X-ray diagnostic equipment

Abstract

The embodiments disclosed in this specification and accompanying drawings relate to X-ray diagnostic apparatuses. The present invention provides an X-ray diagnostic apparatus that facilitates the observation of devices. The X-ray diagnostic apparatus of the embodiments includes an operation unit, a determination unit, and an irradiation control unit. The operation unit is subject to input operations performed by the operator. The determination unit determines a period of less periodic movement in the irradiation area of ​​the X-ray. The irradiation control unit, conditioned on the continued performance of the input operation, determines the start time of X-ray irradiation based on the determined period and controls it to deliver a relatively high dose of X-ray irradiation at the determined start time.

Description

[0001] Reference to related applications

[0002] This application enjoys priority to Japanese Patent Application No. 2020-206512, filed on December 14, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments disclosed in this specification and accompanying drawings relate to X-ray diagnostic apparatus. Background Technology

[0004] In endovascular interventional therapy, a therapeutic instrument (device) inserted into a blood vessel is precisely moved to the treatment site. Procedures include leaving the device in place and mechanically dilating the narrowed area by expanding the device. In this treatment method, it is necessary to determine the location of the procedure and confirm its completion. Typically, the physician refers to X-ray images generated and displayed in real time by an X-ray diagnostic device to confirm the procedure and its completion. For example, in the device, two (or sometimes one) X-ray-proof metal markers are installed as markers indicating the location of the balloon or stent. The physician refers to the markers drawn on the X-ray image displayed on the monitor to determine the location of the procedure. Furthermore, the physician refers to the device drawn on the X-ray image to confirm the completion of the procedure.

[0005] However, in endovascular interventional procedures for beating organs such as the heart, the position of devices on X-ray images is shifted. Therefore, the visual recognition of devices is poor, making it a highly demanding task for physicians to determine the location for treatment and confirm completion of the procedure by referring to X-ray images.

[0006] Therefore, techniques are known to perform deformation or alignment processing on X-ray images by tracking two-point markers drawn in sequentially generated X-ray images so that the positions of the two-point markers in each X-ray image are the same as in previous images, thereby creating a dynamic image display where the device appears to be virtually stopped. Additionally, techniques are known to emphasize the device with high contrast by, for example, averaging multiple frames of images corrected so that the positions of the two-point markers are the same in post-processing. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an X-ray diagnostic device that makes the observation of devices easier.

[0008] The X-ray diagnostic apparatus of this embodiment includes an operation unit, a determination unit, and an irradiation control unit. The operation unit is subject to input operations performed by the operator. The determination unit determines a period during which periodic movement within the X-ray irradiation area is minimal. The irradiation control unit, conditioned on the continued performance of the input operations, determines the irradiation start time of the X-rays based on the determined period and controls it to deliver a relatively high dose of X-rays at the determined irradiation start time.

[0009] Effect

[0010] The X-ray diagnostic apparatus according to the embodiment makes it easy to observe the device. Attached Figure Description

[0011] Figure 1 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus according to the first embodiment.

[0012] Figure 2 This is a flowchart showing the processing sequence of the X-ray diagnostic apparatus according to the first embodiment.

[0013] Figure 3 This is a flowchart illustrating a modified example of the processing sequence of the X-ray diagnostic apparatus according to the first embodiment.

[0014] Figure 4 This is a diagram illustrating an example of the electrocardiogram waveform and the names of the various parts in the first embodiment.

[0015] Figure 5 This is a diagram illustrating an example related to the determination of the pulse width in the first embodiment.

[0016] Figure 6 This is an example of a time chart that shows the inverse operation of the irradiation control start time considering the delay time of the first embodiment.

[0017] Figure 7 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus according to the second embodiment.

[0018] Figure 8 This is a flowchart illustrating the processing sequence of the X-ray diagnostic apparatus according to the second embodiment.

[0019] Figure 9 This is a diagram illustrating an example of a timing diagram in which the inverse operation of the irradiation control start time is performed considering the delay time of the second embodiment.

[0020] Figure 10 This is a flowchart illustrating the processing sequence of the X-ray diagnostic apparatus according to the third embodiment.

[0021] Figure 11 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus according to the fourth embodiment.

[0022] Figure 12 This is a diagram illustrating an example of a detector capable of non-destructive and multiple readouts in other embodiments. Detailed Implementation

[0023] Hereinafter, embodiments of the X-ray diagnostic apparatus will be described in detail with reference to the accompanying drawings. However, the X-ray diagnostic apparatus of this application is not limited to the embodiments shown below. Furthermore, embodiments can be combined with other embodiments and prior art within the scope of the processing content without causing contradictions. In the following description, common reference numerals are used for the same constituent elements, and repeated descriptions are omitted.

[0024] (First Implementation)

[0025] The structure of the X-ray diagnostic apparatus of the first embodiment will be described. Figure 1 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus 1 according to the first embodiment. For example... Figure 1 As shown, the X-ray diagnostic apparatus 1 includes an imaging device 10 and a console 20, connected via a system control circuit 18. The imaging device 10 includes an X-ray high-voltage device 11, an X-ray tube 12, an X-ray aperture 13, a top plate 14, an X-ray detector 15, a C-arm 16, a drive circuit 17, and a system control circuit 18. The console 20 includes a processing circuit 21, an input interface 22, a display 23, and a storage circuit 24.

[0026] Under the control of the system control circuit 18, the X-ray high-voltage device 11 supplies high voltage to the X-ray tube 12. For example, the X-ray high-voltage device 11 includes: a high-voltage generating device with circuitry such as a transformer and rectifier to generate a high voltage applied to the X-ray tube 12; and an X-ray control device to control the tube voltage, tube current, and irradiation time corresponding to the X-rays irradiated by the X-ray tube 12. Furthermore, the high-voltage generating device can be a transformer or an inverter.

[0027] X-ray tube 12 is a vacuum tube having a cathode (filament) that generates thermionic electrons and an anode (target) that generates X-rays by collisions with thermionic electrons. X-ray tube 12 uses a high voltage supplied from X-ray high-voltage device 11 to accelerate and collide thermionic electrons emitted from the cathode toward the anode, thereby generating X-rays.

[0028] The X-ray aperture 13 includes an X-ray aperture that narrows the irradiation range of the X-rays generated in the X-ray tube 12, and a filter that adjusts the X-rays irradiated from the X-ray tube 12.

[0029] The X-ray aperture in the X-ray aperture 13 has, for example, four sliding aperture blades. By sliding the aperture blades, the X-ray aperture narrows the X-rays generated by the X-ray tube 12 and directs them onto the subject P. Here, the aperture blades are plate-shaped components made of lead or the like, and are positioned near the X-ray irradiation port of the X-ray tube 12 to adjust the irradiation range of the X-rays.

[0030] The filter in the X-ray aperture 13 aims to reduce the radiation dose to the subject P and improve the image quality of the X-ray image data. It changes the quality of the transmitted X-rays according to the material and thickness of the subject P, reducing the soft-ray components that are easily absorbed by the subject P.

[0031] For example, the X-ray aperture 13 has a drive mechanism such as a motor and an actuator. Under the control of the system control circuit 18, the drive mechanism is activated, thereby controlling the X-ray irradiation. For example, the X-ray aperture 13 applies a drive voltage to the drive mechanism according to a control signal received from the system control circuit 18, thereby adjusting the opening of the aperture blades of the X-ray aperture and controlling the irradiation range of the X-rays irradiating the subject P.

[0032] The top plate 14 is a bed on which the subject P is placed, and is arranged on an examination table (not shown). The subject P is not included in the X-ray diagnostic apparatus 1. For example, the examination table has a drive mechanism such as a motor and actuators, which, under the control of the system control circuit 18, causes the drive mechanism to operate, thereby controlling the movement and tilting of the top plate 14.

[0033] The X-ray detector 15 is, for example, an X-ray flat panel detector (FPD) having detection elements arranged in a matrix. The X-ray detector 15 detects X-rays irradiating and transmitting through the X-ray tube 12 onto the subject P, and outputs a detection signal corresponding to the detected X-ray dose to the image data generation function 214. Alternatively, the X-ray detector 15 can be an indirect conversion type detector having a scintillator array and a sensor array, or a direct conversion type detector having semiconductor elements that convert incident X-rays into electrical signals. It can also be a non-destructive, multiple-readout X-ray detector, as described later.

[0034] C-arm 16 holds the X-ray tube 12, X-ray aperture 13, and X-ray detector 15 in a position that clamps the subject P. For example, C-arm 16 has a drive mechanism such as a motor and actuators, and rotates or moves under the control of system control loop 18 via drive circuit 17. Furthermore, in Figure 1 The example described uses the case where the X-ray diagnostic device 1 is a single plane, but the implementation is not limited to this and may also be a biplane.

[0035] The drive circuit 17 is implemented, for example, by a processor. The drive circuit 17 controls the C-arm 16 according to control signals received by the system control circuit 18, causing the X-ray tube 12, the X-ray aperture 13, and the X-ray detector 15 to rotate and move relative to the subject P. Alternatively, the drive circuit 17 may also be included within the system control circuit 18.

[0036] The system control circuit 18 is implemented, for example, by a processor. Under the control of the irradiation control function 213, the system control circuit 18 controls the X-ray high-voltage device 11, the X-ray tube 12, the X-ray aperture 13, the X-ray detector 15, the examination table, and the drive circuit 17, thereby controlling the overall operation of the imaging apparatus 10. For example, the system control circuit 18 controls the C-arm 16 via the drive circuit 17, causing the X-ray tube 12, the X-ray aperture 13, and the X-ray detector 15 to rotate and move relative to the subject P. Furthermore, the system control circuit 18 controls the movement of the examination table, causing the top plate 14 to move or tilt. Additionally, the system control circuit 18 controls the X-ray high-voltage device 11 according to the control signals received by the irradiation control function 213, causing the subject P to be irradiated with X-rays.

[0037] In addition, the system control circuit 18 controls the X-ray high-voltage device 11 to adjust the voltage supplied to the X-ray tube 12. Thus, the X-ray high-voltage device 11 controls the X-ray dose and on / off state of the subject P. Furthermore, the system control circuit 18 outputs the detection signal detected by the X-ray detector 15 to the storage circuit 24 for temporary storage.

[0038] For example, the system control circuit 18 controls the operation of the X-ray aperture 13, adjusting the opening degree of the aperture blades to control the irradiation range of the subject P. Additionally, the system control circuit 18 controls the operation of the X-ray aperture 13 to adjust the position of the filter, thereby controlling the dose distribution of the X-rays.

[0039] The processing circuit 21 controls the overall operation of the X-ray diagnostic apparatus 1 by executing functions 211 (determining), 212 (determining), irradiation control, 213 (irradiation control), 214 (image data generation), 215 (image processing), 216 (interpolated image generation), and 217 (display control). Specifically, the processing circuit 21 controls the system control circuit 18 and the control console 20 by executing programs corresponding to various functions from the storage circuit 24. Furthermore, the processing circuit 21 controls the overall operation of the X-ray diagnostic apparatus 1 by controlling the imaging device 10 via the system control circuit 18.

[0040] Here, the determination function 211 is an example of a determination unit. The determination function 212 is an example of a determination unit. Additionally, the illumination control function 213 is an example of an illumination control unit. Furthermore, the image data generation function 214 is an example of an image generation unit. Furthermore, the image processing function 215 is an example of an image processing unit. Moreover, the interpolation image generation function 216 is an example of an interpolation image generation unit. Finally, the display control function 217 is an example of a display control unit.

[0041] Determination function 211 determines the period with less periodic motion in the X-ray irradiation area. Specifically, determination function 211 reads from storage circuit 24 the amount of motion (coordinates) at each position in the X-ray image calculated by image processing function 215 and the period of motion based on the amount of motion, based on the X-ray image generated by image processing function 215. Based on the amount of motion and the period of motion calculated by image processing function 215, determination function 211 determines at what time (phase) the period with less variation caused by heartbeat in the X-ray irradiation area of ​​the subject P will occur next. Determination function 211 stores the processing result in storage circuit 24. In addition, the processing based on determination function 211, image data generation function 214, and image processing function 215 will be described in detail later.

[0042] The determination function 212 determines the X-ray conditions related to X-ray irradiation in the imaging apparatus 10. In this embodiment, the X-ray conditions are, for example, conditions related to the X-rays irradiated by the X-ray tube 12 and the X-ray aperture 13, such as pulse width, tube voltage, tube current, focal spot size, linear filter, and dose. Specifically, the determination function 212 determines the X-ray conditions based on the length of a period with less periodic movement determined by the determination function 211. Alternatively, for example, the determination function 212 determines the X-ray conditions based on a preset input by the operator to the input interface 22. The X-rays determined by the determination function 212 are stored in the storage circuit 24. The X-ray conditions stored in the storage circuit 24 are used for X-ray irradiation control implemented in the irradiation control function 213, which will be described later. Furthermore, the processing based on the determination function 212 will be described in detail later.

