X-ray fluoroscopic imaging device and image processing method

Abstract

The invention provides an X-ray fluoroscopic imaging apparatus and an image processing method. The present invention addresses the problem of making it possible to reduce the amount of X-ray radiation by increasing the ratio of an interpolated image when the accuracy or real-time performance of a perspective image is not required, and to maintain a display frame rate equivalent to when the accuracy or real-time performance of the perspective image is required. The X-ray fluoroscopic imaging device can change the irradiation rate according to the operation of an operator. The X-ray fluoroscopic imaging device displays a fluoroscopic image generated at an irradiation rate on an image display device when the irradiation rate is equal to or greater than a reference rate, and generates an interpolated frame so that the display rate becomes equal to the reference rate when the irradiation rate is lower than the reference rate. And displaying the perspective image generated at the irradiation rate and the interpolated frame on an image display device.

Description

Technical Field

[0001] The present invention relates to an X-ray fluoroscopic imaging device capable of generating fluoroscopic images and an image processing method. Background Art

[0002] When a surgeon performs surgery on a patient while performing X-ray fluoroscopy, both the patient and the surgeon are exposed to radiation. Therefore, technologies for reducing radiation exposure have been proposed. For example, Patent Document 1 discloses a method for reducing radiation exposure while maintaining the display frame rate of fluoroscopic images during pulsed fluoroscopy. The method involves lengthening the X-ray irradiation interval and interpolating between images using interpolated images generated from intermediate images of preceding and succeeding frames.

[0003] Patent Document 1: International Publication No. 2016 / 021240

[0004] Reducing the number of X-ray image acquisitions and instead increasing the use of interpolated images can be expected to further reduce radiation exposure. However, increasing the proportion of interpolated images reduces image reliability, and increasing the proportion of interpolated images increases time delay, which can compromise real-time performance. Furthermore, changing the frame rate during fluoroscopy can cause discomfort to the viewer when later viewing the recorded fluoroscopy images. Summary of the Invention

[0005] The purpose of the present invention is to reduce the radiation dose based on X-rays by increasing the proportion of interpolated images when the accuracy or real-time performance of fluoroscopic images is not required, and to maintain the same display frame rate as when the accuracy or real-time performance of fluoroscopic images is required.

[0006] To achieve the above-mentioned objectives, according to one embodiment of the present invention, an X-ray fluoroscopy imaging apparatus is provided, comprising: an irradiation device including an X-ray tube for irradiating a subject with X-rays and an X-ray detector for detecting X-rays transmitted through the subject; a system control device for controlling the irradiation rate of X-ray pulses of the irradiation device; an image processing control device for generating fluoroscopic images at a rate corresponding to the irradiation rate based on output from the X-ray detector; and an image processing device for displaying the fluoroscopic images generated by the image processing control device on an image display device. The system control device is capable of changing the irradiation rate in response to an operator's operation. While displaying the fluoroscopic images on the image display device, if the irradiation rate is changed to a value lower than the irradiation rate at the start of fluoroscopy, the image processing device generates interpolated frames so that the frame rate of the image displayed on the image display device becomes equal to the irradiation rate at the start of fluoroscopy, and displays the fluoroscopic images and the interpolated frames on the image display device.

[0007] Effects of the Invention

[0008] According to one embodiment of the present invention, when the accuracy or real-time performance of fluoroscopic images is not required, the radiation dose based on X-rays can be reduced by increasing the ratio of interpolated images, and the display frame rate can be maintained equivalent to that when the accuracy or real-time performance of fluoroscopic images is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a block diagram showing the overall configuration of the X-ray fluoroscopy apparatus according to the first embodiment of the present invention.

[0010] Figure 2 This is a diagram showing the display of the irradiance operator according to the first embodiment.

[0011] Figure 3 This is a diagram showing the display of the interpolation mode operator in the first embodiment.

[0012] Figure 4 This is a diagram for explaining the operation of the interpolation mode (constant display rate) of the X-ray fluoroscopy apparatus according to the first embodiment.

[0013] Figure 5 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus according to the first embodiment.

[0014] Figure 6 This is a block diagram showing the overall configuration of an X-ray fluoroscopy apparatus according to the second embodiment.

[0015] Figure 7 This is a diagram for explaining the operation of the interpolation mode (constant display rate) of the X-ray fluoroscopy apparatus according to the second embodiment.

[0016] Figure 8 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus according to the second embodiment.

[0017] Figure 9 This is a block diagram showing the overall configuration of an X-ray fluoroscopy apparatus according to a third embodiment.

[0018] Figure 10 This is a diagram for explaining the operation of the interpolation mode (constant display rate) of the X-ray fluoroscopy apparatus according to the third embodiment.

[0019] Figure 11 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus according to the third embodiment.

[0020] Figure 12 This is a diagram for explaining the operation of the interpolation mode (constant display rate) of the X-ray fluoroscopy apparatus according to the fourth embodiment.

[0021] Figure 13 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus according to the fourth embodiment.

