JP7062514B2 - X-ray CT device and X-ray tube control device - Google Patents

Description

Embodiments of the present invention relate to an X-ray CT device and an X-ray tube control device.

Conventionally, an X-ray CT device that obtains a tomographic image by irradiating a subject with X-rays and scanning the subject is known. In the X-ray CT device, a temporary error may occur due to a cause such as an abnormal discharge occurring in the X-ray tube. In this regard, it is disclosed to reduce the effects of errors when performing a helical scan that scans while moving the subject. However, in the conventional technique, when scanning with X-rays while the subject is stopped, when supplementing the detection data during the period in which the error occurred, the scanning can be performed promptly while reducing the exposure to X-rays. In some cases it could not be completed.

Japanese Unexamined Patent Publication No. 2014-236869 Japanese Patent Application Laid-Open No. 2003-135448 International Publication No. 2014/109400

The problem to be solved by the present invention is to promptly complete the scan while reducing the exposure to X-rays when supplementing the detection data during the period in which the error occurred.

The X-ray CT apparatus according to the embodiment includes an X-ray tube, an X-ray detector, a specific unit, and a control unit. The X-ray tube is supported by a rotating frame and irradiates X-rays toward the center of rotation while rotating. The X-ray detector detects the intensity of X-rays irradiated by the X-ray tube and passed through the subject. The specific unit detects that an error has occurred in the irradiation of the X-ray tube, and specifies the range of the rotation angle of the X-ray tube when the error occurs. When the specific unit detects that an error has occurred in the irradiation of the X-ray tube, the control unit continues the irradiation of the X-ray tube with the X-ray tube, and after the continuation, the X-ray detection has already been performed. The X-ray tube is stopped from irradiating X-rays in the range of the rotation angle at which the detection data is acquired by the device, and after the stop, in the range of the rotation angle of the X-ray tube when the error occurs. Error control is performed so that the X-ray tube is irradiated with X-rays.

The block diagram of the X-ray CT apparatus which concerns on embodiment. The flowchart which shows the outline of the process until the scan completion which is executed in the X-ray CT apparatus which concerns on embodiment. The figure for demonstrating the content of processing by a scan control function. The figure for demonstrating the content of the processing by the apparatus of the comparative example. A flowchart showing an example of the flow of processing executed by the scan control function (No. 1). FIG. 2 is a flowchart showing an example of the flow of processing executed by the scan control function.

Hereinafter, the X-ray CT device and the X-ray tube control device of the embodiment will be described with reference to the drawings. The X-ray CT device is a device that scans (photographs) the inside of a subject with X-rays and generates three-dimensional CT image data, a cross-sectional image, and the like. In the following description, it is assumed that the subject is introduced into the inside of the rotating frame (center of rotation) and scanned while being placed on the top plate of the bed device, but as appropriately noted, the X-ray CT device. Various modifications are possible as the embodiment of the above.

[Constitution]
FIG. 1 is a block diagram of an X-ray CT (Computed Tomography) apparatus 1 according to an embodiment. The X-ray CT device 1 includes, for example, a gantry device 10, a sleeper device 30, and a console device 40. In FIG. 1, for convenience of explanation, both a view of the gantry device 10 seen from the Z-axis direction and a view seen from the X-axis direction are shown, but in reality, the gantry device 10 is one. In the embodiment, the axis of rotation of the rotating frame 17 in the non-tilted state or the longitudinal direction of the top plate 33 of the bed device 30 is orthogonal to the Z-axis direction and the Z-axis direction, and the axis horizontal to the floor surface is the X-axis. The direction orthogonal to the direction and the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction, respectively.

The gantry device 10 includes, for example, an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high voltage device 14, an X-ray detector 15, and a data acquisition system (hereinafter, DAS: Data Acquisition System) 16. , A rotating frame 17, and a control device 18.

The X-ray tube 11 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. The X-ray tube 11 includes a vacuum tube. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermions.

The wedge 12 is a filter for adjusting the X-ray dose applied to the subject P from the X-ray tube 11. The wedge 12 attenuates the X-rays passing through itself so that the distribution of the X-ray dose applied to the subject P from the X-ray tube 11 becomes a predetermined distribution. The wedge 12 is also called a wedge filter or a bow-tie filter. The wedge 12 is made by processing aluminum so as to have a predetermined target angle and a predetermined thickness, for example.

