JP2012157551A - Radiation image photographing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform reconstruction using a plurality of radiation images in consideration of even pixel density of the acquired radiation images when performing photography from a plurality of photographing directions to acquire the plurality of radiation images.SOLUTION: A photographic condition setting part 2c sets a radiation dose and a pixel density of a radiation image to be acquired when performing photography from a prescribed photographing direction of the plurality of photographing directions to be larger than a radiation dose and a radiation image to be acquired when performing photography from another direction different from the prescribed photographing direction. A pixel density conversion part 2d converts the first radiation image acquired by performing the photography from the prescribed photographing direction into the same pixel density as the second radiation image acquired by performing the photography from the other photographing direction. An image processing part 2c applies image processing for compensating a difference in the radiation dose with the second radiation image to the first radiation image. A reconstruction part 2f reconstructs the first radiation image which is applied with the image processing and wherein the pixel density is converted, and the second radiation image to generate a tomographic image.

Description

  The present invention relates to a radiographic imaging apparatus and method for acquiring a plurality of radiographic images by imaging a subject from a plurality of different imaging directions.

  As an apparatus for displaying a medical image such as a radiographic image, an apparatus for displaying a stereoscopic image (three-dimensional image, stereo image) based on two radiographic images including parallax information between the left and right eyes has been proposed. Such a stereoscopic image is obtained by irradiating a subject with radiation from different directions, detecting radiation transmitted through the subject with a radiation detector, and obtaining a plurality of radiation images having parallax with each other. Displayed stereoscopically based on the image. By displaying the stereoscopic image in such a manner that the stereoscopic image can be viewed in a stereoscopic manner, it is possible to observe a radiographic image with a sense of depth, thereby making it easier to make a diagnosis.

  In addition, in a radiographic imaging device, in order to observe the affected area in more detail, the radiation source is moved, the subject is irradiated with radiation from a plurality of different directions, and imaging is performed. Tomosynthesis photography that can obtain an image in which the cross section is emphasized has been proposed. In tomosynthesis imaging, depending on the characteristics of the imaging device and the required tomographic image, the radiation source can be moved in parallel with the radiation detector, or moved in a circle or ellipse arc to create different irradiation angles. A plurality of radiographic images are acquired by imaging the subject at the irradiation position, and a tomographic image is generated by reconstructing these radiographic images using a simple backprojection method or a backprojection method such as a filter backprojection method. .

  When performing such tomosynthesis imaging, there is a technique in which the radiation intensity from the direction perpendicular to the detection surface of the radiation detector is made larger than the radiation intensity from other directions, and the radiation image acquired at that position is used for display. It has been proposed (see Patent Document 1). In addition, when performing tomosynthesis imaging, there has also been proposed a method for correcting a radiographic image in order to compensate for differences in image quality of a plurality of acquired images when radiation doses from a plurality of imaging directions are different (patents) References 2 and 3). Furthermore, a method of switching between normal imaging and stereo imaging for acquiring a stereoscopic image has been proposed in an imaging apparatus that emits radiation from a plurality of imaging directions (see Patent Document 4).

JP 2007-75615 A JP 2010-119507 A JP 201-119437 A Japanese Unexamined Patent Publication No. 1-224696

  Here, in the methods described in Patent Documents 1 to 3, the radiographic image obtained by imaging from the imaging direction with a large radiation dose has high-definition image quality suitable for observation, and the pixel density is also high. It is larger than a radiographic image acquired by performing imaging from another imaging direction. For this reason, in the methods described in Patent Documents 2 and 3, a plurality of radiographic images are reconstructed after performing correction to make the image quality of the plurality of acquired radiographic images the same. However, in the methods described in Patent Documents 2 and 3, since correction is performed so as to compensate only for the difference in image quality of the radiation image, the difference in pixel density cannot be offset.

  The present invention has been made in view of the above circumstances, and when acquiring a plurality of radiographic images by performing imaging from a plurality of imaging directions, a plurality of radiographic images are used in consideration of the pixel density of the acquired radiographic images. The purpose is to perform reconfiguration.

