JPS6264187A - X-ray perspective photographing device - Google Patents

Abstract

PURPOSE:To stabilize the output of a TV camera and to make a picture easy t see and to improve the operability of the device by disposing a light emitting body between an image intensifier and a TV camera and providing a light emission control circuit. CONSTITUTION:An X-ray generating device 1 consists of an X-ray tube 2 and an X-ray generator 3, and emits X-rays under the I/O instruction from the CPU of an image processing part 6. The image intensifier I.I4 emits light by the incident X-ray from the tube 2 that transmits an object 19 to be measured. In this case, the light emitting body 11 is disposed between the I.I4 and the TV camera 5, and the light emission control circuit 12 controlling said body 11 is provided. The circuit 12 controls the body 11 to emit with the timing when the X-ray emission interval is short during the time when said interval is long. As a result, even in case where the emission interval of the X-ray is changed during photographing, the quantity of the incident light to the camera 5 can be made approximately constant. Therefore, the output level of the camera 5 is stabilized and the resulting picture is made easy to see, and the operability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to digital subtraction angiography, which takes a fluoroscopic image of a subject by emitting X-rays in a pulsed manner.
The present invention relates to an X-ray fluoroscopic imaging device such as a device (hereinafter abbreviated as rl?S AJ), and particularly to an X-ray fluoroscopic imaging device that can stabilize the output level of a television camera even when changing the emission interval of X-rays midway.

2. Description of the Related Art A conventional X-ray fluoroscopy apparatus of this type includes an X-ray generator 1 comprising an X-ray tube 2 and an X-ray generator 3, as shown in FIG.
, an image intensifier (hereinafter abbreviated as r1.IJ) 4, a television camera 5, an image processing section 6, and a television monitor 7. Note that the reference numeral 8 is an optical system provided in front of the television camera 5. and,
Central processing bag fi' of image processing section 6! (Ministry of Illustrations 1118)
X-rays are emitted from the X-ray tube 2 of the X-ray generator 1 according to input/output commands from 1. The light enters I4 and emits light, and this light enters television camera 5 and is converted into a video signal.

2, the xg radiation from the X-ray generator 1 is the 7th
The basic timing is the vertical synchronizing signal S1 of the television camera 5 shown in FIG. 7(a), and every time a predetermined number of vertical synchronizing signals S are counted, A ray radiation signal S2 is sent out, and X-rays are radiated from the X-ray tube 2 at the timing of this X-ray radiation signal S2. Therefore, this X-ray passes through the subject 9 and 1. The output signal S of the television camera 5, which causes the I4 to emit light and converts the light into a video signal, appears in synchronization with the X-ray radiation signal S2, as shown in FIG. 7(c).

Problems to be Solved by the Invention However, when performing DSA imaging in pulse mode with such an X-ray fluoroscopic imaging device, as shown in FIG. There were times when the X-ray emission interval was changed between the first and second half of the imaging session.

It is generally known that when the amount of light incident on a television camera changes, the output level of the television camera changes slightly due to the rising characteristics and afterimage characteristics of the image pickup tube. Therefore, in the above case, for example, 10 times/
The first half is imaged at an X-ray emission interval of sec, and 3°/3 times/s.
The output level of the television camera 5 fluctuated in the latter half of the photographing at the X-ray emission interval of ec. That is,
In the first half of FIG. 7(b) where the X-ray emission interval is short, the amount of light incident on the TV camera 5 is large and its output level is high, and in the second half where the X-ray emission interval is long, the amount of light incident on the TV camera 5 is large. The amount of light decreased and the output level decreased. When a subtraction image is created by taking a difference between images before and after the X-ray emission interval changes in DSA imaging in such a state, the fluctuation in the output level of the television camera 5 appears to be emphasized many times over. That will happen. That is, the brightness of each individual image before subtraction changes slightly, and the brightness of a subtraction image created from these images changes from one image to another, resulting in an image that is difficult to see. Therefore, with respect to the subtraction images obtained in this manner, the brightness W (level adjustment) of the image must be adjusted for each image, resulting in poor operability. Therefore, an object of the present invention is to solve such problems.