The collimator 13 is a mechanism for narrowing the irradiation range of X-rays transmitted through the wedge 12. The collimator 13 narrows down the X-ray irradiation range by forming a slit, for example, by combining a plurality of lead plates. The collimator 13 may be called an X-ray diaphragm.

The X-ray high voltage device 14 includes, for example, a high voltage generator and an X-ray control device. The high voltage generator has an electric circuit including a transformer, a rectifier, and the like, and generates a high voltage applied to the X-ray tube 11. The X-ray control device controls the output voltage of the high voltage generator according to the X-ray dose to be generated in the X-ray tube 11. The high voltage generator may be one that boosts the voltage by the transformer described above, or may be one that boosts the voltage by an inverter. The X-ray high voltage device 14 may be provided on the rotating frame 17 or may be provided on the side of the fixed frame (not shown) of the gantry device 10. Further, the X-ray high voltage device 14 has an error detection function 14A. This will be described later.

The X-ray detector 15 detects the intensity of X-rays generated by the X-ray tube 11 and passed through the subject P and incident. The X-ray detector 15 outputs an electric signal (which may be an optical signal or the like) according to the intensity of the detected X-ray to the DAS 18. The X-ray detector 15 has, for example, a plurality of X-ray detection element trains. Each of the plurality of X-ray detection element trains is an arrangement of a plurality of X-ray detection elements in the channel direction along an arc centered on the focal point of the X-ray tube 11. The plurality of X-ray detection element sequences are arranged in the slice direction (column direction, row direction).

The X-ray detector 15 is an indirect detector having, for example, a grid, a scintillator array, and an optical sensor array. The scintillator array has a plurality of scintillators. Each scintillator has a scintillator crystal. The scintillator crystal emits light in an amount corresponding to the intensity of incident X-rays. The grid is arranged on the plane on which the X-rays of the scintillator array are incident and has an X-ray shielding plate having a function of absorbing scattered X-rays. The grid may also be called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array has, for example, an optical sensor such as a photomultiplier tube (PMT). The optical sensor array outputs an electric signal according to the amount of light emitted by the scintillator. The X-ray detector 15 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electric signal.

The DAS 16 has, for example, an amplifier, an integrator, and an A / D converter. The amplifier performs amplification processing on the electric signal output by each X-ray detection element of the X-ray detector 15. The integrator integrates the amplified electrical signal over the view period (discussed below). The A / D converter converts an electrical signal indicating the integration result into a digital signal. The DAS 16 outputs the detection data based on the digital signal to the console device 40. The detection data is a digital value of the X-ray intensity identified by the channel number, the column number, and the view number indicating the collected view of the X-ray detection element of the generator. The view number is a number that changes according to the rotation of the rotation frame 17, and is, for example, a number that is incremented according to the rotation of the rotation frame 17. Therefore, the view number is information indicating the rotation angle of the X-ray tube 11. The view period is a period within the period from the rotation angle corresponding to a certain view number to the arrival of the rotation angle corresponding to the next view number. The DAS 16 may detect the change of view by a timing signal input from the control device 18, an internal timer, or a signal acquired from a sensor (not shown). .. When X-rays are continuously exposed by the X-ray tube 11 in the case of performing a full scan, the DAS 16 collects the detection data group for the entire circumference (360 degrees). When X-rays are continuously exposed by the X-ray tube 11 in the case of performing a half scan, the DAS 16 collects detection data for a half circumference (180 degrees).

The rotating frame 17 is an annular member that supports the X-ray tube 11, the wedge 12, the collimator 13, and the X-ray detector 15 so as to face each other. The rotating frame 17 is rotatably supported by the fixed frame around the subject P introduced inside. The rotating frame 17 further supports the DAS 16. The detection data output by the DAS 16 has a photodiode provided in a non-rotating portion (for example, a fixed frame) of the gantry device 10 by optical communication from a transmitter having a light emitting diode (LED) provided in the rotating frame 17. It is transmitted to the receiver and transferred to the console device 40 by the receiver. The method of transmitting the detection data from the rotating frame 17 to the non-rotating portion is not limited to the method using the above-mentioned optical communication, and any non-contact type transmission method may be adopted. The rotating frame 17 is not limited to an annular member as long as it can support and rotate an X-ray tube 11 or the like, and may be a member such as an arm.

