JPH0221597A - X-ray device - Google Patents

Abstract

PURPOSE:To uniformalize exposing amount properly by storing a time from the start time of X-ray radiation to the sending-out time of X-ray blocking requiring signal by means of a phototimer circuit, deciding the following blocking timing of X-ray radiation according to this measurement time value, and sending the X-ray blocking requiring signal out to an X-ray timer. CONSTITUTION:There are provided an X-ray radiation timer circuit 12 between a phototimer circuit 6 and an X-ray timer 7. This circuit 12 measures a timer from the start time of X-ray radiation by means of an X-ray tube 1 to the sending-out time of an X-ray blocking requiring signal S2 by means of the circuit 6 and stores this time, and further, sending the X-ray blocking requiring signal out to the timer 7 while deciding the blocking timing after that time according to this measurement time value. The circuit 12, also, have a counter circuit 13, count setter 14, integrator 15, sample hold circuit 16 and comparator 17. With the arrangement, an X-ray radiation time capable of giving a proper exposing amount to an X-ray film by means of the circuit 6 in the case of the photographing at the initial stage in a series of continuous photographing is decided and it is possible to radiate X-ray thereafter onto a body 3 to be inspected at the decided X-ray radiation time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an x-ray display device that irradiates a subject with X-rays and continuously captures images of the examined region on an X-ray film, and particularly relates to The present invention relates to an X-ray apparatus that can provide an appropriate and uniform exposure amount during continuous imaging in examinations and the like.

[Conventional technology]

Conventionally, in circulatory system examinations using Xl1A equipment, a contrast medium is injected into the subject's blood vessels and the process of the flow of the contrast medium is recorded on film as a means of photographing images of blood vessels inside the body on X-ray film. A so-called continuous imaging technique is used in which X-ray films are sequentially exchanged and set at an imaging position using a continuous imaging device such as a changer at a rate of, for example, 1 to 6 films per second, and X-ray imaging is performed repeatedly. At this time, the X-ray conditions consisting of the x#I tube voltage and the X-ray tube current/time product to obtain the optimal photographic exposure amount vary depending on the patient and the area to be examined, but the adjustment of the X-ray conditions is as follows: Much of this work relied on the experience and intuition of the radiology technicians operating the X-ray equipment.

Therefore, conventionally, in order to automatically obtain the optimal photographic exposure amount, a light receiving section was provided in front of the film changer to detect the amount of X-rays that passed through the subject. A phototimer system has come into use, in which a phototimer circuit shuts off X-ray irradiation when the signal reaches a predetermined reference value. That is, as shown in FIG. 3, the conventional X-ray apparatus of this type irradiates X-rays q! 1, a high voltage generator 2 that supplies high voltage to the X-ray tube 1, a film changer 4 disposed opposite to the X-ray tube 1 with the subject 3 in between, and the front surface of the film changer 4. a photo-receiving section 5, which is provided in the sensor and detects the amount of X-rays transmitted through the subject 3; and a phototimer circuit, which sends out an X-ray cutoff request signal S2 when the detection signal from the light-receiving section 5 reaches a predetermined value. 6 and the X-ray irradiation request signal S from the film changer 4, and is stopped by the X-ray cutoff request signal S from the photo timer circuit 6, and sends the X-ray irradiation signal S to the high voltage generator 2. It also included an X-ray timer 7 for sending out X-rays.

In FIG. 3, reference numeral 8 is a bed on which the subject 3 is placed, reference numeral 9 is a timer setting device for arbitrarily setting the operating time width of the X-ray timer 7, and reference numeral 10 is a request for X-ray irradiation from the film changer 4. A timer trigger circuit that receives the signal S□ and sends a trigger signal S4 to the X-ray timer 7, the code 11 is X
This is a high voltage control circuit that inputs an X-ray irradiation signal S output from a ray timer 7 and performs control to irradiate X-rays from an X-ray tube 1 via a high voltage generator 2. [Problems to be Solved] However, in such conventional X-ray apparatuses, the phototimer circuit 6 operates each time each X-ray film is taken in a series of continuous imaging, so that the continuous blood vessel images are When the contrast medium reaches the region of interest in the examination area during imaging, that is, the blood vessel portion corresponding to the light field (hole with a diameter of approximately 5Q11) drilled at a predetermined location of the light receiving section 5, the contrast medium filled in the blood vessel portion is in a state of blocking the X-rays passing through the lighting field, so that the transmitted x, in which enters the light receiving section 5
decreased, and the time required to reach the reference value indicating the optimal photographic exposure amount preset in the photo timer circuit 6 became progressively longer than at the time of photographing. Therefore, the timing of the eight X-ray cutoff request signals outputted from the phototimer circuit 6 is gradually delayed, and the cutoff of the X-ray irradiation signal S from the X-ray timer 7 is also delayed. x from
There was a delay in stopping NfA irradiation. From this, the X-ray tube current/time product increases, and as a result,
This resulted in overexposed photographs of the entire line film. In other words, in continuous imaging of blood vessel images, when several images are taken in succession with the film changer 4, at first images with appropriate exposure and appropriate density can be obtained, but 1
As time passes, as the blood vessel portion corresponding to the light receiving field of the light receiving section 5 becomes filled with contrast medium, one light becomes too many, and the base density of the entire X-ray film gradually becomes darker. Therefore, when observing and interpreting multiple X-ray photographs taken consecutively in this way, the base density of the entire X-ray film changes sequentially, making it difficult to see the photographs and making diagnosis difficult. there were.

