X-ray imaging apparatus and imaging position correction method

Abstract

An X-ray imaging apparatus and an imaging position correction method are provided. The X-ray imaging apparatus includes an X-ray irradiation unit, an X-ray detection unit, and a correction information acquisition unit. The correction information acquisition unit determines the outer edges of multiple predetermined portions of an object being imaged in an X-ray image, and acquires position correction information for correcting the relative position of the X-ray irradiation unit relative to the object being imaged in the object. The position correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation unit relative to the object being imaged in the object so that an X-ray image can be captured showing the positional relationship between the outer edges of the multiple predetermined portions.

Description

Technical Field

[0001] This invention relates to an X-ray imaging apparatus and a method for correcting imaging position. Background Technology

[0002] Previously, an X-ray imaging device was known. Such a device was disclosed, for example, in Japanese Patent Application Publication No. 2014-117368.

[0003] Japanese Patent Application Publication No. 2014-117368 discloses an X-ray imaging apparatus comprising: an X-ray source for irradiating X-rays; an X-ray detector for detecting X-rays; and a display device for displaying a composite motion image obtained by combining an optical motion image and a guide image. With this X-ray imaging apparatus, the operator instructs the patient to change the imaging position while observing the composite motion image displayed on the display device in the control room. Conversely, the patient changes their own imaging position while observing the composite motion image displayed on the display device in the imaging room.

[0004] In the field of orthopedic surgery, X-ray imaging is a challenging procedure, even for experienced radiologists. For example, when taking lateral knee X-rays to diagnose conditions such as osteochondritis dissecans and osteoarthritis of the knee, it is necessary to adjust the imaging position to capture an X-ray image where the outer edges of the medial femoral condyle (the midline side of the femur on the knee side) overlap with the outer edges of the lateral femoral condyle (the side of the femur on the knee side opposite to the midline side) for accurate diagnosis. However, due to individual differences in bone shape and muscle attachment in the leg, even experienced radiologists find it very difficult to adjust the imaging position according to the patient's appearance and capture an X-ray image where the outer edges of the medial and lateral femoral condyles overlap. Therefore, to capture an X-ray image that accurately reflects this overlap, the imaging position needs to be corrected after the X-ray image is taken. Furthermore, obtaining accurate diagnostic X-ray images requires repeated X-ray imaging and positioning corrections, which increases the radiation dose to the subject and the imaging time. Therefore, it is desirable to obtain accurate diagnostic X-ray images while minimizing the increase in radiation dose and imaging time. Summary of the Invention

[0005] The present invention was made to solve the problems described above. One object of the present invention is to provide an X-ray imaging apparatus and imaging position correction method that can acquire accurate diagnostic X-ray images while suppressing the increase in radiation dose and imaging time.

[0006] An X-ray imaging apparatus according to a first aspect of the present invention comprises: an X-ray irradiation unit that irradiates an examination subject with X-rays; an X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the examination subject; and a correction information acquisition unit that determines the outer edges of each of a plurality of predetermined portions of a radiographic object of the examination subject in an X-ray image captured based on the detection signal of the X-ray detection unit, and acquires position correction information for correcting the relative position of the X-ray irradiation unit relative to the radiographic object of the examination subject based on the determined positional relationship between the outer edges of the plurality of predetermined portions, wherein the position correction information includes a relative movement direction and a relative movement amount for correcting the relative position of the X-ray irradiation unit relative to the radiographic object of the examination subject to a position that can capture an X-ray image in which the positional relationship between the outer edges of the plurality of predetermined portions is reflected by a predetermined positional relationship.

[0007] The second aspect of the present invention provides a method for correcting the imaging position, comprising the following steps: an irradiation step, irradiating an object with X-rays from an X-ray irradiation unit; a detection step, detecting X-rays that have passed through the object; and a correction information acquisition step, determining the outer edges of each of a plurality of predetermined portions of an object being photographed in an X-ray image captured based on the detection of X-rays in the detection step, and acquiring position correction information for correcting the relative position of the X-ray irradiation unit relative to the object being photographed in the object, based on the determined positional relationship between the outer edges of the plurality of predetermined portions, wherein the position correction information includes a relative movement direction and a relative movement amount for correcting the relative position of the X-ray irradiation unit relative to the object being photographed in the object so that an X-ray image can be captured showing the positional relationship between the outer edges of the plurality of predetermined portions in a predetermined positional relationship.

[0008] In the X-ray imaging apparatus of the first aspect and the imaging position correction method of the second aspect of the present invention, the outer edges of each of a plurality of predetermined portions of an object to be imaged on an X-ray subject are determined, and position correction information for correcting the relative position of the X-ray irradiation unit with respect to the object to be imaged on the subject is obtained based on the positional relationship between the determined outer edges of the plurality of predetermined portions. Furthermore, the position correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation unit with respect to the object to be imaged on the subject so that an X-ray image can be captured showing the positional relationship between the outer edges of the plurality of predetermined portions in a predetermined positional relationship. Thus, by obtaining position correction information including the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation unit with respect to the object to be imaged on the subject, such as bone or artificial joint, so that an X-ray image can be captured showing the positional relationship between the outer edges of the plurality of predetermined portions in a predetermined positional relationship, the relative movement direction and relative movement amount required for correction can be notified using the obtained position correction information, allowing users such as radiologists to perform high-precision correction of the imaging position based on the notification result. As a result, the number of times X-ray image imaging and imaging position correction are repeatedly performed can be reduced. Therefore, an X-ray imaging apparatus and imaging position correction method can be provided that can acquire accurate diagnostic X-ray images while suppressing increases in radiation dose and imaging time. Furthermore, by controlling the relative position of the X-ray irradiation unit using the acquired position correction information, the relative position of the X-ray irradiation unit with respect to the subject, such as bone or artificial joints, can be precisely corrected to a position that captures an X-ray image showing the positional relationship between the outer edges of multiple specified parts in a position suitable for diagnosis. As a result, the number of times X-ray image capture and imaging position correction are repeatedly performed can be reduced. Thus, an X-ray imaging apparatus and imaging position correction method can be provided that can acquire accurate diagnostic X-ray images while suppressing increases in radiation dose and imaging time. Attached Figure Description

[0009] Figure 1 This is a schematic diagram showing the overall structure of the X-ray imaging apparatus according to the first embodiment of the present invention.

[0010] Figure 2 This is a block diagram illustrating the structure of an X-ray imaging apparatus according to a first embodiment of the present invention.

[0011] Figure 3 This is an example of a subject lying down when photographing the side of the knee joint.

[0012] Figure 4 This is a diagram showing the structure of the bones around the joint of the right knee as seen from the rear.

[0013] Figure 5 This is an example of a formal photographic image obtained by taking a picture of the side of the knee joint.

[0014] Figure 6 This is an example of a pre-captured image obtained by photographing the side of the knee joint.

[0015] Figure 7 This is a diagram illustrating an example of how the processing unit calculates the offset using the learned model.

[0016] Figure 8 It is a graph of f(x) as a function of the position x of the X-ray tube.

[0017] Figure 9 This is a diagram showing the bones around the knee joint.

[0018] Figure 10 This diagram shows an example of a display performed by the display unit of the operating terminal.

[0019] Figure 11 This is a first diagram illustrating the correction of the imaging position of the X-ray imaging apparatus according to the first embodiment of the present invention.

[0020] Figure 12 This is a second diagram illustrating the correction of the imaging position of the X-ray imaging apparatus according to the first embodiment of the present invention.

[0021] Figure 13 This figure illustrates an example of a method for obtaining positional correction information when photographing the humerus.

[0022] Figure 14 This is a diagram showing X-ray images of the area around the elbow joint before and after position correction.

[0023] Figure 15 This is a diagram illustrating the processing flow of imaging position correction in the automatic correction mode of the X-ray imaging apparatus of the first embodiment.

[0024] Figure 16 This is a diagram illustrating the processing flow of imaging position correction in the manual correction mode of the X-ray imaging apparatus of the first embodiment.

[0025] Figure 17 This is a diagram used to illustrate the photographic orientation of the scapula.

[0026] Figure 18 This is a figure illustrating another example of the X-ray imaging apparatus of the present invention.

[0027] Figure 19 It is shown by Figure 18 The figure shows an example of a display made by the display section of the operating terminal of the X-ray imaging device.

[0028] Figure 20 This is a block diagram showing the structure of the X-ray imaging apparatus according to the second embodiment.

[0029] Figure 21 This is a diagram used to illustrate how parameter information is obtained from pre-captured images.

[0030] Figure 22 This is a diagram illustrating the processing flow of the imaging position correction method of the X-ray imaging apparatus according to the second embodiment.

[0031] Figure 23 This is a block diagram showing the structure of the X-ray imaging apparatus according to the third embodiment.

[0032] Figure 24 It is a diagram used to illustrate how parameter information is obtained from an appearance image.

[0033] Figure 25 This is a block diagram showing the structure of the X-ray imaging apparatus according to the fourth embodiment.

[0034] Figure 26 This is a diagram used to illustrate the acquisition of parameter information from an X-ray image that is different from a pre-taken image. Detailed Implementation

[0035] The embodiments embodied in the present invention will now be described with reference to the accompanying drawings.

[0036] [First Implementation Method]

[0037] Reference Figures 1 to 14 The structure of the X-ray imaging apparatus 100 according to the first embodiment will be described.

[0038] like Figure 1 As shown, the X-ray imaging apparatus 100 includes an X-ray irradiation unit 1 and a detection unit 2. Additionally, the X-ray imaging apparatus 100 includes a top plate 3 for mounting a subject 201, an irradiation unit moving mechanism 4, a top plate moving mechanism 5, a detection unit moving mechanism 6, and an apparatus control unit 7. The X-ray imaging apparatus 100 is configured to perform imaging using X-rays irradiated by the X-ray irradiation unit 1 suspended from the ceiling. Furthermore, the irradiation unit moving mechanism 4 and the top plate moving mechanism 5 are examples of the "moving mechanism" of this disclosure. Additionally, the apparatus control unit 7 is an example of the "movement control unit" of this disclosure.

[0039] X-ray irradiation unit 1 is configured to irradiate the subject 201 with X-rays. Furthermore, X-ray irradiation unit 1 includes an X-ray source (X-ray tube) for irradiating the subject 201 with X-rays and a collimator for adjusting the irradiation range of the X-rays. Additionally, X-ray irradiation unit 1 includes a gripping part 1a, which is provided for the user 202 to hold when manually moving the X-ray irradiation unit 1. Furthermore, X-ray irradiation unit 1 is configured to include a display part 1b, which can display the power assist amount and imaging conditions when the user 202 moves the X-ray irradiation unit 1 while holding the gripping part 1a. Furthermore, display part 1b is also configured to display position correction information, which will be described later. Display part 1b is, for example, a liquid crystal display or an organic EL display.

[0040] The detection unit 2 is configured to detect X-rays that have been irradiated by the X-ray irradiation unit 1 and have passed through the subject 201. For example... Figure 1 As shown, the detection unit 2 includes an X-ray detection unit 21 and an X-ray detection unit 22. The X-ray detection unit 21 is used for imaging with the subject 201 lying on the top plate 3 (recumbent or lateral position), and the X-ray detection unit 22 is used for imaging with the subject 201 standing (standing position). The X-ray detection units 21 and 22 are, for example, FPDs (Flat Panel Detectors) used to detect X-rays that have passed through the subject 201.

[0041] The irradiation unit moving mechanism 4 is configured to change the relative position of the X-ray irradiation unit 1 with respect to the subject 201 by moving the X-ray irradiation unit 1. In the X-ray imaging apparatus 100, the X-ray irradiation unit 1 is supported by the irradiation unit moving mechanism 4 in a manner that allows it to be suspended from the ceiling. Furthermore, the X-ray irradiation unit 1 is supported by the irradiation unit moving mechanism 4 in a manner that allows it to move within the imaging chamber. The irradiation unit moving mechanism 4 is equipped with motors and electromagnetic brakes (not shown) corresponding to the X, Y, and Z directions, respectively. Moreover, the X-ray irradiation unit 1 is configured to be movable along each of the X, Y, and Z directions via the irradiation unit moving mechanism 4. In addition, the irradiation unit moving mechanism 4 is equipped with encoders (not shown) corresponding to the X, Y, and Z directions, respectively, for controlling the movement of the X-ray irradiation unit 1. Furthermore, the irradiation unit moving mechanism 4 is equipped with potentiometers (not shown) corresponding to the X, Y, and Z directions, respectively, and is configured to detect the position of the X-ray irradiation unit 1 in each of the X, Y, and Z directions.