The X-ray CT device 1 is, for example, a Rotate / Rotate-Type X-ray CT device (third) in which both the X-ray tube 11 and the X-ray detector 15 are supported by the rotating frame 17 and rotate around the subject P. Generation CT), but not limited to this, Stationary / Rotate-Typwno X-rays in which a plurality of X-ray detection elements arranged in an annular shape are fixed to a fixed frame and the X-ray tube 11 rotates around the subject P. It may be a CT device (4th generation CT).

The control device 18 has, for example, a processing circuit having a processor such as a CPU (Central Processing Unit) and a drive mechanism including a motor, an actuator, and the like. The control device 18 receives an input signal from the input interface 43 attached to the console device 40 or the gantry device 10, and controls the operation of the gantry device 10 and the sleeper device 30. For example, the control device 18 rotates the rotating frame 17, tilts the gantry device 10, and moves the top plate 33 of the sleeper device 30. When tilting the gantry device 10, the control device 18 rotates the rotating frame 17 around an axis parallel to the Z-axis direction based on the tilt angle (tilt angle) input to the input interface 43. The control device 18 grasps the rotation angle of the rotation frame 17 by the output of a sensor (not shown) or the like. Further, the control device 18 provides the rotation angle of the rotation frame 17 to the scan control function 55 at any time. The control device 18 may be provided in the gantry device 10 or in the console device 40. Further, the processing circuit of the control device 18 has a specific function 18A. This will be described later.

The sleeper device 30 is a device on which the subject P to be scanned is placed, moved, and introduced into the rotating frame 17 of the gantry device 10. The sleeper device 30 has, for example, a base 31, a sleeper drive device 32, a top plate 33, and a support frame 34. The base 31 includes a housing that movably supports the support frame 34 in the vertical direction (Y-axis direction). The sleeper drive device 32 includes a motor and an actuator. The sleeper drive device 32 moves the top plate 33 on which the subject P is placed along the support frame 34 in the longitudinal direction (Z-axis direction) of the top plate 33. The top plate 33 is a plate-shaped member on which the subject P is placed.

The sleeper drive device 32 may move not only the top plate 33 but also the support frame 34 in the longitudinal direction of the top plate 33. Further, contrary to the above, the gantry device 10 may be movable in the Z-axis direction, and the rotation frame 17 may be controlled to come around the subject P by the movement of the gantry device 10. Further, both the gantry device 10 and the top plate 33 may be movable. Further, the X-ray CT device 1 may be a device in which the subject P is scanned in a standing position or a sitting position. In this case, the X-ray CT device 1 has a subject support mechanism instead of the sleeper device 30, and the gantry device 10 rotates the rotating frame 17 about an axial direction perpendicular to the floor surface.

The console device 40 has, for example, a memory 41, a display 42, an input interface 43, and a processing circuit 50. In the embodiment, the console device 40 will be described as a separate body from the gantry device 10, but the gantry device 10 may include a part or all of each component of the console device 40.

The memory 41 is realized by, for example, a RAM (Random Access Memory), a semiconductor memory element such as a flash memory, a hard disk, an optical disk, or the like. The memory 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, and the like. These data may be stored in an external memory with which the X-ray CT device 1 can communicate, instead of the memory 41 (or in addition to the memory 41). The external memory is controlled by the cloud server, for example, when the cloud server that manages the external memory receives a read / write request.

The display 42 displays various information. For example, the display 42 displays a medical image (CT image) generated by the processing circuit, a GUI (Graphical User Interface) image that accepts various operations by the operator, and the like. The display 42 is, for example, a liquid crystal display, a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) display, or the like. The display 42 may be provided on the gantry device 10. The display 42 may be a desktop type or a display device (for example, a tablet terminal) capable of wirelessly communicating with the main body of the console device 40.

