X-ray diagnostic equipment

Abstract

To improve the efficiency of setting the X-ray irradiation angle and reduce the workload of an operator.SOLUTION: An X-ray diagnostic apparatus according to the embodiment includes an X-ray tube, an X-ray detector, and a tube movement control unit. The X-ray tube irradiates the part of a subject to be photographed with X rays. The X-ray detector detects X-rays. An information acquisition unit acquires an irradiation angle of the X-rays corresponding to the clinical purpose of the part to be photographed, and also acquires image data from an image sensor that photographs the part to be photographed. The tube movement control unit rotates the X-ray tube according to the irradiation angle of the X-rays, and also slides the position of the center path of the X-rays with respect to the part to be photographed on the basis of the image data.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and drawings relate to an X-ray diagnostic device. [Background technology]

[0002] X-ray diagnostic equipment irradiates the subject with X-rays and detects the transmitted X-rays with an X-ray detector to obtain an image signal of the subject. The image signal is then processed by an image processing unit to display an X-ray image on a display unit. Common X-ray diagnostic equipment systems combine an X-ray detector with a standing or lying examination table, with the X-ray tube suspended from a movable support attached to the ceiling, and the X-ray tube is moved and rotated to the appropriate imaging location relative to the standing or lying examination table using an operating unit to perform imaging.

[0003] When taking images of joints in orthopedic surgery and other fields, it is necessary to angle the X-rays relative to the human body by several degrees to several tens of degrees depending on the clinical purpose of each part. Therefore, the patient (the subject) must assume an ideal posture, and the operator must position the tube holder that holds the X-ray tube so that the ideal incident angle is achieved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-37747 Summary of the Invention [Problem to be solved by the invention]

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to improve the efficiency of setting the X-ray irradiation angle and reduce the workload of the operator. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0006] An X-ray diagnostic apparatus according to an embodiment includes an X-ray tube, an X-ray detector, and a tube movement controller. The X-ray tube irradiates the imaging region of a subject with X-rays. The X-ray detector detects the X-rays. The information acquisition unit acquires an X-ray irradiation angle corresponding to the clinical purpose of the imaging region, and acquires image data from an image sensor that images the imaging region. The tube movement controller rotates the X-ray tube according to the X-ray irradiation angle, and slides the position of the central path of the X-rays relative to the imaging region based on the image data. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing the configuration of an X-ray diagnostic apparatus according to an embodiment. [Figure 2] 1 is a diagram showing the overall configuration of an X-ray diagnostic apparatus according to an embodiment. [Figure 3] (A) is a table showing an example of an examination order, and (B) is a table showing an example of an association table. [Figure 4] 4 is a flowchart showing the operation of the X-ray diagnostic apparatus according to the embodiment. [Figure 5] 4A to 4C are explanatory diagrams showing the state of an X-ray tube in an X-ray diagnostic apparatus according to an embodiment. [Figure 6] FIG. 10 is a diagram showing the overall configuration of a first modified example of the X-ray diagnostic apparatus according to the embodiment. [Figure 7] 10(A) to 10(C) are explanatory diagrams showing the state of the X-ray tube in a first modified example of the X-ray diagnostic apparatus according to the embodiment. [Figure 8] FIG. 10 is a diagram showing the overall configuration of a second modified example of the X-ray diagnostic apparatus according to the embodiment. [Figure 9] 10(A) to 10(C) are explanatory diagrams showing the state of the X-ray tube in a second modified example of the X-ray diagnostic apparatus according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of an X-ray diagnostic apparatus will be described in detail with reference to the drawings.

[0009] Fig. 1 is a schematic diagram showing the configuration of an X-ray diagnostic apparatus according to an embodiment, and Fig. 2 is a diagram showing the overall configuration of the X-ray diagnostic apparatus according to an embodiment.

[0010] 1 and 2 show an X-ray diagnostic apparatus 1 according to an embodiment. The X-ray diagnostic apparatus 1 includes an imaging device 10 and an image processing device (e.g., a console) 30. The imaging device 10 is typically provided in an examination room, while the image processing device 30 is provided in a control room adjacent to the examination room. Also, FIGS. 1 and 2 show an image sensor C.

[0011] The imaging device 10 includes a tube holder 11, a standing examination table 12, a standing detector unit 13, a bed 14 serving as a standing examination table, a supine detector unit 15, a ceiling rail 16, a cart 17, a support 18, a high-voltage generator 19, and a holder drive unit 20.

