X-ray diagnostic apparatus, X-ray diagnostic method, and program

Abstract

To execute imaging of a CT image and imaging of a highly accurate X-ray projection transparent image by one X-ray CT apparatus.SOLUTION: An X-ray diagnostic apparatus according to an embodiment comprises: an imaging system; an imaging processing unit; and a super-resolution processing unit. The imaging system images a subject by irradiating the subject with the X-ray. The imaging processing unit controls the imaging system in any imaging mode in the X-ray fluoroscopic mode for obtaining the X-ray projection transparent image of the subject and the CT imaging mode for obtaining a CT (Computed Tomography) image of the subject and executes imaging of the subject. The super-resolution processing unit executes super-resolution processing according to the imaging mode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray diagnostic apparatus, an X-ray diagnostic method, and a program.

Background Art

[0002] Conventionally, techniques such as interventional treatment in which a doctor performs a procedure on a patient while imaging a subject with a medical imaging diagnostic apparatus are known. As a medical imaging diagnostic apparatus for imaging a subject during such a procedure, for example, both an X-ray CT (Computed Tomography) apparatus and an X-ray angiography apparatus may be used. As another example, an angio-CT apparatus in which an X-ray CT apparatus and an X-ray angiography apparatus are combined may also be used.

[0003] In such cases, generally, an X-ray angiography apparatus collects an X-ray fluoroscopic image of the subject, and an X-ray CT apparatus collects a cross-sectional image of the subject. However, since the X-ray angiography apparatus has a higher spatial resolution than the X-ray CT apparatus, when the X-ray CT apparatus collects an X-ray fluoroscopic image, it is required to improve the spatial resolution more than before.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems 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 perform both CT image acquisition and high-precision X-ray projection fluoroscopic image acquisition using a single X-ray CT apparatus. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. The problems corresponding to the respective effects of the respective configurations shown in the embodiments described later can also be positioned as other problems.

Means for Solving the Problems

[0006] The X-ray diagnostic apparatus according to the embodiment includes an imaging system, an imaging processing unit, and a super-resolution processing unit. The imaging system images a subject by irradiating the subject with X-rays. The imaging processing unit controls the imaging system in any one of an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT (Computed Tomography) imaging mode for obtaining a CT image of the subject, and performs imaging of the subject. The super-resolution processing unit performs super-resolution processing according to the imaging mode. When the irradiation period of X-rays by the X-ray tube starts from the middle of the first cycle of the focal position of the X-rays and ends in the middle of the second cycle, the synthesis unit generates first synthesized projection data by synthesizing one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle, generates second synthesized projection data by synthesizing one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle, and generates third synthesized projection data by synthesizing the first synthesized projection data and the second synthesized projection data. The display control unit causes the display unit to display the third synthesized projection data as an X-ray projection fluoroscopic image.

Brief Description of the Drawings

[0007]

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[0008] Hereinafter, embodiments of an X-ray diagnostic apparatus, an X-ray diagnostic method, and a program will be described in detail with reference to the drawings.

[0009] (First Embodiment) FIG. 1 is a diagram showing an example of the configuration of an X-ray computed tomography (CT) apparatus 1 (hereinafter referred to as the X-ray CT apparatus 1) according to the first embodiment. The X-ray CT apparatus 1 is an example of an X-ray diagnostic apparatus in the present embodiment.

[0010] As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a couch device 30, and a console device 40.

[0011] In the present embodiment, the rotation axis of the rotating frame 13 or the longitudinal direction of the top plate 33 of the couch device 30 in the non-tilt state is defined as the Z-axis direction, the axial direction orthogonal to the Z-axis direction and horizontal with respect to the floor surface is defined as the X-axis direction, and the axial direction orthogonal to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. In FIG. 1, for convenience of explanation, a plurality of gantry devices 10 are drawn, but in the actual configuration of the X-ray CT apparatus 1, there is only one gantry device 10.

[0012] The gantry device 10 and the couch device 30 operate based on an operation from a user via the console device 40 or an operation from a user via an operation unit provided in the gantry device 10 or the couch device 30. The gantry device 10, the couch device 30, and the console device 40 are connected to each other in a wired or wireless manner so as to be communicable.

[0013] The gantry device 10 is a device having an imaging system that collects projection data obtained by projecting a subject P with X-rays. The gantry device 10 has a substantially cylindrical opening (bore) extending in the Z-axis direction at the center. The top plate 33 of the gantry device 10 is inserted into the opening. In the present embodiment, the term "substantially cylindrical shape" includes a shape with a circular cross-section and a shape with an elliptical cross-section. More specifically, the gantry device 10 includes an X-ray tube 11 (X-ray generation unit), a wedge 16, a collimator 17, an X-ray detector 12, an X-ray high voltage device 14, a DAS (Data Acquisition System) 18, a rotating frame 13, and a control device 15. The imaging system includes at least the X-ray tube 11 and the X-ray detector 12.

[0014] The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermoelectrons from the cathode (filament) toward the anode (target) by applying a high voltage from the X-ray high-voltage device 14 and supplying a filament current. X-rays are generated when the thermoelectrons collide with the target. The X-rays generated at the tube focus in the X-ray tube 11 are shaped into a cone beam through, for example, the collimator 17 and irradiated onto the subject P. For example, the X-ray tube 11 includes a rotating anode type X-ray tube that generates X-rays by irradiating the rotating anode with thermoelectrons.

[0015] The X-ray detector 12 detects the X-rays irradiated from the X-ray tube 11 and passing through the subject P, and outputs an electrical signal corresponding to the X-ray dose to the DAS 18. Since the electrical signal detected by the X-ray detector 12 is data obtained by projecting the subject P with X-rays, it is called projection data.

[0016] The X-ray detector 12 has, for example, a plurality of detector element arrays in which a plurality of detector elements are arranged in the channel direction along an arc centered on the focus of the X-ray tube 11. Each of the plurality of detector elements detects the incident amount of X-rays. Note that the X-ray CT apparatus 1 includes various types such as a Rotate / Rotate-Type (third-generation CT) in which the X-ray tube 11 and the X-ray detector 12 rotate integrally around the subject P, and a Stationary / Rotate-Type (fourth-generation CT) in which a large number of X-ray detector elements arranged in a ring shape are fixed and only the X-ray tube 11 rotates around the subject P. Any type can be applied to the present embodiment.

[0017] The X-ray detector 12 of the present embodiment has 320 detector elements and can perform a wide range of imaging in the body axis direction of the subject P. The X-ray CT apparatus 1 including the X-ray detector 12 having such a multi-row detector element array is called an Area Detector CT (ADCT). Note that the number of rows of detector elements is an example and is not limited thereto.

[0018] In addition, the X-ray detector 12 of the present embodiment adopts an energy integrated collection method. The X-ray detector 12 is, for example, an indirect conversion type detector having a grid, a scintillator array, and a photosensor array.

[0019] The scintillator array has a plurality of scintillators, and each scintillator has a scintillator crystal that outputs light in an amount of photons corresponding to the incident X-ray dose. The grid is disposed on the X-ray incident side surface of the scintillator array and has an X-ray shielding plate that functions to absorb scattered X-rays. Note that the grid may also be referred to as a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has a function of converting the amount of light from the scintillator into an electrical signal, and has, for example, a photosensor such as a photomultiplier tube (PMT). Note that the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electrical signal.

[0020] The rotating frame 13 rotatably supports the X-ray tube 11 and the X-ray detector 12 around the rotation axis. Specifically, the rotating frame 13 is an annular frame that oppositely supports the X-ray tube 11 and the X-ray detector 12, and rotates the X-ray tube 11 and the X-ray detector 12 by a control device 15 described later. The rotating frame 13 is rotatably supported by a fixed frame formed of a metal such as aluminum. The rotating frame 13 receives power from the drive mechanism of the control device 15 and rotates around the rotation axis at a constant angular velocity.

[0021] Note that, in addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 further supports an X-ray high voltage device 14 and a DAS 18. Such a rotating frame 13 is housed in a substantially cylindrical housing in which an opening (bore) forming a photographing space is formed. The central axis of the opening coincides with the rotation axis of the rotating frame 13.

[0022] The X-ray high voltage device 14 has an electric circuit such as a transformer and a rectifier, and has a function of generating a high voltage applied to the X-ray tube 11 and a filament current supplied to the X-ray tube 11, and an X-ray control device that controls the output voltage according to the X-ray irradiated by the X-ray tube 11. The high voltage generating device may be of a transformer type or an inverter type. Note that the X-ray high voltage device 14 may be provided on the rotating frame 13 or may be provided on the fixed frame (not shown) side of the gantry device 10.

[0023] The rotating frame 13 is rotatably supported by a non-rotating part (for example, a fixed frame, not shown in FIG. 1) of the gantry device 10. The rotation mechanism includes, for example, a motor that generates a rotational driving force and a bearing that transmits the rotational driving force to the rotating frame 13 to rotate it. The motor is provided, for example, on the non-rotating part, and the bearing is physically connected to the rotating frame 13 and the motor, and the rotating frame rotates according to the rotational force of the motor.

[0024] A non-contact or contact communication circuit is provided on each of the rotating frame 13 and the non-rotating part of the gantry device 10, whereby communication is performed between the unit supported by the rotating frame 13 and the non-rotating part or an external device of the gantry device 10. For example, when optical communication is adopted as a non-contact communication method, the projection data generated by the DAS 18 is transmitted from a transmitter having a light emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on the non-rotating part of the gantry device by optical communication, and further transferred from the non-rotating part to the console device 40 by the transmitter. In addition to this, as the communication method, in addition to non-contact data transmission such as capacitive coupling type and radio wave type, a contact type data transmission method using a slip ring and an electrode brush may be adopted. Also, the rotating frame 13 is an example of a rotating part.

[0025] The control device 15 includes a processing circuit having a CPU (Central Processing Unit) or the like, and a drive mechanism such as a motor and an actuator. The processing circuit has, as hardware resources, a processor such as a CPU or an MPU (Micro Processing Unit), and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). Further, the control device 15 may be realized by a processor such as a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), or a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). When the processor is, for example, a CPU, the processor realizes its function by reading and executing a program stored in the memory. On the other hand, when the processor is an ASIC, instead of storing a program in the memory, the function is directly incorporated as a logic circuit in the circuit of the processor. Note that each processor in the present embodiment is not limited to being configured as a single circuit for each processor, and a plurality of independent circuits may be combined to be configured as one processor to realize its function. Further, a plurality of components may be integrated into one processor to realize its function.

[0026] Further, the control device 15 is attached to the console device 40 or the pedestal device 10 for input It has the function of receiving the input signal from the force interface 43 and controlling the operations of the gantry device 10 and the bed device 30. For example, the control device 15 may execute control to rotate the rotating frame 13, control to tilt the gantry device 10, and control to operate the bed device 30 and the top plate 33 under the control of the processing circuit 44 of the console device 40. Note that the control to tilt the gantry device 10 may be realized by the control device 15 rotating the rotating frame 13 about an axis parallel to the X-axis direction based on the inclination angle (tilt angle) information input by the input interface 43 attached to the gantry device 10. Also, the control device 15 may be provided on the gantry device 10 or may be provided on the console device 40.

[0027] The wedge 16 is a filter for adjusting the X-ray dose of the X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. The wedge 16 is, for example, a wedge filter or a bow-tie filter, and is a filter formed by processing aluminum to have a predetermined target angle and a predetermined thickness.

[0028] The collimator 17 is a lead plate or the like for narrowing down the X-rays transmitted through the wedge 16 to the X-ray irradiation range, and forms a slit by a combination of a plurality of lead plates or the like.

[0029] The DAS 18 collects the projection data detected by the X-ray detector 12 and transfers it to the console device 40.

[0030] The bed device 30 is a device for placing and moving a subject P to be scanned, and includes a base 31, a bed driving device 32, a top plate 33, a top plate support frame 34, and a foot pedal 35. The base 31 is a housing that supports the top plate support frame 34 so as to be movable in the vertical direction. The bed driving device 32 is a motor or actuator that moves the top plate 33 on which the subject P is placed in the major axis direction of the top plate 33. The bed driving device 32 moves the top plate 33 according to the control by the console device 40 or the control by the control device 15. The top plate 33 provided on the upper surface of the top plate support frame 34 is a plate on which the subject P is placed. Note that the bed driving device 32 may move the top plate support frame 34 in the major axis direction of the top plate 33 in addition to the top plate 33.

[0031] The foot pedal 35 is a pedal that receives an operation of a user for irradiating X-rays in X-ray imaging. For example, when the user steps on the foot pedal 35 to perform an operation of irradiating X-rays, a signal indicating the input of the operation is transmitted from the foot pedal 35 to the console device 40 or the control device 15. The foot pedal 35 is an example of an operation unit in the present embodiment. Note that the operation unit that receives the operation of the user for irradiating X-rays is not limited to the foot pedal 35, and may be a button operable by hand, a touch panel, or the like. Further, the operation unit may be provided not on the bed device 30 but on the gantry device 10 or the console device 40. Note that the bed device 30 may further include another operation unit for receiving an operation of the user for adjusting the height and inclination of the top plate 33. The other operation unit is not shown in the drawings.

[0032] The console device 40 is a device that controls the gantry device 10 and executes generation of CT image data based on a scan result by the gantry device 10. The console device 40 includes a memory 41 (storage unit), a display 42 (display unit), an input interface 43 (input unit), and a processing circuit 44 (processing unit). Data communication between the memory 41, the display 42, the input interface 43, and the processing circuit 44 is performed via a bus (BUS).