Means for Solving the Problems Means of the present invention for solving the above problems includes an X-ray generator, an image intensifier, a television camera,
In the xi fluoroscopic imaging apparatus having an image processing unit and a television monitor, a light emitting body is disposed between the image intensifier and the television camera, and the light emitting body is arranged at an interval between the X-rays emitted from the X-ray generating device. When the X-ray emission interval is long, this is achieved by providing a light emission control circuit that causes the light to be emitted in a pulsed manner in synchronization with the timing when the X-ray emission interval is short.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an X-ray fluoroscopic imaging apparatus according to the present invention. This X-ray fluoroscopic imaging device performs DSA imaging in a pulse mode using a beam blanking method, for example, and includes an X-ray generator 1, an image intensifier (r1.IJ) 4, and a television camera. 5, an image processing section 6, and a television monitor 7.

The X-ray generator 1 includes a central processing unit (
It emits X-rays in response to input/output commands from a device (not shown), and consists of an xi tube 2 and an X-ray generator 3. Said 1. I4
The X-ray tube 2 receives the X-rays emitted from the X-ray tube 2 and transmitted through the subject 9, and emits light according to the amount of the incident X-rays. In addition, the television camera 5 is configured as described in 1. It inputs I4 light and converts it into a video signal, and there is an image pickup tube inside it.
and, before that, the above 1. An optical system 8 consisting of a plurality of lenses 8a and 8b is provided to guide the light from I4. Furthermore, the image processing section 6 digitizes the video signal from the television camera 5 and then performs necessary calculations to process the image, and also provides input/output instructions to the X-ray generator 1 and the light emission control circuit 1, which will be described later. etc. to control them. Further, the television monitor 7 is
The image processed by the image processing section 6 is displayed.

Here, in the present invention, the above 1. A light emitter 11 is disposed between the I4 and the television camera 5, and a light emission control circuit 12 for controlling the light emission of the light emitter 11 is provided. The light emitting body 11 emits light as appropriate in order to stabilize the output level of the television camera 5, similar to the light emission of 1 and I4 by X-rays, and is made of, for example, a light emitting diode.
As shown in FIG. 1, it is provided between lenses 8a and 8b of optical system 8. Further, the 1 light emission control circuit 12 controls the light emitting body 11 to X! When the XwA emission interval from the @ generator 1 is long, it emits light in a pulsed manner in accordance with the timing when the X-ray emission interval is short, and as shown in FIG. , transistor 15. The counter 13 is
This counter 1 determines the time that the light emitter 11 lights up.
3 receives a clock signal CLK, a timer start input/output command I10, and timer set data D from the central processing unit in the image processing section 6.

Now, if the light emitter 11 is to be made to emit light in a pulsed manner for a period of, for example, 10 m5ec, first, the image processing section 6 sends out the numerical value "10" as the timer set data D, and at the same time, the timer start input/output command I10 is sent out. Input to counter 13. At this time, the counter 13 has, for example, IKIIz (period 1) as shown in FIG. 3(a).
m5ec) clock signal CLK is input, and
The timer set data It 10 +1 is set by inputting the timer start input/output commands ◯/◯ shown in FIG. 2(b). The timer start input/output command unit 10 is
At the same time as input to counter 13, flip-flop 1
Also input to the set side S of 4. As a result, the output Q of the flip-flop 14 is set to "1". Then, when the output of this flip-flop 14 becomes "I I+", the transistor 15 is turned on, and the light emitting body 11
A current flows through the light emitting body 11, and the light emitting body 11 emits light. That is,
As shown in FIGS. 3(b) and 3(d), the light emitting body 11 is turned on at the same time as the timer start input/output command ○ is input. From this state, the counter 13 subtracts the clock signal CLK from the image processing section 6 by 1, and when the clock signal CLK is counted 10 times, the set counter value becomes 1'0'', and the counter 13 subtracts the clock signal CLK from the image processing section 6 by 1. As shown in FIG. 3(c), the counter borrow signal CB is output.This occurs IQmsec after the timer start input/output command I10.