[0012] The tube holder 11 holds an X-ray tube 11a, a variable X-ray aperture 11b, and an operation panel 11c. The X-ray tube 11a receives power from a high-voltage generator 19 and irradiates X-rays onto an area to be imaged of a subject (e.g., a patient) placed in front of the standing examination table 12 or on the bed 14. The variable X-ray aperture 11b is composed of, for example, a plurality of aperture blades. Each of the plurality of aperture blades is made of a flat lead blade or the like and blocks X-rays. The area surrounded by the plurality of aperture blades forms an aperture through which X-rays pass.

[0013] The operation panel 11c is attached to the outer wall of the tube holder 11. The operation panel 11c is a display that displays image data acquired by an image sensor C that photographs the patient. The operation panel 11c makes extensive use of graphics to display information to the operator on the display, and can employ a GUI (Graphical User Interface) that allows basic operations to be performed using an input interface.

[0014] Tube holder 11 is engaged with support column 18 so that tube holder 11 can rotate in direction Mr about an axis (e.g., the X-axis) that passes through X-ray focal point F of X-ray tube 11a and is perpendicular to the extension / contraction direction of support column 18. Under the control of processing circuit 31 of image processing device 30, tube holder 11 can be rotated in the range of -180° to +180° in rotation direction Mr about the X-axis (or Y-axis or Z-axis) that passes through X-ray focal point F by operation of holder driver 20.

[0015] The upright examination table 12 is arranged in a vertical direction at a position opposite to the tube holder 11 .

[0016] The standing detector unit 13 is supported by the standing examination table 12 and is positioned so as to be able to detect X-rays from the X-ray tube 11a. The height of the standing detector unit 13 is changed along the standing examination table 12 in accordance with changes in the height of the tube holder 11 under the control of the processing circuit 31 of the image processing device 30. Here, the height direction of the standing examination table 12 is defined as the Y-axis direction, the left-right direction of the examinee standing on the standing examination table 12 is defined as the X-axis direction, and the direction perpendicular to the X-axis and Y-axis directions is defined as the Z-axis direction.

[0017] The upright detector unit 13 includes an upright FPD 13a, a storage compartment (bucky) (not shown) for storing the upright FPD 13a, and an A / D (Analog to Digital) conversion circuit (not shown) for digitally converting the output signal of the upright FPD 13a. The upright FPD 13a includes an upright FPD main body having a plurality of detection elements arranged two-dimensionally to detect X-rays, and a grid (not shown) on the front surface of the upright FPD main body. The grid is made of grid plates made of lead or other material with high X-ray absorption and aluminum or wood or other material with high X-ray transmittance, arranged alternately, to absorb scattered rays incident on the upright FPD main body and improve the contrast of the X-ray image. The upright FPD 13a detects transmitted X-rays from a standing examinee by simple radiography and outputs the detected X-rays as image signals to the image processing device 30. Furthermore, under the control of the processing circuit 31 of the image processing device 30, the standing position detector unit 13 allows the standing position FPD 13a to slide along the Z-axis, Y-axis, and Z-axis within the standing position storage section.

[0018] The bed 14 is positioned sideways so that a patient in a supine or sitting position can be placed on it. The bed 14 has a top plate 14a on its upper part for supporting the patient, and the top plate 14a can slide along the Z-axis, Y-axis, and Z-axis under the control of the processing circuitry 31 of the image processing device 30.

[0019] The supine position detector unit 15 is supported by the bed 14. The supine position detector unit 15 includes a supine position FPD 15a, a storage unit (bucky) (not shown) for storing the supine position FPD 15a, and an A / D conversion circuit that digitally converts the output signal of the supine position FPD 15a. The supine position FPD 15a has the same structure and function as the above-mentioned upright position FPD 13a. The supine position FPD 15a detects transmitted X-rays from a patient in a supine position during X-ray imaging and outputs the detected X-rays to the image processing device 30 as an image signal.

[0020] The ceiling rail 16 is laid on the ceiling C.