The input interface 43 receives various input operations by the operator and outputs an electric signal indicating the contents of the received input operations to the processing circuit 50. For example, the input interface 43 includes collection conditions for collecting detection data or projection data (described later), reconstruction conditions for reconstructing a CT image, image processing conditions for generating a post-processed image from a CT image, and the like. Accepts input operations. For example, the input interface 43 is realized by a mouse, a keyboard, a touch panel, a drag ball, a switch, a button, a joystick, a camera, an infrared sensor, a microphone, and the like. The input interface 43 may be provided on the gantry device 10. Further, the input interface 43 may be realized by a display device (for example, a tablet terminal) capable of wireless communication with the main body of the console device 40.

The processing circuit 50 controls the overall operation of the X-ray CT device 1. The processing circuit 50 executes, for example, a system control function 51, a pre-processing function 52, a reconstruction processing function 53, an image processing function 54, a scan control function 55, a display control function 56, and the like. These components are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components are hardware (circuit parts) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit). It may be realized by (including circuits), or it may be realized by the cooperation of software and hardware. The program may be stored in advance in a non-transient storage device such as a memory 41, or may be stored in a removable non-transient storage medium such as a DVD or a CD-ROM. It may be installed by being attached to a drive device.

Each component of the console device 40 or the processing circuit 50 may be decentralized and realized by a plurality of hardware. The processing circuit 50 may be realized not by the configuration of the console device 40 but by a processing device capable of communicating with the console device 40. The processing device is, for example, a workstation connected to one X-ray CT device, or a device connected to a plurality of X-ray CT devices and collectively executing the same processing as the processing circuit 50 described below (the processing device). For example, a cloud server).

The system control function 51 controls various functions of the processing circuit 50 based on the input operation received by the input interface 43.

The preprocessing function 52 performs preprocessing such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, and beam hardening correction on the detection data output by DAS16, and generates and generates projection data. The projection data is stored in the memory 41.

The reconstruction processing function 53 generates and generates CT image data by performing reconstruction processing on the projection data generated by the preprocessing function 52 by a filter correction back projection method, a successive approximation reconstruction method, or the like. The CT image data is stored in the memory 41.

The image processing function 54 converts CT image data into three-dimensional image data or cross-sectional image data of an arbitrary cross section by a known method based on the input operation received by the input interface 43. The conversion to the three-dimensional image data may be performed by the preprocessing function 52.

The scan control function 55 controls the collection process of the detection data in the gantry device 10 by instructing the X-ray high voltage device 14, the DAS 16, the control device 18, and the sleeper drive device 32. The scan control function 55 controls the operation of each part when taking a picture for collecting a positioning image and taking a picture used for diagnosis. The scan control function 55 is an example of a “control unit”.

With the above configuration, the X-ray CT apparatus 1 scans the subject P in a manner such as a helical scan, a conventional scan, and a step-and-shoot. The helical scan is a mode in which the rotating frame 17 is rotated while the top plate 33 is moved to spirally scan the subject P. The conventional scan is a mode in which the rotating frame 17 is rotated with the top plate 33 stationary to scan the subject P in a circular orbit. Perform a conventional scan. The step-and-shoot is an embodiment in which the position of the top plate 33 is moved at regular intervals to perform a conventional scan in a plurality of scan areas.

FIG. 2 is a flowchart showing an outline of the processing up to the completion of scanning executed by the X-ray CT apparatus 1 according to the embodiment. The order of the processes shown in this flowchart can be changed, added, or deleted as appropriate.

First, the system control function 51 of the X-ray CT device 1 accepts the input of patient information (information of the subject P) to the input interface 43 while displaying the interface screen on the display 42 (step S100). Next, the system control function 51 accepts the selection of the target portion for the input interface 43 (step S102). For example, the display 42 displays a graphic area for selecting a target part, and the user designates the target part by selecting any of the graphic areas. Next, the system control function 51 accepts the selection of the scanning mode for the input interface 43 (step S104). Next, the system control function 51 accepts inputs of various parameters to the input interface 43 (step S106).

Next, the system control function 51 instructs the scan control function 55 to take a scanno image for positioning (step S108). The scan control function 55 instructs the X-ray high voltage device 14 and the control device 18 to photograph the subject P from two directions with the top plate 33 fixed, for example. The two directions are, for example, the X direction and the Y direction in FIG.

Next, the system control function 51 accepts the setting input of the scan plan for the input interface 43 while displaying the scanno image on the display 42 (step S110). For example, the system control function 51 accepts a scan position setting and a tilt angle setting input of the gantry device 10.