[0042] Furthermore, the X-ray irradiation unit 1 is configured to rotate about the Z-axis. Moreover, the X-ray irradiation unit 1 is configured to rotate about each axis perpendicular to the Z-axis, such as the X-axis and Y-axis. Figure 1In that state, the X-ray irradiation unit 1 can rotate around the Y-axis. The X-ray irradiation unit 1 is configured to change the irradiation direction and angle of the X-rays by rotating around an axis perpendicular to the Z-axis. Furthermore, the irradiation unit moving mechanism 4 is equipped with a motor (not shown) and an electromagnetic brake (not shown) corresponding to the two axes on which the X-ray irradiation unit 1 can rotate. Additionally, the irradiation unit moving mechanism 4 is equipped with an encoder (not shown) and a potentiometer (not shown) corresponding to the two axes on which the X-ray irradiation unit 1 can rotate. Furthermore, the irradiation unit moving mechanism 4 electrically outputs the length of the pulled-out cable by moving the X-ray irradiation unit 1, thereby enabling the detection of the absolute position of the X-ray irradiation unit 1 in the vertical direction (Z-direction).

[0043] The top plate moving mechanism 5 is configured to move the top plate 3 to change the position of the subject 201 relative to the X-ray irradiation unit 1, thereby changing the relative position of the X-ray irradiation unit 1 relative to the subject 201. The top plate moving mechanism 5 is equipped with motors and electromagnetic brakes (not shown) corresponding to the X, Y, and Z directions, respectively. Furthermore, the top plate 3 is configured to be movable along the X, Y, and Z directions via the top plate moving mechanism 5.

[0044] The detection unit moving mechanism 6 includes a supine moving mechanism 61 and an upright moving mechanism 62. X-ray detection units 21 and 22 are held in a manner that allows them to move according to the imaging location of the subject 201 by the supine moving mechanism 61 and the upright moving mechanism 62, respectively. The supine moving mechanism 61 is a mechanism for moving the X-ray detection unit 21, configured to change the position of the X-ray detection unit 21 relative to the subject 201. Similarly, the upright moving mechanism 62 is a mechanism for moving the X-ray detection unit 22, configured to change the position of the X-ray detection unit 22 relative to the subject 201.

[0045] The device control unit 7 is configured to control the entire X-ray imaging device 100. Specifically, the device control unit 7 is configured to perform the following controls: control of X-ray irradiation performed by the X-ray irradiation unit 1, such as the start and stop of X-ray irradiation; control of changes in the X-ray irradiation range of the X-ray irradiation unit 1; control of detection performed by the detection units 2 (X-ray detection units 21 and 22); control of movement of the X-ray irradiation unit 1 via the irradiation unit moving mechanism 4; and control of movement of the top plate 3 via the top plate moving mechanism 5. In addition, the device control unit 7 is configured to control the movement of the X-ray detection unit 21 via the horizontal moving mechanism 61 and the movement of the X-ray detection unit 22 via the vertical moving mechanism 62.

[0046] The device control unit 7 includes a processor such as a CPU (Central Processing Unit) or an FPGA (Field-Programmable Gate Array). Furthermore, the device control unit 7 is configured to receive detection signals from the encoder and potentiometer of the irradiation unit moving mechanism 4. Additionally, the device control unit 7 is configured to control the motor and electromagnetic brake of the irradiation unit moving mechanism 4.

[0047] In addition, such as Figure 2 As shown, the X-ray imaging apparatus 100 includes a processing unit 8, which comprises a processing unit 81 and a storage unit 82. The processing unit 8 is, for example, a PC (Personal Computer) operated by a user 202 such as a radiographer. Furthermore, the processing unit 8 is connected to input devices (not shown) such as a keyboard and mouse, and display devices (not shown) such as a liquid crystal display or an organic EL display. The processing unit 8 is connected to the apparatus control unit 7 in a communicable manner. Alternatively, the processing unit 8 may be integrally formed with the apparatus control unit 7.

[0048] The processing unit 81 is configured to: determine the outer edges of multiple predetermined portions of a bone of the subject 201 in an X-ray image captured based on the detection signals of the detection units 2 (X-ray detection units 21 and 22), and acquire positional correction information for correcting the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 based on the determined positional relationship between the outer edges of the multiple predetermined portions. The processing unit 81 includes a CPU, a GPU (Graphics Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), etc. Furthermore, the processing unit 81 is an example of the "correction information acquisition unit" of this disclosure. Additionally, the bone is an example of the "photographic object" of this disclosure.

[0049] Furthermore, the position correction information includes the relative direction and amount of movement for correcting the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 so that an X-ray image can be captured showing the positional relationship between the outer edges of multiple specified parts in a specified positional relationship.

[0050] Storage unit 82 includes non-volatile storage media such as HDD (Hard Disk Drive) or SSD (Solid State Drive). Storage unit 82 stores learned models (learned models 82a, 82b, 82c, 82d, and 82e) obtained by machine learning using X-ray images of the bone as input data. Learned models 82a, 82b, 82c, 82d, and 82e are, for example, models using U-Net. Furthermore, machine learning using X-ray images as input data can be any of supervised learning, unsupervised learning, or reinforcement learning. In the first embodiment, the learned models stored in storage unit 82 exist for each of a plurality of defined portions of the radiographed area. The learned models stored in storage unit 82 learn feature points of each portion of the plurality of defined portions of the radiographed area. Learned models 82a and 82b are learned models used when photographing the knee joint of the subject 201. Furthermore, the learned models 82c, 82d, and 82e are the learned models used when photographing the elbow joint of the subject 201. In addition, the learned models (learned models 82a, 82b, 82c, 82d, and 82e) can also be stored (saved) in a server connected to the X-ray imaging device 100 via a network. Furthermore, the storage unit 82 can also store learned models created for each imaging site.

[0051] Furthermore, in the first embodiment, when photographing the knee joint of the subject 201, the processing unit 81 is configured to: input X-ray images of the learned models 82a and 82b, thereby acquiring the outer edges of multiple predetermined parts based on the input X-ray images, and calculating position correction information based on the acquired outer edges of the multiple predetermined parts. Additionally, in the first embodiment, when photographing the elbow joint of the subject 201, the processing unit 81 is configured to: input X-ray images of the learned models 82c, 82d, and 82e, thereby acquiring the outer edges of multiple predetermined parts based on the input X-ray images, and calculating position correction information based on the acquired outer edges of the multiple predetermined parts.

[0052] Additionally, the X-ray imaging apparatus 100 includes an operation terminal 9. The operation terminal 9 is a terminal for the user 202 to operate the X-ray imaging apparatus 100. The operation terminal 9 is communicatively connected to the apparatus control unit 7 and the processing unit 8. The user 202 can use the operation terminal 9 to perform operations such as changing the position of the X-ray irradiation unit 1 and capturing X-ray images. The operation terminal 9 includes a display unit 91 and an operation unit 92. The display unit 91 is, for example, a liquid crystal display or an organic EL display. The operation unit 92 is a user interface for operating the X-ray imaging apparatus 100. The operation unit 92 includes, for example, a power switch or a remote control. Alternatively, the operation unit 92 may include a touch panel provided on the display unit 91.

[0053] The X-ray imaging apparatus 100 is configured to notify the user of position correction information acquired by the processing unit 81. In the first embodiment, the X-ray imaging apparatus 100 is configured to notify the user of position correction information via a display unit 91 on the operation terminal 9. Alternatively, in the first embodiment, the X-ray imaging apparatus 100 can also notify the user of position correction information via a display unit 1b on the X-ray irradiation unit 1. Details of the display performed by the display unit 91 will be described later.

[0054] (Correction during knee joint photography)

[0055] like Figure 3 As shown, during knee radiography, with the subject 201 placed above the top plate 3, the lying position of the subject 201 is adjusted using cushioning pads 203 and 204 to ensure appropriate knee position, thigh and lower leg rotation, and lower leg elevation (knee flexion angle). Then, X-ray images of the subject 201 are taken in the adjusted lying position.

[0056] Furthermore, the X-ray imaging device 100 is configured to determine (estimate) such as based on X-ray images. Figure 4 The femur 31 is shown in multiple designated portions, and position correction information is obtained for correcting the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201.

[0057] In addition, the X-ray imaging device 100 is configured to capture pre-captured images 24 (see reference). Figure 6 The pre-captured image 24 is based on the radiation dose ratio for capturing the final image 23 (see reference). Figure 5The X-ray image 23 is generated by irradiation with a low dose of X-rays during the initial imaging phase (X-ray irradiation unit 1) relative to the bones of the subject 201. For example, the radiation dose when taking the preliminary image 24 is approximately 1 / 50 to 1 / 100 of the radiation dose when taking the final image 23. In the first embodiment, the final image 23 is an image used for diagnosing diseases. Furthermore, the final image 23 is an example of the "image after position correction" of this disclosure, and the preliminary image 24 is an example of the "image before position correction" of this disclosure.

[0058] In addition, in the first embodiment, the processing unit 81 of the X-ray imaging apparatus 100 is configured to acquire position correction information based on the positional relationship between the outer edges of multiple predetermined portions of the bone of the subject 201 in the pre-captured image 24.

[0059] In the first embodiment, the X-ray imaging apparatus 100 is configured to: capture images such as Figure 5 The medial condyle 31a of the femur 31 as shown (see reference) Figure 6 ) outer edge and lateral condyle 31b (refer to Figure 6 The X-ray images of overlapping outer edges of the X-ray irradiation unit 1 are processed by the processing unit 81 to obtain position correction information and correct the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201. Furthermore, the medial condyle 31a and the lateral condyle 31b are examples of the "multiple specified parts" of this disclosure.

[0060] The processing unit 81 acquires the relative positional offset between the outer edges of multiple predetermined portions of a bone in the X-ray image based on the positional relationship between them. Furthermore, the processing unit 81 is configured to acquire position correction information based on the acquired relative positional offset between the outer edges of the multiple predetermined portions. In the first embodiment, when imaging the side of the knee joint, the processing unit 81 of the X-ray imaging apparatus 100 is configured to acquire position correction information based on the positional offset between the outer edge of the medial condyle 31a (the portion of the femur 31 on the knee side opposite to the midline side) and the outer edge of the lateral condyle 31b (the portion of the femur 31 on the knee side opposite to the midline side).

[0061] Furthermore, the processing unit 81 is configured to obtain the relative positional offset between the outer edges of multiple predetermined portions of the bone of the subject 201 in the X-ray image based on the overlap between the outer edges of these portions. In the first embodiment, the processing unit 81 is as follows: Figure 7As shown, the relative positional offsets between the outer edges of multiple defined portions of the femur 31 on the knee side of the subject 201 were obtained using the learned models 82a and 82b. Specifically, the processing unit 81 determines (estimates) the outer edge of the medial condyle 31a based on the pre-captured image 24 through segmentation processing based on the learned model 82a. Furthermore, the processing unit 81 determines (estimates) the outer edge of the lateral condyle 31b based on the pre-captured image 24 through segmentation processing based on the learned model 82b. Moreover, the processing unit 81 is configured to calculate the offset (offset amount and offset direction) between the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31 based on the outer edges of the medial condyle 31a and the lateral condyle 31b determined (estimated) based on the pre-captured image 24. In the analysis of offset amount and offset direction performed by the processing unit 81, assuming that one of the medial condyle 31a and the lateral condyle 31b is moved, the position that minimizes the area caused by the offset between the moved medial condyle 31a and the lateral condyle 31b is searched in such a way that the trailing edges of the outer edges of the medial condyle 31a and the lateral condyle 31b are aligned. The offset amount and offset direction are thus determined. Furthermore, in the analysis of offset amount and offset direction performed by the processing unit 81, the portion containing the maximum offset amplitude can also be determined from the image in which the outer edges of the medial condyle 31a and the lateral condyle 31b are extracted.

[0062] Furthermore, the processing unit 81 is configured such that, when imaging the knee side of the femur 31 of the subject 201, it calculates position correction information based on the calculated offset between the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31. This information is used to correct the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 so that an X-ray image can be captured showing the overlapping outer edges of multiple predetermined portions. Specifically, the processing unit 81 calculates the movement direction and amount of movement (movement distance) of the X-ray irradiation unit 1 based on the calculated offset (movement vector) between the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31 as position correction information. The position correction information is obtained by using, for example... Figure 8As shown, the offset f between the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31 varies linearly with respect to the X-ray tube position x (X-ray irradiation point). In the first embodiment, based on the offset f1 between the outer edges of the medial condyle 31a and the lateral condyle 31b calculated from the pre-captured image 24 taken at the X-ray tube position x1 and the tilt α of the X-ray tube position x as a function of x, an estimated position x' is calculated (the position where the offset f is 0) where an X-ray image of multiple specified portions (medial condyle 31a and lateral condyle 31b) can be captured with their outer edges overlapping each other. The tilt α varies depending on various parameters, including device parameters such as SID (Source to image receptor distance) and parameters set corresponding to the subject 201 (patient) during imaging.