[0033] The memory 41 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit memory device that stores various information. The memory 41 stores, for example, projection data and reconstructed image data. In addition to HDDs, SSDs, etc., the memory 41 may also be a drive device that reads and writes various information to and from portable storage media such as CDs (Compact Discs), DVDs (Digital Versatile Discs), flash memories, and semiconductor memory elements such as RAMs (Random Access Memories). Also, the storage area of the memory 41 may be within the X-ray CT apparatus 1 or within an external storage device connected via a network. Further, the memory 41 stores the control program according to the present embodiment.

[0034] In addition, the memory 41 stores the projection data collected by the imaging system and the CT image data obtained by reconstructing the collected data.

[0035] The display 42 displays various information. For example, the display 42 outputs a medical image generated by the processing circuit 44, a GUI (Graphical User Interface) for receiving various operations from the operator, etc. In the present embodiment, the medical images displayed on the display 42 are cross-sectional images of the subject P based on the CT image data and X-ray projection fluoroscopic images based on the projection data.

[0036] In addition, as the display 42, for example, a liquid crystal display (LCD), a CRT (Cathode Ray Tube) display, an organic EL display (OELD: Organic Electro Luminescence Display), a plasma display, or any other display can be used as appropriate. Also, the display 42 may be provided on the gantry device 10. Further, the display 42 may be a desktop type or may be configured as a tablet terminal capable of wireless communication with the console device 40 main body.

[0037] The input interface 43 receives various input operations from the user, converts the received input operations into electrical signals, and outputs them to the processing circuit 44. For example, the input interface 43 receives from the operator collection conditions when collecting projection data, reconstruction conditions when reconstructing CT image data, and the like. As the input interface 43, for example, a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch pad, and a touch panel display can be appropriately used.

[0038] Note that in the present embodiment, the input interface 43 is not limited to those provided with physical operation components such as a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch pad, and a touch panel display. For example, a processing circuit for electrical signals that receives an electrical signal corresponding to an input operation from an external input device provided separately from the apparatus and outputs this electrical signal to the processing circuit 44 is also included in the examples of the input interface 43. Further, the input interface 43 is an example of an operation unit or an input unit.

[0039] Also, the input interface 43 may be provided in the gantry device 10. For example, the above-described foot pedal 35 may be the input interface 43. Also, the input interface 43 may be configured by a tablet terminal or the like that can communicate wirelessly with the console device 40 main body.

[0040] The processing circuit 44 controls the operation of the entire X-ray CT apparatus 1 according to the electrical signal of the input operation output from the input interface 43. For example, the processing circuit 44 includes a reception function 441, a photographing processing function 442, an acquisition function 443, a super-resolution processing function 444, a pre-processing function 445, a reconstruction processing function 446, and a display control function 447. Here, for example, as shown in FIG. 1 The respective processing functions executed by the reception function 441, the imaging processing function 442, the acquisition function 443, the super-resolution processing function 444, the preprocessing function 445, the reconstruction processing function 446, and the display control function 447, which are components of the processing circuit 44, are recorded in the memory 41 in the form of programs executable by a computer. The processing circuit 44 is, for example, a processor, and reads out each program from the memory 41 and executes it to realize the functions corresponding to the read-out programs. In other words, the processing circuit 44 in the state of having read out each program will have each function shown in the processing circuit 44 of FIG. 1. The reception function 441 is an example of a reception unit. The imaging processing function 442 is an example of an imaging processing unit. The acquisition function 443 is an example of an acquisition unit. The super-resolution processing function 444 is an example of a super-resolution processing unit. The preprocessing function 445 is an example of a preprocessing unit. The reconstruction processing function 446 is an example of a reconstruction processing unit. The display control function 447 is an example of a display control unit and an output unit.

[0041] In FIG. 1, the case where the reception function 441, the imaging processing function 442, the acquisition function 443, the super-resolution processing function 444, the preprocessing function 445, the reconstruction processing function 446, and the display control function 447 are realized by a single processing circuit 44 is shown, but the embodiment is not limited to this. For example, the processing circuit 44 may be configured by combining a plurality of independent processors, and each processor may execute each program to realize each processing function. Also, each processing function of the processing circuit 44 may be appropriately distributed or integrated into a single or a plurality of processing circuits and realized.

[0042] The reception function 441 receives various operations by the user via the input interface 43, the foot pedal 35, and other operation units. For example, the reception function 441 receives the operation of the user pressing an operation button displayed on the display 42. Also, the reception function 441 receives the operation of the user selecting a later-described imaging mode and the operation instructing the execution of super-resolution processing. Also, the reception function 441 receives the operation of the user starting and ending imaging via the foot pedal 35 or the like.

[0043] The imaging processing function 442 controls the imaging system to perform imaging of the subject P. Specifically, the imaging processing function 442 controls the operations of the X-ray high voltage device 14, the X-ray detector 12, the control device 15, the DAS 18, and the bed driving device 32, thereby controlling the collection process of the X-rays that have passed through the subject P in the gantry device 10.

[0044] The imaging processing function 442 of the present embodiment can perform imaging of the subject P in at least two different imaging modes. More specifically, the imaging processing function 442 controls the imaging system in either an X-ray fluoroscopy imaging mode or a CT imaging mode according to the user's selection, and performs imaging of the subject P.

[0045] The X-ray fluoroscopy imaging mode is a mode for obtaining an X-ray projection fluoroscopic image of the subject P. The X-ray fluoroscopic image data is projection data in which the X-rays irradiated by the X-ray tube 11 from a specified position are collected by the X-ray detector 12. The X-ray projection fluoroscopic image is a fluoroscopic image based on the projection data collected in the X-ray fluoroscopy imaging mode. In the present embodiment, the un-reconstructed projection data is used as two-dimensional X-ray projection fluoroscopic image data. Note that the X-ray fluoroscopy imaging mode is an example of the second imaging mode. Note that the X-ray projection fluoroscopic image may be simply referred to as a projection fluoroscopic image.

[0046] In the X-ray fluoroscopy imaging mode, the specified position at which the X-ray tube 11 irradiates the subject P with X-rays may be, for example, the position directly above the subject P as shown in FIG. 1. The position of the X-ray tube 11 is also referred to as the view position and is represented by an angle of 0° to 360°. For example, when the X-ray tube 11 is located directly above the subject P, the view position of the X-ray tube 11 is 90°. Note that the specified position is not limited to this example and may be set by the user as well.

[0047] In the fluoroscopic imaging mode, during imaging, the rotating frame 13 of the X-ray CT apparatus 1 may not rotate, and the X-ray tube 11 may be fixed at the specified position. Also, during imaging, the rotating frame 13 may rotate, and X-rays may be irradiated at the timing when the X-ray tube 11 reaches the specified position. Further, in the fluoroscopic imaging mode, the top plate 33 does not move during X-ray irradiation from the X-ray tube 11.

[0048] FIG. 2 is an example of the projection data 91 in the first embodiment. In the present embodiment, the projection data 91 displayed on the display 42 described later is referred to as an X-ray projection fluoroscopic image.

[0049] The X-ray fluoroscopic image is used, for example, in interventional treatment to visually recognize the position of a device inserted into the body of the subject P on whom the doctor is performing a procedure. For example, in the example shown in FIG. 2, a catheter 80 inserted into the heart of the subject P is depicted on the projection data 91 together with the bones and organs of the subject P. In the present embodiment, the X-ray fluoroscopic image is a two-dimensional still image.

[0050] The CT imaging mode is a mode for obtaining a CT image of the subject P. That is, in the CT imaging mode, the imaging processing function 442 executes imaging for generating general CT image data. Therefore, in the CT imaging mode, depending on the imaging method, the top plate 33 can also be moved during X-ray irradiation from the X-ray tube 11. The CT image data is data obtained by reconstructing the projection data by the reconstruction processing function 446 described later. Also, the CT image is, for example, a two-dimensional cross-sectional image or a three-dimensional image based on the CT image data displayed on the display 42 by the display control function 447 described later.

[0051] For example, in the CT imaging mode, the imaging processing function 442 causes the imaging system to execute a process of imaging the subject P with the rotating frame 13 rotating. Note that the CT imaging mode is an example of the first imaging mode.

[0052] FIG. 3 shows an example of the CT image data 92 in the first embodiment. The CT image data 92 is, for example, three-dimensional volume data as shown in FIG. 3. The display control function 447 described later causes the display 42 to display a CT image that is an arbitrary cross-sectional image or three-dimensional image from the CT image data 92 according to a user's designation or the like.

[0053] The imaging processing function 442 controls the imaging system to image the subject P in either the fluoroscopic X-ray imaging mode or the CT imaging mode according to the selection by the user received by the reception function 441.

[0054] Note that when the imaging processing function 442 performs imaging in the CT imaging mode, it may further perform imaging of a scan image (positioning image).

[0055] The positioning image is an image for setting the imaging range of the diagnostic CT image. Also, the imaging for obtaining the positioning image is called positioning imaging. Generally, the positioning image is a two-dimensional image. When distinguishing between a normal CT image and a positioning image, the normal CT image may sometimes be called a "diagnostic CT image".

[0056] In positioning imaging, the imaging processing function 442 performs imaging using an imaging method different from the fluoroscopic X-ray imaging mode. More specifically, as described above, in the fluoroscopic X-ray imaging mode, the top plate 33 does not move during X-ray irradiation from the X-ray tube 11, but in the positioning imaging in the CT imaging mode, the top plate 33 moves during X-ray irradiation.

[0057] For example, during the execution of positioning imaging, the imaging processing function 442 moves the top plate 33 of the bed device 30 while keeping the rotating frame 13 (gantry rotating part) of the gantry device 10 in a non-rotating state. Further, during positioning imaging, the imaging processing function 442 performs data collection using only the vicinity of the center in the Z-axis direction of the X-ray detector 12. Specifically, the imaging processing function 442 controls the collimator 17 directly below the X-ray tube 11 so that X-rays are irradiated only in the vicinity of the center in the Z-axis direction of the X-ray detector 12, and performs imaging with the X-ray irradiation range narrowed.

[0058] Also, as another positioning imaging method, there is a method of capturing a three-dimensional positioning image. Such a method is also called a 3D scanner, and it performs a CT scan with a lower dose than CT imaging for capturing diagnostic CT images. When the imaging processing function 442 executes three-dimensional positioning imaging, an imaging method similar to that for capturing CT images in the CT imaging mode is used for everything other than the X-ray dose. The imaging processing function 442 may obtain a three-dimensional positioning image of the subject P by such three-dimensional positioning imaging.

[0059] Note that the imaging processing function 442 may execute only the capture of diagnostic CT images without executing positioning imaging.

[0060] Returning to FIG. 1, the acquisition function 443 acquires the projection data collected by the imaging system. More specifically, the acquisition function 443 acquires the projection data transferred from the DAS 18 and stores it in the memory 41.

[0061] The super-resolution processing function 444 performs super-resolution processing on the projection data 91 or the CT image data 92 according to the imaging mode. More specifically, the super-resolution processing function 444 switches the data to be super-resolved according to whether the imaging processing function 442 has imaged the subject P in either the fluoroscopic imaging mode or the CT imaging mode. Note that the super-resolution processing for the projection data 91 is also referred to as super-resolution processing in the projection data domain, and the super-resolution processing for the CT image data 92 is also referred to as super-resolution processing in the CT image domain.

[0062] For example, when the imaging processing function 442 executes imaging of the subject P in the fluoroscopic imaging mode, the super-resolution processing function 444 performs super-resolution processing on the projection data 91. In the present embodiment, the super-resolution processing function 444 targets the projection data 91 that has been pre-processed by the pre-processing function 445 described later for super-resolution processing.

[0063] In this embodiment, both the data detected by the X-ray detector 12 before preprocessing and the data preprocessed by the preprocessing function 445 described later are referred to as projection data 91. However, the data before preprocessing may be distinguished as detection data.

[0064] In addition, when the imaging processing function 442 executes imaging of the subject P in the CT imaging mode, the super-resolution processing function 444 executes super-resolution processing on the CT image data 92.

[0065] The method of super-resolution processing is not particularly limited, and a known method can be adopted. For example, the super-resolution processing function 444 may execute super-resolution processing on the projection data 91 or the CT image data 92 using a learned model obtained by learning low-resolution data / images and high-resolution data / images by machine learning.

[0066] For example, when performing super-resolution processing on the projection data 91, a plurality of learning pairs are prepared with the low-resolution projection data as input information and the high-resolution projection data as target (teacher) information. Then, a machine learning model such as a CNN (Convolutional Neural Network) is trained to obtain a learned model for the projection data 91. The low-resolution projection data may be obtained by imaging the subject P or a phantom, or may be obtained by applying a resolution reduction process to the high-resolution data obtained by imaging the subject P or a phantom. The high-resolution projection data may also be obtained by imaging the subject P or a phantom, or may be obtained by applying a resolution improvement process to the low-resolution projection data obtained by imaging the subject P or a phantom. The high-quality projection data may be, for example, high-quality projection data obtained using the focus control method described later, or X-ray projection data imaged using a high-definition X-ray detector with a small pixel pitch.

[0067] ​Generally, since the pixel pitch of a flat-panel X-ray detector used in a C-arm type X-ray imaging device or the like is smaller than the pixel pitch of a curved X-ray detector used in CT, after applying a process of converting an image of the flat-panel X-ray detector into an image taken by the curved X-ray detector of CT, it can also be used as target information. In this case, according to one of the embodiments, a super-resolution model is obtained by training a machine learning model with high-quality projection data taken with focus control as target information and relatively low-quality projection data taken without focus control as input information, and the super-resolution model is applied to the relatively low-quality projection data taken without focus control.

