JPH01276596A - X-ray device - Google Patents

Abstract

PURPOSE:To unify the photographic density of a photographing film by calculating the exposure quantity of each photographing continued in sequence with a calculating means and controlling the exposure quantity of each photographing at the preset ratio based on the calculated result. CONSTITUTION:A correction data setting means 14 is connected to a logical operation element 9, an elapse timer 15 is connected as a counting means, the correction data setting means 14 optionally sets the correction ratio data to correct the exposure quantity in response to the elapsed time of photographing. The logical operation element 9 calculates the correction ratio value using the elapsed time read out by the elapse timer 15 and the correction ratio data stored in a RAM 10 prior to the start of the first photographing and adds the next correction to the timer value of the first photographing and corrects and calculates the timer value of the second photographing. A photographing film with nearly fixed blackening density can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray apparatus for, for example, circulatory organ examinations, which injects a contrast medium into the blood vessels of a subject and continuously takes images.

In particular, the present invention relates to an X-ray apparatus that can change the exposure amount of each successive radiograph at a predetermined rate according to the elapsed time in a series of radiographs.

[Conventional technology]

As shown in FIG. 4, a conventional X-ray apparatus of this type includes a power supply 1, an autotransformer 2 for setting the X-ray tube voltage, and a timer circuit 6 for controlling the imaging time, which will be described later. An X-ray irradiation switch 3 is driven for a predetermined time by a timer signal t from the X-ray irradiation switch 3, and by driving this X-ray irradiation switch 3, the voltage supplied from the autotransformer 2 is boosted by a high voltage converter 4a and a rectifier 4b. a high voltage generating means 4 that generates a high voltage by rectifying the high voltage; an X-ray tube 5 that emits X-rays by applying a high voltage from the high voltage generating means 4; a timer circuit 6 that outputs a timer circuit 6, a film changer 7 that sets films one after another in the shooting position for continuous shooting and sends a timer drive signal d to the timer circuit 6;
The device was comprised of an injector 8 that injects a contrast agent into a subject (not shown) in response to a start signal S from a start signal S, and a logical operation element 9 such as a microprocessor that controls each of the above-mentioned components. In FIG. 4, 10 is a RAM (random write/read memory) that stores timer values, etc., and 11 is a ROM (read-only memory).
2 is a photographing start switch operated by the operator 13. Further, inside the high voltage generating means 4, a heating transformer 4C for adjusting the tube current of the X-ray tube 5 is provided. Then, the autotransformer 2 adjusts the tube voltage applied to the X-ray tube 5, or the tube current adjusting heating transformer 4C adjusts the tube current supplied to the X-ray tube 5, or the timer circuit 6 By adjusting the shooting time, you can control the amount of exposure.

Next, the operation of such a conventional device will be explained. Once the imaging conditions are set using known means and methods (not shown),
The brush 2' of the autotransformer 2 is set at a predetermined position by a command from the logic operation element 9, while the heating transformer 4c for adjusting the tube current in the high-voltage E generating means 4 is heated to a predetermined tube current. A voltage is output, and a timer value of the photographing time is stored in RAM10. In this state, when the operator 13 operates the shooting start switch 12, the timer value stored in the RAM 10 is read out and set in the timer circuit 6.1 Next, all conditions for shooting are complete. When this occurs, the timer drive signal d is sent from the film changer 7 to the timer circuit 6, and the timer circuit 6 outputs a timer signal t for controlling the photographing time. This timer signal t is input to the X-ray irradiation switch 3, which drives the X-ray irradiation switch 3, and applies a high voltage to the X-ray tube 5 via the high voltage generation means 4, and the X-ray irradiation switch 3 is driven. X-rays are emitted from the tube 5. Simultaneously with the timer drive signal d, the film changer 7 sends a start signal S to the injector 8, whereby the injector 8 starts operating.

A contrast agent is injected into the subject. Here, the timer drive signal d output from the film changer 7 is generated multiple times at a predetermined timing, and in synchronization with this, the timer circuit 6 operates multiple times to sequentially output the timer signal t.
By driving the ray irradiation switch 3 multiple times, the X-ray tube 5
X-rays are emitted multiple times, and as a result, blood vessel images of the imaged region of the subject are continuously imaged. Note that the timer signal t output from the timer circuit 6 is also input to the logic operation element 9 and monitored, so that the logic operation element 9 can grasp the status of X-ray irradiation. The procedure for such a photographing operation is shown in the flowchart of FIG.