[0063] Alternatively, the pre-captured image 24 can be preprocessed before determining the outer edges of the medial condyle 31a and the lateral condyle 31b. For example, preprocessing can be performed to remove unwanted signals such as noise using a high-pass filter. Alternatively, as preprocessing, the captured X-ray image of the knee can be reversed left to right (turning the left knee into the right knee or the right knee into the left knee). In this case, even if the storage unit 82 only stores the learned model corresponding to one of the right or left knees, the processing unit 81 can calculate the offset between the outer edges of the medial condyle 31a and the lateral condyle 31b of both the right and left knees and obtain position correction information.

[0064] Alternatively, the processing unit 81 may, in addition to basing its analysis on the characteristics of the medial condyle 31a and the lateral condyle 31b, also base its analysis on the characteristics of the subject 201. Figure 9 The bones shown, excluding the femur 31, such as the tibia 32, fibula 33, patella 34, and sesamoid bone 35, are used to determine the outer edges of the medial condyle 31a and the lateral condyle 31b, and to calculate the degree of overlap (positional relationship) between the medial condyle 31a and the lateral condyle 31b.

[0065] For example, when there is a feeling of external rotation (outward toeing) in the knee, the fibula 33 moves further posteriorly (in the direction of separation from the patella 34), thus making the proximal tibiofibular joint more prominent. Furthermore, the sesamoid bone 35 separates from the condyles of the femur 31 (medial condyle 31a and lateral condyle 31b). Conversely, when there is a feeling of internal rotation (inward toeing) in the knee, the fibula 33 moves further anteriorly (closer to the patella 34), thus increasing its overlap with the tibia 32. Moreover, the sesamoid bone 35 is closer to the condyles of the femur 31 (medial condyle 31a and lateral condyle 31b). Therefore, it is possible to determine whether the knee feels externally rotated (outward toeing) or internally rotated (inward toeing) based on the position of the fibula 33 or the sesamoid bone 35.

[0066] Furthermore, if a positional shift occurs between the medial condyle 31a and the lateral condyle 31b of the femur 31 in the vertical direction extending from the femur 31, a positional shift also occurs between the medial plateau 32a and the lateral plateau 32b of the tibia 32. Therefore, it is possible to determine whether a vertical positional shift exists between the medial condyle 31a and the lateral condyle 31b of the femur 31 based on the positional relationship between the medial plateau 32a and the lateral plateau 32b of the tibia 32.

[0067] Additionally, the display unit 91 of the operating terminal 9 displays the relative movement direction and relative movement amount of the X-ray irradiation unit 1 relative to the bone of the subject 201, used to correct the position of the X-ray image so that the positional relationship between the outer edges of multiple specified parts can be captured in a specified positional relationship, as a notification of position correction information. For example, as Figure 10 As shown, the display unit 91 of the operating terminal 9 displays a graph showing the relative movement amount and direction of the X-ray irradiation unit 1 relative to the bone of the subject 201. Thus, the user 202 can determine the direction and degree of correction of the position of the X-ray irradiation unit 1 relative to the bone of the subject 201 based on the display on the display unit 91. Furthermore, the display provided by the display unit 91 can be either a simple text display such as "Movement direction: 10 o'clock, Movement amount: 3cm," or a display combining images, diagrams, and text.

[0068] Additionally, the display unit 1b of the X-ray irradiation unit 1 (see reference) Figure 1 The X-ray irradiation unit 1 is configured to display in conjunction with the display unit 91. Thus, the user 202 can hold the X-ray irradiation unit 1 in the holding unit 1a (see reference 1). Figure 1 In the state of the X-ray irradiation unit 1, the relative movement direction and relative movement amount of the X-ray irradiation unit 1 relative to the bone of the subject 201 required for correcting the imaging position are confirmed by the display unit 1b.

[0069] (Control of the movement of the X-ray irradiation unit)

[0070] The X-ray imaging apparatus 100 is configured to control the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 based on position correction information. Furthermore, in the first embodiment, the X-ray imaging apparatus 100 includes an automatic correction mode and a manual correction mode for correcting the imaging position. In the automatic correction mode, the imaging position is automatically corrected under the control of the device control unit 7, while in the manual correction mode, the imaging position is corrected manually by the user 202. Moreover, the X-ray imaging apparatus 100 is configured to switch between the automatic and manual correction modes based on a switching operation performed by the user 202.

[0071] In the first embodiment, in the automatic calibration mode of the X-ray imaging apparatus 100, the apparatus control unit 7 is configured to perform automatic calibration based on position calibration information. This automatic calibration involves moving the position of the X-ray irradiation unit 1 to automatically change the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201. Furthermore, the X-ray imaging apparatus 100 is configured to restrict the movement of the X-ray irradiation unit 1 during manual calibration (manual calibration mode). This manual calibration is performed by moving the X-ray irradiation unit 1 based on the operation of the user 202.

[0072] Specifically, in automatic correction mode, the device control unit 7 performs the following control based on the position correction information obtained by the processing unit 81: It automatically moves the X-ray irradiation unit 1 so that the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 is such that an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship. That is, through the control of the device control unit 7 based on the position correction information, the irradiation unit moving mechanism 4 moves the X-ray irradiation unit 1 to a position where an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship.

[0073] Additionally, in the X-ray imaging apparatus 100, such as Figure 11 and Figure 12 As shown, by changing the position in the horizontal direction (XY direction) based on the fan-shaped beam characteristics of the X-rays irradiated from the X-ray irradiation unit 1, correction can be performed without changing the X-ray irradiation angle of the X-ray irradiation unit 1. For example, by changing the position of the X-ray irradiation point (X-ray irradiation unit 1) from... Figure 11 The position of the left image is moved to Figure 12The position shown in the left image allows X-rays to pass through the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31. Therefore, even without changing the X-ray irradiation angle of the X-ray irradiation unit 1, it is possible to capture an image showing the overlapping outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31 (see reference). Figure 12 The X-ray image is shown in the right figure. Furthermore, when correcting the imaging position, in addition to changing the position in the horizontal direction (XY direction), the X-ray irradiation angle of the X-ray irradiation unit 1 and the position of the X-ray irradiation unit 1 in the vertical direction (Z direction) can also be changed. Additionally, when correcting the imaging position, in addition to moving the X-ray irradiation unit 1 via the irradiation unit moving mechanism 4, the top plate 3 on which the subject 201 is placed can also be moved via the top plate moving mechanism 5.

[0074] Furthermore, when the X-ray irradiation unit 1 is moved based on the operation of user 202, the device control unit 7 performs control to limit the movement of the X-ray irradiation unit 1 based on the position correction information obtained by the processing unit 81. Specifically, the device control unit 7 is configured to control the locking of the electromagnetic brake of the irradiation unit moving mechanism 4 based on the position correction information in manual correction mode, thereby limiting the movement of the X-ray irradiation unit 1.

[0075] Thus, in the first embodiment, the device control unit 7 is configured to control the relative position of the X-ray irradiation unit 1 with respect to the bones of the subject 201 based on the position correction information obtained by the processing unit 81.

[0076] (Correction when photographing the elbow joint)

[0077] Furthermore, in the first embodiment, the processing unit 81 is configured to, when imaging the elbow side (elbow joint) of the humerus 36 of the subject 201, also acquire the relative positional offset between the outer edges of multiple predetermined portions of the bone of the subject 201 based on the positional relationship between the outer edges of multiple predetermined portions in the X-ray image. In the first embodiment, the processing unit 81 uses learned models 82c, 82d, and 82e to acquire the relative positional offset between the outer edges of multiple predetermined portions of the elbow side of the humerus 36 of the subject 201. Additionally, when imaging the elbow joint (elbow side of the humerus 36) of the subject 201, X-ray detection units 21 and 22 (see reference 22) can also be used. Figure 1 Any one of them.

[0078] In the first embodiment, the processing unit 81 is configured to calculate position correction information for correcting the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 to a position capable of capturing X-ray images of multiple predetermined portions concentrically. Specifically, the processing unit 81 uses learned models 82c, 82d, and 82e to determine (estimate) portions A, B, and C of the humerus 36, respectively. Then, the processing unit 81 acquires the relative position offsets between the determined portions A, B, and C of the humerus 36. Furthermore, based on the obtained relative position offsets between portions A, B, and C of the humerus 36, the processing unit 81 calculates position correction information for correcting the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 to a position capable of capturing X-ray images of multiple predetermined portions (parts A, B, and C) concentrically. In the first embodiment, when imaging the elbow joint, the processing unit 81 calculates the movement direction and movement amount (movement distance) of the X-ray irradiation unit 1 to correct the position x of the X-ray tube bulb (X-ray irradiation point) so that an X-ray image can be captured in which the outer edges of portions A and C overlap and the outer edges of multiple predetermined portions (parts A, B, and C) are concentrically projected, and uses this as position correction information. Furthermore, the method for calculating the position correction information is the same as the method described above for imaging the knee joint.

[0079] Specifically, in such Figure 13 In the case of X-ray imaging as shown in the figure above, where X-rays are irradiated from the lateral side of the humerus 36 toward the head 36a of the humerus, the outer edges of portions A and C on the cubital side of the humerus 36 overlap, and the outer edges of multiple designated portions (parts A, B, and C) on the cubital side of the humerus 36 are shown in concentric circles (see reference). Figure 13 The positional correction information for correcting the relative position of the X-ray irradiation section 1 with respect to the bones of the subject 201 is calculated in the manner shown in the figure below. Part A is the convex portion of the head of the humerus 36a. Part B is the concave portion of the trochlea 36b of the humerus 36, and part C is the convex portion of the trochlea 36b of the humerus 36. Furthermore, parts A, B, and C are examples of the "multiple specified parts" of this disclosure. In addition, the positional correction information for taking pictures of the elbow joint can also be calculated based on the positional relationship of at least one of the outer edges of the radius 37 and the ulna 38 and the positional relationship of the multiple specified parts (parts A, B, and C) on the cubital side of the humerus 36. Figure 13 The following example is shown: the position reflected upwards from part C of the humerus 36 (the convex part of the trochlea 36b) (see reference). Figure 13In the central diagram, the outer edges of parts A (the convex portion of the humeral head 36a) and C (the convex portion of the trochlea 36b) overlap concentrically, and the position of the outer edge of part B (the concave portion of the trochlea 36b) is concentrically reflected on the inner side of the outer edges of parts A and C (see reference). Figure 13 (See the image below) Correction is performed. Based on the position correction information, the upper arm is raised, the worktable (not shown) on which the upper arm is mounted is raised, or the position of the X-ray irradiation unit 1 is changed, thereby adjusting the position reflected by the upward offset from the portion C (trochlea 36b) of the humerus 36 (see the image below). Figure 13 The central image is used to correct the relative position of the X-ray irradiation unit 1 with respect to the bones of the subject 201.

[0080] Furthermore, the pre-captured image 24 and the correction of the shooting position can be performed multiple times. For example, it can also be done as follows: Figure 14 As shown, after correcting the imaging position based on the pre-captured image 24a of the elbow joint of the subject 201, the pre-captured image 24b is captured again. Furthermore, the imaging position can be corrected again based on the second pre-captured image 24 (pre-captured image 24b), and the final image 23 can then be captured. Figure 14 In the example shown, by taking two pre-shot images 24 and performing two position corrections, an X-ray image (formal image 23) was obtained in which the joint space could be observed between the humerus 36 and the ulna 38.

[0081] (Position correction processing)

[0082] Next, refer to Figure 15 The process flow for position correction using the automatic correction mode of the X-ray imaging apparatus 100 of the first embodiment will be described.

[0083] First, in step 301, the subject 201 is irradiated with X-rays from the X-ray irradiation unit 1. In step 301, the radiation dose is less than that used when taking the formal image 23, as described above. Furthermore, step 301 is an example of the "irradiation step" of this disclosure. Then, after step 301 is completed, the processing steps proceed to step 302.

[0084] In step 302, X-rays that have passed through the subject 201 are detected. In step 302, as described above, the detection unit 2 (X-ray detection unit 21 or 22) detects the X-rays that have passed through the subject 201. Therefore, a pre-image 24 is captured in step 302. Furthermore, step 302 is an example of the "detection step" of this disclosure. Then, after step 302 is completed, the processing steps proceed to step 303.

[0085] In step 303, position correction information is acquired. In step 303, as described above, the outer edges of each of several predetermined portions of the bone of the subject 201 in the X-ray image (pre-image 24) captured based on X-ray detection are determined, and position correction information for correcting the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 is acquired based on the positional relationship between the determined outer edges of the several predetermined portions. Step 303 is an example of the "correction information acquisition step" of this disclosure. After step 303 is completed, the processing steps proceed to step 304. The transfer to step 304 can be automatic or based on operations performed by the user 202, such as operations performed on the operation unit 92 of the operation terminal 9. Furthermore, after step 303 is completed, the position correction information can be displayed on the display unit 91 or the display unit 1b.