Next, the system control function 51 instructs the scan control function 55 to execute the scan (step S112). When the scan is completed, the processing of this flowchart ends.

[Error control]
The error control will be described below. The error control is executed while the scan is executed, for example, the error detection function 14A of the X-ray high voltage device 14, the specific function 18A of the control device 18, and the scan control function 55 cooperate with each other. In the above configuration, various errors (abnormalities) may occur in the irradiation of X-rays by the X-ray tube 11. Errors include abnormal discharge (also known as Spitz) and momentary outages due to momentary power outages. When these errors occur, the accuracy of the detection data (view) acquired while the error occurred becomes insufficient, and if this is used as it is for the reconstruction process, certain artifacts may occur in the cross-sectional image. There is sex. On the other hand, it is assumed that the view in which the error has occurred is corrected based on the detection results that are adjacent in time or position, but it may not be sufficiently corrected depending on the degree of the error. Therefore, in the X-ray CT apparatus 1 of the embodiment, error control is performed as follows.

A sensor for detecting the voltage, current, temperature, etc. of the X-ray tube 11 is connected to the error detection function 14A. The error detection function 14A refers to the output value of the sensor, and an error occurs in the irradiation of X-rays by the X-ray tube 11 based on the temporal change of the voltage of the X-ray tube 11 or the current flowing through the X-ray tube 11, for example. Detect what has happened. For example, the error detection function 14A detects that an error has occurred when the amount of change in voltage or current per predetermined time is equal to or greater than a predetermined value. When the error detection function 14A detects that an error has occurred, it outputs an error notification signal to the specific function 18A.

The specific function 18A collates the period during which the error notification signal is received with the rotation angle of the rotation frame 17 (in other words, the rotation angle of the X-ray tube 11), and specifies the view when an error occurs. Since the view corresponds to the rotation angle of the X-ray tube 11, such a process is nothing but a process of specifying the range of the rotation angle of the X-ray tube 11 when an error occurs. The specific function 18A outputs information (for example, a view number) indicating a view when an error occurs to the scan control function 55. The specific function 18A is an example of a “specific unit”.

The specific function 18A may be a function of the X-ray high voltage device 14. In this case, the control device 18 provides the X-ray high voltage device 14 with information on the rotation angle of the X-ray tube 11 at any time or in response to a request from the X-ray high voltage device 14. The X-ray high voltage device 14 identifies a view when an error occurs based on the timing when an error is detected by the error detection function 14A and the rotation angle information provided by the control device 18. For example, the view number is output to the scan control function 55.

When the scan control function 55 acquires the view number when an error occurs, the scan control function 55 specifies the rotation angle of the X-ray tube 11 corresponding to the view number. Then, after an error occurs, (1) the X-ray tube 11 is continuously irradiated with X-rays, and (2) after the continuation, a normal (non-error) view (detection data) is already acquired. After stopping the X-ray tube 11 to irradiate the X-ray tube 11 in the range of (3), the X-ray tube 11 is irradiated with the X-ray in the range of the rotation angle of the X-ray tube 11 when an error occurs. Let me do it.

FIG. 3 is a diagram for explaining the content of processing by the scan control function 55. In the figure, the large arrow indicates the progress of the scan. In the example of FIG. 3, the scan was started with the rotation angle of the X-ray tube 11 at the first rotation angle, and an error was detected from the second rotation angle to the third rotation angle. In this case, the scan control function 55 causes the X-ray tube 11 to continue irradiating X-rays until the X-ray tube 11 makes one rotation and the rotation angle reaches the first rotation angle. Next, the scan control function 55 stops the X-ray tube 11 from irradiating the X-ray tube 11 from the first rotation angle to the second rotation angle from which the normal view (detection data) has already been acquired, and then the scan control function 55 stops the irradiation of the X-ray tube 11. , The X-ray tube 11 is irradiated with X-rays from the second rotation angle to the third rotation angle. In the example of FIG. 3, the rotating frame 17 is assumed to rotate clockwise, but may be rotated counterclockwise.

