KR20210130483A - Radiation detector for distinguishing and detecting the reaction position of gamma rays and nuclear medicine imaging apparatus comprising the same - Google Patents

Abstract

The present application provides a radiation detector which significantly reduces the manufacturing cost and signal processing time while distinguishing and detecting the reaction position of gamma rays in applying the same to radiation detection in disease diagnosis and radiation accident, etc., and is able to improve the detection accuracy. The radiation detector includes: a scintillator module; an optical filter; an optical guide; a first photodetector; a second photodetector; and a control unit.

Description

Radiation detector for distinguishing and detecting the reaction position of gamma rays and nuclear medicine imaging apparatus comprising the same

The present application relates to a radiation detector that detects by distinguishing reaction positions of gamma rays, and a nuclear medicine imaging apparatus including the same.

A nuclear medical imaging device is a device that generates a quantitative image by administering a radiopharmaceutical tracking a specific lesion into the human body. In order to improve the performance of nuclear medical imaging devices, it is necessary to increase the image quality while reducing the exposure dose.

In order to increase the sensitivity of the device, it is necessary to detect a lot of radiation at the same time and inevitably use a scintillator with a long decay time. However, when a scintillator with a long length is used, it does not matter if the radiation comes from the center, but when the radiation comes from another direction, it is difficult to determine where the radiation is detected, so there is uncertainty as much as the length of the scintillator. It is called (Parallax error), and there was a problem in that the image quality was deteriorated due to a parallax error.

In order to solve the above problems, in the prior art, a depth of interaction (DOI) and a time of flight (TOF) were applied.

In the conventional Depth of Interaction (DOI) method, a scintillator having a fast decay time and a scintillator having a slow decay time are configured to distinguish a different arrangement from the pulse shape discrimination (PSD) method, which is distinguished by a difference in signal shape. An off-set method is known that is composed of a scintillator or a shape to distinguish it by varying the degree or shape of the spread of the light generated from the scintillator.

However, pulse shape discrimination (PSD) requires the use of a high-speed analog-to-digital converter (ADC) and an algorithm for differentiating the waveform, but the signal processing speed and cost problems in the circuit and computer There is a disadvantage in that the time resolution is lowered because the attenuation time of the scintillators must be different from each other.

In addition, the off-set method requires a complex algorithm such as a center of gravity (COF) algorithm in order to specify a reacting scintillator, and there is a problem in that the cost due to processing and housing of the scintillator increases.

And, the time of flight (TOF) is a method that can increase the image quality while lowering the exposure amount by reducing the uncertainty about the location of the gamma ray generation by measuring the irregular time of the gamma ray.

On the other hand, conventional nuclear medicine devices have introduced a Phoswich detector (also referred to as a 'sandwich detector') in order to apply the above-described reaction depth discrimination method and irregular time discrimination method.

In general, a four-switch detector is a detector developed to detect low-level, low-energy gamma rays and X-rays as well as alpha particles and beta particles in a high-energy radiation environment. Such a four-switch detector can simultaneously process and distinguish all energy-specific radiations that are incident according to a structural form.

The name 'Phoswich' is a term derived from Phosphor sandwich, and two or more scintillators with different characteristics, such as different waveforms, are optically connected to each other to form a photodiode, APD (Avalanche photodiode), SiPM (Silicon photomultiplier). , silicon photomultiplier), PMT (photomultiplier tube, photomultiplier tube) refers to a structure combined with an optical sensor. Signals that incident radiation reacted to a specific scintillator can be distinguished by techniques such as waveform analysis.

The four-switch detector uses two or more different scintillators in front and rear or in a stacked structure to discriminate based on the transmittance of radiation and the presence or absence of reaction with the scintillator. There are many ways to distinguish the scintillator, the most representative example is using the decay time of the signal. For example, one scintillator is configured to have a fast decay time performance and the other scintillator has a slow decay time performance, and thus is distinguished by a difference in signal shape.

1 is a diagram of a four-switch detector using a conventional optical filter.

