JPH0332136Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a device for recording a still image of an X-ray transmitted image, and in particular, the present invention relates to a device for recording a still image of an X-ray transmitted image, and in particular, a doctor can record a specific part of an object such as a patient while observing a transmitted X-ray image. When you want to record a still image of a specific part to observe it more closely, you can use the X
The present invention relates to a radiography device.

(Prior art) In diagnosis using an X-ray imaging device, it is necessary to take a transmitted X-ray image from a predetermined angular position of the affected area of a subject and record it as an image to confirm the disease state. It is necessary to judge the therapeutic effect and decide on the subsequent treatment policy.

For this reason, conventional methods have been to irradiate the affected area with X-rays while changing the subject's posture, display the transmitted X-ray image on an image intensifier, or to photograph it with a television camera. I try to observe it on a monitor TV.
Therefore, in order to record a still image of a specific area, conventionally, the amount of X-rays is increased and the transmitted X-rays are directly exposed to the film and recorded, or the image displayed on a TV monitor is photographed using a photo camera. Was.
However, the former method requires a strong X-ray dose, which poses safety issues for patients and examiners, while the latter method results in poor gradation and is unable to provide clear photographs. There's a problem.

(Problems to be solved by the invention) The present invention solves the drawbacks of recording a still image of any specific part of an X-ray transmitted image of a subject taken by these conventional X-ray imaging devices, and normal X-rays without increasing the amount of X-rays projected onto
It is an object of the present invention to provide an apparatus that can arbitrarily obtain a clear record of a still image of a specific part in the state of photographing a line transmission image.

(Means for Solving the Problems) In order to achieve the above object, a device for recording still images of X-ray transmitted images according to the present invention continuously captures X-ray transmitted images of a non-stationary subject, and a television camera that sends out pixel signals indicating an X-ray transmission image; a first memory that sequentially receives the pixel signals sent out from the television camera and stores one frame of the latest pixel signals; The stored pixel signals for one frame are transferred to a predetermined first
pixel signal readout means for sequentially reading out one line at a time in synchronization with a clock signal; and receiving the pixel signal read out by the pixel signal readout means;
means for visually displaying the X-ray transmission image indicated by the pixel signal; and means for stopping the transmission of the pixel signal from the television camera to display the pixel signal stored in the first memory. a means for fixing the fixed pixel signals stored in the first memory, one line at a time, in synchronization with a second clock signal having a period corresponding to at least one frame of the pixel signals; and means for storing a still image corresponding to the fixed pixel signal in a predetermined recording medium based on the pixel signal stored in the second memory.

(Function) Since the present invention is constructed as described above, the image signal from the television camera showing the X-ray transmission image of the subject is stored in the first memory one frame at a time, and
The stored pixel signals are sequentially read out one line at a time in synchronization with one clock signal and displayed on a display means (monitor camera). It goes without saying that this first clock signal has a period synchronized with the scanning of each line during photographing by the television camera. Therefore, doctors and others can observe the X-ray transmission image of the subject using a monitor camera under the same conditions as before, and during the observation, they may wish to record a still image in order to observe a particular part more closely. When this occurs, the transmission of pixel signals from the television camera is immediately stopped, and the pixel signals for one frame stored in the first memory are fixed. Naturally, the fixed one-frame pixel signal represents a still image of the specific portion. Next, this pixel signal of one frame is read out one line at a time in synchronization with a second clock signal and stored in a second memory, and based on the stored pixel signal, the pixels of the fixed one frame are A still image corresponding to the signal is stored on any recording medium. As described above, according to the present invention, the pixel signals of one frame of an X-ray transmission image obtained by scanning with a television camera (representing one still image) are once stored in memory, and then Since the data is read out at a much slower period than the reading period and stored in the recording medium based on the reading, a clear still image can be stored without increasing the X-ray dose.

(Example) Hereinafter, an apparatus for recording a still image of an X-ray transmission image according to the present invention will be described based on an example thereof with reference to the accompanying drawings.

As a configuration that forms an X-ray transmitted image of the subject using the irradiated X-rays from the X-ray irradiator, a television camera is provided to take this X-ray transmitted image, and the output of the television camera is converted into a digital signal by an AD converter. 1
A memory is provided for storing frames.

That is, place the subject 11 on the position setting table 12,
The position of the affected area to be photographed is fixed so that it falls within the irradiated X-ray Lx region from the X-ray irradiator 13. The position setting table 12 can be rotated three-dimensionally around the center, and this rotation changes the relative position between the subject and the X-ray irradiator 13. By rotating it, the irradiation angle of the X-rays irradiated from the X-ray irradiator 13 to the affected area is set to a desired angle. After setting the irradiation angle of X-rays to the affected area to a desired value, X-rays are irradiated from the X-ray irradiator 13 to form a transmitted X-ray image of the subject 11 on the image intensifier 14.