A radiographic imaging apparatus according to the present invention includes a radiation irradiating means for irradiating a subject with radiation,
Radiation detecting means for detecting radiation that has been irradiated by the radiation irradiating means and transmitted through the subject to obtain a radiation image of the subject; and
Imaging control means for controlling the radiation irradiating means and the radiation detecting means to irradiate the subject from a plurality of imaging directions and to acquire a plurality of radiation images having different imaging directions due to the irradiation of the radiation,
Among the plurality of imaging directions, the radiation dose when acquiring from the predetermined imaging direction and the pixel density of the acquired radiographic image, and the radiation dose and acquiring when imaging from another direction different from the predetermined imaging direction Imaging condition setting means for setting larger than the pixel density of the radiation image to be
Of the first radiographic image acquired by imaging from the predetermined imaging direction and the second radiographic image acquired by imaging from the other imaging direction, the first radiographic image Image processing means for performing image processing for compensating for a difference in the radiation dose from the second radiation image;
Pixel density conversion means for converting the first radiographic image into the same pixel density as the second radiographic image;
Reconstructing means for generating a tomographic image by reconstructing the first radiographic image and the second radiographic image that have been subjected to the image processing and whose pixel density has been converted. It is what.

In the radiographic image capturing apparatus according to the present invention, a grid for removing the scattered radiation of the radiation inserted between the subject and the radiation detecting means when performing imaging from the predetermined imaging direction. Further comprising
The image processing for compensating for the difference in radiation dose may be processing for blurring the first radiation image.

  The radiographic imaging device according to the present invention may further include display means for displaying the first radiographic image.

  In the radiographic image capturing apparatus according to the present invention, when the predetermined imaging direction is two directions, a stereoscopic image based on the two first radiographic images acquired by performing imaging from the two directions is displayed. It is good also as what further has the stereoscopic vision image display means to do.

A radiographic imaging method according to the present invention includes a radiation irradiation means for irradiating a subject with radiation,
Radiation detecting means for detecting radiation that has been irradiated by the radiation irradiating means and transmitted through the subject to obtain a radiation image of the subject; and
An imaging control means for controlling the radiation irradiating means and the radiation detecting means so as to irradiate the subject with the radiation from a plurality of imaging directions and to acquire a plurality of radiation images having different imaging directions due to the irradiation of the radiation; A radiographic imaging method in a radiographic imaging device provided, comprising:
Among the plurality of imaging directions, the radiation dose when acquiring from the predetermined imaging direction and the pixel density of the acquired radiographic image, and the radiation dose and acquiring when imaging from another direction different from the predetermined imaging direction Setting larger than the pixel density of the radiation image to be performed,
Of the first radiographic image acquired by imaging from the predetermined imaging direction and the second radiographic image acquired by imaging from the other imaging direction, the first radiographic image Applying image processing for compensating for the difference in radiation dose from the second radiation image;
Converting the first radiation image to the same pixel density as the second radiation image;
And a step of generating a tomographic image by reconstructing the first radiographic image and the second radiographic image in which the pixel density is converted while performing the image processing. It is.

  According to the present invention, among a plurality of photographing directions, when photographing from another direction in which the radiation amount when photographing from a predetermined photographing direction and the pixel density of the acquired radiation image are different from the predetermined photographing direction. And the pixel density of the radiographic image to be acquired. And with respect to the first radiographic image of the first radiographic image acquired by performing imaging from a predetermined imaging direction and the second radiographic image acquired by performing imaging from another imaging direction, Image processing that compensates for the difference in radiation dose from the second radiation image is performed, and the first radiation image is converted to the same pixel density as the second radiation image. Then, image processing is performed, and a tomographic image is generated by reconstructing the first radiographic image and the second radiographic image in which the pixel density is converted. For this reason, the difference in pixel density as well as the difference in image quality between the first and second radiographic images can be eliminated, whereby a high-quality tomographic image can be acquired. In particular, by making the pixel density of the first radiographic image the same as the pixel density of the second radiographic image, it is possible to reduce the amount of computation during reconstruction as compared to the case where the first radiographic image is used as it is. The reconstruction process can be performed at high speed.