[0043] The irradiation control function 213 controls the X-ray irradiation in the imaging apparatus 10 through the system control circuit 18. Specifically, the irradiation control function 213 determines the timing of the output X-ray irradiation control signal based on the timing following a period of less periodic movement determined by the determination function 211, and the delay time required from the output X-ray irradiation control signal to the actual X-ray irradiation. Furthermore, the irradiation control function 213 controls the implementation of X-ray irradiation based on the X-ray conditions determined by the determination function 212. The processing based on the irradiation control function 213 will be described in detail later.

[0044] Image data generation function 214 uses the detection signal detected by X-ray detector 15 to generate X-ray image data and stores the generated X-ray image data in storage circuit 24. For example, image data generation function 214 performs current / voltage conversion, A / D conversion, and parallel / serial conversion on the detection signal detected by X-ray detector 15 to generate X-ray image data.

[0045] Image processing function 215 performs various image processing operations on the X-ray image data stored in storage circuit 24. For example, image processing function 215 reduces noise in the X-ray image data. Additionally, image processing function 215 degrades the X-ray image data to create other X-ray images of the same quality as the original X-ray image. The processing results of image processing function 215 are stored in storage circuit 24.

[0046] In addition, the image processing function 215 calculates the amount of motion and the period of motion in the X-ray image. Specifically, the image processing function 215 calculates the amount of motion at each location in the X-ray image through various image processing steps and stores it in the storage circuit 24. Furthermore, based on the calculated amount of motion, the image processing function 215 calculates the period of motion and stores it in the storage circuit 24. The processing based on the image processing function 215 will be described in detail later.

[0047] The interpolation image generation function 216 generates an interpolated image for X-ray image data consisting of multiple frames and X-ray images stored in the storage circuit 24. For example, the interpolation image generation function 216 generates an interpolated image that interpolates between the final frame of multiple X-ray images obtained in the determination function 211 during a period with less periodic movement of the observed object and an X-ray image generated by X-ray irradiation with a relatively high dose. The interpolated image generated in the interpolation image generation function 216 is stored in the storage circuit 24. Further details regarding the processing based on the interpolation image generation function 216 will be described later.

[0048] Display control function 217 causes display 23 to display a GUI or X-ray image. For example, display control function 217 reads an X-ray image from storage circuit 24 based on operations via input interface 22 and displays it on display 23. Additionally, display control function 217 via... Figure 1 The network (not shown) is used to control the sending and receiving of data with external devices.

[0049] Input interface 22 accepts various input operations from the operator, converts the accepted input operations into electrical signals, and outputs them to processing circuit 21. For example, input interface 22 can be implemented using a mouse, keyboard, trackball, switch, button, joystick, touchpad (where input is performed by touching the operating surface), touchscreen (where the display screen and touchpad are integrated), contactless input circuit using optical sensors, or voice input circuit. Furthermore, input interface 22 can also be constructed from a tablet terminal capable of wireless communication with the main device. In addition, input interface 22 is not limited to interfaces with physical operating components such as a mouse or keyboard. For example, processing circuits that receive electrical signals corresponding to input operations from external input devices separate from the device and output these electrical signals to processing circuit 21 are also included in the example of input interface 22.

[0050] Display 23 displays various information. For example, under the control of display control function 217, display 23 displays a GUI for receiving operator instructions and various X-ray images stored in storage circuit 24. Additionally, display 23 displays the processing results of processing circuit 21. For example, display 23 displays X-ray images generated by image processing function 215 after high-dose X-ray irradiation. Furthermore, display 23 displays various X-ray images stored in storage circuit 24 and displays image information so that the user can identify the type of X-ray image.

[0051] The storage circuit 24 is implemented, for example, using semiconductor memory elements such as RAM (Random Access Memory), flash memory, hard disks, or optical disks. The storage circuit 24 temporarily stores the processing results of the processing circuit 21. For example, the storage circuit 24 receives and temporarily stores image data generated by the image data generation function 214. Additionally, the storage circuit 24 stores various data and programs used by the processing circuit 21. Specifically, the storage circuit 24 is connected to the processing circuit 21, storing data input from the processing circuit 21, or reading stored data and outputting it to the processing circuit 21. Alternatively, the storage circuit 24 can also be implemented using a server cluster (cloud) connected to the X-ray diagnostic device 1 via a network.

[0052] The above describes an example of the structure of the X-ray diagnostic apparatus 1 according to this embodiment. Based on this structure, the X-ray diagnostic apparatus 1 can facilitate the observation of devices in endovascular interventional therapy through the processing circuit 21. Specifically, the X-ray diagnostic apparatus 1 determines the period during which the fluctuations caused by the heartbeat of the subject P in the region of interest are minimal, determines the optimal X-ray conditions based on the determined period, and performs X-ray irradiation. As a result, observation of devices in the region of interest whose visual discernibility is reduced due to the beating of the heart, etc., becomes easier.

[0053] As described above, in endovascular interventional treatment, the X-ray diagnostic device can indicate the position of the device by displaying X-ray images of X-ray-insensitive metals that are marked at two locations on the device. Furthermore, the X-ray diagnostic device detects the marked pairs of the device, aligns and adds the images in a way that cancels motion caused by the beating of the heart or the like, and performs image processing, thereby enabling the condition of devices such as stents that are usually difficult to observe to be represented in a single, easily observable image.

[0054] However, the method of facilitating device observation through the detection of marker pairs is not always feasible. For example, the method cannot be implemented if the device with the marker pair is not in the area of ​​interest. Specifically, when moving a stent while using a catheter with a marker pair as a guide, the marker pair installed on the catheter is used to confirm the position and condition of the stent. After stent placement, the catheter used as a guide becomes unnecessary, and the operator removes it from the body, leaving the catheter absent in the area of ​​interest. Therefore, after stent placement, the catheter with the marker pair is absent in the area of ​​interest, and the X-ray diagnostic device 1 cannot detect or align the stent in the generated X-ray image, thus failing to ascertain the stent's position and condition.

[0055] Furthermore, there are situations where reduced detection accuracy of the marker pairs makes it impossible to create images that are easy to observe the devices. For example, when background components such as organs and bones in the X-ray image overlap with the markers, reducing detection accuracy, the marker contrast decreases due to factors such as the speed of device movement in the X-ray image, the thickness of the subject, and X-ray conditions, making marker pair detection difficult. Alternatively, when the frame rate of the X-ray diagnostic device is low relative to the movement of the marker pairs, or when the X-ray image is magnified and the field of view is narrow, the amount of movement per frame is large, making it impossible to correctly perform marker pair detection.

[0056] Therefore, the X-ray diagnostic apparatus 1 of this embodiment does not use marker pairs, but instead determines a period in the X-ray irradiation area during which there is less movement caused by the beating of the heart, etc., determines the X-ray conditions based on this period and performs X-ray irradiation with a relatively high dose (high-dose X-ray irradiation), thereby generating an image that makes observation of the device easier.

[0057] Here, the processing sequence of the X-ray diagnostic device 1 is explained. Figure 2 This is a flowchart illustrating the processing sequence of the X-ray diagnostic apparatus 1 according to the first embodiment. Hereinafter, an overview of each step in the flowchart will be given first, followed by a detailed explanation of the processing in each step. Figure 2 Steps S101 to S102 are implemented by the circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. In step S103, the processing circuit 21 reads from the storage circuit 24 and executes the program corresponding to the illumination control function 213 and the image data generation function 214. Step S104 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 211 and the image processing function 215.

[0058] Furthermore, step S105 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 211. Steps S106 and S107 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 212. Steps S108 and S110 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. In step S111, the processing circuit 21 reads from the storage circuit 24 and executes the program corresponding to the display control function 217, the image data generation function 214, and the image processing function 215. Steps S112 and S113 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. Step S114 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 212. In addition, step S115 is achieved by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the irradiation control function 213.

[0059] like Figure 2 As shown, in the X-ray diagnostic apparatus 1 of the first embodiment, the processing circuit 21 determines whether a termination operation (step S101) has been performed for the mode (high-dose X-ray irradiation mode) that involves a series of processes for high-dose X-ray irradiation. If a termination operation has been performed (step S101: Yes), the X-ray diagnostic apparatus 1 terminates the process. On the other hand, if a termination operation for the high-dose X-ray irradiation mode has not been performed (step S101: No), the input interface 22 receives an input operation (e.g., pressing a switch for X-ray irradiation), and the processing circuit 21 determines whether such an input operation has been performed (step S102). If no input operation has been performed (step S102: No), the processing circuit 21 returns to step S101.

[0060] On the other hand, when an input operation is performed (step S101: Yes), the processing circuit 21 controls the imaging device 10 to perform perspective and generate a perspective image (step S103). Then, the processing circuit 21 calculates the amount of motion and the period of motion at each position for the perspective image (step S104). Furthermore, the processing circuit 21 uses the calculated amount of motion and the period of motion to estimate the next time period of smaller periodic motions will occur, and determines whether the estimation is complete (step S105).

[0061] Here, if the estimated time of occurrence of a periodic motion with a small magnitude has not been completed (step S105: No), the X-ray conditions for the next pulse are determined (step S114). Then, the processing circuit 21 determines whether an input operation has been performed (step S115). If an input operation has been performed (step S115: Yes), a fluoroscopic image is obtained. On the other hand, if no input operation has been performed (step S115: No), the processing circuit 21 terminates the processing.

[0062] If the estimated time of occurrence of the periodic motion is completed in step S105 (step S105: Yes), the processing circuit 21 determines the pulse width of the X-ray irradiated in step S110 (step S106) based on the estimated period of the periodic motion and a preset value. Then, the processing circuit 21 determines the X-ray conditions other than the pulse width (step S107).

[0063] Next, the processing circuit 21 determines the irradiation control start time and the irradiation start time based on the delay time required from the output X-ray irradiation control signal to the actual irradiation of X-rays (step S108).

[0064] Then, the processing circuit 21 determines whether an input operation has been performed (step S109). If no input operation has been performed (step S109: No), the processing ends. On the other hand, if an input operation has been performed (step S109: Yes), the processing circuit 21 controls the imaging device 10 to perform high-dose X-ray irradiation according to the irradiation start time determined in step S108 (step S110). Then, the processing circuit 21 uses the detection signal detected by the relatively high dose of X-rays irradiated by the imaging device 10 to generate a relatively high-dose X-ray image, and displays the generated X-ray image (high-dose X-ray image) on the display 23 (step S111).

[0065] Next, the processing circuit 21 determines whether an input requesting a change in conditions and re-enhancing high-dose X-ray irradiation has been received at the input interface 22 (step S112). If the processing circuit 21 receives an input requesting a change in conditions for high-dose X-ray irradiation (step S112: Yes), it accepts the condition change input (step S113). For example, the processing circuit 21 accepts an input requesting a change in X-ray conditions including pulse width. Then, the processing circuit 21 returns to step S101 and performs processing. On the other hand, if the input requesting a change in conditions for high-dose X-ray irradiation is not received (step S112: No), the processing circuit 21 terminates the processing related to the high-dose X-ray irradiation mode.

[0066] In addition, Figure 2In the processing sequence shown, an example is given where processing ends if no input operation is performed during the determination of whether the operator has performed an input operation (e.g., step S109). However, it is also possible for the processing flow to return to the start if no input operation is performed during the aforementioned determination. Figure 3 This is a flowchart illustrating a modified example of the processing sequence of the X-ray diagnostic apparatus 1 according to the first embodiment. Additionally, Figure 3 and Figure 2 Compared to the flowchart shown, the difference is that it does not include the post-determination processing in step S109 and step S115. The following explanation will focus on these two aspects.

[0067] like Figure 3 As shown, in the modified X-ray diagnostic apparatus 1, regarding steps S101 to S108, and... Figure 2 The same process is performed. Then, if no input operation is determined in step S109 (step S109: No), the processing circuit 21 returns to step S101 and performs the process. On the other hand, if an input operation is performed (step S109: Yes), the processing circuit 21 and... Figure 2 Similarly, high-dose X-ray irradiation is performed (step S110).

[0068] Furthermore, in the modified X-ray diagnostic apparatus 1, when the X-ray conditions for the next pulse are determined in step S114, the process returns to step S102 for execution. Additionally, in the modified X-ray diagnostic apparatus 1, steps S110 to S113 are also... Figure 2 The same processing is performed. According to the above variation, for example, when a situation occurs where input operations cannot continue, it is possible to determine the termination of processing according to the operator's intention.

[0069] The processing of the X-ray diagnostic apparatus 1 according to the first embodiment will be described in detail below. Furthermore, in the first embodiment, as a process for determining times with less periodic movement, the case of using fluoroscopic images to determine periods with less variation caused by heartbeats will be described as an example.

[0070] The X-ray diagnostic apparatus 1 of the first embodiment performs fluoroscopy while the operator's input operation continues. For each location in the collected fluoroscopic image, it determines a period with less periodic movement caused by the heartbeat. The X-ray diagnostic apparatus 1 determines the time to start X-ray irradiation control (the time of outputting the irradiation control signal) and the time to perform X-ray irradiation according to the determined period (the actual irradiation time), and performs X-ray irradiation with a relatively high dose. Thus, the X-ray diagnostic apparatus 1 displays X-ray images that improve the visual recognizability of the device while suppressing the decrease in visual recognizability caused by the heartbeat. Furthermore, if the operator stops the input operation to stop X-ray irradiation, the process is stopped.