[0068] Alternatively, high-quality processing by focus control may be applied to projection data with high resolution and low resolution respectively. In that case, for example, as the projection data that becomes high-resolution target information, the projection data taken using a high-definition X-ray detector as described above can be used.

[0069] Also, instead of learning using only X-ray projection data, a transfer learning method may be used. Based on a super-resolution model learned using an optical image, an MRI image, or the like that is not X-ray projection data, the X-ray projection data may be further learned using the above method to obtain a trained super-resolution model. Furthermore, for example, by using an autoencoder network in which an encoder network and a decoder network are connected in series as a model, a trained super-resolution model may be obtained using a learning algorithm that does not use teacher information.

[0070] Similarly, when performing super-resolution processing on the CT image data 92, low-resolution CT image data as input information and high-resolution CT image data as target information are used as a learning pair, and a plurality of such learning pairs are prepared. By training a machine learning model such as a CNN (Convolutional Neural Network), a trained model for projection data is obtained. The low-resolution CT image data may be obtained by reconstructing the projection data obtained by photographing the subject P or the phantom, or may be obtained by applying a resolution reduction process to the high-resolution CT image data obtained by photographing the subject P or the phantom, or may be CT image data reconstructed after applying a resolution reduction process to the high-resolution projection data. Also, a resolution reduction process may be incorporated in the process of reconstructing the CT image from the high-resolution projection data.

[0071] The high-resolution CT image data may also be obtained by reconstructing the projection data obtained by photographing the subject P or the phantom, or may be obtained by applying a resolution improvement process to the low-resolution CT image data obtained by photographing the subject P or the phantom, or may be CT image data reconstructed after applying a resolution improvement process to the low-resolution projection data. Also, a resolution improvement process may be incorporated in the process of reconstructing the CT image from the high-resolution projection data.

[0072] When reconstructing these CT image data, the projection data used may be obtained by the method described in the explanation of the training method of the super-resolution model of the above-described projection database.

[0073] Alternatively, instead of using only X-ray projection data for learning, a transfer learning method may be used. Based on a super-resolution model learned using optical images, MRI images, etc., which are not CT image data, the CT image data may be further used to learn the model as described above to obtain a trained super-resolution model. Furthermore, for example, by using an autoencoder network in which an encoder network and a decoder network are connected in series as a model, a trained super-resolution model may be obtained using a learning algorithm that does not use teacher information.

[0074] The trained model may be stored in, for example, the memory 41, or may be incorporated into the super-resolution processing function 444 in the form of hardware implementation using, for example, an FPGA. Specifically, both the trained super-resolution model used in the fluoroscopic X-ray imaging mode and the trained super-resolution model used in the CT imaging mode are stored in the memory 41 or incorporated into the super-resolution processing function 444. Also, the super-resolution processing function 444 may change the content of the super-resolution processing applied in the fluoroscopic X-ray imaging mode and the CT imaging mode.

[0075] Also, the super-resolution processing function 444 is configured to execute super-resolution processing when an operation is performed by the user to instruct the execution of super-resolution processing.

[0076] The super-resolution processing function 444 stores the projection data 91 or CT image data 92 that has undergone super-resolution processing in the memory 41.

[0077] The preprocessing function 445 performs preprocessing on the collected projection data 91, such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, and beam hardening correction. Note that the content of the preprocessing may be different when imaging is performed in the fluoroscopic X-ray imaging mode and when imaging is performed in the CT imaging mode. Alternatively, the preprocessing function 445 may not perform preprocessing on the projection data 91 when imaging is performed in the fluoroscopic X-ray imaging mode.

[0078] The reconstruction processing function 446 generates CT image data 92 by reconstructing the projection data 91. Note that the reconstruction processing function 446 of this embodiment reconstructs the projection data 91 that has been preprocessed by the preprocessing function 445. As the reconstruction processing, the reconstruction processing function 446 uses, for example, the filtered back projection method (FBP method) or the successive approximation reconstruction method.

[0079] In addition, when imaging in the X-ray fluoroscopy mode is executed, the X-ray CT apparatus 1 of this embodiment outputs, for at least one of display and analysis, an X-ray projection fluoroscopic image based on the projection data collected in the X-ray fluoroscopy mode. When imaging in the CT imaging mode is executed, the X-ray CT apparatus 1 outputs, for at least one of display and analysis, a CT image reconstructed based on the projection data collected in the CT imaging mode.

[0080] More specifically, the display control function 447 causes the display 42 to display a medical image based on the projection data 91 or the CT image data 92 that has been subjected to super-resolution processing by the super-resolution processing function 444.

[0081] For example, when the subject P is imaged in the X-ray fluoroscopy mode, the display control function 447 causes the display 42 to display the projection data 91 that has been subjected to super-resolution processing as an X-ray projection fluoroscopic image. When the subject P is imaged in the CT imaging mode, the display control function 447 causes the display 42 to display a CT image based on the CT image data 92 that has been subjected to super-resolution processing.

[0082] In addition, the display control function 447 causes the display 42 to display a GUI that can be operated by the user.

[0083] For example, the display control function 447 causes the display 42 to display a shooting mode selection screen on which the user can select whether to shoot the subject P in either the X-ray fluoroscopy mode or the CT imaging mode.

[0084] FIG. 4 is a diagram showing an example of a shooting mode selection screen 421 according to the first embodiment. As shown in FIG. 4, the shooting mode selection screen 421 includes an X-ray fluoroscopy shooting mode selection button 71 and a CT shooting mode selection button 72.

[0085] The X-ray fluoroscopy shooting mode selection button 71 is an image button that accepts a selection operation of the X-ray fluoroscopy shooting mode by the user. Also, the CT shooting mode selection button 72 is an image button that accepts a selection operation of the CT shooting mode by the user. Note that the display control function 447 may distinguish and display which of the X-ray fluoroscopy shooting mode and the CT shooting mode is selected in a display mode such as the color of the X-ray fluoroscopy shooting mode selection button 71 and the CT shooting mode selection button 72. In the example shown in FIG. 4, it is assumed that the X-ray fluoroscopy shooting mode selection button 71 has been pressed by the user.

[0086] Also, the display control function 447 may display a message M1 of an operation explanation such as "Please select a shooting mode" on the shooting mode selection screen 421. Note that the configuration of the shooting mode selection screen 421 shown in FIG. 4 is an example and is not limited thereto. Also, the shooting mode selection screen 421 may be shared with other input operation screens.

[0087] Also, the display control function 447 causes the display 42 to display a super-resolution processing operation screen on which the user can select whether to execute super-resolution processing in each of the X-ray fluoroscopy shooting mode and the CT shooting mode.

[0088] FIG. 5 is a diagram showing an example of a super-resolution processing operation screen 422 according to the first embodiment. As shown in FIG. 5, the super-resolution processing operation screen 422 includes, for example, an image display area A1 and a super-resolution processing execution button 73.

[0089] The super-resolution processing execution button 73 is an image button that can accept an operation for the user to select whether to execute super-resolution processing. For example, when the user presses the super-resolution processing execution button 73, the function of the super-resolution processing by the super-resolution processing function 444 is turned on. Also, when the user does not press the super-resolution processing execution button 73, the function of the super-resolution processing by the super-resolution processing function 444 is turned off. Note that buttons for turning on and off the super-resolution processing function may be provided separately. Further, the display control function 447 displays whether the super-resolution processing function is on or off in a display mode such as the color of the super-resolution processing execution button 73. Note that the display control function 447 may display "on" or "off" on or near the super-resolution processing execution button 73.

[0090] In the present embodiment, in both the fluoroscopic X-ray imaging mode and the CT imaging mode, the display mode of the super-resolution processing execution button 73 is common. That is, the super-resolution processing execution button 73 is displayed in the same mode regardless of whether the fluoroscopic X-ray imaging mode or the CT imaging mode is selected.

[0091] Therefore, depending on which of the fluoroscopic X-ray imaging mode and the CT imaging mode is selected by the user, the data of the target of the super-resolution processing indicated by the super-resolution processing execution button 73 is different. For example, if the fluoroscopic X-ray imaging mode is selected by the user, when the user presses the super-resolution processing execution button 73, the operation becomes an operation to turn on the super-resolution processing for the projection data 91. Also, if the CT imaging mode is selected by the user, when the user presses the super-resolution processing execution button 73, the operation becomes an operation to turn on the super-resolution processing for the CT image data 92. When the CT imaging mode is selected by the user, if the user presses the super-resolution processing execution button 73, the operation becomes an operation to turn on the super-resolution processing for the CT image data 92.

[0092] For example, when the X-ray fluoroscopy imaging mode is selected and the user has not pressed the super-resolution processing execution button 73, the display control function 447 causes the projection data 91 before super-resolution processing to be displayed in the image display area A1. Further, when the X-ray fluoroscopy imaging mode is selected and the user presses the super-resolution processing execution button 73, the display control function 447 causes the projection data 91 after super-resolution processing to be displayed in the image display area A1.

[0093] Also, when the CT imaging mode is selected and the user has not pressed the super-resolution processing execution button 73, the display control function 447 causes a CT image based on the CT image data 92 before super-resolution processing to be displayed in the image display area A1. Further, when the CT imaging mode is selected and the user presses the super-resolution processing execution button 73, the display control function 447 causes a CT image based on the CT image data 92 after super-resolution processing to be displayed in the image display area A1.

[0094] Note that the on / off of the super-resolution processing may be selected by the user in advance before imaging. For example, it may be possible to select the imaging mode and the on / off of the super-resolution processing on one operation screen.

[0095] FIG. 6 is a diagram showing an example of an operation screen of another aspect according to the first embodiment. On the operation screen 423 shown in FIG. 6, an X-ray fluoroscopy imaging mode selection button 71, a CT imaging mode selection button 72, and a super-resolution processing execution button 73 are displayed on one screen. The display timing of the operation screen 423 is, for example, before the start of imaging. When the super-resolution processing execution button 73 is displayed at the same timing as the X-ray fluoroscopy imaging mode selection button 71 and the CT imaging mode selection button 72 as in the operation screen 423, the user also selects the on / off of the super-resolution processing when selecting the imaging mode before the start of imaging.

[0096] Next, the flow of the imaging process executed by the X-ray CT apparatus 1 of the present embodiment configured as described above will be described.

[0097] FIG. 7 is a flowchart showing an example of the flow of imaging processing executed by the X-ray CT apparatus 1 according to the first embodiment.

[0098] First, the display control function 447 causes the imaging mode selection screen 421 to be displayed on the display 42 (S101).

[0099] Next, the reception function 441 receives an operation of the user for selecting whether to image the subject P in either the fluoroscopic imaging mode or the CT imaging mode (S102).

[0100] For example, when the fluoroscopic imaging mode selection button 71 on the imaging mode selection screen 421 is pressed by the user, the reception function 441 receives that the fluoroscopic imaging mode has been selected by the user (S102 “fluoroscopic imaging mode”).

[0101] Then, the reception function 441 determines whether or not it has received an operation of the user to start imaging via the foot pedal 35 or the touch panel or the like (S103). Note that a start imaging button capable of receiving an instruction from the user to start imaging may be displayed on the imaging mode selection screen 421 by the display control function 447.

[0102] When the reception function 441 has not received an operation of the user to start imaging (S103 “No”), it waits for the user's operation.

[0103] When the reception function 441 has received an operation of the user to start imaging (S103 “Yes”), the imaging processing function 442 executes imaging in the fluoroscopic imaging mode (S104). For example, under the control of the imaging processing function 442, the control device 15 controls the operations of the gantry device 10 and the bed device 30, and the X-ray tube 11 irradiates the subject P with X-rays from a specified position. Further, the X-ray detector 12 detects the X-rays irradiated from the X-ray tube 11 and passing through the subject P, and outputs an electrical signal corresponding to the X-ray dose to the DAS 18 as projection data. The DAS 18 transmits the projection data 91 to the console device 40. The acquisition function 443 acquires the projection data 91 transmitted from the DAS 18.

[0104] Next, the preprocessing function 445 performs preprocessing on the projection data 91 acquired by the acquisition function 443 (S106).

[0105] Then, the display control function 447 causes the super-resolution processing operation screen 422 to be displayed on the display 42 (S107).

[0106] Then, the reception function 441 determines whether or not it has received an operation to turn on the super-resolution processing function by the user (S108). Note that the reception of the on / off operation of the super-resolution processing function by the user is not limited to the timing of S108, and as described in FIG. 6, it may be before the execution of the imaging process.

[0107] When the reception function 441 has received an operation to turn on the super-resolution processing function by the user (S108 “Yes”), the super-resolution processing function 444 executes super-resolution processing on the preprocessed projection data 91 (S109).

[0108] Then, the display control function 447 causes the projection data 91 after super-resolution processing to be displayed on the display 42 (S110).

[0109] Also, when the reception function 441 has not received an operation to turn on the super-resolution processing function by the user (S108 “No”), or when the reception function 441 has received an operation to turn off the super-resolution processing function by the user, the display control function 447 causes the preprocessed projection data 91 that has not been super-resolution processed to be displayed on the display 42 as an X-ray projection fluoroscopic image (S111).

[0110] Then, when the reception function 441 has not received an operation to end the imaging (S112 “No”), the process returns to the process of selecting the processing mode of S101, and the process is repeated. Alternatively, it may return to the process of waiting for the imaging start operation of S103 while remaining in the X-ray fluoroscopic imaging mode.