As shown in FIG. 1, the conventional four-switch detector using an optical filter (or cut-off filter) inserts an optical filter in each layer of the same scintillator, divides it into two wavelength bands, and determines the position by the difference in the signal entering the optical sensor. . 1, the conventional four-switch detector inserts a short-wavelength optical filter 21 that blocks a wavelength of 450 nm or less between the upper scintillator 11 and the lower scintillator 12 layer, and a long-wavelength optical filter that blocks a wavelength of 450 nm or more It is constructed by inserting the filter 22 into the lower scintillator 12 and the optical sensor 30 . For example, assuming that the wavelength of 450 nm is half the amount of light, the light generated from the upper scintillator 11 reaches 0 in the channel A 31 and 0.5 in the channel B 32, and in the lower scintillator 12 The generated light reaches 0.5 to the channel A 31 and 1 to the channel B 32 . The structure does not require complicated algorithms and has excellent temporal resolution. However, the loss of the amount of light generated by the scintillator is large, so the energy resolution is reduced, which leads to deterioration of image quality.

The present application has been devised to solve the problems of the prior art as described above, and when applied to a nuclear medicine imaging apparatus, a radiation detector capable of accurately and rapidly discriminating the reaction position of gamma rays and improving image quality while reducing the amount of exposure An object of the present invention is to provide a nuclear medicine imaging device.

In order to solve the above problem, in a radiation detector for detecting and discriminating reaction positions of gamma rays, a first scintillator that reacts with gamma rays to emit light in a first wavelength band and a second wavelength band different from the first wavelength band by reacting with gamma rays a scintillator module formed by stacking a second scintillator that emits light; an optical filter attached to a region of the scintillator module to partially or completely block any one of the light of the first wavelength band or the second wavelength band; a light guide attached to another area of the scintillator module to transmit light in first and second wavelength bands; a first photodetector attached to any one of the optical filter or the light guide, and generating a _{first detection signal (S 1 ) by detecting light passing through the attached optical filter or light guide;} Doedoe attached to any one of the optical filter or light guide, attached to the first photodetector and the other, and detects the light passing through the attached optical filter or light guide to generate a _{second detection signal (S 2 )} a second photodetector; and a control unit for determining a reaction position of gamma rays based on the first and second detection signals.

The radiation detector according to the present application uses an optical filter that selectively blocks some or all of the light emitted from a specific scintillator and a light guide that transmits the light emitted from the specific scintillator, thereby significantly simplifying the circuit configuration and signal processing process. It has the advantage of more accurately determining the reaction position of gamma rays.

And, it is applied to the reaction depth determination method and the irregular time determination method of the nuclear medicine imaging apparatus, thereby improving image quality and reducing the amount of exposure.

In addition, since it consists of a simple circuit configuration, reduction in equipment cost and improvement in processing speed can be expected.

Finally, it is possible to achieve miniaturization of the device by simplifying the detector structure.

1 is a view showing a conventional four-switch detector using an optical filter.
2 is a view showing a radiation detector according to an embodiment of the present invention.
3 and 4 relate to an exemplary radiation detector in which an optical filter blocks light emitted from a first scintillator.
5 is a view showing first and second detection signals generated by the first and second photodetectors, respectively, and a fixed discriminant value generated through a comparator, when the detectors shown in FIGS. 3 and 4 are in an operating state; FIG. am.
6 and 7 are diagrams illustrating ratios of first and second detection signals when the detectors shown in FIGS. 3 and 4 are in an operating state.
8 and 9 relate to an exemplary radiation detector in which an optical filter blocks light emitted from a second scintillator.
FIG. 10 is a view showing first and second detection signals generated by the first and second photodetectors, respectively, and a fixed discriminant value generated through a comparator, when the detectors shown in FIGS. 8 and 9 are in an operating state; FIG. am.
11 is a diagram illustrating ratios of first and second detection signals when the detectors shown in FIGS. 8 and 9 are in an operating state.
12 and 13 are views respectively illustrating structures in which the stacking order of the first scintillator and the second scintillator is different in the detector shown in FIGS. 3 and 4 .
14 is a view showing first and second detection signals generated by the first and second photodetectors, respectively, and a fixed discriminant value generated through a comparator, when the detectors shown in FIGS. 12 and 13 are in an operating state; FIG. am.
15 is a diagram illustrating ratios of first and second detection signals when the detectors shown in FIGS. 13 and 14 are in an operating state.
16 to 18 are views showing various arrangement structures of the optical filter, the light guide, and the first and second detectors in the detector shown in FIG. 2 .
19 and 20 are diagrams exemplarily showing a radiation detector including three scintillators.
21 is a diagram illustrating an arrangement state for various area ratios of an optical filter in a single radiation detector.
Fig. 22 is a diagram showing the arrangement state when the area ratio of the optical filter in the radiation detector array is 50%.
23 to 28 are diagrams illustrating exemplary structures of a radiation detector including an optical filter module.