  In addition, when a grid is used when performing imaging from a predetermined imaging direction, the image processing that compensates for the difference in radiation dose is a process that blurs the first radiation image, so that the first due to the presence or absence of the grid. And the difference in graininess between the second radiographic images becomes inconspicuous. Therefore, a high-quality tomographic image can be acquired.

  Further, by displaying the first radiographic image, it is possible to satisfactorily perform diagnosis or the like using a high-definition radiographic image.

  Further, when the predetermined imaging direction is two directions, a high-definition stereoscopic image is used by displaying a stereoscopic image based on the two first radiation images acquired by performing imaging from these two directions. Diagnosis and the like can be performed satisfactorily.

1 is a schematic configuration diagram of a radiographic imaging device according to an embodiment of the present invention. The figure which looked at the arm part of the radiographic imaging apparatus shown in FIG. 1 from the right direction of FIG. The block diagram which shows schematic structure inside the computer of the radiographic imaging apparatus shown in FIG. A flowchart showing processing performed in the present embodiment The figure for explaining the shooting direction at the time of tomosynthesis shooting

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a radiographic imaging apparatus according to an embodiment of the present invention. The radiographic imaging apparatus 1 performs tomosynthesis imaging in which a breast M is captured from different imaging directions to obtain a plurality of radiographic images in order to generate a tomographic image of the breast. In addition, during tomosynthesis imaging, two radiographic images with different imaging directions for displaying a stereo image for stereoscopically viewing the radiographic image of the breast are also acquired.

  As shown in FIG. 1, the radiographic imaging device 1 includes an imaging unit 10, a computer 2 connected to the imaging unit 10, a monitor 3 connected to the computer 2, and an input unit 4.

  The imaging unit 10 includes a base 11, a rotary shaft 12 that is movable in the vertical direction (Z direction) with respect to the base 11, and a rotatable rotation shaft 12 and an arm portion 13 that is connected to the base 11 by the rotation shaft 12. I have. FIG. 2 shows the arm 13 viewed from the right direction in FIG.

  The arm portion 13 has an alphabet C shape, and a radiation table 16 is attached to one end of the arm portion 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.

  A radiation detector 15 such as a flat panel detector and a detector controller 33 that controls reading of a charge signal from the radiation detector 15 are provided inside the imaging table 14.

  The imaging table 14 includes a charge amplifier that converts the charge signal read from the radiation detector 15 into a voltage signal, a correlated double sampling circuit that samples the voltage signal output from the charge amplifier, and a voltage signal. A circuit board or the like provided with an AD conversion unit for converting 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 detector 15 can repeatedly perform recording and reading of a radiation image, and may use a so-called direct type radiation detector that directly receives radiation to generate charges, or radiation. May be used as a so-called indirect radiation detector that converts the light into visible light and converts the visible light into a charge signal. 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 a radiation image is emitted by irradiating reading light. It is desirable to use a so-called optical readout system in which a signal is read out, but the present invention is not limited to this, and other systems may be used.

  A radiation source 17 and a radiation source controller 32 are housed inside the radiation irradiation unit 16. The radiation source controller 32 controls the timing of irradiating radiation from the radiation source 17 and the radiation generation conditions (tube current, time, tube current time product, etc.) in the radiation source 17.

  Further, in the central portion of the arm portion 13, a compression plate 18 that is disposed above the imaging table 14 and presses against the breast M, a support portion 20 that supports the compression plate 18, and a support portion 20 are arranged 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.

  A grid 24 for removing scattered radiation of radiation that has passed through the breast M is disposed above the imaging table 14. The grid 24 prevents radiation scattered by the breast M from being applied to the radiation detector 15. For example, lead and the like that do not transmit radiation and aluminum and wood that are easily transmitted at a fine pitch of about 10 pieces / mm are alternately arranged. The grid 24 can be taken in and out of the imaging table 14 by a grid controller 35. The grid controller 35 operates under the control of the computer 2 described later, and puts the grid 24 in and out of the imaging table 14.