[0111] Also, when the CT imaging mode selection button 72 is pressed by the user on the imaging mode selection screen 421, the reception function 441 accepts that the CT imaging mode has been selected by the user (S102 “CT imaging mode”).

[0112] Then, the reception function 441 determines whether it has received an operation to start imaging by the user via the foot pedal 35 or the touch panel or the like (S113).

[0113] If the reception function 441 has not received an operation to start imaging by the user (S113 “No”), it waits for the user's operation.

[0114] When the reception function 441 receives an operation to start imaging by the user (S113 “Yes”), the imaging processing function 442 performs imaging in the CT imaging mode (S114). In this flowchart, the imaging processing function 442 does not perform positioning imaging and only performs imaging of CT images for diagnosis. However, positioning imaging may be performed before imaging of CT images for diagnosis.

[0115] Next, the preprocessing function 445 performs preprocessing on the projection data 91 collected by imaging in the CT imaging mode (S115).

[0116] The reconstruction processing function 446 generates CT image data 92 by reconstructing the preprocessed projection data 91 (S116).

[0117] Then, the display control function 447 causes the super-resolution processing operation screen 422 to be displayed on the display 42 (S117).

[0118] Then, the reception function 441 determines whether it has received an operation to turn on the super-resolution processing function by the user (S118).

[0119] When the reception function 441 receives an operation by the user to turn on the super-resolution processing function (S118 “Yes”), the super-resolution processing function 444 executes super-resolution processing on the CT image data 92 (S119).

[0120] Then, the display control function 447 causes the display 42 to display a CT image based on the CT image data 92 after super-resolution processing (S120).

[0121] Also, when the reception function 441 has not received an operation by the user to turn on the super-resolution processing function (S118 “No”), or when the reception function 441 has received an operation by the user to turn off the super-resolution processing function, the display control function 447 causes the display 42 to display a CT image based on the CT image data 92 that has not been super-resolved (S121).

[0122] Then, the process proceeds to the process of S112. If the imaging has not ended, the process returns to the process of S101. Also, when the reception function 441 has received an operation to end the imaging (S112 “Yes”), the processing of this flowchart ends (S112).

[0123] As described above, in the X-ray CT apparatus 1 of the present embodiment, the subject P can be imaged in two imaging modes, namely, the X-ray fluoroscopic imaging mode and the CT imaging mode, and the data to be super-resolved is switched according to whether the subject P is imaged in the X-ray fluoroscopic imaging mode or the CT imaging mode. Therefore, according to the present embodiment, both the imaging of CT images and the imaging of high-precision X-ray projection fluoroscopic images can be performed with one X-ray CT apparatus 1.

[0124] As a conventional imaging method used in interventional treatments such as angiographic procedures where a doctor performs a procedure on a patient while imaging the subject, there is a method of imaging the subject using two devices, an X-ray CT device and an X-ray angiography device. In such a method, since both an X-ray CT device and an X-ray angiography device are required, it is necessary to secure a large examination room. Also, since the subject needs to be moved between the two modalities, it may take time to switch between imaging the X-ray projection fluoroscopic image and the CT image.

[0125] Also, as another comparative example, there is an angio-CT device in which an X-ray CT device and an X-ray angiography device are combined. The angio-CT device includes a C-arm similar to that of an X-ray angiography device in addition to a gantry device similar to a normal CT device. In such an angio-CT device, it is possible to obtain both an X-ray projection fluoroscopic image and a CT image with a single device. However, since it includes both a gantry device and a C-arm, it is larger than a normal X-ray CT device. Also, since the gantry device is used for CT image acquisition and the C-arm is used for X-ray projection fluoroscopic image acquisition, movement of the subject occurs during the imaging mode switch.

[0126] On the other hand, in the X-ray CT device 1 of the present embodiment, since two types of imaging, an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image and a CT imaging mode for obtaining a CT image, are possible with one imaging system, it is possible to save space in the X-ray CT device 1 and shorten the time required for switching imaging.

[0127] Also, generally, an X-ray flat panel detector used in an X-ray angiography device (Flat Panel The detector (FPD) has higher spatial resolution than the X-ray detector used in an X-ray CT apparatus. As an example, in the X-ray planar detector of an X-ray angiography apparatus, the spatial resolution is generally 0.1 mm or less, whereas the spatial resolution of the ADCT is about 0.3 mm. For this reason, when the projection data of a normal X-ray CT apparatus is displayed as an X-ray projection fluoroscopic image, the spatial resolution may be insufficient. In addition, it may be difficult to increase the number of detection elements of the X-ray detector of the X-ray CT apparatus to the same level as that of the X-ray angiography apparatus for reasons such as cost.

[0128] On the other hand, the X-ray CT apparatus 1 of the present embodiment has a super-resolution processing function and switches the data to be subjected to the super-resolution processing according to whether the subject P is imaged in either the X-ray fluoroscopic imaging mode or the CT imaging mode. Therefore, in the case of the X-ray fluoroscopic imaging mode, an X-ray projection fluoroscopic image with high spatial resolution can be generated.

[0129] More specifically, when the X-ray CT apparatus 1 of the present embodiment executes imaging of the subject P in the X-ray fluoroscopic imaging mode, super-resolution processing is executed on the projection data 91, and the projection data 91 subjected to the super-resolution processing is displayed on the display 42 as an X-ray projection fluoroscopic image. For this reason, the X-ray CT apparatus 1 of the present embodiment can present an X-ray projection fluoroscopic image having high spatial resolution by super-resolution processing during an intervention treatment or the like in which a doctor performs a procedure on the subject P.

[0130] In addition, when the X-ray CT apparatus 1 of the present embodiment executes imaging of the subject P in the CT imaging mode, the projection data 91 is reconstructed to generate CT image data 92, and super-resolution processing is executed on the CT image data 92. For this reason, the X-ray CT apparatus 1 of the present embodiment can improve the spatial resolution not only for the X-ray projection fluoroscopic image but also for a normal CT image.

[0131] In addition, the X-ray CT apparatus 1 according to the present embodiment controls the imaging system to image the subject P in either an X-ray fluoroscopic imaging mode or a CT imaging mode according to the selection by the user. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, the subject P can be imaged in the imaging mode desired by the user.

[0132] Further, the X-ray CT apparatus 1 of the present embodiment causes the display 42 to display an X-ray fluoroscopic imaging mode selection button 71 that can receive an operation for selecting the X-ray fluoroscopic imaging mode by the user, and a CT imaging mode selection button 72 that can receive an operation for selecting the CT imaging mode by the user. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, the user can easily select the imaging mode.

[0133] In addition, the X-ray CT apparatus 1 of the present embodiment executes super-resolution processing when the execution of super-resolution processing is selected by the user. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, when the user desires, X-ray projection fluoroscopic image data or CT image data with improved spatial resolution can be generated.

[0134] Further, the X-ray CT apparatus 1 of the present embodiment displays the super-resolution processing execution button 73 in the same manner regardless of whether the X-ray fluoroscopic imaging mode or the CT imaging mode is selected by the user. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, the user can perform the execution operation of the super-resolution processing without being aware that the data target of the super-resolution processing is different depending on the imaging mode.

[0135] (Second Embodiment) In the above-described first embodiment, the spatial resolution of the X-ray projection fluoroscopic image was improved by super-resolution processing. In contrast, in this second embodiment, the spatial resolution of the X-ray projection fluoroscopic image is improved by FFS (flying focal spot).

[0136] FIG. 8 is a diagram showing an example of the configuration of the X-ray CT apparatus 1 according to the second embodiment. The X-ray CT apparatus 1 of the present embodiment includes a gantry device 10, a bed device 30, and a console device 40, as in the first embodiment. The hardware configurations of the bed device 30 and the console device 40 are the same as those of the first embodiment.

[0137] Further, the X-ray tube 11 of the present embodiment includes a thermoelectron adjustment unit that adjusts the orbits of thermoelectrons. FIG. 9 is a diagram showing an example of the configuration of the X-ray tube 11 according to the second embodiment.

[0138] As shown in FIG. 9, the X-ray tube 11 of the present embodiment includes a housing (tube housing) 111, a cathode 113, a thermoelectron adjustment mechanism 114, a rotation axis 115, and an anode 116. The housing 111 is made of, for example, metal and has an X-ray window 112 that allows the X-rays generated inside to pass through. The cathode 113 generates thermoelectrons. The thermoelectrons are excited by the heat generated by the current flowing through the filament and are electrons that jump out from the filament or the heated member.

[0139] The anode 116 generates X-rays upon receiving the impact of thermoelectrons emitted from the cathode 113. Specifically, a large potential difference is provided between the cathode 113 and the anode 116. For example, by grounding the anode 116 and making the potential of the cathode 113 negative, a potential difference is provided between the cathode 113 and the anode 116. Due to this potential difference, the thermoelectrons emitted from the cathode 113 are accelerated and collide with the anode 116, generating X-rays. Also, the anode 116 is a rotating body rotated by a rotating shaft 115, and its outer periphery is circular when viewed from the axial direction of the rotating shaft 115. The anode 116 has an umbrella-like shape, with the tip side of the umbrella facing the cathode 113 side. The side of the anode 116 facing the cathode 113 is a tapered surface, forming a surface that is inclined toward the X-ray window 112 side by a certain angle with respect to the cathode 113 side. By rotating, the anode 116 disperses the positions where heat is generated due to the collision of thermoelectrons, avoiding the melting of the surface of the anode 116 due to heat generation. The rotating shaft 115 is supported by a bearing (not shown) or the like and is rotationally driven by a rotating magnetic field generated by a stator coil (not shown) or the like. Note that in FIG. 9, the trajectory of the thermoelectrons (illustrated by a dashed line) from the cathode 113 toward the anode 116 is drawn parallel to the rotating shaft 115 of the anode 116, but it is not limited to this.

[0140] The thermoelectron adjustment mechanism 114 adjusts the trajectory of the thermoelectrons under the control of the processing circuit 44. More specifically, it is provided along the trajectory of the thermoelectrons between the cathode 113 and the anode 116 so as to sandwich the trajectory, and changes the trajectory of the thermoelectrons emitted from the cathode 113 by an electric field or a magnetic field, moving the focal point on the anode 116. The thermoelectron adjustment mechanism 114 is an example of the thermoelectron adjustment unit in this embodiment.

[0141] When an electric field is used for adjusting the trajectory, the adjustment electrodes 114a, 114b are, for example, flat-plate-shaped It is an electrode or a magnetic pole of an electromagnet. Note that the hot electron adjustment mechanism 114 is not limited to being provided inside the housing 111, and the hot electron adjustment mechanism 114 may be provided outside the housing 111. In the present embodiment, the hot electron adjustment mechanism 114 has the function of an XYZ-FFS capable of changing the focal position in the XY direction and the Z direction. Also, the number, position, and direction of change of the focal position of the hot electron adjustment mechanism 114 are not limited to these.

[0142] Returning to FIG. 8, the processing circuit 44 of the console device 40 of the present embodiment includes a reception function 441, a photographing processing function 1442, an acquisition function 1443, a preprocessing function 1445, a reconstruction processing function 446, a display control function 1447, a focal position control function 448, and a synthesis function 449. The reception function 441 is an example of a reception unit. The photographing processing function 1442 is an example of a photographing processing unit. The acquisition function 1443 is an example of an acquisition unit. The preprocessing function 1445 is an example of a preprocessing unit. The reconstruction processing function 446 is an example of a reconstruction processing unit. The display control function 1447 is an example of a display control unit and an output unit. The focal position control function 448 is an example of a focal position control unit. The synthesis function 449 is an example of a synthesis unit. Each processing function is recorded in the memory 41 in the form of a program executable by a computer.

[0143] The reception function 441 and the reconstruction processing function 446 have the same functions as those in the first embodiment.

[0144] Similar to the first embodiment, the photographing processing function 1442 controls the photographing system in two types of photographing modes, an X-ray fluoroscopy photographing mode and a CT photographing mode, and performs photographing.

[0145] In addition, when performing imaging in the fluoroscopic X-ray imaging mode, the imaging processing function 1442 of the present embodiment rotates the rotating frame 13. Further, the imaging processing function 1442 causes the X-ray tube 11 to emit X-rays when the position of the X-ray tube 11 supported by the rotating frame 13 is within a specified range. That is, unlike normal CT imaging, when performing imaging in the fluoroscopic X-ray imaging mode, the X-ray tube 11 does not continuously emit X-rays, but intermittently performs imaging only when the position of the X-ray tube 11 is within the specified range. Details of the X-ray irradiation timing in the present embodiment will be described later.

[0146] During the execution of the imaging process by the imaging processing function 1442, the focal position control function 448 controls the thermoelectron adjustment mechanism 114 to switch the focal position of the thermoelectrons on the anode 116 to a plurality of different positions. In the present embodiment, the focal position control function 448 performs at least focal position switching during imaging in the fluoroscopic X-ray imaging mode. Further, the focal position control function 448 may also perform focal position switching during CT imaging.

[0147] More specifically, the focal position control function 448 changes the focal position of the thermoelectrons at a specified timing synchronized with the change in the position of the X-ray tube 11 and the X-ray detector 12 with respect to the subject P in the rotating frame 13 that rotates during imaging.

[0148] FIG. 10 is a diagram schematically showing an example of a plurality of focal positions according to the second embodiment. In FIG. 10, the central positions 61 to 65 are exemplified when X-rays from the X-ray tube 11 at different focal positions are irradiated onto a plurality of detection elements of the X-ray detector 12.