Hereinafter, a radiation detector according to the present invention will be described in detail with reference to the embodiments shown in the drawings.

2 is a view showing a radiation detector according to an embodiment of the present invention.

Referring to the drawings, the radiation detector according to an embodiment of the present invention detects by distinguishing the reaction position of gamma rays, and specifically, the scintillator module 100, the optical filter 200, the light guide 300, the second It includes a first photodetector 400 , a second photodetector 500 , and a controller 600 .

The scintillator module 100 includes a first scintillator 110 that emits light in a first wavelength band in response to gamma rays and a second scintillator 120 that reacts with gamma rays and emits light in a second wavelength band different from the first wavelength band. are stacked and formed. The first wavelength band and the second wavelength band may be in the visible light region, for example, in the 400 to 700 nm wavelength band. In addition, the first wavelength band and the second wavelength band may not overlap all of the wavelength region, or only the main wavelength region may not overlap.

The optical filter 200 is attached to one region of the scintillation module to partially or completely block any one of the light of the first wavelength band or the second wavelength band. Here, "partially blocked" means that a part is blocked and a part is transmitted. For example, when the amount of light emitted from the scintillator is 100%, the amount of light partially blocked by the optical filter 200 is 90% or less, 80% or less, 70% or less, 60% or less, or 50% or less. On the other hand, when the amount of light emitted from the scintillator is 100%, “block all” means that the amount of light transmitted through the optical filter 200 is 0%. The optical filter 200 may be directly coated on the scintillator in the scintillation module or directly coated on the photodetector. As another example, the optical filter 200 may be coated on a separate substrate and inserted between the scintillator and the photodetector. In addition, the material of the optical filter 200 is not particularly limited, and a known optical filter 200 capable of blocking light in a specific wavelength band may be used. The optical filter 200 may block light of a specific wavelength band and transmit light other than the blocked wavelength band.

In addition, the light guide 300 is attached to another area of the scintillator module 100 to transmit light in the first and second wavelength bands. The material of the light guide 300 may be glass. The light guide 300 may transmit light in all bands as well as in the first and second wavelength bands.

The first photodetector 400 is attached to any one of the optical filter 200 or the light guide 300 , and detects the light passing through the attached optical filter 200 or the light guide 300 , A detection signal S1 is generated. In addition, the second photodetector 500 is attached to any one of the optical filter 200 or the light guide 300 , is attached to the other one from the first photodetector 400 , and is attached to the optical filter 200 . ) or the light passing through the light guide 300 is sensed to generate a second detection signal S2. For example, the first photodetector 400 may be attached to the optical filter 200 , and the second photodetector 500 may be attached to the light guide 300 . Conversely, the first photodetector 400 may be attached to the light guide 300 , and the second photodetector 500 may be attached to the optical filter 200 .

The first and second photodetectors 500 are optical sensors that generate a signal by sensing a waveform and amount of light, and various known devices may be used, for example, DSiPM (Digital SiPM), a photomultiplier tube ( PMT/Photo Multiplier Tube), silicon photomultiplier tube (SiPM/Silicon Photomultiplier), photodiode, and avalanche photodiode (APD/Avalanche Photodiode) may be exemplified.