[0022] Explanation of symbols

[0023] 10-X-ray tube, 11-X-ray detector, 12-top plate, 13-movable aperture, 13a-aperture blades, 14-high voltage generator, 20-fluoroscopy switch, 21-irradiation rate operator, 22-interpolation mode operator, 23-camera, 24-microphone, 25-field of view camera, 30-system control device, 30a-operation receiving unit, 31-image processing control device, 32-image processing device, 33-image memory, 34-image display device, 34a-image, 34b-image, 34c-image, 40-operator, 40a-line of sight, 50-subject. DETAILED DESCRIPTION

[0024] Hereinafter, an X-ray fluoroscopy apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0025] <<Implementation Method 1>v

[0026] use Figures 1 to 5 , an X-ray fluoroscopy imaging device according to embodiment 1 is described. Figure 1 is a block diagram showing the overall structure of the X-ray fluoroscopy apparatus according to the first embodiment. Figure 2 is a diagram showing the display of the irradiance operator. Figure 3 is a diagram showing the display of the interpolation mode operator. Figure 4 is a diagram illustrating the operation in interpolation mode (constant display rate). Figure 5 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus.

[0027] The X-ray fluoroscopy apparatus includes a top plate 12 for mounting a subject 50; an X-ray tube 10 for irradiating the subject 50 with X-rays; a movable aperture 13; an X-ray detector 11 for detecting X-rays transmitted through the subject 50; an image processing control device 31 capable of generating X-ray images, including fluoroscopic images and still images, based on the output of the X-ray detector 11; an image processing device 32; an image memory 33; and an image display device 34. The movable aperture 13 includes multiple aperture blades 13a, which adjust the irradiation range of the X-rays emitted from the X-ray tube 10 onto the subject 50. A high-voltage generator 14, which supplies tube current and voltage, is connected to the X-ray tube 10. A system control device 30 is connected to the high-voltage generator 14 and the movable aperture 13 to control their operation. The configuration related to X-ray irradiation and detection, including the X-ray tube 10 and the X-ray detector 11, is referred to herein as an "irradiation device."

[0028] A field of view size manipulator (not shown) is connected to the system control unit 30. The operator can use this manipulator to set the field of view size of the movable aperture 13 to a desired size, etc. Furthermore, a fluoroscopy switch 20 is connected to the system control unit 30. The operator can operate this fluoroscopy switch 20 to instruct on / off X-ray fluoroscopy, etc. The fluoroscopy switch 20 can be a foot-operated switch or a hand-operated switch, but any type of switch may be used.

[0029] Furthermore, an irradiation rate operator 21 is connected to the system control device 30 , and the operator can use the irradiation rate operator 21 to select the irradiation rate of X-ray pulses (imaging frame rate or irradiation frame rate, hereinafter referred to as “irradiation rate”).

[0030] Furthermore, an interpolation mode operator 22 is connected to the system control device 30 , and an operator can select an interpolation mode described later through the interpolation mode operator 22 .

[0031] The system control device 30 includes an operation receiving unit 30a that receives operation signals from the visual field size operator, the fluoroscopy switch 30, and the irradiance operator 21. Two or more of these operators and switches may be combined in one device.

[0032] The X-ray tube 10 is supported by an X-ray tube support (not shown). The X-ray tube support includes an X-ray tube moving mechanism that moves the X-ray tube 10 at least along the longitudinal direction of the top plate 12. A mechanism that raises and lowers the top plate 12 is built into the top plate 12. The X-ray detector 11 includes a detector moving mechanism (not shown) that moves the X-ray detector 11 at least along the longitudinal direction of the top plate 12. A mechanism control device (not shown) is connected to the X-ray tube moving mechanism and the detector rail mechanism to maintain the X-ray tube 10 and the X-ray detector 11 in an opposing positional relationship.

[0033] The image processing control device 31 is capable of executing a fluoroscopic mode and a photographic mode. In the fluoroscopic mode, the X-ray tube 10 irradiates X-ray pulses at an irradiation rate set in the irradiation rate operator 21 under the control of the system control device 30. The image processing control device 31 generates a fluoroscopic image at a rate equal to the set irradiation rate based on the output of the X-ray detector 11. In the photographic mode, the X-ray tube 10 is controlled by the system control device 30 to expose (exposure) only once to X-rays. The X-ray dose of the X-rays exposed in the photographic mode is generally greater than the X-ray dose irradiated by one pulse of the X-ray pulse in the fluoroscopic mode. The image processing control device 31 generates a still image X-ray image based on the output of the X-ray detector 11.

[0034] Each time the image processing control device 31 generates a fluoroscopic image, it stores the generated fluoroscopic image in the image memory 33. The stored fluoroscopic image remains in the image memory 33 until the next fluoroscopic image is generated. In other words, the stored fluoroscopic image is called the LIH (Last Image Hold) image. The fluoroscopic image stored in the image memory 33 is displayed on the connected image display device 34.

[0035] In this embodiment, the description is based on the premise that the fluoroscopic mode is executed. In addition, the irradiation rate of irradiating X-ray pulses and the frame rate of displaying fluoroscopic images (display frame rate, hereinafter referred to as "display rate") are distinguished in this specification.

[0036] The image processing device 32 can execute a normal mode (Normal), a first interpolation mode, and a second interpolation mode.

[0037] In the normal mode, the image processing device 32 displays the fluoroscopic image generated by the image processing control device 31 at a rate equal to the irradiation rate on the image display device 34 (display rate = irradiation rate) without interpolating the fluoroscopic image (interpolation frame) into an interpolation image.

[0038] In the first interpolation mode, the image processing device 32 generates an interpolated image and displays the perspective image and the interpolated image on the image display device 34 (display rate = N times the irradiation rate). The interpolated image is interpolated between perspective images generated at a rate equal to the irradiation rate in such a way that the display rate becomes N times the irradiation rate (N is a pre-set value, for example, 2 times).

[0039] In the second interpolation mode, when fluoroscopy is initiated by turning on the fluoroscopy switch 20, the image processing device 32 displays the fluoroscopy images generated by the image processing control device 31 on the image display device 34 at a rate equal to the irradiation rate set on the operator 21, without interpolating the fluoroscopy images (display rate = irradiation rate). On the other hand, if the operator scans the operator 21 while the fluoroscopy images are being displayed on the image display device 34 to change the irradiation rate to a value lower than the irradiation rate at the start of fluoroscopy, the image processing device 32 generates an interpolated image so that the frame rate (display rate) of the image displayed on the image display device 34 is equal to the irradiation rate at the start of fluoroscopy. Specifically, the image processing device 32 generates an interpolated image, interpolating between fluoroscopy images generated at the rate equal to the changed irradiation rate, and displays the fluoroscopy image and the interpolated image on the image display device 34 at a display rate equal to the irradiation rate at the start of fluoroscopy.

[0040] The generated interpolated image may be stored in the image memory 33 or in another image memory (not shown) connected to the image display device 34 .

[0041] For example, Figure 2 As shown in FIG. 1 , the irradiation rate can be selected by the operator on a screen displayed on the touch panel of the irradiation rate operator 21. Figure 2 In the display, buttons corresponding to the irradiance rates (unit: FPS) of "3.75," "7.5," "15," and "30" are displayed. The selected button (e.g., "30") is displayed so that it can be distinguished from the other buttons. Of course, the irradiance operator 21 is not limited to a touch panel and can also be composed of input devices such as hardware buttons, a mouse, and a keyboard.

[0042] For example, Figure 3 As shown, the interpolation mode can be selected by the operator on a screen displayed on the touch panel of the interpolation mode operator 22. Figure 3 In the display, the buttons corresponding to normal mode, first interpolation mode, and second interpolation mode are "Normal Mode: Interpolation Off" 22a, "First Interpolation Mode: Display Rate N Times the Illumination Rate" 22b, and "Second Interpolation Mode: Constant Display Rate" 22c, respectively. The selected button, "Second Interpolation Mode: Constant Display Rate" 22c, is displayed so that it can be distinguished from the other buttons 22a and 22b. Of course, the interpolation mode operator 22 is not limited to a touch panel; it can also be implemented using hardware buttons, a mouse, a keyboard, or other input devices.

[0043] For example, Figure 4 As shown, in the second interpolation mode, at the start of fluoroscopy, no interpolated image is generated. Instead, a fluoroscopy image generated at a rate equal to the irradiation rate selected by the operator using the irradiation rate operator 21 is displayed on the image display device 34. While the fluoroscopy image is being displayed, if the operator 40 operates the irradiation rate operator 21 to select a button with a lower irradiation rate than that at the start of fluoroscopy to change the irradiation rate, the irradiation rate of the irradiated X-ray pulses is changed, but the display rate displayed on the image display device 34 is controlled to be equal to the irradiation rate at the start of fluoroscopy. In other words, the image processing device 32 generates an interpolated image, which is an interpolation between fluoroscopy images generated at a rate equal to the changed irradiation rate, and displays the fluoroscopy image and the interpolated image on the image display device 34. Thus, the image is displayed on the image display device 34 at a display rate equal to that at the start of fluoroscopy.

[0044] The system control device 30, image processing control device 31, and image processing device 32 are configured, for example, by a computer including a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) and a storage unit such as a memory. The processors implement the functions of the system control device 30, image processing control device 31, and image processing device 32 by reading and executing programs stored in the memory.

[0045] Furthermore, the system control device 30, the image processing control device 31, and the image processing device 32 may be partially or entirely implemented as hardware. For example, the functions of the system control device 30, the image processing control device 31, and the image processing device 32 may be implemented by circuit design using a custom IC such as an ASIC (Application Specific Integrated Circuit) or a programmable IC such as an FPGA (Field-Programmable Gate Array).

[0046] Below, use Figure 5 The operator selects the interpolation mode by operating the interpolation mode operator 22, thereby starting this flowchart. Thereafter, by turning on the fluoroscopy switch 20, X-ray fluoroscopy is started.