[0086] Then, in step 304, automatic position correction is performed. In step 304, control is performed to change the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 based on the position correction information. Specifically, the device control unit 7 controls the irradiation unit movement mechanism 4 based on the position correction information as described above, thereby moving the X-ray irradiation unit 1. As a result, the relative position of the X-ray irradiation unit 1 with respect to the subject 201 (the bone of the subject 201) is corrected. Then, the position correction process using the X-ray imaging device 100 is completed. Furthermore, step 304 is an example of the "position correction step" of this disclosure.

[0087] Then, after step 304 is completed, user 202 performs an operation to capture an X-ray image in a state where the imaging position has been corrected. Alternatively, the X-ray image can be captured automatically after step 304 is completed.

[0088] Next, refer to Figure 16 The process of position correction using the manual correction mode of the X-ray imaging apparatus 100 of the first embodiment will be described.

[0089] First, steps 401, 402, and 403 are performed in the same manner as steps 301, 302, and 303 in the automatic calibration mode. Then, after step 403 is completed, the processing proceeds to step 404. Furthermore, step 401 is an example of the "irradiation step" of this disclosure, and step 402 is an example of the "detection step" of this disclosure. Additionally, step 403 is an example of the "calibration information acquisition step" of this disclosure.

[0090] In step 404, position correction information is displayed. In step 404, the position correction information obtained in step 403 is displayed by display unit 91 and display unit 1b as described above. Then, after the position correction information is displayed by display unit 91 and display unit 1b (after step 404 is completed), the processing steps proceed to step 405. Furthermore, step 404 is an example of the "position correction step" of this disclosure.

[0091] In step 405, manual position correction is performed. In step 405, the user 202 moves the X-ray irradiation unit 1 while checking the display on the display unit 91 or the display unit 1b, thereby correcting the imaging position. In the imaging position correction in step 405, the X-ray irradiation unit 1 can be moved either by the user 202 holding the handle 1a of the X-ray irradiation unit 1, or by the irradiation unit moving mechanism 4 based on the operation of the operation unit 92 of the operation terminal 9 by the user 202.

[0092] Then, after step 405 is completed, user 202 performs an operation to capture an X-ray image, thereby capturing an X-ray image in a state where the imaging position has been corrected.

[0093] (Effects of the first implementation method)

[0094] In the first embodiment, the following effects can be obtained.

[0095] In the first embodiment, positional correction information for correcting the relative position of the X-ray irradiation unit 1 relative to the bone (the object of imaging) of the subject 201 is obtained based on the positional relationship between the outer edges of multiple predetermined portions of the bone in the X-ray image. Furthermore, the positional correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 so that an X-ray image can be captured showing the positional relationship between the outer edges of the multiple predetermined portions in a predetermined positional relationship. Thus, by obtaining positional correction information containing the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 so that an X-ray image can be captured showing the positional relationship between the outer edges of the multiple predetermined portions in a predetermined positional relationship, the user 202, such as a radiologist, can perform high-precision correction of the imaging position based on the displayed (notified) results by displaying (notifying) the required relative movement direction and relative movement amount of the obtained positional correction information. As a result, the number of times X-ray image imaging and imaging position correction are repeatedly performed can be reduced. Therefore, an X-ray imaging apparatus 100 and an imaging position correction method can be provided that can acquire accurate diagnostic X-ray images while suppressing increases in radiation dose and imaging time. Furthermore, by using the acquired position correction information to control the relative position of the X-ray irradiation unit 1, the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 can be precisely corrected to a position that allows for the capture of X-ray images showing the positional relationship between the outer edges of multiple predetermined portions in a position suitable for diagnosis. As a result, the number of times X-ray image capture and imaging position correction are repeatedly performed can be reduced. Therefore, an X-ray imaging apparatus 100 and an imaging position correction method can be provided that can acquire accurate diagnostic X-ray images while suppressing increases in radiation dose and imaging time.

[0096] Furthermore, the X-ray imaging apparatus 100 of the first embodiment described above can achieve the following further effects by being configured as follows.

[0097] In the first embodiment, the X-ray imaging apparatus 100 is configured to display (notify) position correction information acquired by the processing unit 81 (correction information acquisition unit). Therefore, by displaying (notifying) the position correction information acquired by the processing unit 81, the user 202 can grasp the relative movement direction and amount of the position used to correct the relative position of the X-ray irradiation unit 1 relative to the bone (the object of imaging) of the subject 201 so that an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship. As a result, the user 202 can easily correct the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 so that an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship. Furthermore, the X-ray imaging apparatus 100 is configured to control the change of the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 based on the position correction information. Therefore, the X-ray imaging device 100 controls the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 based on the position correction information. Thus, the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 can be easily corrected to a position that allows the X-ray image to be captured showing the positional relationship between the outer edges of multiple specified parts in a specified positional relationship.

[0098] Furthermore, in the first embodiment, the device control unit 7 (movement control unit) is configured to control the relative position of the X-ray irradiation unit 1 relative to the bone (the object of imaging) of the subject 201 using the irradiation unit moving mechanism 4 (movement mechanism) based on the position correction information acquired by the processing unit 81 (correction information acquisition unit). Therefore, since the device control unit 7 controls the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 using the irradiation unit moving mechanism 4 based on the position correction information, the imaging position can be corrected more easily compared to the case where the user 202 performs correction manually based on the position correction information.

[0099] Furthermore, in the first embodiment, the device control unit 7 (movement control unit) performs the following control based on the position correction information acquired by the processing unit 81 (correction information acquisition unit): it automatically moves the position of the X-ray irradiation unit 1 so that the relative position of the X-ray irradiation unit 1 with respect to the bone (the object of imaging) of the subject 201 is such that an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship. Therefore, since the position correction of the X-ray irradiation unit 1 is performed automatically by the device control unit 7, it is easier to correct the position of the X-ray irradiation unit 1 compared to the case where the position correction is performed manually by the user 202.

[0100] Furthermore, in the first embodiment, when the X-ray irradiation unit 1 is moved based on the operation of user 202, the device control unit 7 (movement control unit) performs control to limit the movement of the X-ray irradiation unit 1 based on the position correction information acquired by the processing unit 81 (correction information acquisition unit). Therefore, even when the X-ray irradiation unit 1 is moved manually by user 202 to correct the imaging position, the device control unit 7 can limit the movement of the X-ray irradiation unit 1 based on the position correction information. As a result, when the X-ray irradiation unit 1 is moved manually by user 202 to correct the imaging position, it is possible to prevent the X-ray irradiation unit 1 from moving by an amount exceeding the required correction amount or from moving in a direction other than the required correction direction due to the user 202's manual operation.

[0101] Furthermore, in the first embodiment, the display unit 91 displays the relative movement direction and amount of the X-ray irradiation unit 1 relative to the bone (the object of imaging) of the subject 201, which is used to correct the position of the X-ray image so that the positional relationship between the outer edges of the multiple predetermined parts can be captured in a predetermined positional relationship. This serves as a notification of the position correction information acquired by the processing unit 81 (correction information acquisition unit). Thus, by visually recognizing the relative movement direction and amount of the X-ray irradiation unit 1 relative to the bone of the subject 201 displayed on the display unit 91, the user 202 can easily determine in which direction and to what extent the imaging position needs to be corrected, and thus manually perform the imaging position correction.

[0102] Furthermore, in the first embodiment, the processing unit 81 (correction information acquisition unit) is configured to acquire relative positional offsets between the outer edges of multiple predetermined portions of a bone (the object being photographed) in an X-ray image based on the positional relationship between the outer edges of these predetermined portions, and to acquire position correction information based on these acquired relative positional offsets. Therefore, since the relative positional offsets between the outer edges of the multiple predetermined portions are acquired from the X-ray image, position correction information can be acquired by comparing the relative positional offsets between the outer edges of the multiple predetermined portions in the X-ray image with the relative positional offsets between the outer edges of the multiple predetermined portions in a state that makes the positional relationship between the outer edges of the multiple predetermined portions a predetermined positional relationship.

[0103] Furthermore, in the first embodiment, the processing unit 81 (correction information acquisition unit) acquires the relative positional offset between the outer edges of multiple predetermined portions of the bone of the subject 201 based on the overlap between the outer edges of these portions in the X-ray image. Then, when imaging the knee side of the femur 31 of the subject 201, the processing unit 81 calculates positional correction information to correct the relative position of the X-ray irradiation unit 1 relative to the subject 201 so that an X-ray image can be captured where the outer edges of the medial condyle 31a and the lateral condyle 31b (the outer edges of the multiple predetermined portions) overlap. Thus, when imaging the knee side (around the knee joint) of the femur 31 of the subject 201, the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 is corrected according to the positional correction information to a position where an X-ray image can be captured where the outer edges of the medial condyle 31a and the lateral condyle 31b (the outer edges of the multiple predetermined portions) overlap. As a result, X-ray images can be taken that can be used to accurately identify diseases that occur around the knee joint, such as osteochondritis dissecans and osteoarthritis of the knee.

[0104] Furthermore, in the first embodiment, the processing unit 81 (correction information acquisition unit) acquires the relative positional offset between the outer edges of multiple predetermined portions of the bone of the subject 201 based on the positional relationship between the outer edges of these portions in the X-ray image. Then, when imaging the elbow side of the humerus 36 of the subject 201, the processing unit 81 calculates positional correction information to correct the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 so that an X-ray image can be captured showing the concentric circles of the outer edges of the multiple predetermined portions (parts A, B, and C) of the humerus 36. Thus, when imaging the elbow side (around the elbow joint) of the humerus 36 of the subject 201, the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 is corrected according to the positional correction information to a position where an X-ray image can be captured showing the concentric circles of the multiple predetermined portions (parts A, B, and C) of the humerus 36. As a result, X-ray images can be taken that can be used to accurately identify diseases that occur around the elbow joint, such as osteochondritis dissociatus and osteoarthritis of the elbow.

[0105] Furthermore, in the first embodiment, the processing unit 81 (correction information acquisition unit) is configured to acquire position correction information based on the positional relationship between the outer edges of multiple predetermined portions of the bone of the subject 201 in the pre-image 24 (image before position correction). The pre-image 24 is an X-ray image generated based on X-ray irradiation with a lower radiation dose than when the formal image 23 (image after position correction) is taken. The formal image 23 is an X-ray image taken after the relative position of the X-ray irradiation unit 1 relative to the bone (object of imaging) of the subject 201 has been corrected. As a result, the radiation dose to the subject 201 during imaging before position correction can be reduced, and thus the increase in the radiation dose to the subject 201 until an X-ray image that can be accurately diagnosed can be obtained can be further suppressed.

[0106] Furthermore, in the first embodiment, the processing unit 81 (correction information acquisition unit) is configured to input an X-ray image into the learned models 82a and 82b (learned models 82c, 82d, and 82e), thereby acquiring the outer edges of multiple predetermined parts based on the input X-ray image, and calculating position correction information based on the acquired outer edges of the multiple predetermined parts. Thus, by acquiring the outer edges of multiple predetermined parts using the learned models 82a and 82b (learned models 82c, 82d, and 82e), and calculating position correction information based on the acquired outer edges of the multiple predetermined parts, the learned models obtained by learning the feature points of the observed object's parts can acquire the outer edges of multiple predetermined parts with high precision. As a result, position correction information can be calculated with high precision.

[0107] [Second Implementation]

[0108] Reference Figure 20 and Figure 21 The second embodiment will be described. In this second embodiment, the processing unit 681 sets the tilt angle α of the X-ray tube bulb position x as a function f(x) based on the parameter information obtained from the pre-captured image 24, and calculates position correction information. Furthermore, in the figures, parts with the same structure as in the first embodiment are labeled with the same reference numerals.

[0109] (Structure of the X-ray imaging apparatus according to the second embodiment)

[0110] like Figure 20As shown, the X-ray imaging apparatus 600 includes a processing unit 608. The processing unit 608 includes a processing section 681. Similar to the processing unit 8 of the first embodiment, the processing unit 608 is, for example, a PC operated by a user 202 such as a radiographer. Similar to the processing section 81 of the first embodiment, the processing section 681 includes a CPU, a GPU, and RAM. The processing section 681 is an example of the "correction information acquisition section" of this disclosure. In the second embodiment, for example, X-ray imaging of the knee of the subject 201 is performed by the X-ray imaging apparatus 600.