On the other hand, in order to prevent overexposed photographs as described above, it is assumed that the contrast medium will reach the part of the light receiving section 5 that corresponds to the light field, and the optimal photographic exposure amount should be set at that time. A method may be considered in which the reference value to be given is preset in the photo timer circuit 6, but in this case, the entire X-ray film is underexposed in the photograph taken before the contrast medium reaches the part corresponding to the above-mentioned lighting field. It turned out to be. Therefore, it became difficult to see the photograph and to make a diagnosis.

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

[Means to solve the problem]

In order to achieve the above object, the X-ray apparatus according to the present invention includes:
An X-ray tube that irradiates X-rays, a high-voltage generator that supplies high voltage to the X-ray tube, a film changer that is disposed opposite to the X-ray tube with a subject in between, and the film changer. 1) A light receiving section provided on the first surface to detect the amount of X-rays transmitted through the subject, and a phototimer circuit that sends an X-ray cutoff request signal when the detection signal from the light receiving section reaches a predetermined reference value. , operates in response to an X-ray irradiation request signal from the film changer, stops in response to an X-ray cutoff request signal from the phototimer circuit, and outputs
In an X-ray device equipped with an X-ray timer that sends a radiation irradiation signal, the
The time until the transmission of the line cutoff request signal is measured, this time is memorized, and the subsequent X
An X-ray irradiation timer circuit is provided which determines the time to cut off ray irradiation and sends an X-ray cutoff request No. 1 to the X-ray timer.

[For production]

The X-ray apparatus configured in this manner uses an xl irradiation timer circuit to control the
A device that measures the time until the sending of the ray cutoff request signal, stores this time, determines the time to cut off the subsequent X-ray irradiation based on this measured time value, and sends the X-ray cutoff request signal to the X-ray timer. It is. As a result, the phototimer circuit determines the X-ray irradiation time that can give the appropriate exposure amount to the X-ray film at the first time in a series of continuous imaging, and thereafter, the X-ray irradiation time determined above is used to expose the subject to X-rays. It works to irradiate. As a result, the amount of exposure to the X-ray film during continuous imaging in, for example, circulatory system examinations can be made appropriate and uniform.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to 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 irradiates the subject with X-rays and continuously captures images of the examined area on X-ray film. , a film changer 4 , a light receiving section 5 , a phototimer circuit 6 , and an X-ray timer 7 .

The X-ray tube 1 irradiates the subject 3 with X-rays. The high voltage generator 2 is connected to the upper v! , which supplies high voltage to the X-ray tube 1. The film changer 4 sequentially sets X-ray films at the imaging position at a speed of about 1 to 6 films per second and stores the film after imaging, and is opposed to the X-ray tube 1 with the subject 3 in between. When the X-ray film is set at the imaging position,
A line irradiation request signal S1 is sent. The light receiving section 5 detects the X-rays that have passed through the subject 3 and the bed 8 on which it is placed. A lighting field consisting of a hole with a diameter of, for example, about 5 marks is formed at the location. The photo timer circuit 6 is connected to the light receiving section 5.
When the transmitted X-ray signal detected by XuA reaches a predetermined reference value indicating the optimal photographic exposure,
It sends out a cutoff request signal S2. X-ray timer 7
is operated by the X-ray irradiation request signal S□ sent from the film changer 4, and is stopped by the X-ray cut-off request signal S2 sent from the phototimer circuit 6, so that the high voltage generator 2 is not irradiated with X-rays. It sends out a signal S. In FIG. 1, reference numeral 8 indicates a bed on which the subject 3 is placed, reference numeral 9 indicates a timer setting device for arbitrarily setting the operating time width of the X-ray timer 7, and reference numeral 10 indicates an X-ray irradiation request from the film changer 4. A timer trigger circuit, reference numeral 11, receives the signal S0 and sends a trigger signal S4 to the X-ray timer 7.
is a high voltage control circuit which inputs the X-ray irradiation signal S outputted from the X-ray timer 7 and performs control to irradiate X@ from the X-ray 91 via the high voltage generator 2.