[0021] The cart unit 17 supports the tube holder 11 via support columns 18. The cart unit 17 is engaged with the ceiling rail 16 so as to be movable in a direction Mz parallel to the Z-axis along the ceiling rail 16. The cart unit 17 allows the tube holder 11 to move between the side of the upright examination table 12 and the side of the bed 14 under the control of the processing circuit 31 of the image processing device 30 or manually. In other words, the cart unit 17 can change the distance (SID: Source Image Receptor Distance) between the X-ray tube 11a (X-ray focal point F) and the upright FPD 13a. The cart unit 17 may be installed so as to be movable in a direction parallel to the X-axis in addition to the direction Mz along the ceiling rail 16.

[0022] The support column 18 is supported by the cart 17, and supports the tube holder 11 at its lower end. The support column 18 is engaged with the cart 17 so as to be movable in a direction My parallel to the Y axis. The support column 18 is extendable and retractable along the direction My under the control of the processing circuit 31 of the image processing device 30. In other words, the support column 18 can change the distance (SID) between the X-ray tube 11a (X-ray focal point F) and the supine FPD 15a.

[0023] The high voltage generator 19 is capable of supplying high voltage power to the X-ray tube 11 a of the tube holder 11 under the control of the processing circuit 31 of the image processing device 30 .

[0024] The image processing device 30 is configured based on a computer and is a device that controls the operation of the entire X-ray diagnostic device 1 and performs image processing on multiple X-ray images (X-ray image data) acquired by the imaging device 10. The image processing device 30 includes a processing circuit 31, a memory 32, a display 33, an input interface 34, and a network interface 35.

[0025] The processing circuit 31 refers to a processor such as a dedicated or general-purpose central processing unit (CPU) or a microprocessor unit (MPU), as well as an application-specific integrated circuit (ASIC) and a programmable logic device. Examples of programmable logic devices include simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs). The processing circuit 31 reads and executes a program stored in the memory 32 or directly embedded in the processing circuit 31, thereby controlling the operation of the operation instruction device 6 and performing imaging according to instructions to generate X-ray images. The processing circuit 31 is an example of a processing unit.

[0026] Furthermore, the processing circuit 31 may be configured by a single processing circuit or by a combination of multiple independent processing circuit elements. In the latter case, multiple memories 32 may store programs corresponding to the functions of the multiple processing circuit elements, respectively, or one memory 32 may store programs corresponding to the functions of the multiple processing circuit elements.

[0027] The memory 32 includes semiconductor memory elements such as RAM (Random Access Memory) and flash memory, a hard disk, an optical disk, etc. The memory 32 may also include portable media such as a USB (Universal Serial Bus) memory and a DVD (Digital Video Disk). The memory 32 stores various processing programs (including application programs and an OS (Operating System)) used in the processing circuit 31, data required for executing the programs, and X-ray images. The OS may also include a GUI (Graphical User Interface) that makes extensive use of graphics to display information to the operator on the display 33 and enables basic operations to be performed via an input interface 34. The memory 32 is an example of a storage unit.

[0028] The display 33 is configured by a general display output device such as a liquid crystal display or an OLED (Organic Light Emitting Diode) display. The display 33 displays X-ray images and various information under the control of the processing circuit 31. The display 33 is an example of a display unit.

[0029] The input interface 34 includes an input device that can be operated by an operator and an input circuit that inputs signals from the input device. The input device can be realized by a trackball, a switch, a mouse, a keyboard, a touchpad that performs input operations by touching the operation surface, a touchscreen that combines a display screen and a touchpad, a non-contact input device that uses an optical sensor, a voice input device, or the like. When the operator operates the input device, the input circuit generates a signal corresponding to the operation and outputs it to the processing circuit 31. The input interface 34 is an example of an input unit.

[0030] The image sensor C is, for example, a TV camera C1. The TV camera C1 is a camera for capturing video images. The image sensor C is attached to a position where it moves and rotates in accordance with the movement and rotation of the X-ray tube 11a, for example, to the tube holder 11. The image sensor C digitally converts the acquired image data and outputs it to the image processing device 30. Note that, although the image sensor C is described as not being a component of the X-ray diagnostic device 1, it may be a component of the X-ray diagnostic device 1.

[0031] Next, the functions of the X-ray diagnostic apparatus 1 will be described.

[0032] As shown in Fig. 2, the image processing device 30 implements an information acquisition function 311, a tube movement control function 312, and an imaging control function 313 by causing the processing circuitry 31 of the image processing device 30 to execute a computer program. Note that, although the functions 311 to 313 are described as being implemented by executing a computer program, the present invention is not limited to this case. All or part of the functions 311 to 313 may be implemented in the image processing device 30 as hardware such as an ASIC.