  The computer 2 includes a central processing unit (CPU) and a storage device such as a semiconductor memory, a hard disk, and an SSD. The control unit 2a, the radiation image storage unit 2b, and the radiographing unit shown in FIG. A condition setting unit 2c, a pixel density conversion unit 2d, an image processing unit 2e, a reconstruction unit 2f, and a display control unit 2g are configured.

  The control part 2a outputs a predetermined control signal with respect to various controllers 31-35, and controls the whole apparatus. A specific control method will be described later. Note that the control unit 2a corresponds to a photographing control unit.

  As will be described later, the radiological image storage unit 2b stores a plurality of radiographic images (Gi (i = 1 to n)) detected by the radiation detector 15 by imaging from a plurality of imaging directions for performing tomosynthesis imaging. It is something to remember.

  The imaging condition setting unit 2c determines the breast from the imaging direction of 0 degrees perpendicular to the detection surface of the radiation detector 15 and the imaging direction of +4 degrees (referred to as the first imaging direction) among a plurality of imaging directions. When imaging M, the amount of radiation emitted from the radiation source 17 and the pixel density when the detector controller 33 reads out a radiation image from the radiation detector 15 are other than the imaging directions of 0 degrees and +4 degrees. The imaging conditions are set so as to be larger than the radiation dose and the pixel density when imaging from the direction (second imaging direction). For example, as the radiation dose, when the number of imaging directions is 10, the radiation dose from the first imaging direction is set to 10 times the radiation dose from the second imaging direction, and the pixel density is When the pixel density of the radiographic image captured from the second imaging direction is 2M, the pixel density of the radiographic image captured from the first imaging direction is set to 5M. Here, the radiation dose and the pixel density when photographing from the first photographing direction of 0 degree and +4 degrees are the same as those when photographing from the first radiation dose, the first pixel density, and the second photographing direction. The radiation dose and the pixel density are referred to as a second radiation dose and a second pixel density. The set first and second radiation doses and the first and second pixel densities are stored in the storage unit of the computer 2.

  When performing reconstruction for generating a tomographic image as will be described later, the pixel density conversion unit 2d performs, for example, thinning out pixels or performing an interpolation operation to reduce the image, thereby performing the first radiation image The pixel density is converted to be the same as the pixel density of the second radiation image.

  The image processing unit 2e acquires two radiographic images acquired by performing imaging from the first imaging direction (hereinafter referred to as first radiographic images) by imaging from the second imaging direction. Image processing is performed so as to compensate for a difference in radiation dose from a radiation image (hereinafter referred to as a second radiation image). Details of the image processing will be described later.

  The reconstruction unit 2f generates a tomographic image in which a desired cross section of the breast M is emphasized by reconstructing the first radiographic image and the second radiographic image that have been subjected to image processing with the pixel density converted. To do. Specifically, the reconstruction unit 2f reconstructs these radiation images using a back projection method such as a simple back projection method or a filtered back projection method, and generates a tomographic image.

  The display control unit 2g performs a predetermined process for three-dimensional display on the two first radiographic images read from the radiographic image storage unit 2b, and then displays a stereo image of the breast M on the monitor 3 It is something to be made. In addition, the tomographic image generated by the reconstruction unit 2 f is displayed on the monitor 3.

  The monitor 3 is configured to display a stereo image based on the two first radiation images output from the computer 2 in a three-dimensional manner or to display a tomographic image generated by the reconstruction unit 2f. Is. As a three-dimensional display method of the monitor 3, for example, two radiographic images are respectively displayed using two screens, and one of these radiographic images is displayed on the right eye of the observer by using a half mirror or polarizing glass. It is possible to adopt a method in which a stereo image is displayed by making the other radiation image incident on the left eye of the observer. Moreover, you may use the system which displays a stereo image by superimposing two radiographic images and observing this with a polarizing glass. Further, the monitor 3 may be configured by 3D liquid crystal, and a system capable of displaying two radiation images in a three-dimensional manner, such as a parallax barrier system and a lenticular system, may be used.