[Problem to be solved by the invention]

However, in such conventional X-ray apparatuses, exposure amounts such as X-ray tube voltage, X-ray tube current, and imaging time remain constant in a series of successive imagings. In other words, there is no operation to change the exposure amount for each shot in a series of shooting operations, and the exposure amount set for the first shot (in this case (photographing time indicated by the timer value set in the timer circuit 6) until the final photographing. However, depending on the elapsed time of a series of imaging, the contrast agent injected into the subject may not be sufficiently distributed over the imaging area.
When the contrast agent reaches the capillaries, the area to be imaged becomes filled with the contrast agent, which increases the absorption of X-rays and reduces the amount of X-rays transmitted through the area.
The dose will be lower.

On the other hand, since the exposure amount is kept constant as described above, the degree of blackening of the photographic film becomes insufficient depending on the elapsed time. This lack of darkening on the photographic film results in X-ray photographs with low diagnostic value.
There is a risk that important lesions at the diagnostic site may be overlooked, and the clinical value of the Xi device may be reduced.

Therefore, one object of the present invention is to provide an X-ray apparatus 6 that can solve such problems.

[Means to solve the problem]

The above purpose is to provide means for controlling the exposure amount such as X-ray tube voltage, X-ray tube current, and imaging time, and to perform X-ray irradiation that is driven for a predetermined time by a timer signal from a timer circuit for controlling the imaging time. A switch, a means for boosting and rectifying the voltage supplied from the power supply to generate a high voltage by driving the X-ray irradiation switch, and an A correction ratio for correcting the amount of exposure according to the elapsed time of imaging in an X-ray apparatus that is equipped with a ray tube and a calculation means for controlling each of the above components, and injects a contrast agent into a subject and performs continuous imaging. A correction data setting means for setting data and a clock means for measuring the elapsed time from the injection of contrast medium in a series of imaging are provided, and the correction data setting means sets the data according to the elapsed time measured by the time measurement means. The exposure amount for each consecutive shooting is determined by the means for controlling the exposure amount based on the calculation result from the calculation means. This is accomplished by an X-ray machine with rate control.

[For production]

In the X-ray apparatus configured in this way, the correction data setting means sets correction ratio data for correcting the exposure amount according to the elapsed time of imaging, and the timer measures the correction ratio data for correcting the exposure amount in a series of imagings. The elapsed time is measured, and the calculation means takes in the correction ratio data set by the correction data setting means according to the elapsed time measured by the time measurement means, and sequentially calculates the exposure amount for each consecutive shooting. The exposure amount for each photographing is controlled at a predetermined ratio by means for controlling the exposure amount based on the calculation result from the calculation means.

〔Example〕

Hereinafter, five embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an X-ray apparatus according to the present invention. This X-ray device injects a contrast medium into the blood vessels of the subject and performs continuous imaging. winding transformer 2, X-ray irradiation switch 3, high voltage generation means 4, X-ray tube 5, timer circuit 6, film changer 7, injector 8, logic operation element 9
It is made up of the following.

The autotransformer 2 takes in voltage from the power supply 1 and sets the X-ray tube voltage, and is controlled according to the tube voltage set by known means and methods (not shown). . The X-ray irradiation switch 3 is configured to send the output voltage from the autotransformer 2 to the high voltage generation means 4 by inputting a timer signal t output from a timer circuit 6 to be described later and driving it for a predetermined time. It has become. High voltage generation means 4
teeth.

It generates a high voltage by boosting and rectifying the voltage supplied from the autotransformer 2 by driving the X-ray irradiation switch 3, and contains a high voltage transformer 4a, a rectifier 4b, and a tube current adjustment device. It has a heating transformer 4C. The X-ray tube 5 receives a high voltage from the high voltage generating means 4 and emits X-rays. The timer circuit 6 sends a timer signal t to the X-ray irradiation switch 3 for controlling the imaging time. Also, the film changer 7.

The film is set one after another in the shooting position for continuous shooting, and a timer drive signal d is sent to the timer circuit 6. Further, the injector 8 receives the start signal S output from the film changer 7 and injects the contrast medium into the subject. The logic operation element 9 serves as an operation means for controlling each of the above-mentioned components, and is composed of, for example, a microprocessor. Note that in FIG.
M (anytime write/read memory), code 11 is ROM
(read-only memory), and reference numeral 12 is a photographing start switch operated by an operator 13. Then, the autotransformer 2 adjusts the tube voltage applied to the X-ray tube 5, the tube current adjustment heating transformer 4c adjusts the tube current supplied to the X-ray tube 5, or the timer circuit 6 adjusts the tube voltage applied to the X-ray tube 5. By adjusting the shooting time, the amount of exposure for shooting is controlled.

Here, in the present invention, a correction data setting means 14 is connected to the logic operation element 9, and an elapse timer 15 as a time measuring means is also connected. The correction data setting means 14 sets the exposure amount (first
This is used to arbitrarily set the correction ratio data for correcting the shooting time (in the figure). Time data setting switch 1
6, a correction ratio data setting switch 17, and, for example, three registration switches 18a, 18b, and 18c.

The time data setting switch 16 is used to set elapsed time data from the start of shooting in a series of shootings, for example, the time T-='I'z- on the horizontal axis in the graph of FIG.
Ta can be set arbitrarily. The correction ratio data setting switch 17 is the same as the time data setting switch 1.
This is to set the correction ratio data (% value) of the shooting time to the timer value of the first shooting according to the elapsed time from the start of shooting set in step 6.1 For example, the correction of the vertical axis in the graph of Fig. 2 Proportion COMP work, COMP2.
COMP can be set arbitrarily. Registration switch 18a.

18b and 18c register combinations of data for correcting the photographing time set by the time data setting switch 16 and the correction ratio data setting switch 17, respectively, in the logical operation element 9; 1, for example, the first registration switch; 18a registers the combination of time T2 and correction ratio COMP in the graph of FIG. 2, second registration switch 18b registers the combination of time T2 and correction ratio COMP, and third registration switch 18c registers the time A combination of T3 and correction ratio COMP is registered. The time data setting switch 16 and the correction ratio data setting switch 17 are, for example, 8-bit command switches, and the first to third registration switches 1
8a to 18c are ordinary key switches and the like. Further, the elapsed timer 15 measures the elapsed time from the injection of the contrast medium into the subject in a series of imaging.

Note that a switch circuit 19 is provided between the timer circuit 6 and the film changer 7.

This switch circuit 19 blocks or releases the timer drive signal d outputted from the film changer 7 from being sent to the timer circuit 6, and is turned on or off by a command from the logic operation element 9. ing. Further, the timer drive signal d output from the film changer 7 is input to the logic operation element 9 and monitored.

Next, regarding the operation of the X-ray apparatus configured in this way,
This will be explained with reference to the flowchart shown in FIG. First, prior to a series of imaging, the operator 13 takes into account the blood circulation state of the subject (patient) to be imaged and determines the elapsed time of imaging as shown in FIG. For example, if the elapsed time T1 after injection of the contrast medium in FIG. The correction ratio COMPi of the imaging time with respect to the timer value of the first imaging is set using the correction ratio data setting switch 17, and the first registration switch 18a is pressed. Then, the logical operator 9 reads the respective data of the setting switches 16 and 17 and stores them in the RAM 10 using a known method. Similarly, the elapsed time T after contrast medium injection and the correction ratio COMP2 of the imaging time with respect to the first timer value at the elapsed time T2 are set using the time data setting switch 16 and the correction ratio data setting switch, respectively. 17, set the second 'JIB switch L
Press 8b to store it in RAM10.

Furthermore, in the same way, the elapsed time T after contrast medium injection.

and the correction ratio GOMP of the shooting time with respect to the first timer value at the time of this elapsed time T, respectively, are set with the time data setting switch 16 and the correction ratio data setting switch 17, and the third registration switch 18c is set. Press
Store in RAM10. As shown in FIG. 2, the three sets of correction ratio data stored in this way are handled by the logical operation element 9 as a correction curve of the timer value of each shooting with respect to the elapsed time of a series of shootings.

As described above, after the correction ratio data of the imaging time with respect to the timer value for the first imaging at the start of imaging is input, the operator 13 operates the imaging start switch 12 for actual imaging. Then, in the same way as the conventional device, the RAM
The timer value for the first photographing, which is stored in l0 in advance, is read out and set in the timer circuit 6 (step A in FIG. 3).