[0047] After starting X-ray fluoroscopy, the operator can change the irradiation rate by operating the irradiation rate operator 21 at any time. Also, the operator can turn off X-ray fluoroscopy by operating the fluoroscopy switch 20 at any time.

[0048] exist Figure 5 In the process, steps S111 to S116 are the first interpolation mode (interpolation on (N times the illumination rate)), and steps S121 to S128 are the second interpolation mode (interpolation on (constant display rate)). The processing of the normal mode (interpolation off) is omitted.

[0049] (Step S101)

[0050] In step S101 , the operation accepting unit 30 a of the system control device 30 determines which of the interpolation mode buttons 22 a to 22 c is currently selected in the interpolation mode operator 22 .

[0051] When the selected interpolation mode button is “first interpolation mode: display rate is N times the irradiation rate” 22 b , the system control device 30 proceeds to step S111 .

[0052] When the “second interpolation mode: constant display rate” 22 c is selected, the system control device 30 proceeds to step S121 .

[0053] On the other hand, when the “normal mode: interpolation off” 22 a is selected, the system control device 30 enters the processing of the normal mode.

[0054] (Step S111, Step S112)

[0055] When "1st interpolation mode: display rate is N times the irradiation rate" 22b is selected, the operation receiving unit 30a determines whether it is turned on by the operator pressing the perspective switch 20 in step S111. If it is turned on (yes), the system control device 30 enters step S112 to obtain the irradiation rate F selected in the irradiation rate operator 21.

[0056] (Step S114)

[0057] The system control unit 30 supplies a predetermined fluoroscopy tube voltage and current from the high voltage generator 14 to the X-ray tube 10 at an irradiation rate Fn. The X-ray tube 10 then irradiates the subject 50 with X-ray pulses at an irradiation rate F. The X-rays that have passed through the subject 50 are detected by the X-ray detector 11. The image processing control unit 31 uses the output of the X-ray detector 11 to generate fluoroscopy images at a rate equal to the irradiation rate F.

[0058] (Step S115)

[0059] The image processing device 32 generates an interpolation image that interpolates between the fluoroscopic images so that the display rate becomes N times (for example, 2 times) the irradiation rate F.

[0060] (Step S116)

[0061] The image processing device 32 displays the fluoroscopic image and the generated interpolation image on the image display device 34. As a result, the display rate of the image displayed on the image display device 34 becomes N times the irradiation rate F.

[0062] The system control device 30 returns to step S112 and determines whether the perspective switch 20 remains on. If the perspective switch 20 remains on, steps S112 to S116 are repeated. If the perspective switch 20 is off, the process ends.

[0063] On the other hand, when the “second interpolation mode: constant display rate” 22 c is selected in step S101 , the system control device 30 proceeds to step S121 .

[0064] (Step S121)

[0065] In step S121, the system control device 30 acquires the irradiance F0 currently selected in the irradiance operator 21 as the irradiance when starting fluoroscopy, and stores it in the built-in memory. Figure 4 In the example of FIG, in the irradiation rate operator 21, the operator selects 30 pulses / s as the irradiation rate F0 when starting fluoroscopy, and therefore 30 pulses / s is stored.

[0066] (Steps S122 to S125)

[0067] Next, the system control device 30 performs steps S122 to S125 in the same manner as steps S111 to S124 in the first interpolation mode described above. Specifically, when the operator presses the fluoroscopy switch 20 to turn it on, the system control device 30 obtains the irradiation rate Fn set in the irradiation rate operator 21 and irradiates the subject 50 with X-ray pulses from the X-ray tube 10 at the irradiation rate Fn (here, 30 pulses / s). The image processing control device 31 uses the output of the X-ray detector 11 to generate fluoroscopic images at a rate equal to the irradiation rate Fn (30 frames / s).

[0068] (Step S126)

[0069] The image processing device 32 displays the fluoroscopic image generated in step S125 on the image display device 34 without interpolation. Therefore, the display rate of the image display device 34 is equal to the irradiation rate Fn (= F0) set when starting fluoroscopy (30 frames / s).

[0070] (Step S127)

[0071] Next, the system control device 30 proceeds to step S127 and determines whether the irradiation rate Fn acquired in step S123 is greater than the irradiation rate F0 acquired at the start of fluoroscopy in step S121. If yes, the system control device 30 returns to step S122; if not, the system control device 30 proceeds to step S128.

[0072] When fluoroscopy is started, the irradiance Fn acquired in step S123 is equal to the irradiance F0 acquired in step S121 , and therefore the process returns to step S122 .

[0073] In step S122, the system control device 30 determines whether the fluoroscopy switch 20 is still on. If the fluoroscopy switch 20 is still on, in step S123, the irradiance rate Fn currently set in the irradiance rate operator 21 is acquired, and steps S124 to S126 are repeated. If the fluoroscopy switch 20 is off, the process ends.

[0074] In step S127, the control device 30 again determines whether the irradiation rate Fn obtained in this step S123 is greater than the irradiation rate F0 obtained at the start of fluoroscopy in step S121. If the irradiation rate Fn obtained in this step S123 is changed from the irradiation rate F0 at the start of fluoroscopy, and if the irradiation rate Fn is less than the irradiation rate F0 at the start of fluoroscopy, the process proceeds to step S128.

