WO2019064351A1

WO2019064351A1 - Radiograph processing device for medical use, and radiography device

Info

Publication number: WO2019064351A1
Application number: PCT/JP2017/034797
Authority: WO
Inventors: 淳也山本; 隆大宮島; 和義西野
Original assignee: 株式会社島津製作所
Priority date: 2017-09-26
Filing date: 2017-09-26
Publication date: 2019-04-04
Also published as: JPWO2019064351A1; TW201915593A; JP6729812B2; TWI682231B

Abstract

This radiography device (1) for medical use is provided with a reconstructed image generating unit (13) that, if physical movement by an object (O) is detected in some of multiple radiographic images (15), excludes the radiographic images (15) in which the physical movement by the object (O) was detected and then generates a reconstructed image (16) obtained by reconstructing the non-excluded multiple radiographic images (15) into a single image.

Description

Medical X-ray image processing apparatus and X-ray imaging apparatus

The present invention relates to a medical X-ray image processing apparatus and an X-ray imaging apparatus, and more particularly to a medical X-ray image processing apparatus and an X-ray imaging apparatus which reconstruct one image from a plurality of X-ray radiographed images.

BACKGROUND Conventionally, a medical X-ray image processing apparatus and an X-ray imaging apparatus that reconstruct one image from a plurality of X-ray images are known. An X-ray imaging apparatus provided with such a medical X-ray imaging apparatus is disclosed, for example, in Japanese Patent No. 5504143.

In general, when one image is reconstructed from a plurality of X-ray radiographed images, if there is body movement between the images, the image quality of the obtained image is degraded if it is reconstructed as it is. Therefore, in the X-ray imaging apparatus disclosed in Japanese Patent No. 5504143, when body movement of the subject is detected in the X-ray imaging image, the position correction of the subject is performed, and then reconstruction is performed. A configuration to perform is disclosed.

However, depending on the amount of movement of the subject, position correction may not be possible. Therefore, in the X-ray imaging apparatus disclosed in Japanese Patent No. 5504143, the imaging is interrupted when the amount of movement of the subject is equal to or more than a predetermined threshold.

Patent No. 5504143

However, since the X-ray imaging apparatus disclosed in the above-mentioned Japanese Patent No. 5504143 interrupts imaging when the body movement of the subject exceeds the threshold value, there is a possibility that the chance of performing reconstruction may be reduced. There is a problem. In that case, it will be necessary to redo imaging, and the exposure dose of the subject is likely to increase. Therefore, it is desirable to be able to reconstruct as much as possible even when body movement of a subject is detected.

The present invention has been made to solve the problems as described above, and one object of the present invention is to re-execute even when body movement of a subject is detected in part of a plurality of X-ray images. Abstract: A medical X-ray image processing apparatus and an X-ray imaging apparatus capable of suppressing a decrease in the opportunity to perform configuration.

In order to achieve the above object, a medical X-ray image processing apparatus according to a first aspect of the present invention comprises an image acquisition unit for acquiring a plurality of X-ray imaging images obtained by X-ray imaging; Information on the movement of the subject based on the position information acquisition unit for acquiring the position information of the phantom and the position information of the subject appearing in the image, and the position information of the phantom and the position information of the subject in each of the plurality of X-ray radiographed images When the body movement of the subject is detected in part of a plurality of X-ray images, the X-ray imaging image in which the body movement of the subject is detected is excluded, and the imaging system And a reconstructed image generation unit configured to generate a reconstructed image by reconstructing a plurality of X-ray radiographed images captured while changing the relative position to the subject.

As described above, the medical X-ray image processing apparatus according to the first aspect of the present invention includes the reconstructed image generation unit that generates the reconstructed image by excluding the X-ray imaging image in which the body movement of the subject is detected. . As a result, even when body movement of the subject is detected in part of the plurality of X-ray radiographed images, the image in which body movement is detected can be excluded and reconstruction can be performed. As a result, even if body movement of the subject is detected, if the number of images without body movement is necessary for reconstruction, the reconstructed image is used without using the image in which body movement of the subject is detected. Since generation is possible, it is possible to suppress deterioration in the image quality of the generated reconstructed image. In addition, since it is possible to generate a reconstructed image by excluding an image in which body motion of a subject is detected, it is possible to suppress a decrease in the chance of performing a reconstruction. In addition, since it is possible to generate a reconstructed image by excluding an image in which body movement of a subject is detected, it is possible to suppress the retaking of imaging as much as possible.

In the medical X-ray image processing apparatus according to the first aspect, preferably, the reconstructed image generation unit is configured to detect X-rays in which body motion of a subject in a plurality of X-ray radiographed images is detected based on information on body motion of the subject. When the degree of the number of captured images is less than the first threshold, the X-ray captured image in which the body movement of the subject is detected is excluded. According to this configuration, it is possible to exclude the image in which the body movement of the subject is detected from the reconstruction, according to the degree of the number of images in which the body movement of the subject is detected. As a result, since there is a trade-off between the number of images used for reconstruction and the image quality of the generated reconstructed image, it is possible to generate a reconstructed image without excessively degrading the image quality.

In this case, preferably, in the case where the reconstructed image generation unit determines that the number of X-ray captured images in which body movement of the subject in the plurality of X-ray captured images is detected is less than a second threshold smaller than the first threshold. Is configured to generate a reconstructed image without excluding an X-ray imaging image in which a body movement of a subject is detected. Here, depending on the number of images in which the body movement of the subject is detected, the image quality of the obtained reconstructed image may not be substantially affected even when the image is reconstructed as it is. That is, when the number of images in which body motion of the subject is detected in the total captured image is equal to or less than a predetermined number, the image quality of the reconstructed image may not substantially deteriorate. If configured as described above, even if there is an image in which body movement of a subject is detected, reconstruction can be performed without exclusion according to the degree of the number of images in which body movement is detected. As a result, it is possible to increase the number of X-ray radiographed images that can be used for the reconstructed image, and therefore, it is possible to suppress the degradation of the image quality of the reconstructed image.

In the medical X-ray image processing apparatus according to the first aspect, preferably, the reconstruction image generation unit determines that the number of X-ray imaging images in which body movement of the subject in the plurality of X-ray imaging images is detected. If larger than the threshold value, it is configured not to generate a reconstructed image. According to this configuration, when the degree of the number of X-ray images in which the body movement of the subject is detected is larger than the first threshold, the reconstruction can be suppressed. As a result, when it is predicted that the minimum necessary image quality can not be obtained even if reconstruction is performed excluding images in which body motion is detected, generation of a low-quality reconstructed image is suppressed. be able to.

In this case, preferably, the reconstructed image generation unit detects body motion of the subject when the ratio of the number of radiographed images in which body motion of the subject is detected among the plurality of radiographed images is less than a first threshold. It is configured to exclude reconstructed X-ray images to generate a reconstructed image. According to this configuration, the influence of the exclusion on the image quality can be appropriately evaluated by the ratio of the exclusion number to the total number. As a result, it is possible to properly determine whether or not to perform the reconfiguration.

In the medical X-ray image processing apparatus according to the first aspect, preferably, the information related to the body movement includes the body movement amount of the subject, and the reconstructed image generation unit generates X-rays for at least the excluded X-ray imaging image. The position of the subject in the X-ray imaging image is corrected based on the amount of movement of the subject in the imaging image, and whether to use for reconstruction is switched. According to this configuration, even in the case of an image in which body movement of a subject is detected, if the position correction can be performed based on the body movement amount of the subject, the number of images used for reconstruction is increased. It can be done. Therefore, the image quality of the image obtained by the reconstruction can be improved as compared with the case where the image in which the body movement of the subject is detected is excluded from the reconstruction without the position correction. In addition, since it is possible to exclude from the image used for reconstruction when it is not possible to perform position correction, it is possible to suppress degradation of the image quality of the reconstructed image.

In this case, preferably, the reconstructed image generation unit is configured to move the body motion of the subject when the body motion amount of the subject in the X-ray imaging image in which body motion of the subject in the plurality of X-ray imaging images is detected is equal to or more than a third threshold. The position of the subject in the detected X-ray imaging image is excluded from the reconstruction without being corrected. According to this structure, the X-ray image can be excluded from the reconstruction when the amount of body movement of the subject is equal to or more than the third threshold. As a result, it is possible to easily suppress that an X-ray image which can not be subjected to position correction is used for reconstruction.

In the medical X-ray image processing apparatus according to the first aspect, preferably, the reconstructed image generation unit is configured to set the amount of movement of the subject in the X-ray imaging image in which body movement of the object in the plurality of X-ray imaging images is detected. In the case of the fourth threshold which is less than the third threshold and smaller than the third threshold, the reconstructed image is generated by correcting the position of the subject in the X-ray imaging image in which the body movement of the subject is detected. According to this configuration, even in the image in which the body movement of the subject is detected, if the body movement amount is within the range of the predetermined threshold, the position correction can be performed and used for the reconstruction. As a result, since it is possible to increase the number of images used for reconstruction, the image quality of the reconstructed image can be improved.