[0111] Similar to the processing unit 81 in the first embodiment, when photographing the knee side of the femur 31 of the subject 201, the processing unit 681 calculates the offset (offset amount and offset direction) between the outer edge of the medial condyle 31a and the outer edge of the lateral condyle 31b of the femur 31 based on the pre-photographed image 24. Then, based on the calculated offset between the outer edges of the medial condyle 31a and the lateral condyle 31b of the femur 31, the processing unit 681 calculates the movement direction and movement amount (movement distance) of the X-ray irradiation unit 1 at the photographic position where the outer edges of the medial condyle 31a and the lateral condyle 31b overlap, as position correction information. At this time, similar to the first embodiment, the processing unit 681 calculates the offset f1 between the outer edges of the medial condyle 31a and the lateral condyle 31b calculated based on the pre-photographed image 24 and the tilt α of the X-ray tube position x as a function f(x), using the following formula (1) (refer to...). Figure 8 ), to calculate the estimated position x' of the position where the outer edges of the inner condyle 31a and the outer condyle 31b are estimated to be able to capture an X-ray image (the position where the offset f is 0) that overlaps with each other.

[0112] [Number 1]

[0113]

[0114] Here, the tilt angle α varies depending on various parameters, including device parameters such as SID (Source to image receptor distance) and subject-specific parameters set during imaging corresponding to the subject 201 (patient). Specifically, the tilt angle α is calculated using the following formula (2).

[0115] [Number 2]

[0116]

[0117] Here, SID is the longitudinal position of the X-ray tube bulb, which is a device parameter, and is the distance from the detection surface of the detection unit 2 (X-ray detection unit 21 and X-ray detection unit 22) to the X-ray irradiation unit 1. Regarding SID, a recommended value can be automatically set based on the body part being imaged, or an actual value can be obtained from the device control unit 7. Additionally, b represents the height from the detection surface to the lateral condyle 31b. D represents the actual distance between the medial condyle 31a and the lateral condyle 31b of the subject 201. θ represents the inclination of the straight line connecting the medial condyle 31a and the lateral condyle 31b relative to the perpendicular line drawn from the detection surface. Height b, distance D, and angle θ are inherent parameters of the subject. Height b and distance D are body-derived parameters that vary depending on the size of the subject 201 (bone size). Angle θ is a posture-derived parameter that varies depending on the posture of the subject 201. In the second embodiment, the processing unit 681 automatically calculates parameters derived from the body shape based on the pre-captured image 24. That is, it automatically calculates the value of the tilt angle α based on the pre-captured image 24.

[0118] In the second embodiment, the processing unit 681 calculates position correction information based on parameter information corresponding to the actual distance between the medial condyle 31a and lateral condyle 31b (a plurality of predetermined portions) of the bone (the object of radiography) of the subject 201, thereby calculating the tilt angle α. The processing unit 681 detects the size of the target portion of the subject 201 in the X-ray image of the subject 201 as parameter information. Specifically, the processing unit 681 detects the size of the target portion of the subject 201 from the X-ray image taken for obtaining position correction information, i.e., the pre-image 24, as parameter information. Then, the processing unit 681 calculates the height b and distance D based on the detected parameter information, thereby calculating the position correction information.

[0119] like Figure 21 As shown, the detection target portion of the subject 201 is, for example, portion 31c and portion 31d of the femur 31 and portion 32c of the tibia 32 of the subject 201. In the second embodiment, the detection target portions (parts 31c, 31d, and 32c) of the subject 201 whose size is detected as parameter information are portions different from multiple predetermined portions (medial condyle 31a and lateral condyle 31b) of the photographic object of the subject 201, which are photographed in a predetermined positional relationship. The detection target portion is a portion that is correlated with the predetermined portions in size or shape.

[0120] The processing unit 681 performs segmentation processing, for example, using a pre-stored learned model or similar algorithm. This allows it to detect the size (width) of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32 of the subject 201 from the pre-captured image 24, using this as parameter information. For instance, the processing unit 681 uses the learned model to detect the contour lines of the femur 31 and tibia 32 in the pre-captured image 24. Then, the processing unit 681 detects the size of the target portion of the subject 201 by detecting the width (number of pixels) of portions 31c, 31d, and 32c based on the detected contour lines. The positions of portions 31c, 31d, and 32c in the pre-captured image 24 can be extracted from the shape or position coordinates of the contours, or obtained based on input operations performed by the user 202.

[0121] Then, the processing unit 681 calculates the values ​​of height b and distance D for calculating position correction information based on the sizes of portions 31c, 31d, and 32c detected as parameter information, for example, by referring to a pre-set data table. In the pre-set data table, the sizes of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32 of the subject 201, the height b from the detection surface to the lateral condyle 31b, and the actual distance D between the medial condyle 31a and the lateral condyle 31b are stored in association. That is, the processing unit 681 calculates the height b and distance D, which are inherent to the physical characteristics of the subject 201, by acquiring the sizes of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32 of the subject 201 detected as parameter information.

[0122] The processing unit 681 calculates the value of the tilt angle α using the height b and distance D obtained in this way, according to the above formula (2). Furthermore, regarding the angle θ, which is a parameter derived from posture, a recommended value can be automatically set based on the body part being photographed, or the value can be detected by detecting the posture of the subject 201 using an optical camera or the like. Then, the processing unit 681 uses the tilt angle α, which reflects the parameter derived from the physique, to calculate the estimated position x' using the above formula (1), thereby calculating position correction information corresponding to the different bone sizes and shapes for each subject 201.

[0123] Furthermore, the other structures of the X-ray imaging apparatus 600 in the second embodiment are the same as those in the first embodiment. That is, the acquisition of the pre-captured image 24, the acquisition of the offset f1 from the pre-captured image 24, and the processing of position correction based on the calculated position correction information are the same as in the first embodiment.

[0124] (Photography position correction method according to the second embodiment)

[0125] Next, refer to Figure 22 The processing flow of the imaging position correction method of the X-ray imaging apparatus 600 in the second embodiment will be described. Figure 22 The document describes the processing flow for position correction using the automatic correction mode.

[0126] First, in steps 701 and 702, the same processes as steps 301 and 302 of the first embodiment are performed, respectively. Then, after step 702 is completed, the processing steps proceed to step 703. Furthermore, step 701 is an example of the "irradiation step" of this disclosure. Additionally, step 702 is an example of the "detection step" of this disclosure.

[0127] In step 703, parameter information corresponding to the actual distance between the medial condyle 31a and the lateral condyle 31b (multiple specified portions) of the bone (photographic object) of the subject 201 is obtained. Specifically, as parameter information, the size of each portion (detection object portion) of the femur 31 (parts 31c and 31d) and the tibia 32 (parts 32c) is detected from the pre-captured image 24 captured in step 702.

[0128] Then, in step 704, position correction information is calculated based on the parameter information. Specifically, height b and distance D are obtained based on the sizes of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32, which are obtained as parameter information. Then, tilt α is calculated based on the obtained height b and distance D, thereby obtaining position correction information based on the offset (positional relationship between the outer edges of the plurality of defined portions) obtained from the pre-captured image 24. Furthermore, step 704 is an example of the "correction information acquisition step" of this disclosure.

[0129] Then, in step 705, automatic position correction is performed in the same manner as in step 304 of the first embodiment. Furthermore, step 704 is an example of the "position correction step" of this disclosure.

[0130] Furthermore, when performing position correction processing using the manual correction mode, similarly to the first embodiment, after obtaining position correction information by performing the same processing as steps 701, 702, 703 and 704 in the automatic correction mode, the position correction information is displayed in the same way as step 404 in the first embodiment, and manual position correction is performed in the same way as step 405.

[0131] (Effects of the second implementation method)

[0132] In the second embodiment, the following effects can be obtained.

[0133] The processing unit 681 (correction information acquisition unit) is configured to calculate position correction information based on parameter information corresponding to the actual distances between multiple predetermined portions (medial condyle 31a and lateral condyle 31b) of the bone (the object of radiography) of the subject 201. With this configuration, even when the actual distances between the predetermined portions of the bone of the subject 201 differ due to variations in bone size and shape for each subject 201, the position correction information can be calculated more accurately by using parameter information corresponding to the actual distances between the predetermined portions. Therefore, the acquired position correction information can be used to correct the radiographic position with higher precision, thereby further reducing the number of times X-ray images are repeatedly taken and the radiographic position corrected. As a result, the increase in radiation dose and radiographic time during X-ray radiography can be further suppressed.

[0134] The processing unit 681 (correction information acquisition unit) detects the size of the target portions of the subject 201 (parts 31c and 31d of the femur 31 and part 32c of the tibia 32) in the X-ray image of the subject 201, and uses this as parameter information. If configured in this way, by detecting the size of the target portions from the X-ray image of the subject 201 and using this as parameter information, parameter information can be acquired in a way that more accurately reflects the differences in size and shape between the femur 31 and tibia 32, which are internal structures of the subject 201. Therefore, by acquiring position correction information using the parameter information detected from the X-ray image of the subject 201, the relative direction and amount of relative movement required to correct the imaging position can be acquired more accurately. As a result, the imaging position can be corrected more accurately.

[0135] The processing unit 681 (correction information acquisition unit) detects the size of the target portion of the subject 201 (parts 31c and 31d of the femur 31 and part 32c of the tibia 32) from the X-ray image 24, which is taken to acquire position correction information, and uses this size as parameter information. With this configuration, parameter information can be acquired using the pre-image 24 taken to acquire position correction information. Therefore, unlike the case where X-ray imaging is performed separately from the pre-image 24 for acquiring parameter information, the increase in X-ray dose irradiated to the subject 201 can be suppressed. Thus, by acquiring parameter information from the pre-image 24, the imaging position can be corrected more accurately, and the increase in radiation dose and imaging time during X-ray imaging can be further suppressed.

[0136] Furthermore, the other effects of the second embodiment are the same as those of the first embodiment described above.

[0137] [Third Implementation Method]

[0138] Reference Figure 23 and Figure 24 The third embodiment will be described. In this third embodiment, unlike the second embodiment where the processing unit 681 detects the size of the target portion (parts 31c and 31d of the femur 31 and part 32c of the tibia 32) of the subject 201 from the pre-captured image 24 as parameter information for setting the tilt angle α, the parameter information for setting the tilt angle α is obtained based on the appearance image 25. Furthermore, in the figures, parts with the same structure as those in the first and second embodiments are labeled with the same reference numerals.

[0139] (Structure of the X-ray imaging apparatus according to the third embodiment)

[0140] like Figure 23 As shown, the X-ray imaging apparatus 800 includes a processing unit 808. The processing unit 808 includes a processing section 881. Similar to the processing unit 608 of the second embodiment, the processing unit 808 is, for example, a PC operated by a user 202 such as a radiographer. Similar to the processing section 681 of the second embodiment, the processing section 881 includes a CPU, a GPU, and RAM. The processing section 881 is an example of the "correction information acquisition section" of this disclosure. Similar to the processing section 681 of the second embodiment, the processing section 881 automatically calculates the tilt angle α using the above formula (2). In the third embodiment, for example, X-ray imaging of the knee of the subject 201 is performed by the X-ray imaging apparatus 800.

[0141] In the third embodiment, the X-ray imaging apparatus 800 includes an imaging unit 811 and an image processing unit 812. The imaging unit 811 captures the appearance of the subject 201. The imaging unit 811 is, for example, disposed in the X-ray irradiation unit 1. The imaging unit 811 captures the appearance of the subject 201 lying on the top plate 3 along the irradiation direction of the X-rays irradiated from the X-ray irradiation unit 1. In addition, the imaging unit 811 includes, for example, an image sensor (imaging element) such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The image processing unit 812 includes, for example, a processor such as a CPU or an FPGA. In addition, the image processing unit 812 includes a non-volatile storage medium such as an HDD or SSD for storing various parameters and programs. The image processing unit 812 acquires an appearance image 25 (see reference) of the subject 201 obtained by acquiring signals from the imaging unit 811. Figure 24 The image processing unit 812 is a module separate from the processing unit 881. For example, the image processing unit 812 is disposed together with the camera unit 811 in the X-ray irradiation unit 1. Furthermore, the image processing unit 812 is configured to communicate with the processing unit 881.

[0142] Then, as Figure 24 As shown, in the third embodiment, the image processing unit 812 calculates body information representing the size of the subject 201 based on the appearance image 25 of the subject 201 acquired by the camera unit 811, and uses this information as parameter information for calculating the tilt angle α in the above formula (2). Specifically, the image processing unit 812 calculates the length of the subject 201's legs as body information. The image processing unit 812 detects the lengths of portions 201a and 201b of the subject 201's legs from the appearance image 25 acquired based on the signal from the camera unit 811. Portion 201a is the portion from the root of the subject 201's leg to the knee. Portion 201b is the portion from the knee of the subject 201's leg to the toes. The image processing unit 812, for example, uses a learned model pre-stored in a storage medium to extract portions 201a and 201b of the leg of the subject 201 from the appearance image 25, thereby detecting the length of portions 201a and 201b. Thus, the image processing unit 812 detects physical information representing the length of the leg of the subject 201 from the appearance image 25 as parameter information.