[0033] First, the memory 32 associates at least the X-ray irradiation angle (tilt angle relative to a reference such as the vertical) with each clinical purpose of the imaging region included in the examination order (shown in FIG. 3(A)), and stores the association table. For example, the memory 32 associates the imaging region and the examinee's posture with the X-ray irradiation angle for each clinical purpose included in the examination order, as well as the imaging region and the examinee's posture, and stores the association table. An example of the association table is shown in FIG. 3(B). For example, the clinical purpose of the imaging region, "diagnosis of knee joint fracture," is associated with the imaging region, "knee joint," as well as the examinee's posture, "extended position," and the X-ray irradiation angle, "head-foot rotation angle: 10 degrees toward the foot (relative to the vertical)."

[0034] Returning to the explanation of Fig. 2, the information acquisition function 311 includes a function for acquiring an X-ray irradiation angle corresponding to the examination purpose of the imaging region, and a function for acquiring image data from the image sensor C that images the examinee. Specifically, the information acquisition function 311 acquires the examination order of the examinee. Then, the information acquisition function 311 refers to the association table stored in the memory 32 and acquires the X-ray irradiation angle corresponding to the clinical purpose of the imaging region included in the acquired examination order of the examinee.

[0035] The tube movement control function 312 includes a function to rotate the X-ray tube 11a (for example, rotate around the X-axis) according to the X-ray irradiation angle acquired by the information acquisition function 311, and to slide the position of the central path of the X-ray with respect to the imaging region (for example, slide in the Z-axis direction) based on image data acquired by the image sensor. Specifically, the tube movement control function 312 slides the X-ray tube 11a, the tabletop 14a, or the supine FPD 15a (for example, slide in the Z-axis direction) to change the relative position of the central path of the X-ray with respect to the imaging region.

[0036] The imaging control function 313 includes a function for causing the detector units 13 and 15 to perform X-ray imaging of the patient, a function for performing logarithmic conversion (LOG processing) on ​​the projection data output from the detector units 13 and 15 and adding the data as needed to generate X-ray image data, and a function for performing image processing on the generated X-ray image. Examples of image processing include enlargement / gradation / spatial filtering of the data, tracing of the minimum and maximum values ​​of data accumulated in time series, and adding processing to remove noise. The data after image processing is output to the display 33 and stored in the memory 32.

[0037] Here, X-ray imaging is broadly divided into plain radiography and fluoroscopy. Plain radiography is imaging in which X-rays are irradiated at a relatively high tube current, and primarily refers to single-shot imaging for collecting CR (Computed Radiography) images, but may also be used for video imaging. On the other hand, fluoroscopy is imaging in which X-rays are irradiated at a relatively low tube current, and primarily refers to video imaging. Fluoroscopy is also broadly divided into continuous fluoroscopy and pulse fluoroscopy. Unlike continuous fluoroscopy, pulse fluoroscopy refers to a fluoroscopy method in which X-ray pulses are intermittently and repeatedly irradiated. Compared to continuous fluoroscopy, pulse fluoroscopy provides slightly lower continuity (frame rate) of fluoroscopic images, but can reduce the radiation dose to the examinee. In this embodiment, the X-ray imaging may be either plain radiography or fluoroscopy.

[0038] The functions 311 to 313 will be described in detail later with reference to Figures 4 to 9. In Figure 4, the reference numerals with "S" followed by a number indicate the steps of the flowchart.

[0039] In step S1 of FIG. 4, the information acquisition function 311 acquires and displays information corresponding to the examinee. Specifically, the information acquisition function 311 acquires the clinical purpose of the imaging region of the examinee, "diagnosis of a knee joint fracture," from the examination order (shown in FIG. 3(A)), and acquires the X-ray irradiation angle, "10° toward the foot," corresponding to the clinical purpose of the imaging region, "diagnosis of a knee joint fracture," by referring to the association table (shown in FIG. 3(B)). Then, the information acquisition function 311 displays the X-ray irradiation angle, "10° toward the foot," on the operation panel 11c (shown in the upper part of FIG. 5(A)). Note that if the association table includes the imaging region and the examinee's posture, the information acquisition function 311 may acquire the imaging region, "knee joint," and the examinee's posture, "extended," corresponding to the clinical purpose of the imaging region, "diagnosis of a knee joint fracture," and display them on the operation panel 11c. Furthermore, the information acquisition function 311 is not limited to acquiring conditions from the examination order of the patient in question, but may allow the operator to select from among X-ray irradiation angles obtained from past examination orders of the patient.

