JP4006255B2 - Radiation imaging equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radiographic imaging apparatus using a portable radiographic imaging cassette.
[0002]
[Prior art]
With recent advances in semiconductor process technology, apparatuses for taking radiographic images using semiconductor sensors have been developed. These systems have a very wide dynamic range as compared with a radiographic system using a conventional photosensitive film, and can obtain a radiographic image that is hardly affected by fluctuations in the exposure dose of radiation. Further, unlike the photosensitive film system, no chemical treatment is required, and an output image can be obtained immediately.
[0003]
In general, a phototimer (AEC: Auto Exposure Control) is used in order to set an imaging dose to an appropriate amount during X-ray imaging. Also, in a general X-ray room, a standing frame is used for standing position imaging, and a standing table frame is used for standing position imaging, and each of the standing position table and the standing table frame is used. A phototimer is installed, connected to an X-ray device, and used to block exposure.
[0004]
An electronic portable cassette having an X-ray monitor is also known, but this X-ray monitor is used only for driving a sensor such as integrating charges inputted to the sensor.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional example, the phototimer incorporated in the gantry occupies a large volume capacity when including the attached parts, so a highly reliable phototimer cannot be incorporated in the cassette, and the electronic cassette The phototimer is not used at the time of shooting, or even if it is used, a phototimer is installed on each frame. Since this phototimer is expensive, installing a phototimer for each of a plurality of mounts is an obstacle to cost reduction of the entire system. Further, since maintenance and management of the phototimer takes time, it is desired to reduce the number of phototimers.
[0006]
An object of the present invention is to solve the above-mentioned problems, and by using a technique such as disclosed in Japanese Patent Laid-Open No. 9-73144, a small phototimer is provided inside the electronic cassette, so that one photo can be obtained. It is an object of the present invention to provide a radiographic imaging apparatus in which a timer can be easily used on any standing stand or stand-up table stand.
[0007]
[Means for Solving the Problems]
The radiographic imaging apparatus according to the present invention for achieving the above object, converting the X-ray generating means for generating X-rays, and X-ray generator which controls the X-ray generating means, the X-ray data sensor And an electronic cassette having a cutoff signal output terminal for outputting an X-ray cutoff signal from the phototimer.
A plurality of mounts each having a cut-off signal input terminal for mounting the electronic cassette and electrically connecting to the cut-off signal output terminal, and each of the cut-off signal input terminals of the plurality of mounts is The X-ray generator is connected to an X-ray generator, and when the X-ray generator receives an X-ray cutoff signal from the electronic cassette, the X-ray generator generates X-rays from the X-ray generator. It is characterized by controlling .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the illustrated embodiment.
FIG. 1 is a configuration diagram of a radiographic image capturing apparatus according to the present embodiment, FIG. 2 is a flowchart diagram of X-ray blocking judgment, and an electronic cassette 1 is composed of an amorphous semiconductor or the like and includes a two-dimensional detection unit. Sensor unit, a reading unit that AD converts the charge of the sensor unit, a data transfer unit that transfers the read data wirelessly or by wire, a photo timer 2, and a cutoff signal output terminal 3 that outputs a signal from the photo timer 2 Has been. The phototimer 2 is preferably configured by a semiconductor sensor, so that a thin one can be realized. However, the phototimer 2 is not limited to this and may be based on an ionization chamber.
[0010]
Furthermore, the phototimer 2 may be formed in the same plane as the above-described sensor unit in the process of forming a semiconductor. When formed in the same plane, the phototimer 2 is formed in a stripe shape so as to be embedded between pixels of the sensor unit, and the phototimer 2 is formed by several stripe-shaped sensors.
[0011]
The radiographic imaging apparatus can be equipped with such an electronic cassette 1 and has an upright stand 5 and an upright table base 6 each having a cut-off signal input terminal 4, and further upright stand 5 and an upright side table base. 6 is connected to an X-ray generator 8 provided with an X-ray tube 7 for irradiating X-rays.
[0012]
In the electronic cassette 1, the standing base 5 or the standing table base 6 to be mounted is selected depending on the portion of the subject to be photographed. For example, when photographing the chest and cervical vertebrae, the standing frame 5 is used, and when photographing the abdomen and lumbar vertebrae, the standing table frame 6 is used for imaging. When photographing, the electronic cassette 1 is mounted on the standing base 5 or the standing table base 6, and the cutoff signal output terminal 3 of the electronic cassette 1 is connected to the cutoff signal input terminal 4 of the standing base 5 or the standing table base 6. To do.
[0013]
In some cases, the patient may take an image while holding the electronic cassette 1, or the electronic cassette 1 may be taken by placing the electronic cassette 1 on the prone table base 6. In that case, the interruption signal input terminal provided in the cable extended from the interruption signal input terminal 4 of the standing base 5 or the standing table base 6 is connected to the interruption signal output terminal 3 of the electronic cassette 1.
[0014]
The output signal from the phototimer 2 may be an analog signal or may be in the form of a digitized cut-off signal. However, when output as an analog signal, the signal is amplified by an amplifier (not shown). It is transmitted and integrated on the receiving side, and the X-ray is cut off when a predetermined threshold value is reached. When output as a digital signal, when the charge from the sensor unit is integrated inside the electronic cassette 1 via an amplifier or the like and compared with a predetermined threshold stored inside, the point when the threshold is exceeded To output an X-ray cutoff signal (ON / OFF). When there are a plurality of X-ray tubes 7, the preset threshold value may be set by tube information for each tube.
[0015]
Further, the X-ray tubes 7 used for the standing platform 5 and the standing table platform 6 may be different, and the radiation quality adjustment filters (not shown) arranged on the front surfaces of the X-ray tubes 7 are different. May be set to radiation quality. In this case, it is desirable to adjust the threshold value depending on the X-ray tube 7 used for imaging. Further, even if the same X-ray tube 7 is used, the tube quality is changed when the tube voltage is changed. Therefore, the threshold value can be made to depend on the tube voltage information.
[0016]
Furthermore, in a system in which the imaging tube voltage is determined in advance depending on imaging regions such as the chest and abdomen, the X-ray blocking threshold value may be controlled depending on the imaging region information.
[0017]
As shown in FIG. 1, signal lines from a plurality of cutoff signal input terminals 4 are connected to an X-ray generator 8, and even if there are a plurality of input lines, only one signal is temporarily activated. Therefore, the X-ray generator 8 may block X-rays from the X-ray tube when an X-ray blocking signal is input from at least one line.
[0018]
In addition, when the cutoff signal is an analog signal, it is conceivable that the respective lines are separately integrated in parallel and the X-rays are cut off when the output of any one of the integration circuits exceeds a threshold value. If there is a detection means for detecting which cutoff signal input terminal 4 is connected to the electronic cassette 1, a line to be integrated may be selected using the detection signal. In this case, it is not necessary to provide a plurality of integrating circuits, and the apparatus becomes inexpensive.
[0019]
【The invention's effect】
As described above, the radiographic image capturing apparatus according to the present invention conventionally needs to provide a phototimer for each gantry. However, only the phototimer mounted on the electronic cassette is used to capture images corresponding to a plurality of gantry. can do.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a radiation imaging apparatus.
FIG. 2 is a flowchart of X-ray cutoff determination.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electronic cassette 2 Phototimer 3 Cutoff signal output terminal 4 Cutoff signal input terminal 5 Standing stand 6 Standing table stand 7 X-ray tube 8 X-ray generator