In the present invention, an X-ray irradiation timer circuit 12 is provided between the phototimer circuit 6 and the X-ray timer 7. This X-ray irradiation timer circuit 12 measures the time from the start of X-ray irradiation by the It determines the time to cut off subsequent X-ray irradiation based on the value and sends an X-ray cutoff request signal to the X-ray timer 7.
6 and a comparator 17.

The counter circuit 13 is operated by the X-ray timer 7.
Count the number of times of the line irradiation signal S, and set the count setting device 1.
4, a predetermined signal is sent out when the number of times arbitrarily set in advance is reached, and its contents are reset to the initial state by short-circuiting the switch 18. The integrator 15 receives the X transmitted by the operation of the X-ray timer 7.
The line irradiation signal S is inputted and integrated at a rate determined by the voltage dividing resistor 19.20 and the integrating capacitor 21. The sample and hold circuit 16 samples and holds the output of the integrator 15 at a timing related to the outputs of the phototimer circuit 6 and the counter circuit 13. The comparator 17 uses the output of the sample and hold circuit 16 as a reference, and sends out an X-ray cutoff request signal S5 when the value of the output of the integrator 15 becomes equal to this reference value. Note that the counter circuit 1
3, the sample hold circuit 16, and the X-ray timer 7 are connected by a predetermined logic circuit.

Next, regarding the operation of the X-ray apparatus configured in this way,
This will be explained with reference to the timing diagram shown in FIG. First, when performing a series of continuous imaging, the timer setting device 9 operates the X-ray timer 7, the photo timer circuit 6 operates the
Set the X-ray irradiation time to be sufficiently longer than the time expected to be blocked by pre-irradiation. This is because the X-ray irradiation time that can be irradiated is determined by the constraints that the film changer 4 must change, for example, 1 to 6 X14 films per second, so it can be determined within that range, and the photo timer This setting is made in order to prevent overloading the X-ray tube 1 due to continued X-ray irradiation when the circuit 6 does not operate for some reason, and to prevent unnecessary exposure to radiation.

Next, the counter circuit 13 is set by the count setter 14.
It is determined how many X-rays are to be irradiated from the beginning in a series of continuous photographing to which the phototimer circuit 6 is to be operated. That is, in the counter circuit 13, when a numerical value n (n=1°2.3...) is set by the count setting device 14, X is output from the F terminal of the counter circuit 13 to the input terminal.
When the X-ray irradiation signal S3 is input 0 times from the X-ray timer 7, the count completion signal S6 is output, and from the E terminal, when the X-ray irradiation signal S is inputted (n+1) times to the above input terminal, another signal is output. A count completion signal S7 is output. below,
To simplify the explanation, it is assumed that the count setter 14 sets the numerical value II II I+ in the counter circuit 13. At this time, when the X-ray irradiation signal S is input once to the input terminal of the counter circuit 13, the count completion signal S is output from the F terminal, and the X-ray irradiation signal S3 is input twice to the input terminal. Then, another count completion signal S7 is output from the E terminal.

First, start continuous shooting from this state.

Switch 18 is opened. As a result, the terminal G that sets the counter circuit 13 to the initial state is opened.

The counter circuit 13 becomes ready for counting.

Next, when the X-ray film is set at the imaging position inside the film changer 4 and becomes ready for X-ray irradiation, an X-ray irradiation request signal S□ is sent from the film changer 4 to the timer trigger circuit 10. be done. Then, the timer trigger circuit 10 sends out a trigger signal S4 to the X-ray timer 7 at the timing (i) as shown in FIG. 2(a). At the same time, the X-ray timer 7 inputs the trigger signal S4 to the A terminal and outputs the signal from the B terminal as shown in FIG.
As shown in b), at the timing of (i), the X-ray irradiation signal S
, outputs. Here, the electronic switch 22 of the integrator 15 is opened only during the period when the X-ray irradiation signal S3 is outputted from the X-ray timer 7, and the integrator 15 operates as shown in FIG.
) outputs an integral output S, as shown in FIG. At the same time, during the period in which the X-ray irradiation signal S3 is output, the high voltage control circuit 11 and the high voltage generator 2 irradiate X-rays from the X-ray tube 1, and the irradiated X-rays are transmitted to the subject. 3 and the bed 8 to reach the light receiving section 5 and the film changer 4,
The X-ray film in the film changer 4 is exposed. Further, the light receiving section 5 detects the transmitted X-ray scene and sends a detection signal S having a value corresponding to the exposure amount of the film to the phototimer circuit 6.