[0071] (Input Interface)

[0072] The input interface 22, which accepts continuous input from the operator, can be, for example, an input interface like a foot switch or hand switch found in a typical X-ray diagnostic apparatus, which the operator presses at a desired time to control X-ray irradiation. Alternatively, for example, to distinguish between the series of X-ray irradiation processes implemented in this embodiment and the series of processes implemented in a normal X-ray irradiation, the input interface 22 can be a dedicated switch used only in the series of processes of this embodiment. Furthermore, the input operations of this embodiment can also be implemented by assigning functions to a function switch that the operator can arbitrarily assign functions to.

[0073] Alternatively, the input interface 22 may also include a switch for switching between a normal X-ray irradiation mode (normal X-ray irradiation mode) and a high-dose X-ray irradiation mode (high-dose X-ray irradiation mode) that does not perform high-dose X-ray irradiation according to this embodiment. Specifically, when the operator selects the high-dose X-ray irradiation mode via the switch, the switch that was assigned to perform the normal X-ray irradiation function in the normal X-ray irradiation mode may be assigned to perform the X-ray irradiation function based on the high-dose X-ray irradiation mode.

[0074] Furthermore, the input interface 22 accepts prior input of X-ray conditions related to X-ray irradiation. For example, before placing the subject on the top plate 14 of the X-ray diagnostic apparatus, the operator can pre-set X-ray conditions based on the subject's body thickness and the apparatus specifications of the X-ray diagnostic apparatus 1. Moreover, in this embodiment, X-ray conditions can be specified for either fluoroscopy or relatively high-dose X-ray irradiation. Thus, after performing a high-dose X-ray irradiation mode, the X-ray conditions corresponding to variations in the subject can be determined and irradiated within the range of X-ray conditions specified by the operator.

[0075] (Continuation of input operation)

[0076] As described above, the processing circuit 21 performs a series of processes to execute high-dose X-ray irradiation conditioned on an input operation. That is, when the high-dose X-ray irradiation mode is selected, the operator operates the X-ray diagnostic device 1 from acquiring the fluoroscopic image to performing a relatively high dose of X-ray irradiation and displaying it on the screen simply by continuously inputting the operation. For example, if the switch for X-ray irradiation is continuously pressed, a high-dose X-ray image can be displayed by performing the same operation as in the normal X-ray irradiation mode. In other words, the operator instructs the X-ray diagnostic device to perform X-ray irradiation only once during the process, reducing the operator's workload. Furthermore, if the input operation is not continuous, the processing in the high-dose X-ray irradiation mode is terminated, thereby preventing unnecessary X-ray irradiation and reducing the radiation dose.

[0077] (Collection of perspective images)

[0078] As described above, in step S103, the processing circuit 21 performs fluoroscopy during a period consisting of multiple heartbeats and collects fluoroscopic images. Specifically, the irradiation control function 213 in the processing circuit 21 outputs an irradiation control signal, thereby sequentially irradiating X-rays with a relatively low dose comparable to that of fluoroscopy. Here, the X-ray conditions for fluoroscopy can be pre-input (preset) via the input interface 22, or can be determined using Automatic Brightness Control (ABC). ABC is a control that feeds back statistical values ​​of pixel values ​​in the fluoroscopic image (e.g., the average value of pixels in the area of ​​interest) to the X-ray conditions of the next frame of fluoroscopy, and brings these statistical values ​​close to the target value. For example, X-ray conditions such as tube voltage, tube current, pulse width, and linear filter in the collection of fluoroscopic images can also be appropriately set via ABC. The convergent X-ray conditions under ABC reflect the average X-ray absorbance of the subject, so by using the results obtained by adjusting the X-ray conditions via ABC during fluoroscopy, it is possible to estimate the incident dose required to obtain the necessary image quality in high-dose X-ray images.

[0079] The image data generation function 214 uses the detection signal detected by the X-ray detector 15 to generate X-ray image data and stores it in the storage circuit 24. Additionally, the period consisting of multiple heartbeats can be, for example, about three heartbeats, but to improve the accuracy of determining the amount of motion or the period of motion, fluoroscopy can be performed during a period of more than three heartbeats.

[0080] (Estimation of times with fewer periodic movements)

[0081] In step S104, the determination function 211 calculates the amount of motion and the period of motion in the perspective image, which is composed of multiple frames and generated in step S103, at each position via the image processing function 215. Here, the determination function 211 reads from the storage circuit 24 the amount of motion at each position in the X-ray image calculated by the image processing function 215 based on the generated X-ray image, and the period of motion based on the amount of motion. Then, in step S105, the determination function 211 estimates the time when the periodic motion is less (the period with relatively less motion) and the start and end time of the next time interval, i.e., it estimates the start and end times.

[0082] Furthermore, in the first embodiment, the determining function 211 determines a period of relatively small motion based on the amount of motion in the fluoroscopic image without using electrocardiogram waveform information. A period of relatively small motion is, for example, equivalent to... Figure 4The ECG waveform shown represents a period of relatively small variation in the ECG waveform during a single heartbeat, similar to the period between the T and P waves. However, since the subject's heartbeat condition changes constantly, the period of minimal variation caused by the heartbeat does not necessarily need to correspond to the period between the T and P waves. Furthermore, Figure 4 This is a diagram illustrating an example of the electrocardiogram waveform and the names of the various parts in the first embodiment.

[0083] In this first embodiment, the X-ray diagnostic apparatus 1 determines a period of relatively small motion based on the amount of motion in a fluoroscopic image depicting the heart's beating state after X-ray irradiation. The period of relative stillness between contraction and expansion of the heart, which occurs repeatedly, is a period of relatively small variation in the electrocardiogram waveform during one heartbeat. In a healthy human body, this period occurs periodically with each heartbeat. Furthermore, in this embodiment, the period of relatively small motion is determined based on a fluoroscopic image composed of multiple frames. Therefore, even with an increased frame rate during imaging, it is difficult to fully observe the variations caused by the heartbeat, and the period of relatively small motion is not strictly determined.

[0084] In the method for calculating motion in image processing function 215, there is a method that calculates motion by performing inter-frame differencing and optical flow on a perspective image consisting of multiple sequentially collected X-ray images. For example, in the case of calculating motion by inter-frame differencing, image processing function 215 performs inter-frame differencing between temporally adjacent frames in a perspective image (multiple frames) composed of multiple sequentially collected X-ray images, thereby calculating the motion in the perspective image between two adjacent frames. That is, image processing function 215 takes multiple sequentially collected frames as objects and calculates the aforementioned motion between two adjacent frames respectively.

[0085] Then, the image processing function 215 determines the shift of motion in multiple frames based on the motion quantities calculated between two adjacent frames, and calculates the period of motion based on the determined shift of motion quantities. Specifically, the image processing function 215 calculates the period of times when the motion quantity is low during the shift of motion quantity. For example, the image processing function 215 extracts the times when the motion quantity is below a threshold, the periods when the motion quantity is continuously below the threshold, and the times when the motion quantity exceeds the threshold during the shift of motion quantity. Thus, the image processing function 215 calculates the period of times when the motion quantity is continuously below the threshold during the shift of motion quantity.

[0086] Furthermore, the aforementioned shift in motion intensity can be calculated either across the entire image or per region. Additionally, the threshold used for comparison with motion intensity can be arbitrarily determined. For example, the threshold for comparison with motion intensity can be determined for each individual subject.

[0087] Additionally, for example, when calculating motion through optical flow, image processing function 215 determines the shift in motion based on displacement vectors representing the motion of objects in temporally adjacent frames across multiple frames. Then, image processing function 215 extracts from the shift in motion the times when the motion is below a threshold, the periods during which the motion is continuously below the threshold, and the times when the motion exceeds the threshold, thereby calculating the period during which the motion is continuously below the threshold.

[0088] The determination function 211 determines the occurrence time of a period with relatively little motion on the time axis of image acquisition based on the motion amount and motion period calculated by the image processing function 215. For example, the determination function 211 determines the frame corresponding to a period in which the motion amount calculated by the image processing function 215 is continuously below a threshold. Furthermore, the determination function 211 determines the frame corresponding to the moment in which the motion amount is below the threshold in the determined frame as the start time of the period with relatively little motion, and determines the frame corresponding to the moment in which the motion amount exceeds the threshold as the end time of the period with relatively little motion.

[0089] Here, the variation based on heartbeats is considered not to be constant, but rather different with each heartbeat. Therefore, the determination function 211, for example, takes multiple frames of three heartbeats as objects, and extracts the frames corresponding to the start and end times of the relatively less motion period, as described above, to determine the occurrence times among the multiple frames. That is, the determination function 211 extracts three frames corresponding to the start time of the relatively less motion period and three frames corresponding to the end time from multiple frames of three heartbeats.

[0090] Then, the determination function 211 estimates the start time of a subsequent period with relatively little motion based on the occurrence times of the three frames extracted with respect to the start time. Additionally, the determination function 211 estimates the end time of a subsequent period with relatively little motion based on the occurrence times of the three frames extracted with respect to the end time. That is, while continuously collecting perspective images, the determination function 211 determines frames corresponding to the start time of a subsequent period with relatively little motion and frames corresponding to the end time of a period with relatively little motion.

[0091] Here, the determination function 211 can also perform preprocessing to appropriately calculate the amount of motion in the X-ray image caused by the changes due to the heartbeat via the image processing function 215. As an example of preprocessing, for instance, by creating X-ray image data after removing background components such as organs and bones, as well as noise components, and calculating the amount of motion based on the created X-ray image data, the accuracy of the amount of motion can be improved. Specifically, the image processing function 215 removes low-frequency components by performing filtering processing on the X-ray image data to remove background components, obtaining X-ray image data with residual signal components. Furthermore, the image processing function 215 removes more high-frequency components from the obtained X-ray image data, which contain more subtle noise that is easily affected when appropriately calculating motion, thereby obtaining X-ray image data with mid-frequency components. By using the X-ray image data obtained in this way as the object, the amount of motion can be calculated by focusing on the signal information containing the observed object within the signal information contained in the X-ray image.

[0092] Here, the object of motion calculation is the perspective image. Since the operator pre-defines the irradiation area, the probability that the region of interest exists at the edge of the X-ray image is low. Therefore, the motion can be weighted according to its coordinates in the image, with a smaller weighting coefficient closer to the image edge. For example, when the motion at the image edge is active, sometimes the motion at the edge is greater than the motion in the region of interest. Even in such cases, by weighting the motion, the reduction in the accuracy of motion calculation due to movement at the image edge can be prevented. Furthermore, to calculate motion with high accuracy, the frame rate of the perspective can be increased.

[0093] Furthermore, when the object of observation is an X-ray-non-transmissive device, the device can be depicted in the X-ray image even without a marker. Therefore, the image processing function 215 can also limit the calculation of motion to the region containing the device in the X-ray image. That is, the determination function 211 can also control the image processing function 215 to segment the X-ray image into X-ray-non-transmissive devices and other areas, and limit the calculation of motion to the region. Thus, by limiting the calculation of motion to the periphery of the object of observation, i.e., the X-ray-non-transmissive device, and determining the period of relatively small motion based on the period of motion, the determination function 211 can prevent the influence of motion from parts that are not the object of observation. Furthermore, the determination function 211 can shorten the time required to calculate the motion.

[0094] (Determination of pulse width)

[0095] Then, in step S106, based on the determined period of the periodic motion and the X-ray conditions pre-input by the input interface 22, the determination function 212 determines the pulse width of the X-ray irradiated in step S110. The pulse width is the period during which one pulse of X-ray is applied to obtain one X-ray image. Figure 5 This is a diagram illustrating an example related to the determination of the pulse width in the first embodiment. For example, when the illumination control function 213 performs fluoroscopy with three heartbeats, during the period of the next heartbeat, the determination function 211 determines the period with less periodic movement. Then, as... Figure 5 As shown, the determination function 212 sets the pulse width of the X-ray in a manner that includes periods with less periodic motion.

[0096] For example, such as Figure 5 As shown, the determination function 212 determines the pulse width of X-ray irradiation based on the periodic movement of the subject from 4 to 2 heartbeats before the fluoroscopic image, during a period when the movement is relatively small and the device is easy to observe. However, due to the specifications of the X-ray tube 12 and other devices, there are limits to the pulse values ​​that can be achieved, so the determination function 212 may not be able to determine the pulse width in a way that is smaller than the period when the periodic movement is small.

[0097] Additionally, the operator can preset the minimum and maximum values ​​of the pulse width via the input interface 22. For example, if the dose of X-rays output from the X-ray tube 12 is already determined, the pulse width at which the dose output is guaranteed can be set to the minimum value to limit the pulse width so as not to be smaller than the minimum value.

[0098] Furthermore, if the X-ray conditions for fluoroscopy in step S103 are determined by ABC, the pulse width can also be determined based on the adjustment results of ABC. For example, the determination function 212 can also calculate the incident dose required to obtain the necessary image quality in a high-dose X-ray image based on the adjustment results of ABC, and set the pulse width in such a way that the X-ray pulse is contained within a determined period of small periodic motion and that the necessary incident dose can be ensured according to the device specifications (i.e., the limitations related to the available X-ray conditions).

[0099] Alternatively, the determination function 212 can also determine the pulse width based on the relationship between the pulse width during fluoroscopy and the motion blur in one frame of the fluoroscopic image. That is, in a fluoroscopic image composed of multiple sequentially collected X-ray images, the determination function 212 determines the pulse width during the relatively high dose of X-ray irradiation performed by the imaging device 10 in step S110, based on the pulse width during fluoroscopy and the motion blur generated in one frame of the fluoroscopic image. Furthermore, the motion blur can be appropriately calculated using known methods.

[0100] Here, the pulse width in perspective is a value pre-input via input interface 22 or a value determined by ABC, and determination function 212 obtains the pulse width in perspective from storage circuit 24. In addition, determination function 212 takes the perspective image obtained by determination function 211 during a period of relatively little motion determined using the perspective image as the object, and obtains the motion blur generated in each frame of the perspective image calculated by image processing function 215.

[0101] Then, the determination function 212 compares the motion blur of the fluoroscopic image calculated by the image processing function 215 with the allowable value of motion blur. Here, the allowable value of motion blur is the value of motion blur that is permissible in a high-dose X-ray image, and is preset by the operator. The determination function 212 can determine the pulse width of the relatively high-dose X-ray irradiation performed in step S110 based on the relationship between the motion blur of the fluoroscopic image when the pulse width in fluoroscopy is a certain value and the allowable value of motion blur. Here, the fluoroscopic image compared with the allowable value of motion blur is not limited to the fluoroscopic image corresponding to a period with relatively little motion, but can also be the entire fluoroscopic image during the period of fluoroscopy.

[0102] For example, if the motion blur of the fluoroscopic image is below the permissible value, the determination function 212 determines the pulse width of the relatively high dose X-ray irradiation to be the same as the pulse width of the fluoroscopy. Conversely, if the motion blur of the fluoroscopic image exceeds the permissible value, the determination function 212 changes the determination of the pulse width of the relatively high dose X-ray irradiation to a value smaller than the pulse width of the fluoroscopy. That is, when the motion blur of the fluoroscopic image is below the permissible value, the determination function 212 determines that the pulse width of the relatively high dose X-ray irradiation can be set to the same value as the pulse width in the fluoroscopy, and determines the pulse width accordingly. However, if the motion blur of the fluoroscopic image exceeds the permissible value, and the pulse width used during fluoroscopy is used, the same motion blur would occur during the relatively high dose X-ray irradiation, which is insufficient; therefore, the pulse width of the relatively high dose X-ray irradiation is changed to a smaller value.

[0103] For example, when a perspective view with a pulse width of A is performed during the period of three heartbeats, in step S103, perspective images consisting of multiple frames from the three heartbeats are collected sequentially. Then, determination function 212 obtains perspective images from the perspective images consisting of multiple frames from the three heartbeats that correspond to the period with relatively little motion. For example, if there are five perspective images in the perspective images during the period with relatively little motion in the first heartbeat, determination function 212 determines whether the motion blur of each of the five perspective images is below the allowable value. If the motion blur of all five frames is below the allowable value, it can be determined that the perspective view performed during the period with relatively little motion in the first heartbeat is a perspective view performed without causing motion blur exceeding the allowable value. Determination function 212 performs the same determination for the three heartbeats, determining whether the perspective view performed during the three periods with relatively little motion is performed without causing motion blur exceeding the allowable value.

[0104] If the result of determining whether the motion blur in the fluoroscopic image corresponding to a period of relatively little motion during three heartbeats is below the allowable value exceeds the allowable value, the large pulse width A in the fluoroscopy is considered as a reason. Therefore, the determination function 212 sets the pulse width to reduce the pulse width in the relatively high dose X-ray irradiation to, for example, about 80% of the pulse width A in the fluoroscopy. However, since the patient's heartbeat status changes constantly, the period of relatively little motion at the time of fluoroscopy gradually changes, and there are cases where this period is earlier or later than the time of relatively high dose X-ray irradiation. At this time, relatively large motion may actually occur during the period determined to be a period of relatively little motion. Therefore, the time of implementing the relatively high dose X-ray irradiation (irradiation start time) can also be changed based on the frequency of motion blur values ​​exceeding the allowable value.

[0105] (Other X-ray conditions)

[0106] In step S107, the determination function 212 determines X-ray conditions other than the pulse width (other X-ray conditions). Specifically, the determination function 212 determines the tube voltage, tube current, focal spot size, linear filter, and the dose of the target to be detected by the detector. Based on the pulse width determined in step S105, the determination function 212 prioritizes the focal spot size and tube voltage under X-ray conditions to achieve the dose required for X-ray irradiation. The method for determining X-ray conditions can be the same as the usual method for determining X-ray conditions. Alternatively, the determination function 212 can also determine X-ray conditions based on presets input by the operator to the input interface 22. Or, if the X-ray conditions for fluoroscopy are determined by ABC in step S103, the determination function 212 can also determine other X-ray conditions based on the adjustment results of ABC. For example, in step S103, if the required incident dose for high-dose X-ray irradiation is calculated based on the adjustment results of ABC and the corresponding pulse width is set, the determination function 212 may also determine other X-ray conditions in step S107 in a way that ensures the necessary incident dose at the set pulse width.

[0107] Following the pulse width determined in step S106, determination function 212 prioritizes determining the focal size and tube voltage under other X-ray conditions. Similar to determining normal X-ray conditions, for both focal size and tube voltage, determination function 212 sets the tube voltage to prevent excessively high levels in order to reduce the focal size and prevent focal blurring. Furthermore, the X-ray diagnostic device has multiple (e.g., three) focal sizes. Therefore, to achieve the target dose for the X-ray, determination function 212 selects and determines the focal size from, for example, the three, based on the pulse width determined in step S106.

[0108] (Pulse configuration)

[0109] As described above, the determining function 212 determines the pulse width in such a way that the pulse width is smaller than the period of relatively small periodic motion. Here, the variation caused by the heartbeat also exists during periods of relatively large motion. That is, periods of relatively large motion exist before and after periods of relatively small motion, and these periods alternate. Therefore, the closer the start and end times of periods of relatively small motion are, the higher the probability of being affected by motion.

[0110] Therefore, the irradiation control function 213 configures the pulse in a manner unaffected by the movement before and after the relatively short period of movement. That is, the irradiation control function 213 determines the irradiation start time for the pulse whose pulse width is determined by the determination function 212, in a manner that does not affect the movement before and after the relatively short period of movement. For example, the irradiation control function 213 determines the start time of the relatively short period of movement as (0% of the relatively short period of movement has elapsed) and the end time of the relatively short period of movement as (100% of the relatively short period of movement has elapsed). In this case, the irradiation control function 213 determines the irradiation start time by configuring the pulse so that its center is located at a position corresponding to a set elapsed time % (e.g., 50%) within the relatively short period of movement.

[0111] Furthermore, even within periods of relatively small motion, there are moments of small motion and moments of large motion. To generate X-ray images with higher visual clarity, the irradiation control function 213 can also control the X-ray irradiation to avoid periods of large variation within periods of relatively small motion.

[0112] To avoid performing X-ray irradiation during periods of relatively small motion with large variations, for example, the irradiation control function 213 determines the start time of X-ray irradiation based on the amount of motion between the start and end times of the relatively small motion period. For example, the irradiation control function 213 sets the start time of the relatively small motion period as (0% of the relatively small motion period has elapsed) and the end time of the relatively small motion period as (100% of the relatively small motion period has elapsed). Here, it is assumed that there is significant variation within the period of 0% to 10% of the relatively small motion period. Furthermore, the determined pulse width is assumed to be 80% of the length of the relatively small motion period.

[0113] In this case, the irradiation control function 213, in order to avoid the period of relatively small motion passing through 0% to 10%, for example, determines the irradiation start time as the time point (when 20% of the period of relatively small motion has passed). If the irradiation start time is determined as described above, the start time of X-ray irradiation becomes the time point when 20% of the period of relatively small motion has passed, and the end time becomes the time point when 100% of the period of relatively small motion has passed.

[0114] Furthermore, if the pulse width determined by the determination function 212 exceeds the length of the period with relatively small motion, the illumination control function 213 configures the pulse in a manner that can further avoid the influence of motion. In this case, for example, the illumination control function 213 determines the illumination start time by referring to the amount of motion in frames before and after the period with relatively small motion, in a manner that configures the pulse on the side with less motion.

[0115] (The start time of irradiation control and the determination of the start time of irradiation)

[0116] In step S108, the irradiation control function 213 determines the irradiation control start time and the irradiation start time based on the delay time required from the irradiation control signal outputting X-rays to the actual irradiation of X-rays. Furthermore, the irradiation control start time and the irradiation start time determined by the irradiation control function 213 are applied to the X-ray irradiation control executed in step S110.

[0117] Figure 6 This is a diagram illustrating an example of a timing diagram in which the inverse operation of the irradiation control start time is performed considering the delay time of the first embodiment. Here, in Figure 6 In the past, the electrocardiogram (A) of the subject was used to represent the motion in the X-ray image caused by the beating of the subject's heart. However, in this embodiment, the electrocardiogram is not used.

[0118] Figure 6 The irradiation control signal (B) in the diagram represents the signal output by the irradiation control function 213, and X-rays are irradiated according to this irradiation control signal (B). Furthermore, Figure 6 In the text, X-ray irradiation (C) refers to irradiation by X-rays emitted from X-ray tube 12 according to the irradiation control signal (B). Additionally, Figure 6 The image processing function (D) corresponds to the processing based on image processing function 215, representing the generation of an X-ray image (fluoroscopic image, X-ray image collected at a relatively high dose, etc.) corresponding to X-ray irradiation (C). Furthermore, Figure 6 The determination function (E) in the figure corresponds to the processing based on determination function 211, which represents the determination of a period with less periodic motion based on the perspective image generated by the image processing function (D).

[0119] For example, the X-ray diagnostic apparatus 1 of the first embodiment starts irradiation control by outputting an irradiation control signal (B), thereby... Figure 6 As shown in X-ray irradiation (C), X-rays are sequentially irradiated with relatively low doses at a set pulse width. Additionally, in Figure 6 In the diagram, only one illumination control signal (B) is shown for collecting perspective images, but in reality, the illumination control signal is output for illuminating each pulse.

[0120] Furthermore, the X-ray diagnostic apparatus 1 generates fluoroscopic images corresponding to each pulse based on the sequentially executed X-ray irradiation, and determines a period with less periodic movement based on the generated multiple fluoroscopic images. Here, in the first embodiment, the period with less periodic movement is determined based on the fluoroscopic images. Therefore, the irradiation control function 213 determines the aforementioned irradiation start time by using information about when X-ray irradiation was performed on the time axis based on the multiple fluoroscopic images determined as the period with less periodic movement, thereby enabling X-ray irradiation to be performed during the period with less periodic movement in the actual subject. Thus, for example, as... Figure 6 As shown in X-ray irradiation (C), pulse P1 is set for periods with less periodic movement within the actual subject.

[0121] Furthermore, the irradiation control function 213 determines the start time of irradiation control by pulse irradiation during periods of less periodic movement within the actual subject. In the X-ray diagnostic apparatus 1, there exists a delay time required from the output of the irradiation control signal (B) until actual X-ray irradiation. Figure 6 The time t1). Therefore, in order to achieve a pulse set during a period with less periodic movement in the actual subject through the above processing, it is necessary to consider the delay time required from the output X-ray irradiation control signal to the actual X-ray irradiation.

[0122] Therefore, the irradiation control function 213 determines the irradiation control start time as the time point t1 before the start time of the pulse set during a period with less periodic movement within the actual subject. That is, the irradiation control function 213... Figure 6 As shown in the irradiation control signal (B), the irradiation control signal is output at a time point before the start of the pulse set during a period when there is less periodic movement within the actual subject. Therefore, during periods when there is less periodic movement within the actual subject, X-rays can be irradiated with a relatively high dose.

[0123] In addition, the delay time (time t1) required from the output X-ray irradiation control signal to the actual X-ray irradiation can be calculated from the actual control state in the X-ray diagnostic device 1, or it can be the time input in advance via the input interface 22.

[0124] (High-dose X-ray irradiation)

[0125] In step S110, at the irradiation control start time determined in step S108, the irradiation control function 213 initiates the irradiation control, irradiating X-rays at the irradiation start time. Specifically, the irradiation control function 213 outputs a control signal based on the X-ray conditions, the irradiation control start time, and the irradiation start time determined in steps S106 to S108, to perform a relatively high dose of X-ray irradiation. When the irradiation control function 213 outputs the control signal, the imaging device 10 performs a relatively high dose of X-ray irradiation.

[0126] (Display of high-dose X-ray images)

[0127] In step S111, the display control function 217 displays a relatively high-dose X-ray image (high-dose X-ray image) generated based on the detection signal detected by the X-ray detector 15 on the display 23. The operator observes the high-dose X-ray image displayed on the display.