  The input unit 4 is configured by a pointing device such as a keyboard and a mouse, for example, and receives an input of shooting conditions and an input of a shooting start instruction by an operator.

  Next, processing performed in the present embodiment will be described. FIG. 4 is a flowchart showing processing performed in the present embodiment. First, the patient's breast M is placed on the imaging table 14, and the breast M is compressed with a predetermined pressure by the compression plate 18 (step ST1). Next, after various shooting conditions are input at the input unit 4, an instruction to start shooting is input (step ST2).

  When there is an instruction to start imaging in the input unit 4, tomosynthesis imaging for acquiring a plurality of radiation images for generating a tomographic image of the breast M is performed. Note that tomosynthesis imaging according to the present embodiment includes imaging of two radiation images (stereo imaging) for displaying a stereo image. Specifically, first, the controller 2a resets the imaging direction for moving the radiation source 17 (i = 1, step ST3), and moves the radiation source 17 to the radiation source position that is the current imaging direction. The shooting direction angle θi is read out, and information on the read shooting direction angle θi is output to the arm controller 31. Then, the arm controller 31 receives information on the shooting direction angle θi output from the control unit 2 a, and the arm controller 31 outputs a control signal for rotating the arm unit 13 to the arm controller 31. Here, when i = 1, as shown in FIG. 5, a control signal for rotating the arm unit 13 is output to the arm controller 31 so that the radiation source 17 moves to the initial position P1 that is the initial imaging direction. And according to the control signal output from this arm controller 31, the arm part 13 rotates and moves the radiation source 17 to the radiation source position used as the present imaging direction (step ST4).

  Then, the control unit 2a determines whether or not the current shooting direction is the first shooting direction (step ST5). FIG. 5 shows seven radiation source positions P1 to P7. If the angle formed by the optical axis of the radiation source 17 at the adjacent radiation source position is 4 degrees, the radiation source 17 is at positions P4 and P5. The shooting direction in a certain case is the first shooting direction, and the shooting direction in the other positions P1 to P3, P6, and P7 is the second shooting direction.

  If step ST5 is negative, that is, if the current imaging direction is the second imaging direction, the second radiographic image is captured (step ST6). Specifically, the control unit 2a irradiates the radiation source controller 32 with a second radiation dose and obtains a second radiation image having a second pixel density with respect to the detector controller 33. The control signal is output so as to read out the radiation image signal. Further, a control signal is output to the grid controller 35 so that the grid 24 is retracted from the imaging table 14. Here, when the second radiation image is captured, the grid 24 is not used because the radiation is incident from a direction having an angle with respect to the incident surface of the grid 24 when the second radiation image is captured. For this reason, a large amount of radiation is scattered by the grid 24, and a sufficient dose of radiation does not reach the breast M, so that the image quality of the acquired second radiation image is degraded.

  In response to this control signal, the grid 24 is retracted from the imaging table 14, radiation of the second radiation dose is emitted from the radiation source 17, and a radiation image obtained by imaging the breast M from the current imaging direction is a radiation detector 15. The radiation image signal is read out from the radiation detector 15 by the detector controller 33 so as to obtain a radiation image having the second pixel density, and predetermined signal processing is performed on the radiation image signal. After that, it is stored as a radiation image Gi in the radiation image storage unit 2b of the computer 2.

  On the other hand, when step ST5 is affirmed, that is, when the current imaging direction is the first imaging direction, imaging of the first radiation image is performed (step ST7). Specifically, the control unit 2a irradiates the radiation source controller 32 with a first radiation dose so that a first radiation image having a first pixel density is obtained with respect to the detector controller 33. A control signal is output so as to read out the radiation image signal. Further, a control signal is output to the grid controller 35 so that the grid 24 is positioned on the imaging table 14.