In this case, preferably, the reconstructed image generation unit determines the position of the subject in the X-ray captured image in which the body motion of the subject is detected when the amount of body move of the subject in at least the excluded X-ray captured image is less than the fourth threshold. It is configured to be used to generate a reconstructed image without correction. According to this configuration, for example, when the amount of body movement is small to such an extent that there is no need to perform position correction, it can be used for generation of a reconstructed image without position correction. As a result, generation of a reconstructed image can be simplified as compared to the case where position correction is performed regardless of the degree of body movement.

In the medical X-ray image processing apparatus according to the first aspect, preferably, in a plurality of X-ray radiographed images continuously photographed, a total of the X-ray radiographed images at which body movement of the subject is detected is photographed. The X-ray imaging apparatus further includes an imaging switching unit that switches whether to interrupt or continue imaging in the X-ray imaging apparatus based on the imaging order with respect to the number of imaging. Here, in the case where shooting is usually performed continuously, once movement occurs, body movement will continue, so when the movement of the subject is detected at a timing earlier in the imaging order by the above configuration, Shooting can be interrupted. As a result, the exposure of the subject can be reduced. In addition, when body movement of the subject is detected at a timing when the photographing order is late after most of the images are taken, the photographing can be continued without interruption. As a result, for example, as compared with the case where imaging is performed again, it is not necessary to recapture a place where the body movement of the subject is not detected, so the exposure dose can be reduced.

In this case, preferably, the imaging switching unit moves the imaging system to the imaging position at which the body movement of the subject is detected when the body movement of the subject is detected in a part of the plurality of X-ray imaging images. It is configured to switch whether to shoot or not. With this configuration, when performing re-shooting, it is possible to perform re-shooting only where re-shooting is required, so unnecessary exposures are suppressed as compared to the case where all the re-shooting is performed again. be able to. Moreover, since it becomes possible to suppress performing unnecessary imaging | photography, when not performing imaging | photography again, unnecessary exposure can be suppressed.

An X-ray imaging apparatus according to a second aspect of the present invention comprises an X-ray source, a detector for detecting X-rays emitted from the X-ray source, and an X-ray from an intensity distribution of X-rays detected by the detector. An image processing unit that generates a captured image, and an imaging system position changing mechanism that changes the relative position of an imaging system including an X-ray source and a detector. The image processing unit captures an image in a plurality of X-ray images. The image processing unit is configured to acquire the position information of the phantom and the position information of the subject, and the image processing unit is configured to obtain information on the body movement of the subject based on the position information of the phantom and the position information of the subject in the plurality of X-ray radiographed images. The image processing unit is configured to determine the presence or absence of the body movement of the subject in each of the plurality of X-ray imaging images, and the image processing unit is configured to acquire the plurality of X-ray imagings. Captured on part of the image When a body movement of the subject is detected, the X-ray imaging image in which the body movement of the subject is detected is excluded, and a plurality of X-ray imaging images captured while changing the relative position of the imaging system to the subject Are configured to generate a reconstructed image reconstructed.

As described above, the X-ray imaging apparatus according to the second aspect of the present invention includes the image processing unit that generates the reconstructed image by excluding the X-ray imaging image in which the body movement of the subject is detected. As a result, even when body movement of the subject is detected in part of the plurality of X-ray radiographed images, the image in which body movement is detected can be excluded and reconstruction can be performed. As a result, even if body movement of the subject is detected, if the number of images without body movement is necessary for reconstruction, the reconstructed image is used without using the image in which body movement of the subject is detected. Since generation is possible, it is possible to suppress deterioration in the image quality of the generated reconstructed image. In addition, since it is possible to generate a reconstructed image by excluding an image in which body motion of a subject is detected, it is possible to suppress a decrease in the chance of performing a reconstruction. In addition, since it is possible to generate a reconstructed image by excluding an image in which body movement of a subject is detected, it is possible to suppress the retaking of imaging as much as possible.

According to the present invention, as described above, even when body motion of a subject is detected in a part of a plurality of X-ray radiographed images, medical X which can suppress a reduction in the chance of performing reconstruction can be suppressed. A linear image processing apparatus and an X-ray imaging apparatus can be provided.

FIG. 1 is a block diagram showing an overall configuration of an X-ray imaging apparatus including a medical X-ray imaging apparatus according to a first embodiment of the present invention. FIG. 1 is a block diagram showing an overall configuration of a medical X-ray image processing apparatus according to a first embodiment of the present invention. It is a schematic diagram for demonstrating the imaging method of the X-ray imaging image in the X-ray imaging device by 1st Embodiment of this invention. It is a schematic diagram for demonstrating the image which the X-ray-image imaging device by 1st Embodiment of this invention image | photographs, and a reconstruction image. FIG. 6 is a schematic view (A) to (D) of a captured image for explaining a method of generating a reconstructed image in the medical X-ray image processing apparatus according to the first embodiment of the present invention. It is a schematic diagram of the phantom used when imaging | photography the X-ray image in the X-ray-image imaging device by 1st Embodiment of this invention. FIGS. 7A to 7C are schematic views of photographed images for explaining a method of acquiring information on body movement when the subject has no body movement. FIGS. 7A to 7C are schematic views of photographed images for explaining a method of acquiring information on body movement when the subject has body movement. It is a schematic diagram for demonstrating the criterion (threshold value) which excludes an image, when a to-be-photographed object has a body motion. It is a flowchart for demonstrating the determination processing (subroutine) which reconfigure | reconstructs the X-ray imaging image by the medical X-ray-image processing apparatus by 1st Embodiment of this invention. It is a flowchart for demonstrating the handling determination processing (subroutine) of the X-ray captured image by the medical X-ray image processing apparatus by 1st Embodiment of this invention. FIG. 7 is a schematic diagram for describing a determination reference (threshold) for performing position correction of the subject when body movement is detected on the subject. It is a flowchart for demonstrating the handling determination processing (subroutine) of the X-ray imaging image by the medical X-ray image processing apparatus by 2nd Embodiment of this invention. It is the block diagram which showed the whole structure of the medical X-ray-image processing apparatus by 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the criterion (threshold value) which switches imaging | photography by the timing to which the body motion was detected to the to-be-photographed object. It is a flowchart for demonstrating the process which switches imaging | photography of the X-ray captured image by the medical X-ray-image processing apparatus by 3rd Embodiment of this invention. It is a flowchart for demonstrating the process of the imaging | photography switch determination by the medical X-ray-image processing apparatus by 3rd Embodiment of this invention. It is a flowchart for demonstrating the process which reconfigure | reconstructs the X-ray radiography image by the medical X-ray-image processing apparatus by the 1st modification of 1st Embodiment of this invention. It is a flowchart for demonstrating the process which performs position correction of the X-ray image by the medical X-ray-image processing apparatus by the 1st modification of 1st Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described based on the drawings.

First Embodiment
The configuration of an X-ray imaging apparatus 100 including the medical X-ray image processing apparatus 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 11.

(Configuration of X-ray imaging apparatus)
First, the configuration of an X-ray imaging apparatus 100 including the medical X-ray image processing apparatus 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic view of the X-ray imaging apparatus 100 as viewed from the Z direction. As shown in FIG. 1, the X-ray imaging apparatus 100 includes an X-ray source 2, a detector 3, a control unit 4, an imaging system position changing mechanism 5, and a medical X-ray image processing apparatus 1. In the present specification, the direction from the imaging system position changing mechanism 5 (X-ray source moving unit 5b) to the detector 3 is taken as a Y2 direction, and the opposite direction is taken as a Y1 direction. Further, the horizontal direction in the plane orthogonal to the Y direction is taken as the Z direction, the direction toward the back of the paper surface of FIG. 1 is taken as the Z2 direction, and the direction toward the near side of the paper surface of FIG. Further, the vertical direction in the plane orthogonal to the Y direction is the X direction, the upper direction is the X1 direction, and the lower direction is the X2 direction.

The X-ray source 2 generates X-rays by applying a high voltage. The X-ray source 2 is configured to irradiate the generated X-rays toward the detector 3.

The detector 3 is configured to detect an X-ray, convert the detected X-ray into an electrical signal, and read the converted electrical signal as an image signal. The detector 3 is, for example, an FPD (Flat Panel Detector). The detector 3 is composed of a plurality of conversion elements (not shown) and pixel electrodes (not shown) disposed on the plurality of conversion elements. The plurality of conversion elements and the pixel electrodes are arranged in the detector 3 such that the arrangement direction of the pixels coincides with the X direction and the Z direction at a predetermined period (pixel pitch). The detector 3 is also configured to output the acquired image signal to the medical X-ray image processing apparatus 1.

The medical X-ray image processing apparatus 1 is configured to generate an X-ray image 15 (see FIG. 4) based on the image signal output from the detector 3. In addition, the medical X-ray image processing apparatus 1 is configured to acquire position information of the phantom 6 and position information of the subject T which appear in the generated X-ray imaging image 15. Further, the medical X-ray image processing apparatus 1 is configured to acquire information on the body movement of the subject T based on the positional information of the phantom 6 and the positional information of the subject T in the X-ray imaging image 15. Further, the medical X-ray image processing apparatus 1 is configured to determine the presence or absence of body movement of the subject T in the X-ray imaging image 15. The medical X-ray image processing apparatus 1 is configured to generate a reconstructed image 16 (see FIG. 4) in which a plurality of X-ray radiographed images 15 are reconstructed into one image.