[0040] Next, in step S2, an operator such as a technician sets up the patient. Specifically, the patient is asked to assume an imaging posture on the bed 14 in accordance with the imaging region and patient posture displayed in step S1. Then, the information acquisition function 311 displays aperture crosshairs using an aperture lamp, and the operator operates the tube holder 11 while checking the crosshairs to move the tube holder 11, i.e., the X-ray tube 11a, so that the imaging region of the patient is at the center of the irradiation field.

[0041] Next, in step S3, the information acquisition function 311 acquires image data from the TV camera C1 and performs image recognition of the intersection of the central path of the X-ray with the examinee (for example, the aperture crosshairs on the examinee) and the imaging region of the examinee based on the image data from the TV camera C1. Specifically, when the operator presses the image recognition switch W1 (shown in the upper part of FIG. 5(A)) on the operation panel 11c, the aperture lamp lights up. Then, the information acquisition function 311 performs image recognition of the imaging region of the examinee and the aperture crosshairs based on the image data from the TV camera C1.

[0042] The intersection of the central path of the X-rays with the patient is not limited to the aperture crosshairs, but may be the position pointed by the operator or a marker attached to the patient. Also, an operation to change the imaging region may be performed on the operation panel 11c. Furthermore, the information acquisition function 311 displays image data on the operation panel 11c (shown in the upper part of FIG. 5(A)).

[0043] The process of acquiring the imaging region (e.g., knee joint) based on the image data may use, for example, a lookup table (LUT) that associates the image data with the imaging region. Machine learning may also be used for this process. Deep learning using a multilayer neural network, such as a convolutional neural network (CNN) or a convolutional deep belief network (CDBN), may also be used as the machine learning.

[0044] Next, in step S4, tube movement control function 312 controls holder driver 20 to rotate tube holder 11 around an axis that passes through X-ray focal point F and is parallel to the X-axis, thereby angling tube holder 11. Specifically, when the operator presses angle setting operation start switch W2 (shown in the upper part of FIG. 5(A)) on operation panel 11c, tube movement control function 312 rotates tube holder 11 in direction Mr by a predetermined angle (e.g., 1° toward the foot from the vertical) toward the X-ray irradiation angle acquired in step S1 (changing from the state shown in FIG. 5(A) to the state shown in FIG. 5(B)). Note that operation start switch W2 is not limited to being provided on operation panel 11c and may be, for example, a foot switch. Note that FIG. 5(B) conveniently shows the final irradiation angle as "10° toward the foot from the vertical."

[0045] From the viewpoint of preventing unnecessary radiation exposure to the examinee, the tube movement control function 312 may control the aperture blades of the X-ray variable aperture 11b to narrow the opening through which the X-rays pass by controlling the X-ray variable aperture 11b in accordance with the angle of the tube holder 11. For example, the tube movement control function 312 controls the aperture blades of the X-ray variable aperture 11b to narrow the opening on the head side in order to narrow the irradiation range that has expanded toward the head side in Fig. 5(B) due to the angle.

[0046] Next, in step S5, the tube movement control function 312 slides the position of the X-ray central path P1 (the tube holder 11, the tabletop 14a, or the supine FPD 15a) relative to the imaging region in the Z-axis direction to P2 so that the imaging region recognized based on the image data in step S3 coincides with the aperture crosshairs. FIG. 5C shows an example of sliding the tube holder 11. The rotation of the tube holder 11 in the aforementioned step S4 has caused a positional deviation between the imaging region and the aperture crosshairs (shown in FIG. 5B). Therefore, in step S5, the tube movement control function 312 slides the X-ray central path to correct the positional deviation between the imaging region and the aperture crosshairs caused by the rotation of the tube holder 11.

[0047] In steps S4 and S5, the tube holder 11 is automatically rotated so that the position of the imaging region of the patient, image-recognized in step ST3, and the position of the aperture crosshairs do not change, and the central path of the X-rays is slid.

