X-ray diagnostic apparatus, X-ray control device, and X-ray control method

Abstract

To generate a transparent image of each of a plurality of regions of interest while properly reducing unnecessary exposure.SOLUTION: An X-ray diagnostic apparatus according to an embodiment includes an X-ray irradiation unit which emits an X-ray, an X-ray detection unit which detects the X-ray and a control unit. The control unit controls the dosage of the X-ray according to the movement of the irradiation region of the X-ray during fluoroscopy.SELECTED DRAWING: Figure 7

Description

Technical Field

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

Background Art

[0002] An X-ray diagnostic apparatus can be used to observe a fluoroscopic image of a region of interest of a subject. A user may desire to observe fluoroscopic images of a plurality of regions of interest, including the case of sequentially observing each of a pair of left and right organs.

[0003] When an X-ray diagnostic apparatus generates fluoroscopic images of, for example, two regions of interest, first, the X-ray irradiation region is positioned at the first region of interest to generate a fluoroscopic image of the first region of interest, and then the irradiation region is moved to the second region of interest to generate a fluoroscopic image of the second region of interest.

[0004] However, in this case, since X-ray irradiation for fluoroscopy continues even while the irradiation region is being moved from the first region of interest to the second region of interest, unnecessary radiation dose accumulates in the subject. On the other hand, if the X-ray dose is reduced while, for example, the support arm supporting the X-ray tube is operating in order to reduce this kind of unnecessary exposure, the X-ray dose is reduced just by finely adjusting the irradiation region of the X-rays in one region of interest, and the fluoroscopic image quality deteriorates, which is very inconvenient.

Prior Art Documents

Patent Documents

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Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One of the problems that the embodiments disclosed herein and in the drawings aim to solve is generating fluoroscopic images of multiple regions of interest while appropriately reducing unwanted radiation exposure. However, the problems that the embodiments disclosed herein and in the drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0007] The X-ray diagnostic apparatus according to this embodiment includes an X-ray irradiation unit that irradiates X-rays, an X-ray detection unit that detects X-rays, and a control unit. The control unit controls the X-ray dose according to the movement of the X-ray irradiation area during fluoroscopy. [Brief explanation of the drawing]

[0008] [Figure 1] A block diagram showing one example configuration of an X-ray diagnostic apparatus according to one embodiment. [Figure 2] A perspective view showing one example configuration of an X-ray movable diaphragm. [Figure 3] An explanatory diagram showing an example of the relationship between the aperture and the irradiation area. [Figure 4] This diagram illustrates an example of the positional relationship between the irradiation area, the X-ray detector, and the top plate when the irradiation area moves from the first region of interest to the second region of interest due to the movement of the aperture. [Figure 5] An explanatory diagram showing an example of the positional relationship between the irradiation area, the X-ray detector, and the top plate when the irradiation area is finely adjusted in the first region of interest. [Figure 6] An explanatory diagram showing an example of the positional relationship between the X-ray detector and the top plate when the irradiation area moves as the top plate moves. [Figure 7] A block diagram showing another configuration example of an X-ray diagnostic apparatus according to one embodiment. [Figure 8] A flowchart illustrating an example of the procedure for generating fluoroscopic images of multiple regions of interest while appropriately reducing unwanted radiation exposure using the processing circuit's processor. [Modes for carrying out the invention]

[0009] The embodiments of the X-ray diagnostic apparatus, X-ray control device, and X-ray control method will be described in detail below with reference to the drawings.

[0010] Figure 1 is a block diagram showing an example configuration of an X-ray diagnostic apparatus 1 according to one embodiment. Note that the X-ray diagnostic apparatus 1 according to this embodiment can be any apparatus capable of fluoroscopy, and includes, for example, an X-ray TV apparatus, a general radiography apparatus, or an X-ray angiography apparatus. Figure 1 shows an example where an X-ray TV apparatus is used as the X-ray diagnostic apparatus 1.

[0011] As shown in Figure 1, the X-ray diagnostic apparatus 1 includes an imaging apparatus 2 and a console 3. The imaging apparatus 2 includes an X-ray irradiator 10 which contains an X-ray tube 11 and a housing 12 that houses an X-ray movable diaphragm 20, an X-ray detector 13, a support member 14, a support column drive mechanism 15, a tabletop 16, and a patient bed 17. In this embodiment, the short side of the tabletop 16 is defined as the x-axis, the normal direction of the tabletop 16 as the y-axis, and the long side of the tabletop 16 as the z-axis (see Figure 1).