[0128] Additionally, when multiple fluoroscopic images collected during a period of relatively small motion are temporarily saved and displayed as a moving image along with a high-dose X-ray image, the interpolation image generation function 216 can also generate an interpolated image. In this case, for example, the interpolation image generation function 216 can determine the fluoroscopic image corresponding to the phase between the last collected fluoroscopic image and the high-dose X-ray image among multiple consecutively collected fluoroscopic images, and generate an interpolated image using the determined fluoroscopic image. The display control function 217 can display the interpolated image generated by the interpolation image generation function 216.

[0129] (Changes in conditions of high-dose X-ray irradiation)

[0130] In step S112, the irradiation control function 213 determines whether a change input operation has been accepted at the input interface 22. For example, when performing a series of processes from steps S101 to S111 and displaying a high-dose X-ray image on the monitor, due to certain influences, the X-ray irradiation may sometimes occur at a time when the operator is affected by changes in heart rate. In this case, the operator first observes the high-dose X-ray image displayed on the monitor. If the operator determines that X-ray irradiation needs to be performed again, they input a change to the irradiation start time and X-ray conditions via the input interface 22. Here, the input change of conditions is stored in the storage circuit 24. The irradiation control function 213 retrieves the operator's change input from the storage circuit 24 and controls the system to perform a series of processes again from step S101 based on the content of the change input.

[0131] For example, if motion blur occurs in a high-dose X-ray image displayed on the monitor, the operator determines that the pulse width needs to be adjusted. At this time, the operator inputs a change to the pulse width into input interface 22. The X-ray diagnostic device 1 then performs the processing again.

[0132] Furthermore, in the above embodiment, the following situation was described: a period of relatively little motion was determined based on a fluoroscopic image of 3 heartbeats, the fourth heartbeat was the processing time, and a relatively high dose of X-ray irradiation was performed during the fifth heartbeat. However, the embodiment is not limited to this. For example, the processing may be performed based on the accuracy of determining the period of relatively little motion, the delay time required from the start of X-ray irradiation control to the generation of the X-ray image, which may be predetermined according to the specifications of the device, etc. For example, a fluoroscopic image equivalent to a period of less than 2 heartbeats or more than 4 heartbeats may be used to determine the period of relatively little motion. In addition, for example, it may be possible to wait for a processing time of more than 2 heartbeats after the period of relatively little motion has been determined.

[0133] In the first embodiment described above, the processing circuit 21, the driving circuit 17, and the system control circuit 18 can also be regarded as a single unit and understood as "processing circuit".

[0134] As described above, according to the first embodiment, the input interface 22 is subject to input operations performed by the operator. The determination function 211 determines a period of less periodic movement within the X-ray irradiation area. The irradiation control function 213, conditioned on continuous input operations by the operator, determines the start time of X-ray irradiation based on the period of less periodic movement, and controls the irradiation at the determined start time to deliver a relatively high dose of X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment, while the operator's input operations are continuous, determines a period of relatively less movement based on the periodic movement within the irradiation area and sequentially executes the process until a relatively high dose of X-ray irradiation is delivered. Thus, the operator can easily observe the device without performing cumbersome operations.

[0135] Furthermore, the X-ray diagnostic apparatus 1 of the first embodiment observes the device in real time via fluoroscopic images of the X-ray irradiation area where fluctuations occur due to the patient's heartbeat, and determines in which phase of the next timeframe a period of relatively little movement will occur. Based on the determined period, it determines the optimal X-ray conditions and irradiates with a high dose of X-rays. Therefore, the X-ray diagnostic apparatus 1 can acquire a high-dose X-ray image at the optimal time for each patient, based on the patient's current condition, and can obtain X-ray images from which the device can be easily observed from any patient.

[0136] Furthermore, according to the first embodiment, the image data generation function 214 sequentially generates X-ray images based on X-rays irradiating and passing through the subject from the X-ray tube. The determination function 211 determines the period with less periodic motion based on the multiple X-ray images sequentially generated by the image data generation function 214. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can perform X-ray irradiation and, based on the multiple sequentially generated X-ray images, determine in real time in which phase the period with less periodic motion will occur next.

[0137] Furthermore, according to the first embodiment, the determination function 212 determines the X-ray conditions based on the duration of the input operation and on periods with less periodic movement. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can determine the X-ray conditions taking into account periods with less periodic movement, and can perform X-ray irradiation suitable for observation of the device.

[0138] Furthermore, according to the first embodiment, the determination function 212 determines the pulse width based on the length of the period with less periodic motion. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can determine the time of X-ray irradiation during the period with less influence from motion, and can set X-ray conditions that are more suitable for the observation of the device.

[0139] Furthermore, according to the first embodiment, the determination function 212 determines the focal spot size based on the length of the period with less periodic motion and the target dose. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment has less influence from motion and can achieve the dose for appropriate device mapping, and can set X-ray conditions suitable for device observation.

[0140] Furthermore, according to the first embodiment, the determination function 211 calculates the degree of periodic motion at each location in the X-ray images based on multiple X-ray images. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can calculate the periodic motion at each location based on multiple X-ray images, and can determine with high precision in which phase a period with less periodic motion will occur next.

[0141] Furthermore, according to the first embodiment, the determination function 211 calculates the degree of motion based on the magnitude of the periodic motion at each location in multiple X-ray images and the weighting coefficients corresponding to each location. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can determine the degree of motion in an appropriate region (including the region containing the device, etc.) in an X-ray image, and can determine with higher accuracy in which phase a period with less periodic motion will occur next.

[0142] Furthermore, according to the first embodiment, the determination function 212 determines the pulse width related to a relatively high dose of X-ray irradiation based on the duration of the input operation, the pulse width during X-ray irradiation when generating multiple X-ray images, and the motion blur in the multiple X-ray images. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can determine the pulse width related to a relatively high dose of X-ray irradiation based on the relationship between the pulse width in the actually collected X-ray images and the motion blur generated by X-ray irradiation, in a manner that does not exceed the allowable value of motion blur, and can set X-ray conditions more suitable for the observation of the device.

[0143] Furthermore, according to the first embodiment, the irradiation control function 213 determines the irradiation start time based on the time required from the output of the control signal instructing the output of a relatively high dose of X-ray irradiation to the commencement of X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can determine the timing of outputting the irradiation control signal based on the delay time required from the output of the X-ray irradiation control signal to the actual commencement of X-ray irradiation, and can set the irradiation start time of the actual commencement of X-ray irradiation to be optimal.

[0144] Furthermore, according to the first embodiment, the input interface 22 accepts an input operation to switch to an irradiation mode that provides a relatively high dose of X-ray irradiation before accepting the input operation continues. Therefore, in the X-ray diagnostic apparatus 1 of the first embodiment, the operator can easily perform the switching of the mode corresponding to the need, and can switch from the normal X-ray irradiation mode to the irradiation mode that provides a relatively high dose of X-ray irradiation without performing cumbersome operations.

[0145] Furthermore, according to the first embodiment, the input interface 22 accepts change input operations performed by the operator that relate to at least one of the irradiation start time and X-ray conditions, based on the state of the relatively high-dose X-ray image obtained through relatively high-dose X-ray irradiation. The irradiation control function 213 controls the execution of relatively high-dose X-ray irradiation with changes to at least one of the irradiation start time and X-ray conditions, according to the change input operation. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can perform re-irradiation according to the change input related to X-ray irradiation when the operator determines that it is necessary to perform relatively high-dose X-ray irradiation again, and can perform re-irradiation suitable for observation of the device.

[0146] Furthermore, according to the first embodiment, the display control function 217 causes the display 23 to display a relatively high dose X-ray image obtained through relatively high dose X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the first embodiment can display the obtained relatively high dose X-ray image, allowing the operator to observe the device and determine whether re-irradiation is necessary.

[0147] (Second Implementation)

[0148] In the first embodiment described above, an example is given of using perspective images to determine periods with minimal fluctuations caused by heartbeats. In the second embodiment, an example is given of using electrocardiogram waveform information to determine periods with minimal fluctuations caused by heartbeats. Figure 7 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus 1 according to the second embodiment. Furthermore, compared to the X-ray diagnostic apparatus 1 of the first embodiment, the X-ray diagnostic apparatus 1 of the second embodiment has an electrocardiograph 2 connected to it. The X-ray diagnostic apparatus 1 acquires electrocardiogram waveform information from the electrocardiograph 2 via the acquisition circuit 30. In this respect, the processing content of the determination function 211 and the irradiation control function 213 differs. The following description will focus on these aspects.

[0149] like Figure 7 As shown, in the second embodiment, the X-ray diagnostic device 1 is connected to the electrocardiograph 2, and the X-ray diagnostic device 1 acquires electrocardiogram (ECG) waveform information via the ECG 2 through the acquisition circuit 30. Here, the ECG waveform information includes the ECG waveform of the subject measured by the ECG 2 and a timestamp information recording the time when the ECG waveform occurred.

[0150] The electrocardiogram (ECG) machine 2 acquires the electrocardiogram (ECG) waveform information of the subject and sends the acquired ECG waveform information along with timestamp information to the acquisition circuit 30. The acquisition circuit 30 is connected to the control console 20, acquires the ECG waveform information collected by the ECG machine 2, and stores the ECG waveform information in the storage circuit 24 of the control console 20. Here, the acquisition circuit 30 can establish a correspondence between the time information of the acquired ECG waveform information and the ECG waveform information for storage.

[0151] The determination function 211 of the second embodiment determines a period with less periodic movement based on the electrocardiogram waveform of the subject. Then, the irradiation control function 213 of the second embodiment determines the irradiation control start time and the irradiation start time for the period with less periodic movement determined by the electrocardiogram waveform.

[0152] Here, the processing sequence of the X-ray diagnostic apparatus of the second embodiment will be explained first. Figure 8 This is a flowchart illustrating the processing sequence of the X-ray diagnostic apparatus 1 according to the second embodiment. Additionally, in Figure 8 In the processing sequence shown, an example is given where the processing ends if no input operation is performed in the determination of whether the operator has performed an input operation. However, in the above determination, the processing flow can also return to the beginning if no input operation is performed.

[0153] Figure 8 Step S201 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the irradiation control function 213. Step S202 is implemented by reading from the storage circuit 24 and executing the program corresponding to the acquisition circuit 30. Step S203 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 211. Step S204 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the irradiation control function 213.

[0154] Furthermore, steps S205 to S206 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the decision function 212. Steps S207 to S209 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. Step S210 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the display control function 217, the image data generation function 214, and the image processing function 215. Steps S211 and S212 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213.

[0155] like Figure 8 As shown, in the X-ray diagnostic apparatus 1 of the second embodiment, the processing circuit 21 determines whether a high-dose X-ray irradiation mode termination operation has been performed (step S201). If a termination operation has been performed (step S201: Yes), the X-ray diagnostic apparatus 1 terminates processing. On the other hand, if a high-dose X-ray irradiation mode termination operation has not been performed (step S201: No), the acquisition circuit 30 acquires electrocardiogram (ECG) waveform information (step S202). Then, based on the ECG waveform information, the processing circuit 21 determines the next occurrence of a period of relatively small movement (step S203). Then, when the input interface 22 receives an input operation, the processing circuit 21 determines that the input operation is continuous (step S204). If the input operation is not continuous (step S204: No), the processing circuit 21 returns to step S201 and then determines whether a continuous input operation has been received.

[0156] On the other hand, while the input operation continues (step S204: Yes), the processing circuit 21 determines the pulse width of the X-ray irradiated in step S209 (step S205) based on the determined period of smaller periodic movement and the X-ray conditions (preset) input in advance through the input interface 22. Furthermore, the processing circuit 21 determines X-ray conditions other than the pulse width (step S206).

[0157] Next, the processing circuit 21 determines the irradiation control start time and the irradiation start time based on the delay time required from the output X-ray irradiation control signal to the actual X-ray irradiation, and the delay time required from the acquisition of the electrocardiogram waveform by the electrocardiograph 2 to its transmission to the acquisition circuit 30 (step S207). Then, the processing circuit 21 determines whether an input operation has been performed (step S208). If no input operation has been performed (step S208: No), the processing ends. On the other hand, if an input operation has been performed (step S208: Yes), the processing circuit 21 controls the imaging device 10 to perform high-dose X-ray irradiation along the irradiation start time determined in step S207 (step S209).

[0158] Then, the processing circuit 21 uses the detection signal detected by the imaging device 10 irradiating a relatively high dose of X-rays to generate a high-dose X-ray image, and displays the generated high-dose X-ray image on the display 23 (step S210).

[0159] Next, the processing circuit 21 determines whether the input interface 22 has accepted an input requesting a change in conditions and a re-enactment of high-dose X-ray irradiation (step S211). If the processing circuit 21 accepts the input requesting a change in conditions for high-dose X-ray irradiation (step S211: Yes), it accepts the condition change input (step S212). Then, the processing circuit 21 returns to step S201 and performs processing. On the other hand, if the input requesting a change in conditions for high-dose X-ray irradiation is not accepted (step S211: No), the processing circuit 21 terminates the processing related to the high-dose X-ray irradiation mode.

