is taken without the contrast agent is received, In response to the input, binning processing may be performed in the case of imaging of the breast after the contrast medium has been input, and binning processing may be disabled in the case of imaging of the breast in which no contrast medium is input. That is, information indicating that breast imaging after contrast medium injection is instruction information for performing binning processing, and information indicating that breast imaging without contrast medium injection is instruction information for performing no binning processing. .

In the above description, the binning process is performed by image processing. However, the binning method is not limited to this, and for example, the detector controller 33 (corresponding to the read control unit) receives a high voltage from the radiation image detector 15. When reading out the breast radiation image and the low-pressure breast radiation image, binning readout may be performed in which a plurality of pixels are read out together, and added to output.

Also in this case, for example, the input unit 5 accepts an input of information indicating whether the imaging of the breast after the contrast medium is input or whether the imaging of the breast is not applied with the contrast medium, and the contrast medium is received according to the input. Binning readout may be performed when photographing the breast after injection, and binning readout may not be performed when photographing the breast without introducing the contrast agent.

In addition, as described above, when performing binning processing or binning readout of a high-pressure breast radiation image and a low-pressure breast radiation image, signals of a plurality of pixels are added, so that the X-ray dose is reduced when photographing these breast radiation images. be able to.

Therefore, when binning a high-pressure breast radiation image and a low-pressure breast radiation image, the dose of X-rays exposed from the radiation source 17 by the radiation source controller 32 may be lowered. In the above embodiment, However, the present invention is not limited to this. For example, a contrast medium injection device controlled by the computer 3 is provided, and the contrast medium injection device supplies the contrast medium to the breast. You may do it. In this case, the compression of the breast may be performed by starting the movement of the compression plate 18 in accordance with a signal indicating that the injection of the contrast medium into the breast by the contrast medium injector is completed.

Claims

The breast after injection of contrast agent is compressed with a compression plate,
Irradiating the compressed breast with the contrast medium applied from different imaging directions,
A radiation image detector detects radiation that has passed through the breast after injection of the contrast agent by the irradiation,
A breast radiographic imaging method, comprising: acquiring a breast radiographic image after the contrast medium is introduced for each of the detected imaging directions.
Irradiating a plurality of times with different energy distributions in each imaging direction,
Obtaining a plurality of breast radiation images detected by the radiation image detector by the irradiation of the plurality of times;
The breast radiographic image capturing method according to claim 1, wherein a subtraction process is performed on the plurality of breast radiographic images to obtain a subtraction image for each imaging direction.
A compression plate that is controlled to compress the breast after the contrast agent has been injected into the breast;
A radiation irradiating unit that irradiates radiation from mutually different imaging directions with respect to the breast after injection of the contrast medium pressed by the compression plate;
A radiation image detector for detecting radiation irradiated by the radiation irradiation unit and transmitted through the breast after the contrast medium is introduced;
A breast radiographic image capturing apparatus, comprising: a radiological image acquisition unit that acquires a breast radiographic image after injection of the contrast medium for each of the imaging directions detected by the radiographic image detector.
The radiation irradiating unit irradiates a plurality of times with different energy distributions in each imaging direction,
The radiological image acquisition unit acquires a plurality of breast radiographic images detected by the radiological image detector by the irradiation of the plurality of times of radiation,
The breast according to claim 3, further comprising a subtraction image acquisition unit that performs subtraction processing on a plurality of breast radiographic images acquired by the radiological image acquisition unit to acquire subtraction images for each of the imaging directions. Radiation imaging device.
5. The breast radiographic image capturing apparatus according to claim 4, further comprising a display unit that displays the subtraction image in each imaging direction as a stereoscopic image.
A calcification extraction image acquisition unit that obtains a calcification extraction image by performing a calcification extraction process on the breast radiation image for each imaging direction acquired by the radiological image acquisition unit;
The breast radiographic image capturing apparatus according to claim 4, further comprising a composite image generation unit that generates a composite image by superimposing the subtraction image and the calcification extraction image for each imaging direction.
After the radiation irradiating unit irradiates the plurality of different radiations in the first imaging direction, the radiation irradiation unit radiates the plurality of different radiations in a second imaging direction different from the first imaging direction. The breast radiographic imaging device according to any one of claims 4 to 6, wherein
The low-resolution processing part which performs the process which lowers | hangs the resolution with respect to the breast radiographic image after the contrast agent injection | pouring acquired by the said radiographic image acquisition part is provided, The any one of Claim 3 to 7 characterized by the above-mentioned. Breast radiation imaging device.
The breast radiation image capturing apparatus according to claim 8, further comprising an instruction receiving unit that receives instruction information indicating whether or not to perform the process of reducing the resolution.
The instruction information for performing the process for reducing the resolution is information indicating that the contrast medium has been applied to the breast, and the instruction information for not performing the process for reducing the resolution is input of the contrast medium to the breast. The breast radiographic image capturing apparatus according to claim 9, wherein the radiographic image capturing apparatus is information indicating that the operation is not performed.
11. The radiation dose reduction unit according to claim 8, wherein the radiation irradiating unit lowers the radiation dose when performing the process of reducing the resolution than when not performing the process of reducing the resolution. Breast radiographic imaging device.
The breast radiation according to any one of claims 3 to 7, further comprising a readout control unit that controls to perform binning readout when reading out the breast radiation image after the contrast medium is fed from the radiation image detector. Image shooting device.
The breast radiation image capturing apparatus according to claim 11, further comprising an instruction receiving unit that receives instruction information indicating whether or not to perform the binning readout.
The instruction information for performing the binning readout is information indicating that the contrast medium has been put into the breast, and the instruction information for not performing the binning readout does not carry out the contrast medium into the breast. The breast radiographic image capturing apparatus according to claim 12, wherein the information is information indicating the fact.
The breast radiation image according to any one of claims 12 to 14, wherein the radiation irradiation unit lowers the dose of the radiation when performing the binning readout than when not performing the binning readout. Shooting device.
The breast radiographic imaging apparatus according to any one of claims 3 to 15, further comprising a biopsy needle unit having a biopsy needle inserted into the breast.