[0075] For example, in Figure 4 In the example of , in the irradiation rate operator 21, the irradiation rate Fn is changed to 7.5 pulses / s, which is lower than the irradiation rate (30 pulses / s) at the start of fluoroscopy, and therefore the process proceeds to step S128.

[0076] (Step S128)

[0077] In step S128, the image processing device 32 generates an interpolated image 41, which interpolates between the perspective images in such a way that the display rate of the image displayed in the image display device 34 reaches a rate (30 frames / s) equal to the irradiation rate F0 at the start of perspective acquired in step S121.

[0078] (Step S129)

[0079] In step S129, the image processing device 32 displays the fluoroscopic image and the interpolated image on the image display device 34. As a result, the display rate of the image displayed on the image display device 34 becomes the same rate as the initial irradiation rate F0 (30 frames / s).

[0080] Then, the system control device 30 returns to step S122 and repeats steps S123 to S129 until the perspective switch 20 is turned off.

[0081] In addition, when the normal mode (interpolation is turned off) is selected in step S101, X-rays are irradiated at the set irradiation rate F in the same manner as steps S111 to S114, and after the fluoroscopic image is generated at the same rate as the irradiation rate F, it is displayed on the image display device 34 without interpolation.

[0082] As described above, in the X-ray fluoroscopy apparatus of Embodiment 1, in the second interpolation mode "Second interpolation mode: constant display rate" 22c, during fluoroscopy, the operator changes the exposure rate to a lower rate than the rate at the start of fluoroscopy, thereby reducing the exposure rate. However, frame interpolation is performed to maintain the display rate at the same rate as at the start of fluoroscopy. Therefore, during fluoroscopy, during periods when the operator determines that the reliability or real-time nature of the fluoroscopy images is not necessary, the exposure rate can be reduced by the operator 40's operation. This reduces the radiation dose to the operator 40 or the subject while maintaining the display rate. This can alleviate the discomfort that may be caused to a person viewing the fluoroscopy images by changing the display rate mid-process.

[0083] <<Implementation Method 2>v

[0084] use Figures 6 to 8 , an X-ray fluoroscopy imaging device according to embodiment 2 is described.

[0085] The X-ray fluoroscopy apparatus according to the second embodiment is configured so that the irradiation rate can be set by the operator's voice or gesture.

[0086] Figure 6 is a block diagram showing the overall structure of an X-ray fluoroscopy imaging apparatus according to a second embodiment. Figure 7 is a diagram illustrating the operation in interpolation mode (constant display rate). Figure 8 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus.

[0087] The following description will focus on the differences from the first embodiment, and description of the same points as the first embodiment will be appropriately omitted. Figure 6 Among the components of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals and their descriptions are omitted. Figure 8 In the steps of the second embodiment, the same steps as those in the first embodiment are marked with the same symbols and their descriptions are omitted.

[0088] The X-ray fluoroscopy imaging device of the second embodiment includes at least one of a camera 23 and a microphone 24 instead of the irradiation rate operator 21 ( Figure 1 At least one of the camera 23 and the microphone 24 is connected to the system control device 30 , and the operator can select the irradiation rate by indirect operation using at least one of the camera 23 and the microphone 24 without touching the operator.

[0089] The camera 23 captures the operator. The operation receiving unit 30a, for example, uses image recognition processing to identify the operator's body movements based on the captured image (movie or still image). If the identified body movement is a prescribed body movement indicating the selection of an irradiation rate, the operation receiving unit 30a accepts a change in the irradiation rate. Body movements are so-called gestures and include finger or arm movements, head movements, blinking, and mouth movements.

[0090] The microphone 24 captures the operator's voice. The operation accepting unit 30a recognizes the operator's speech from the voice signal through, for example, voice recognition processing, and accepts a change in the irradiation rate if the recognized speech is a predetermined speech instructing selection of the irradiation rate.

[0091] For example, Figure 7 As shown, in the second interpolation mode, when the operator 40 such as the operating doctor selects an irradiation rate lower than the reference rate through indirect operation via the camera 23 or the microphone 24, an interpolated image is generated, and the fluoroscopic image and the interpolated image are displayed on the image display device 34. The interpolated image is interpolated between the fluoroscopic images generated at the set irradiation rate so that the display rate becomes equal to the reference rate. In addition, the display ( Figure 2 ) In the same manner, the irradiation rate selection button can be displayed on a specified display device (not shown).

[0092] Below, use Figure 8 The flowchart is described in more detail.

[0093] In the second embodiment, steps S212 , S221 , and S223 are inserted instead of steps S112 , S121 , and S123 in the first embodiment.

[0094] (Step S101)

[0095] In the same manner as step S101 in the first embodiment, the operation accepting section 30 a of the system control device 30 determines the interpolation mode currently selected in the interpolation mode operator 22 .