[0149] For example, the central position 61 shown in FIG. 10 is the central position of the X-rays when the X-rays are irradiated from the X-ray tube 11 to the X-ray detector 12 with the focal position at the reference position. The reference position is the default focal position in a state where the focal position has not been changed by the thermoelectron adjustment mechanism 114.

[0150] The central positions 62 to 65 of the X-rays are the central positions of the X-rays irradiated on the detection element 121a when the focal position is moved in the XY direction or the Z direction from the reference position by the thermoelectron adjustment mechanism 114, respectively. The movement in the XY direction is the movement of the focal position on the XY plane defined by the X direction and the Y direction. The XY direction is also called the fan direction. The movement in the Z direction is the movement of the focal position along the axis direction of the subject P.

[0151] In addition, in FIG. 10, among the plurality of detection elements included in the X-ray detector 12, one detection element 121a is described as an example. Similarly, for other detection elements, the central position of the irradiated X-rays changes due to the change in the focal position.

[0152] Since X-rays are irradiated at a plurality of focal positions in this way, oversampling collection becomes possible. Therefore, even if the number of detection elements does not change, the spatial resolution of the X-ray CT apparatus 1 can be improved.

[0153] Note that the number and positions of the focal positions are not limited to the example shown in FIG. 10. FIG. 11 is a diagram schematically showing another example of a plurality of focal positions according to the second embodiment. For example, the positions of the central positions 66 to 68 of the X-rays due to the focal movement may be the positions shown in FIG. 11.

[0154] Next, the change in the focal position and the X-ray irradiation timing will be described.

[0155] FIG. 12 is a diagram showing an example of the X-ray irradiation timing according to the second embodiment. The focal position control function 448 repeats the switching of the focal positions for a plurality of cycles with a combination of a plurality of focal positions defined in a specified order and number as one cycle. In FIG. 12, the first cycle to the fourth cycle are illustrated, but the number of cycles is not limited to this.

[0156] In the example shown in FIG. 12, the focal position control function 448 has one cycle with five focal positions of "XY+", "XY-", "Z+", "Z-", and "reference position".

[0157] "XY+" is the focal position moved in the XY direction from the "reference position". "XY-" is the focal position moved in the XY direction from the "reference position" in a direction different from that of "XY+". "Z+" is the focal position moved in the Z direction from the "reference position". "Z-" is the focal position moved in the Z direction from the "reference position" in a direction different from that of "Z+". In the example shown in FIG. 12, the specified order is in the order of "XY+", "XY-", "Z+", "Z-", "reference position". More specifically, among the five focal positions included in one cycle, "XY+" is the first focal position, "XY-" is the second focal position, "Z+" is the third focal position, "Z-" is the fourth focal position, and the "reference position" is the last focal position.

[0158] In the example shown in FIG. 12, since the rotating frame 13 is rotating, the position of the X-ray tube 11, that is, the view position, is changing. Assume that the period during which the view position moves by 1° is synchronized with the period of one cycle of the focal position. Specifically, as shown in FIG. 12, when the view position is 119°, the focal position becomes "XY+", the first in one cycle, and when the view position is 120°, again the focal position becomes "XY+", the first in one cycle. That is, during the period in which the view position moves by 1°, the focal position control function 448 changes the focal position by one cycle. Note that the moving speed and timing of the focal position are not limited to this.

[0159] "X-ray exposure" in FIG. 12 represents the timing at which X-rays are irradiated from the X-ray tube 11 under the control of the imaging processing function 1442. In the example shown in FIG. 12, during the 1° movement from when the view position reaches 120° to when it reaches 121°, the X-ray tube 11 irradiates X-rays. The range where the view position is from 120° to 121° is an example of the specified range of the position of the X-ray tube 11 in the present embodiment.

[0160] The time t1 shown in FIG. 12 is the start timing of X-ray irradiation, and the time t2 is the end timing of X-ray irradiation. Note that the view position at which the X-ray is irradiated may be set at an appropriate angle by the user, for example, to collect an X-ray projection fluoroscopic image of the subject P, or may be predetermined. The times t1 and t2 are examples of specified timings synchronized with the view position. In the present embodiment, the start timing and the end timing of X-ray irradiation are determined by the view position.

[0161] In FIG. 12, the period during which the view position moves by 1°, that is, the period from the beginning to the end of one cycle of the movement cycle of the focal position, is defined as the X-ray irradiation period. However, the length of the X-ray irradiation period is not limited to this. For example, the period during which the view position moves by 2° may be the X-ray irradiation period.

[0162] Only when the position of the X-ray tube 11 is within a specified range, by irradiating X-rays, the amount of X-rays irradiated can be reduced compared to the case of continuously irradiating X-rays regardless of the view position.

[0163] Returning to FIG. 8, the acquisition function 1443 acquires the projection data 91 from the DAS 18 for each focal position while the X-ray is being irradiated. In the present embodiment, since there are five focal position switches in one cycle, the acquisition function 1443 acquires five pieces of projection data 91 each time the view position changes by 1°.

[0164] The preprocessing function 1445 has the same function as in the first embodiment, and performs preprocessing on each of the plurality of pieces of projection data 91 acquired by the acquisition function 1443.

[0165] When imaging is performed in the fluoroscopic imaging mode, the synthesis function 449 generates synthesized projection data by synthesizing a plurality of pieces of projection data 91 obtained by projecting the subject P with X-rays irradiated at a plurality of different focal positions. In the present embodiment, the synthesis function 449 generates synthesized projection data by synthesizing all of the projection data 91 obtained by projecting the subject P from the start to the end of the X-ray irradiation.

[0166] More specifically, the synthesis function 449 of the present embodiment converts a plurality of pieces of projection data 91 that have been preprocessed by the preprocessing function 1445 into one piece of synthesized projection data. Note that a known technique may be adopted as a method for synthesizing the plurality of pieces of projection data 91.

[0167] The display control function 1447 has the same function as that of the first embodiment, and causes the display 42 to display the synthesized projection data as an X-ray projection fluoroscopic image.

[0168] Next, the flow of the imaging process executed by the X-ray CT apparatus 1 of the present embodiment configured as described above will be described.

[0169] FIG. 13 is a flowchart showing an example of the flow of the imaging process executed by the X-ray CT apparatus 1 according to the second embodiment.

[0170] The processes from the display of the imaging mode selection screen 421 in S101 to the reception of the imaging start operation by the user in S103 are the same as those in the first embodiment.

[0171] When the fluoroscopic imaging mode is selected by the user and the reception function 441 receives the user When the operation to start imaging by "ZA" is received (S103 "Yes"), the imaging processing function 1442 executes imaging in the fluoroscopic imaging mode (S201). In the present embodiment, the imaging processing function 1442 rotates the rotating frame 13 during imaging in the fluoroscopic imaging mode, and starts and ends the irradiation of X-rays from the X-ray tube 11 at a timing synchronized with the change in the view position of the X-ray tube 11 that changes with the rotation of the rotating frame 13. Further, the focal position control function 448 controls the thermoelectron adjustment mechanism 114 during the execution of the imaging process by the imaging processing function 1442, and changes the focal position at a timing synchronized with the change in the view position. The X-ray detector 12 collects a plurality of projection data 91 oversampled by such FFS. The DAS 18 transmits the plurality of projection data 91 collected by the X-ray detector 12 to the console device 40. The acquisition function 1443 acquires the plurality of projection data 91 transmitted from the DAS 18.

[0172] Next, the preprocessing function 1445 performs preprocessing on each of the plurality of projection data 91 acquired by the acquisition function 1443 (S202).

[0173] Then, the synthesis function 449 generates synthesized projection data by synthesizing the plurality of projection data 91 on which preprocessing has been performed (S203).

[0174] Then, the display control function 1447 displays the synthesized projection data as an X-ray projection fluoroscopic image on the display 42 (S204).

[0175] Also, when the CT imaging mode is selected by the user in the process of S102, the processes from the reception of the operation to start imaging in S113 to the reconstruction process in S116 are the same as those in the first embodiment.

[0176] Then, the display control function 1447 displays a CT image based on the CT image data 92 on the display 42 (S205).

[0177] The determination process of whether or not the imaging of S112 has been completed is the same as that in the first embodiment.

[0178] As described above, in the X-ray CT apparatus 1 of the present embodiment, during the execution of the imaging process, the focal position of the X-ray is switched to a plurality of different positions, and a plurality of projection data 91 obtained by projecting the subject P with the X-rays irradiated at the plurality of different focal positions are synthesized to generate synthesized projection data, and the synthesized projection data is displayed on the display 42 as an X-ray projection fluoroscopic image. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, in addition to the effects of the first embodiment, a high-precision X-ray projection fluoroscopic image can be generated from the projection data 91 oversampled at a plurality of focal positions.

[0179] Further, in the X-ray CT apparatus 1 of the present embodiment, the rotation frame 13 is rotated during the imaging process, and the X-ray tube 11 is irradiated with X-rays when the position of the X-ray tube 11 supported by the rotation frame 13 is within a specified range. Therefore, according to the imaging process function 1442, the amount of X-rays irradiated can be reduced as compared with the case of continuously irradiating X-rays.

[0180] Further, the X-ray CT apparatus 1 of the present embodiment changes the focal position of the X-ray at a specified timing synchronized with the change in the position of the X-ray tube 11 and the X-ray detector 12 with respect to the subject P in the rotating rotation frame 13. Therefore, according to the imaging process function 1442, the focal position of the X-ray can be changed in a cycle suitable for imaging an X-ray transmission image.

[0181] Further, in the X-ray CT apparatus 1 of the present embodiment, synthesized projection data is generated by synthesizing all the projection data 91 obtained by projecting the subject P from the start to the end of the X-ray irradiation. The display control function 447 causes the synthesized projection data to be displayed on the display 42. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, the spatial resolution of the X-ray projection fluoroscopic image can be improved as compared with the case of displaying the projection data 91 taken at a single focal position as an X-ray projection fluoroscopic image.

[0182] (Third Embodiment) In the above-described second embodiment, the X-ray irradiation timing was determined based on the view position. In this third embodiment, the X-ray irradiation timing is determined according to the user's operation.

[0183] The hardware configuration of the X-ray CT apparatus 1 of this embodiment is the same as that of the second embodiment described with reference to FIGS. 8 and 9.

[0184] Also, the processing circuit 44 of the console apparatus 40 of this embodiment includes a reception function 441, a imaging processing function 1442, an acquisition function 1443, a preprocessing function 1445, a reconstruction processing function 446, a display control function 1447, a focus position control function 448, and a synthesis function 449, similar to the second embodiment. The reception function 441 is an example of a reception unit. The imaging processing function 1442 is an example of an imaging processing unit. The acquisition function 1443 is an example of an acquisition unit. The preprocessing function 1445 is an example of a preprocessing unit. The reconstruction processing function 446 is an example of a reconstruction processing unit. The display control function 1447 is an example of a display control unit and an output unit. The focus position control function 448 is an example of a focus position control unit.

[0185] The acquisition function 1443, the preprocessing function 1445, the reconstruction processing function 446, the display control function 1447, and the synthesis function 449 have the same functions as those of the second embodiment.

[0186] The reception function 441 of this embodiment has the same functions as those of the second embodiment, and receives operations for starting and ending X-ray irradiation by the user. For example, when the foot pedal 35 is stepped on by the user, the reception function 441 receives the operation for starting X-ray irradiation by the user. Further, when the foot pedal 35 is continuously stepped on by the user, the reception function 441 continuously receives the instruction for X-ray irradiation by the user. Further, when the user stops stepping on the foot pedal 35, the reception function 441 receives the operation for ending X-ray irradiation by the user. Note that the foot pedal 35 is an example of an operation unit, and an operation button, a touch panel, or the like may be used. The operation for starting X-ray irradiation and the operation for ending X-ray irradiation may be separate operations.

[0187] The imaging processing function 1442 of this embodiment has the same functions as those of the second embodiment, and irradiates the X-ray tube 11 with X-rays according to the timing when the operation for starting X-ray irradiation by the user is received.

[0188] FIG. 14 is a diagram showing an example of X-ray irradiation timing according to the third embodiment. In FIG. 14, “Time trigger” indicates the timing of the operation for X-ray irradiation by the user. In the example shown in FIG. 14, the user starts stepping on the foot pedal 35 at time t10, and the user lifts the foot from the foot pedal 35 at time t12. Further, between time t10 and time t12, the user continuously steps on the foot pedal 35. Although the illustration of the change in the view position is omitted in FIG. 14, in this embodiment as well, it is assumed that the rotating frame 13 is rotating.

[0189] Further, the focal position control function 448 of this embodiment has the same functions as those of the second embodiment. As shown in FIG. 14, the focal position control function 448, similar to the second embodiment, sets a combination in which a plurality of focal positions are defined in a specified order and number as one cycle, and switches the focal position repeatedly for a plurality of cycles.

[0190] After the user operates to start X-ray irradiation, the imaging processing function 1442 of this embodiment starts irradiating the X-ray tube 11 with X-rays at the timing when the X-ray focal position first reaches "XY+", which is the first focal position within the cycle. In the example shown in FIG. 14, after the time t10 when the user's X-ray irradiation operation is received, the first time the focal position reaches "XY+" is the time t11. Therefore, the imaging processing function 1442 starts irradiating the X-ray tube 11 with X-rays from the time t11.

[0191] In addition, while the reception function 441 continuously receives the operation to start X-ray irradiation by the user, the imaging processing function 1442 continues to irradiate the X-ray tube 11 with X-rays. In the example shown in FIG. 14, the imaging processing function 1442 continues to irradiate the X-ray tube 11 with X-rays until at least the time t12.