Hereinafter, comparison with a comparative example will be described. FIG. 4 is a diagram for explaining the content of processing by the apparatus of the comparative example. In the example of FIG. 4, the rotation angle of the X-ray tube 11 in which the error is detected is in the range from the second rotation angle to the third rotation angle, as in the example of FIG. In this case, in the device of the comparative example, the X-ray tube 11 is stopped from irradiating X-rays until the first rotation angle is reached, and then the second rotation angle is reached. After reaching the angle, the X-ray tube 11 is restarted with X-ray irradiation. In this case, the scan is not completed unless the X-ray tube 11 rotates twice, which takes more time than the control of the embodiment. If the X-ray tube 11 is scanned for two rotations without stopping the X-ray irradiation, a normal view (detection data) can be obtained, but in this case, the X-ray exposure increases. Will end up. From these, according to the X-ray CT apparatus 1 of the embodiment, when complementing the view (detection data) during the period in which the error occurred, the scan can be completed promptly while reducing the exposure to X-rays. ..

The scan control function 55 may switch whether or not to execute error control depending on the operation mode of the X-ray CT device 1. FIG. 5 is a flowchart (No. 1) showing an example of the flow of processing executed by the scan control function 55. The processing of this flowchart is executed, for example, before the scanning is started.

First, the scan control function 55 refers to the information input to the input interface 43 by the start of the scan, and determines whether or not the target portion is a portion having a small motion artifact (step S200). Areas of large motion artifacts are, for example, the heart and diaphragm. The scan control function 55 refers to, for example, the list information of a part having a large motion artifact stored in the memory 41, and when the target part is a part not listed in the list information, the target part is a motion artist. It is determined that the part has a small action. On the contrary, when the list information of the small part of the motion artifact is stored in the memory 41 and the target part is the part listed in the list information, the scan control function 55 uses the motion artifact. It may be determined that it is a small part of. If the target site is not a site with small motion artifacts, the scan control function 55 determines that error control is not performed (step S206).

When it is determined that the target portion is a portion having a small motion artifact, the scan control function 55 determines whether or not the mode of the scan to be executed is a helical scan (step S202). If the aspect of the scan to be executed is not a helical scan, the scan control function 55 determines to perform error control (step S204). On the other hand, when the mode of the scan to be executed is a helical scan, the scan control function 55 determines that error control is not performed (step S206).

As described above, the scan control function 55 performs error control on condition that the target portion is a portion having a small motion artifact. This is because it is necessary to perform electrocardiographic synchronous imaging in a portion having a large motion artifact, so that the scan is often not completed in one rotation, and finer control than the error control described above is required. By such control, the X-ray CT apparatus 1 of the embodiment can perform error control only in a necessary scene.

Further, the scan control function 55 does not perform error control when the X-ray CT device 1 performs a helical scan. Since the helical scan is an embodiment in which the subject P is scanned in a spiral shape, it is difficult to suitably apply the error control described above. By such control, the X-ray CT apparatus 1 of the embodiment can perform error control only in a necessary scene.

FIG. 6 is a flowchart (No. 2) showing an example of the flow of processing executed by the scan control function 55. The processing of this flowchart chart is started at the start of scanning after it is decided to perform error control. Further, it is assumed that the rotation angle of the X-ray tube 11 at the start is the first rotation angle.

First, the scan control function 55 determines whether or not the specific function 18A has notified the view number when an error has occurred (step S300). When there is no notification of the view number when an error occurs, the scan control function 55 determines whether or not the rotation angle of the X-ray tube 11 has reached the first rotation angle (step S302). When it is determined that the rotation angle of the X-ray tube 11 has reached the first rotation angle, the scan control function 55 ends the process of this flowchart and completes the scan.

When it is determined that the view number has been notified when an error has occurred, the scan control function 55 determines whether or not the rotation angle of the X-ray tube 11 has reached the first rotation angle (step S304). When it is determined that the rotation angle of the X-ray tube 11 has reached the first rotation angle, the scan control function 55 instructs the X-ray high voltage device 14 to stop the X-ray irradiation on the X-ray tube 11 ( Step S306). In the notification, it is assumed that the content indicating that the rotation angle of the X-ray tube 11 has an error within the range from the second rotation angle to the third rotation angle is notified.

Next, the scan control function 55 determines whether or not the rotation angle of the X-ray tube 11 has reached the second rotation angle (step S308). When it is determined that the rotation angle of the X-ray tube 11 has reached the second rotation angle, the scan control function 55 instructs the X-ray high voltage device 14 to restart the X-ray irradiation to the X-ray tube 11 ( Step S310).