Thereafter, when the X-ray irradiation from the X-ray tube 1 continues and the detection signal S inputted from the light receiving section 5 becomes equal to the reference value of the appropriate exposure amount set in advance in the phototimer circuit 6, the phototimer circuit From 6 onwards.

As shown in FIG. 2(c), the X-ray cutoff request signal S2 is sent out at the timing (ii). Here, as mentioned above, if II II II is set in the counter circuit 13, by inputting the X-ray irradiation signal S from the X-ray timer 7 once to the input terminal of the counter circuit 13, , the count completion signal S6 is output from the F terminal of the counter circuit 13 at the timing (i) as shown in FIG. 2(d).
is output, but no other count completion signal S7 is sent from the E terminal yet. At this time, the X-ray cutoff request signal S2 sent from the phototimer circuit 6 is
In addition to manually inputting the ND circuit 23a, the third AND circuit 2
3c, and the signal from the E terminal of the counter circuit 13 is inverted by the inverter 24 and input to the other input terminal of the third AND circuit 23c. Therefore, the third AND circuit 23c ANDs the two input signals, opens the gate, and allows the signal to pass through. This third AN
The output signal from the D circuit 23c is sent to the fifth AND circuit 23.
to the reset terminal C of the X-ray timer 7 via e.

As shown in FIG. 2(j), the timer reset signal S□ is generated at the timing (if). Close and input. This results in
As shown in FIG. 2(b), the X-ray irradiation signal S3 from the B terminal of the X-ray timer 7 is cut off at the timing (n), and the
X-ray irradiation from the ray tube 1 is stopped. That is, as a result, the X-ray irradiation is stopped by the X-ray cutoff request signal S2 sent from the phototimer circuit 6.

At this time, as described above, since the count completion signal s6 is output from the F terminal of the counter circuit 13, the first AND circuit 23a outputs the count completion signal S and the X-ray cutoff request signal s2. The gate is opened by ANDing, and the signal passes through. Then, this first AND circuit 23
The output signal from a is passed through the second AND circuit 23b by ANDing the signal from the inverter 24 and opening the gate, as shown in FIG. 2(f).
At this timing, the sampling signal S is input to the sample and hold circuit 16, and at this timing, the value of the integral output S from the integrator 15 is sampled and held. As a result, the time from the start of X-ray irradiation to the sending of the X-ray cutoff request signal S2 by the phototimer circuit 6 is measured, and this time is stored in the sample and hold circuit 16. The sampling output S 12 held in the sample hold circuit 16 and outputted at the timing (ii) as shown in FIG.
This value is input to one input terminal of 7 and becomes the basic value for transmitting the subsequent X-ray cutoff request signal. Next, as shown in FIG. 2(b), at the timing (i) when the X-ray irradiation signal S is cut off, the electronic switch 22 of the integrator 15 becomes short-circuited.
The integrating capacitor 21 is discharged, and as shown in FIG.
), the integral output S8 is returned to the initial state in preparation for the first X-ray irradiation. The electronic switch 22 has a time delay element, and the sample hold circuit 16 prevents a short circuit from occurring during sampling.

Next, the exposure amount film is stored inside the film changer 4, and when the next X-ray film is set in a state ready for imaging, the second X-ray irradiation process is started. That is, the X-ray irradiation request signal S1 from the film changer 4
is sent to the timer trigger circuit 10, and the timer trigger circuit 10 sends out a trigger signal S4 at the timing (iii) as shown in FIG. As shown in (b), (iii
), the second X-ray irradiation signal S3 is output. Here, the difference from the first X-ray irradiation is 2.
Since the X-ray irradiation signal S is inputted to the input terminal of the counter circuit 13, the other signals 1 to S7 are output from the E terminal at the timing (in) as shown in FIG. 2(e). is output, and this signal S7 is inverted by the inverter 24 and inputted to the other input terminals of the second and third AND circuits 23b and 23c.
3b.