[0192] Then, when the operation by the user to start X-ray irradiation ends, the imaging processing function 1442 ends irradiating the X-ray tube 11 with X-rays at the timing when the X-ray focal position switches from the last focal position within the current cycle to the first focal position within the next cycle. In the example shown in FIG. 14, after the time t12 when the user removes their foot from the foot pedal 35, the first timing when the cycle switches is the time t13. Therefore, the imaging processing function 1442 ends irradiating the X-ray tube 11 with X-rays at the time t13.

[0193] Next, the flow of the imaging process executed by the X-ray CT apparatus 1 of this embodiment configured as described above will be described.

[0194] FIG. 15 is a flowchart showing an example of the flow of the imaging process executed by the X-ray CT apparatus 1 according to the third embodiment.

[0195] Regarding the process of receiving the operation of the user to select the imaging mode in S102 from the display of the imaging mode selection screen 421 in S101, it is the same as in the first embodiment.

[0196] Then, when the X-ray fluoroscopy mode is selected, the reception function 441 of the present embodiment waits until it receives an operation to start X-ray irradiation by the user (S301 “No”).

[0197] When the reception function 441 of the present embodiment receives an operation to start X-ray irradiation by the user (S301 “Yes”), the imaging processing function 1442 of the present embodiment, after receiving the operation, when the X-ray focal position becomes the first focal position among a plurality of focal positions included in one cycle (S302 “Yes”), causes the X-ray tube 11 to emit X-rays (S303). For example, in the example illustrated in FIG. 14, the imaging processing function 1442 starts X-ray irradiation at the timing when the X-ray focal position first reaches “XY+” after the user performs an operation to start X-ray irradiation.

[0198] Also, the imaging processing function 1442 waits without causing the X-ray tube 11 to emit X-rays until the X-ray focal position reaches the first focal position among a plurality of focal positions included in one cycle after the reception function 441 receives an operation to start X-ray irradiation by the user (S302 “No”). For example, in the example illustrated in FIG. 14, the imaging processing function 1442 waits without performing X-ray irradiation until the X-ray focal position reaches “XY+” after the user performs an operation to start X-ray irradiation.

[0199] Then, the reception function 441 determines whether it has received an operation to end X-ray irradiation (S304). For example, when the user continuously presses the foot pedal 35, the reception function 441 determines that it has not received an operation to end X-ray irradiation (S304 “No”). In this case, the imaging processing function 1442 continues to irradiate the X-ray tube 11 with X-rays.

[0200] For example, when the user removes their foot from the foot pedal 35, the reception function 441 determines that it has received an operation to end X-ray irradiation by the user (S304 “Yes”). In this case, the imaging processing function 1442 waits while continuing X-ray irradiation until the timing of switching to the next cycle of the focal position (S305 “No”).

[0201] Then, after the imaging processing function 1442 receives the operation to end the X-ray irradiation by the user, when the timing of the switching of the first cycle comes (S305 “Yes”), it ends the X-ray irradiation to the X-ray tube 11 (S306).

[0202] From the preprocessing of S202 to the process of displaying the synthesized projection data of S204 as an X-ray projection fluoroscopic image on the display 42 is the same as that in the first embodiment.

[0203] Also, when the CT imaging mode is selected by the user in the process of S102, from the reception of the operation to start imaging in S113 to the reconstruction process in S116 is the same process as in the first and second embodiments. Also, the determination process of whether the imaging in S112 is completed is the same as in the first and second embodiments.

[0204] Thus, the X-ray CT apparatus 1 of this embodiment irradiates the X-ray tube 11 with X-rays according to the timing when the operation to start the X-ray irradiation by the user is received. Therefore, according to the X-ray CT apparatus 1 of this embodiment, in addition to the same effects as in the first and second embodiments, an X-ray projection fluoroscopic image can be collected at a desired timing by the user.

[0205] Also, the X-ray CT apparatus 1 of this embodiment starts irradiating the X-ray tube 11 with X-rays from the timing when the focal position of the X-rays is located at the first focal position “XY+” within the cycle for the first time after the operation to start the X-ray irradiation by the user. Therefore, according to the X-ray CT apparatus 1 of this embodiment, it is possible to start irradiating the X-rays at a timing synchronized with the cycle of the change in the focal position without the user being conscious of the cycle of the focal position.

[0206] Further, when the operation of starting the X-ray irradiation by the user is completed, the X-ray CT apparatus 1 of the present embodiment terminates the X-ray irradiation at the timing when the focal position of the X-ray switches from the last focal position within the current cycle to the first focal position within the next cycle. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, the X-ray irradiation can be terminated at a timing synchronized with the cycle of the change in the focal position without the user being aware of the cycle of the focal position.

[0207] (Fourth Embodiment) In the above-described third embodiment, when performing imaging in the X-ray fluoroscopy mode, the X-ray irradiation timing was determined in accordance with the timing of the user's operation and the timing of switching the cycle of the combination of the plurality of focal positions. In this fourth embodiment, regardless of the timing of switching the cycle, the X-ray irradiation timing is determined in accordance with the timing of the user's operation and the timing of switching in units of the focal position.

[0208] The hardware configuration of the X-ray CT apparatus 1 of the present embodiment is the same as that of the second and third embodiments.

[0209] Further, the processing circuit 44 of the console apparatus 40 of the present embodiment includes a reception function 441, an imaging processing function 1442, an acquisition function 1443, a preprocessing function 1445, a reconstruction processing function 446, a display control function 1447, a focal position control function 448, and a synthesis function 449, in the same manner as in the second and third embodiments. The reception function 441 is an example of a reception unit. The imaging processing function 1442 is , an example of an imaging processing unit. The acquisition function 1443 is an example of an acquisition unit. The preprocessing function 1445 is an example of a preprocessing unit. The reconstruction processing function 446 is an example of a reconstruction processing unit. The display control function 1447 is an example of a display control unit and an output unit. The focal position control function 448 is an example of a focal position control unit.

[0210] The acquisition function 1443, the preprocessing function 1445, the reconstruction processing function 446, the display control function 1447, and the focal position control function 448 have the same functions as those of the second embodiment.

[0211] After the user operates to start X-ray irradiation, the imaging processing function 1442 of the present embodiment starts X-ray irradiation of the X-ray tube 11 at the timing when the focal position of the X-ray first switches after the X-ray tube 11 becomes capable of X-ray irradiation.

[0212] FIG. 16 is a diagram showing an example of X-ray irradiation timing according to the fourth embodiment. As shown in FIG. 16, in the present embodiment, regardless of the switching timing of the cycle of combinations of a plurality of focal lengths, X-ray irradiation starts or ends even in the middle of the cycle.

[0213] For example, in the example shown in FIG. 16, at time t20, the user performs an operation instructing the start of X-ray irradiation, such as stepping on the foot pedal 35. Then, the user removes the foot from the foot pedal 35 at time t24.

[0214] There may be a time lag from when the user operates to instruct the start of X-ray irradiation until the X-ray tube 11 becomes capable of X-ray irradiation. In the example shown in FIG. 16, it is assumed that the X-ray tube 11 becomes capable of X-ray irradiation at time t21 after the operation instructing the start of X-ray irradiation by the user at time t20. However, time t21 does not coincide with the switching timing of the focal position. In this case, after the operation of the user to start X-ray irradiation, the timing when the focal position of the X-ray first switches after the X-ray tube 11 becomes capable of X-ray irradiation is time t23. Therefore, the imaging processing function 1442 starts X-ray irradiation of the X-ray tube 11 at the timing when the focal position switches from "Z-" to the "reference position" at time t23.

[0215] In addition, after the user's operation to end the X-ray irradiation, the imaging processing function 1442 starts the X-ray irradiation of the X-ray tube 11 at the timing when the X-ray focal position is first switched. The user's operation to end the X-ray irradiation is, for example, the operation of the user removing their foot from the foot pedal 35, similar to the third embodiment. The timing when the X-ray focal position is first switched from the time t24 when the user removes their foot from the foot pedal 35 is the time t25. Therefore, the imaging processing function 1442 ends the X-ray irradiation of the X-ray tube 11 at the time t25.

[0216] The synthesis function 449 of the present embodiment has the same functions as those of the second and third embodiments. When the X-ray irradiation period by the X-ray tube 11 spans a plurality of cycles, the synthesis function 449 synthesizes a plurality of projection data 91 obtained by the X-rays irradiated at the focal positions corresponding to the X-ray irradiation period among the plurality of focal positions included in the cycles.

[0217] More specifically, when the X-ray irradiation period starts in the middle of the first cycle of the X-ray focal position and ends in the middle of the second cycle, the synthesis function 449 selects, from among the plurality of focal positions included in the first cycle, the projection data 91 corresponding to the first focal position of the X-ray irradiation period, and from among the plurality of focal positions included in the second cycle, the other projection data 91 corresponding to the last focal position of the X-ray irradiation period. By synthesizing the continuous plurality of projection data 91 up to this point, the synthesized projection data is generated. Here, the first cycle and the second cycle are examples of a plurality of consecutive cycles and are not intended to limit the number of cycles.

[0218] In the example shown in FIG. 16, the X-ray irradiation period extends from the last focal position "reference position" of the first cycle to the fourth focal position "Z-" of the third cycle. In this case, the synthesis function 449 generates the synthesized projection data by synthesizing a total of 10 pieces of projection data 91 corresponding to each of the last focal position "reference position" of the first cycle, the first to last focal positions of the second cycle, and the first to fourth focal positions of the third cycle.

[0219] Thus, according to the X-ray CT apparatus 1 of the present embodiment, after the operation of starting the irradiation of X-rays by the user, after the X-ray tube 11 becomes capable of irradiating X-rays, the irradiation of X-rays is started on the X-ray tube 11 at the timing when the focal position of the X-rays is switched for the first time. Therefore, according to the X-ray CT apparatus 1 of the present embodiment, in addition to the same effects as those of the second and third embodiments, regardless of the timing of switching the cycle of combinations of a plurality of focal positions, since the irradiation period of X-rays can be changed, the degree of freedom of the irradiation period of X-rays by the user can be improved.

[0220] (Modification Example 1) The above-described first embodiment and the second to fourth embodiments may be combined. For example, the X-ray CT apparatus 1 of the first embodiment may have a FFS function in the same manner as the X-ray CT apparatuses 1 of the second to fourth embodiments. Specifically, similar to the X-ray CT apparatuses 1 of the second to fourth embodiments of the X-ray CT apparatus 1 of the first embodiment, it may include a thermoelectron adjustment mechanism 114, a focal position control function 448 that controls the thermoelectron adjustment mechanism 114, and a synthesis function 449 that synthesizes a plurality of projection data 91. The super-resolution processing function 444 of this modification example performs super-resolution processing on the synthesized projection data. In this case, the display control functions 447, 1447 cause the display 42 to display the synthesized projection data on which the super-resolution processing has been performed.

[0221] According to the X-ray CT apparatus 1 of this modification example, by performing super-resolution processing on the synthesized projection data in which a plurality of projection data 91 corresponding to different focal positions are synthesized, the resolution of the X-ray projection fluoroscopic image can be further improved.

[0222] (Modification Example 2) In the above-described fourth embodiment, when the irradiation period of X-rays starts in the middle of the first cycle of the focal position of X-rays and ends in the middle of the second cycle, the synthesis function 449 synthesizes the projection data 91 collected during the irradiation period of X-rays without distinguishing between the first cycle and the second cycle. The processing method for synthesizing the projection data 91 when the irradiation period of X-rays extends over a plurality of cycles is not limited to this.

[0223] For example, when the irradiation period of X-rays extends over a plurality of cycles, the combining function 449 may perform the combining process step by step so as to combine the projection data 91 for each cycle and then further combine the combined projection data with each other.

[0224] Specifically, when the irradiation period of X-rays by the X-ray tube 11 starts from the middle of the first cycle of the focal position of the X-rays and ends in the middle of the second cycle, the combining function 449 generates first combined projection data by combining one or more pieces of projection data 91 corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle. Further, the combining function 449 generates second combined projection data by combining one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle. Then, the combining function 449 generates third combined projection data by combining the first combined data and the second combined data.

[0225] The display control function 1447 of this modified example causes the third combined projection data to be displayed on the display 42 as an X-ray projection fluoroscopic image.

[0226] By such stepwise image processing, it is possible to improve the processing efficiency, such as starting the combining process of the projection data 91 corresponding to the cycle that has ended earlier before the irradiation period of the X-rays ends.

[0227] (Modified Example 3) In addition, in each of the above-described embodiments, the case where the X-ray projection fluoroscopic image taken by the X-ray CT apparatus 1 is a still image has been described as an example, but the X-ray projection fluoroscopic image may be a moving image. For example, the imaging processing functions 442 and 1442 of the X-ray CT apparatus 1 may collect a plurality of pieces of projection data 91 that are continuous in time series like a moving image by continuously imaging the subject P in the X-ray fluoroscopic imaging mode.

[0228] In this case, the display control function 447,1447 causes the display 42 to display a plurality of captured projection data 91 as X-ray projection fluoroscopic images that are continuous in time series. The X-ray projection fluoroscopic images that are continuous in time series are, for example, a moving image including a plurality of frames.

[0229] (Modification Example 4) Also, in the above-described second to fourth embodiments, it has been described that the rotating frame 13 rotates during imaging in the X-ray fluoroscopic imaging mode. However, the rotating frame 13 may be stopped during imaging in the X-ray fluoroscopic imaging mode.