The counter borrow signal CB is applied to the flip-flop 14.
The flip-flop 14 is reset by inputting the signal to the reset side R of the flip-flop 14. At this time, the output of the flip-flop 14 becomes 110'', the transistor 15 is turned off, and no current flows through the light emitter 11. Therefore, the light emitting body 11 stops emitting light. )
, (d), the light emitter 11 is turned off at the same time as the counter borrow signal CB is output from the counter 13. As described above, the light emission control circuit 12 controls the light emission of the light emitter 11. The light emission time can be adjusted by appropriately selecting the clock signal CLK and timer set data D.

Next, the operation of the X-ray fluoroscopy apparatus configured as described above will be explained with reference to the timing diagram shown in FIG. x from X-ray generator 1! The basic timing for emitting iA is the vertical synchronizing signal S of the television camera 5 shown in FIG. As shown in (b), an X-ray radiation signal S2 is sent out, and X-rays are emitted from the X-ray tube 2 at the timing of this X-ray radiation signal S2. The vertical synchronization signal S serves as a reference for capturing incident light in the television camera 5, and in FIG. 4(a), for example, the period is 33.
This is the clock signal for m5ec.

In this case, the interval of X-ray radiation is changed between the first half and the second half of the imaging, for example, 10 times/see in the first half and 3.3 times/SOc in the second half. Therefore, one X-ray radiation signal S2 shown in FIG. 4(b) is output for every three vertical synchronization signals S1 in the first half of the five imaging sessions, and one is output for every three vertical synchronization signals S1 in the second half. One is output for each. Then, in synchronization with this X-ray radiation signal S2, as shown in FIG. 4(d),
Light enters the television camera 5 and its output signal S3 appears. In such a state, in the latter half of the imaging in which the X-ray emission interval is 3.3 times/sec as shown in FIG. 4(b), the output signal S of the television camera 5 becomes sparse and its output level fluctuates. I will do it. Therefore, under the control of the light emission control circuit 12 shown in FIG. 2, as shown in FIG. 11 is caused to emit light in a pulsed manner for a predetermined period of time. As a result, as shown in FIG. 4(d), the output signals S and l shown by the broken line are cursed at regular intervals between the output signal S3 shown by the solid line in the second half of the shooting, and the Output signal S of the television camera 5 at generally the same intervals.

and S, / will appear, and the output level can be stabilized.

Next, the procedure for emitting X-rays from the X-ray generator 1 and emitting light from the light emitter 11 in the above operation will be explained with reference to the flowchart shown in FIG. First, the image processing section 6 counts the vertical synchronizing signals S shown in FIG. 4(a) and determines whether the vertical synchronizing signal S1 is the third one (step 2). Here, if it is still the 1st or 2nd item, 11 N O
Proceed to the 12th side, wait for a while, and when you count the third one, "Y"
Proceed to the ES” side.

Next, it is determined whether or not the X-ray emission signal S2 shown in FIG. 4(b) is currently in the first half of imaging at a short interval of 10 times/see (step 2).

At this point, we are still at the beginning of shooting, and we proceed to the "YES" side. Then, X-rays are emitted from the X-ray generator 1 in accordance with the X-ray radiation signal S2 output every third vertical synchronization signal S□ (step □). next.

It is determined whether the predetermined number of times of photographing has been completed (step ■). Here, it is still the first half of the photographing, and the process advances to the jjN○'' side and returns to before step ■.In the same manner, the above steps ■→■→■→■ are repeated until the first half of the photographing is completed.

When the first half of the predetermined number of shots is completed, Fig. 4 (
Moving to the second half of the imaging, where the X-ray radiation signal S2 shown in b) is at a long interval of 3.3 times/sec, step ■ is ' NO
Next, the image processing unit 6 determines whether or not it is the third time to count the vertical synchronization signals S□ by three as shown in FIG. 4(a) (step ■). Since I have just moved to ``No'' and have not reached the first time.
As a result, as shown in FIG. 2, the image processing unit 6 sends the clock signal CLK, the timer start input/output command I10, and the timer set data D to the light emission control circuit 12. As shown in FIG. 4(c), the light emission control circuit 12 outputs the ON signal S4 for the light emitter 11 at the third vertical synchronization signal S□ to cause the light emitter 11 to shine (step 2). Next, it is determined whether or not the predetermined number of shots has been completed (step ■).The second half of the shooting has just started here, so the process advances to the "NO" side and returns to before step ■.In the same manner, Immediately before counting the three vertical synchronizing signals S1 for the third time, that is, while counting the eight vertical synchronizing signals S□, the above steps ■→■→■→■→■ are repeated.