23c is closed. Therefore, the X-ray cutoff request signal S2 output from the phototimer circuit 6
is connected to the second AND circuit 2 via the first AND circuit 23a.
3b, the second AND circuit 23b outputs the sampling signal S to the sample hold circuit 16.
It will not be output to. Furthermore, even if the X-ray cutoff request signal S2 is manually input to the third AND circuit 23c, the gate of the third AND circuit 23c is closed, so the X-ray cutoff request signal S2 is transmitted through the fifth AND circuit 23e. The request signal S2 is a timer reset signal S. As such, it is never input to the reset terminal C of the X-ray timer 7. Therefore, the X-ray cutoff request signal S2 from the phototimer circuit 6 has no effect.

In this state, the integrator 15 inputs and integrates the X-ray irradiation signal S sent out from the X-ray timer 7, and outputs an integral output S as shown in FIG. 2(g).

Then, this integral output Ss is inputted to the other input terminal of the comparator 17, and is held in the sample hold circuit 16 as a reference value corresponding to the time when the X-rays are cut off by the first phototimer circuit 6. When it becomes equal to this reference value, the comparator 17 outputs the X-ray cutoff request signal S at the timing (iv) as shown in FIG. 2(i).

The X-ray cutoff request signal S from this comparator 17 is.

As shown in FIG. 2(j), the timer reset signal S1. Close and input. As a result, as shown in FIG. 2(b), the X-ray irradiation signal S3 from the X-ray timer 7 is cut off at the timing (iv), and the X-ray irradiation from the X-ray tube 1 is stopped. As a result, in the second X-ray irradiation, the phototimer circuit 6 is not used, and the X-rays are irradiated for the same time as the X-ray irradiation time when the phototimer circuit 6 is used in the first X-ray irradiation. This means that it has been irradiated.

Thereafter, from the third X-ray irradiation until the end of the series of continuous imaging, the same operation as in the second X-ray irradiation is repeated and X-rays are irradiated for the same time as the irradiation time in the 51st X-ray irradiation. As a result, all X
The exposure amount of the line film can be made appropriate and uniform.

In addition, although FIG. 1 shows that the number of times of the X-ray irradiation signal S3 by the operation of the X-ray timer 7 is arbitrarily set by the count setting device 14 in the counter circuit 13, the present invention is not limited to this. The time from the start of imaging in a series of continuous imaging may be arbitrarily set, and the determination of the X-ray irradiation time using the photo timer circuit 6 may be divided by the time from the start of imaging.

〔Effect of the invention〕

Since the present invention is configured as described above, the photo timer circuit 6 determines the X-ray irradiation time to give an appropriate exposure amount to the X-ray film at the first shooting in a series of continuous shooting, and thereafter the above-determined X-rays on object 3 during X-ray irradiation time
rays can be irradiated. As a result 1, for example, the amount of exposure to an X-ray film during continuous imaging in circulatory system examinations can be made appropriate and uniform. Therefore, for example, in continuous imaging of blood vessel images, the film changer 4
When taking several pictures in succession, at first you can obtain pictures with the proper exposure and proper density, but as time passes, the contrast medium is deposited in the blood vessels corresponding to the light field of the light receiving section 5. It is possible to eliminate the conventional problem that the base density of the entire X-ray film gradually becomes darker due to overexposure due to the filling. From this, when observing and interpreting multiple X-ray photographs taken consecutively as described above, the base Δ] degree of the entire X-ray film does not change sequentially but remains approximately constant. The photograph becomes easier to see and diagnosis can be made easier.

[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 timing chart for explaining its operation, and FIG. 3 is a block diagram showing a conventional X-ray apparatus. DESCRIPTION OF SYMBOLS 1... X-ray tube, 2... High voltage generator, 3... Subject, 4... Film changer, 5... Light receiving part, 6... Photo timer circuit, 7... X-ray Timer, 8... Bed, 9... Timer setting device, 1
0...Timer trigger circuit, 11...High voltage control circuit, 12...X-ray irradiation timer circuit.

Claims (1)

[Claims] An X-ray tube that irradiates X-rays, a high-voltage generator that supplies high voltage to the X-ray tube, a film changer that is disposed opposite to the X-ray tube with a subject in between, and the film changer. a light receiving section provided on the front surface for detecting the amount of transmitted X-rays of the subject; a phototimer circuit that sends an X-ray cutoff request signal when the detection signal from the light receiving section reaches a predetermined reference value; and the film changer. In an X-ray apparatus having an The time from the start of irradiation to the sending of the X-ray cut-off request signal by the phototimer circuit is measured, and this time is memorized, and the time to cut off subsequent X-ray irradiation is determined based on this measured time value, and the X-ray cut-off request is made. An X-ray device comprising an X-ray irradiation timer circuit that sends a signal to an X-ray timer.