JPH07148163A - X-ray imaging device - Google Patents

Abstract

PURPOSE:To provide X-ray images of high quality without any exposure to radiation more than necessary, by adding a means for increasing the acceptance for operation of an X-ray imaging device, which determines the radiation time of an X-ray generator based on the inputted data on the patient's physique, the region to be imaged, and the gain. CONSTITUTION:An operator presses the corresponding one of physique select switches 22 after judging the patient's physique and presses the corresponding one of region select switches 23 according to the region to be imaged. Then, the operator presses the corresponding one of gain select switches 6 based on the symptom to be examined. For example, when treating carious teeth, root canals, or the like, the operator selects a high gain switch to get a small quantity of irradiation dose and an image of low quality, and when treating periodontitis, cancer, or the like, the operator selects a low gain switch from the gain select switches 6 and press said witch to get a large quantity of irradiation dose and an image of high quality. Consequently, a predetermined irradiation time is determined based on the combinations previously stored in a table 21 and indicated to an X-ray controller 20. After that, when an irradiation switch 15 is pressed, the X-ray controller 20 sends an irradiation signal corresponding to the X ray generating period to an X-ray generator 10 based on the determined irradiation time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus for detecting an X-ray image of a subject such as an intraoral region as an electric signal and displaying the image on a CRT (cathode ray tube) or the like.

[0002]

2. Description of the Related Art Conventionally, in order to obtain an X-ray image of an intraoral region, a film system has been widely used in which a photosensitive recording material such as a silver salt film is used for X-ray photography and then development and fixing processes are carried out. Has been done.

However, this film system requires 1) about 2 minutes or more from the time of X-ray photography to the observation.
2) A developing device and a processing solution for developing and fixing are indispensable. 3) The X-ray sensitivity of silver salts is limited, and a constant X-ray dose is required to obtain a desired image density.
4) The image once fixed cannot be corrected. There are problems such as.

In order to solve such a problem, CCD
There has been proposed an X-ray image capturing apparatus which displays an image on a CRT (cathode ray tube) or the like after converting the X-ray image into an electric signal by using an image sensor such as (charge-coupled device). This X-ray image capturing apparatus is a so-called filmless system that does not use a photosensitive recording material such as a silver salt film, and can be observed in real time from 1) X-ray capturing. 2) No developing device or processing liquid is required. 3) Since the X-ray sensitivity characteristic of the image sensor is linear, the X-ray irradiation amount can be reduced. 4) It becomes easy to perform various kinds of image processing on the detected X-ray image and to copy and store the image. It has features such as.

[0005]

In the conventional X-ray photography system using a silver salt film, the sensitivity of the film is constant, but in the X-ray image photography apparatus using the image pickup device, it depends on the gain of the signal processing circuit. The sensitivity changes. That is, if the X-ray irradiation amount (= X-ray intensity × irradiation time) is increased, X
The quantum effect of the line is reduced, and a higher definition image is obtained,
On the other hand, if the X-ray irradiation amount is reduced, the image quality deteriorates,
The dose to the patient can be reduced. As described above, the X-ray irradiation dose can be arbitrarily selected depending on the combination of the image quality and the exposure dose. In order to obtain an appropriate image regardless of the X-ray irradiation dose, the X-ray irradiation dose and the signal processing are performed. It is necessary to link with the gain of the circuit.

However, in the conventional X-ray image capturing apparatus, the X-ray generating apparatus side and the X-ray image capturing apparatus side are installed independently of each other, so that the X-ray generation conditions such as the X-ray irradiation amount are adjusted. If you do, operate the X-ray generator side, while
When adjusting the image processing conditions such as the gain of the signal processing circuit, it is necessary to operate the X-ray image capturing apparatus side, which complicates the adjustment work.

Further, the relationship between the X-ray irradiation dose and the gain is
It is not easy for the surgeon to operate the two devices while keeping this relationship in mind, because if one value is increased and the other value is decreased, an appropriate image cannot be obtained. Requires.

In order to solve the above-mentioned problems, an object of the present invention is to improve the operability of X-ray photography by making it possible to adjust the X-ray generation condition and the image processing condition in conjunction with each other.
Moreover, it is an object of the present invention to provide an X-ray image apparatus capable of obtaining an X-ray image with good image quality while preventing unnecessary exposure.