The medical X-ray image processing apparatus 1 includes, for example, a processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a field-programmable gate array (FPGA) configured for image processing. Details of a configuration in which the medical X-ray image processing apparatus 1 determines the presence or absence of body movement of the subject T and a configuration in which the reconstructed image 16 is generated will be described later. The medical X-ray image processing apparatus 1 is an example of the “image processing unit” in the claims.

The control unit 4 is configured to perform X-ray imaging by irradiating X-rays from the X-ray source 2 toward the detector 3. The control unit 4 is configured to change the relative position of the imaging system 7 with respect to the subject T by moving the X-ray source 2 via the imaging system position changing mechanism 5. Control unit 4 includes, for example, a CPU.

The imaging system position changing mechanism 5 is configured to change the relative position of the imaging system 7 consisting of the X-ray source 2 and the detector 3 and the angle of the X-ray source 2 based on the signal from the control unit 4 There is. The imaging system position changing mechanism 5 includes an X-ray source holding unit 5 a that rotatably holds the X-ray source 2. The imaging system position changing mechanism 5 also includes an X-ray source moving unit 5b that moves the X-ray source holding unit 5a in the X direction. The X-ray source holding unit 5a rotatably holds the X-ray source 2 at one end, and the other end is movably held by the X-ray source moving unit 5b. The X-ray source holding unit 5a is configured to be capable of pivoting the X-ray source 2 around an axis in the Z direction at one end. That is, the X-ray source holding unit 5 a is configured to be able to change the irradiation angle of the X-ray source 2 by the signal from the control unit 4. The X-ray source holding unit 5a includes, for example, a stepping motor, an encoder, and the like. Therefore, the X-ray source holding unit 5a can acquire the position and the orientation of the X-ray source 2. In addition, the X-ray source moving unit 5 b is configured to move the X-ray source holding unit 5 a in the X direction by a signal from the control unit 4. X-ray source moving unit 5b includes, for example, a motor and the like.

The X-ray imaging apparatus 100 is configured to generate a plurality of X-ray imaging images 15 by performing imaging while changing the relative position of the imaging system 7 via the imaging system position changing mechanism 5. The relative position of the imaging system 7 includes the position of the X-ray source 2 and the irradiation angle of the X-ray to the detector 3.

(Configuration of medical X-ray image processing apparatus)
FIG. 2 is a block diagram showing the entire configuration of the medical X-ray image processing apparatus 1. As shown in FIG. 2, the medical X-ray image processing apparatus 1 includes an image acquisition unit 10, a position information acquisition unit 11, a body movement information acquisition unit 12, a reconstructed image generation unit 13, and an X-ray imaging image generation. And a unit 14. The image acquisition unit 10, the position information acquisition unit 11, the body motion information acquisition unit 12, the reconstructed image generation unit 13, and the X-ray radiographed image generation unit 14 are FPGAs or the like of the medical X-ray image processing apparatus 1. It is configured as a processing module (processor) in the processor.

The image acquisition unit 10 is configured to acquire a plurality of X-ray captured images 15 obtained by X-ray imaging by the X-ray imaging apparatus 100. Specifically, the image acquisition unit 10 is configured to acquire an image signal detected by the detector 3. Further, the image acquisition unit 10 is configured to output the acquired image signal to the X-ray image generation unit 14.

The X-ray image generation unit 14 is configured to generate an X-ray image 15 based on the image signal output from the image acquisition unit 10. Further, the X-ray captured image generation unit 14 is configured to perform known correction processing accompanying imaging of the X-ray captured image 15.

The position information acquisition unit 11 is configured to acquire position information of the phantom 6 and position information of the subject T captured in the plurality of X-ray radiographed images 15 acquired by the image acquisition unit 10. In the first embodiment, the position information acquisition unit 11 is configured to acquire the position information of the phantom 6 and the position information of the subject T by image recognition processing.

The body motion information acquisition unit 12 is configured to acquire information related to body motion of the subject T based on the position information of the phantom 6 and the position information of the subject T in each of the plurality of X-ray radiographed images 15.

The reconstructed image generation unit 13 excludes the X-ray captured image 15 in which the body motion of the subject T is detected when the body motion of the subject T is detected in a part of the plurality of X-ray captured images 15 It is configured. In addition, the reconstruction image generation unit 13 is configured to generate a reconstruction image 16 in which a plurality of X-ray imaging images 15 captured while changing the relative position of the imaging system 7 with respect to the subject T are reconstructed into one image. It is done.

(Reconstructed image)
Next, with reference to FIGS. 3 to 5, a process in which the X-ray imaging apparatus 100 according to the first embodiment captures a plurality of X-ray images 15 and the medical X-ray image processing apparatus 1 performs a plurality of X-rays The process of reconstructing the image 15 will be described.

FIG. 3 is a schematic view when the X-ray imaging apparatus 100 according to the first embodiment captures a plurality of X-ray captured images 15. As shown in FIG. 3, in the first embodiment, the X-ray imaging apparatus 100 is configured to perform imaging while changing the relative position of the imaging system 7 with respect to the subject T by the imaging system position changing mechanism 5. Specifically, the imaging system position changing mechanism 5 is configured to move the X-ray source 2 in the X1 direction. Further, the imaging system position changing mechanism 5 is configured to change the X-ray irradiation direction of the X-ray source 2. Thus, the shooting system position changing mechanism 5 is configured to shoot while changing the relative position of the shooting system 7 to the subject T. The X-ray imaging apparatus 100 is an apparatus that performs so-called tomosynthesis.

FIG. 4 is a schematic view of an X-ray image 15 obtained at each relative position and a schematic view of a reconstructed image 16 obtained by reconstructing those images. As shown in FIG. 4, when the position where the imaging system 7 is disposed is different, the angle of the X-ray irradiated from the X-ray source 2 to the detector 3 changes, so the obtained X-ray imaging image 15 is also different. In the first embodiment, the medical X-ray image processing apparatus 1 is configured to generate a reconstructed image 16 by reconstructing a plurality of X-ray radiographed images 15 different in how the subject T appears in one image. It is done. The numerical values shown for the X-ray source 2 in FIG. 4 indicate the relative position of the imaging system 7 respectively. That is, the first to seventh relative positions are represented in order from the left side of FIG.

FIG. 5 shows a plurality of

internal structures

17a, 17b and positions in the Y direction which are substantially the same in the X direction and the Z direction among the subject T by the X-ray imaging apparatus 100 in the first embodiment. FIG. 14A is a schematic view of an X-ray image 15 obtained by imaging an area including 17c, and FIG. 5D is a schematic view of a reconstructed image 16 reconstructed by the medical X-ray image processing apparatus 1. FIG. That is, the internal structures 17a to 17c are internal structures 17 having different depth positions (positions in the Y direction) in any target region.

FIG. 5A shows an X-ray captured image 15a captured by arranging the imaging system 7 at the fourth relative position (see FIG. 4). FIG. 5B shows an X-ray image 15b taken with the imaging system 7 arranged at the sixth relative position (see FIG. 4). FIG. 5C shows an X-ray captured image 15c captured by arranging the imaging system 7 at the seventh relative position (see FIG. 4).

In the example shown in FIG. 5A, since the subject T is photographed from the Y1 direction, the internal structure 17a to the internal structure 17c of the subject T are photographed in an overlapping state. In the example shown in FIG. 5B, since the imaging system 7 is placed at the sixth relative position and imaged by the imaging system position changing mechanism 5, the X-rays enter the subject T from an oblique direction. Therefore, the internal structure 17a to the internal structure 17c are drawn out of position in the X2 direction. In the example shown in FIG. 5 (B), since the X-ray irradiation angle is small, the internal structure 17a to the internal structure 17c are depicted in a still overlapping state. In the example shown in FIG. 5C, since the imaging system 7 is arranged at the seventh relative position and imaged by the imaging system position changing mechanism 5, the imaging system 7 is arranged and imaged at the sixth relative position As compared with the case, the angle of the X-ray incident on the subject T becomes larger. Therefore, in the example shown in FIG. 5C, the internal structure 17a to the internal structure 17c are depicted without overlapping. The medical X-ray image processing apparatus 1 generates a reconstructed image 16 by reconstructing the X-ray images 15a to 15c. In the generation of the reconstructed image 16, a cross section at a desired depth position among the internal structure 17a to the internal structure 17c is imaged. Thus, the internal structure 17 at the desired depth position can be enhanced and imaged. The example shown in FIG. 5D is the reconstructed image 16 reconstructed focusing on the internal structure 17b.