[0048] The rotation direction of the tube holder 11 in step S4 is not limited to the head-to-foot direction, i.e., the rotation direction around the X-axis, but may be the rotation direction around the Y-axis or Z-axis. Also, the sliding of the central path of the X-ray in step S5 is not limited to the Z-axis direction, but may be the X-axis direction.

[0049] Next, in step S6, tube movement control function 312 determines whether the rotation of tube holder 11 in step S4 has resulted in the X-ray irradiation angle obtained in step S1. If the answer is NO in step S6, that is, if the angle set in step S4 has not resulted in the X-ray irradiation angle obtained in step S1, the process returns to step S4, and tube movement control function 312 rotates tube holder 11 to set the angle of tube holder 11 (shown in FIG. 5(B)). In this way, fine angle setting (for example, 1° toward the head) and sliding are repeated until the X-ray irradiation angle is set to "10° toward the head."

[0050] On the other hand, if the answer is YES in step S6, that is, if the angle set in step S4 matches the X-ray irradiation angle obtained in step S1, the movement operation of tube holder 11 is terminated. Tube movement control function 312 may display information indicating "end of movement operation" on operation panel 11c of tube holder 11. Note that operation panel 11c of tube holder 11 may be provided with a switch (for example, "+1°" or "-1°") for manually fine-tuning the irradiation angle after automatic angle setting. When this switch is pressed, the process returns to the operation of step S5, and tube movement control function 312 slides the central path of the X-rays.

[0051] Next, in step S7, the imaging control function 313 causes the detector unit 15 to perform X-ray imaging of the patient and generate X-ray image data.

[0052] Although the above description has been given of the case where the imaging region is the knee joint, the present invention is not limited to this case. The imaging region may be any region where the irradiation angle is set relative to the bone. For example, the imaging region may be the elbow joint, the spine, or bones of the ear, nose, and eyes that are set relative to the skull.

[0053] As described above, the X-ray diagnostic apparatus 1 eliminates the need for the operator to manually adjust the angle, thereby improving the efficiency of setting the X-ray irradiation angle and reducing the operator's workload. It also reduces variations in irradiation angle due to differences in operator skill, and reduces unnecessary exposure due to the need to retake an image.

[0054] (First Modification) The above description deals with the case where the image sensor C is one TV camera C1 and the angle of the tube holder 11 is set on the assumption that the patient's imaging region is perpendicular to the central path of the X-rays (the X-ray irradiation angle is an inclination angle with respect to the vertical). However, the image sensor C may be two TV cameras C1, and the angle of the tube holder 11 may be set after correcting the inclination of the surface of the imaging region from the central path of the X-rays. This case will be described using Figures 6 and 7.

[0055] In FIG. 6, the same members as those in FIG. 2 are denoted by the same reference numerals and their explanations will be omitted.

[0056] The X-ray diagnostic apparatus 1 includes two TV cameras C1 arranged along the Z-axis direction. The information acquisition function 311 acquires image data from at least one of the two TV cameras C1 and performs image recognition of the imaging region and aperture crosshairs from the image data. Meanwhile, the two cameras C1 function as sensors (stereo cameras) capable of measuring distance. The information acquisition function 311 then acquires the surface of a region near the imaging region that is tilted relative to the horizontal by measuring the distance to the surface of the region. For example, when the imaging region is a knee joint, the information acquisition function 311 acquires the surface L1 of the shin near the knee joint (shown in FIG. 7(B)).

[0057] Then, the tube movement control function 312 rotates the X-ray tube so that it is perpendicular to the surface L1 acquired by the information acquisition function 311.

[0058] Next, a first modified example of the X-ray diagnostic apparatus 1 will be specifically described with reference to FIG.

[0059] When the operator presses the angle setting operation start switch W2 (shown in the upper part of Figure 7(A)) on the operation panel 11c, the tube movement control function 312 rotates the tube holder 11 in the direction Mr so that the central path of the X-ray hits the acquired shin surface L1 perpendicularly (0° to the head side (or foot side) of the perpendicular line to the surface L1) (changing from the state shown in Figure 7(A) to the state shown in Figure 7(B)).