[0230] The imaging processing function 1442 of this modification example, for example, in the case of the CT imaging mode, images the subject P with the rotating frame 13 rotating, and in the case of the X-ray fluoroscopic imaging mode, images the subject P with the rotating frame 13 stopped. The CT imaging mode is an example of the first imaging mode, and the X-ray fluoroscopic imaging mode is an example of the second imaging mode.

[0231] Also, in this modification example, in the X-ray fluoroscopic imaging mode, the focal position control function 448 adopts the FFS technique of switching the focal position of the X-ray to a plurality of different positions. That is, a configuration in which the rotating frame 13 stops during imaging in the X-ray fluoroscopic imaging mode as in the first embodiment and the FFS configuration of the second to fourth embodiments may be combined.

[0232] (Modification Example 5) Also, in the above-described first embodiment, the super-resolution processing execution button 73 is displayed in the same manner regardless of whether the X-ray fluoroscopic imaging mode or the CT imaging mode is selected. However, the display mode of the super-resolution processing execution button 73 may be different when the X-ray fluoroscopic imaging mode is selected and when the CT imaging mode is selected.

[0233] (Modification Example 6) Also, in the above-described first embodiment, it is assumed that the user selects whether the super-resolution processing function 444 executes the super-resolution processing. However, in the case of the X-ray fluoroscopic imaging mode, the super-resolution processing may always be executed.

[0234] (Modification Example 7) Also, in each of the above-described embodiments, the X-ray CT apparatus 1 is taken as an example of an X-ray diagnostic apparatus, but other modalities may be taken as an example of the X-ray diagnostic apparatus. For example, a PET (Positron Emission Tomography)-CT apparatus may be an X-ray diagnostic apparatus.

[0235] Also, in each of the above-described embodiments, the X-ray detector 12 is assumed to be an energy integration type, but the X-ray detector 12 may be a photon counting type X-ray detector. That is, the configuration of each of the above-described embodiments is applicable when the X-ray CT apparatus 1 is a photon counting CT apparatus. is also applicable.

[0236] (Modification Example 8) Also, in each of the above-described embodiments, part or all of the functions provided by the processing circuit 44 of the X-ray CT apparatus 1 may be provided by an information processing apparatus such as a workstation.

[0237] FIG. 17 is a diagram showing an example of a system S including a workstation 100 and an X-ray CT apparatus 1 according to Modification Example 8. As shown in FIG. 17, a workstation 100 communicably connected to the X-ray CT apparatus 1 via a network N may execute each function of the processing circuit 44 in each of the above-described embodiments. The system S is an example of a medical image diagnostic system. The X-ray CT apparatus 1 is an example of an imaging apparatus. Also, the workstation 100 is an example of a medical image processing apparatus.

[0238] When the workstation 100 includes the processing circuit 44, for example, the processing circuit 44 has an acquisition function of acquiring from the X-ray CT apparatus 1 the projection data generated in the fluoroscopic imaging mode for obtaining a fluoroscopic projection image of a subject and the CT image data generated in the CT imaging mode for obtaining a CT image of the subject. The acquisition function is an example of an acquisition unit. Further, the processing circuit 44 of the workstation 100 of the present embodiment has a super-resolution processing function 444 that executes super-resolution processing on the projection data or CT image data acquired from the X-ray CT apparatus 1. Note that the functions provided in the workstation 100 are not limited to these.

[0239] Further, the example of the medical image processing apparatus is not limited to the workstation 100. An information processing apparatus other than the workstation 100, for example, an image processing server or a server apparatus provided in a cloud environment may execute a part of the functions provided in the processing circuit 44 of each of the above-described embodiments.

[0240] (Modification Example 9) In the above-described third and fourth embodiments, the irradiation period of X-rays is determined by an operation by the user. However, the irradiation time of X-rays may be constant regardless of the duration of the user's operation. In this case, the user's operation is an operation for inputting the timing of the start of X-ray irradiation, and the irradiation of X-rays ends after a prescribed time has elapsed from the start timing. Further, when the movement of the focal position is performed for a prescribed number of cycles or a prescribed number of focal positions by the focal position control function 448 from the start timing, the imaging processing function 1442 may end the irradiation of X-rays.

[0241] (Modification Example 10) Instead of or in addition to the above-described embodiments, it is also possible to apply high-quality processing (super-resolution processing or high-quality processing by focus control) to the projection data, either in the fluoroscopic imaging mode or in the CT imaging mode. In this case, when performing super-resolution processing, since the requirements for the finally output image (fluoroscopic X-ray projection image or CT image) are different, the learned models used for super-resolution processing may be different. As a modified example of the embodiment, the super-resolution model applied to the projection data 91 obtained by imaging for a fluoroscopic X-ray projection image is a learned model trained using, as input information and / or target information, an image obtained under imaging conditions (tube current, tube voltage, gain of the X-ray detector, pixel binning setting, image processing conditions, etc.) for imaging a fluoroscopic X-ray projection image. Further, the super-resolution model applied to the projection data obtained by imaging for an X-ray CT image is a learned model trained using, as input information and / or target information, the projection data obtained under imaging conditions / scan conditions (tube current, tube voltage, gain of the X-ray detector, pixel binning setting, processing conditions for the projection data, etc.) for obtaining an X-ray CT image. The learned models for each projection data are stored in memory or implemented in hardware as separate models, and are to be used separately in the fluoroscopic imaging mode and the CT imaging mode.

[0242] The super-resolution processing function 444 of the X-ray CT apparatus 1 in this modified example changes the super-resolution model used for super-resolution processing according to the imaging mode. More specifically, when the imaging processing function 442 images the subject P in the fluoroscopic imaging mode, the super-resolution processing function 444 of the X-ray CT apparatus 1 in this modified example executes super-resolution processing on the projection data 91 using the super-resolution model applied to the projection data 91 obtained by the above-described imaging for a fluoroscopic X-ray projection image. Further, when the imaging processing function 442 images the subject P in the CT imaging mode, the super-resolution processing function 444 of the X-ray CT apparatus 1 in this modified example executes super-resolution processing on the projection data using the super-resolution model applied to the projection data obtained by the above-described imaging for an X-ray CT image.

[0243] In addition to this, in the CT imaging mode, it may also be possible to apply the super-resolution model in the CT image domain described above.

[0244] (Modification Example 11) Also, in each of the above-described embodiments, when imaging in the fluoroscopic imaging mode is performed, a projection fluoroscopic image based on the projection data collected in the fluoroscopic imaging mode is displayed on the display 42 by the display control function 447. When imaging in the CT imaging mode is performed, a CT image reconstructed based on the projection data collected in the CT imaging mode is displayed on the display 42 by the display control function 447. However, the display process is not essential.

[0245] FIG. 18 is a diagram showing an example of the configuration of the X-ray CT apparatus 1 according to Modification Example 11. For example, as shown in FIG. 18, the processing circuit 44 of the X-ray CT apparatus 1 may further include a transmitter function 450. The transmitter function 450 is an example of a transmission unit and an output unit.

[0246] For example, when a projection fluoroscopic image or a CT image is analyzed in another information processing apparatus, the transmitter function 450 transmits the projection fluoroscopic image or the CT image to the other information processing apparatus. Alternatively, the projection fluoroscopic image or the CT image may be displayed on the other information processing apparatus that is the transmission destination. Also, both the display by the display control function 447 and the transmission by the transmitter function 450 may be executed.

[0247] Note that when collectively referring to the display by the display control function 447 and the transmission by the transmitter function 450, it is called output.

[0248] (Modification Example 12) In the first embodiment described above, it was described that the imaging processing function 442 of the X-ray CT apparatus 1 performs positioning imaging in an imaging method different from the fluoroscopic imaging mode when imaging in the CT imaging mode. However, such positioning imaging is not essential.

[0249] For example, an X-ray projection fluoroscopic image obtained in the X-ray fluoroscopic imaging mode may be used as an image for positioning instead of a general positioning image. Alternatively, an image for positioning may not be used.

[0250] According to at least one of the embodiments described above, with one X-ray CT apparatus, it is possible to perform both CT image acquisition and high-precision X-ray projection fluoroscopic image acquisition.

[0251] Although several embodiments have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations of the embodiments can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

[0252] Regarding the above embodiments, the following supplementary notes are disclosed as one aspect and selective features of the invention.

[0253] (Supplementary Note 1) An imaging system that images the subject by irradiating the subject with X-rays, an imaging processing unit that controls the imaging system in any one of an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT (Computed Tomography) imaging mode for obtaining a CT image of the subject, and executes imaging of the subject, a super-resolution processing unit that executes super-resolution processing according to the imaging mode, An X-ray diagnostic apparatus comprising the same.

[0254] (Supplementary Note 2) When the imaging is executed in the X-ray fluoroscopic imaging mode, the super-resolution processing unit may execute the super-resolution processing on the projection data collected by the imaging system.

[0255] (Supplementary Note 3) The X-ray diagnostic apparatus may further include a reconstruction processing unit that reconstructs the projection data collected by the imaging system to generate CT image data. When the imaging is performed in the CT imaging mode, the super-resolution processing unit may perform the super-resolution processing on the CT image data.

[0256] (Supplementary Note 4) When the imaging in the X-ray fluoroscopy imaging mode is performed, the X-ray diagnostic apparatus outputs a projection fluoroscopy image based on the projection data collected in the X-ray fluoroscopy imaging mode for at least one of display and analysis. When the imaging in the CT imaging mode is performed, the X-ray diagnostic apparatus outputs a CT image reconstructed based on the projection data collected in the CT imaging mode for at least one of display and analysis. The X-ray diagnostic apparatus may further include an output unit.

[0257] (Supplementary Note 5) The X-ray diagnostic apparatus may further include a reception unit that receives an operation of the user for selecting whether to image the subject in either the X-ray fluoroscopy imaging mode or the CT imaging mode. The imaging processing unit may control the imaging system to image the subject in either the X-ray fluoroscopy imaging mode or the CT imaging mode according to the selection by the user.

[0258] (Supplementary Note 6) The X-ray diagnostic apparatus may further include a display control unit that causes a display unit to display an X-ray fluoroscopy imaging mode selection button capable of receiving an operation of the user for selecting the X-ray fluoroscopy imaging mode and a CT imaging mode selection button capable of receiving an operation of the user for selecting the CT imaging mode.

[0259] (Supplementary Note 7) The reception unit may receive an operation of the user for selecting whether to perform the super-resolution processing. When the execution of the super-resolution processing is selected by the user, the super-resolution processing unit may perform the super-resolution processing.

[0260] (Appendix 8) The X-ray diagnostic apparatus may further include a display control unit that receives an operation for the user to select whether to execute the super-resolution process and causes a super-resolution process execution button, which is displayed in the same manner regardless of whether the X-ray fluoroscopy mode or the CT imaging mode is selected, to be displayed on the display unit.

[0261] (Appendix 9) The imaging system a cathode that generates thermoelectrons, an anode that receives the thermoelectrons irradiated from the cathode and generates X-rays, and a thermoelectron adjuster that adjusts the trajectory of the thermoelectrons. The X-ray diagnostic apparatus may further include a focal position control unit that controls the thermoelectron adjuster to switch the focal position of the X-rays to a plurality of different positions during the execution of the imaging process by the imaging processing unit.

[0262] (Appendix 10) An X-ray tube including a cathode that generates thermoelectrons, an anode that receives the thermoelectrons irradiated from the cathode and generates X-rays, and a thermoelectron adjuster that adjusts the trajectory of the thermoelectrons, an X-ray detector that detects the X-rays irradiated from the X-ray tube and passed through the subject, an imaging processing unit that executes imaging of the subject by controlling the X-ray tube and the X-ray detector, a focal position control unit that controls the thermoelectron adjuster to switch the focal position of the X-rays to a plurality of different positions during the execution of the imaging process by the imaging processing unit, a synthesis unit that generates synthesized projection data by synthesizing a plurality of projection data in which the subject is projected by the X-rays irradiated at a plurality of different focal positions, a display control unit that causes the synthesized projection data to be displayed on a display unit as an X-ray projection fluoroscopy image, An X-ray diagnostic apparatus comprising the same.

[0263] (Appendix 11) The X-ray tube and the X-ray detector may be supported by a rotatable rotating frame. The imaging processing unit rotates the rotating frame during imaging processing, and may irradiate the X-ray tube with the X-ray when the position of the X-ray tube supported by the rotating frame is within a specified range.

[0264] (Appendix 12) The focal position control unit may change the focal position of the X-ray at a specified timing synchronized with the change in the position of the X-ray tube and the X-ray detector with respect to the subject in the rotating rotating frame.

[0265] (Appendix 13) The X-ray diagnostic apparatus may further include a reception unit that receives an operation for starting irradiation of the X-ray by a user. The X-ray tube and the X-ray detector may be supported by a rotatable rotating frame. The imaging processing unit may rotate the rotating frame during imaging processing, and may irradiate the X-ray tube with the X-ray according to the timing at which the operation for starting irradiation of the X-ray by the user is received.

[0266] (Appendix 14) The focal position control unit has a combination in which a plurality of focal positions are defined in a specified order and number as one cycle, and may repeat switching of the focal position of the X-ray for a plurality of cycles. The imaging processing unit may rotate the rotating frame during imaging processing, and may start irradiating the X-ray tube with the X-ray from the timing when the focal position of the X-ray first reaches the first focal position within the cycle after the operation for starting irradiation of the X-ray by the user.

[0267] (Appendix 15) The imaging processing unit After the operation of starting the irradiation of the X-rays by the user, after the time when the X-ray tube becomes capable of irradiating the X-rays, the irradiation of the X-rays may be started on the X-ray tube at the timing when the focal position of the X-rays is switched for the first time.