During that time, as shown in Figure 4(c),
The light emission control circuit 12 outputs an ON signal S4 for the light emitter 11 every third vertical synchronization signal S to cause the light emitter 11 to shine (step 2). Then, when the three vertical synchronizing signals S1 are counted for the third time, that is, when nine vertical synchronizing signals S1 are counted, step (2) advances to the "YES" side. At this timing, as shown in FIG. 4(b), it is the timing to emit X-rays, so the X-ray radiation signal S2 output every ninth vertical synchronization signal S causes The generator 1 emits xi (step ■), and then it is determined whether the predetermined number of shots has been completed (step ■
). At this point, we are still in the second half of filming, and 11 N○
Proceed to the `` side and return to the front of Step ■.
Depending on whether or not the vertical synchronization signal S1 is received for the third time, the step ■→■→■→■→■ or the step ■→■→■→■→■ is repeated. In this way, images are taken one after another, and when the predetermined number of images is completed, step (2) proceeds to the "YES" side, and everything is completed.

In the above explanation, the light emitting body 11 is a light emitting diode, but the present invention is not limited to this, and any light emitting device can be used as long as it can emit light in a pulsed manner similar to the light emission of 1, I by X-rays. It may be something.

Effects of the Invention As explained above, the present invention has the following features: 1. A light emitting body 11 is arranged between I4 and the television camera 5, and this light emitting body 11
Since the light emission control circuit 12 is provided to emit light in a pulsed manner, when the X-ray emission interval from the X-ray generator 1 is long, the light emission control circuit 12 controls the timing to synchronize with the timing when the X-ray emission interval is short. The light emitter 11 can be caused to emit light. Therefore, even when changing the radiation interval of X-rays during imaging, the amount of light incident on the television camera 5 can be kept approximately constant, and the output signal S 31S 3/ appears, and the output level can be stabilized. From this, in DSA imaging in pulse mode, even if a subtraction image is created by taking the difference between images before and after the X-ray emission interval changes, the brightness of each image before subtraction remains approximately constant. Therefore, the brightness of the subtraction image can be kept constant to provide an easy-to-see image. Furthermore, the subtraction image obtained in this manner does not require image level adjustment, and operability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the X-ray fluoroscopy apparatus according to the present invention, FIG. 2 is a block diagram showing the internal configuration of the light emission control circuit, and FIG. 3 is a timing diagram showing the operation of the light emission control circuit. FIG. 4 is a timing diagram showing the operation of the X-ray fluoroscopic imaging device of the present invention, FIG. 5 is a flowchart showing the procedure for emitting X-rays from the X-ray generator and emitting light from the light emitter, and FIG. 6 FIG. 1 is a block diagram showing a conventional X-ray fluoroscopic imaging device. FIG. 7 is a timing diagram showing the operation. 1... X-ray generator ゛4... Image intensifier (1, I) 5...
- Television camera 6... Image processing unit 7... Television monitor 8... Optical system 9... Subject 11... Light emitter 12... Light emission control circuit

Claims (1)

[Claims] An X-ray generator, an image intensifier that receives the X-rays emitted from the X-ray generator and transmitted through the subject, a television camera that receives the light from the image intensifier and converts it into a video signal, and In an X-ray fluoroscopic imaging apparatus having an image processing section that inputs an output signal of a television camera and performs image processing, and a television monitor that displays an image processed by the image processing section, the image intensifier and the television camera are connected to each other. A light emitting body is disposed between the two, and a light emission control circuit is provided to cause the light emitting body to emit light in a pulsed manner when the X-ray emission interval from the X-ray generating device is long and in synchronization with the timing when the X-ray emission interval is short. An X-ray fluoroscopic imaging device characterized by: