JP2664934B2 - Pulsed X-ray fluoroscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an X using an image intensifier.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluoroscopy apparatus, and particularly to a technique which is effective when applied to a pulsed X-ray intermittent irradiation technique in a pulsed X-ray fluoroscopy apparatus.

(Prior art)

Conventional pulsed X-ray fluoroscopes that perform fluoroscopy using pulsed X-rays do not emit X-rays by intermittently outputting pulsed X-rays, that is, so-called X-rays, in order to reduce the exposure dose. Meanwhile, a method of displaying a memory image is employed.

[Problems to be solved by the invention] However, in the conventional pulse X-ray fluoroscope,
The set value of the intermittent interval of the X-ray intermittent irradiation mechanism is variable,
It is necessary to change the set value by the operation switch on the panel. For this reason, during the movement of the visual field, it is possible to reduce the number of image frames to reduce the X-ray exposure, but there are the following problems.

That is, it is only necessary that the visual field movement position is described in the image. For example, a clear image is required during the operation (from the start to the end), and therefore, the X-ray dose must be increased. In general, the person who moves the field of view (doctor) and the person who changes the switch (X-ray technician) are often different, so that if the above operation is frequently performed, the operation becomes complicated. Was.

The present invention has been made to solve the above problems.

An object of the present invention is to provide a technique capable of obtaining a clear image and reducing the X-ray exposure in a pulsed X-ray fluoroscope.

The above and other objects and novel features of the present invention are as follows.
It will become apparent from the description of the present specification and the accompanying drawings.

[Means for solving the problem]

In order to achieve such an object, the present invention provides an image system comprising an X-ray tube and an image intensifier which are arranged to face each other, and an image system which is arranged between the X-ray tube and the image intensifier. A fluoroscopy table on which a subject to be placed is placed, wherein at least one of the imaging system and the fluoroscopy table relatively moves with respect to the other (when one of the imaging system and the fluoroscopy table is fixed) A pulsed X-ray fluoroscope that performs visible light imaging of an X-ray transmitted through the subject by an image intensifier along at least the body axis direction of the subject, wherein the imaging system and the fluoroscopic table A detecting device for detecting one of the moving speeds, and an irradiation interval of X-rays from the X-ray tube is increased when the moving speed detected by the detecting device is high. And a control device for shortening the interval of X-ray exposure from the X-ray tube when the moving speed is low.

[Action]

According to the above means, the amount of movement of the fluoroscopic table or the image system is detected, and the X-ray pulse interval is changed based on the detection signal, thereby automatically changing the intermittent X-ray exposure interval during the movement of the visual field. Therefore, if the moving speed of one of the video system and the fluoroscopic table is high, the X-ray irradiation interval from the X-ray tube is lengthened, and if the moving speed is low, X-ray exposure interval is shortened), the amount of X-ray exposure can be reduced, and a clear image can be obtained.

(Example of the invention)

Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a block diagram showing an overall schematic configuration of an embodiment of a pulse X-ray fluoroscope according to the present invention, and FIG. 2 is a block diagram showing a schematic configuration of an X-ray intermittent exposure control device shown in FIG. FIG.

In the pulse X-ray fluoroscope of the present embodiment, as shown in FIG. 1, X-rays are emitted from the X-ray tube 1 by an X-ray irradiation signal from the X-ray generator 2.

The X-ray transmitted through the subject 11 is incident on an image intensifier (hereinafter, referred to as II) 3, and the transmitted X-ray is converted into a light image.

The output image of II3 is converted into an electric signal by the television camera 4. The television camera 4 is controlled by a camera control device 5.

The camera control device 5 controls television scanning by an external synchronization method using a horizontal synchronization control signal (HD) and a vertical synchronization control signal (VD) from the X-ray intermittent exposure control device 6. As another example, for example, a horizontal synchronization control signal (HD) and a vertical synchronization control signal (VD) may be output from the camera control device 5, and the X-ray intermittent exposure control may be performed using the signals.