[0012] The X-ray tube 11 of the X-ray irradiator 10 generates X-rays when a voltage is applied by the X-ray high-voltage device 11x. The X-ray tube 11 is composed of a vacuum tube that irradiates thermionic electrons from the cathode (filament) to the anode (target) when a high voltage is applied from the X-ray high-voltage device 11x.

[0013] The X-ray high-voltage device 11x is controlled by the processing circuit 35 of the console 3 to control the dose of X-rays emitted by the X-ray tube 11 by controlling the tube voltage value kV, tube current value mA, irradiation time per frame, etc. The X-ray high-voltage device 11x includes, for example, a high-voltage generator, a tube voltage detection circuit, a tube voltage control circuit, a tube current detection circuit, a filament power supply, a filament current detection circuit, a filament power supply control circuit, a grid power supply, a grid voltage detection circuit, and a grid power supply control circuit.

[0014] The housing 12 is a housing made of metal, and in addition to housing at least the X-ray movable aperture 20, it may also house a region of interest filter (ROI filter), a compensating filter, and a quality filter. The X-ray tube 11 and the housing 12 are supported at one end of the support member 14 as shown in FIG. 1.

[0015] FIG. 2 is a perspective view showing a configuration example of the X-ray movable aperture 20.

[0016] The X-ray movable aperture 20 has an aperture 25 for restricting (narrowing) the irradiation region of the X-ray. While allowing the X-ray to pass through the aperture 25, it restricts the passage of the X-ray in regions other than the aperture 25. The X-ray movable aperture 20 is constituted by, for example, aperture blades including a plurality of blade elements. The X-ray movable aperture 20 is an example of an X-ray aperture.

[0017] The aperture blades have, for example, four blade elements 21, 22, 23, and 24 as shown in FIG. 2. The blade elements 21 - 24 are each constituted by a flat lead plate or the like to shield the X-ray. The region surrounded by the blade elements 21 - 24 forms an aperture 25 through which the X-ray passes (see FIG. 2).

[0018] By these blade elements 21 - 24 moving parallel to each other with respect to the X-ray tube 11 independently, while the support member 14 remains stationary and the positions of the X-ray tube 11 and the X-ray detector 13 are fixed, the position of the aperture 25 can be moved parallel to the surface of the top plate 16, and the size of the aperture 25 can be changed. For this reason, even while the positions of the X-ray tube 11 and the X-ray detector 13 are fixed, it is possible to change the position and size of the irradiation region corresponding to the aperture 25. Note that the number of blade elements of the aperture blades is not limited to the four shown in FIG. 2, and for example, a multi-leaf collimator may be used as the aperture blades.

[0019] The X-ray detector 13 is supported by the bed 17 so as to be disposed opposite to the X-ray tube 11 and the X-ray movable diaphragm 20 with the subject placed on the top plate 16 of the bed 17 interposed therebetween. The X-ray detector 13 is constituted by a flat panel detector (FPD), detects X-rays transmitted through the subject and irradiated onto the X-ray detector 13, and outputs image data of an X-ray fluoroscopic image or an X-ray radiographic image based on the detected X-rays, and supplies it to the console 3. Note that the X-ray detector 13 may include an image intensifier, a TV camera, or the like.

[0020] The support member 14 is a column that supports the X-ray irradiator 10. The column drive mechanism 15 includes a drive mechanism for integrally tilting the support member 14 and the bed 17 about an axis parallel to the x-axis with the column drive mechanism 15 as the center. Further, the column drive mechanism 15 may include a drive mechanism for tilting the support member 14 about an axis parallel to the x-axis with the column drive mechanism 15 as the center. In this case, the X-rays irradiated from the X-ray tube 11 can be obliquely incident on the X-ray detector 13.

[0021] A top plate 16 is provided on the upper portion of the bed 17, and the subject is placed on the top plate 16. Further, a shoulder rest, a footrest, a side hand grip, or the like for supporting the subject may be attached to the bed 17. The top plate 16 is moved along the longitudinal direction and the lateral direction of the top plate 16 with respect to the bed 17 by a top plate drive mechanism (not shown). The top plate drive mechanism has a motor as a drive source for moving the top plate 16, and electronic components for controlling this motor.