The intensity of the first and second detection signals S1 and S2 generated by the first and second photodetectors 500 is determined in proportion to the amount of transmitted light. That is, the greater the amount of transmitted light, the greater the intensity of the sensing signal.

Then, the control unit 600 determines the reaction position of the gamma ray based on the first and second detection signals. The controller 600 may determine whether the scintillator to which the gamma ray is incident is the first scintillator 110 or the second scintillator 120 based on the first and second detection signals.

The control unit 600 controls the response position of gamma rays according to the wavelength band blocked by the optical filter 200, the stacked structure of the first and second scintillators 110 and 120, and the ratio of the first and second detection signals. can be identified. Hereinafter, various cases of the radiation detector according to the present application will be described with reference to the drawings.

3 and 4 relate to an exemplary radiation detector in which an optical filter blocks light emitted from a first scintillator.

Specifically, FIG. 3 is a view showing an operating state in which gamma rays are incident to the first scintillator 110 in a detector including an optical filter 200 for blocking light emitted from the first scintillator 110, FIG. 4 is a diagram illustrating an operating state in which gamma rays are incident on the second scintillator 120 in the detector including the optical filter 200 for blocking the light emitted from the first scintillator 110 .

Referring to FIG. 3 , it can be seen that the light of the first wavelength band emitted from the first scintillator 110 is blocked by the optical filter 200 , while passing through the light guide 300 . And, referring to FIG. 4 , it can be confirmed that the light of the second wavelength band emitted from the second scintillator 120 passes through the optical filter 200 and the light guide 300 .

5 is a view showing first and second detection signals generated by the first and second photodetectors, respectively, and a fixed discriminant value generated through a comparator, when the detectors shown in FIGS. 3 and 4 are in an operating state; FIG. am.

Case 1 of FIG. 5 is a case in which light of a first wavelength band is emitted from the first scintillator 110 , and in this case, the first and second detection signals generated by the first and second photodetectors 500 are shown. Case 2 of FIG. 5 is a case in which light in the second wavelength band is emitted from the second scintillator 12 0 , and in this case, the first and second detection signals generated by the first and second photodetectors 400 and 500 are detected. indicates.

6 and 7 are diagrams illustrating ratios of first and second detection signals when the detectors shown in FIGS. 3 and 4 are in an operating state. Specifically, FIG. 6 shows the ratio (S1/S2) of the first detection signal to the second detection signal when the detector shown in FIGS. 3 and 4 is in operation, and FIG. 7 is shown in FIGS. 3 and 4 It represents the ratio (S2/S1) of the second detection signal to the first detection signal when the illustrated detector is in an operating state.

In one example, the controller 600 may determine the response position of the gamma ray based on the ratio of the first and second detection signals. For example, the control unit 600 responds to gamma rays through a ratio of the first detection signal to the second detection signal (S1/S2) or a ratio of the second detection signal to the first detection signal (S2/S1). location can be determined.

Referring to FIG. 6 , when the ratio (S1/S2) of the first detection signal to the second detection signal is relatively low, the controller 600 may determine the response position of the gamma rays as the first scintillator 110 . . In addition, when the ratio (S1/S2) of the first detection signal to the second detection signal is relatively high, the reaction position of the gamma rays may be determined as the second scintillator 120 .

Conversely, referring to FIG. 7 , when the ratio (S2/S1) of the second detection signal to the first detection signal is relatively low, the control unit 600 determines the reaction position of the gamma rays as the second scintillator 120 . can In addition, when the ratio of the first detection signal to the second detection signal (S2/S1) is relatively high, the reaction position of the gamma rays may be determined as the first scintillator 110 .

8 and 9 relate to an exemplary radiation detector in which an optical filter blocks light emitted from a second scintillator.

Specifically, FIG. 8 is a view showing an operating state in which gamma rays are incident to the first scintillator 110 in a detector including an optical filter 200 for blocking light emitted from the second scintillator 120, FIG. 9 is a diagram illustrating an operating state in which gamma rays are incident to the second scintillator 120 in the detector including the optical filter 200 for blocking the light emitted from the second scintillator 120 .