[0009]

According to the present invention, there is provided an X-ray generation means for irradiating an object with X-rays, and an X-ray control means for controlling an X-ray irradiation time of the X-ray generation means, Image pickup means for picking up an X-ray image that has passed through the subject, amplification means for amplifying the signal from the image pickup means with a predetermined gain, and the X-ray image by processing the signal from the amplification means. In an X-ray imaging apparatus including image processing means for displaying, a physique information selecting means for inputting physique information of the subject, an imaging part information input means for inputting imaging part information of the subject, Gain setting means for setting the gain of the amplifying means, physique information input by the physique information input means, imaging part information input by the imaging part information input means, and setting by the gain setting part Based on gain information There are an X-ray imaging apparatus characterized by comprising an irradiation time determining means for determining the X-ray irradiation time of the X-ray generating means.

Further, according to the present invention, X-ray generating means for irradiating the subject with X-rays, X-ray controlling means for controlling the X-ray irradiation time of the X-ray generating means, and the subject are passed. X
Image pickup means for picking up a line image, amplifying means for amplifying the signal from the image pickup means with a predetermined gain, and image for processing the signal from the amplifying means to display the X-ray image In an X-ray imaging apparatus including a processing unit, a physique information input unit for inputting physique information of a subject, an imaging region information input unit for inputting imaging region information of the subject, and the X-ray image Based on image quality selection means for selecting image quality, physique information input by the physique information input means, imaging region information input by the imaging region information input device, and image quality information selected by the image quality selection device hand,
An X-ray imaging apparatus comprising: an X-ray irradiation time of the X-ray generation means and an irradiation time gain determination means for determining a gain of the amplification means.

[0011]

According to the present invention, since the X-ray transmission intensity changes depending on the physique of the subject, the imaged region, etc., the physique information and the imaged region of the subject are detected by the physique information selecting means such as a panel switch and the photographic region information inputting means. Since the signal intensity, the image quality, and the like of the X image are changed by inputting information and the gain of the amplifying means, the gain is set by the gain setting means such as a panel switch. Then, based on these physique information, imaging region information and gain information,
An irradiation time determining means such as a numerical operation circuit or a numerical table determines the X-ray irradiation time. Therefore, the operator only needs to instruct the physique information, the imaging part information, and the gain information,
Appropriate X-ray generation conditions and image processing conditions can be set easily and reliably.

Further, according to the present invention, the physique information and the photographic part information of the subject are input by the physique information selecting means such as a panel switch and the photographic part information inputting means, and the image quality of the X-ray image, for example, by the high X-ray dose. Select a high-resolution image or an image with a feeling of roughness due to a low X-ray dose. Then, the irradiation time gain determining means such as a numerical calculation circuit and a numerical table determines the X-ray irradiation time and the gain based on the physique information, the imaging region information, and the image quality information. Therefore, the operator can easily and surely set the appropriate X-ray generation condition and image processing condition only by instructing the physique information, the imaging part information, and the image quality information.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the state of use of the X-ray imaging apparatus according to the present invention, showing an example in which the subject is an intraoral site. The X-ray generator 10 is attached to the swivel arm 12 so as to be vertically swingable and horizontally rotatable, and the X-ray irradiation tube 11 is oriented so that X-rays are irradiated toward the intraoral site of the patient 1. Adjusted.

On the other hand, the X-ray irradiation cylinder 11 with the intraoral region sandwiched therebetween.
The image pickup device 2 for detecting the X-ray intensity distribution that has passed through the intraoral site, that is, the X-ray image, is positioned at a position opposed to. In FIG. 1, the patient himself holds the positioning member 2a fixed to the image sensor 2 with his / her finger so that the image plane of the image sensor 2 faces the X-ray irradiation direction.

The image pickup device 2 includes a scintillator plate made of a rare earth element compound for converting X-ray photons into visible light, and visible light emitted from the scintillator plate.
An optical fiber array that transmits the dimensional distribution as it is, a CCD array sensor that receives the visible light distribution transmitted by the optical fiber array, accumulates the charges generated, and sequentially reads the charges accumulated for a predetermined time and converts them into electrical signals. A lead plate for preventing the incidence of scattered X-rays is provided on the back surface of the CCD array sensor, and these are housed in a housing made of synthetic resin or the like. The X-ray image detected by the image sensor 2 is converted into an electric signal by the CCD array sensor, passed through the signal cable, amplified by the variable gain amplifier 2 (see FIG. 2) with a predetermined gain, and input to the image processing device 4. To be done.