[0022] The console 3 is constituted by, for example, a general personal computer or a workstation, and has an input interface 31, a display 32, a memory circuit 33, a network connection circuit 34, and a processing circuit 35. Note that the console 3 may not be provided independently, and for example, a part of the components 31 - 35 of the console 3 may be dispersedly provided on the bed 17 or the like.

[0023] The input interface 31 is comprised of common input devices such as a trackball, switch buttons, mouse, keyboard, or numeric keypad, and outputs an operation input signal corresponding to user operation to the processing circuit 35. For example, the user can set imaging conditions via the input interface 31. The input interface 31 may also include an exposure switch to control the on / off state of exposure.

[0024] The display 32 is composed of a common display output device such as a liquid crystal display or an OLED (Organic Light Emitting Diode) display, and displays various information such as fluoroscopic images generated by the processing circuit 35 based on X-ray imaging.

[0025] The memory circuit 33 has a configuration that includes a processor-readable recording medium, such as a magnetic or optical recording medium or a semiconductor memory. Some or all of the program and data in the recording medium may be configured to be downloaded via communication over an electronic network.

[0026] The network connection circuit 34 is composed of, for example, a network card having a predetermined printed circuit board, and implements various information and communication protocols according to the network configuration. The network connection circuit 34 connects the X-ray diagnostic device 1 to other equipment according to these various protocols. This connection can be an electrical connection via an electronic network, etc. Here, an electronic network refers to all information and communication networks that utilize telecommunications technology, and includes wireless / wired hospital backbone LANs (Local Area Networks) and the Internet, as well as telephone communication lines, optical fiber communication networks, cable communication networks, and satellite communication networks.

[0027] The processing circuit 35 implements the function of overall control of the X-ray diagnostic apparatus 1. Furthermore, the processing circuit 35 is a processor that reads and executes programs stored in the memory circuit 33, thereby performing processing to generate fluoroscopic images of multiple regions of interest while appropriately reducing unnecessary radiation exposure.

[0028] As shown in Figure 1, the processor of the processing circuit 35 has an imaging control function 351, a motion detection function 352, and an image generation function 353. Each of these functions is stored in the memory circuit 33 in the form of a program. The imaging control function 351 and the motion detection function 352 constitute the X-ray control device.

[0029] Furthermore, some or all of the functions of the processing circuit 35 of the console 3 may be implemented by a processing circuit of the imaging device 2 (not shown).

[0030] The imaging control function 351 controls the X-ray dose according to the movement of the X-ray irradiation area during fluoroscopy. Specifically, the imaging control function 351 controls the X-ray irradiator 10 to reduce the X-ray dose while the irradiation area is moving. The imaging control function 351 is an example of a control unit.

[0031] For example, the imaging control function 351 may reduce the X-ray dose by controlling the X-ray high-voltage device 11x to control at least one of the tube voltage value kV and the product of the tube current value mA and the irradiation time mAs while the irradiation area is moving. Alternatively, the imaging control function 351 may reduce the X-ray dose by switching the compensation filter or beam quality filter housed in the housing 12. Furthermore, the imaging control function 351 may reduce the X-ray dose to the subject by switching from continuous imaging to pulsed fluoroscopy, which irradiates X-rays in pulses several times per second.

[0032] The motion detection function 352 detects the movement of the X-ray irradiation area. Here, the movement of the irradiation area includes stationary, fine-tuning, and movement. During fluoroscopic observation of a predetermined region of interest, the irradiation area is stationary or slightly moved to fine-tune its position. On the other hand, when changing the object of observation from the current region of interest to another region of interest, the irradiation area moves significantly between regions of interest.

[0033] For example, when sequentially observing fluoroscopic images of multiple regions of interest, the illumination area will be moved between each region of interest. These types of multiple regions of interest include pairs of organs such as the left and right kidneys, or multiple regions of interest set along the esophagus.

[0034] For example, if fluoroscopy is performed on the left kidney and then on the right kidney, the irradiation area moves from the left kidney to the right kidney. However, a high-resolution fluoroscopic image is not required during this transition.

[0035] Therefore, the movement detection function 352 may detect whether the irradiation area is stationary, undergoing fine adjustment, or moving, for example, based on the movement speed of the irradiation area. For example, the movement detection function 352 detects that the irradiation area is moving if the movement speed of the irradiation area is above a threshold, and detects that the irradiation area is stationary or undergoing fine adjustment if it is below the threshold. Alternatively, the movement detection function 352 may use other speed thresholds smaller than the aforementioned threshold to distinguish between stationary and fine adjustment.