[0060] Next, the tube movement control function 312 slides the X-ray central path P3 (the tube holder 11, the tabletop 14a, or the supine FPD 15a) in the Z-axis direction relative to the imaging region to P4 so that the imaging region recognized based on the image data coincides with the aperture crosshairs (shown in FIG. 7(C)). The rotation of the tube holder 11 causes a positional deviation between the imaging region and the aperture crosshairs (shown in FIG. 7(B)). Therefore, the tube movement control function 312 slides the X-ray central path to correct the positional deviation between the imaging region and the aperture crosshairs caused by the rotation of the tube holder 11.

[0061] If the angle of tube holder 11 is 0°, the movement of tube holder 11 ends at this point. On the other hand, if the angle of tube holder 11 is not 0°, the process proceeds to step S1 shown in Figure 4, where the desired angle is set relative to the imaging region.

[0062] Although the surface L1 is acquired by using two TV cameras C1 as a stereo camera, the present invention is not limited to this case. The surface L1 can also be acquired by measuring the distance using one TV camera C1.

[0063] As described above, according to the first modification of the X-ray diagnostic apparatus 1, it is possible to improve the efficiency of setting the X-ray irradiation angle and reduce the workload of the operator, taking into consideration the inclination of the surface of the region to be imaged. Furthermore, it is possible to reduce variations in the irradiation angle due to differences in the skill of the operator, and it is also possible to reduce unnecessary exposure to radiation due to retaking the image.

[0064] (Second Modification) The above description deals with the case where the image sensor C is a TV camera C1. However, the image sensor C may be a 3D (three-dimensional) scanner, and the angle of the tube holder 11 may be determined taking into account the inclination of the surface of the region to be imaged. This case will be described with reference to FIGS. 8 and 9.

[0065] In FIG. 8, the same members as those in FIG. 2 are denoted by the same reference numerals and their explanations will be omitted.

[0066] The X-ray diagnostic apparatus 1 includes a 3D scanner C2. The 3D scanner C2 is also called a range sensor and is a scanning type light-wave distance meter that can output physical shape data of a space. The information acquisition function 311 acquires the surface of a part near the imaging part that is tilted relative to the horizontal by measuring the distance to the surface of the part. For example, if the imaging part is a knee joint, the information acquisition function 311 acquires the surface L1 of the shin near the knee joint (shown in FIG. 9(B)).

[0067] Then, the tube movement control function 312 rotates the X-ray tube so that it is perpendicular to the surface L1 acquired by the information acquisition function 311.

[0068] Next, a second modified example of the X-ray diagnostic apparatus 1 will be specifically described with reference to FIG.

[0069] The information acquisition function 311 acquires cross-sectional image data showing a longitudinal section of the examinee based on the 3D distance image data, and sets multiple detection points in the cross-sectional image data.The information acquisition function 311 then displays the cross-sectional image data and the multiple detection points on the operation panel 11c (shown in the upper part of FIG. 9(A)).The operator designates the imaging site, which is the target incident point, from the multiple detection points displayed on the operation panel 11c.

[0070] Meanwhile, the information acquisition function 311 sets and displays a plurality of reference points from among the detection points near the imaging region (shown in the upper part of FIG. 9(B)). For example, when a predetermined number of consecutive detection points are aligned substantially in a straight line, the information acquisition function 311 sets these detection points as a plurality of reference points.

[0071] Next, the information acquisition function 311 acquires a perpendicular line L2 from a straight line (for example, the surface of the shin near the knee joint) L1 acquired from a plurality of reference points. Then, the information acquisition function 311 refers to the association table stored in the memory 32 to acquire an X-ray irradiation angle (for example, 5° toward the head) corresponding to the clinical purpose of the imaging region included in the acquired examination order of the examinee. The information acquisition function 311 sets the X-ray central path L3 at an angle obtained by adding the X-ray irradiation angle based on the association table to the perpendicular line L2 (shown in FIG. 9(B)).

[0072] Next, the information acquisition function 311 sets an irradiation point L4 at an arbitrary position on the central path L3 of the X-ray. Then, the tube movement control function 312 rotates the tube holder 11 by a predetermined angle (for example, 1° toward the head from the perpendicular line L2) toward the X-ray irradiation angle "5° toward the head from the perpendicular line L2" (changing from the state shown in FIG. 9(B) to the state shown in FIG. 9(C)). Next, the tube movement control function 312 slides the position of the central path of the X-ray (the tube holder 11, the tabletop 14a, or the supine FPD 15a) relative to the imaging region in the Z-axis and Y-axis directions so that the central path of the X-ray coincides with the irradiation point L4 on the perpendicular line L2.