[0160] (Determining the time when periodic motion is less frequent)

[0161] As described above, in step S203, the determination function 211 of the second embodiment determines the period of relatively small motion based on the electrocardiogram waveform information related to the subject. Specifically, the electrocardiograph 2 continuously collects the electrocardiogram waveform information of the subject, and the determination function 211 determines the period of relatively small motion based on the electrocardiogram waveform information acquired by the acquisition circuit 30, and stores the determined result in the storage circuit 24. In the second embodiment, the period of relatively small motion refers to, for example... Figure 4 The period between the T wave and P wave in the electrocardiogram (ECG) waveform is a relatively small period of change in the ECG waveform during one heartbeat.

[0162] For example, the determination function 211 determines the T wave and P wave in the electrocardiogram waveform acquired by the acquisition circuit 30. Moreover, the determination function 211 determines the moment when the T wave declines as the beginning of a period with less periodic movement, and determines the moment just before the P wave rises as the end of a period with less periodic movement.

[0163] However, in cases where high-precision acquisition of ECG waveforms is not possible due to certain factors, the determination function 211 can also determine periods with less periodic motion based on periods with relatively large motion that are generally easy to acquire, similar to the interval between R waves (RR interval). For example, when determining periods with less periodic motion based on the (RR interval) of the ECG waveform, the determination function 211 determines the R waves in the ECG waveform acquired by the acquisition circuit 30. Furthermore, the determination function 211 calculates the period of the ECG waveform based on the length of the (RR interval) and collects the relative magnitude of motion based on the changes in the ECG waveform, thereby determining periods with less periodic motion.

[0164] Here, function 211 can also be defined as follows: Figure 8 As shown in the flowchart, immediately after the electrocardiograph 2 is installed on the subject, the period of less periodic movement is determined and specific processing is continuously performed. Alternatively, the determination function 211 may not determine the period of consistently less periodic movement, or it may determine the period of less periodic movement after the moment the operator has performed an input operation.

[0165] (The start time of irradiation control and the determination of the start time of irradiation)

[0166] As described above, when the period with less periodic movement (the period with relatively small movement) is determined by the determining function 211, the determining function 212 determines the pulse width and other X-ray conditions in the same way as in the first embodiment. Furthermore, the irradiation control function 213, in the same way as in the first embodiment, configures the pulse for the period with relatively small movement.

[0167] Then, in step S207, the irradiation control function 213 determines the irradiation control start time and the irradiation start time based on the delay time required from the irradiation control signal outputting X-rays to the actual irradiation of X-rays, and the delay time required from the acquisition of electrocardiogram waveforms by electrocardiograph 2 to the transmission to the acquisition circuit 30.

[0168] Figure 9This is an example of a timing diagram showing an inverse operation of the irradiation control start time, taking into account the delay time from the X-ray irradiation time in the second embodiment. Here, Figure 9 The electrocardiogram waveform (A) in the figure represents the electrocardiogram waveform acquired by the electrocardiograph 2 before being transmitted to the acquisition circuit 30. Additionally, Figure 9 The electrocardiogram waveform (B) in the figure represents the electrocardiogram waveform after transmission to the acquisition circuit 30. As described above, in the second embodiment, a period of relatively small motion is determined based on the electrocardiogram waveform, but the transmitted electrocardiogram waveform is as follows: Figure 9 As shown, the transmission time is delayed relative to the electrocardiogram waveform obtained from the subject. Figure 9 The waveform at time t2).

[0169] Figure 9 The irradiation control signal (C) in the diagram represents the signal output by the irradiation control function 213, according to which X-rays are irradiated. Furthermore, Figure 9 In this context, X-ray irradiation (D) refers to irradiation by X-rays emitted from X-ray tube 12 according to the irradiation control signal (C). Additionally, Figure 9 The determination function (E) in the text corresponds to the processing based on determination function 211, representing the determination of a period with less periodic movement based on the electrocardiogram waveform. Additionally, Figure 9 The ECG waveform acquisition function (F) shown corresponds to the processing based on the acquisition circuit 30, indicating the acquisition of ECG waveform information from the ECG machine 2.

[0170] For example, the X-ray diagnostic device 1 of the second embodiment acquires electrocardiogram waveform information at any time by acquiring circuit 30. Figure 9 The electrocardiogram waveform (B). That is, the acquisition circuit 30 acquires the signal at each moment by continuously acquiring the signal from the electrocardiograph 2, thereby obtaining the electrocardiogram waveform. Figure 9 The electrocardiogram waveform shown in (B) is as follows.

[0171] Furthermore, the X-ray diagnostic device 1 determines the period with less periodic movement based on the acquired electrocardiogram waveform (B). Here, as described above, the acquired electrocardiogram waveform (B) is a waveform that is delayed from the actual electrocardiogram waveform (A) of the subject. Therefore, the irradiation control function 213 can be used to... Figure 9 The time t2 shown shifts the pulses set for periods of less periodic movement determined by function 211 forward in time, thereby adjusting the way pulses are set for periods of less periodic movement within the actual subject. That is, irradiation control function 213 adjusts the pulse settings by shifting the pulses forward during periods of less periodic movement within the subject. Figure 9 The pulse P2 is moved forward by time t2 as shown in the X-ray irradiation (C), thus setting the pulse P2 for a period with less periodic movement in the actual subject.

[0172] Furthermore, similarly to the first embodiment, the irradiation control function 213 determines the irradiation control start time by performing pulse irradiation during a period when there is less periodic movement within the actual subject. That is, the irradiation control function 213 determines the irradiation control start time as a point in time t1 before the start time of the pulse (X-ray irradiation start time) set during a period when there is less periodic movement within the actual subject.

[0173] In addition, the delay time required from the acquisition of the electrocardiogram waveform by the electrocardiograph 2 to the transmission to the acquisition circuit 30 can be calculated based on the difference between the timestamp information given by the electrocardiograph 2 and the time information given by the acquisition circuit 30, or it can be input in advance via the input interface 22.

[0174] In the second embodiment described above, the processing circuit 21, the driving circuit 17, the system control circuit 18, and the acquisition circuit 30 can also be regarded as a single unit and understood as "processing circuit".

[0175] As described above, according to the second embodiment, the determination function 211 determines periods with less periodic movement based on electrocardiogram waveform information. Therefore, the X-ray diagnostic device 1 of the second embodiment can determine periods with less periodic movement using information typically obtained in endovascular interventional therapy.

[0176] Furthermore, according to the second embodiment, the acquisition circuit 30 acquires electrocardiogram (ECG) waveform information from the ECG machine 2. The irradiation control function 213 determines the irradiation start time based on the time from when the ECG machine 2 outputs a signal until the acquisition circuit 30 acquires the signal. Therefore, the X-ray diagnostic apparatus 1 of the second embodiment can determine a period with less periodic movement by taking into account the transmission time of the ECG waveform information, and can accurately determine the period.

[0177] (Third Implementation)

[0178] In the third embodiment, an example will be given of using fluoroscopic images and electrocardiogram waveform information to determine periods with minimal changes caused by heartbeat. Furthermore, the X-ray diagnostic apparatus 1 of the third embodiment differs from the X-ray diagnostic apparatus 1 of the second embodiment in the processing content of the determination function 211. The following description will focus on this aspect.

[0179] The determination function 211 of the third embodiment determines periods of less periodic motion based on multiple X-ray images and electrocardiogram (ECG) waveform information. Specifically, the determination function 211 uses the multiple fluoroscopic images described in the first embodiment and the ECG waveform information described in the second embodiment to determine periods of relatively less motion. That is, the X-ray diagnostic apparatus of the third embodiment has the same structure as the X-ray diagnostic apparatus 1 of the second embodiment, and acquires multiple fluoroscopic images and ECG waveform information. Furthermore, the determination function 211 uses the acquired multiple fluoroscopic images and ECG waveform information to determine periods of relatively less motion.

[0180] Here, the processing sequence of the X-ray diagnostic apparatus of the third embodiment will be explained first. Figure 10 This is a flowchart illustrating the processing sequence of the X-ray diagnostic apparatus 1 according to the third embodiment. Here, in Figure 10 The flowchart shown illustrates the process of obtaining ECG waveform information before performing input operations. Additionally, in... Figure 10 In the processing sequence shown, an example is given where the processing ends if no input operation is performed in the determination of whether the operator has performed an input operation. However, if no input operation is performed in the above determination, the processing flow can also be returned to the beginning.

[0181] Here, Figure 10 Step S301 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. Step S302 is implemented by reading from the storage circuit 24 and executing the program corresponding to the acquisition circuit 30. Step S303 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 211. Step S304 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. Step S305 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the programs corresponding to the illumination control function 213 and the image data generation function 214. Step S306 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the programs corresponding to the determination function 211 and the image processing function 215.

[0182] Furthermore, step S307 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 211. Furthermore, steps S308 to S309 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the determination function 212. Furthermore, steps S310 to S312 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the irradiation control function 213.

[0183] Furthermore, step S313 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the display control function 217, the image data generation function 214, and the image processing function 215. Furthermore, steps S314 and S317 are implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213. Furthermore, step S315 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the decision function 212. Furthermore, step S316 is implemented by the processing circuit 21 reading from the storage circuit 24 and executing the program corresponding to the illumination control function 213.

[0184] like Figure 10 As shown, in the X-ray diagnostic apparatus 1 of the third embodiment, the processing circuit 21 determines whether a high-dose X-ray irradiation mode termination operation has been performed (step S301). If a termination operation has been performed (step S301: Yes), the X-ray diagnostic apparatus 1 terminates processing. On the other hand, if a high-dose X-ray irradiation mode termination operation has not been performed (step S301: No), the acquisition circuit 30 acquires electrocardiogram (ECG) waveform information (step S302). Then, based on the ECG waveform information, the processing circuit 21 determines the next occurrence of a period of relatively small movement (step S303). Then, when the input interface 22 receives an input operation, the processing circuit 21 determines that the input operation is continuous (step S304). If the input operation is not continuous (step S304: No), the processing circuit 21 returns to step S301 and then determines whether a continuous input operation has been received.

[0185] On the other hand, while the input operation continues (step S304: Yes), similarly to the X-ray diagnostic apparatus 1 of the second embodiment, the processing circuit 21 generates a fluoroscopic image (step S305). Then, the processing circuit 21 calculates the amount of motion and the period of motion at each position for the fluoroscopic image (step S306).

[0186] Here, processing circuit 21 uses the period based on the electrocardiogram waveform and the period based on the fluoroscopic image determined in step S303 to estimate the next time the period of smaller periodic motion will occur (step S307). Specifically, processing circuit 21 estimates the next time the period of smaller periodic motion will occur based on the period based on the electrocardiogram waveform and the period based on the fluoroscopic image, and the delay time required from acquiring the electrocardiogram waveform through electrocardiograph 2 to transmitting it to acquisition circuit 30.

[0187] Here, if the timing of the periodic motion is not estimated (step S307: No), the conditions for the X-rays irradiated in step S312 (described later) will be changed from the value (preset) previously input through input interface 22 (step S315). Then, processing circuit 21 determines whether an input operation has been performed (step S316). If an input operation has been performed (step S315: Yes), it returns to step S305 and obtains the fluoroscopic image. On the other hand, if no input operation has been performed (step S315: No), processing circuit 21 ends the processing.

[0188] On the other hand, if the timing of the periodic motion being smaller can be estimated (step S307: Yes), the processing circuit 21 determines the pulse width of the X-ray irradiated in step S312 (step S308) based on the estimated period of the periodic motion being smaller and the X-ray conditions (preset) input in advance by the input interface 22. Furthermore, the processing circuit 21 determines the X-ray conditions other than the pulse width (step S308).

[0189] Next, the processing circuit 21 determines the irradiation control start time and the irradiation start time based on the delay time required from the output X-ray irradiation control signal to the actual X-ray irradiation (step S310). Then, the processing circuit 21 determines whether an input operation has been performed (step S311). If no input operation has been performed (step S311: No), the processing ends. On the other hand, if an input operation has been performed (step S311: Yes), the processing circuit 21 controls the imaging device 10 to perform high-dose X-ray irradiation along the irradiation start time (step S312).

[0190] Then, the processing circuit 21 uses the detection signal detected by the imaging device 10 irradiating a relatively high dose of X-rays to generate a relatively high dose X-ray image, and displays the generated high dose X-ray image on the display 23 (step S313).

[0191] Next, processing circuit 21, similarly to the X-ray diagnostic apparatus 1 of the first embodiment, determines whether an input requesting a change in conditions and re-perform high-dose X-ray irradiation has been accepted (step S314). Here, if processing circuit 21 accepts an input requesting a change in conditions for high-dose X-ray irradiation (step S314: Yes), it accepts the condition change input (step S317), returns to step S301, and performs processing. On the other hand, if no input requesting a change in conditions for high-dose X-ray irradiation has been accepted (step S314: No), processing circuit 21 terminates processing.

[0192] (Determining the time when periodic motion is less frequent)

[0193] As described above, in step S307, the determination function 211 of the third embodiment determines a period of relatively small motion based on multiple fluoroscopic images and electrocardiogram waveform information. Specifically, the determination function 211 compares a period of relatively small motion based on multiple fluoroscopic images with a period of relatively small motion based on electrocardiogram waveform information, and determines a period of relatively small motion based on the comparison result.

[0194] For example, function 211 compares the period based on multiple fluoroscopic images and the period based on electrocardiogram waveform information based on the time information collected from the fluoroscopic images and the time stamp information obtained from the electrocardiogram waveform, and determines the period with relatively small motion based on the comparison results.