[0143] Then, similarly to the processing unit 681 in the second embodiment, the image processing unit 812 calculates the values ​​of height b and distance D for calculating position correction information by referring to a data table pre-set in the storage medium, based on body information representing the length of the legs of the subject 201 detected as parameter information. In the pre-set data table, the body information, the height b from the detection surface to the lateral condyle 31b, and the actual distance D between the medial condyle 31a and the lateral condyle 31b are stored in association. That is, in the third embodiment, the image processing unit 812 calculates the height b and distance D, which are inherent to the body of the subject 201, by acquiring the body information as parameter information. Furthermore, in the third embodiment, the height b and distance D calculated by the image processing unit 812 are output to the processing unit 881 of the processing device 808.

[0144] Using the height b and distance D obtained in this way, the processing unit 881, like the processing unit 681 in the second embodiment, calculates the value of the tilt angle α using the above formula (2), and calculates the estimated position x' using the above formula (1), thereby calculating position correction information corresponding to the size and shape of the bones that vary for each subject 201. That is, in the third embodiment, the processing unit 881 is configured to calculate the position correction information based on the body information, i.e., parameter information, calculated by the image processing unit 812 from the appearance image 25.

[0145] Furthermore, the other structures of the X-ray imaging apparatus 800 in the third embodiment are the same as those in the first and second embodiments described above.

[0146] (Effects of the third implementation method)

[0147] In the third embodiment, the following effects can be obtained.

[0148] In the third embodiment, an imaging unit 811 is included to capture the appearance of the subject 201. Furthermore, a processing unit 881 (correction information acquisition unit) calculates position correction information based on body information, i.e., parameter information, representing the body size of the subject 201, calculated from the appearance image 25 of the subject 201 acquired by the imaging unit 811. With this configuration, body information, i.e., parameter information, representing the body size of the subject 201 can be acquired based on the appearance image 25, thus enabling the acquisition of position correction information corresponding to the body size of the subject 201. Therefore, the relative movement direction and relative movement amount required for correcting the imaging position can be acquired more accurately in a manner corresponding to the body size of the subject 201, thereby enabling more accurate correction of the imaging position.

[0149] Furthermore, the other effects of the third embodiment are the same as those of the first and second embodiments described above.

[0150] [Fourth Implementation Method]

[0151] Reference Figure 25 and Figure 26 The fourth embodiment will be described. In this fourth embodiment, unlike the second embodiment where the processing unit 681 acquires parameter information from the pre-captured image 24, the processing unit 981 acquires parameter information for setting the tilt angle α based on the frontal image 26, which is an X-ray image acquired separately from the pre-captured image 24. Furthermore, in the figures, portions with the same structure as those in the first to third embodiments are labeled with the same reference numerals.

[0152] (Structure of the X-ray imaging apparatus according to the fourth embodiment)

[0153] like Figure 25As shown, the X-ray imaging apparatus 900 includes a processing unit 908. The processing unit 908 includes a processing section 981. Similar to the processing unit 608 of the second embodiment, the processing unit 908 is, for example, a PC operated by a user 202 such as a radiographer. Similar to the processing section 681 of the second embodiment, the processing section 981 includes a CPU, a GPU, and RAM. Similar to the processing section 681 of the second embodiment, the processing section 981 automatically calculates the tilt angle α using the above formula (2). Furthermore, the processing section 981 is an example of the "correction information acquisition section" of this disclosure. In the fourth embodiment, for example, X-ray imaging of the knee of the subject 201 is performed by the X-ray imaging apparatus 900.

[0154] like Figure 26 As shown, in the fourth embodiment, the processing unit 981 acquires a frontal image 26, which is an X-ray image taken from a different photographic angle than the pre-taken image 24, which is an X-ray image used to acquire position correction information. Then, the processing unit 981 detects the size of the detection target portion of the subject 201 from the frontal image 26, and uses it as parameter information for calculating the tilt angle α. Specifically, the frontal image 26 is an X-ray image of the knee of the subject 201 taken from the front side, separate from the pre-taken image 24 obtained by taking a picture of the knee of the subject 201 from the side. The frontal image 26 is taken at a time earlier than the pre-taken image 24 and stored in the storage unit 82 in advance. Moreover, the detection target portion of the subject 201 detected from the frontal image 26 is the portion 31e of the femur 31 of the subject 201 from the medial condyle 31a to the lateral condyle 31b, and the portion 31f from the lateral condyle 31b to the skin on the side of the subject 201 opposite to the midline side. Therefore, in the fourth embodiment, the detection object portion of the test subject 201 whose size is detected as parameter information is a plurality of predetermined portions of the photographic object of the test subject 201, which are objects photographed in a predetermined positional relationship.

[0155] Before taking the pre-captured image 24, the processing unit 981 detects the positions of the medial condyle 31a and the lateral condyle 31b from the pre-captured frontal image 26. For example, the processing unit 981 extracts the contour of the femur 31 through segmentation processing based on a pre-stored learned model, and detects the portion of the extracted femur 31 contour line closest to the tibia 32 at the medial condyle 31a and the portion closest to the tibia 32 at the lateral condyle 31b as the positions of the medial condyle 31a and the lateral condyle 31b, respectively. Then, the processing unit 981 detects the size (distance) from the position of the medial condyle 31a to the position of the lateral condyle 31b as the size of the detection target portion, i.e., portion 31e, of the subject 201. Similarly, the processing unit 981 detects the position of the skin of the subject 201 in the frontal image 26, and determines the size of the detection target portion, i.e., portion 31f, of the subject 201 by measuring the distance from the position of the lateral condyle 31b to the position of the skin. Here, the size of portion 31e corresponds to the actual distance D between the medial condyle 31a and the lateral condyle 31b. Furthermore, the size of portion 31f corresponds to the height b from the detection surface to the lateral condyle 31b. That is, in the fourth embodiment, the processing unit 981 directly detects the values ​​of height b and distance D from the frontal image 26, which is captured separately from the pre-captured image 24, as parameter information.

[0156] Then, similarly to the processing unit 681 in the second embodiment, the processing unit 981 uses the height b (size of part 31f) from the detection surface to the lateral condyle 31b and the actual distance D (size of part 31e) between the medial condyle 31a and the lateral condyle 31b detected as parameter information to calculate the value of the inclination α using the above formula (2), and calculates the estimated position x' using the above formula (1), thereby calculating the position correction information corresponding to the different bone size and shape for each subject 201.

[0157] Furthermore, the other structures of the X-ray imaging apparatus 900 in the fourth embodiment are the same as those in the first to third embodiments described above.

[0158] (Effects of the fourth implementation method)

[0159] In the fourth embodiment, the following effects can be obtained.

[0160] The processing unit 981 (correction information acquisition unit) detects the size of the target portion (parts 31e and 31f) of the subject 201 from the frontal image 26 as parameter information. This frontal image 26 is an X-ray image pre-captured from a different imaging angle than the pre-captured image 24, which is used to acquire position correction information. If configured in this way, by detecting the size of the target portion from the X-ray image (frontal image 26) captured from a different imaging angle than the pre-captured image 24 used for position correction, the positional relationship between multiple specified portions (medial condyle 31a and lateral condyle 31b) viewed from a different imaging angle than the pre-captured image 24 can be detected. Therefore, more accurate position correction information can be obtained based on the positional relationship between multiple specified portions viewed from a different imaging angle than the pre-captured image 24.

[0161] Furthermore, the other effects of the fourth embodiment are the same as those of the first to third embodiments described above.

[0162] [Variation Example]

[0163] Furthermore, the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the invention is shown not by the description of the above embodiments but by the claims. All modifications (variations) in the same sense and scope as the claims are also included.

[0164] For example, in the first to fourth embodiments described above, the following example is shown: the processing units 81, 681, 881, and 981 (correction information acquisition units) are configured to acquire position correction information for correcting the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201 based on the positional relationship between the outer edges of multiple predetermined portions of the bone in the X-ray image. However, the present invention is not limited to this. In the present invention, the correction information acquisition unit may also be configured to acquire position correction information for correcting the relative position of the X-ray irradiation unit relative to the artificial joint of the subject based on the positional relationship between the outer edges of multiple predetermined portions of an artificial joint in the X-ray image. Furthermore, the correction information acquisition unit of the X-ray imaging apparatus may also be configured to acquire position correction information both when imaging the bone and when imaging the artificial joint. In addition, the artificial joint is an example of the "imaging object" of this disclosure.

[0165] Furthermore, the first to fourth embodiments described above illustrate examples of displaying position correction information acquired by processing units 81, 681, 881, and 981 (correction information acquisition units) and controlling the change of the relative position of the X-ray irradiation unit 1 with respect to the bones of the subject 201 based on the position correction information; however, the present invention is not limited to these examples. In the present invention, the X-ray imaging apparatus may also only notify the user of the position correction information acquired by the correction information acquisition unit. In this case, the user, such as a radiologist, manually corrects the imaging position based on the notified position correction information. Additionally, the correction of the relative position of the X-ray irradiation unit with respect to the bones or artificial joints (the object of imaging) of the subject can also be performed by the user moving the subject or by moving the subject. Furthermore, the X-ray imaging apparatus may also be configured to automatically correct the imaging position without notifying the user of the position correction information acquired by the correction information acquisition unit.

[0166] Furthermore, in the first to fourth embodiments described above, the following example is shown: the device control unit 7 (movement control unit) automatically moves the position of the X-ray irradiation unit 1 based on the position correction information acquired by the processing units 81, 681, 881, and 981 (correction information acquisition unit), so that the relative position of the X-ray irradiation unit 1 with respect to the bone of the subject 201 is such that an X-ray image can be captured showing the positional relationship between the outer edges of multiple predetermined parts in a predetermined positional relationship. However, the present invention is not limited to this. In the present invention, when correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint (the object of imaging) of the subject, the imaging position can also be corrected by automatically moving both the X-ray irradiation unit and the top plate on which the subject is placed. In addition, when correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint (the object of imaging) of the subject, the imaging position can also be corrected by automatically moving only the top plate on which the subject is placed.

[0167] Furthermore, in the first to fourth embodiments described above, the following example is shown: when the X-ray irradiation unit 1 is moved based on the operation of the user 202, the device control unit 7 (movement control unit) performs control to limit the movement of the X-ray irradiation unit 1 based on the position correction information obtained by the processing units 81, 681, 881, and 981 (correction information acquisition unit), but the present invention is not limited to this. In the present invention, the X-ray imaging apparatus may also be configured such that the movement restriction of the X-ray irradiation unit is not performed when the user is operating. In addition, the X-ray imaging apparatus may also be configured to limit the movement of the X-ray irradiation unit and release the movement restriction based on the user's operation. In addition, in the present invention, when the top plate on which the subject is placed is moved based on the operation of the user, the movement control unit may also perform control to limit the movement of the top plate on which the subject is placed based on the position correction information obtained by the correction information acquisition unit. For example, the movement control unit may also limit the movement of the top plate by the movement mechanism by locking the movement of the top plate by a brake. Therefore, even when the imaging position is corrected by moving the top plate on which the subject is placed manually by the user, the movement control unit can limit the movement of the top plate on which the subject is placed based on the position correction information. As a result, when the imaging position is corrected by moving the top plate on which the subject is placed manually by the user, it is possible to prevent the top plate on which the subject is placed from moving by more than the amount of movement required for correction, and to prevent the top plate on which the subject is placed from moving in a direction other than the direction of movement required for correction.

[0168] Furthermore, in the first to fourth embodiments described above, the following example is shown: the display unit 91 is configured to display the relative movement direction and relative movement amount of the X-ray irradiation unit 1 relative to the bone of the subject 201, based on the relative positional offset between the outer edges of a plurality of predetermined portions obtained by the processing units 81, 681, 881, and 981 (correction information acquisition units), as a notification of the position correction information obtained by the processing units 81 (681, 881, and 981), but the present invention is not limited thereto. In the present invention, the display unit may also display only the relative movement direction of the X-ray irradiation unit among the relative movement direction and relative movement amount of the X-ray irradiation unit relative to the bone of the subject. In this case, when the X-ray irradiation unit, moved by the user's manual operation, reaches the appropriate imaging position obtained based on the position correction information, the X-ray imaging apparatus completes the imaging position correction by restricting (locking) the movement of the X-ray irradiation unit.