Here, tomosynthesis is an imaging method on the premise that the subject T is at the same position between the respective images. Therefore, if there is body movement in the subject T between the images, the reconstruction may not be possible depending on the degree of body movement. Therefore, in the first embodiment, the reconstructed image generation unit 13 is configured to detect the body movement amount m (see FIG. 8) of the subject T and exclude the X-ray image 15 with body movement from the reconstruction. It is done. Specifically, the reconstructed image generation unit 13 determines the degree of the number of X-ray captured images 15 in which the body motion of the subject T is detected in the plurality of X-ray captured images 15 based on the information on the body motion of the subject T When it is less than the first threshold Th1 (see FIG. 9), the X-ray image 15 in which the body movement of the subject T is detected is excluded. In addition, when the ratio of the number of X-ray captured images 15 in which the body motion of the subject T is detected among the plurality of X-ray captured images 15 is less than the first threshold Th1, the reconstructed image generation unit 13 Are excluded from the X-ray image 15 detected to generate the reconstructed image 16. The first threshold Th1 can be set to any value within the range in which the image quality level permitted from the use purpose of the reconstructed image 16 can be secured. Further, the degree of the number of X-ray images 15 includes other than the ratio of the number of X-ray images 15. For example, when the total number of shots is determined in advance, if the number of shots is determined, the ratio of the numbers is determined. Therefore, when the total number of shots is predetermined, the number of shots is included in the number. In the first embodiment, the amount of body movement m refers to the parallel movement of the X-ray image 15 of the subject T in the XZ plane and the rotational movement around the Y axis in the XZ plane. It is a thing of several mm to several cm body movement.

In addition, the reconstructed image generation unit 13 sets a second threshold Th2 in which the degree of the number of X-ray captured images 15 in which body movement of the subject T is detected among the plurality of X-ray captured images 15 is smaller than the first threshold Th1 (see FIG. In the case of less than 9), the reconstructed image 16 is generated without excluding the X-ray image 15 in which the body movement of the subject T is detected. Note that the second threshold Th2 is an arbitrary value as long as the image quality of the reconstructed image 16 does not deteriorate even when the X-ray image 15 in which the body movement of the subject T is detected is not excluded and is reconstructed. Can be set.

In addition, when the degree of the number of X-ray captured images 15 in which body movement of the subject T is detected among the plurality of X-ray captured images 15 is larger than the first threshold Th1, the reconstructed image generation unit 13 It is configured not to generate

(Acquisition of information on body movement of the subject)
Next, a method for the medical X-ray image processing apparatus 1 according to the first embodiment to acquire information related to the body movement of the subject T will be described with reference to FIGS.

When imaging the subject T in the X-ray imaging apparatus 100, the phantom 6 is disposed and imaging is performed in order to use it as a reference for acquiring information on the body movement of the subject T. That is, by photographing the phantom 6 which does not move together with the subject T at the same time, it is possible to acquire information on the body movement of the subject T. In the first embodiment, the position information acquisition unit 11 is configured to acquire the position information of the phantom 6 and the position information of the subject T. Further, in the first embodiment, the body motion information acquisition unit 12 is configured to acquire information on body motion of the subject T based on the position information of the phantom 6 and the position information of the subject T. The position information of the phantom 6 and the position information of the subject T include coordinate values in the X-ray image 15. Further, the information related to the body movement of the subject T includes the body movement amount m of the subject T.

FIG. 6 is a schematic view of the phantom 6 to be used as a reference for acquiring information on body movement of the subject T in the X-ray imaging apparatus 100 according to the first embodiment. In the example shown in FIG. 6, the phantom 6 is made of resin or the like, and includes one X-ray absorber 60 for absorbing X-rays inside. Since the X-ray is absorbed by the X-ray absorber 60 when the phantom 6 is photographed, the phantom 6 can be detected in the X-ray photographed image 15. The X-ray absorber 60 may be any material as long as the amount of absorption of X-rays is large. In the first embodiment, a heavy metal is used as the X-ray absorber 60, for example. Heavy metals include, for example, gold, lead, tungsten and the like. Moreover, the raw material which forms the phantom 6 is not restricted to resin. When the phantom 6 is formed of a heavy metal or the like that absorbs X-rays, it is not necessary to include the X-ray absorber 60 inside. In addition, the X-ray absorber 60 may not be provided inside the phantom 6. For example, it may be provided on the surface of the phantom 6. The dimensions of the phantom 6 are known, and the position of the X-ray absorber 60 in the Y direction is known when installed on the top plate. Further, the X direction and the Z direction of the X-ray absorber 60 can be acquired from the X-ray image 15.

FIG. 7 is a schematic diagram showing an example of acquiring information on body movement of the subject T when there is no body movement in the subject T. As shown in FIG. FIG. 7A shows an X-ray captured image 15a captured by arranging the imaging system 7 at the first relative position (see FIG. 4). FIG. 7B shows an X-ray captured image 15b captured by arranging the imaging system 7 at the second relative position (see FIG. 4). FIG. 7C shows an X-ray captured image 15c captured by arranging the imaging system 7 at the third relative position (see FIG. 4). In the example shown in FIG. 7, a part of the subject T is illustrated as the subject T. Also, the internal structure 17 of the subject T is not shown for convenience.

In the first embodiment, the X-ray imaging apparatus 100 performs imaging while changing the relative position of the imaging system 7 with respect to the subject T. Therefore, in FIGS. 7A to 7C, the X-ray imaging image 15 is obtained. The positions of the phantom 6 and the subject T at the top change. Since the phantom 6 does not move at the time of imaging, the change (trend) in the appearance of the phantom 6 on the X-ray image 15 occurs only by the change in the imaging angle accompanying the movement of the imaging system 7 and can be grasped in advance. When there is no body movement in the subject T, the change in the appearance of the phantom 6 (trend) should coincide with the change in the appearance of the subject T (trend).

Therefore, the medical X-ray image processing apparatus 1 changes the relative position of the imaging system 7 to the subject T and changes the imaging angle (a change in the relative position of the imaging system 7) in the X-ray imaging image 15 It is configured to determine the presence or absence of body movement of the subject T by comparing the change in the way of appearance 6 (trend) with the change in the way of appearance of the subject T (trend).

The position information of the phantom 6 and the position information of the subject T may be acquired by any method. The position information acquisition unit 11 is configured to first acquire the feature point FP of the subject T when acquiring the position information of the subject T. The position information acquiring unit 11 is configured to acquire position information of the feature point FP of the subject T as the position information of the subject T. The characteristic point FP of the subject T may be acquired by any method. In the first embodiment, the position information acquiring unit 11 acquires the boundary of the subject T by edge processing, and uses the acquired boundary as the feature point FP of the object T.

In the example shown in FIG. 7B, the change in the appearance of the phantom 6 (trend) from the first relative position to the second relative position coincides with the change in the appearance of the subject T (trend). Further, in the example shown in FIG. 7C, the change in the appearance of the phantom 6 from the first relative position and the second relative position to the third relative position (trend) and the change in the appearance of the subject T (trend) And agree. Therefore, in the example illustrated in FIG. 7, the reconstructed image 16 determines that there is no body movement of the subject T. The phantom 6 and the subject T depicted by dotted lines in FIG. 7B and FIG. 7C indicate the phantom 6 and the subject T at the imaging positions up to that point.

FIG. 8 is a schematic diagram showing an example of acquiring information on body movement of the subject T when there is body movement in the subject T. As shown in FIG. Since FIG. 8 (A) and FIG. 8 (B) are schematic diagrams similar to FIG. 7 (A) and FIG. 7 (B), description is abbreviate | omitted. The example shown in FIG. 8C is an example in the case where the subject T has a body movement. That is, FIG. 8C shows the case where the subject T moves while shooting with the shooting system 7 moved to the third relative position after shooting with the shooting system 7 arranged at the second relative position. It is a schematic diagram which shows an example. The phantom 6 and the subject T depicted by solid lines in FIG. 8C represent the positions at which the phantom 6 and the subject T are actually depicted in the image captured at the third relative position. Further, the phantom 6 and the subject T depicted by dashed lines in FIG. 8C represent the positions of the phantom 6 and the subject T in the images captured at the first relative position and the second relative position. Further, the dashed-two dotted line in FIG. 8C represents the position of the subject T which is predicted to be drawn when there is no body movement in the subject T. The body movement information acquisition unit 12 is configured to acquire the body movement amount m of the subject T from the position of the subject T predicted to have no body movement and the position of the subject T actually depicted. Further, in the example shown in FIG. 8, a part of the subject T is illustrated as the subject T as in FIG. 7. Also, the internal structure 17 of the subject T is not shown for convenience.

(Determination process whether to exclude X-ray imaging image)
Next, with reference to FIG. 9, a process of determining whether or not to exclude the X-ray captured image 15 when the reconstructed image generation unit 13 according to the first embodiment generates the reconstructed image 16 will be described.

The number line 40 shown in FIG. 9 is a number line of the ratio r of the number of images in which body motion of the subject T is detected on the horizontal axis. As shown in FIG. 9, the ratio r of the number of images in which the body motion of the subject T is detected is the ratio of the number x of X-ray images 15 in which the body motion is detected to the total number of captured images N (x / N × 100). In the first embodiment, the reconstructed image generation unit 13 determines whether to exclude the X-ray imaging image 15 from the reconstruction based on the value of the ratio r of the number of images in which the body movement of the subject T is detected. Is configured. Specifically, as shown in FIG. 9, when the ratio r of the number of images in which body movement of the subject T is detected is less than the first threshold Th1, the reconstructed image generation unit 13 detects body movement. The X-ray image 15 is configured to be excluded. In addition, the reconstructed image generation unit 13 detects the body movement when the ratio r of the number of images in which the body movement of the subject T is detected is less than the first threshold Th1 and the second threshold Th2 or more. It is configured to reconfigure excluding 15. In addition, the reconstruction image generation unit 13 is configured not to perform reconstruction when the ratio r of the number of images in which body motion of the subject T is detected is equal to or more than the first threshold Th1. As shown in FIG. 9, the second threshold Th2 is a value smaller than the first threshold Th1. The first threshold Th1 is, for example, 10%. The second threshold Th2 is, for example, 5%.