Referring to FIG. 8 , it can be confirmed that the light of the first wavelength band emitted from the first scintillator 110 passes through the optical filter 200 and the light guide 300 . And, referring to FIG. 9 , it can be seen that the light of the second wavelength band emitted from the second scintillator 120 is blocked by the optical filter 200 , while passing through the light guide 300 .

FIG. 10 is a view showing first and second detection signals generated by the first and second photodetectors, respectively, and a fixed discriminant value generated through a comparator, when the detectors shown in FIGS. 8 and 9 are in an operating state; FIG. am.

Case 1 of FIG. 10 is a case in which light of a first wavelength band is emitted from the first scintillator 110 , and in this case, the first and second detection signals generated by the first and second photodetectors 500 are shown. Case 2 of FIG. 10 is a case in which light in the second wavelength band is emitted from the second scintillator 120 , and in this case, the first and second detection signals generated by the first and second photodetectors 400 and 500 are shown. .

11 is a diagram illustrating ratios of first and second detection signals when the detectors shown in FIGS. 8 and 9 are in an operating state. Specifically, FIG. 13 shows the ratio (S2/S1) of the second detection signal to the first detection signal.

Referring to FIG. 11 , when the optical filter 200 blocks the light of the second scintillator 120 , the controller 600 determines that the ratio (S1/S2) of the first detection signal to the second detection signal is relatively low. In this case, the reaction position of the gamma rays may be determined as the second scintillator 120 . In addition, when the ratio of the first detection signal to the second detection signal (S1/S2) is relatively high, the gamma-ray reaction position may be determined as the first scintillator 110 . When the optical filter 200 blocks the light of the second scintillator 120, although not shown in the drawing, the controller 600 determines that the ratio (S2/S1) of the second detection signal to the first detection signal is relative. is low, the reaction position of the gamma rays may be determined as the first scintillator 110 . In addition, when the ratio (S2/S1) of the second detection signal to the first detection signal is relatively high, the reaction position of the gamma rays may be determined as the second scintillator 120 .

12 and 13 are views respectively illustrating structures in which the stacking order of the first scintillator and the second scintillator is different in the detector shown in FIGS. 3 and 4 .

Specifically, FIGS. 3 and 4 are views showing a structure in which the first scintillator 110 is on the top and the second scintillator 120 is stacked on the bottom, and FIGS. 12 and 13 are the second scintillator 120 on the top. and a diagram showing a structure stacked on the lower portion of the first scintillator 110 .

14 shows first and second detection signals generated by the first and second photodetectors 500, respectively, and a fixed discriminant value generated through a comparator, respectively, when the detectors shown in FIGS. 12 and 13 are in an operating state. is a diagram showing

Case 1 of FIG. 14 is a case in which light in the second wavelength band is emitted from the second scintillator 120, and in this case, the first and second detection signals generated by the first and second photodetectors 400 and 500 are shown. . Case 2 of FIG. 14 is a case in which light in the first wavelength band is emitted from the first scintillator 110 , and in this case, the first and second detection signals generated by the first and second photodetectors 400 and 500 are shown. .

15 is a diagram illustrating ratios of first and second detection signals when the detectors shown in FIGS. 13 and 14 are in an operating state. Specifically, FIG. 15 shows the ratio (S2/S1) of the second detection signal to the first detection signal.

15, the second scintillator 120 has a structure in which the upper part and the first scintillator 110 are stacked on the lower part, and the optical filter 200 blocks the light of the second wavelength band of the second scintillator 120. In this case, when the ratio (S2/S1) of the second detection signal to the first detection signal is relatively low, the controller 600 may determine the response position of the gamma rays as the second scintillator 120 . In addition, when the ratio (S2/S1) of the second detection signal to the first detection signal is relatively high, the reaction position of the gamma rays may be determined as the first scintillator 110 .