[0169] Furthermore, in the first to fourth embodiments described above, the following example was shown: when photographing the knee joint (the knee side of the femur 31), the relative position of the X-ray irradiation unit 1 with respect to the bone or artificial joint (the object being photographed) of the subject 201 was corrected according to position correction information to a position where an X-ray image of multiple predetermined portions overlapping each other could be captured. However, the present invention is not limited to this. In the present invention, it is also possible to... Figure 17 As shown, when the scapula 39 is photographed in a Y-shape, known as the scapula Y, positional correction information is acquired to correct the imaging position so that the outer edges of multiple specified portions of the scapula 39 overlap and the scapula 39 appears as a Y-shape in the X-ray image. Furthermore, the relative position of the X-ray irradiation area to the subject can be corrected based on the acquired positional correction information. Thus, X-ray images that can be acquired with high precision to determine diseases around the scapula 39, such as anterior dislocation, subacromial osteophytes, and calcification.

[0170] Furthermore, in the first to fourth embodiments described above, the following examples were shown: when the X-ray imaging apparatus 100 (600, 800, 900) was imaging the knee joint (knee side of the femur 31) and the elbow joint (knee side of the humerus 36), it calculated position correction information and corrected the imaging position based on the position correction information; however, the present invention is not limited thereto. In the present invention, the X-ray imaging apparatus may also be configured to calculate position correction information and correct the imaging position based on the position correction information when imaging other joints and other parts such as the hip joint, finger joints, wrist joints, and ankle joints.

[0171] Furthermore, in the first to fourth embodiments described above, the following example was shown: the X-ray imaging apparatus 100 (600, 800, 900) acquires position correction information when imaging the knee joint (knee side of the femur 31) and the elbow joint (elbow side of the humerus 36), displays (notifies) the acquired position correction information, and controls the relative position of the X-ray irradiation unit 1 based on the acquired position correction information; however, the present invention is not limited thereto. In the present invention, the X-ray imaging apparatus may also be configured to acquire position correction information only when imaging the knee joint (knee side of the femur) and when imaging the elbow joint (elbow side of the humerus), and notify the acquired position correction information or control the relative position of the X-ray irradiation unit based on the acquired position correction information. That is, the X-ray imaging apparatus may also acquire position correction information only for a specific imaging site and notify the acquired position correction information or control the relative position of the X-ray irradiation unit based on the acquired position correction information.

[0172] Furthermore, in the first to fourth embodiments described above, the following example is shown: the processing units 81, 681, 881, and 981 (correction information acquisition units) are configured to acquire position correction information based on the positional relationship between the outer edges of multiple predetermined portions of the bone of the subject 201 in the pre-captured image 24 (image before position correction). This pre-captured image 24 is an image generated based on X-ray irradiation with a radiation dose less than that used when capturing the formal irradiation image 23 (image after position correction). The formal irradiation image 23 is an image captured after correcting the relative position of the X-ray irradiation unit 1 relative to the bone of the subject 201. However, the present invention is not limited to this. In the present invention, the image used by the correction information acquisition unit to acquire position correction information may also be an X-ray image generated based on X-ray irradiation with a radiation dose greater than that used when capturing the image after position correction, after correcting the relative position of the X-ray irradiation unit. In addition, the image used by the correction information acquisition unit to acquire the position correction information may also be an X-ray image generated by irradiation with X-rays of a radiation dose greater than the radiation dose when the position correction image is taken after the relative position of the X-ray irradiation unit has been corrected, and then preprocessed as described in the first to fourth embodiments above.

[0173] Furthermore, in the first to fourth embodiments described above, the following example is shown: the processing units 81, 681, 881, and 981 (correction information acquisition units) are configured to input X-ray images to the learned models 82a and 82b, thereby acquiring the outer edges of multiple predetermined portions based on the input X-ray images, and calculating position correction information based on the acquired outer edges of the multiple predetermined portions. However, the present invention is not limited to this. In the present invention, the acquisition (determination) of the outer edges of multiple predetermined portions used for calculating offsets, such as the medial and lateral condyles of the femur, can also be achieved using an image processing algorithm such as extracting feature points from the outer edges of the multiple predetermined portions. In addition, when acquiring parameter information for acquiring parameters inherent to the subject derived from the physical characteristics, the learned model may not be used, and an image processing algorithm such as extracting feature points may be used instead.

[0174] Furthermore, in the first to fourth embodiments described above, the following example was shown: the processing units 81, 681, 881, and 981 (correction information acquisition units) were configured to acquire the outer edges of multiple predetermined portions based on the input X-ray image, and to calculate position correction information based on the acquired outer edges of the multiple predetermined portions; however, the present invention is not limited thereto. In the present invention, the correction information acquisition unit may, in addition to using X-ray images, also use visible light images of the subject captured by an optical camera that detects visible light when acquiring the outer edges of multiple predetermined portions of the bone or artificial joint (the object of radiography) of the subject and calculating position correction information.

[0175] Furthermore, the first to fourth embodiments described above show examples of X-ray imaging apparatus 100 (600, 800, 900) configured to switch between automatic and manual correction modes based on user 202's switching operation, but the present invention is not limited thereto. In the present invention, the imaging position correction using the X-ray imaging apparatus may also perform only one of automatic or manual correction.

[0176] Furthermore, the first to fourth embodiments described above illustrate examples where the X-ray imaging apparatus 100 (600, 800, 900) is configured to take X-ray images using X-rays irradiated by an X-ray irradiation unit 1 suspended from the ceiling, but the present invention is not limited thereto. The present invention can also be applied to, for example... Figure 18 The X-ray imaging apparatus 500, as shown, includes an irradiation unit support mechanism 504 extending in a direction intersecting the ground (Z direction) and an X-ray irradiation unit 501 supported by the irradiation unit support mechanism 504. That is, the X-ray imaging apparatus can also be configured to take X-ray images by irradiating X-rays from the X-ray irradiation unit 501 installed in the irradiation unit support mechanism 504 extending in a direction intersecting the ground (Z direction). Furthermore, in the imaging position correction using the X-ray imaging apparatus 500, such as... Figure 19 Position correction information is displayed on the display unit 591 of the operation terminal 509 as shown, and the camera position is corrected by manual operation of the user 202. In addition, a touch panel for receiving input operations from the user 202 is provided on the display unit 591 of the operation terminal 509.

[0177] Furthermore, the second to fourth embodiments described above illustrate an example of calculating the tilt angle α, a coefficient used for calculating position correction information, based on automatically acquired parameter information; however, the present invention is not limited to this. In the present invention, parameter information can also be acquired based on input operations performed by the user. Alternatively, the parameter information can be calculated from X-ray images or appearance images by a processing device different from the processing units 681, 881, and 981 (correction information acquisition units) that calculate position correction information. Additionally, pre-set (stored) parameter information can be acquired from an external device such as a server. Furthermore, the parameter information may also include values ​​of inherent parameters of the subject (height b and distance D, etc.) used for calculating position correction information.

[0178] Furthermore, in the second embodiment described above, the following example is shown: as parameter information, the sizes of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32 of the subject 201 are detected as the size of the target portion of the subject 201, but the present invention is not limited thereto. In the present invention, the size of at least one portion of portions 31c and 31d of the femur 31 and portion 32c of the tibia 32 may also be obtained as parameter information. Additionally, in the case of X-ray imaging of the knee, the sizes of portions other than portions 31c, 31d, and 32c may be detected as the size of the target portion of the subject.

[0179] Furthermore, in the third embodiment described above, an example was shown of obtaining physical information representing the length of the legs of the subject 201 as parameter information, but the present invention is not limited to this. In the present invention, the height of the entire body of the subject can also be detected, and physical information representing the detected height of the subject can be obtained as parameter information. Additionally, in the case of performing an X-ray of the elbow joint, physical information representing the length of the arm can be obtained as parameter information. Furthermore, physical information representing shoulder width, body thickness, etc., can also be obtained as parameter information. Furthermore, in the third embodiment described above, an example was shown where the processing of obtaining parameter information from the appearance image 25 is performed by an image processing unit 812, a module different from the processing unit 881 (correction information acquisition unit) that performs position correction information calculation. However, the appearance image obtained by the imaging unit can also be output to the correction information acquisition unit, whereby the correction information acquisition unit detects physical information from the appearance image to obtain parameter information.

[0180] Furthermore, the third embodiment described above illustrates an example where the camera unit 811, disposed in the X-ray irradiation unit 1, photographs the subject 201 lying on the ceiling 3, but the present invention is not limited thereto. In the present invention, the camera unit may not be disposed in the X-ray irradiation unit, but rather in the ceiling portion of the examination room, etc. Alternatively, instead of photographing the subject lying on the ceiling, parameter information may be obtained by photographing the subject in a standing position.

[0181] Furthermore, in the first to fourth embodiments described above, for ease of explanation, a process-driven flowchart illustrating the imaging position correction (automatic and manual correction) of the X-ray imaging apparatus using the present invention was used, where processes are executed sequentially according to a processing flow. However, the present invention is not limited thereto. In the present invention, the imaging position correction process using the X-ray imaging apparatus can also be performed using an event-driven type of processing that executes processing on an event-by-event basis. In this case, it can be performed entirely as an event-driven process, or a combination of event-driven and process-driven processes can be used.

[0182] [project]

[0183] Those skilled in the art will understand that the above exemplary embodiments are specific examples of the following methods.

[0184] (Project 1)

[0185] An X-ray imaging device, comprising:

[0186] The X-ray irradiation section irradiates the subject with X-rays.

[0187] An X-ray detection unit that detects X-rays that have irradiated and passed through the subject from the X-ray irradiation unit; and

[0188] The correction information acquisition unit determines the outer edges of multiple predetermined portions of a radiographic object of the subject in an X-ray image captured based on the detection signal of the X-ray detection unit, and acquires position correction information for correcting the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the determined positional relationship between the outer edges of the multiple predetermined portions.

[0189] The position correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation section with respect to the radiographic object of the subject so that the positional relationship between the outer edges of the plurality of specified parts can be captured in the X-ray image that reflects the specified positional relationship.

[0190] (Project 2)

[0191] According to the X-ray imaging apparatus described in Project 1, wherein...

[0192] The X-ray imaging apparatus is configured to perform at least one of the following processes: notifying the position correction information acquired by the correction information acquisition unit; and controlling the relative position of the X-ray irradiation unit with respect to the imaging object of the subject based on the position correction information.

[0193] (Project 3)

[0194] The X-ray imaging apparatus according to Project 2 further comprises:

[0195] A moving mechanism that changes the relative position of the X-ray irradiation unit with respect to the subject; and

[0196] The movement control unit controls the movement mechanism to change the relative position of the X-ray irradiation unit with respect to the subject.

[0197] The movement control unit is configured to control the movement mechanism to change the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the position correction information obtained by the correction information acquisition unit.

[0198] (Project 4)

[0199] According to the X-ray imaging apparatus described in Project 3, wherein...

[0200] It also has a top plate for placing the subject of the test.

[0201] The movement control unit controls the automatic movement of at least one of the X-ray irradiation unit and the top plate based on the position correction information obtained by the correction information acquisition unit, so that the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject is such that the X-ray image can be captured based on the positional relationship between the outer edges of the plurality of specified parts.

[0202] (Project 5)

[0203] According to the X-ray imaging apparatus described in Project 3, wherein...

[0204] It also has a top plate for placing the subject of the test.

[0205] When the user moves one of the X-ray irradiation unit and the top plate, the movement control unit performs control to limit the movement of one of the X-ray irradiation unit and the top plate based on the position correction information obtained by the correction information acquisition unit.

[0206] (Project 6)

[0207] The X-ray imaging apparatus according to any one of items 2 to 5, wherein...

[0208] It also includes a display unit that displays at least the relative movement direction of the X-ray irradiation unit, which is used to correct the position of the X-ray image reflected by the positional relationship between the outer edges of the plurality of predetermined parts in order to capture the position of the X-ray image reflected by the predetermined positional relationship, as a notification of the position correction information acquired by the correction information acquisition unit.

[0209] (Project 7)

[0210] The X-ray imaging apparatus according to any one of items 2 to 6, wherein...

[0211] The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the multiple specified parts of the X-ray image based on the positional relationship between the outer edges of the multiple specified parts of the subject in the X-ray image, and acquire the position correction information based on the acquired relative positional offset between the outer edges of the multiple specified parts.

[0212] (Project 8)

[0213] The X-ray imaging apparatus according to any one of items 2 to 7, wherein...

[0214] The correction information acquisition unit is configured to: determine the outer edges of each of the plurality of predetermined portions of the bone or artificial joint in the X-ray image, which are the radiographic objects of the subject, and acquire position correction information for correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint of the subject based on the determined positional relationship between the outer edges of the plurality of predetermined portions of the bone or artificial joint.

[0215] (Project 9)

[0216] According to the X-ray imaging apparatus described in Project 8, wherein...