(Method of generating reconstructed image)
Next, with reference to FIG. 10 and FIG. 11, the flow of processing in which the medical X-ray image processing apparatus 1 according to the first embodiment generates the reconstructed image 16 will be described.

In step S1, the control unit 4 arranges the imaging system 7 at a predetermined relative position via the imaging system position changing mechanism 5. Thereafter, in step S2, the X-ray image generation unit 14 generates an X-ray image 15.

Next, in step S3, the control unit 4 determines whether the photographing system 7 is arranged at all relative positions and photographed. If the photographing system 7 is placed at all relative positions and photographed, the process proceeds to step S4. If the photographing system 7 is arranged at all relative positions and photographing is not performed, the process returns to step S1.

In step S <b> 4, the position information acquisition unit 11 acquires position information of the phantom 6 and position information of the subject T that appear in the plurality of X-ray radiographed images 15. Thereafter, the process proceeds to step S5.

In step S5, the body motion information acquisition unit 12 acquires information on body motion of the subject T based on the position information of the phantom 6 and the position information of the subject T in each of the plurality of X-ray radiographed images 15. Thereafter, the process proceeds to step S6.

Next, in step S6, the reconstructed image generation unit 13 determines whether body movement of the subject T has been detected. If body movement of the subject T is detected, the process proceeds to step S7. If no body movement of the subject T is detected, the process proceeds to step S8.

In step S7, the reconstructed image generation unit 13 determines whether to exclude the X-ray captured image 15 from the reconstruction based on the information related to the body movement of the subject T. The detailed configuration for determining whether to exclude the X-ray image 15 from the reconstruction will be described later.

In step S8, the reconstruction image generation unit 13 generates a reconstruction image 16 in which a plurality of X-ray captured images 15 captured while changing the relative position of the imaging system 7 with respect to the subject T are reconstructed into one image.

Next, with reference to FIG. 11, a process of determining whether the reconstructed image generation unit 13 of the medical X-ray image processing apparatus 1 according to the first embodiment excludes the X-ray captured image 15 from reconstruction. The flow will be described.

In step S70, the reconstructed image generation unit 13 determines, based on the information on the body movement of the subject T, the number of X-ray radiographed images 15 in which the body movement of the subject T in the plurality of X-ray radiographed images 15 is detected. It is determined whether it is less than 1 threshold value Th1. If the degree of the number of X-ray images 15 in which the body movement of the subject T has been detected is less than the first threshold Th1, the process proceeds to step S71. If the degree of the number of X-ray images 15 in which the body movement of the subject T has been detected is equal to or greater than the first threshold value Th1, the process ends.

In step S71, the reconstructed image generation unit 13 determines whether the degree of the number of X-ray images 15 in which the body movement of the subject T has been detected is equal to or greater than a second threshold Th2. If the degree of the number of X-ray images 15 in which the body motion of the subject T is detected is less than the second threshold Th2, the process proceeds to step S8. If the degree of the number of X-ray images 15 in which the body motion of the subject T has been detected is equal to or greater than the second threshold Th2, the process proceeds to step S72.

In step S72, the reconstructed image generation unit 13 excludes the X-ray captured image 15 in which the body movement of the subject T is detected from the image used for reconstruction. Thereafter, the process proceeds to step S8.

For example, in the example shown in FIG. 8, body movement is detected in the subject T in the X-ray image 15c. Therefore, in the example shown in FIG. 8, the reconstructed image generation unit 13 excludes the X-ray image 15 c from the reconstruction to generate the reconstructed image 16. In the example shown in FIG. 7, the body movement of the subject T is not detected in the plurality of X-ray radiographed images 15, so the X-ray radiographed images 15a to 15c are used to generate the reconstructed image 16.

(Effect of the embodiment)
According to the embodiment of the present invention, the following effects can be obtained.

In the first embodiment, as described above, the medical X-ray image processing apparatus 1 includes the image acquisition unit 10 for acquiring a plurality of X-ray captured images 15 obtained by X-ray imaging, and a plurality of X-ray captured images 15. Based on the position information acquisition unit 11 for acquiring the position information of the phantom 6 and the position information of the subject T captured in the subject, the subject based on the position information of the phantom 6 and the position information of the subject T in each of the plurality of X-ray images 15 The body movement information acquisition unit 12 for acquiring information on the body movement of T, and the body movement of the subject T detected when the body movement of the subject T is detected in part of the plurality of X-ray images 15 Reconstructed image generation for generating a reconstructed image 16 in which a plurality of X-ray captured images 15 captured while changing the relative position of the imaging system 7 with respect to the subject T except for the radiographic image 15 are reconstructed into one image And 13As a result, even when body movement of the subject T is detected in part of the plurality of X-ray radiographed images 15, reconstruction can be performed excluding images in which body movement is detected. As a result, even if body motion of the subject T is detected, if there are the required number of images without body motion, the image without body motion of the subject T is reconstructed without using the image. Since it is possible to generate an image, it is possible to suppress degradation of the image quality of the reconstructed image 16 to be generated. In addition, since it is possible to generate the reconstructed image 16 by excluding the image in which the body movement of the subject T is detected, it is possible to suppress a decrease in the chance of performing the reconstruction. In addition, since it is possible to generate the reconstructed image 16 by excluding the image in which the body movement of the subject T is detected, it is possible to suppress the re-shooting as much as possible.

In the first embodiment, as described above, the reconstructed image generation unit 13 detects X-rays in which body motion of the subject T in the plurality of X-ray radiographed images 15 is detected based on the information on body motion of the subject T. When the degree of the number of captured images 15 is less than the first threshold Th1, the X-ray captured image 15 in which the body movement of the subject T is detected is excluded. Thereby, it becomes possible to exclude the image in which the body movement of the subject T is detected from the reconstruction according to the degree of the number of images in which the body movement of the subject T is detected. As a result, since there is a trade-off between the number of images used for reconstruction and the image quality of the generated reconstructed image 16, the reconstructed image 16 can be generated without excessively degrading the image quality.

In the first embodiment, as described above, the reconstructed image generation unit 13 determines that the number x of X-ray images 15 in which body motion of the subject T in the plurality of X-ray images 15 is detected is When it is less than the second threshold Th2 smaller than the one threshold Th1, the reconstructed image 16 is generated without excluding the X-ray imaging image 15 in which the body movement of the subject T is detected. Here, depending on the number of images in which the body movement of the subject T is detected, the image quality of the reconstructed image 16 obtained may not be substantially affected even when reconstructed as it is. That is, when the number of images in which body motion of the subject in the total captured image is detected is equal to or less than a predetermined number, the image quality of the reconstructed image 16 may not substantially deteriorate. Therefore, even if there is an image in which the body movement of the subject T is detected, the image can be reconstructed without being excluded according to the number x of images in which the body movement is detected. As a result, the number of X-ray images which can be used for the reconstructed image 16 can be increased, so that deterioration of the image quality of the reconstructed image 16 can be suppressed.

In the first embodiment, as described above, the reconstructed image generation unit 13 determines that the number x of X-ray images 15 in which body motion of the subject T in the plurality of X-ray images 15 is detected is If larger than one threshold value Th1, the reconstructed image 16 is not generated. Thus, when the degree of the number x of the X-ray images 15 in which the body movement of the subject T is detected is larger than the first threshold value Th1, it is possible to suppress the reconstruction. As a result, when it is predicted that the minimum necessary image quality can not be obtained even if reconstruction is performed excluding images in which body motion is detected, generation of a low-quality reconstructed image 16 is suppressed. can do.

Further, in the first embodiment, as described above, the reconstructed image generation unit 13 sets the ratio of the number of X-ray captured images 15 in which the body motion of the subject T in the plurality of X-ray captured images 15 is detected. When it is less than the threshold Th1, the reconstructed image 16 is generated by excluding the X-ray image 15 in which the body movement of the subject T is detected. Thereby, the influence of the exclusion on the image quality can be appropriately evaluated by the ratio of the exclusion number to the total number. As a result, it is possible to properly determine whether or not to perform the reconfiguration.