As shown in FIG. 2, the X-ray intermittent emission control device 6 includes a television synchronization signal generation circuit 21, a frequency division circuit 22, a decoder 23 for generating a pulse signal corresponding to the movement of the fluoroscopic table 12, and a camera control. A frame memory 24 for storing a video signal from the device 5; a frame memory write signal generating circuit 25 for generating a data write signal for writing data into the frame memory 24 and a monitor display switching signal; The signal is displayed directly on the display device 7 or once recorded in the frame memory 24,
It comprises a monitor display switching circuit 26 and an X-ray output switching circuit 27 for displaying or switching the image.

As shown in FIG. 1, the rotational force of the motor 8 for moving the see-through table 12 is transmitted to the table moving driver 9 by a belt 13 or the like. A rotor 10 for detecting the movement of the see-through table 12 is rotatably provided on the belt 13. The rotor 10 is attached to, for example, a rotation shaft of a rotary encoder 14.

In addition, the rotation may be transmitted to the rotation shaft of the rotary encoder via a gear, a roller, or the like.

A pulse signal during the movement of the see-through table 12 is output from the rotary encoder 14 and input to a decoder 23 shown in FIG. The decoder 23 converts the fluoroscopic table movement pulse signal sent from the rotary encoder 14 into a level signal. For example, the signal is converted so that the signal becomes "1" when the see-through table movement pulse signal is output, and becomes "0" when the see-through table movement pulse signal is not output. This can be easily created by using, for example, a trigger type mono-multi vibrator.
Further, a counter and a decoder may be combined.

The frame memory 24 records a video signal from the television camera 4 in units of one field.

The frame memory write signal creation circuit 25 does not output a write signal when the fluoroscopic table 12 is not moving, and when the fluoroscopic table 12 moves, the frame memory
Writing to 24 is output intermittently in conjunction with the X-ray exposure signal.

Next, the operation of the pulse X-ray fluoroscope according to the present embodiment will be described.

FIG. 3 is a time chart for explaining the operation of the pulse X-ray fluoroscope of this embodiment shown in FIGS. 1 and 2.

In FIG. 3, (a) is a television synchronization signal generation circuit 21.
VD (vertical synchronization signal) output from
Output at 16.7m / sec.

(B) is a signal indicating that the fluoroscopic table is being moved, which is converted from the fluoroscopic table movement pulse signal into a level signal by the retrigger monomultivibrator.

 (C) is a signal synchronized with VD.

(D) to (G) are 1 / 2VD signal, 1 / 3VD signal, 1 / 4VD signal, and 1 / 8VD signal obtained by dividing the VD signal, respectively.

(H) and (I) show the see-through table movement signal (B).
This is a signal whose phase has been corrected using the 1 / 3VD signal to 1 / 8VD signal. (H) is when the moving speed of the fluoroscopic table is slow, and (I) is when the moving speed of the fluoroscopic table is fast. is there. Switching control of the X-ray output and the like are performed by these signals (h) and (h).

(Nu) is an X-ray emission signal, (l) is a data write signal to the frame memory 24, and (ヲ) is a monitor display switching signal.

1 and 2, when the driving motor 8 is driven, the rotational force of the driving motor 8 is transmitted to the table moving drive unit 9 by a belt 13 or the like, and the see-through table 12 is moved. At this time, the rotor 10 for detecting the movement of the see-through table provided on the belt 13 rotates, and a pulse signal during the movement of the transparent table is output from the rotary encoder 14 to the decoder 23 shown in FIG. Is entered. The decoder 23 converts the fluoroscopic table movement pulse signal sent from the rotary encoder 14 into a level signal and outputs, for example, the signal (b) (the signal of “1”) in FIG. This signal (b) is input to the frame memory write signal creation circuit 25 and the X-ray output switching circuit 27. The data write signal (R) to the frame memory 24 is generated by the signal (A) and the signal (B) shown in FIG. Is recorded in units of one field. That is, the frame memory write signal generation circuit 25 does not output the data write signal when the table 12 is not moving, and when the fluoroscopic table 12 moves, the writing to the frame memory 24 is performed by the X-ray exposure signal. Output intermittently in conjunction with.