[0036] Furthermore, the movement detection function 352 may also detect the movement of the X-ray irradiation area by using the time during which a movement speed above a threshold is maintained. In this case, the movement detection function 352 detects that the irradiation area is moving when the movement speed of the irradiation area is above a threshold for a predetermined time or longer. By using the time during which a movement speed above a threshold is maintained, for example, even if the movement speed momentarily exceeds the threshold when the irradiation area is moved for fine adjustment, it is possible to appropriately detect that fine adjustment is currently underway by indicating that the speed is not maintained for a predetermined time or longer.

[0037] The imaging control function 351 controls the X-ray dose based on the detection results of the movement detection function 352. When the irradiation area is stationary or undergoing fine adjustment, the imaging control function 351 maintains the X-ray dose to maintain the image quality of the currently fluoroscopic image. On the other hand, when the irradiation area is moving, the imaging control function 351 determines that movement should take precedence over image quality and controls the X-ray irradiator 10 to reduce the X-ray dose. Here, reducing and lowering the X-ray dose includes stopping the X-rays.

[0038] The image generation function 353 generates a fluoroscopic image based on the output of the X-ray detector 13 and displays it on the display 32. The image generation function 353 is an example of an image generation unit.

[0039] Furthermore, while the irradiation area is moving, the imaging control function 351 reduces the X-ray dose, which worsens the visibility of the fluoroscopic image. Therefore, while the imaging control function 351 is reducing the X-ray dose during the movement of the irradiation area, it may change the image processing settings of the image generation function 353 to improve the visibility of the fluoroscopic image. For example, while the image generation function 353 is reducing the X-ray dose during the movement of the irradiation area, it may improve the visibility of the fluoroscopic image by weakening or turning off image processing that is sensitive to motion blur, such as a recursive filter.

[0040] Furthermore, if the X-ray diagnostic device 1 has an automatic brightness control (ABC) function, the imaging control function 351 should suppress automatic dose control based on ABC by weakening or turning off ABC while the X-ray dose is being reduced during movement of the irradiation area. The automatic brightness control function is a function that automatically controls the X-ray conditions by feedback control so that the difference between the target value and the current brightness value disappears, so that the brightness value, which is an example of an index value related to the image quality of fluoroscopic images, becomes optimal (target value). While ABC can stabilize the image quality of the fluoroscopic image during fluoroscopy of the region of interest, it is advisable to deliberately turn off and interrupt ABC while the X-ray dose is being reduced during movement of the irradiation area, or to perform ABC with a weaker brightness tracking setting than during fluoroscopy of the irradiation area, in order to prevent unintended dose increases.

[0041] Next, the method for detecting the movement of the X-ray irradiation area using the movement detection function 352 will be explained with reference to Figure 3-6.

[0042] Figure 3 is an explanatory diagram showing an example of the relationship between the aperture 25 and the irradiation area 41. Figure 3 shows an example where the direction of movement of the irradiation area 41 is in the positive x-axis direction.

[0043] Figure 4 is an explanatory diagram showing an example of the positional relationship between the irradiation area 41, the X-ray detector 13, and the top plate 16 when the irradiation area 41 moves from the first region of interest 51 to the second region of interest 52 as the aperture 25 moves.

[0044] As shown in Figure 3, the X-ray beam 40 can be moved by moving the aperture 25 of the movable X-ray diaphragm 20. Therefore, even if the X-ray tube 11, X-ray detector 13, and top plate 16 remain stationary, the irradiation area on the top plate 16 can be moved by moving the aperture 25 (see Figure 4). In this case, the irradiation area 41 on the X-ray detector 13 can be moved, for example, from the right end 13r to the left end 13l of the X-ray detector 13 by moving the aperture 25 in the positive x-axis direction (see Figure 3).

[0045] Therefore, the movement detection function 352 may detect the movement of the irradiation area 41 based on the movement speed of the aperture 25 of the X-ray movable diaphragm 20. For example, the movement detection function 352 detects that the irradiation area 41 is moving when the movement speed of the aperture 25 is above a threshold and a predetermined time has elapsed. The imaging control function 351 receives this detection result and controls the X-ray irradiator 10 to reduce the X-ray dose. Alternatively, if the entire X-ray irradiator 10 is moved, the movement of the irradiation area 41 may be detected based on the movement speed of the X-ray irradiator 10.

