JP3230843B2 - X-ray diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diagnostic apparatus.

[0002]

2. Description of the Related Art Conventionally, in an X-ray diagnostic apparatus, a transmitted X-ray from a subject is converted into an optical image by an image intensifier (II) or the like, and the optical image is converted by an imaging tube or the like. An image is taken and displayed on a display means such as a monitor (such a method is generally called X-ray fluoroscopy). However, with the stop or end of the X-ray irradiation, the image display on the monitor also ends.
Therefore, an image at the end of X-ray exposure is stored in a memory so that the image display can be continued even after the X-ray exposure is stopped or terminated, and the stored image is repeatedly supplied to a monitor. To continue the image display. Such a method is generally called LIH (Last Image Hold).

However, since the X-ray irradiation for X-ray fluoroscopy and the operation of the image pickup tube are not necessarily synchronized, for example, as shown in FIG. It may be stored in the memory. That is, this is because the X-rays are turned off during the scanning period of the image pickup tube, and the brightness of the image is locally reduced. Therefore, as a method of obtaining a stable image without flicker,
(1) A method of applying a delay from the operation of turning off the fluoroscopy to actually stopping the X-ray, stopping the X-ray after storing the image (see FIG. 3B), and (2) a backup memory There is a method (see (C) in FIG. 3) in which (at least one field's worth of memory) is secured and the two previous fields when fluoroscopy is turned off are displayed as stored images.
Alternatively, the image obtained by the method (2) is hereinafter referred to as LIH (Last I
mage Hold)).

[0004]

However, the above a
According to the method of (1), it is necessary to control the stop of the X-rays on the memory side, and the fluoroscopy
Even when the FF operation is performed, there is a problem that the X-ray may not stop immediately or the memory may fail to stop the X-ray. In addition, according to the above method b, there is a problem that the cost is increased by the amount of the backup memory, and that the circuit is complicated by securing the backup memory.

According to the present invention, in order to solve the above-mentioned problem, when an image at the time of stopping X-ray fluoroscopy is stored in a memory, an X-ray on the memory side is obtained in order to obtain an image having a stable level without flicker (brightness fluctuation). It is an object of the present invention to provide an X-ray diagnostic apparatus that does not need to control fluoroscopy and does not require a backup memory.

[0006]

According to the first aspect of the present invention, there is provided an image pickup apparatus for outputting input image pickup light as image data, and a memory for storing the image data. An X-ray diagnostic apparatus comprising: a control unit configured to control X-ray irradiation and writing of the image data into the memory; and an image display device that displays the image data as an image. The apparatus includes a charge transfer device that converts the imaging light into a charge signal through the steps of accumulating charges and transferring the charges and transferring the imaging light to the memory in synchronization with a field shift pulse that controls transfer timing. In the charge transfer device, if X-ray irradiation is being performed at the time of outputting a field shift pulse, image data is written to the memory. Control means for controlling the writing of image data to the memory to be stopped if there is no projection, and a monitor for repeatedly supplying and displaying the final image data stored in the memory by the control means. The characteristic X-ray diagnostic apparatus is a solution.

[0007]

[0008]

According to the present invention, when X-ray fluoroscopy is stopped, the memory writes data (charge) for one field or one frame transferred by the charge transfer device immediately before X-ray fluoroscopy is stopped. Data after the X-ray fluoroscopy is stopped is not written, so that flicker does not occur.

[0009]

FIG. 1 is a block diagram showing an embodiment of an X-ray diagnostic apparatus according to the present invention.

In FIG. 1, an X-ray high-voltage generator 2, whose output is controlled by a control unit 1, an X-ray tube 3, a subject 4, and an X-ray beam that has passed through the subject 4, are converted into optical images and amplified. An X-ray including an image intensifier tube 5, an imaging device 7 for inputting an output optical image of the image intensifier tube 5 through an optical system 6 and outputting the image signal as a video signal, and a TV monitor 10 for receiving the video signal and displaying an image. A diagnostic device is shown. The imaging device 7 has a CCD 8 and a memory 9 as a charge transfer device that converts input light into a charge signal, and stores and transfers the charge signal. The memory 9 determines under the timing control from the control unit 1 to start or stop writing of the input from the CCD 8 as image data. The imaging device 7 has a solid-state imaging device (CCD in this embodiment) 8 for converting an optical image from the image intensifier into a video signal, and a memory 9. The memory 9 stores the CCD 8 under the timing control of the control unit 1.
The writing of the video signal from is executed.

In general, the CCD 8 includes a storage unit that receives input light and stores the corresponding electric charge, and a transfer unit that sequentially outputs the electric charge stored in the storage unit to the outside. The electric charge stored in the storage unit is It is instantaneously transferred to the transfer unit by a charge transfer signal called a field shift pulse. Thereafter, the charges in the transfer unit are sequentially output to the outside as video signals by charge transfer signals called vertical transfer pulses and horizontal transfer pulses.