All electrical circuits are reset when the device is started. When the subject 11 is irradiated with X-rays by the X-ray irradiator 13,
The television camera 15 starts operating, and a transmitted X-ray image formed on the image intensifier 14 is photographed by the television camera 15. The output signal of the television camera 15 obtained corresponding to the transmitted X-ray image formed on the image intensifier 14 by this photographing is converted into a digital signal by the AD converter 16.

The digital signal obtained by the AD converter 16 is given as an input to the memory 17 via the switch 26, and the memory 17 contains an image signal for each frame corresponding to the transmitted X-ray image taken by the television camera 15. The pixel signals are divided and corresponding pixel signals are stored in association with respective addresses. For example, a 64K IC memory can be used as the memory 17.

Next, reading out one frame of pixel signals stored in the memory 17 will be described.

That is, the reference clock signal AC from the reference clock generator 10 is given to the pixel counter 18, and the pixel counter 18 gives the pixel clock signal Ap synchronized with the clock signal Ac to the memory 17, and also calculates the number of pixel signals for one line. A carry signal is generated every time a number of reference clock signals corresponding to
Au is generated and applied to the line clock signal generator 25. The line clock signal generator 25 generates a carry signal.
In synchronization _with Au _, line signals _{Al 1 , Al 2} , Al ₃ ,
...Al _o is generated, and at the same time, a line designation signal Al _c corresponding to the line signal is given to the memory 17. In addition,
The number of terminals tl ₁ , tl ₂ , tl ₃ , . . . _tlo is the same as the number of lines included in one frame.

As for the pixel signals stored in the memory 17, the pixel signals on the line designated by the line designation signal Al _c from the line clock signal generator 25 are sequentially read out in synchronization with the pixel clock signal Ap. A carry signal Au is generated at the timing when one line's worth of pixel signals are read out, the line designation signal designates the next line, and the pixel signals of the next line are sequentially read out in the same way. In this way, one frame of pixel signals is read out. The read pixel signal is converted into an analog signal by a D/A converter 27, and is provided to a monitor television 28 as a display signal. The above operations are repeated, and pixel signals representing the X-ray transmission image are continuously read out and provided to the monitor.

The reference clock signal Ac from the reference clock generator 10 is also supplied to the horizontal/vertical scanning circuit 29 of the monitor 28, so that the pixels stored in the memory 17 are synchronized with the reading of the pixel signals from the memory 17. Monitor 2 for the X-ray transmission image corresponding to the signal
Display on 8. It goes without saying that the timing of scanning and capturing the X-ray transmission image on the image intensifier by the television camera is also synchronized with the reference clock signal.

The above is a mechanism for displaying an X-ray transmitted image of a subject on a monitor, and is basically the same as the conventional technology. The features of the present invention will be explained below.

When the X-ray transmission image on the monitor 28 is monitored and the desired image is confirmed and the memory button is pressed, the switch 26 is turned OFF, the transmission of the image signal from the television camera is cut off, and the memory 17 contains the switch 26. The image signal indicating the X-ray transmission image immediately before the switch is turned off is fixed in a stored state. The image signal stored in the fixed memory 17 is read out in the manner described above and displayed on the monitor 29 as a still image.

A frame counter 9 shown in FIG. 1 is provided to record this still image. The frame counter 9 is started by the drive signal Ag given from the line clock signal generator 25, and becomes logic value "1" at the rising edge of the line signal Al ₁ for each frame, and the line signal Al _o of the same frame becomes logic value "1". Frame signals whose theoretical value becomes "0" at the falling edge are sequentially generated at terminals tf ₁ , tf ₂ , . . . tf _o . Therefore, the frame counter 9 receives the frame signals Af ₁ , Af ₂ , as shown in FIG. 3 5-7.
...Af _o is generated sequentially at its terminals tf ₁ , tf ₂ , ...tf _o .