[0073] When the X-ray irradiation angle is "0° toward the head (or foot)," irradiation point L4 is set on perpendicular line L2 (not shown). Therefore, tube movement control function 312 rotates tube holder 11 so that it is perpendicular to surface L1, and slides the position of the central path of the X-ray relative to the imaging region so that the central path of the X-ray coincides with irradiation point L4 on perpendicular line L2.

[0074] As described above, according to the second modification of the X-ray diagnostic apparatus 1, it is possible to improve the efficiency of setting the X-ray irradiation angle and reduce the workload of the operator, taking into consideration the inclination of the surface of the region to be imaged. Furthermore, it is possible to reduce variations in the irradiation angle due to differences in the skill of the operator, and it is also possible to reduce unnecessary exposure to radiation due to retaking the image.

[0075] The information acquisition function 311 is an example of an information acquisition unit, the tube movement control function 312 is an example of a tube movement control unit, and the imaging control function 313 is an example of an imaging control unit.

[0076] According to at least one of the embodiments described above, it is possible to improve the efficiency of setting the X-ray irradiation angle and reduce the workload of the operator.

[0077] Although several embodiments have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and spirit of the invention. [Explanation of symbols]

[0078] 1...X-ray diagnostic equipment 10...Photographing equipment 11...Tube holding part 11a...X-ray tube 11c...Operation panel 20...Holding unit drive unit 30...Image processing device 31...Processing circuit 311…Information acquisition function 312...Tube movement control function 313...Shooting control function C...Image sensor

Claims

1. an X-ray tube that irradiates an imaging region of a subject with X-rays; an X-ray detector for detecting the X-rays; an information acquisition unit that acquires the X-ray irradiation angle corresponding to the clinical purpose of the imaging region and acquires image data from an image sensor that images the imaging region; a tube movement control unit that rotates an X-ray tube according to the irradiation angle of the X-rays and slides the position of a central path of the X-rays with respect to the imaging region based on the image data; An X-ray diagnostic apparatus comprising:

2. The tube movement control unit is sliding a position of the central path of the X-rays relative to the imaging region so that the imaging region recognized based on the image data coincides with an intersection of the central path of the X-rays with the subject; 2. The X-ray diagnostic apparatus according to claim 1.

3. The tube movement control unit is sliding the position of the X-ray tube or the tabletop on which the subject is placed to slide the position of the central path of the X-rays relative to the imaging region; 3. The X-ray diagnostic apparatus according to claim 2.

4. a storage unit that stores an association table that associates the X-ray irradiation angle with each of the clinical purposes; The information acquisition unit and obtaining the X-ray irradiation angle corresponding to the clinical purpose of the imaging region by referring to the association table.

4. An X-ray diagnostic apparatus according to claim 1.

5. The storage unit storing an association table that associates the X-ray irradiation angle with the imaging region and the posture of the subject for each clinical purpose; The information acquisition unit acquiring the imaging region and the posture of the subject corresponding to the clinical purpose by referring to the association table; displaying the acquired imaging region and the posture of the subject on a display unit; 5. The X-ray diagnostic apparatus according to claim 4.

6. the image sensor is attached to a tube holder that holds the X-ray tube and acquires the image data by imaging; 4. An X-ray diagnostic apparatus according to claim 1.

7. The information acquisition unit acquiring a surface of the imaging region from a region adjacent to the imaging region that is tilted relative to the horizontal based on the image data; The tube movement control unit rotating the X-ray tube so that the X-ray tube is perpendicular to the surface of the imaging region, and sliding the central path of the X-rays so that the imaging region recognized based on the image data and an intersection of the central path of the X-rays and the subject coincide with each other; 4. An X-ray diagnostic apparatus according to claim 1.

8. The information acquisition unit acquiring a surface of the imaging region from a region adjacent to the imaging region that is tilted relative to the horizontal based on the image data; The tube movement control unit rotating the X-ray tube so that the X-ray tube is perpendicular to the surface of the imaging region, and sliding the position of the central path of the X-rays relative to the imaging region so that the central path of the X-rays coincides with an irradiation point on a line perpendicular to the surface of the imaging region; 4. An X-ray diagnostic apparatus according to claim 1.

Images