The image processing device 4 digitizes the image signal detected by the image pickup device 2 and stores it in a memory, and then performs a predetermined image processing to display it on a monitor device 5 such as a CRT (cathode ray tube). , Print on recording paper to get a hard copy.

FIG. 2 is a block diagram showing the electrical construction of an X-ray imaging apparatus which is an embodiment of the present invention. The X-ray imaging apparatus includes an X-ray generator 10 for irradiating an object 1a such as a tooth with X-rays, and an X-ray controller 20 for controlling the X-ray irradiation time of the X-ray generator 10. , An exposure switch 15 for activating the X-ray control device 20 to perform X-ray exposure, an image sensor 2 for capturing an X-ray image that has passed through the subject 1a, and an image converted by the image sensor 2. A variable gain amplifier 3 for amplifying a signal with a predetermined gain; an image processing device 4 for taking in an image signal output from the variable gain amplifier 3 and performing a predetermined image processing;
A gain controller 7 for controlling the gain of the variable gain amplifier 3 is provided with a monitor device 5 for displaying and recording the image data processed by the image processing device 4 and a video printer (not shown). And a gain selection switch 6 for instructing the gain controller 7 of the gain to be set.
And a physique selection switch 22 for inputting the physique information of the patient 1, a photographic part selection switch 23 for inputting photographic part information of the patient 1, and the physique information and imaging part selection input by the physique selection switch 22 A table 21 for determining the X-ray irradiation time of the X-ray generator 10 is provided based on the imaged region information input by the switch 23 and the gain information selected by the gain selection switch 6.

The X-ray generator 10 generates X-rays by applying a high voltage to the X-ray tube based on an irradiation signal output from the X-ray controller 20 with a predetermined tube voltage and a predetermined tube current. To do. Note that the X-ray irradiation amount is adjusted depending on the size of the irradiation time, and the tube voltage and the tube current are often not changed once set.

When the exposure switch 15 is pressed, the X-ray control device 20 outputs an irradiation signal corresponding to the X-ray generation period based on the irradiation time indicated by the table 21.
Output to 0.

In the image pickup device 2, charges accumulated for a predetermined time are periodically read out as a dark current based on a constant clock signal so that excess charges caused by thermal excitation or scattered X-rays do not remain. The reading operation is stopped during X-ray imaging to accumulate electric charges, and the reading operation is restarted after the X-ray imaging.

The variable gain amplifier 3 changes its amplification factor based on the gain signal output from the gain control section 7. For example, the ratio of the feedback resistance of the operational amplifier is switched step by step by a relay or by a voltage signal. A VCA (voltage control amplifier) or the like that can continuously adjust the gain is used.

The gain selection switch 6 is, for example, as shown in FIG.
As shown in (b), a high gain H that suppresses the X-ray dose and amplifies the signal of the image sensor 2 with high sensitivity, a middle gain M that amplifies with medium sensitivity, and a low gain L that increases the X-ray dose with low sensitivity.
Panel switch 6a, 6b, 6c that can select three stages
The desired gain is selected by pressing one of the panel switches, and the lamp P above it is turned on. Note that the selectable gain is not limited to three levels, and may be a continuously variable one such as a variable volume.

The gain controller 7 is composed of a CPU (central processing unit) or the like, and outputs a gain signal to the variable gain amplifier 3 based on the gain selected by the gain selection switch 6 and also to the table 21. Output information.

The physique selection switch 22 is, for example, as shown in FIG.
As shown in (a), panel switches 22a, 22b, 22c, which can select four stages of child, female, standard, and obesity,
22d, the physique information of the patient 1 is input by pressing one of the panel switches, and the lamp P above it is turned on. The physique information that can be selected is not limited to four levels, and may be continuously adjustable such as a variable volume.

As shown in FIG. 3 (a), for example, the radiographic region selection switch 23 has upper jaws 1 to 3, lower jaws 1 to 3, upper jaws 4 and 5, and lower jaws 4 and 5. It consists of panel switches 23a to 23g that can select 5th, 6th to 8th upper jaw, 6th to 8th lower jaw, and 7 stages of occlusion, and the imaged part of the patient 1 is pressed by pressing any panel switch. Information is input, and the lamp P above or below the information is turned on. It should be noted that the imaged part information that can be selected is 7
It is not limited to stages.