[0096] (Step S111)

[0097] When the first interpolation mode is selected, if the perspective switch is turned on in step S111 , the system control device 30 proceeds to step S212 .

[0098] (Step S212)

[0099] The system control device 30 acquires the irradiation rate F selected by the operator through an indirect operation using the camera 23 or the microphone 24 .

[0100] (Steps S113 to S116)

[0101] The system control device 30 performs steps S113 to S116 in the same manner as in the first embodiment.

[0102] On the other hand, when the second interpolation mode is selected in the above-mentioned step S101, the process proceeds to step S221.

[0103] (Step S221)

[0104] In step S221 , the system control device 30 acquires the irradiance F0 selected by the operator through an indirect operation using the camera 23 or the microphone 24 , and stores the acquired irradiance F0 in the built-in memory.

[0105] (Step S122)

[0106] Then, if the see-through switch is turned on in step S122 , the system control device 30 proceeds to step S223 .

[0107] (Step S223)

[0108] The system control device 30 acquires the irradiation rate Fn selected by the operator through an indirect operation using the camera 23 or the microphone 24 .

[0109] (Steps S124 to S129)

[0110] The system control device 30 performs steps S124 to S129 in the same manner as in the first embodiment. Then, the system control device 30 proceeds to step S124.

[0111] In addition, in the case of the normal mode (interpolation is turned off), the same method as the normal mode of the first embodiment is performed.

[0112] As described above, in the X-ray fluoroscopy apparatus according to the second embodiment, the irradiation rate can be selected by the operator's voice or gesture, etc. That is, the operator can easily change the irradiation rate without directly touching the operator.

[0113] Since the configuration, operation, and effects of the X-ray fluoroscopy apparatus of the second embodiment other than those described above are the same as those of the first embodiment, their description will be omitted.

[0114] <<Implementation Method 3>v

[0115] use Figures 9 to 11 , an X-ray fluoroscopy imaging device according to a third embodiment will be described.

[0116] The X-ray fluoroscopy apparatus according to the third embodiment reduces the irradiation rate when the operator 40 is not looking at the image display device 34 .

[0117] Figure 9 : is a block diagram showing the overall structure of an X-ray fluoroscopy imaging apparatus according to a third embodiment. Figure 10 is a diagram illustrating the operation in interpolation mode (constant display rate). Figure 11 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus.

[0118] The following description will focus on the differences from the first embodiment, and description of the same points as the first embodiment will be appropriately omitted. Figure 9 Among the constituent elements of the third embodiment, the same constituent elements as those of the first embodiment are denoted by the same reference numerals and their descriptions are omitted. Figure 11 In the steps of implementation mode 3, the same steps as those in implementation mode 1 are marked with the same symbols and their descriptions are omitted.

[0119] The X-ray fluoroscopy imaging apparatus of the third embodiment is provided with an irradiation rate manipulator 21 ( Figure 1 ) In addition, it is also equipped with a field of view camera 25 that can capture the operator's field of view. The field of view camera 25 is connected to the system control device 30. In the second interpolation mode, when the operating surgeon is not looking at the image display device 34, the irradiation rate is reduced.

[0120] The operator wears the visual field camera 25 to capture at least a portion of the operator's visual field. Preferably, the visual field camera 25 is mounted on the operator's head with its imaging direction facing forward. The method or form of mounting the camera is not limited; for example, it can be mounted in the form of glasses, goggles, or a pen.

[0121] The operation accepting unit 30a determines whether the operator is looking at the screen displaying the X-ray fluoroscopic image on the image display device 34. The operation accepting unit 30a determines whether the fluoroscopic image display screen is included in the captured image (video or still image) through image recognition processing, for example. If the fluoroscopic image display screen is included, it is determined that the operator is looking at the fluoroscopic image display screen. To further improve accuracy, for example, if the fluoroscopic image display screen is within a predetermined distance from a reference position such as the center of the captured image, or if the size (area) of the fluoroscopic image display screen within the captured image is greater than a predetermined value, it can be determined that the operator is looking at the fluoroscopic image display screen. Both the position and area of ​​the fluoroscopic image display screen can also be used for determination. Furthermore, to prevent erroneous determinations such as when the operator is clearly looking at the screen but is determined not to be looking at the screen, the exposure rate can be changed after a certain period of time has passed since the operator has moved their gaze away from the screen.

[0122] If the operation reception unit 30a determines that the operator is looking at the fluoroscopic image display screen, it sets a preset irradiation rate Fp. On the other hand, if the operator is not looking at the fluoroscopic image display screen, it sets a preset irradiation rate Fr. The irradiation rate Fr is lower than the irradiation rate Fp. The values ​​of the irradiation rates Fp and Fr can be configured to be set in advance by the operator.

[0123] For example, Figure 10 As shown, in the second interpolation mode, when an operator 40, such as a surgeon, moves their line of sight 40a away from the fluoroscopic image display screen on the image display device 34, an irradiation rate Fr is automatically selected that is lower than the irradiation rate Fp when the line of sight 40a was focused on the screen. An interpolated image 41 is then generated, and the fluoroscopic image and the interpolated image are displayed on the image display device 34. The interpolated image 41 interpolates between the fluoroscopic images so that the display rate becomes equal to the irradiation rate Fp.