In the first embodiment, as described above, the X-ray imaging apparatus 100 detects by the X-ray source 2, the detector 3 that detects X-rays emitted from the X-ray source 2, and the detector 3. Medical X-ray image processing apparatus 1 for generating an X-ray image 15 from the intensity distribution of X-rays, and an imaging system position changing mechanism for changing the relative position of an imaging system 7 consisting of an X-ray source 2 and a detector 3 5 and the medical X-ray image processing apparatus 1 is configured to acquire position information of the phantom 6 and position information of the subject T captured in a plurality of X-ray radiographed images 15, medical X-ray image processing The apparatus 1 is configured to acquire information related to the body movement of the subject T based on the position information of the phantom 6 and the position information of the subject T in the plurality of X-ray radiographed images 15, and the medical X-ray image processing apparatus 1 is that of multiple X-ray images 15 The medical X-ray image processing apparatus 1 is configured to determine the presence or absence of body movement of the subject T in the case where the body movement of the subject T is detected in a part of the plurality of X-ray radiographed images 15. A plurality of X-ray images 15 captured while changing the relative position of the imaging system 7 with respect to the subject T except for the X-ray image 15 in which the body motion of the subject T is detected are reconstructed into one image. It is configured to generate a reconstructed image 16. As a result, even when body movement of the subject T is detected in part of the plurality of X-ray radiographed images 15, reconstruction can be performed excluding images in which body movement is detected. As a result, even if body motion of the subject T is detected, if there are the required number of images without body motion, the image without body motion of the subject T is reconstructed without using the image. Since the image 16 can be generated, deterioration in the image quality of the generated reconstructed image 16 can be suppressed. In addition, since it is possible to generate the reconstructed image 16 by excluding the image in which the body movement of the subject T is detected, it is possible to suppress a decrease in the chance of performing the reconstruction. In addition, since it is possible to generate the reconstructed image 16 by excluding the image in which the body movement of the subject T is detected, it is possible to suppress the re-shooting as much as possible.

Second Embodiment
Next, a medical X-ray image processing apparatus 20 according to a second embodiment of the present invention will be described with reference to FIGS. 1, 2, 10, 12 and 13. FIG. When the degree of the number of X-ray images 15 in which the body movement of the subject T is detected is less than the first threshold Th1, the first X-ray image 15 in which the body movement of the subject T is detected is excluded from the reconstruction Unlike the embodiment, in the second embodiment, when the medical X-ray image processing apparatus 20 determines that the number of X-ray images 15 in which the body movement of the subject T is detected is less than the first threshold Th1, The position of the subject T in the X-ray image 15 is corrected based on the body movement amount m of T, and it is configured to switch whether or not to use for reconstruction. The same reference numerals are given to the same components as those in the first embodiment, and the description will be omitted.

The reconstructed image generation unit 13 according to the second embodiment performs at least the X-ray captured image 15 of the X-ray captured image 15 based on the body movement amount m of the subject T in the X-ray captured image 15. It is configured to correct the position and switch whether or not to use for reconstruction. Specifically, the reconstructed image generation unit 13 determines that the body movement amount m of the subject T in the X-ray captured image 15 in which the body movement of the subject T in the plurality of X-ray captured images 15 is detected is a third threshold Th3 (FIG. Reference) In the above case, the position of the subject T in the X-ray image 15 in which the body motion of the subject T is detected is excluded from the reconstruction without being corrected. In addition, the reconstructed image generation unit 13 determines that the body movement amount m of the subject T in the X-ray captured image 15 in which the body movement of the subject T in the plurality of X-ray captured images 15 is detected is less than the third threshold Th3, the third threshold Th3. The fourth embodiment is configured to generate the reconstructed image 16 by correcting the position of the subject T in the X-ray captured image 15 in which the body movement of the subject T is detected, in the case of the fourth threshold Th4 (see FIG. 12) or smaller. ing. In the second embodiment, the reconstructed image generation unit 13 performs position correction when there is body movement that can be position corrected in the X-ray image 15 among body movements of the subject T. Is configured as. That is, the reconstructed image generation unit 13 is configured to perform position correction when the body movement of the subject T is parallel movement in the XZ plane and rotational movement around the Y axis direction in the XZ plane. There is. In addition, the reconstructed image generation unit 13 is configured to exclude from the image used for the reconstruction, when the body movement of the subject T can not correct the position of the subject T in the X-ray image 15. It is done.

In the second embodiment, the reconstructed image generation unit 13 detects the body movement of the subject T if the body movement amount m of the subject T in at least the excluded X-ray imaging image 15 is less than the fourth threshold Th4. It is configured to be used for generation of the reconstructed image 16 without correcting the position of the subject T in the line-photographed image 15.

The number line 40 shown in FIG. 12 is a number line of the ratio r of the number of images in which body motion of the subject T is detected on the horizontal axis. Further, in the number line 41 shown in FIG. 12, the horizontal axis is a number line of the body movement amount m of the subject T. As shown in FIG. 12, in the second embodiment, the reconstructed image generation unit 13 determines that the ratio r of the number of X-ray images 15 in which body movement is detected is greater than or equal to a first threshold Th1 and less than a second threshold Th2. In this case, the handling of the X-ray image 15 is determined based on the amount of body movement m of the subject T. Specifically, when the body movement amount m of the subject T is less than the third threshold value Th3, the reconstruction image generation unit 13 is configured to use the X-ray imaging image 15 as it is for reconstruction. In addition, when the body movement amount m of the subject T is equal to or larger than the third threshold Th3 and smaller than the fourth threshold Th4, the reconstructed image generation unit 13 performs position correction of the subject T in the image in which the body movement of the subject T is detected. Is configured. In addition, the reconstructed image generation unit 13 is configured to exclude the image in which the body movement of the subject T is detected from the reconstruction when the body movement amount m of the subject T is equal to or more than the fourth threshold Th4. The third threshold Th3 is, for example, 5 mm. The fourth threshold Th4 is, for example, 1 cm.

Next, with reference to FIG. 13, the handling process of the X-ray imaging image 15 when the medical X-ray image processing apparatus 20 in the second embodiment generates the reconstructed image 16 will be described. The same processing as that of the first embodiment is given the same reference numeral, and the description is omitted.

In step S700, the reconstructed image generation unit 13 determines whether the amount of movement m of the subject T is equal to or greater than a third threshold Th3. If the amount of movement m of the subject T is equal to or greater than the third threshold Th3, the process proceeds to step S701. If the body movement amount m of the subject T is smaller than the third threshold Th3, the process proceeds to step S702.

In step S701, the reconstruction image generation unit 13 excludes the X-ray captured image 15 in which the body movement of the subject T is detected from the image used for reconstruction. Thereafter, the process proceeds to step S704.

In step S702, the reconstructed image generation unit 13 determines whether the amount of movement m of the subject T is equal to or greater than a fourth threshold Th4. If the amount of movement m of the subject T is equal to or greater than the fourth threshold Th4, the process proceeds to step S703. If the body movement amount m of the subject T is less than the fourth threshold Th4, the process proceeds to step S704.

In step S703, the reconstructed image generation unit 13 corrects the position of the subject T in the X-ray captured image 15. Thereafter, the process proceeds to step S704.

In step S704, the reconstructed image generation unit 13 determines whether or not the amount of body movement m of all the X-ray captured images 15 in which the body movement of the subject T has been detected. If it is determined that the amount of movement m of all the X-ray images 15 in which the movement of the subject T has been detected, the process proceeds to step S9. When the body movement amount m of all the X-ray imaging images 15 in which the body movement of the subject T has been detected is not determined, the process returns to step S701.

The remaining structure of the second embodiment is similar to that of the aforementioned first embodiment.

(Effect of the second embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, as described above, the information related to the body movement includes the body movement amount m of the subject T, and the reconstructed image generation unit 13 generates an X-ray image for the X-ray image 15 excluded at least. The position of the subject T in the X-ray image 15 is corrected based on the body movement amount m of the subject T at 15 and it is switched whether or not to use for reconstruction. As a result, even if an image in which the body movement of the subject T is detected, if the position correction can be performed based on the body movement amount m of the subject T, the number of images used for reconstruction is increased. be able to. Therefore, the image quality of the image obtained by the reconstruction can be improved as compared with the case where the image in which the body movement of the subject T is detected is excluded from the reconstruction without position correction. In addition, when it is not possible to perform position correction, it can be excluded from the image used for reconstruction, so that deterioration in the image quality of the reconstructed image 16 can be suppressed.

In the second embodiment, as described above, the reconstructed image generation unit 13 determines the amount of movement m of the subject T in the X-ray captured image 15 in which the body movement of the object T in the plurality of X-ray captured images 15 is detected. If the third threshold value Th3 or more, the position of the subject T in the X-ray image 15 in which the body movement of the subject T is detected is excluded from the reconstruction without correcting the position of the subject T. Thus, when the amount of body movement m of the subject T is equal to or greater than the third threshold Th3, the X-ray image 15 can be excluded from the reconstruction. As a result, it is possible to easily suppress that the X-ray image 15 which can not be subjected to position correction is used for reconstruction.

In the second embodiment, as described above, the reconstructed image generation unit 13 determines the amount of movement m of the subject T in the X-ray captured image 15 in which the body movement of the object T in the plurality of X-ray captured images 15 is detected. Is smaller than the third threshold Th3 and larger than the fourth threshold Th4 smaller than the third threshold Th3, the position of the subject T in the X-ray image 15 in which the body movement of the subject T is detected is corrected and the reconstructed image 16 is It is configured to generate. Thereby, even in the image in which the body movement of the subject T is detected, if the body movement amount m is within the range of the predetermined threshold, the position correction can be performed and used for the reconstruction. As a result, since it is possible to increase the number of images used for reconstruction, the image quality of the reconstructed image 16 can be improved.