Also, to measure the elapsed time of a series of shots.

The elapsed timer 15 is set to a standby state by a command from the logic operator 9 (step B), and when all the conditions for the first shooting are in the Q ready state, the film changer 7 A timer drive signal d is sent to the switch circuit 19, and a start signal S is sent to the injector 8, and upon input of this start signal S, the injector 8 is operated and a contrast medium is injected into the subject. At this time, the logic operation element 9 monitors the generation of the timer drive signal d from the film changer 7, and when it recognizes the timer drive signal d, it turns on the switch circuit 19 and unblocks the timer drive signal d. (Step C). At the same time, the elapsed timer 15 is started to count the elapsed time since the injection of the contrast medium.

By turning on the switch circuit 19, the timer drive signal d is input to the timer circuit 6, and the timer circuit 6 operates to turn on the timer signal t ("YE" in step D).
Then, this timer signal t is input to the X-ray irradiation switch 3, and the X-ray irradiation switch 3 is driven to emit X-rays from the X-ray tube 5, resulting in the first imaging.

Thereafter, the timer circuit 6 turns off the timer signal t according to the elapse of the photographing time as the contents of the timer value set in the step A ("Y E S" in step E).
” side). Then, due to the disappearance of the timer signal t,
The radiation irradiation switch 3 is shut off, X-ray radiation from the X-ray tube 5 is stopped, and the first imaging is completed. At this time, the logical operation element 9 monitors the timer signal t,
When the end of the first photographing is recognized by the disappearance of the timer signal t, the switch circuit 19 is turned off and the timer drive signal d is blocked (step F).

The timer drive signal d is turned off each time one shooting is completed, and turned on again when the film changer 7 is ready for the next shooting.

In this state, the logical operation element 9 starts monitoring the timer drive signal d again in order to know when the second photographing has started. When all the conditions for the second shooting are ready, the timer drive signal d is sent from the film changer 7 to the switch circuit 19, and the logical operation element 9 receives the second timer drive signal d. The logical operation element 9 then reads out the elapsed time from the injection of the contrast medium to the present from the elapsed timer 15 (step H).
At this time, the elapsed timer 15 continues to count the time even after the elapsed time value is read out.

Next, the logical operation element 9 calculates the elapsed time read from the elapsed timer 15 and the RAM l before the start of the first photographing.
Using the correction ratio data stored in 0, calculate the correction ratio value on the linear function as shown in Figure 2, add the following correction to the timer value of the first shooting, and The timer value for the first shot is corrected (step I). In other words, the timer value for the first shot is set to t, and the data for the first shot is calculated based on the pre-stored correction ratio data as shown in Figure 2. Let GOMP be the correction ratio calculated using the elapsed time from photography to the nth photography, and let tn (n=2.3, 4, . . .) be the timer value for the nth photography.

tn=t, (1+ωMP/100) (1) For example, in FIG. 2, if the elapsed time until the nth photographing is T1, the correction ratio at this time is COMP.

tn=t, (1+COMP1/100). Note that the correction ratio corresponding to the intermediate elapsed time other than the three elapsed times T, T2°T in FIG. 2 can be calculated using an interpolation method.

Next, the timer value t2 for the second photographing, which has been corrected in this way, is set in the timer circuit 6 (step J).
, At the same time, the logic operator 9 recognizes that the timer drive signal d is turned on in step G, turns on the switch circuit 19, and unblocks the timer drive signal d (step K). When the camera reaches L, it is determined whether the shooting is to be interrupted or not. Since the second shooting has just begun, step L advances to the "NO" side and enters step D.Next, by turning on the switch circuit 19, the timer drive signal d is input to the timer circuit 6. Then, the timer circuit 6 operates and turns on the timer signal t ("YES" side in step D). Then, this timer signal t is input to the X-ray irradiation switch 3, and this X-ray irradiation switch 3 X-rays are emitted from the X-ray tube 5, and the second
This will be the second shooting. Thereafter, the timer circuit 6 turns off the timer signal t when the photographing time (longer than the first photographing time) as the content of the timer value t2 set in step J has elapsed ("Y" in step E). E
S” side), then due to the disappearance of the timer signal t,
The line irradiation switch 3 is shut off.