  In response to this control signal, the grid 24 is moved onto the imaging table 14, the radiation of the first radiation dose is emitted from the radiation source 17, and the radiation image obtained by imaging the breast M from the current imaging direction is the radiation detector 15. The radiation image signal is read out from the radiation detector 15 by the detector controller 33 so as to obtain a radiation image having the first pixel density, and predetermined signal processing is performed on the radiation image signal. After that, it is stored as a radiation image Gi in the radiation image storage unit 2b of the computer 2.

  Next, the controller 2a determines whether or not shooting from all shooting directions has been completed (step ST8). If step ST8 is negative, the shooting direction is set to the next shooting direction (i = i + 1). ), Step ST9), the process returns to Step ST4, and the processes after Step ST4 are repeated.

  When step ST8 is affirmed, in order to reconstruct a plurality of radiographic images Gi and generate a tomographic image, the first radiographic image is read out of the radiographic images Gi stored in the radiographic image storage unit 2b. In the pixel density conversion unit 2d, the pixel density of the first radiographic image is converted so as to be the same as the pixel density of the second radiographic image (step ST10). Further, in the image processing unit 2e, predetermined image processing is performed on the first radiation image whose pixel density has been converted (step ST11). Here, when the radiographic image Gi is the first radiographic image, the radiation dose at the time of imaging is larger than that of the second radiographic image, and thus the density and contrast are higher than those of the second radiographic image. Further, although random noise is smaller than that of the second radiation image, since the radiographing is performed using the grid 24, the granularity is different from that of the second radiation image.

  For this reason, when the radiographic image Gi is the first radiographic image, the image processing unit 2e sets the contrast and density of the radiographic image Gi to compensate for the difference in the radiation dose from the second radiographic image. The processed radiographic image Gi is acquired by performing the process of combining with the radiographic image of 2, the process of blurring the image, and the process of adding random noise. In this embodiment, since the pixel density is converted before the image processing, the amount of calculation for the image processing can be reduced. However, the image processing is performed first, and the pixel density is converted after the image processing. Also good. Further, at least one of a process of matching the contrast and density with the second radiation image, a process of blurring the image, and a process of adding random noise may be performed.

  Then, the second radiation image is read out from the radiation image Gi stored in the radiation image storage unit 2b, and the first radiation image and the processed second radiation image are reconstructed in the reconstruction unit 2f. Thus, a tomographic image is generated (step ST12). At this time, since the pixel density of the first radiographic image is converted so as to be the same as the pixel density of the second radiographic image, the reconstructed image is compared with the case where the first radiographic image is used as it is. Therefore, it is possible to reduce the calculation amount. The generated tomographic image is displayed on the monitor 3 (step ST13).

  Furthermore, when there is an instruction to display a stereo image (step ST14), the two first radiographic images stored in the radiographic image storage unit 2b are read out and output to the monitor 3, and the monitor 3 A stereo image is displayed (step ST15).

  As described above, according to the present embodiment, the first radiographic image is subjected to image processing that compensates for the difference in radiation dose at the time of imaging with the second radiographic image, and the first radiographic image is converted into the second radiographic image. The tomographic image is generated by converting to the same pixel density as that of the radiographic image, performing image processing, and reconstructing the first radiographic image and the second radiographic image with the pixel density converted. It is a thing. For this reason, the difference in image quality and the difference in pixel density between the first and second radiographic images can be eliminated, whereby a high-quality tomographic image can be acquired. In particular, by making the pixel density of the first radiographic image the same as the pixel density of the second radiographic image, it is possible to reduce the amount of computation during reconstruction as compared to the case where the first radiographic image is used as it is. The reconstruction process can be performed at high speed.

  In the above embodiment, two first radiographic images for displaying a stereo image are acquired during tomosynthesis imaging, but one radiographic image for displaying a two-dimensional image instead of the stereo image is acquired. May be acquired as the first radiation image. In this case, it is preferable that the imaging direction for acquiring the first radiation image is a direction perpendicular to the detection surface of the radiation detector 15.