In one embodiment, a comparator for generating a fixed discrimination value by comparing the amount of light detected by the first photodetector 400 with a predetermined reference value may be further included. For example, the comparator generates a discrimination value of '0' when the amount of light detected by the first photodetector 400 is less than or equal to a predetermined reference value, and the amount of light detected by the first photodetector 400 . When this predetermined reference value or more, a discriminant value of '1' may be generated.

The controller 600 may determine the reaction position of the gamma ray through the fixed discrimination value generated by the comparator. The control unit 600 determines the reaction position of gamma rays from the fixed discriminant value in consideration of the stacked structure of the first and second scintillators 110 and 120 and the wavelength band of light blocked by the optical filter 200 . can For the specific fixed discriminant value and thus the determination of the reaction position of gamma rays, refer to FIGS. 5, 10 and 14 .

In one embodiment, the first scintillator 110 and the second scintillator 200 are not particularly limited as long as they are materials that react with gamma rays and emit light in different wavelength bands. For example, the first and second scintillators ( 110, 120) is CaF2(Eu), CsI(Na), LYSO, LSO, NaI(TI), LaBr3, BaF2, LuAG:Pr, GPS, YAP:Ce, GSO, Ce:GAGG, Ce:GFAG, LuAg: Ce, CsI (TI), and may be different scintillators selected from the group consisting of YAG:Ce, but is not limited thereto, and various known scintillators may be used. In the above, CaF2(Eu), CsI(Na), LYSO, LSO, NaI(TI), LaBr3, BaF2, LuAG:Pr, GPS, YAP:Ce and GSO may be short-wavelength scintillators, Ce:GAGG, Ce: GFAG, LuAg:Ce, CsI(TI) and YAG:Ce may be long-wavelength scintillators.

Meanwhile, hereinafter, FIGS. 16 to 18 are views showing various arrangement structures of the optical filter, the light guide, and the first and second detectors in the detector shown in FIG. 2 .

First, in the radiation detector according to the embodiment shown in FIG. 2 , the optical filter 200 and the light guide 300 are attached to the surface opposite to the first scintillator 110 of the second scintillator 120 as an example. On the other hand, in the radiation detector shown in FIG. 16 , the optical filter 200 is attached to the surface opposite to the second scintillator 120 of the first scintillator 110 , and the light guide 300 is attached to the second scintillator 120 . The first scintillator 110 is exemplified by being attached to the opposite surface. And the first photodetector 400 is located at the rear end of the optical filter 200, is disposed at the rear end of the light guide 300, from the bottom of FIG. 16, the second photodetector 500, the light guide 300, the second For example, the scintillator 120 , the first scintillator 110 , the optical filter 200 , and the first photodetector 400 are sequentially stacked.

The radiation detector shown in FIG. 17 exemplifies that the optical filter 200 and the light guide 300 are attached to one side of the first scintillator 110 and the second scintillator 120 in the stacking direction. In FIG. 17 , it is exemplified that the optical filter 200 is attached to one side of the first scintillator 110 and the light guide is attached to one side of the second scintillator 120 . In addition, it is exemplified that the first photodetector 400 and the second photodetector 500 are disposed on side surfaces of the optical filter 200 and the light guide 300 , respectively.

The radiation detector shown in FIG. 18 exemplifies that the optical filter 200 and the light guide 300 are dispersedly installed on both sides of the first scintillator 110 and the second scintillator 120 in the stacking direction. Specifically, in FIG. 18 , the optical filter 200 is attached to one side of the first scintillator 110 and the second scintillator 120 in the stacking direction, and the light guide 300 is the first and second scintillators. It is exemplified that the scintillators 110 and 120 are attached and formed on the other side in the stacking direction. More specifically, in FIG. 18 , the optical filter 200 is attached over one side surface of the first scintillator 110 and the second scintillator 120 , and the light guide 300 includes the first scintillator 110 and the second scintillator 110 . As an example, it is attached over the other side surface of the 2 scintillator 120 . In addition, it is exemplified that the first photodetector 400 and the second photodetector 500 are disposed on side surfaces of the optical filter 200 and the light guide 300 , respectively.

On the other hand, the radiation detector according to the present application may be composed of three or more scintillators, an optical filter and a light guide accordingly, and specific examples thereof are shown in FIGS. 19 and 20 .

The radiation detectors shown in FIGS. 19 and 20 include a first scintillator 110, a second scintillator 200, a third scintillator 130, a first optical filter 200, a second optical filter 800, and a light guide ( 300 ), a first photodetector 400 , a second photodetector 500 , and a third photodetector 700 .

Specifically, the radiation detector shown in FIG. 19 is an expanded form of the arrangement structure of FIG. 2 , and the arrangement structure of the radiation detector shown in FIG. 20 is an extended form of FIG. 17 .

In addition, in the various arrangement structures of FIGS. 16 to 20 , the position of the scintillator may be changed, and the wavelength band of light blocked by the optical filter 200 may also be changed.

FIG. 21 is a diagram illustrating an arrangement state for various area ratios of an optical filter in a single radiation detector, and FIG. 22 is a diagram illustrating an arrangement state when an area ratio of an optical filter is 50% in a radiation detector array.

21 and 22 , the radiation detector according to the present application may adjust the amount of light transmitted through the optical filter 200 based on the cross-sectional area ratio of the scintillation body module and the optical filter 200 . 21 (a) is a case in which the cross-sectional area ratio of the optical filter 200 to the scintillator module 100 occupies 50%, and FIG. 21 (b) shows the optical filter 200 to the scintillator module 100. %, and Fig. 21 (c) corresponds to a case where the ratio of the cross-sectional area of the optical filter 200 to the scintillator module 100 occupies 10%.

In addition, when the radiation detector according to the present application is a plurality of connected radiation detector arrays, the ratio of the cross-sectional area of the optical filter 200 to the scintillator module 100 corresponds to 50% when arranged as shown in FIG. 22 .

The present application relates to a radiation detector having a structure different from the aforementioned radiation detector. The radiation detector has a structure different from the aforementioned radiation detector in that an optical filter module including an optical filter 210 and a first light guide 220 is provided.

23 to 28 are diagrams illustrating exemplary structures of a radiation detector including an optical filter module. Specifically, the radiation detector illustrated in FIG. 23 is a diagram illustrating another embodiment of the radiation detector illustrated in FIG. 2 , and the radiation detector illustrated in FIG. 24 is a diagram illustrating another embodiment of the radiation detector illustrated in FIG. 16 . , the radiation detector shown in FIG. 25 is a diagram showing another embodiment of the radiation detector shown in FIG. 17 , the radiation detector shown in FIG. 26 is a diagram showing another embodiment of the radiation detector shown in FIG. 18 , and FIG. The radiation detector illustrated in FIG. 27 is a diagram illustrating another embodiment of the radiation detector illustrated in FIG. 19 , and the radiation detector illustrated in FIG. 28 is a diagram illustrating another embodiment of the radiation detector illustrated in FIG. 20 .

Referring to the drawings, the radiation detector includes a scintillator module 100 , an optical filter module, a second light guide 300 , a first photodetector 400 , a second photodetector 500 , and a controller 600 . . Since the second light guide is the same as the above-described light guide, the same reference numerals are used. The optical filter module is attached to an area of the scintillator module 100 to partially or completely block any one of the first and second wavelength bands of light, the optical filter 210, and the first and second wavelengths. and a first light guide 220 that transmits light in a wavelength band. A detailed description of the optical filter 210 is the same as that described above, and thus will be omitted below. In addition, the roles of the first light guide 220 and the second light guide 300 are the same as those of the light guide 300 described above, and detailed descriptions of the scintillator module 100 , the light detector and the control unit 600 are Since it overlaps with the above, it will be omitted below.

As the optical filter module includes the optical filter 210 and the first light guide 220 together, it has an advantage that the amount of light emitted from the scintillator reaches the photo detector is more effective.