[0268] (Appendix 16) The imaging processing unit While the reception unit continues to receive the operation of starting the irradiation of the X-rays by the user, the irradiation of the X-rays may be continued on the X-ray tube. When the operation of starting the irradiation of the X-rays by the user ends, the irradiation of the X-rays may be ended at the timing when the focal position of the X-rays is switched from the last focal position within the current cycle to the first focal position within the next cycle.

[0269] (Appendix 17) The X-ray tube and the X-ray detector may be supported by a rotatable rotating frame. The imaging processing unit may execute a first imaging mode of imaging the subject with the rotating frame rotating and a second imaging mode of imaging the subject with the rotating frame stopped. In the second imaging mode, the focal position control unit may switch the focal position of the X-rays to the plurality of different positions.

[0270] (Appendix 18) The synthesis unit may generate the synthesized projection data by synthesizing all the projection data on which the subject is projected from the start to the end of the irradiation of the X-rays.

[0271] (Appendix 19) When the irradiation period of the X-rays by the X-ray tube starts from the middle of the first cycle of the focal positions of the X-rays and ends in the middle of the second cycle, the combining unit may generate the combined projection data by combining a plurality of consecutive projection data from the projection data corresponding to the first focal position during the irradiation period of the X-rays among the plurality of focal positions included in the first cycle to the projection data corresponding to the last focal position during the irradiation period of the X-rays among the plurality of focal positions included in the second cycle.

[0272] (Appendix 20) The combining unit When the irradiation period of the X-rays by the X-ray tube starts from the middle of the first cycle of the focal positions of the X-rays and ends in the middle of the second cycle, the first combined projection data may be generated by combining one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle. The second combined projection data may be generated by combining one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle. The third combined projection data may be generated by combining the first combined projection data and the second combined projection data. The display control unit may cause the display unit to display the third combined projection data as the X-ray projection fluoroscopic image.

[0273] (Appendix 21) The imaging processing unit may continuously perform imaging of the subject. The display control unit may cause the display unit to display a plurality of X-ray projection fluoroscopic image data captured by the imaging processing unit as the X-ray projection fluoroscopic images continuous in time series.

[0274] (Appendix 22) The X-ray diagnostic apparatus may further include a super-resolution processing unit that performs super-resolution processing on the combined projection data. The display control unit may cause the display unit to display the synthesized projection data subjected to super-resolution processing.

[0275] (Appendix 23) When the imaging processing unit executes imaging in the CT imaging mode, it may perform positioning imaging to obtain a positioning image for setting the imaging range of the CT image for diagnosis. In the positioning imaging, the imaging processing unit executes imaging by an imaging method different from the X-ray fluoroscopic imaging mode.

[0276] (Appendix 24) An imaging processing step of performing imaging of the subject by controlling an imaging system in an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT imaging mode for obtaining a CT image of the subject, A super-resolution processing step of performing a super-resolution processing target according to whether the subject is imaged in either the X-ray fluoroscopic imaging mode or the CT imaging mode, An X-ray diagnostic method including the above.

[0277] (Appendix 25) An imaging processing step of performing imaging of the subject by controlling an imaging system in an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT imaging mode for obtaining a CT image of the subject, A super-resolution processing step of performing a super-resolution processing target according to whether the subject is imaged in either the X-ray fluoroscopic imaging mode or the CT imaging mode, A program for causing a computer to execute the above.

[0278] (Appendix 26) An imaging processing step of irradiating the subject with X-rays by controlling an imaging system to perform imaging of the subject, A focal position control step of switching the focal position of the X-rays to a plurality of different positions during the execution of the imaging processing, A synthesizing step of generating synthesized projection data by synthesizing a plurality of pieces of projection data obtained by projecting the subject with the X-rays irradiated at a plurality of different focal positions; A displaying step of causing a display unit to display the synthesized projection data as an X-ray projection fluoroscopic image; An X-ray diagnostic method comprising the above.

[0279] (Appendix 27) A photographing processing step of irradiating a subject with X-rays by controlling a photographing system to execute photographing of the subject; A focal position control step of switching the focal position of the X-rays to a plurality of different positions during execution of the photographing processing; A synthesizing step of generating synthesized projection data by synthesizing a plurality of pieces of projection data obtained by projecting the subject with the X-rays irradiated at a plurality of different focal positions; A displaying step of causing a display unit to display the synthesized projection data as an X-ray projection fluoroscopic image; A program for causing a computer to execute the above.

[0280] (Appendix 28) An acquisition unit that acquires projection data generated by an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of a subject and CT image data generated by a CT imaging mode for obtaining a CT image of the subject; A super-resolution processing unit that executes super-resolution processing corresponding to the imaging mode on the projection data or the CT image data; A medical image processing apparatus comprising the above.

[0281] (Appendix 29) An acquisition step of acquiring projection data generated by an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of a subject and CT image data generated by a CT imaging mode for obtaining a CT image of the subject; A super-resolution processing step of executing super-resolution processing corresponding to the imaging mode on the projection data or the CT image data; A medical image processing method comprising the above.

[0282] (Supplementary Note 30) A medical imaging system comprising a imaging device and a medical image processing device, wherein the imaging device includes, an imaging system configured to irradiate a subject with X-rays to image the subject, an imaging processing unit configured to control the imaging system in any one of an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT imaging mode for obtaining a CT image of the subject, and perform imaging of the subject, and the medical image processing device is configured to perform super-resolution processing according to the imaging mode on the projection data or the CT image data acquired from the imaging device. Medical image diagnostic system.

[0283] (Supplementary Note 31) A gantry having a substantially cylindrical opening at a center portion and including an imaging system configured to irradiate a subject with X-rays to image the subject, an imaging processing unit configured to control the imaging system in any one of an X-ray fluoroscopic imaging mode for obtaining an X-ray projection fluoroscopic image of the subject and a CT imaging mode for obtaining a CT image of the subject, and perform imaging of the subject, a super-resolution processing unit configured to perform super-resolution processing according to the imaging mode, and an X-ray CT apparatus including the same.

Explanation of Reference Numerals

[0284] 1 X-ray CT apparatus 10 Gantry device 11 X-ray tube 12 X-ray detector 13 Rotating frame 14 X-ray high voltage device 15 Control device 30 Bed device 35 Foot pedal 40 Console device 41 Memory 42 Display 43 Input interface 44 Processing circuit Central positions 61 to 66 71 X-ray fluoroscopy imaging mode selection button 72 CT imaging mode selection button 73 Super-resolution processing execution button 80 Catheter 91 Projection data 92 CT image data 100 Workstation 113 Cathode 114 Thermoelectron adjustment mechanism 116 Anode 121a Detection element 421 Imaging mode selection screen 422 Super-resolution processing operation screen 423 Operation screen 441 Reception function 442, 1442 Imaging processing function 443, 1443 Acquisition function 444 Super-resolution processing function 445, 1445 Preprocessing function 446 Reconstruction processing function 447, 1447 Display control function 448 Focus position control function 449 Synthesis function 450 Transmission function P Subject S System

Claims

1. An X-ray tube including a cathode that generates thermoelectrons, an anode that generates X-rays upon receiving the thermoelectrons irradiated from the cathode, and a thermoelectron adjustment unit that adjusts the orbits of the thermoelectrons; An X-ray detector that detects X-rays irradiated from the X-ray tube and passed through a subject; An imaging processing unit that performs imaging of the subject by controlling the X-ray tube and the X-ray detector; A focal position control unit that switches the focal position of the X-rays to a plurality of different positions by controlling the thermoelectron adjustment unit during the execution of the imaging process by the imaging processing unit; A synthesis unit that generates synthesized projection data by synthesizing a plurality of projection data in which the subject is projected by the X-rays irradiated at a plurality of different focal positions; A display control unit that causes the display unit to display the synthesized projection data as an X-ray projection fluoroscopic image; Comprising; The synthesis unit: When the irradiation period of the X-rays by the X-ray tube starts from the middle of the first cycle of the focal position of the X-rays and ends in the middle of the second cycle, one or more corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle Generating first synthesized projection data by synthesizing projection data; Generating second synthesized projection data by synthesizing one or more projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle; Generating third synthesized projection data by synthesizing the first synthesized projection data and the second synthesized projection data; The display control unit causes the display unit to display the third synthesized projection data as the X-ray projection fluoroscopic image. An X-ray diagnostic apparatus.

2. The X-ray tube and the X-ray detector are supported by a rotatable rotating frame, The imaging processing unit: Rotates the rotating frame during imaging processing, When the position of the X-ray tube supported by the rotating frame is within a specified range, irradiates the X-ray tube with the X-rays. The X-ray diagnostic apparatus according to claim 1.

3. The focal position control unit changes the focal position of the X-rays at a specified timing synchronized with a change in the position of the X-ray tube and the X-ray detector with respect to the subject in the rotating rotating frame. The X-ray diagnostic apparatus according to claim 2.

4. Further comprising a reception unit that receives an operation for starting irradiation of the X-rays by a user. The X-ray tube and the X-ray detector are supported by a rotatable rotating frame, The imaging processing unit, rotates the rotating frame during imaging processing, and irradiates the X-ray tube with the X-ray according to the timing when the operation of starting the irradiation of the X-ray by the user is received. The X-ray diagnostic apparatus according to claim 1.

5. The focal position control unit repeats the switching of the focal position of the X-ray for a plurality of cycles, with a combination in which a plurality of focal positions are defined in a specified order and number as one cycle, The imaging processing unit, rotates the rotating frame during imaging processing, and starts irradiating the X-ray tube with the X-ray from the timing when the focal position of the X-ray first reaches the first focal position within the cycle after the operation of starting the irradiation of the X-ray by the user. The X-ray diagnostic apparatus according to claim 4.

6. The imaging processing unit, after the operation of starting the irradiation of the X-ray by the user, at the timing when the focal position of the X-ray first switches after the X-ray tube becomes capable of irradiating the X-ray, the X-ray tube starts irradiating the X-ray. The X-ray diagnostic apparatus according to claim 4.

7. The imaging processing unit, continues to irradiate the X-ray tube with the X-ray while the reception unit continues to receive the operation of starting the irradiation of the X-ray by the user, and when the operation of starting the irradiation of the X-ray by the user ends, ends the irradiation of the X-ray at the timing when the focal position of the X-ray switches from the last focal position within the current cycle to the first focal position within the next cycle. The X-ray diagnostic apparatus according to any one of claims 4 to 6.

8. The X-ray tube and the X-ray detector are supported by a rotatable rotating frame, The imaging processing unit executes a first imaging mode for imaging the subject with the rotating frame rotating and a second imaging mode for imaging the subject with the rotating frame stopped, In the second imaging mode, the focal position control unit switches the focal position of the X-ray to the plurality of different positions. The X-ray diagnostic apparatus according to claim 1.

9. The imaging processing unit continuously performs imaging of the subject, The display control unit causes the display unit to display a plurality of X-ray projection fluoroscopic image data captured by the imaging processing unit as the X-ray projection fluoroscopic images continuous in time series. The X-ray diagnostic apparatus according to any one of claims 1 to 8.

10. Further comprising a super-resolution processing unit that performs super-resolution processing on the synthesized projection data, The display control unit causes the display unit to display the synthesized projection data on which super-resolution processing has been performed. The X-ray diagnostic apparatus according to any one of claims 1 to 9.

11. A photographing processing step of irradiating a subject with X-rays by controlling a photographing system including an X-ray tube and an X-ray detector to perform photographing of the subject; A focal position control step of switching the focal position of the X-rays to a plurality of different positions during the execution of the photographing process; A synthesizing step of generating synthesized projection data by synthesizing a plurality of projection data obtained by projecting the subject with the X-rays irradiated at a plurality of different focal positions; A display step of causing the display unit to display the synthesized projection data as an X-ray projection fluoroscopic image; Including, In the synthesizing step, When the irradiation period of the X-rays by the X-ray tube starts from the middle of the first cycle of the focal position of the X-rays and ends in the middle of the second cycle, one or more projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle are synthesized to generate first synthesized projection data, Second synthesized projection data is generated by synthesizing one or more projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle, Third synthesized projection data is generated by synthesizing the first synthesized projection data and the second synthesized projection data, In the display step, the third synthesized projection data is displayed on the display unit as the X-ray projection fluoroscopic image. X-ray diagnostic method.

12. A photographing processing step of irradiating a subject with X-rays by controlling a photographing system including an X-ray tube and an X-ray detector to perform photographing of the subject; A focal position control step of switching the focal position of the X-rays to a plurality of different positions during the execution of the photographing process; A synthesizing step of generating synthesized projection data by synthesizing a plurality of projection data obtained by projecting the subject with the X-rays irradiated at a plurality of different focal positions; A display step of causing the display unit to display the synthesized projection data as an X-ray projection fluoroscopic image; To be executed by a computer, In the synthesizing step, When the irradiation period of the X-rays by the X-ray tube starts from the middle of the first cycle of the focal position of the X-rays and ends in the middle of the second cycle, first synthesized projection data is generated by synthesizing one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the first cycle. Second synthesized projection data is generated by synthesizing one or more pieces of projection data corresponding to one or more focal positions corresponding to the irradiation period of the X-rays among the plurality of focal positions included in the second cycle. Third synthesized projection data is generated by synthesizing the first synthesized projection data and the second synthesized projection data. In the display step, the third synthesized projection data is displayed on the display unit as the X-ray projection fluoroscopic image. Program.

Images