The X-ray emission from the X-ray tube 5 is stopped, and the second imaging is completed. Since this second imaging time is longer than the first imaging time, it is possible to compensate for a decrease in the degree of blackening of the film due to the filling of the contrast medium. At this time, when the logical operation element 9 recognizes the end of the second photographing due to the disappearance of the timer signal t, it turns off the switch circuit 19 and blocks the timer drive signal d (step F).

In the same manner, step G-4H→Work→J→→L→
The procedure from DIE to F is repeated, and the third and subsequent shots are sequentially executed. At this time, the timer value tn for each shooting is corrected each time using equation (1) and set in the timer circuit 6. Therefore, even if the contrast medium becomes filled with the elapsed time of imaging, by changing the imaging time of each time at a predetermined rate, it is possible to compensate for the decrease in the degree of blackening of the film. Note that the time required to calculate a new timer value tn for each shooting is at most 2
~3 m5ec, which is not a delay time that would cause a problem in practical use.
"Y E S" in step L or step M
All you have to do is go to the side.

In addition, in FIG. 1, the correction data setting means 14 is shown as having three registration switches, but the present invention is not limited to this. Four or more may be provided depending on the number of.

In addition, in the embodiment shown in FIG. 1, the exposure time is selected as the control target for the exposure amount that is changed according to the elapsed time of imaging, but the present invention is not limited to this. In cases where high-speed tube voltage control means such as internal drop control of the tetrode tube is used to control the high voltage, the tube voltage may be changed as a target for controlling the exposure amount, or the exposure amount may be controlled by changing the tube voltage. The tube current may be changed as the amount to be controlled.

In this case, the correction ratio data setting switch 17 in FIG. 1 is used to set the correction ratio for tube voltage or tube current, and FIG. It is treated as meaning a voltage or tube current correction curve, and further steps A and I in FIG.

It is sufficient to perform the processing of J for each tube voltage or tube current.

〔Effect of the invention〕

Since the present invention is configured as described above, the exposure amount such as the X-ray tube voltage, X-ray tube current, or imaging time of each successive imaging is changed at a predetermined ratio according to the elapsed time in a series of imaging. be able to. Therefore, even if the contrast agent injected into the subject spreads over the area to be imaged and the absorption of X-rays increases and the amount of X-rays transmitted through the area changes depending on the elapsed time of a series of imaging, the amount of X-rays transmitted through the area may vary. By changing the exposure amount, it is possible to compensate for variations in the degree of darkening of the photographic film. As a result, it is possible to obtain a photographic film with a substantially constant degree of blackening, resulting in an X-ray photograph with high diagnostic value.
The clinical value of the X-ray device can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the X-ray apparatus according to the present invention, Fig. 2 is a graph showing the correction ratio of exposure amount with respect to the elapsed time of imaging set arbitrarily, and Fig. 3 is the X-ray apparatus according to the present invention. Flowcharts 1 to 4 showing the operations are block diagrams showing a conventional X-ray apparatus, and FIG. 5 is a flowchart showing the procedure of the imaging operation in the conventional apparatus. 1...Power supply, 2...Auto transformer, 3...X
Ray irradiation switch, 4... High voltage generation means, 4c
...Heating transformer for adjusting tube current, 5...Xs tube,
6...Timer circuit, 7...Film changer, 8...Injector, 9...Logic operation element (calculation means), 14...Correction data setting means, 1
5... Elapsed timer (timekeeping means), 19... Switch circuit.

Claims (1)

[Claims] means for controlling exposure amounts such as X-ray tube voltage, X-ray tube current, and imaging time; A means for generating a high voltage by boosting and rectifying the voltage supplied from a power supply by driving an X-ray irradiation switch; an X-ray tube for emitting X-rays by applying a high voltage from the high-voltage generating means; Correction that sets correction ratio data for correcting the exposure amount according to the elapsed time of imaging in an X-ray apparatus that is equipped with arithmetic means that controls each component and that injects a contrast medium into a subject and performs continuous imaging. A data setting means and a timer for measuring the elapsed time from injection of a contrast medium in a series of imaging are provided, and correction ratio data is set by the correction data setting means in accordance with the elapsed time measured by the timer. The calculation means calculates the exposure amount for each successive shooting, and the exposure amount for each shooting is controlled at a predetermined ratio by the exposure control means based on the calculation result from the calculation means. An X-ray device characterized by: