KR20180089930A - Digital detector with scattered ray filtering function and x-ray imaging system having the same, and module for filtering of scattered rays and x-ray imaging system having the same - Google Patents

Abstract

Disclosed are a digital detector for imaging an X-ray having a scattered ray blocking function and a scattered ray filter module for imaging an X-ray having a scattered ray blocking function. According to one embodiment of the present invention, the digital detector comprises: a case cover (120); a scintillator (130) disposed on a rear side of the case cover (120), receiving an X-ray passing through an object to be detected, and converting the X-ray into visible light; a photodiode module (140) disposed on a rear side of the scintillator (130) and converting the visible light emitted from the scintillator(130) into an electric signal; and a scattered ray filter (170) disposed between the case cover (120) and the scintillator (130) to block scattered rays from the object to be detected.

Description

TECHNICAL FIELD [0001] The present invention relates to a digital detector having a scattering line blocking function, an X-ray imaging system having the scattering line blocking function, a scattering line filter module providing scattering blocking function, and an X- SYSTEM HAVING THE SAME, AND MODULE FOR FILTERING OF SCATTERED RAYS AND X-RAY IMAGING SYSTEM HAVING THE SAME}

The present invention relates to a digital detector having a scattering line blocking function, a scattering line filter module providing a scattering blocking function, and an X-ray imaging system having one of these two configurations.

The X-ray imaging system is a system for obtaining X-ray images of an object to be examined and is applied to various fields such as a medical field.

1 schematically shows a typical X-ray imaging system 10 used for medical diagnosis.

As shown therein, a typical X-ray imaging system 10 includes an X-ray irradiator 1, a body table 2, a digital detector 3, and a grid 4.

The system 10 detects the X-ray irradiated by the X-ray irradiating section 1 toward the inspected object S and the X-ray passed through the inspected object S by the digital detector 3, - It is used in a way to implement the line image.

At this time, some of the components of the X-ray irradiated to the inspected object (S) are scattered by the inspected object (S). Since the scattered rays become background noise in the X-ray image and degrade the image quality, the grid 4 is disposed to attenuate the scattered rays.

In order to compensate for this, the irradiation dose in the X-ray irradiating unit 1 is not limited to the grid 4 because the effective rays for implementing the X- It is necessary to increase the effective dose by the effective dose.

Taking into account that the X-rays have a bad influence on the human body, such an increase in the irradiation dose is not preferable because it involves an increase in the dose of the subject (S).

It is an object of the present invention to provide a method of shielding a scattering line without using a grid in an X-ray imaging system, thereby reducing the cost associated with providing the grid and preventing an increase in irradiation dose due to the application of the grid.

In order to achieve the above object, the present invention provides a digital detector 100 and an X-ray imaging system 200 including the same.

According to one embodiment, the digital detector 100 includes a case cover 120; A scintillator 130 disposed on the rear side of the case cover 120 for receiving X-rays passing through the subject and converting the X-rays into a visible ray; A photodiode module 140 disposed on the rear side of the scintillator 130 for converting visible light emitted from the scintillator into an electric signal; And a scattering line filter 170 disposed between the case cover 120 and the scintillator 130 to block scattered rays from the inspected object.

The scattering line filter 170 may include one blocking sheet 171 or two blocking sheets 171a and 171b for scatter line shielding.

The barrier sheet is made of a material having properties to block X-rays, and may be made of a metal material, for example.

The scattering line filter 170 may further include an electron-absorbing sheet 172 disposed on the rear side of the blocking sheet to absorb electrons generated from the blocking sheet.

The electron absorbing sheet 172 is made of a material having a large molecular weight and absorbing electrons, and can be made of polycarbonate, for example.

In order to achieve the above object, the present invention also provides a scattering line filter module 300 disposed in front of a digital detector and an X-ray imaging system 400 including the same.

According to one embodiment, the scattering line filter module 300 includes the mounting frame 310; And a scattering line filter 320 mounted on the mounting frame 310 to block scattered rays from the subject.

The scattering line filter 320 may include one blocking sheet 321 or two blocking sheets 321a and 321b for scatter line shielding.

The barrier sheet may be made of a metal material.

The scattering line filter 320 may further include an electron-absorbing sheet 322 disposed on the rear side of the blocking sheet to absorb electrons generated from the blocking sheet.

The electron-absorbing sheet 322 is made of a material having a property of absorbing electrons with a large molecular weight, and can be made of, for example, polycarbonate.

1 schematically shows a typical X-ray imaging system 10 used for medical diagnosis.
2 is a schematic cross-sectional view of a digital detector according to an embodiment of the present invention.
3 is a view showing various embodiments of the scattering line filter 170 according to the present invention.
FIG. 4 is a schematic view of an X-ray imaging system 200 according to a first embodiment of the present invention.
5 is a perspective view of a scattering line filter module 300 according to an embodiment of the present invention.
6 is a cross-sectional view of the scattering line filter module 300 taken along line AA '.
7 is a view showing various embodiments of the scattering line filter 320 according to the present invention.
FIG. 8 is a schematic view of an X-ray imaging system 400 according to a second embodiment of the present invention.
9 (a) and 9 (c) are photographs showing an experiment performed to confirm the effect of the present invention. Fig. 9 To embodiments of the present invention.
10A to 10E show the results of the experimental example of FIG. 9 for five tube current amounts.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. Digital detector (100)

2 is a schematic cross-sectional view of a digital detector according to an embodiment of the present invention.

The digital detector 100 according to an embodiment of the present invention includes a case body 110, a case cover 120, a scintillator 130, a photodiode module 140, a TFT panel 150, A circuit board 160 and a scattering line filter 170.

The case body 110 and the case cover 120 form the case of the digital detector 100. For example, the case body 110 may be made of aluminum and the case cover 120 may be made of carbon fiber.

A scintillator 130 is a component that receives X-rays and converts them into light, and is disposed between the scattering line filter 170 and the photodiode module 140.

The photodiode module 140 converts a light generated by the scintillator into an electric signal, and is composed of a plurality of photodiodes.

The TFT panel 150 is for driving the photodiode module 140 and is disposed between the photodiode module 140 and the circuit board 160.

The circuit board 160 performs functions such as signal processing, power supply, and operation control. The circuit board 160 may be composed of one board or may alternatively be composed of a plurality of boards such as a signal processing board (not shown), a power board (not shown), a control board (not shown) .

Although not shown in FIG. 2, an intermediate layer (not shown) may be provided between the TFT panel 150 and the circuit board 160. The intermediate layer is an element for supporting the internal structures of the detector 100, for example, an aluminum panel, which is fastened to the case cover 120 or the case body 110.

The scattering line filter 170 is a filter for blocking scattered rays emitted from the subject.

Here, the scattering line refers to an X-ray component scattered by the subject in the X-rays irradiated by the X-ray irradiating portion. The scattering line has lower energy than the effective line, and it becomes background noise in the X-ray image. Accordingly, when the scattered ray is detected by the photodiode module 140, the quality of the X-ray image is deteriorated, and thus blocking is required.

The digital detector 100 of this embodiment includes a scattering line filter 170 for scattering line blocking between the case cover 120 and the scintillator 130.

The scattering line filter 170 blocks the scattering line having a relatively low energy, and has a property of passing most of the effective X-ray components having a relatively large energy passed through the subject.

Although not shown in FIG. 2, a buffer material (not shown) for absorbing an external shock may be provided between the case cover 120 and the scattering line filter 170. The cushioning material may be made of, for example, a styrofoam material.

3 is a view showing various embodiments of the scattering line filter 170 according to the present invention.

As shown in FIG. 3- (a), the scattering line filter 170 may be composed of only one blocking sheet 171.

The blocking sheet 171 is made of a material having properties that block X-rays. By way of example, the barrier sheet 171 may be made of a material having an atomic weight in the range of between 10 and 30. More specifically, for example, the barrier sheet 171 may be made of a metal material such as aluminum, copper, or the like, or may be made of a non-metallic material such as rubber.

The thickness of the blocking sheet 171 should be selected so that scattering lines of relatively low energy are blocked, but the effective X-ray components of relatively high energy are mostly transmissive. Therefore, when the barrier sheet 171 is made of a metal material, its thickness is preferably selected in the range of 100 to 300 mu m.

As shown in FIG. 3- (b), the scattering line filter 170 may be composed of one blocking sheet 171 and one electron-absorbing sheet 172.

Electrons (primary electrons) are emitted by the Compton Effect in the process of scattering the X-rays irradiated from the X-ray irradiating unit by the subject, and scattered by the blocking sheet 171 The electrons (secondary electrons) are emitted from the blocking sheet 171 by the energy held by the scattering line. These secondary electrons can also be converted to optical components through the scintillator 130, which in turn has an adverse effect on the quality of the X-ray image.

The electron-absorbing sheet 172 absorbs the electrons generated in the blocking sheet 171, thereby preventing the quality of the X-ray image from being lowered by the electrons.

The electron-absorbing sheet 172 is made of a material having the property of absorbing and removing electrons. For example, the electronic absorbent sheet 172 may be made of polycarbonate.

As shown in Fig. 3- (c), the scattering line filter 170 may be composed of two blocking sheets 171a and 171b.

The two barrier sheets 171a and 171b may have the same material and thickness, and at least one of material and thickness may be different.

However, the materials and thicknesses of the respective barrier sheets 171a and 171b should be selected such that the combination of the two barrier sheets 171a and 171b shields the scattering line and allows the effective line to be transmitted.

Like the blocking sheet 171 described above, the blocking sheets 171a and 171b can be made of a metal material (e.g., aluminum, copper) or a non-metallic material (e.g., rubber).

When the blocking sheets 171a and 171b are respectively made of a metal material, the sum of the thicknesses of the two blocking sheets 171a and 171b is preferably selected in the range of 100 to 300 탆.

As shown in Fig. 3- (d), the scattering line filter 170 may be composed of two blocking sheets 171a and 171b and one electron absorbing sheet 172. Fig.

In the embodiments of FIG. 3, the number of barrier sheets constituting the scattering line filter 170 is one or two, but the number of barrier sheets may be three or more.

2. An X-ray imaging system 200 to which a digital detector 100 is applied,

FIG. 4 is a schematic view of an X-ray imaging system 200 according to a first embodiment of the present invention.

The X-ray imaging system 200 according to the first embodiment includes an X-ray irradiator 210, a body table 220, and a digital detector 100.

As such, the X-ray imaging system 200 of this embodiment includes the digital detector 100 described above with reference to Figs. 2 and 3 as a digital detector. As described above, the digital detector 100 is a detector having scattering line blocking function.

In the X-ray imaging system 200 of the present embodiment, the conventional grid 4 as shown in FIG. 1 can be omitted by providing the digital detector 100 having the scattering line blocking function.

Therefore, it is possible to reduce the cost associated with the provision of the grid, and it is not necessary to increase the irradiation dose in order to compensate for the effect of blocking the effective line of the grid, so that the radiation dose of the subject S can be reduced.

In order to maximize the effect of the scattering line filter module which provides the scattering line blocking function, the image of the digital detector can be processed with an appropriate software filter.

3. The scattering line filter module 300,

FIG. 5 is a perspective view of a scattering line filter module 300 according to an embodiment of the present invention, and FIG. 6 is a sectional view taken along line A-A 'of a scattering line filter module 300.

The scattering line filter module 300 shown in FIGS. 5 and 6 is provided in the X-ray imaging system to block scattering lines among the X-ray components emanating from the subject.

The scattering line filter module 300 includes a mounting frame 310 and a scattering line filter 320.

The mounting frame 310 is a part on which the scattering line filter 320 is mounted and supported. According to one embodiment, the support frame 310 may have a substantially frame shape in which the mounting groove 311 is formed along the inner periphery.

The scattering line filter 320 is a component that provides a scattering line blocking function.

The scattering line filter 320 may have the same structure as the scattering line filter 170 of the above-described digital detector 100 shown in FIGS.

Specifically, the scattering line filter 320 may be composed of only one blocking sheet 321 as shown in Fig. 7- (a) and may be constituted by one blocking sheet 321 as shown in Fig. 7- (b) The sheet 321 and the single electron absorbing sheet 322 may be constituted by two blocking sheets 321a and 321b as shown in Fig. 7- (c) , Two blocking sheets 321a and 321b and one electron-absorbing sheet 322 as shown in Fig.

As described in detail in the description of the scattering line filter 170, the blocking sheets 321, 321a, and 321b included in the scattering line filter 320 are configured to perform a scattering line blocking function. The electron-absorbing sheet 322 provided is a structure that performs the function of absorbing the electrons generated in the blocking sheet.

4. An X-ray imaging system 400 to which a scattering line filter module 300 is applied,

FIG. 8 is a schematic view of an X-ray imaging system 400 according to a second embodiment of the present invention.

The X-ray imaging system 400 according to the second embodiment includes an X-ray irradiating unit 410, a subject table 420, a digital detector 430, and a scattering line filter module 300.

In the present embodiment, a conventional general digital detector is applied to the digital detector 430. That is, unlike the digital detector 100 shown in FIG. 2, the digital detector 430 of the present embodiment is not provided with a separate structure for scatter line shielding.

Instead, as shown in FIG. 8, the scattering line filter module 300 is disposed just before the digital detector 430.

As described above, the scattering line filter module 300 functions to block scattering line components coming from the subject S and includes at least one blocking sheet 321, 321a, 321b, (322).

With this scattering line filter module 300, the conventional grid 4 as shown in FIG. 1 is omitted in the X-ray imaging system 400 of the present embodiment.

Therefore, it is possible to reduce the cost associated with the provision of the grid, and it is not necessary to increase the irradiation dose in order to compensate for the effect of blocking the effective line of the grid, so that the radiation dose of the subject S can be reduced.

In order to maximize the effect of the scattering line filter module which provides the scattering line blocking function, the image of the digital detector can be processed with an appropriate software filter.

5. Verification of the effects of the present invention through experiments

Experiments performed by the inventors to verify the effects of the present invention will be described.

9, in this experiment, the tube voltage was kept constant at 75 kVp while the tube current was changed to several values (25.6 mAs, 16 mAs, 12.8 mAs, 10 mAs, 8 mAs) Was performed. 9 (a)), when a scattering line filter (thickness: 0.1 mm) made of aluminum without a grid is disposed in front of the digital detector according to the embodiment of the present invention 9- (b)). X-ray imaging was performed for each of the cases where a copper scatter line filter (thickness 0.1 mm) without a grid was placed in front of the digital detector according to an embodiment of the present invention.

The experimental results are shown in Figs. 10A to 10E.

As shown in FIG. 10A, when the tube current was 25.6 mAs, the Innominate Line, Superior Orbital Fissure and Floor of Sella Turcica were clearly observed in all three cases described above, and bone density Respectively.

As shown in FIG. 10B, when the tube current was 16 mAs, in all three cases, an anomalous wire, a stomach opening and a saddle bottom were observed, but the bone concentration was slightly lowered.

As shown in FIG. 10C, when the tube current was 12.8 mAs, only the anomalous line was observed without a visual clearance and a saddle bottom when the grid was applied, whereas in the embodiments of the present invention in which the aluminum filter or the copper filter was applied, , Upper visual clearance and saddle bottom were observed, and the bone concentration was relatively lower in the case of applying the copper filter than in the case of applying the aluminum filter.

As shown in Fig. 10D, when the tube current was 10 mAs, only an anonymous line was observed when the grid was applied. In the case of the aluminum filter applied example, the anonymous line, the upper clearance and the saddle bottom were observed, In the applied examples, an anonymous line and a saddle bottom were observed, but no clearance was observed clearly.

As shown in FIG. 10E, when the tube current was 10 mAs, no anomalous line, upper visual clearance and saddle bottom were observed when the grid was applied, and in the case of the embodiment where the aluminum filter was applied and in the embodiment where the copper filter was applied, The line and the bottom of the saddle were observed, but no clearance was visible.

The following conclusions can be drawn from the above experimental results.

First, compared to the case where a conventional grid is applied, in the embodiments of the present invention in which an aluminum filter or a copper filter is applied, the quality of the X-ray image is relatively good even at a relatively low tube current, It is concluded that the X-ray dose irradiated on the subject can be greatly reduced by applying the scattering line filter according to the embodiments of the present invention.

Second, the quality of the X-ray image was significantly lowered in copper filter at 10 mAS tube current, whereas the quality of X-ray image was relatively good in aluminum filter. It is more effective to reduce the X-ray dose to be irradiated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that it is possible.

100: Digital detector
110: Case body
120: Case cover
130: scintillator
140: Photodiode module
150: TFT panel
160: Circuit board
170: scattering line filter
171, 171a, 171b:
172: Electron absorption sheet
200: X-ray photographing system (first embodiment)
210: X-ray irradiator
220:
300: scattering line filter module
310: mounting frame
320: scatter line filter
321, 321a, 1b:
322: Electron absorption sheet
400: X-ray imaging system (second embodiment)
410: X-ray irradiator
420: object table
430: Digital detector

Claims (12)

A digital detector (100) for use in an x-ray imaging system,
A case cover 120;
A scintillator 130 disposed on the rear side of the case cover 120 for receiving X-rays passing through the subject and converting the X-rays into visible light;
A photodiode module 140 disposed on the rear side of the scintillator 130 for converting visible light emitted from the scintillator into an electric signal; And
A scattering line filter 170 disposed between the case cover 120 and the scintillator 130 to block scattered rays from the subject;
/ RTI >
Digital detector.
The method according to claim 1,
The scattering line filter (170)
(171) or two blocking sheets (171a, 171b) for scatter line shielding,
Digital detector.
3. The method of claim 2,
Wherein the barrier sheet is made of a metallic material,
Digital detector.
3. The method of claim 2,
The scattering line filter (170)
And an electron-absorbing sheet (172) disposed on the rear side of the blocking sheet to absorb electrons generated from the blocking sheet.
Digital detector.
5. The method of claim 4,
The electron-absorbing sheet 172 is made of polycarbonate,
Digital detector.
An X-ray imaging system (200) for obtaining a digital X-ray image by irradiating X-rays to a subject (S)
A subject table 220 on which the subject S is placed;
An X-ray irradiating unit 210 for irradiating X-rays toward the inspected object S; And
A digital detector (100) according to any one of claims 1 to 5, for receiving an X-ray passing through the inspected object (S) and converting it into a digital electric signal;
/ RTI >
X-ray imaging system.
A scattering line filter module (300) used in front of a digital detector in an X-ray imaging system,
A mounting frame 310; And
A scattering line filter 320 mounted on the mounting frame 310 to block scattered rays from the subject;
/ RTI >
Scatterline filter module.
8. The method of claim 7,
The scattering line filter 320,
Which includes one blocking sheet 321 or two blocking sheets 321a and 321b for scatter line shielding,
Scatterline filter module.
9. The method of claim 8,
Wherein the barrier sheet is made of a metallic material,
Scatterline filter module.
9. The method of claim 8,
The scattering line filter 320,
And an electron-absorbing sheet (322) disposed on the rear side of the blocking sheet to absorb electrons generated from the blocking sheet.
Scatterline filter module.
11. The method of claim 10,
The electron-absorbing sheet 322 is made of polycarbonate,
Scatterline filter module.
An X-ray imaging system (400) for obtaining a digital X-ray image by irradiating X-rays to a subject (S)
A subject table 420 on which the subject S is placed;
An X-ray irradiating part 410 for irradiating X-rays toward the inspected object S; And
A digital detector 430 for receiving X-rays passing through the subject S and converting the X-rays into digital electric signals; And
A scattering line filter module disposed in front of the digital detector (430), comprising: a scattering line filter module (300) according to any one of claims 7 to 11;
/ RTI >
X-ray imaging system.

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