[0046] Furthermore, in the example shown in Figure 4, the irradiation area 41 on the X-ray detector 13 moves in accordance with the movement of the aperture 25. Therefore, the movement detection function 352 may detect the movement of the irradiation area 41 based on changes in the output signals of each element of the X-ray detector 13.

[0047] Figure 5 is an explanatory diagram showing an example of the positional relationship between the irradiation area 41, the X-ray detector 13, and the top plate 16 when the irradiation area 41 is finely adjusted in the first region of interest 51.

[0048] As shown in Figure 5, even when the irradiation area 41 moves, this movement may not be intended to change the region of interest but rather to fine-tune the irradiation area. In this case, the movement detection function 352 can detect that the irradiation area 41 is being fine-tuned because the movement speed of the aperture 25 is lower than a threshold, or the time during which the movement speed is above the threshold ends in less than a predetermined time. The imaging control function 351 receives this detection result and controls the X-ray irradiator 10 to maintain the X-ray dose.

[0049] Figure 6 is an explanatory diagram showing an example of the positional relationship between the X-ray detector 13 and the top plate 16 when the irradiation area moves as the top plate 16 moves.

[0050] Even with the X-ray tube 11, aperture 25, and X-ray detector 13 stationary, the irradiation area on the X-ray top plate 16 can be moved by moving the top plate 16 (see Figure 6).

[0051] Therefore, the movement detection function 352 may detect the movement of the irradiation area 41 based on the movement speed of the top plate 16. For example, the movement detection function 352 detects that the irradiation area 41 is moving when the movement speed of the top plate 16 is above a threshold and a predetermined time has elapsed. The imaging control function 351 receives this detection result and controls the X-ray irradiator 10 to reduce the X-ray dose.

[0052] Furthermore, the movement detection function 352 may detect the movement of both the aperture 25 of the X-ray movable diaphragm 20 and the top plate 16, and control the X-ray dose according to the relative movement of the aperture 25 and the top plate 16. In this case, the movement detection function 352 may, for example, detect that the irradiation area 41 is moving when the relative movement speed of the aperture 25 and the top plate 16 exceeds a threshold and a predetermined time has elapsed.

[0053] Figure 7 is a block diagram showing another configuration example of the X-ray diagnostic apparatus 1 according to one embodiment. Figure 7 shows an example in which an imaging apparatus 2 having a C-arm as a support member 14 is used.

[0054] The C-arm, which serves as a support member 14 for the imaging device 2 shown in Figure 7, holds the X-ray irradiator 10 and the X-ray detector 13. The X-ray irradiator 10 and the X-ray detector 13 are positioned opposite each other, with the subject in between, by the C-arm.

[0055] When using such an imaging device 2, the movement detection function 352 may control the X-ray dose according to the movement of the C-arm. In this case, the movement detection function 352 may, for example, detect that the irradiation area 41 is moving when the movement speed of the C-arm exceeds a threshold and a predetermined time has elapsed.

[0056] Furthermore, when fluoroscopying multiple regions of interest, the same X-ray dose may be used for each region. In this case, the imaging control function 351 should store the irradiation conditions, such as the tube voltage and filter type that provide the current X-ray dose, in the memory circuit 33. In this case as well, the imaging control function 351 reduces the X-ray dose when the irradiation area begins to move to the next region of interest. Then, when the imaging control function 351 detects that the irradiation area is stationary or undergoing fine adjustment, it determines that the next region of interest has been reached and finishes the X-ray dose reduction process by returning the X-ray dose to the dose before the movement using the irradiation conditions read from the memory circuit 33. In this way, by reducing the X-ray dose while moving between regions of interest, unnecessary exposure of the subject can be reduced, and fluoroscopy can be easily performed with the same X-ray dose between the region of interest before and after the movement.

[0057] Furthermore, if the X-ray diagnostic device 1 has an auto-positioning function, the imaging control function 351 reduces the X-ray dose while the irradiation area moves to the region of interest set using the auto-positioning function. In this case as well, it is preferable to store the irradiation conditions before the movement in the memory circuit 33 so that the X-ray dose can be returned to the dose before the movement after the irradiation area has moved. The auto-positioning function is a function that automatically moves the irradiation area to the imaging position according to the examination, and is executed by the processing circuit 35 after receiving a start instruction from the user to the input interface 31 based on the information of the area to be imaged included in the examination information.