[0124] Below, use Figure 11 The operation of the X-ray fluoroscopy imaging device according to the third embodiment will be described in more detail with reference to the flowchart of FIG.

[0125] In embodiment 3, as Figure 11 As shown, steps S301 to S309 are executed instead of steps S121 to S129 in the second interpolation mode of the first embodiment.

[0126] (Step S101)

[0127] In step S101 , the system control device 30 determines the interpolation mode currently selected in the interpolation mode operator 22 in the same manner as in the first embodiment.

[0128] (Steps S111 to S116)

[0129] In the case of the first interpolation mode, steps S111 to S116 are performed in the same manner as in the first embodiment.

[0130] (Step S301)

[0131] When the operator presses the fluoroscopy switch 20 and the fluoroscopy switch 20 is turned on, the system control device 30 proceeds to step S302 .

[0132] (Step S302)

[0133] The operation receiving unit 30a of the system control device 30 determines whether the operator is looking at the fluoroscopic image display screen. If the operator is looking at the fluoroscopic image display screen (Yes), the system control device 30 proceeds to step S303. If the operator is not looking at the fluoroscopic image display screen (No), the system control device 30 proceeds to step S306.

[0134] (Step S303)

[0135] In step S303 , the system control device 30 irradiates X-ray pulses at a preset irradiation rate Fp.

[0136] (Step S304)

[0137] The image processing control device 31 generates a fluoroscopic image at a rate equal to the irradiation rate Fp using the output of the X-ray detector 11 .

[0138] (Step S305)

[0139] The image processing device 32 displays the fluoroscopic image on the image display device 34 without interpolating the interpolated image. The display rate becomes equal to the initial irradiation rate Fp. The system control device 30 returns to step S301.

[0140] (Step S306)

[0141] On the other hand, when the system control device 30 determines in step S302 that the operator is not looking at the fluoroscopic image display screen, in step S306 , the system control device 30 irradiates X-ray pulses at a preset irradiation rate Fr.

[0142] (Step S307)

[0143] The image processing control device 31 generates a fluoroscopic image at a rate equal to the irradiation rate Fr using the output of the X-ray detector 11 .

[0144] (Step S308)

[0145] In step S308 , the image processing device 32 generates an interpolation image 41 that interpolates between the fluoroscopic images so that the display rate of the image displayed on the image display device 34 becomes equal to the irradiation rate Fp.

[0146] (Step S129)

[0147] In step S129, the image processing device 32 displays the perspective image and the interpolated image on the image display device 34. As a result, the display rate of the image displayed on the image display device 34 becomes equal to the display rate in step S305 (=Fp).

[0148] Then, the system control device 30 returns to step S301.

[0149] As described above, in Embodiment 3, the exposure rate is set to a low level when the operator is not looking at the screen of the image display device 34 displaying the fluoroscopic images, thereby reducing the radiation dose to the operator 40 and the subject. Furthermore, during the period when the operator is not looking at the screen and the exposure rate is set to a low level, the display rate is not interpolated using interpolated images, maintaining the same rate as when the operator was looking at the fluoroscopic images. This ensures that the display rate remains constant throughout the fluoroscopic examination, even when viewing a recorded video of the fluoroscopic images later, minimizing the discomfort associated with changes in the display rate.

[0150] <<Implementation Method 4>v

[0151] use Figures 12 and 13 , an X-ray fluoroscopy imaging device according to a fourth embodiment is described.

[0152] In the X-ray fluoroscopy imaging apparatus of the fourth embodiment, when frame interpolation is performed in the second interpolation mode, an image 34c showing that an interpolated image is being displayed is as shown in FIG. Figure 12 The image is additionally displayed in the image display device 34. Figure 12 In the example, "FRC" (Frame Rate Conversion) is displayed.

[0153] Figure 12 1 is a diagram illustrating the operation of the interpolation mode (constant display rate) of the fourth embodiment. Figure 13 This is a flowchart showing the operation of the X-ray fluoroscopy apparatus.

[0154] The following description will focus on the differences from the first embodiment, and description of the same points as the first embodiment will be appropriately omitted. Figure 13 In the steps of embodiment 4, the same steps as those in embodiment 1 are marked with the same symbols and their descriptions are omitted.

[0155] The X-ray fluoroscopic imaging device of the fourth embodiment has the same components as those of the first embodiment ( Figure 1 ).

[0156] For example, Figure 12As shown, in the second interpolation mode, during the period of irradiation at the irradiation rate set at the start of fluoroscopy, no interpolated image is generated, and the fluoroscopy image (normal image) generated at this rate is displayed on the image display device 34 (34a). During the fluoroscopy process, when the operator 40 such as the operating doctor operates the irradiation rate operator 21 to change the irradiation rate to a lower irradiation rate than when the fluoroscopy was started, an interpolated image is generated, and the fluoroscopy image and the interpolated image are displayed on the image display device 34 (34b), and the interpolated image is interpolated between the fluoroscopy images generated at the set irradiation rate in such a way that the display rate becomes equal to the display rate at the start of fluoroscopy. In the case of frame interpolation, an image 34c indicating that the interpolated image is being displayed is displayed on the image display device 34. Figure 13 In the display, it is displayed as "FRC" (FrameRate Conversion).