The terminals tl ₁ , tl ₂ , tl ₃ , of the line clock signal generator 25
Line signals generated from ...tl _o Al ₁ , Al ₂ , Al ₃ , ... _Alo
The frame signals Af ₁ , Af ₂ , ... Af _o generated from the terminals tf ₁ , tf ₂ , ... _tfo are respectively connected to the AND circuit 21 -
1, 21-2, . . . 21-n, the line signals Al ₁ , Al 2 , Al ₂ ,
Outputs are generated sequentially at the timing of occurrence of Al ₃ ,... _Alo , and the outputs are given to the OR circuit 24 and OR
The circuit produces an output as shown in FIG. 3.11.
The output of the OR circuit is connected as a write signal to the write terminal tw of a register 30 having a capacity to store one line of image signals. The register 30 receives the image signal read from the memory 17, and outputs the OR circuit 24 to the write terminal tw.
In response to a write signal with a logical value of "1" given from , one line of the image signal input at that time is stored and held until the next write signal is input. In other words, the write signal that is the output of the OR circuit 24 is sequentially converted into a line signal for each frame.
It occurs in response to Al ₁ , Al ₂ , Al ₃ , ...Al _o , so
At the generation timing of each line signal, one line of the image signal input at that time is stored in the register 30. That is, first, during the period of the first frame, one line of image signals corresponding to the line signal Al ₁ is stored by a write signal responsive to the line signal Al ₁ , and is held until the next write signal is input. The next write signal is generated in response to the line signal Al ₂ delayed by one frame, and the image signal of the second line corresponding to the line signal Al ₂ is stored and held until the next write signal is input. Similarly below,
In the register 30, one frame of image signals is sequentially stored one line at a time from the memory 17, and is held for a period corresponding to at least one frame.

In this way, the 1 held in the register 30
The image signal for a line is recorded on an arbitrary recording medium using a period corresponding to at least one frame in which it is held. As a recording medium,
Any photosensitive paper, magnetic recording tape, magnetic disk, or the like used for developing ordinary photographs may be used, but in the following embodiments, a case where recording is performed on photosensitive paper will be explained.

The output terminal of the register 30 is connected to the input terminal of the DA converter 32, and the output terminal of the DA converter 32 has a 1
A line scanning type cathode ray tube 35 is connected. A clock signal Ac from the reference clock generator 10 is supplied to the horizontal scanning circuit 36 of the cathode ray tube 35.
The cathode ray tube 35 is repeatedly horizontally scanned by the clock signal Ac.

Therefore, the X-ray image signal for one line supplied from the DA converter 32 is converted into one scanning optical signal by the cathode ray tube 35, and this one scanning optical signal is sent to the cathode ray tube 35 via the optical fiber 8, for example. The X-ray image signal is supplied to a photosensitive paper 37 disposed in close opposition to each other, and the data corresponding to the X-ray image signal can be exposed to the photosensitive paper 37 and thermally developed for each scanning light signal.

In this case, one scanning light signal obtained by the cathode ray tube 35 can be supplied to the photosensitive paper 37 via a lens. If the number of scanning lines in one frame is N and P frames are transmitted every second, then
One scanning light signal is supplied to the photosensitive paper 37 for N×1/P seconds, and exposure and thermal development are performed.

A moving means is provided for moving the photosensitive paper onto which one line of data is irradiated in synchronization with the transfer by the transfer means.

That is, the photosensitive paper 37 is disposed so as to be movable in a direction perpendicular to the line direction data formed by the cathode ray tube 35 and supplied as one scanning optical signal.
One end of the photosensitive paper 37 is wound around a shaft 38, and this shaft 38 is configured to be rotatable in units of angle by a rotation motor 42. This rotation motor 42 is OR
It is configured to be rotated by a unit angle by the output signal of the circuit 24.

Therefore, in response to the transfer of the first line of data of the X-ray image signal stored in the memory 17 to the register 30, the rotation motor 42 rotates by a unit angle, and the photosensitive paper 37 is rotated at that rotation position. On the other hand, data for the first line is repeatedly transferred as one scanning optical signal via the cathode ray tube 35 during one frame. In this way, one scanning light signal from the cathode ray tube 35 is used to
The data for each line is exposed to light on the photosensitive paper 37 and thermally developed to be completely copied.

Next, the data for the second line is stored in the register 30.
, the photosensitive paper 37 rotates by a unit angle, and at that position, the data for the second line is repeatedly transferred to the photosensitive paper 37 for one frame by the cathode ray tube 35 as one scanning light signal.

Thereafter, data up to the n-th line is transferred onto the photosensitive paper 37 in the same manner, and the X-ray image signal stored in the memory 17 is completely copied onto the photosensitive paper 37. Exposure and thermal development during copying are performed automatically, and the transfer of one frame is completed in about 14 seconds, for example.

Although not shown, the structure is such that thermal development is performed continuously following exposure, and if necessary, the photosensitive paper on which the X-ray image signal has been copied is automatically cut with a cutter and taken out. There is.

The outline emphasizing circuit CE is shown in Fig. 2 along with its peripheral connection parts.
A second embodiment of the present invention is constructed by connecting, for example, between the DA converter 32 and the cathode ray tube 35.