As described above, the table 21 is irradiated with X-rays corresponding to a combination of, for example, four stages of physique information, seven stages of imaging region information, and three stages of gain information, for a total of 84 (= 4 × 7 × 3). The time is stored in advance in a storage element such as a memory, and the X-ray irradiation time determined by input of each information is instructed to the X-ray controller 20. The irradiation time thus determined is displayed on the number display panel 24 shown in FIG. Instead of the table 21, a numerical operation circuit that digitizes each information and performs a predetermined calculation may be used.

Next, the operation will be described. First, the surgeon looks at the physique of the patient 1 and presses the corresponding physique selection switch 22 and then the imaging site selection switch 23 corresponding to the imaging site. Further, depending on the symptom to be diagnosed, for example, dental caries or root canal treatment, When a high gain with a low X-ray dose and a low image quality is selected, and a low gain with a high X-ray dose and a high image quality is selected for the periodontal disease or cancer and the gain selection switch 6 is pressed, a combination stored in the table 21 in advance is selected. The predetermined irradiation time is determined from among the above, and the X-ray controller 20 is instructed.

Next, when the operator presses the exposure switch 21,
The X-ray controller 20 outputs the irradiation signal corresponding to the X-ray generation period based on the irradiation time of the table 21.
0, and the X-ray generator 10 outputs the irradiation time, X
Generate a line.

When the X-rays reach the image sensor 2 through the subject 1a, charges corresponding to the X-ray image projected on the image sensor 2 are accumulated and output as an image signal after the irradiation is completed.
The image signal from the image sensor 2 is amplified by the gain variable amplifier 3 with a gain instructed by the gain control unit 7, input to the image processing device 4 at the next stage and subjected to predetermined image processing, and then the monitor device 5 and the video printer. An X-ray image is displayed by such as, and is used for diagnosis.

By thus instructing the physique information, the imaged region information and the gain information, it is possible to easily and surely set the appropriate X-ray generation conditions and image processing conditions, and the diagnosability according to the symptoms. It is possible to obtain a good X-ray image of

FIG. 4 is a block diagram showing the electrical construction of an X-ray imaging apparatus which is another embodiment of the present invention. The X-ray imaging apparatus according to the present embodiment has substantially the same configuration as that of FIG. 2 except that the gain selection switch 6 of FIG. 2 is not provided and an image quality selection switch 25 is newly connected to the table 21 and gain control is performed from the table 21. The difference is that the gain signal is transmitted to the unit 7.

For example, as shown in FIG. 5, the image quality selection switch 25 provides a high image quality H which is a high X-ray dose and high resolution image, a medium image quality M which is a standard image quality, and a low X-ray dose and low resolution image. It is composed of panel switches 25a, 25b, and 25c capable of selecting three stages of low image quality L. By pressing one of the panel switches, a desired image quality is selected, and a lamp P on the left side thereof is turned on. Note that the selectable image quality is not limited to three levels, and may be a continuously adjustable one such as a variable volume.

The physique selection switch 22 is, as shown in FIG. 3A, for example, as shown in FIG. 5, panel switches 22a, 22 capable of selecting four stages of pediatric, female, normal and obese.
b, 22c, 22d.

The photographing part selection switch 23 is shown in FIG.
Similar to, for example, as shown in FIG.
No. 1, lower jaw 1 to 3, upper jaw 4 and 5, lower jaw 4 and 5, upper jaw 6 to 8, lower jaw 6 to 8 and occlusion 7 stages respectively Panel switches 23a-2
Composed of 3g.

The table 21 has a total of 84 stages of 4 stages of physique information, 7 stages of imaging region information and 3 stages of image quality information.
The X-ray irradiation time and the gain corresponding to the combination (= 4 × 7 × 3) are stored in advance in a storage element such as a memory,
The X-ray irradiation time determined by inputting each information is instructed to the X-ray controller 20, and the gain determined by inputting each information is instructed to the gain control unit 7. The irradiation time thus determined is displayed on the number display panel 24 shown in FIG. Instead of the table 21, a numerical operation circuit that digitizes each information and performs a predetermined calculation may be used.

The gain control section 7 is composed of a CPU (central processing unit) or the like, and outputs a gain signal to the variable gain amplifier 3 based on the gain signal transmitted from the table 21.

Next, the operation will be described. First, the surgeon looks at the physique of the patient 1 and presses the corresponding physique selection switch 22 and then the imaging site selection switch 23 corresponding to the imaging site. Further, depending on the symptom to be diagnosed, for example, dental caries or root canal treatment, When low image quality L is selected and high image quality H is selected for periodontal disease or cancer and the image quality selection switch 25 is pressed, a predetermined irradiation time and a predetermined gain are determined from the combinations stored in the table 21 in advance. , X-ray controller 20 and gain controller 7, respectively.