[0157] Below, use Figure 13 The flowchart is described in more detail.

[0158] In the fourth embodiment, steps S101 , S111 to S116 , and S121 to S129 are performed in the same manner as in the first embodiment, and step S401 is inserted immediately after step S129 .

[0159] (Step S401)

[0160] In step S401, the image processing device 32 causes the image display device 34 to additionally display an image 34c indicating that the interpolated image is being displayed. The system control device 30 then returns to step S122. Furthermore, the image processing device 32 keeps displaying the image 34c until a "Yes" determination is made in step S127.

[0161] In addition, the same processing as step S401 may be performed immediately after step S116.

[0162] In the fourth embodiment, at least when frame interpolation is being executed in the second interpolation mode, image 34c is displayed. This image 34c indicates that the interpolated image is being displayed, allowing the operator to intuitively recognize that frame interpolation is being performed. Furthermore, when a non-operator is looking at the screen, image 34c indicating that the interpolated image is being displayed allows the operator to recognize that frame interpolation is being performed.

[0163] Of course, in Embodiments 1 to 3, when frame interpolation is enabled, an image indicating that an interpolated image is being displayed may be displayed.

[0164] The present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the above-described embodiments are described in detail to facilitate understanding of the present invention and are not necessarily limited to embodiments having all of the described structures. Furthermore, a portion of the structure of a particular embodiment can be replaced with the structure of another embodiment, or the structure of another embodiment can be added.

Claims

1. An X-ray fluoroscopic imaging device, characterized in that: have: an irradiation device comprising an X-ray tube for irradiating an object with X-rays and an X-ray detector for detecting the X-rays that have passed through the object; a system control device for controlling the irradiation rate of the X-ray pulses of the irradiation device; an image processing control device that generates a fluoroscopic image at a rate corresponding to the irradiation rate based on the output of the X-ray detector; and an image processing device that displays the perspective image generated by the image processing control device on an image display device, The system control device can change the irradiation rate according to the operator's operation. The image processing device generates interpolated frames so that the frame rate of the image displayed on the image display device becomes equal to the irradiation rate at the start of fluoroscopy when the irradiation rate is changed to a value lower than the irradiation rate at the start of fluoroscopy while the fluoroscopy image is displayed on the image display device, and displays the fluoroscopy image and the interpolated frames on the image display device.

2. The X-ray fluoroscopic imaging device according to claim 1, wherein The X-ray fluoroscopic imaging device includes an irradiation rate operator for receiving the setting of the irradiation rate from the operator. The system control device irradiates the X-ray pulses from the irradiation device at the irradiation rate received by the irradiation rate operator.

3. The X-ray fluoroscopic imaging device according to claim 1, wherein: The X-ray fluoroscopy device includes a microphone for picking up the operator's voice or a camera for capturing the operator's body movements. The system control device changes the irradiation rate according to a selection operation performed by a sound obtained by using the microphone or a selection operation performed by a body movement obtained by using the camera.

4. The X-ray fluoroscopic imaging device according to claim 1, wherein The X-ray fluoroscopic imaging device includes a field of view camera mounted on the operator's head. The system control device changes the irradiation rate according to at least one of a position and a size of a screen of the image display device included in an image captured by the field of view camera.

5. The X-ray fluoroscopic imaging device according to claim 1, wherein The system control device performs the following processing according to at least one of the position and size of the screen of the image display device: When it is determined that the operator is not looking at the screen, the irradiation rate is reduced. When it is determined that the operator is looking at the screen, the irradiation rate is set as a reference rate.

6. The X-ray fluoroscopic imaging device according to any one of claims 1 to 5, characterized in that: When displaying the interpolated frame, the image processing device causes the image display device to display an image indicating that the interpolated frame is being displayed.

7. An image processing method, which is a fluoroscopic image photography method based on an X-ray fluoroscopic imaging device, characterized in that: include: When receiving an instruction to start fluoroscopy from an operator, irradiating the subject with X-ray pulses at a preset irradiation rate, generating fluoroscopic images at a rate equal to the irradiation rate, and displaying the images on a connected image display device; During fluoroscopy, when the irradiation rate is changed, the subject is irradiated with X-ray pulses at the changed irradiation rate, and fluoroscopy images are generated at a rate equal to the changed irradiation rate; and A step of determining whether the changed irradiation rate is smaller than the irradiation rate at the start of fluoroscopy, and if the changed irradiation rate is smaller than the irradiation rate at the start of fluoroscopy, generating interpolated frames at a rate equal to the irradiation rate at the start of fluoroscopy so that the image is displayed on the image display device, and displaying the fluoroscopy image generated at a rate equal to the changed irradiation rate and the interpolated frames on the image display device.

Images