Next, the operation of the X-ray diagnostic apparatus according to the present embodiment configured as described above will be described with reference to FIGS. 2A and 2B.
This will be described in detail with reference to FIG.

FIG. 2A is a timing chart showing one example of one X-ray fluoroscopic diagnosis, and FIG.
It is a figure which shows the operation | movement timing before and behind fluoroscopic X-ray OFF in (A) in detail. In FIG. 2A, Pa, P
b, Pc, Pd, Pe are CC in periods A, B, C, D, E
D8 is a field shift pulse for transferring the charges respectively stored in the storage unit to the transfer unit. For example, the charges stored in the period A are transferred to the transfer unit by the field shift pulse Pa, and the video signal is sequentially transferred during the period B. Output to the memory 9 as a. In the memory 9, writing is performed based on the timing of the field shift pulse Pa from the control unit 1 and the timing of the X-ray ON / OFF signal. Next, the video signal a written in the memory 9 is read out during the period C, supplied to the TV monitor 10, and displayed as a fluoroscopic image. Hereinafter, the electric charges accumulated in the CCD 8 during the periods B, C, and D are also displayed on the TV monitor 10, but the electric charge accumulated during the period E depends on the timing of the field shift pulse Pe from the control unit 1 and the X-ray ON / OFF. Writing is prohibited (stopped) based on the timing of the OFF signal. in this case,
The video signals c and d are repeatedly supplied from the memory 9 to the TV monitor 10, and a period E and T
The display image on the V monitor is a display image corresponding to the video signals c and d.

Next, the operation timing before and after the X-ray is turned off will be described in detail with reference to FIG.

Generally, the operation of the memory is suspended until the memory finishes writing the video signal of one field from the CCD and starts writing the next field.
In this embodiment, this period is called a blanking period.

In FIG. 2A, a CCD output d is a charge signal read by a field shift pulse Pd, and this signal is a signal accumulated in a previous field or frame. In other words, even if the X-ray fluoroscopy is stopped, the memory 9 writes the data (charge) for one field or one frame transferred by the CCD 8 immediately before the X-ray fluoroscopy is stopped. Since the data after X-ray fluoroscopy is stopped is not written, the signal is stable as a level.

The memory 9 performs data writing or writing stop by a timing signal for stopping X-ray fluoroscopic transmission from the control unit 1 and a field shift pulse, and when the field shift pulse falls, X-ray fluoroscopic observation is performed. If the stop timing signal is ON, the writing is continued, and if it is OFF, the writing is stopped. This determination is made at a point during the blanking end period from the fall of the field shift. Note that the field shift pulse may be directly input to the memory 9 or the field shift pulse is normally output at a predetermined time from the start of blanking. The stop timing may be determined.

The embodiments of the present invention have been described above.
The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made.

[0019]

As described above, according to the X-ray diagnostic apparatus of the present invention, it is not necessary to send a timing signal for stopping X-ray fluoroscopy by stopping writing to the memory from the memory to the control unit. Without having to provide a flicker-free LIH image with a stable level. In addition, X-ray irradiation stop
The radiation dose is reduced. Further, since the circuit scale can be reduced, the configuration of the device is simplified and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an X-ray diagnostic apparatus according to the present invention.

FIG. 2 is a timing chart of the embodiment of FIG. 1, and FIG. 2B is a detailed timing chart of FIG.

FIG. 3 shows a timing chart according to the prior art, wherein FIG. 3 (A) shows a case without flicker prevention, FIG. 3 (B) shows a case with the conventional method (1), and FIG. The case according to the method (2) of the prior art is shown.

[Explanation of symbols]

Reference Signs List 1 control unit 2 X-ray high-voltage generator 3 X-ray tube 4 subject 5 image intensifier tube 6 optical system 7 imaging device 8 CCD (charge transfer device) 9 memory 10 TV monitor (image display device) Pa, Pb, Pc, Pd field shift pulse (timing pulse)

Claims (1)

(57) [Claims] An imaging device that outputs input imaging light as image data; a memory that stores the image data; and a control unit that controls X-ray emission and writing of the image data into the memory. And an image display device that displays the image data as an image, wherein the imaging device converts the imaging light into a charge signal through a step of accumulating charges and transferring the charges. And a charge transfer device for transferring to the memory in synchronization with a field shift pulse for controlling transfer timing. In the charge transfer device, if X-ray irradiation is being performed at the time of output of the field shift pulse, the charge transfer device A control means for performing writing of image data, and controlling to stop writing of image data to the memory if there is no X-ray exposure at the time of outputting the field shift pulse; When, X-rays diagnostic apparatus characterized by comprising: a monitor that performs the final image data stored in memory is repeatedly supplied displayed by the control means.