Claims (6)

X-ray generation means for generating X-rays;
An X-ray generator for controlling the X-ray generator;
An electronic cassette including a sensor unit for converting X-rays into data and a phototimer for blocking X-rays, and having a cutoff signal output terminal for outputting an X-ray cutoff signal from the phototimer;
A plurality of mounts each having a cutoff signal input terminal for mounting the electronic cassette and electrically connecting with the cutoff signal output terminal;
The cutoff signal input terminals of the plurality of mounts are connected to the X-ray generator, and the X-ray generator receives the X-ray cutoff signal from the electronic cassette when the X-ray generator receives an X-ray cutoff signal from the electronic cassette. A radiographic imaging apparatus, wherein the generator controls generation of X-rays from the X-ray generator . The radiographic image capturing apparatus according to claim 1, wherein the X-ray generation unit includes a plurality of X-ray tubes . Radiographic imaging apparatus according to claim 2 wherein the X-ray generating apparatus, characterized by controlling the condition for blocking X-rays in dependence on the tube voltage of the X-ray generating means. The radiographic image capturing apparatus according to claim 1 , wherein the X-ray generation apparatus controls a condition for blocking X-rays for each of the plurality of mounts . The radiographic image capturing apparatus according to claim 1 , wherein the phototimer is formed between pixels of the sensor unit . The radiographic imaging apparatus according to claim 1, wherein the X-ray generation device stops generating X-rays from the X-ray generation unit when an X-ray cutoff signal is input.

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