[0058] Figure 8 is a flowchart illustrating an example of the procedure for generating fluoroscopic images of multiple regions of interest while appropriately reducing unwanted radiation exposure using the processor in the processing circuit 35. In Figure 8, the numbers attached to S indicate each step in the flowchart. This procedure starts when the first region of interest is ready for fluoroscopy.

[0059] First, in step S1, the imaging control function 351 starts fluoroscopy of the region of interest, and the image generation function 353 generates a fluoroscopic image and displays it on the display 32. Next, in step S2, the imaging control function 351 stores in the memory circuit 33 the irradiation conditions, such as the tube voltage and filter type that provide the dose of X-rays currently being fluoroscopyed.

[0060] Next, in step S3, the movement detection function 352 determines whether the X-ray irradiation area has started to move. If the irradiation area is stationary or undergoing fine adjustment, the process returns to step S8. On the other hand, if the irradiation area has started to move, the process proceeds to step S4.

[0061] Next, in step S4, the imaging control function 351 controls the X-ray irradiator 10 to reduce the X-ray dose. Specifically, the imaging control function 351 may control the X-ray high-voltage device 11x to control at least one of the tube voltage value kV and the product of the tube current value mA and irradiation time mAs, or it may switch the compensation filter or beam quality filter housed in the housing 12, or it may switch from continuous imaging to pulsed fluoroscopy, or a combination of these.

[0062] Next, in step S5, the movement detection function 352 determines whether the movement of the irradiation area has finished. If the irradiation area is stationary or undergoing fine adjustment, it is determined that the movement of the irradiation area has finished. If the movement of the irradiation area has not finished and is still moving, step S5 is repeated. On the other hand, if the movement of the irradiation area has finished, the process proceeds to step S6.

[0063] Next, in step S6, the imaging control function 351 reads out the irradiation conditions stored in the memory circuit 33 and uses them to return the X-ray dose to the dose before movement.

[0064] Next, in step S7, the imaging control function 351 starts fluoroscopy of the region of interest, and the image generation function 353 generates a fluoroscopic image and displays it on the display 32.

[0065] Next, in step S8, the imaging control function 351 determines whether or not to terminate the series of fluoroscopy. If the fluoroscopy should be terminated based on user instructions via the input interface 31, the series of procedures ends. On the other hand, if the fluoroscopy should be continued, the process returns to step S2.

[0066] By following the above procedure, it is possible to generate fluoroscopic images of multiple regions of interest while appropriately reducing unnecessary radiation exposure.

[0067] The X-ray control device and X-ray diagnostic apparatus 1 including the X-ray control device, which are configured with the imaging control function 351 and the movement detection function 352 according to this embodiment, can control the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy. At this time, it is possible to determine whether the irradiation area is moving significantly or whether its position is being finely adjusted. Therefore, when the irradiation area is moving significantly, the X-ray dose can be reduced to reduce unnecessary exposure of the subject, and when the position of the X-ray irradiation area in a single region of interest is being finely adjusted, the X-ray dose can be maintained to maintain the image quality of the fluoroscopic image. Thus, the user can reduce the exposure dose when the irradiation area is moving significantly without paying attention to the X-ray dose, and can observe a fluoroscopic image with suitable image quality while the position of the irradiation area is being finely adjusted.

[0068] Furthermore, when fluoroscopying multiple regions of interest with the same X-ray dose, such as when fluoroscopying each of the left and right kidneys, the imaging control function 351 stores the current irradiation conditions in the memory circuit 33. This allows for easy fluoroscopy with the same X-ray dose across multiple regions of interest while reducing unnecessary exposure to the subject by decreasing the X-ray dose during movement between regions of interest.

[0069] According to at least one embodiment described above, it is possible to generate fluoroscopic images of multiple regions of interest while appropriately reducing unwanted radiation exposure.

[0070] In the above embodiments, the term "processor" refers to circuits such as a dedicated or general-purpose CPU (Central Processing Unit), GPU (Graphics Processing Unit), or Application Specific Integrated Circuit (ASIC), or programmable logic device (e.g., Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA)). When the processor is a CPU, for example, it realizes various functions by reading and executing a program stored in a memory circuit. When the processor is an ASIC, for example, instead of storing a program in a memory circuit, the functions corresponding to the program are directly incorporated as logic circuits within the processor's circuitry. In this case, the processor realizes various functions through hardware processing that reads and executes the program incorporated within the circuitry. Alternatively, the processor can also realize various functions by combining software processing and hardware processing.