Next, when the operator presses the exposure switch 21,
The X-ray controller 20 outputs the irradiation signal corresponding to the X-ray generation period based on the irradiation time of the table 21.
0, and the X-ray generator 10 outputs the irradiation time, X
Generate a line.

When the X-rays reach the image sensor 2 through the subject 1a, charges corresponding to the X-ray image projected on the image sensor 2 are accumulated and output as an image signal after the irradiation is completed.
The image signal from the image sensor 2 is amplified by the gain variable amplifier 3 with a gain instructed by the gain control unit 7, input to the image processing device 4 at the next stage and subjected to predetermined image processing, and then the monitor device 5 and the video printer. An X-ray image is displayed by such as, and is used for diagnosis.

By thus instructing the physique information, the imaged part information and the image quality information, it is possible to easily and surely set the appropriate X-ray generation conditions and image processing conditions, and the diagnosability according to the symptoms. It is possible to obtain a good X-ray image of

[0041]

As described in detail above, according to the present invention, the operator can easily set the appropriate X-ray generation condition and image processing condition by instructing the physique information, the imaging region information, and the gain information or the image quality information. In addition, it is possible to obtain an X-ray image that can be set accurately and reliably and that has a good diagnostic property according to the symptom.

[Brief description of drawings]

FIG. 1 is a usage state diagram of an X-ray imaging apparatus according to the present invention.

FIG. 2 is a block diagram showing an electrical configuration of an X-ray imaging apparatus that is an embodiment of the present invention.

3 (a) is a front view showing an example of a physique selection switch 22 and an imaging region selection switch 23 of FIG. 2, and FIG. 3 (b) is a front view showing an example of a gain selection switch 6 of FIG. It is a figure.

FIG. 4 is a block diagram showing an electrical configuration of an X-ray imaging apparatus which is another embodiment of the present invention.

5 is a front view showing an example of the physique selection switch 22, the imaging part selection switch 23, and the image quality selection switch 25 of FIG.

[Explanation of symbols]

 1 Patient 1a Subject 2 Image sensor 2a Positioning member 3 Gain variable amplifier 4 Image processing device 5 Monitor device 6 Gain selection switch 6a, 6b, 6c Panel switch 7 Gain control unit 10 X-ray generator 11 X-ray irradiation tube 12 Universal arm 15 Exposure switch 20 X-ray control device 21 Table 22 Body size selection switch 22a, 22b, 22c Panel switch 23 Imaging site selection switch 23a-23g Panel switch 24 Numeric display panel 25 Image quality selection switch 25a, 25b, 25c Panel switch

Claims (2)

[Claims] 1. An X-ray generation unit for irradiating a subject with X-rays, an X-ray control unit for controlling an X-ray irradiation time of the X-ray generation unit, and an X-ray image passing through the subject. Image pickup means for picking up the image, an amplifying means for amplifying the signal from the image pickup means with a predetermined gain, and an image processing means for processing the signal from the amplifying means and displaying the X-ray image. An X-ray imaging apparatus including: a physique information selection unit for inputting physique information of a subject; an imaging region information input unit for inputting imaging region information of the subject; and a gain of the amplification unit. Based on the gain information set by the gain setting means for, and the physique information input by the physique information input means, the imaging part information input by the imaging part information input means, and the gain setting part,
An X-ray imaging apparatus comprising: an irradiation time determination unit for determining an X-ray irradiation time of the X-ray generation unit. 2. An X-ray generation means for irradiating a subject with X-rays, an X-ray control means for controlling an X-ray irradiation time of the X-ray generation means, and an X-ray image passing through the subject. Image pickup means for picking up the image, an amplifying means for amplifying the signal from the image pickup means with a predetermined gain, and an image processing means for processing the signal from the amplifying means and displaying the X-ray image. In an X-ray imaging apparatus including: a body size information input unit for inputting body structure information of a subject; an imaged region information input unit for inputting imaged region information of the subject; and an image quality of the X-ray image. Based on the image quality selection unit for selecting, the physique information input by the physique information input unit, the imaging region information input by the imaging region information input unit, and the image quality information selected by the image quality selection unit, X-ray irradiation of the X-ray generation means X-ray imaging apparatus characterized by comprising an irradiation time gain determining means for determining a gain of time and the amplification means.