[0217] The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the plurality of specified portions based on the overlap between the outer edges of the bone or artificial joint of the subject in the X-ray image, and calculate the positional correction information for correcting the relative position of the X-ray irradiation unit relative to the bone or artificial joint of the subject to a position in which the X-ray image is captured with the outer edges of the plurality of specified portions overlapping each other.

[0218] (Project 10)

[0219] According to the X-ray imaging apparatus described in Project 9, wherein...

[0220] The correction information acquisition unit is configured to: when taking an image of at least one of the femur on the knee side and the scapula of the subject, calculate position correction information for correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint of the subject to a position in which the X-ray image of the outer edges of the plurality of predetermined parts overlaps with each other.

[0221] (Project 11)

[0222] The X-ray imaging apparatus according to any one of items 8-10, wherein,

[0223] The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the plurality of specified portions based on the positional relationship between the outer edges of the bones or artificial joints of the subject in the X-ray image, and calculate the positional correction information for correcting the relative position of the X-ray irradiation unit relative to the bones or artificial joints of the subject to a position that can capture the X-ray image in which the outer edges of the plurality of specified portions are concentrically reflected.

[0224] (Project 12)

[0225] According to the X-ray imaging apparatus described in Project 11, wherein...

[0226] The correction information acquisition unit is configured to: when taking an image of the elbow side of the humerus of the subject, calculate position correction information for correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint of the subject to a position that can capture the X-ray image of the outer edges of the plurality of specified portions in a concentric circle.

[0227] (Project 13)

[0228] The X-ray imaging apparatus according to any one of items 1 to 12, wherein,

[0229] The correction information acquisition unit is configured to acquire the position correction information based on the positional relationship between the outer edges of the plurality of predetermined portions of the radiographic object of the subject in the image before position correction. The image before position correction is generated based on X-ray irradiation with a radiation dose less than that when the image after position correction is taken. The image after position correction is the X-ray image taken after the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject has been corrected.

[0230] (Project 14)

[0231] The X-ray imaging apparatus according to any one of items 1 to 13, wherein,

[0232] The correction information acquisition unit is configured to: input a learned model obtained by machine learning from the X-ray image of the photographic object as input data into the X-ray image, thereby acquiring the outer edges of the plurality of predetermined parts based on the input X-ray image, and calculating the position correction information based on the acquired outer edges of the plurality of predetermined parts.

[0233] (Project 15)

[0234] The X-ray imaging apparatus according to any one of items 1 to 14, wherein,

[0235] The correction information acquisition unit is configured to calculate the position correction information based on parameter information corresponding to the actual distance between the multiple specified parts of the photographic object of the subject.

[0236] (Project 16)

[0237] According to the X-ray imaging apparatus described in Project 15, wherein...

[0238] The correction information acquisition unit detects the size of the detection object portion of the subject in the X-ray image of the subject, and uses it as the parameter information.

[0239] (Project 17)

[0240] According to the X-ray imaging apparatus described in Project 16, wherein...

[0241] The correction information acquisition unit detects the size of the detection object portion of the subject from the X-ray image taken in order to acquire the position correction information, and uses this as the parameter information.

[0242] (Project 18)

[0243] According to the X-ray imaging apparatus described in Project 16, wherein...

[0244] The correction information acquisition unit detects the size of the target portion of the subject from an X-ray image taken from a different photographic angle than the X-ray image used to acquire the position correction information, and uses this as the parameter information.

[0245] (Project 19)

[0246] According to the X-ray imaging apparatus described in Project 15, wherein...

[0247] It also has a camera unit for capturing images of the appearance of the subject being examined.

[0248] The correction information acquisition unit is configured to calculate the position correction information based on the parameter information, which is physical information, and the physical information is information representing the size of the subject's body, calculated from the appearance image of the subject acquired by the camera unit.

[0249] (Project 20)

[0250] A method for correcting photographic position includes the following steps:

[0251] The irradiation procedure involves irradiating the subject with X-rays from the X-ray irradiation unit.

[0252] The detection steps include detecting X-rays that have penetrated the subject; and

[0253] The correction information acquisition step involves determining the outer edges of multiple predetermined portions of a radiographic object of the subject in the X-ray image captured based on the X-ray detection in the detection step, and acquiring position correction information for correcting the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the determined positional relationship between the outer edges of the multiple predetermined portions.

[0254] The position correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation section with respect to the radiographic object of the subject so that the positional relationship between the outer edges of the plurality of specified parts can be captured in the X-ray image that reflects the specified positional relationship.

[0255] (Project 21)

[0256] According to the photographic position correction method described in Project 20, wherein,

[0257] It also includes a position correction step, in which at least one of the following processes is performed: notifying the position correction information obtained in the correction information acquisition step, and controlling the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the position correction information.

[0258] (Project 22)

[0259] According to the photographic position correction method described in item 20 or 21, wherein,

[0260] The correction information acquisition step includes a correction information acquisition step that calculates the position correction information based on parameter information corresponding to the actual distance between the multiple specified parts of the photographic object of the subject.

Claims

1. An X-ray imaging device, comprising: The X-ray irradiation section irradiates the subject with X-rays. An X-ray detection unit that detects X-rays that have irradiated and passed through the X-ray irradiation unit onto the subject; and The correction information acquisition unit determines the outer edges of multiple predetermined portions of a radiographic object of the subject based on the X-ray image captured by the X-ray detection unit, and acquires positional correction information based on the determined positional relationship between the outer edges of the multiple predetermined portions of the radiographic object to correct the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject, such that the outer edges of the multiple predetermined portions of the radiographic object at least partially overlap each other. The radiographic object is a bone or artificial joint of the subject. in, The position correction information includes the relative direction and amount of movement for correcting the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject so that the positional relationship between the outer edges of the plurality of specified portions of the radiographic object can be captured as a specified positional relationship in the X-ray image.

2. The X-ray imaging apparatus according to claim 1, characterized in that, The X-ray imaging apparatus is configured to perform at least one of the following processes: notifying the position correction information acquired by the correction information acquisition unit; and controlling the relative position of the X-ray irradiation unit with respect to the imaging object of the subject based on the position correction information.

3. The X-ray imaging apparatus according to claim 2, characterized in that, It also has: A moving mechanism that changes the relative position of the X-ray irradiation unit with respect to the subject; and The movement control unit controls the movement mechanism to change the relative position of the X-ray irradiation unit with respect to the subject. The movement control unit is configured to control the movement mechanism to change the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the position correction information obtained by the correction information acquisition unit.

4. The X-ray imaging apparatus according to claim 3, characterized in that, It also has a top plate for placing the subject of the test. The movement control unit controls the automatic movement of at least one of the X-ray irradiation unit and the top plate based on the position correction information obtained by the correction information acquisition unit, so that the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject is such that the X-ray image can be captured based on the positional relationship between the outer edges of the plurality of specified parts.

5. The X-ray imaging apparatus according to claim 3, characterized in that, It also has a top plate for placing the subject of the test. When the user moves one of the X-ray irradiation unit and the top plate, the movement control unit performs control to limit the movement of one of the X-ray irradiation unit and the top plate based on the position correction information obtained by the correction information acquisition unit.

6. The X-ray imaging apparatus according to any one of claims 2 to 5, characterized in that, It also includes a display unit that displays at least the relative movement direction of the X-ray irradiation unit, which is used to correct the position of the X-ray image reflected by the positional relationship between the outer edges of the plurality of predetermined parts in order to capture the position of the X-ray image reflected by the predetermined positional relationship, as a notification of the position correction information acquired by the correction information acquisition unit.

7. The X-ray imaging apparatus according to any one of claims 2 to 5, characterized in that, The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the multiple specified parts of the X-ray image based on the positional relationship between the outer edges of the multiple specified parts of the subject in the X-ray image, and acquire the position correction information based on the acquired relative positional offset between the outer edges of the multiple specified parts.

8. The X-ray imaging apparatus according to any one of claims 1 to 5, characterized in that, The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the plurality of specified portions based on the overlap between the outer edges of the bone or artificial joint of the subject in the X-ray image, and calculate the positional correction information for correcting the relative position of the X-ray irradiation unit relative to the bone or artificial joint of the subject to a position in which the X-ray image is captured with the outer edges of the plurality of specified portions overlapping each other.

9. The X-ray imaging apparatus according to claim 8, characterized in that, The correction information acquisition unit is configured to: when taking an image of at least one of the femur on the knee side and the scapula of the subject, calculate position correction information for correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint of the subject to a position in which the X-ray image of the outer edges of the plurality of predetermined parts overlaps with each other.

10. The X-ray imaging apparatus according to any one of claims 1 to 5, characterized in that, The correction information acquisition unit is configured to: acquire the relative positional offset between the outer edges of the plurality of specified portions based on the positional relationship between the outer edges of the bones or artificial joints of the subject in the X-ray image, and calculate the positional correction information for correcting the relative position of the X-ray irradiation unit relative to the bones or artificial joints of the subject to a position that can capture the X-ray image in which the outer edges of the plurality of specified portions are concentrically reflected.

11. The X-ray imaging apparatus according to claim 10, characterized in that, The correction information acquisition unit is configured to: when taking an image of the elbow side of the humerus of the subject, calculate position correction information for correcting the relative position of the X-ray irradiation unit with respect to the bone or artificial joint of the subject to a position that can capture the X-ray image of the outer edges of the plurality of specified portions in a concentric circle.

12. The X-ray imaging apparatus according to any one of claims 1 to 5, characterized in that, The correction information acquisition unit is configured to acquire the position correction information based on the positional relationship between the outer edges of the plurality of predetermined portions of the radiographic object of the subject in the image before position correction. The image before position correction is generated based on X-ray irradiation with a radiation dose less than that when the image after position correction is taken. The image after position correction is the X-ray image taken after the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject has been corrected.

13. The X-ray imaging apparatus according to any one of claims 1 to 5, characterized in that, The correction information acquisition unit is configured to: input a learned model obtained by machine learning from the X-ray image of the photographic object as input data into the X-ray image, thereby acquiring the outer edges of the plurality of predetermined parts based on the input X-ray image, and calculating the position correction information based on the acquired outer edges of the plurality of predetermined parts.

14. The X-ray imaging apparatus according to any one of claims 1 to 5, characterized in that, The correction information acquisition unit is configured to calculate the position correction information based on parameter information corresponding to the actual distance between the multiple specified parts of the photographic object of the subject.

15. The X-ray imaging apparatus according to claim 14, characterized in that, The correction information acquisition unit detects the size of the detection object portion of the subject in the X-ray image of the subject, and uses it as the parameter information.

16. The X-ray imaging apparatus according to claim 15, characterized in that, The correction information acquisition unit detects the size of the detection object portion of the subject from the X-ray image taken in order to acquire the position correction information, and uses this as the parameter information.

17. The X-ray imaging apparatus according to claim 15, characterized in that, The correction information acquisition unit detects the size of the target portion of the subject from an X-ray image taken from a different photographic angle than the X-ray image used to acquire the position correction information, and uses this as the parameter information.

18. The X-ray imaging apparatus according to claim 14, characterized in that, It also has a camera unit for capturing the appearance of the subject. The correction information acquisition unit is configured to calculate the position correction information based on the parameter information, which is physical information, and the physical information is information representing the size of the subject's body, calculated from the appearance image of the subject acquired by the camera unit.

19. A method for correcting photographic position, comprising the following steps: The irradiation procedure involves irradiating the subject with X-rays from the X-ray irradiation unit. The detection step involves detecting X-rays that have penetrated the subject. as well as The correction information acquisition step involves determining the outer edges of multiple defined portions of a radiographic object, which serves as a photographic object of the subject, based on the X-ray images captured in the detection step. Then, based on the determined positional relationship between the outer edges of the multiple defined portions of the radiographic object, positional correction information is acquired to correct the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject, such that the outer edges of the multiple defined portions of the radiographic object at least partially overlap each other. The radiographic object is a bone or artificial joint of the subject. The position correction information includes the relative movement direction and relative movement amount for correcting the relative position of the X-ray irradiation section with respect to the radiographic object of the subject so that the positional relationship between the outer edges of the plurality of specified portions of the radiographic object can be captured in the X-ray image reflecting the positional relationship.

20. The photographic position correction method according to claim 19, characterized in that, It also includes a position correction step, in which at least one of the following processes is performed: notifying the position correction information obtained in the correction information acquisition step, and controlling the relative position of the X-ray irradiation unit with respect to the radiographic object of the subject based on the position correction information.

21. The photographic position correction method according to claim 19 or 20, characterized in that, The correction information acquisition step includes a correction information acquisition step that calculates the position correction information based on parameter information corresponding to the actual distance between the multiple specified parts of the photographic object of the subject.

Images