Further, in the second embodiment, as described above, the body movement of the subject T is performed when the body movement amount m of the subject T in at least the excluded X-ray imaging image 15 is less than the fourth threshold Th4 as described above. It is configured to be used for generation of the reconstructed image 16 without correcting the position of the subject T in the X-ray image 15 in which X is detected. Thereby, for example, when the amount of body movement m is small to such an extent that there is no need to perform position correction, it can be used for generation of the reconstructed image 16 without position correction. As a result, generation of the reconstructed image 16 can be simplified as compared with the case where position correction is performed regardless of the extent of the body movement amount m.

The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

Third Embodiment
Next, the configuration of a medical X-ray image processing apparatus 30 according to a third embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 14 to 17. When the degree of the number of X-ray images 15 in which the body movement of the subject T is detected is less than the first threshold Th1, the first X-ray image 15 in which the body movement of the subject T is detected is excluded from the reconstruction Unlike the embodiment, in the third embodiment, the total number of radiographed images at the timing when the X-ray imaging image 15 in which the body movement of the subject T is detected is captured in the plurality of X-ray imaging images 15 captured continuously The X-ray imaging apparatus 100 further includes an imaging switching unit 31 that switches whether to interrupt or continue imaging in the X-ray imaging apparatus 100 based on the imaging order with respect to. The same reference numerals are given to the same components as those in the first embodiment, and the description will be omitted. The imaging order with respect to the total number of radiographed images at the timing at which the X-ray imaging image 15 at which the body movement of the subject T is detected is taken is the imaging at which the X-ray imaging image 15 in which It is a ratio to the total number of shots in order.

As shown in FIG. 14, the medical X-ray image processing apparatus 30 according to the third embodiment includes the X-ray images 15 in which body motion of the subject T is detected in the plurality of X-ray images 15 captured continuously. The imaging switching unit 31 is further provided to switch whether to interrupt or continue imaging in the X-ray imaging apparatus 100 based on the imaging order with respect to the total imaging number at the timing when imaging is performed. Further, in the third embodiment, when the body movement of the subject T is detected in a part of the plurality of X-ray photographed images 15, the radiography switching unit 31 shoots up to the imaging position at which the body movement of the subject T is detected. The system 7 is moved to switch whether or not to perform re-shooting.

(Judging whether to interrupt or continue shooting)
Next, with reference to FIG. 15, a process of determining whether the imaging switching unit 31 in the third embodiment interrupts or continues imaging will be described.

In the number line 42 shown in FIG. 15, the horizontal axis is a number line of time t. Further, the number line 43 shown in FIG. 15 is a number line of the shooting order tg with respect to the total number N of shots at the timing when the body movement of the subject T is detected on the horizontal axis. The shooting order tg with respect to the total number of shots N at the timing when the body movement of the subject T is detected is a ratio (n0 / N × 100) to the total shooting number N of the shooting order n0 where the body movement of the subject T is detected. is there. Further, in the number line 44 shown in FIG.

As shown in FIG. 15, the imaging switching unit 31 is configured to interrupt imaging when the imaging order tg with respect to the total number of imaging N at the timing when the body movement of the subject T is detected is less than the fifth threshold Th5. There is. In addition, when the shooting order tg with respect to the total number of shots N at the timing at which the body motion of the subject T is detected is the fifth threshold Th5 or more, the shooting switching unit 31 interrupts shooting based on the body movement amount m of the subject T It is configured to determine whether to continue or not. Specifically, the imaging switching unit 31 is configured to continue imaging when the amount of movement m of the subject T is less than the sixth threshold Th6. In addition, the imaging switching unit 31 is configured to continue imaging when the amount of movement m of the subject T is equal to or greater than the sixth threshold Th6. In the third embodiment, as a method of performing re-imaging, the X-ray imaging apparatus 100 interrupts imaging when the body movement amount m of the subject T in the X-ray imaging image 15 is equal to or greater than a sixth threshold Th6. Move the shooting system 7 to the shooting position where body movement of T has been confirmed and resume shooting, or shoot without interruption and the position where body movement of the subject T is confirmed after shooting is completed It is configured to take a picture. In the third embodiment, as the body movement amount m, not only parallel movement in the XZ plane in the X-ray image 15 and rotational movement around the Y axis direction in the XZ plane, rotational movement around the X axis and Also includes rotational movement around the Z axis. The fifth threshold Th5 is, for example, 70%. The sixth threshold Th6 is, for example, 5 cm. The sixth threshold Th6 is a value larger than the fourth threshold Th4.

Next, with reference to FIGS. 16 and 17, the flow of processing for determining whether the imaging switching unit 31 in the third embodiment interrupts or continues imaging will be described. The same processing as that of the first embodiment is given the same reference numeral, and the description is omitted.

In steps S1 to S3, the medical X-ray image processing apparatus 30 generates an X-ray image 15 captured by arranging the imaging system 7 at a predetermined relative position.

Next, in step S30, positional information of the phantom 6 and the subject T appearing in the generated X-ray image 15 is acquired. Thereafter, when the body movement of the subject T is detected in step S5 and step S6, the process proceeds to step S9.

In step S9, the imaging switching unit 31 interrupts the imaging in the X-ray imaging apparatus 100 based on the imaging order with respect to the total number of imaging at the timing when the X-ray imaging image 15 at which the body motion of the subject T is detected is imaged. Make a decision to switch on or off. Details of the determination to switch whether to interrupt or continue imaging in the X-ray imaging apparatus 100 will be described later.

Thereafter, the process proceeds to step S3, step S7 and step S8, and the process ends.

Next, with reference to FIG. 16, the determination as to whether the imaging switching unit 31 in the third embodiment switches between interruption or continuation of imaging in the X-ray imaging apparatus 100 will be described.

In step S90, the imaging switching unit 31 determines whether the imaging order with respect to the total number of imagings at the timing when the X-ray imaging image 15 at which the body motion of the subject T is detected is captured is less than the fifth threshold Th5. Do. If the imaging order with respect to the total number of imagings at the timing when the X-ray imaging image 15 is acquired is equal to or higher than the fifth threshold Th5, the process ends. That is, shooting is interrupted. If the imaging order with respect to the total number of imaging at the timing when the X-ray imaging image 15 is acquired is less than the fifth threshold Th5, the process proceeds to step S91.

In step S91, the reconstructed image generation unit 13 determines whether the amount m of body movement of the subject T in the X-ray image 15 is equal to or greater than a sixth threshold Th6. If the body movement amount m of the subject T in the X-ray image 15 is equal to or larger than the sixth threshold Th6, the process proceeds to step S92. If the amount of movement m of the subject T in the X-ray image 15 is less than the sixth threshold Th6, the process proceeds to step S3.

In step S92, the imaging switching unit 31 moves the imaging system 7 to the imaging position at which the body movement of the subject T is detected. Thereafter, the process proceeds to step S93. In step S93, the X-ray imaging apparatus 100 resumes imaging of the subject T.

The remaining structure of the third embodiment is similar to that of the aforementioned first embodiment.

(Effect of the third embodiment)
In the third embodiment, the following effects can be obtained.

In the third embodiment, as described above, with respect to the total number of radiographed images at the timing when the X-ray radiographed image 15 in which the body movement of the subject T is detected in the plurality of X-ray radiographed images 15 radiographed continuously. The imaging switching unit 31 is further provided to switch whether to interrupt or continue imaging in the X-ray imaging apparatus 100 based on the imaging order. Here, in the case where shooting is usually performed continuously, once movement occurs, body movement will continue thereafter, so when body movement of the subject T is detected at a timing when the photographing order is early by the above configuration , Can interrupt the shooting. As a result, the exposure amount of the subject T can be reduced. In addition, when body movement of the subject T is detected at a timing when the photographing order is late after most of the images are taken, the photographing can be continued without interruption. As a result, for example, as compared with the case where imaging is performed again, it is unnecessary to recapture a place where the body motion of the subject T is not detected, and therefore the exposure dose can be reduced.

In the third embodiment, as described above, when the body movement of the subject T is detected in part of the plurality of X-ray radiographed images 15, the imaging switching unit 31 detects the body movement of the subject T. It is configured to move the imaging system 7 to the imaging position and switch whether or not to perform imaging again. As a result, when re-shooting is performed, it is possible to perform re-shooting only at a place that needs re-shooting, so unnecessary exposure can be suppressed. Moreover, since it becomes possible to suppress performing unnecessary imaging | photography, when not performing imaging | photography again, unnecessary exposure can be suppressed.

(Modification)
It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the description of the embodiments described above but by the claims, and further includes all modifications (modifications) within the meaning and scope equivalent to the claims.

For example, although the medical X-ray image processing apparatus 1 shows the example used for the reconstruction of the X-ray imaging image 15 in tomosynthesis in the said embodiment, this invention is not limited to this. It may be used to reconstruct images other than tomosynthesis. For example, it may be used for reconstruction of an image captured by long-length imaging, tomographic imaging (CT imaging), dual energy subtraction method or the like.

Further, in the above-described embodiment, an example is shown in which shooting is performed while moving the shooting system 7 in the longitudinal direction of the subject T, but the present invention is not limited to this. For example, shooting may be performed while moving the shooting system 7 in the lateral direction of the subject T.