The present application also relates to a nuclear medical imaging device. The nuclear medicine imaging apparatus applies the above-described radiation detector to the reaction depth determination method and the irregular time determination method. Such a device may be, for example, a positron emission tomography (PET).

Since the nuclear medical imaging apparatus including the above-described radiation detector does not require a complex algorithm required for the conventional reaction depth determination method and non-stationary time determination method, it is advantageous in terms of cost and signal processing speed and has the advantage of providing excellent image quality. .

As described above, although the present application has been described with reference to limited embodiments and drawings, the present application is not limited thereto, and various modifications and variations may be possible.

100: scintillator module
110: first scintillator
120: second scintillator
200: optical filter
300: light guide
400: first photodetector
500: second photodetector
600: control unit

Claims (11)

In the radiation detector for discriminating and detecting the reaction position of gamma rays,
a scintillator module formed by stacking a first scintillator that reacts with gamma rays to emit light in a first wavelength band and a second scintillator that reacts with gamma rays to emit light in a second wavelength band different from the first wavelength band;
an optical filter attached to a region of the scintillator module to partially or completely block any one of the light of the first wavelength band or the second wavelength band;
a light guide attached to another area of the scintillator module to transmit light in first and second wavelength bands;
a first photodetector attached to any one of the optical filter or the light guide, and generating a _{first detection signal (S 1 ) by detecting light passing through the attached optical filter or light guide;}
Doedoe attached to any one of the optical filter or light guide, attached to the first photodetector and the other, and detects the light passing through the attached optical filter or light guide to generate a _{second detection signal (S 2 )} a second photodetector; and
and a control unit for determining a reaction position of gamma rays based on the first and second detection signals. The radiation detector according to claim 1, wherein the control unit determines a reaction position of gamma rays based on ratios of first and second detection signals. The radiation detector of claim 1 , further comprising: a comparator configured to compare an amount of light sensed by the first photodetector with a predetermined reference value to generate a fixed discriminant value. The radiation detector according to claim 3, wherein the control unit determines the reaction position of the gamma ray through the fixed discrimination value generated by the comparator. The method of claim 1, wherein the first and second scintillators are CaF2(Eu), CsI(Na), LYSO, LSO, NaI(TI), LaBr3, BaF2, LuAG:Pr, GPS, YAP:Ce, GSO, Ce A radiation detector comprising different scintillators selected from the group consisting of :GAGG, Ce:GFAG, LuAg:Ce, CsI(TI) and YAG:Ce. The radiation detector of claim 1 , wherein the optical filter and light guide are formed attached to a surface of the second scintillator opposite the first scintillator. The method of claim 1, wherein the optical filter is formed by attaching to a surface opposite to the second scintillator of the first scintillator,
wherein the light guide is formed attached to a surface of the second scintillator opposite the first scintillator. The radiation detector according to claim 1, wherein the optical filter and the light guide are attached to one side of the first scintillator and the second scintillator in the stacking direction. The method of claim 1, wherein the optical filter is attached to one side of the first and second scintillators in the stacking direction,
and the light guide is formed to be attached to the other side of the first and second scintillators in a stacking direction. In the radiation detector for discriminating and detecting the reaction position of gamma rays,
a scintillator module formed by stacking a first scintillator that reacts with gamma rays to emit light in a first wavelength band and a second scintillator that reacts with gamma rays to emit light in a second wavelength band different from the first wavelength band;
An optical filter attached to a region of the scintillator module to partially or completely block any one of the light of the first and second wavelength bands, and a first light guide that transmits the light of the first and second wavelength bands. an optical filter module comprising;
a second light guide attached to another area of the scintillator module to transmit light in first and second wavelength bands;
a first photodetector attached to any one of the optical filter module or the second light guide and generating a _{first detection signal (S 1 ) by detecting light passing through the attached optical filter module or the second light guide;}
A second detection signal ( a second photodetector that produces S _{2 );} and
and a control unit for determining a reaction position of gamma rays based on the detection signals of the first and second photodetectors. A nuclear medical imaging device comprising a radiation detector according to claim 1 or 10 .

Images