[0195] Here, the determination function 211 prioritizes periods with relatively small motion based on the perspective image. That is, the determination function 211 prioritizes periods based on the actually calculated amount of motion. For example, the determination function 211 prioritizes periods with relatively small motion when the periods based on the perspective image and the periods based on the electrocardiogram waveform are determined to be different periods, when the periods based on the perspective image and the periods based on the electrocardiogram waveform are determined to be partially overlapping periods, and when the periods based on the perspective image are determined to be included within the periods based on the electrocardiogram waveform.

[0196] On the other hand, when the period based on the electrocardiogram waveform is determined to be a period included within the period based on the fluoroscopic image, the determination function 211 can determine the period based on the fluoroscopic image as a period with relatively small motion, or it can determine the period based on the electrocardiogram waveform as a period with relatively small motion.

[0197] Furthermore, if the determination of the period based on the fluoroscopic image fails, the determination function 211 can determine the period based on the electrocardiogram waveform as a period of relatively small movement. Here, the failure to determine the period based on the fluoroscopic image refers to situations such as when calculating the amount of movement by obtaining fluoroscopic images of three heartbeats, the moments when the amount of movement is below a threshold are scattered across the heartbeats.

[0198] The determination function 212 determines the pulse width and other X-ray conditions based on the relatively short period of motion determined by the determination function 211. Then, the irradiation control function 213 determines the irradiation start time by configuring the pulse with the pulse width determined by the determination function 212 during the relatively short period of motion. Furthermore, the irradiation control function 213 returns from the irradiation start time to the delay time required from the irradiation control signal outputting the X-rays until actual X-ray irradiation (e.g., ...). Figure 6 The time point t1 is determined as the start time of irradiation control.

[0199] As described above, according to the third embodiment, the determination function 211 determines the period with less periodic motion based on multiple fluoroscopic images and electrocardiogram waveform information. Therefore, the X-ray diagnostic apparatus 1 of the third embodiment can determine the period with less periodic motion through multiple means, and can continue processing without affecting subsequent processing even if one unit fails.

[0200] (Fourth Implementation)

[0201] In the first to third embodiments described above, the case of high-dose X-ray irradiation during periods of less periodic motion and the generation of high-dose X-ray images for display was explained. In the fourth embodiment, a further example of high-dose X-ray irradiation performed in conjunction with the imaging time is described. Figure 11 This is a block diagram illustrating an example of the structure of the X-ray diagnostic apparatus 1 according to the fourth embodiment. Furthermore, compared to the X-ray diagnostic apparatus 1 of the first embodiment, the X-ray diagnostic apparatus 1 of the fourth embodiment differs in the processing functions of the injector 3, the determination function 211, the irradiation control function 213, the image processing function 215, and the interpolation image generation function 216 connected to the X-ray diagnostic apparatus 1. These functions will be the focus of the following description.

[0202] Syringe 3 is a device for injecting contrast agent from a catheter inserted into the subject P. Here, the injection of contrast agent from syringe 3 is performed according to an injection instruction received via processing circuit 21. Specifically, syringe 3 performs contrast agent injection corresponding to contrast agent injection conditions received from processing circuit 21, including an injection start instruction, an injection stop instruction, and an injection rate. Furthermore, syringe 3 can also perform injection start and injection stop according to injection instructions directly input by the operator to syringe 3.

[0203] The determination function 211 of the fourth embodiment determines a period of reduced periodic movement in the subject after the contrast agent has been injected. Specifically, the determination function 211 determines a period of reduced periodic movement after the contrast agent has reached the area of ​​interest. For example, as described in the first to third embodiments, the determination function 211 determines the time when the period of reduced periodic movement occurs next based on at least one of multiple X-ray images and electrocardiogram waveform information, thereby determining the occurrence period of this period. That is, the determination function 211 determines the time of occurrence of the period of reduced periodic movement over time.

[0204] Furthermore, the determining function 211 determines the period of reduced periodic movement of the contrast agent after it reaches the region of interest, based on the contrast status in the region of interest of the subject. For example, the determining function 211 determines the time of occurrence of the period of reduced periodic movement after the contrast agent reaches the region of interest.

[0205] In addition, the determination function 211 can also determine the time when the period of less periodic motion will occur based on at least one of multiple X-ray images and electrocardiogram waveform information, and determine the period of less periodic motion that occurs after the contrast agent arrives in the region of interest based on the angiography status in the region of interest.

[0206] The irradiation control function 213 of the fourth embodiment determines the irradiation start time based on the injection status of the contrast agent into the blood vessel. Specifically, the irradiation control function 213 determines the irradiation start time for performing high-dose X-ray irradiation during a period when the periodic movement of the contrast agent after it reaches the area of ​​interest is relatively small. For example, similar to the first to third embodiments, the irradiation control function 213 determines the irradiation control start time and the irradiation start time by using various delay times.

[0207] The following describes an example of high-dose X-ray irradiation corresponding to the imaging status of the area of ​​interest. For example, the X-ray diagnostic apparatus 1 of the fourth embodiment performs high-dose X-ray irradiation linked to the imaging time by using the elapsed time from the start of the imaging.

[0208] In this case, function 211 determines a period with less periodic movement after a set time has elapsed since the start of contrast agent injection into the blood vessel. Here, the elapsed time is set based, for example, on the distance from the injection site of the contrast agent to the area of ​​interest and the injection rate of the contrast agent. That is, the elapsed time is set based on the time required for the contrast agent to reach the area of ​​interest.

[0209] The irradiation control function 213 determines the start time of irradiation during a period of less periodic motion after the contrast agent injection has elapsed, and performs high-dose X-ray irradiation. Thus, the X-ray diagnostic apparatus 1 of the fourth embodiment can collect high-dose X-ray images with minimal motion blur while the contrast agent has reached the region of interest. For example, by using the location where the stent is placed as the region of interest and performing the above processing, an X-ray image that allows observation of the adhesion between the vessel wall and the stent can be obtained.

[0210] In addition, as a high-dose X-ray irradiation corresponding to the imaging status of the area of ​​interest, for example, the X-ray diagnostic apparatus 1 of the fourth embodiment determines the imaging status of the area of ​​interest based on the imaging image, and performs high-dose X-ray irradiation linked to the imaging time by using the determination result.

[0211] For example, the determination function 211 determines the contrast status in the region of interest based on the contrast images collected after contrast agent injection, and determines a period with less periodic movement based on the determination result. As an example, the determination function 211 sequentially extracts the contrast agent region from multiple contrast images collected sequentially after contrast agent injection. Then, the determination function 211 determines the period with less periodic movement after the extracted contrast agent region exceeds a certain area. That is, the determination function 211 takes the moment when the contrast region exceeds a certain area as the moment when the contrast agent arrives in the region of interest, and determines the period with less periodic movement after the moment when the contrast agent arrives in the region of interest.

[0212] In addition, the determination function 211 can extract the contrast agent region in the contrast image by using methods such as methods based on the brightness value in the contrast image and deep learning.

[0213] The irradiation control function 213 determines the start time of irradiation during a period of less periodic motion, based on the area of ​​the contrast region in the contrast image, and performs high-dose X-ray irradiation. In this method, similar to the method using elapsed time, the X-ray diagnostic device 1 is able to collect high-dose X-ray images with less motion blur while the contrast agent has reached the region of interest.

[0214] Furthermore, if the set elapsed time and the time until the contrast agent region exceeds a certain area are shorter than the time required to determine a period with less periodic movement based on at least one of the multiple X-ray images and electrocardiogram waveform information, the irradiation control function 213, as described in the first to third embodiments, controls the irradiation to perform high-dose X-ray irradiation during the period with less periodic movement determined by the determination function 211.

[0215] As described above, the X-ray diagnostic apparatus 1 of the fourth embodiment can perform high-dose X-ray irradiation in conjunction with the imaging time of the contrast images. Here, for example, in the collection of contrast images based on DA (Digital Angiography) photography, it is also possible to simultaneously save contrast images before and after high-dose X-ray irradiation.

[0216] Therefore, the irradiation control function 213 of the fourth embodiment can be controlled in such a way that after a relatively high dose of X-ray irradiation is performed, X-ray images are sequentially produced by irradiating with a dose lower than that dose in the X-ray irradiation. That is, the irradiation control function 213 can be controlled in such a way that the collection of contrast images begins at a preset dose (hereinafter, sometimes referred to as normal dose irradiation), and after a high dose of X-ray irradiation is performed during a period with less periodic movement, the collection of contrast images based on the original dose continues. For example, the X-ray diagnostic apparatus 1 has the above-mentioned contrast image collection mode, and the collection of the above-mentioned contrast images is performed according to the mode switching via the input interface 22.

[0217] Display control function 217 can display a series of images collected and saved through the above-mentioned contrast imaging as dynamic images on display 23. Here, the quality of only one frame of the high-dose X-ray image collected by high-dose X-ray irradiation in the series of contrast imaging images is very good. Display control function 217 can also display only this high-quality dynamic image frame of the high-dose X-ray image as is, but by displaying the high-dose X-ray image with degraded image quality, the smoothness of dynamic image confirmation can be improved.

[0218] In this case, the image processing function 215 of the fourth embodiment generates a high-dose X-ray image that has undergone degradation processing on the high-dose X-ray image. Here, degradation processing is a process of correcting the difference in image quality in the X-ray detector 15, X-ray tube 12, and X-ray aperture 13 caused by different doses. By performing the above correction on the high-dose X-ray image, the image processing function 215 reduces the image quality of the high-dose X-ray image to the same level as the preceding and following frames.

[0219] Display control function 217 causes display 23 to display a dynamic image obtained by replacing the high-dose X-ray image in the series of contrast images with a degraded high-dose X-ray image generated by image processing function 215.

[0220] Furthermore, the aforementioned series of contrast images were collected after performing both normal dose irradiation and high dose X-ray irradiation. Therefore, since the switching between normal dose irradiation and high dose X-ray irradiation takes time, gaps may occur between frames collected by normal dose irradiation and frames collected by high dose X-ray irradiation, thus impairing the smoothness of dynamic image confirmation.

[0221] Therefore, the display control function 217 displays a dynamic image obtained by interpolating an interpolated image between frames collected by normal dose irradiation and frames collected by high dose X-ray irradiation. In this case, the interpolated image generation function 216 generates an interpolated image that corresponds to the time phase between the frames collected by normal dose irradiation and the frames collected by high dose X-ray irradiation.

[0222] Here, the interpolation image generation function 216 generates an interpolated image corresponding to the time phase between the last acquired contrast image from multiple contrast images and the time phase of the high-dose X-ray image obtained through high-dose X-ray irradiation. Additionally, the interpolation image generation function 216 generates an interpolated image corresponding to the time phase between the high-dose X-ray image and the time phase of a contrast image obtained after high-dose X-ray irradiation with a lower dose of X-rays than that irradiation. In other words, the interpolation image generation function 216 generates interpolated images corresponding to the time phases before and after high-dose X-ray irradiation.

[0223] For example, the interpolation image generation function 216 estimates the time-corresponding contrast state between the phase before high-dose X-ray irradiation and the phase after high-dose X-ray irradiation based on the contrast state of the last frame before high-dose X-ray irradiation and the contrast state in the high-dose X-ray image, and generates an interpolated image representing the estimated contrast state. Alternatively, for example, the interpolation image generation function 216 estimates the time-corresponding contrast state between the phase after high-dose X-ray irradiation and the phase after high-dose X-ray irradiation based on the contrast state of the first frame after high-dose X-ray irradiation and the contrast state in the high-dose X-ray image, and generates an interpolated image representing the estimated contrast state.

[0224] Display control function 217 enables the display of a motion image obtained by inserting an interpolated image generated by interpolation image generation function 216 into the aforementioned series of contrast images. Here, display control function 217 can also display information indicating that an interpolated image has been inserted into the motion image, and information indicating which frame is the interpolated image.

[0225] In the fourth embodiment described above, the processing circuit 21, the driving circuit 17, and the system control circuit 18 can also be regarded as a single unit and understood as "processing circuit".

[0226] As described above, according to the fourth embodiment, the irradiation control function 213 determines the irradiation start time based on the injection status of the contrast agent into the blood vessel. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can perform high-dose X-ray irradiation linked to the contrast agent injection time.

[0227] Furthermore, according to the fourth embodiment, the determination function 211 determines a period with less periodic movement after a set time has elapsed since the injection of contrast agent into the blood vessel. The irradiation control function 213 determines the irradiation start time based on the determined period with less periodic movement. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can easily perform high-dose X-ray irradiation linked to the contrast time.

[0228] Furthermore, according to the fourth embodiment, the irradiation control function 213 determines the injection status of the contrast agent into the blood vessel based on multiple X-ray images, and determines the irradiation start time based on the determination result. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can perform high-dose X-ray irradiation of the area of ​​interest under contrast imaging with high precision.

[0229] Furthermore, according to the fourth embodiment, the irradiation control function 213 is controlled in such a way that after a relatively high dose of X-ray irradiation is performed, X-ray images are sequentially created by irradiating X-rays with a lower dose than that in the X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can collect a series of X-ray images, including high-dose X-ray images and X-ray images before and after the high-dose X-ray images over time.