[0071] Furthermore, although the above embodiment shows an example where a single processor in the processing circuit implements each function, a processing circuit may be configured by combining multiple independent processors, with each processor implementing each function. Also, when multiple processors are provided, the memory circuit for storing programs may be provided individually for each processor, or a single memory circuit may store programs corresponding to the functions of all processors together.

[0072] While several embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be implemented in a variety of other forms, 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 and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0073] 1. X-ray diagnostic equipment 2. Imaging device 3 Console 10 X-ray irradiator 11 X-ray tube 13 X-ray detector 14 Support Member 16 Top plate 20 X-ray movable diaphragm 25 Aperture 33 Memory circuit 35 Processing Circuit 41 Irradiation area 51. First area of ​​interest 52 Second area of ​​interest 351 Shooting control function 352 Motion detection function 353 Image generation function

Claims

1. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, When the movement speed of the X-ray diaphragm aperture exceeds a threshold, the X-ray irradiation unit is controlled to reduce the X-ray dose. X-ray diagnostic equipment.

2. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, When the movement speed of the top plate on which the subject is placed exceeds a threshold, the X-ray irradiation unit is controlled to reduce the X-ray dose. X-ray diagnostic equipment.

3. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, The X-ray dose is controlled according to the relative movement speed between the aperture of the X-ray diaphragm and the table on which the subject is placed. X-ray diagnostic equipment.

4. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, If the movement speed of at least one of the X-ray aperture, the top plate on which the subject is placed, the support member that supports the X-ray irradiation unit, and the X-ray irradiation unit is above a threshold for a predetermined period of time, the X-ray irradiation unit is controlled to reduce the X-ray dose. X-ray diagnostic equipment.

5. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, When changing the fluoroscopic target from the first region of interest currently being fluoroscopyed to the second region of interest using the auto-positioning function, the X-ray irradiation unit is controlled to reduce the X-ray dose while the irradiation area moves from the first region of interest to the second region of interest. X-ray diagnostic equipment.

6. An X-ray irradiation unit that irradiates with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that controls the X-ray dose in accordance with the movement of the X-ray irradiation area during fluoroscopy, Equipped with, The control unit, While maintaining the X-ray dose in accordance with the movement of the irradiation area, a predetermined automatic brightness control is performed. Conversely, while decreasing the X-ray dose in accordance with the movement of the irradiation area, the predetermined automatic brightness control is interrupted or automatic control is performed with a brightness tracking setting weaker than the predetermined automatic brightness control. X-ray diagnostic equipment.

7. The control unit, If the aforementioned movement speed exceeds a threshold and a predetermined time has elapsed, the system determines that the irradiation area is moving and controls the X-ray irradiation unit to reduce the X-ray dose; otherwise, the system determines that the position of the irradiation area is being finely adjusted and controls the X-ray irradiation unit to maintain the X-ray dose. The X-ray diagnostic apparatus according to any one of claims 1 to 4.

8. The control unit, The X-ray irradiation conditions before reducing the X-ray dose in response to the aforementioned movement are stored in a memory circuit, and after reducing the X-ray dose in response to the aforementioned movement, when the reduction in the X-ray dose in response to the aforementioned movement is complete, the X-ray irradiation unit is controlled to return to the dose before the reduction by using the irradiation conditions read from the memory circuit. The X-ray diagnostic apparatus according to any one of claims 1 to 4 and 7.

9. An image generation unit that generates a fluoroscopic image based on the output of the X-ray detection unit. Furthermore, The control unit, While the X-ray dose is being reduced in accordance with the aforementioned movement, the image processing settings of the image generation unit are changed to improve the visibility of the fluoroscopic image during the movement of the irradiation area and the reduction of the dose. The X-ray diagnostic apparatus according to any one of claims 1 to 5, 7, and 8.

10. A control unit that controls the X-ray dose according to the movement of the X-ray irradiation area during fluoroscopy. Equipped with, The control unit, The X-ray dose is controlled according to the relative movement speed between the aperture of the X-ray diaphragm and the table on which the subject is placed. X-ray control device.

11. A step of detecting the movement of the X-ray irradiation area during fluoroscopy, A step of controlling the X-ray dose in accordance with the aforementioned movement, A step of controlling the X-ray dose according to the relative movement speed between the aperture of the X-ray diaphragm and the table on which the subject is placed, An X-ray control method having the following characteristics.

Images