Next, the scan control function 55 determines whether or not the rotation angle of the X-ray tube 11 has reached the third rotation angle (step S312). When it is determined that the rotation angle of the X-ray tube 11 has reached the third rotation angle, the scan control function 55 ends the process of this flowchart and completes the scan.

In the above embodiment, at least a combination of the specific function 18A and the scan control function is an example of the “X-ray tube control device”.

In the above embodiment, the error control at the time of full scan has been described, but the error control can be similarly applied to the half scan.

According to at least one embodiment described above, the X-ray tube 11 is supported by the rotating frame 17 and emits X-rays toward the center of rotation while rotating, and is irradiated by the X-ray tube 11 and passes through the subject. The range of the rotation angle of the X-ray detector 15 that detects the intensity of the X-rays and the X-ray tube 11 that detects the occurrence of an error in the irradiation of X-rays by the X-ray tube 11 and causes an error. When the specific function 18A to be specified and the range of the rotation angle of the X-ray tube 11 when an error occurs are specified by the specific function 18A, the X-ray tube 11 is continuously irradiated with X-rays, and then the X-ray tube 11 is continuously irradiated with X-rays. The X-ray tube 11 is stopped irradiating X-rays within the range of the rotation angle at which the detection data that is not an error has already been acquired by the X-ray detector 15, and after stopping, the rotation of the X-ray tube 11 when an error occurs. By providing a scan control function 55 that performs error control to irradiate the X-ray tube with X-rays in a range of angles, exposure to X-rays is performed when supplementing the detection data during the period in which the error occurred. The scan can be completed quickly while reducing the amount.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

1 X-ray CT device 10 Stand device 11 X-ray tube 14 X-ray high voltage device 14A Error detection function 15 X-ray detector 16 DAS
17 Rotating frame 18 Control device 18A Specific function 40 Console device 50 Processing circuit 55 Scan control function

Claims (4)

An X-ray tube that is supported by a rotating frame and irradiates X-rays toward the center of rotation while rotating.
An X-ray detector that detects the intensity of X-rays that have passed through the subject and are irradiated by the X-ray tube.
A specific unit that detects that an error has occurred in the irradiation of X-rays by the X-ray tube and specifies the range of the rotation angle of the X-ray tube when the error occurs.
When the range of the rotation angle of the X-ray tube when the error occurs is specified by the specific part,
The X-ray tube is continuously irradiated with X-rays, and the X-ray tube is continuously irradiated with X-rays.
After the continuation, the X-ray tube is stopped to be irradiated with X-rays within the range of the rotation angle at which the detection data that is not an error has already been acquired by the X-ray detector.
After the stop, the X-ray tube is irradiated with X-rays within the range of the rotation angle of the X-ray tube when the error occurs.
A control unit that controls errors and
X-ray CT device. Further provided with a reception unit that receives input of information regarding a target site that irradiates the X-ray and collects the detection data.
The control unit performs the error control when the target portion is a portion to which the influence of the motion artifact is small.
The X-ray CT apparatus according to claim 1. The control unit does not perform the error control when the X-ray CT device performs a helical scan.
The X-ray CT apparatus according to claim 1 or 2. An X-ray tube supported by a rotating frame and irradiating X-rays toward the center of rotation while rotating, and an X-ray detector that detects the intensity of X-rays irradiated by the X-ray tube and passed through the subject. The X-ray CT device has a specific unit that detects that an error has occurred in the irradiation of X-rays by the X-ray tube and specifies the range of the rotation angle of the X-ray tube when the error occurs.
When the range of the rotation angle of the X-ray tube when the error occurs is specified by the specific part,
The X-ray tube is continuously irradiated with X-rays, and the X-ray tube is continuously irradiated with X-rays.
After the continuation, the X-ray tube is stopped to be irradiated with X-rays within the range of the rotation angle at which the detection data that is not an error has already been acquired by the X-ray detector.
After the stop, a control unit that performs error control for causing the X-ray tube to irradiate X-rays within the range of the rotation angle of the X-ray tube when the error occurs, and a control unit.
X-ray tube control device.

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