In the first embodiment, the medical X-ray image processing apparatus 1 performs imaging at all relative positions, and then determines the presence or absence of body movement of the plurality of X-ray imaging images 15, and body movement is detected. Although the example which excludes the radiographic image 15 from reconstruction is shown, the present invention is not limited to this. For example, as shown in FIG. 18, the medical X-ray image processing apparatus 1 may be configured to determine the presence or absence of body movement of the subject T each time imaging is performed at each relative position. In addition, as shown in FIG. 19, the reconstructed image generation unit 13 may be configured to perform position correction when the amount of movement m of the subject T is equal to or greater than the fourth threshold Th4 and smaller than the third threshold Th3. . According to this configuration, the medical X-ray image processing apparatus 1 performs position correction when the body movement amount m of the subject T in the X-ray image 15 is equal to or greater than the fourth threshold Th4 and smaller than the third threshold Th3 to reconstruct It can be used for As a result, it is possible to increase the number of X-ray images 15 that can be used for reconstruction, thereby further increasing the chance of performing reconstruction.

Moreover, in the said embodiment, although the phantom 6 showed the structure containing one X-ray absorber 60, this invention is not limited to this. The phantom 6 may include one or more X-ray absorbers 60. For example, the central portion of the phantom 6 may be configured to include two X-ray absorbers 60 whose positions in the Y direction are different. With this configuration, as compared to the case where one X-ray absorber 60 is included, the change (trend) in the appearance of the X-ray absorber 60 with the change in the imaging angle due to the movement of the imaging system 7 is clearer Can be grasped. As a result, the presence or absence of body movement of the subject T can be determined more accurately.

Moreover, although the example in which the medical X-ray image processing apparatus 1 is provided in the X-ray imaging apparatus 100 has been shown in the above embodiment, the present invention is not limited to this. For example, the medical X-ray image processing apparatus 1 and the X-ray imaging apparatus 100 may be separately provided. In such a case, the medical X-ray image processing apparatus 1 may be configured to obtain a plurality of X-ray radiographed images 15 generated by the X-ray image radiographing apparatus 100 and perform reconstruction.

In the above embodiment, the medical X-ray image processing apparatus 1 is provided separately from the control unit 4 of the X-ray imaging apparatus 100. However, the present invention is not limited to this. For example, the medical X-ray image processing apparatus 1 and the control unit 4 may be integrally provided. That is, the control unit 4 of the X-ray imaging apparatus 100 may be configured to have the function of the medical X-ray image processing apparatus 1.

In the above embodiment, an example is shown in which the reconstructed image generation unit 13 generates the reconstructed image 16 using two or three X-ray images 15, but the present invention is limited to this. Absent. As long as the reconstructed image 16 can be generated, the number of X-ray images 15 used may be any number.

In the above embodiment, the imaging system position changing mechanism 5 moves and rotates the X-ray source 2 to change the relative position of the imaging system 7 to the subject T. However, the present invention is not limited thereto. It is not limited to. As long as the relative position of the imaging system 7 to the subject T can be changed, either the X-ray source 2 or the detector 3 may be moved. The relative position of the imaging system 7 to the subject T may be changed by moving both the X-ray source 2 and the detector 3.

In the above embodiment, an example is shown in which the position information acquisition unit 11 acquires coordinate values in the X-ray image 15 as position information of the phantom 6 and the subject T, but the present invention is not limited to this. For example, the position information acquisition unit 11 may be configured to acquire, as position information, a vector value having a distance and a direction from the reference with a certain point of the X-ray captured image 15 as a reference.

Furthermore, although the medical X-ray image processing apparatus 1 includes the X-ray image generation unit 14 in the above embodiment, the present invention is not limited to this. For example, the X-ray image generation unit 14 may be provided separately from the medical X-ray image processing apparatus 1. In that case, the image acquisition unit 10 of the medical X-ray image processing apparatus 1 is configured to acquire, for example, the X-ray imaging image 15 generated in advance by the X-ray imaging image generation unit 14 provided in the detector 3 or the like. It should be done.

1, 20, 30 medical X-ray image processing apparatus (image processing unit)
Reference Signs List 2 X-ray source 3 detector 5 imaging system position changing mechanism 6 phantom 7 imaging system 10 image acquisition unit 11 position information acquisition unit 12 physical motion information acquisition unit 13 reconstructed

image generation unit

15, 15a, 15b, 15c X-ray imaging image 16 reconstruction image 31 imaging switching unit 100 X-ray imaging apparatus m body movement amount T subject Th1 first threshold Th2 second threshold Th3 third threshold Th4 fourth threshold

Claims

An image acquisition unit that acquires a plurality of X-ray imaging images obtained by X-ray imaging;
A position information acquisition unit that acquires position information of phantoms and position information of an object captured in a plurality of X-ray radiographed images;
A body movement information acquisition unit for acquiring information on body movement of a subject based on position information of the phantom and position information of the subject in each of a plurality of X-ray radiographed images;
When the body movement of the subject is detected in part of the plurality of X-ray radiographed images, the X-ray radiographed image in which the body movement of the subject is detected is excluded and the relative position of the imaging system to the subject is changed. A medical X-ray image processing apparatus, comprising: a reconstructed image generation unit configured to generate a reconstructed image in which a plurality of the X-ray radiographed images are reconstructed into one image.
When the number of X-ray imaging images in which body movement of a subject in a plurality of X-ray imaging images is detected is less than a first threshold based on the information on the body movement of the subject, the reconstructed image generation unit The medical X-ray image processing apparatus according to claim 1, wherein the X-ray imaging image in which a body movement of a subject is detected is excluded.
When the degree of the number of X-ray captured images in which body movement of the subject in the plurality of X-ray captured images is detected is less than a second threshold smaller than the first threshold, the reconstructed image generation unit may The medical X-ray image processing apparatus according to claim 2, configured to generate the reconstructed image without excluding the X-ray imaging image in which a body movement of a subject is detected.
The reconstruction image generation unit does not generate the reconstruction image when the degree of the number of the X-ray imaging images in which the body movement of the subject in the plurality of X-ray imaging images is detected is larger than the first threshold. The medical X-ray imaging apparatus according to claim 2 or 3, which is configured as follows.
The reconstructed image generation unit detects body movement of the subject when the ratio of the number of the radiographed images in which body movement of the subject among the plurality of X-ray radiographed images is detected is less than the first threshold. The medical X-ray image processing apparatus according to claim 4, configured to generate the reconstructed image by excluding the X-ray image.
The information related to the body movement includes the body movement amount of the subject,
The reconstructed image generation unit corrects the position of the subject in the X-ray captured image by correcting the position of the subject in the X-ray captured image based on the amount of movement of the subject in the X-ray captured image. The medical X-ray imaging apparatus according to claim 4 or 5, which is configured to switch whether or not to use it.
The reconstructed image generation unit detects body movement of the subject when the body movement amount of the subject in the X-ray photographed image in which body movement of the subject in the plurality of X-ray photographed images is detected is equal to or more than a third threshold. The medical X-ray image processing apparatus according to claim 6, wherein the position of the subject in the X-ray image is excluded from reconstruction without correcting the position of the subject.
The reconstructed image generation unit is configured such that the amount of body movement of the subject in the X-ray photographed image in which the body movement of the subject in the plurality of X-ray photographed images is detected is smaller than the third threshold and smaller than the third threshold The medical X-ray according to claim 7, wherein when the threshold is four or more, the position of the subject in the X-ray imaging image in which body movement of the subject is detected is corrected to generate the reconstructed image. Image processing device.
The reconstructed image generation unit corrects the position of the subject in the X-ray photographed image in which the body movement of the subject is detected, when the body movement amount of the subject in at least the excluded X-ray photographed image is smaller than the fourth threshold. The medical X-ray imaging apparatus according to claim 8, configured to be used for generating the reconstructed image without performing processing.
The imaging in the X-ray imaging apparatus is performed based on the imaging sequence with respect to the total number of imagings at the timing when the X-ray imaging image at which the body movement of the subject is detected in the plurality of X-ray imaging images captured continuously The medical X-ray image processing apparatus according to claim 9, further comprising: an imaging switching unit that switches whether to interrupt or to continue.
The imaging switching unit moves the imaging system to the imaging position at which the body movement of the subject is detected, and rephotographs when the body movement of the subject is detected in a part of the plurality of X-ray imaging images. The medical X-ray image processing apparatus according to claim 10, which is configured to switch whether or not to.
An x-ray source,
A detector for detecting X-rays emitted from the X-ray source;
An image processing unit that generates an X-ray image from the intensity distribution of X-rays detected by the detector;
An imaging system position changing mechanism for changing a relative position of an imaging system including the X-ray source and the detector;
The image processing unit is configured to acquire position information of a phantom and position information of an object appearing in a plurality of the X-ray images.
The image processing unit is configured to acquire information on body movement of a subject based on position information of the phantom and position information of the subject in the plurality of X-ray radiographed images,
The image processing unit is configured to determine the presence or absence of body movement of the subject in each of the plurality of X-ray imaging images,
The image processing unit excludes the X-ray photographed image in which the body movement of the subject is detected, when the body movement of the subject is detected in a part of the plurality of X-ray photographed images, An X-ray imaging apparatus, which is configured to generate a reconstructed image in which a plurality of the X-ray radiographed images are reconstructed into one image while changing a relative position with respect to a subject.