In this second embodiment, the analog signal obtained by the second DA converter 32 is given as an input signal to a delay circuit 43 and a processing circuit 44. In the processing circuit 44, for example, by differentiating the input signal under predetermined conditions, a signal emphasis addition part is formed at the necessary edge, and this is combined with the original signal passed through the delay circuit 43. A circuit 45 synthesizes the signals. Therefore, the analog signal obtained at the output terminal of the synthesis circuit 45 becomes a signal whose outline in the horizontal direction is emphasized under predetermined conditions.

Alternatively, the contour emphasizing circuit CE may be operated digitally, and the contour may be digitally emphasized under predetermined conditions. In this case, the contour emphasizing circuit CE is inserted before the second DA converter. Note that this is not limited to contour enhancement by the contour enhancement circuit CE.
The configuration can be such that various image processing such as coloring a predetermined region of an X-ray transmission image can be performed.

In this way, in the present invention, the transmitted X-ray image of the subject 11 can be monitored on the monitor 28, and the necessary images can be confirmed through this monitoring and the switch 2
When 6 is turned OFF, the image is stored in memory 17.
can be memorized. In this case, monitor 2
In order to accurately confirm the image on the monitor 8, for example, the memory 17 may be read multiple times and the same image may be displayed on the monitor 28 during this period. In this way, it is possible to select only the necessary transmission X-ray images, and the selected X-ray image signals are transferred line by line to the register 30, held for a period equivalent to at least one frame, and then retrieved. As one scanning light signal, the photosensitive paper 37 is sequentially exposed for one line at a time for sufficient time and thermally developed. Since the photosensitive paper 37 is moved for each line, the transmitted X-ray images for all lines can be copied onto the photosensitive paper 37 as clear images.

With the present invention, the X-ray image on the monitor 16 can be formed with a small amount of X-rays, so there is no need to irradiate the subject with strong X-rays, and the amount of exposure to the examiner who operates the device can be reduced to, for example, 1/10 of that of conventional methods. This makes it possible to significantly reduce the amount. Also, the X-ray image signals stored in memory 17 can be read out at low speed and transmitted via an acoustic coupler over a low speed transmission line, such as a local telephone line. Therefore memory 1
In this way, the X-ray image signal stored in 7 can be transmitted to a hospital with a specialist using a telephone line for detailed diagnosis, or it can be used for emergency diagnosis in the absence of a doctor. It is.

Data related to the X-ray image signals obtained in the memory 17 can be connected to a host computer through a minicomputer and filed, and various data processing can be performed using various computer peripheral devices.

Alternatively, by connecting a cassette magnetic tape device to the device of this invention via a magnetic tape control module, recording the obtained X-ray image signals on the magnetic tape, and directly taking out and copying from the magnetic tape in a batch method, It is also possible to efficiently process and utilize various types of X-ray images.

In the embodiment described above, since a still image was recorded on photosensitive paper, the image signal for one line stored in the register 30 was repeatedly read out during its retention period and converted into an optical signal. However, when recording on a magnetic tape or the like, During the retention period, it is possible to read out one line of image signals at low speed and record them while driving the magnetic tape at low speed, thereby making it possible to record still images on magnetic tape with high frequency characteristics. Therefore, it can be used to reproduce still images with high clarity.

(Effects) Since the present invention is configured as described above, by using an X-ray transmission image that is normally displayed on a monitor television for observation, one image corresponding to a desired still image in the X-ray transmission image is displayed. Fix the image signal for a frame, read out the fixed image signal line by line, hold it for a period corresponding to at least one frame cycle, and arbitrarily read out the image signal for the stored line during the holding period. Since the image is recorded on the recording medium, a clear still image can be recorded on the recording medium in a reproducible manner without increasing the amount of irradiated X-rays.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of an apparatus for recording a still image of an X-ray transmission image according to the present invention, and FIG. 2 is a diagram showing the configuration of a contour enhancement circuit used in another embodiment of the present invention. , FIG. 3 is an operation waveform diagram of each part of the embodiment of FIG. 1. 37: Photosensitive paper.

Claims (1)

[Claims for Utility Model Registration] A television camera that continuously takes X-ray transmission images of a non-stationary subject and sends out pixel signals representing the X-ray transmission images; and a first memory for sequentially receiving and storing one frame of the latest pixel signal; and synchronizing the one frame of the pixel signal stored in the first memory with a predetermined first clock signal; pixel signal reading means for sequentially reading out one line at a time; and receiving the pixel signal read out by the pixel signal reading means, and
means for visually displaying a line transmission image; means for stopping transmission of the pixel signal from the television camera and fixing the pixel signal stored in the first memory; and the first a second memory for sequentially reading and storing the fixed pixel signals stored in the memory one line at a time in synchronization with a second clock signal having a period corresponding to at least one frame of the pixel signals; and means for storing a still image corresponding to the fixed pixel signal in a predetermined recording medium based on the pixel signal stored in the second memory, A recording device.