On the other hand, the X-ray output signal (nu) is supplied to the signals (a), (b), and (b) of FIG.
It is created by (h) and (li). The X-ray emission signal (nu) is input to the X-ray generator 2, and the X-ray tube 1 emits X-rays based on the X-ray emission signal (nu).

The X-ray transmitted through the subject 11 is incident on II3, and the transmitted X-ray is converted into a light image.

The output image of II3 is converted into an electric signal by the television camera 4 and stored in the frame memory 24 according to the data write signal (R). A data write signal (R) for writing data to the frame memory 24 and a monitor display switching signal (E) are used to generate a frame memory write signal.
Created at 25. The monitor display switching circuit 26 switches between displaying the video signal from the camera control device 5 directly on the display device 7 or temporarily storing the video signal in the frame memory 24 and displaying the image. The video signal from the device 5 is displayed on the display device 7.

As can be understood from the above description, according to the present embodiment, the amount of movement of the fluoroscopic table 12 is detected, and the X-ray pulse interval is changed based on the detection signal.
Since the intermittent X-ray exposure interval is automatically changed, the amount of X-ray exposure can be reduced and a clear image can be obtained.

That is, when the fluoroscopic table 12 is moved, the X-ray exposure time can be reduced to 1/3 or less, and the exposure of the examinee 11 can be reduced. While the see-through table 12 is moving, the frame is dropped, but there is no problem in use because it is sufficient to confirm the position.

In the case where the imaging system is moved instead of moving the fluoroscopic table 12, the X-ray exposure time can be reduced to 1/3 or less by the same method as in the above embodiment, and the exposure of the examinee 11 is reduced. be able to.

As mentioned above, although the present invention was explained concretely based on an example, the present invention is not limited to the above-mentioned example.
It goes without saying that various changes can be made without departing from the scope of the invention.

〔The invention's effect〕

As described above, according to the present invention, the moving amount of the fluoroscopic table or the image system is detected, and the X-ray pulse interval is changed based on the detection signal, so that during the visual field movement,
Since the intermittent X-ray exposure interval is automatically changed, the amount of X-ray exposure can be reduced and a clear image can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall schematic configuration of an embodiment of a pulse X-ray fluoroscope according to the present invention, and FIG. 2 is a block diagram showing a schematic configuration of an X-ray intermittent exposure control device shown in FIG. FIG. 3 shows the pulse X of the present embodiment shown in FIG. 1 and FIG.
It is a time chart for explaining operation of a fluoroscope. In the figure, 1 ... X-ray tube, 2 ... X-ray generator, 3 ... I.
I., 4 TV camera, 5 Camera control device, 6
.. X-ray intermittent exposure control device, 7... Display device, 8... Movement drive motor, 9... Table movement drive unit, 10... Rotor, 12... Fluoroscopic table, 13. …… Rotary encoder, 21 …… TV synchronization signal generation circuit, 22…
... frequency divider, 23 ... decoder, 24 ... frame memory,
25 ... frame memory write signal generation circuit, 26 ... monitor display switching circuit, 27 ... X-ray output switching circuit.

Claims (1)

(57) [Claims] 1. An imaging system comprising an X-ray tube and an image intensifier arranged opposite to each other, and a fluoroscope for placing a subject disposed between the X-ray tube and the image intensifier. At least one of the imaging system and the fluoroscopic table is relatively moved with respect to the other, and visible light imaging by an image intensifier of X-rays transmitted through the subject is performed on at least the body of the subject. In a pulsed X-ray fluoroscope that is performed along the axial direction, a detecting device that detects a moving speed of one of the image-based device and the fluoroscopic table, the detecting device detects the moving speed when the moving speed is high. A control device for increasing the interval of X-ray exposure from the X-ray tube and shortening the interval of X-ray exposure from the X-ray tube when the moving speed is low. A pulse X-ray fluoroscopy apparatus, characterized in that are.