  In the above embodiment, the grid 24 is used when acquiring the first radiographic image. However, the first radiographic image may be acquired by performing imaging without using the grid 24. Good. In this case, since the difference in graininess caused by the grid 24 is small between the first radiographic image and the second radiographic image, it is not necessary to perform a process of blurring the image during image processing.

  Moreover, in the said embodiment, although the radiographic imaging apparatus of this invention is set as the apparatus which image | photographs the radiographic image of a breast, it is not restricted to a breast as a subject, For example, the radiographic imaging apparatus which image | photographs a chest, a head, etc. It is also possible to use.

DESCRIPTION OF SYMBOLS 1 Radiographic imaging device 2 Computer 2a Control part 2b Radiation image storage part 2c Imaging condition setting part 2d Pixel density conversion part 2e Image processing part 2f Reconstruction part 2g Display control part 3 Monitor 4 Input part 10 Imaging part 13 Arm part 14 Imaging | photography Table 15 Radiation detector 16 Radiation irradiation unit 17 Radiation source 18 Compression plate 24 Grid

Claims (5)

Radiation irradiation means for irradiating the subject with radiation;
Radiation detecting means for detecting radiation that has been irradiated by the radiation irradiating means and transmitted through the subject to obtain a radiation image of the subject; and
Imaging control means for controlling the radiation irradiating means and the radiation detecting means to irradiate the subject from a plurality of imaging directions and to acquire a plurality of radiation images having different imaging directions due to the irradiation of the radiation,
Among the plurality of imaging directions, the radiation dose when acquiring from the predetermined imaging direction and the pixel density of the acquired radiographic image, and the radiation dose and acquiring when imaging from another direction different from the predetermined imaging direction Imaging condition setting means for setting larger than the pixel density of the radiation image to be
Of the first radiographic image acquired by imaging from the predetermined imaging direction and the second radiographic image acquired by imaging from the other imaging direction, the first radiographic image Image processing means for performing image processing for compensating for a difference in the radiation dose from the second radiation image;
Pixel density conversion means for converting the first radiographic image into the same pixel density as the second radiographic image;
Reconstructing means for generating a tomographic image by reconstructing the first radiographic image and the second radiographic image that have been subjected to the image processing and whose pixel density has been converted. A radiographic imaging device. A grid for removing scattered radiation of the radiation, which is inserted between the subject and the radiation detection means when performing imaging from the predetermined imaging direction;
The radiographic image capturing apparatus according to claim 1, wherein the image processing for compensating for the difference in radiation dose is processing for blurring the first radiographic image.   The radiographic image capturing apparatus according to claim 1, further comprising display means for displaying the first radiographic image.   In the case where the predetermined imaging direction is two directions, a stereoscopic image display means for displaying a stereoscopic image based on the two first radiation images acquired by performing imaging from the two directions is further provided. The radiographic imaging device according to any one of claims 1 to 3, wherein Radiation irradiation means for irradiating the subject with radiation;
Radiation detecting means for detecting radiation that has been irradiated by the radiation irradiating means and transmitted through the subject to obtain a radiation image of the subject; and
An imaging control means for controlling the radiation irradiating means and the radiation detecting means so as to irradiate the subject with the radiation from a plurality of imaging directions and to acquire a plurality of radiation images having different imaging directions due to the irradiation of the radiation; A radiographic imaging method in a radiographic imaging device provided, comprising:
Among the plurality of imaging directions, the radiation dose when acquiring from the predetermined imaging direction and the pixel density of the acquired radiographic image, and the radiation dose and acquiring when imaging from another direction different from the predetermined imaging direction Setting larger than the pixel density of the radiation image to be performed,
Of the first radiographic image acquired by imaging from the predetermined imaging direction and the second radiographic image acquired by imaging from the other imaging direction, the first radiographic image Applying image processing for compensating for the difference in radiation dose from the second radiation image;
Converting the first radiation image to the same pixel density as the second radiation image;
And a step of generating a tomographic image by reconstructing the first radiographic image and the second radiographic image in which the image density is converted and the pixel density is converted. Image shooting method.

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