[0230] Furthermore, according to the fourth embodiment, the image processing function 215 performs degradation processing on high-dose X-ray images obtained by relatively high dose X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can improve the visual recognizability when high-dose X-ray images collected by high-dose X-ray irradiation are displayed continuously with X-ray images collected by normal dose irradiation.

[0231] Furthermore, according to the fourth embodiment, the interpolation image generation function 216 produces an interpolation image that corresponds to the phase between the phase of the last X-ray image obtained from multiple X-ray images and the phase of the high-dose X-ray image obtained by irradiation with a relatively high dose of X-rays. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can improve the visual recognizability of dynamic images even when the switching from normal dose irradiation to high-dose X-ray irradiation requires time.

[0232] Furthermore, according to the fourth embodiment, the interpolation image generation function 216 generates an interpolation image corresponding to the time phase between a high-dose X-ray image and an X-ray image obtained by irradiating X-rays with a lower dose than that dose after a relatively high dose of X-ray irradiation. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can improve the visual recognizability of dynamic images even when the switching from high-dose X-ray irradiation to normal-dose irradiation requires time.

[0233] Furthermore, according to the fourth embodiment, the display control function 217 causes the display unit to sequentially display a plurality of X-ray images, an interpolated image corresponding to the time phase between the last X-ray image obtained from the plurality of X-ray images and the time phase of the high-dose X-ray image, and the high-dose X-ray image. Therefore, the X-ray diagnostic apparatus 1 of the fourth embodiment can display dynamic images with improved visual recognition even when the switching from normal dose irradiation to high-dose X-ray irradiation requires time.

[0234] (Other implementation methods)

[0235] Thus, the first to fourth embodiments have been described, but in addition to the first to fourth embodiments described above, they can also be implemented in various different ways.

[0236] In the above-described embodiment, the method for calculating motion by the image processing function 215 is described as performing inter-frame difference and optical flow on multiple sequentially collected X-ray images, i.e., perspective images, to calculate motion. However, the embodiment is not limited to this. When a device with attached markers is depicted in the perspective image, the image processing function 215 may also detect marker pairs as feature points and calculate motion.

[0237] Furthermore, when the observed object is a device, the determination function 211, as a preprocessing step for calculating motion in the X-ray image, uses marker pairs to detect and segment the device, thereby enabling the calculation of motion only on the image region containing the segmented device. In other words, by calculating motion on the image region segmented by the image processing function 215, the determination function 211 reduces the motion calculation time. By observing the changes caused by the patient's heartbeat in real time via fluoroscopy, it determines in which phase of the next timeframe the period with relatively little motion occurs, thus reducing the motion calculation time and the time required to determine the period with relatively little motion. Moreover, by determining the period with relatively little motion in a short time, the time elapsed after fluoroscopy can be reduced, allowing for the determination of the relatively little period with higher accuracy.

[0238] In the above embodiments, the case where a conventional detector is used as the X-ray detector 15 has been described. However, the embodiments are not limited to this, and a detector capable of non-destructive and multiple readouts may also be used as the X-ray detector 15. Here, non-destructive and multiple readouts means that the signal value is read out multiple times during one pulse of X-ray irradiation. Hereinafter, the case of performing 5 readouts during one pulse of X-ray irradiation will be used as an example to describe a detector capable of non-destructive and multiple readouts.

[0239] In this case, when the period for reading the object is set to 1 frame, there are 5 frames in one pulse. The readout value of each frame is the signal value accumulated after the X-ray irradiation of the first pulse. Then, the readout value of the object frame is calculated based on the difference between the readout value and the previous frame.

[0240] Figure 12 This diagram illustrates an example of a detector capable of non-destructive and multiple readouts in other embodiments. Figure 12 The diagram illustrates a scenario where five readouts are performed within a single pulse of X-ray irradiation, resulting in five frames generated from that single pulse. For example, in... Figure 12 In this context, the signal value (1) of the first frame is readout value 1, which is the signal value accumulated from the start of illumination. Here, the detector, which can read out non-destructively and multiple times, does not eliminate the accumulated signal value even when the signal value of the first frame is read out, but instead accumulates and stores the signal value. That is, the readout value 2 read out next becomes the readout value obtained by further accumulating the signal from readout value 1.

[0241] Therefore, the signal value (2) of the second frame is calculated by subtracting the readout value 1 from the readout value 2. Similarly, the signal values ​​of the third to fifth frames are calculated by subtracting the immediately preceding readout value from the readout value. By using such a detector, motion can be calculated using only one pulse of illumination. As a result, for example, motion can be calculated even when perspective images are collected at a lower frame rate than usual. Furthermore, for example, motion can be calculated with higher accuracy even when perspective images are collected at a higher frame rate than usual, compared to calculating motion using perspective images.

[0242] The determination function 211 in other embodiments calculates the degree of periodic motion based on multiple X-ray images obtained from multiple readouts of a detector that performs multiple readouts during the exposure of one pulse of X-ray. Therefore, the X-ray diagnostic apparatus 1 in other embodiments can calculate the amount of motion per pulse, thereby improving the accuracy of determining periods with less periodic motion.

[0243] Furthermore, in the first embodiment described above, the case of generating an interpolated image that corresponds to the time phase of the last frame in a plurality of fluoroscopic images and the time phase of the frame (high-dose X-ray image) collected by high-dose X-ray irradiation was explained. However, the embodiment is not limited to this; for example, it is also possible to collect fluoroscopic frames again after collecting high-dose X-ray images. In this case, it is also possible to generate an interpolated image that corresponds to the time phase of the frame collected by high-dose X-ray irradiation and the time phase of the frame at the start of the next fluoroscopy. In this case, the display control function 217 can also control the display of the dynamic image obtained using each frame collected by fluoroscopy, the high-dose X-ray image, and the interpolated image.

[0244] In addition, the display control function 217 can also control the display of dynamic images obtained by using frames collected through fluoroscopy and high-dose X-ray images that have undergone degradation processing.

[0245] In the X-ray diagnostic apparatuses described in each embodiment, each processing function is stored in the storage circuit 24 in the form of a computer-executable program. The processing circuit 21 is a processor that reads and executes programs from the storage circuit 24 to implement the functions corresponding to each program. In other words, the processing circuit 21, which reads the state of each program, has the functions corresponding to the read programs. Furthermore, in the embodiments described above, each processing function is implemented by a single processing circuit 21, but the embodiments are not limited to this. For example, the processing circuit 21 may also be a circuit composed of multiple independent processors, and each processing function is implemented by each processor executing each program. In addition, the processing functions of the processing circuit 21 may also be appropriately distributed or combined in one or more processing circuits.

[0246] The term "processor" as used in the above description refers to circuits such as CPU (Central Processing Unit), GPU (Graphics Processing Unit), or Application Specific Integrated Circuit (ASIC), programmable logic device (e.g., Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA)). The processor performs its functions by reading and executing programs stored in memory 111.

[0247] Furthermore, in the embodiments described above, the storage circuit 24 stores programs corresponding to each processing function. However, it is also possible to configure multiple storage circuits 24 to be distributed, with the processing circuit 21 reading the corresponding program from an individual storage circuit 24. Alternatively, instead of storing the program in the storage circuit 24, the program can be directly programmed into the processor's circuitry. In this case, the processor implements the function by reading and executing the program programmed into the circuitry.

[0248] The constituent elements of the devices in the above-described embodiments are functional concepts and do not necessarily need to be physically configured as shown in the illustrations. That is, the specific methods of distributing or merging the devices are not limited to those shown in the illustrations, and they can be configured by functionally or physically distributing or merging all or part of them in any unit, depending on various loads, usage conditions, etc. Furthermore, all or any part of the processing functions performed in each device can be implemented by a CPU and the program parsed and executed by the CPU, or they can be implemented as hardware based on wiring logic.

[0249] Furthermore, the control method described in the above embodiments can be implemented by executing a pre-prepared control program using a computer such as a personal computer or workstation. This control program can be distributed via a network such as the Internet. Alternatively, the control program can be recorded on a computer-readable non-transitory recording medium such as a hard disk, floppy disk (FD), CD-ROM, MO, or DVD, and executed by a computer from the recording medium.

[0250] According to at least one embodiment described above, observation of the device can be made easier.

[0251] Several embodiments have been described, but these embodiments are given by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, modifications, and combinations of embodiments are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope or spirit of the invention, as well as in the scope of the invention as described in the claims and its equivalents.

Claims

1. An X-ray diagnostic device, comprising: The operation unit is responsible for input operations performed by the operator. The image generation unit sequentially generates X-ray images based on the X-rays that have irradiated and passed through the X-ray tube onto the subject. The determination unit determines, based on a plurality of X-ray images sequentially generated by the image generation unit, periods in the irradiated area of ​​the X-rays with less periodic motion; as well as The irradiation control unit controls the X-ray irradiation from the X-ray tube based on the input operation. Conditioned that the input operation is continuously performed, the unit determines the start time of irradiation of a high dose of X-rays, which is higher than the dose of X-rays when the plurality of X-ray images are generated, based on the period, and controls the high dose of X-rays to be irradiated at the determined start time.

2. The X-ray diagnostic apparatus according to claim 1, wherein, The determining unit determines the period with less periodic movement based on the multiple X-ray images and electrocardiogram waveform information.

3. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also includes a decision unit that determines the X-ray conditions based on the duration of the input operation and on periods with less periodic movement.

4. The X-ray diagnostic apparatus according to claim 3, wherein, The decision unit determines the pulse width based on the length of the period during which the periodic motion is less.

5. The X-ray diagnostic apparatus according to claim 3, wherein, The decision unit determines the focal size based on the length of the period with less periodic movement and the target dose.

6. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The determining unit calculates the degree of periodic motion at each location in the X-ray images based on the plurality of X-ray images.

7. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The determining unit calculates the degree of motion based on the magnitude of the periodic motion at each location in the plurality of X-ray images and the weighting coefficients corresponding to each location.

8. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The device includes a decision unit that determines the pulse width associated with the high-dose X-ray irradiation based on the duration of the input operation, the pulse width during X-ray irradiation when the plurality of X-ray images are generated, and the motion blur in the plurality of X-ray images.

9. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also features a detector that performs multiple readouts during the exposure to one pulse of X-rays. The determining unit calculates the degree of the periodic motion based on multiple X-ray images obtained from multiple readouts performed by the detector.

10. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The irradiation control unit determines the start time of irradiation based on the injection status of the contrast agent into the blood vessel.

11. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The determining unit determines a period of less periodic movement after a set time has elapsed since the start of contrast agent injection into the blood vessel. The irradiation control unit determines the start time of irradiation based on a period of less periodic movement determined by the determination unit.

12. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The irradiation control unit determines the injection status of the contrast agent based on multiple X-ray images collected during the injection of the contrast agent into the blood vessel, and determines the start time of the irradiation based on the determination result.

13. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The irradiation control unit controls the process to irradiate X-rays with a lower dose than that in the high-dose X-ray irradiation after the high-dose X-ray irradiation, and sequentially creates X-ray images.

14. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also includes an image processing unit that performs degradation processing on the high-dose X-ray images obtained by the high-dose X-ray irradiation.

15. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also includes an interpolation image generation unit that generates an interpolation image corresponding to the time phase between the last X-ray image obtained from the plurality of X-ray images and the time phase of the high-dose X-ray image obtained by the high-dose X-ray irradiation.

16. The X-ray diagnostic apparatus according to claim 15, wherein, The interpolation image generation unit generates an interpolation image corresponding to the phase between the high-dose X-ray image and the phase between the high-dose X-ray image and the X-ray image obtained by irradiating X-rays with a lower dose than that in the high-dose X-ray irradiation.

17. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The irradiation control unit determines the start time of the irradiation based on the time required from the output of the control signal instructing the high-dose X-ray irradiation to the commencement of the X-ray irradiation.

18. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also has an acquisition unit that acquires electrocardiogram waveform information from the electrocardiograph. The irradiation control unit determines the irradiation start time based on the time from when the signal is output by the electrocardiograph to when the signal is acquired by the acquisition unit.

19. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, Before accepting the input operation, the operation unit accepts the input operation to switch to the irradiation mode of performing the high-dose X-ray irradiation.

20. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, The operation unit accepts change input operations performed by the operator, which are related to at least one of the irradiation start time and X-ray conditions, based on the state of the high-dose X-ray image obtained through the high-dose X-ray irradiation. The irradiation control unit controls the execution of the high-dose X-ray irradiation after changing at least one of the irradiation start time and X-ray conditions, based on the change input operation.

21. The X-ray diagnostic apparatus according to claim 1 or 2, wherein, It also includes a display control unit that enables the display unit to display a high-dose X-ray image obtained by the high-dose X-ray irradiation.

22. The X-ray diagnostic apparatus according to claim 21, wherein, The display control unit causes the display unit to sequentially display a plurality of X-ray images, an interpolated image, and the high-dose X-ray image, wherein the interpolated image corresponds to the phase between the phase of the last X-ray image obtained with respect to the plurality of X-ray images and the phase of the high-dose X-ray image.

Images