KR20210089439A - Interaction depth measurement method and interaction depth measurement device of gamma radiation for radiation detector based on energy separation - Google Patents

Abstract

The present invention relates to a radiation (gamma radiation) reaction depth measurement method and a radiation (gamma radiation) reaction depth measurement device for a radiation detector based on energy separation, which can improve spatial resolution by measuring a position at which a scintillator and radiation interact with each other in a radiation detector such as a positron emission tomography apparatus, thereby promoting resolution improvement of a system or equipment having improved resolution. According to the present invention, the radiation reaction depth measurement device for a radiation detector is a device for measuring the reaction depth of radiation in a radiation detector and comprises: a scintillator module configured to generate different signals for radiation; a light sensor module acquiring a generation signal generated by the scintillator module; and a reaction depth measurement module extracting a position at which a scintillator and radiation react based on the generation signal acquired by the light sensor module to measure the reaction depth of radiation.

Description

INTERACTION DEPTH MEASUREMENT METHOD AND INTERACTION DEPTH MEASUREMENT DEVICE OF GAMMA RADIATION FOR RADIATION DETECTOR BASED ON ENERGY SEPARATION

The present invention relates to a radiation (gamma-ray) response depth measurement method for a radiation detection device and a radiation (gamma-ray) response depth measurement device, and more particularly, to a location where a scintillator and radiation interact in a radiation detection device such as a positron emission tomography device A radiation (gamma-ray) response depth measurement method and radiation (gamma-ray) response for a radiation detection device based on energy separation that can improve spatial resolution by measuring It relates to a depth measuring device.

The present invention can be applied to a radiation detection device, and in the description of the background art below, a positron emission tomography apparatus, which is an example of a radiation detection device, will be described as an example.

In general, Positron Emission Tomography (PET) detects a pair of gamma rays generated when positrons of a radioactive material injected into the human body collide with neighboring electrons, and enters the body inside the body through the detection position of the gamma rays. It is a tomography device that acquires a three-dimensional tomography image of Korea.

The positron emission tomography apparatus as described above is largely divided into a detection means and an imaging device. In this case, in the case of the detection means, a plurality of detector modules are radially disposed to form a detection ring, Gamma rays are detected through a plurality of detector modules.

PET equipment is equipped with a radiation detector module that receives incident gamma rays and converts them into electrical signals while reflecting the incident position and energy of the gamma rays when acquiring a tomography image, which is classified into a scintillation camera or a semiconductor detector.

A scintillation camera consists of a scintillator composed of NaI crystals, BGO or LSO, and a photo multiplier tube (PMT). Gamma rays incident on the scintillator are converted into an optical signal, and the optical signal is converted into a photomultiplier tube. converted into an electrical signal by

The semiconductor detector is constituted by arranging a plurality of semiconductor detection elements such as CdTe or CdZnTe that generate electric charges due to the incident of gamma rays in a planar area (matrix shape) and discretely.

However, in the conventional radiation detector as described above, when a tomographic image is acquired by a PET device, there is a problem in that spatial resolution is deteriorated due to gamma rays incident obliquely on the surface of the detector module outside the measurement field of view. A technique for measuring the gamma-ray response depth in a radiation detector is needed.

On the other hand, the current PET detector development trend for small animals can be divided into a group targeting high resolution and a group targeting high sensitivity. For high sensitivity, the best method is to use a block-type scintillation crystal.

In the case of high resolution, improving the x and y-axis resolution of the detector to within 2 mm is meaningless because of the distance that positrons travel before they emit extinction gamma rays.

Specifically, a positron emission tomography apparatus for small animals uses a small gantry and a thin and long scintillator to improve sensitivity and spatial resolution. Gamma cameras used in radiation monitoring systems and environmental monitoring systems use pinhole collimators and diffusion collimators to capture a wide range with a small gamma camera.

In such a system, since gamma rays generated outside the field of interest are obliquely incident on the scintillator, the spatial resolution deteriorates. The degradation of spatial resolution can be solved by measuring the reaction depth at which radiation interacts within the scintillator.

A method of measuring the reaction depth of radiation according to the prior art will be described with reference to a schematic diagram as follows.

1 is a diagram schematically showing the configuration of a radiation (gamma ray) measuring module according to a first embodiment of the related art, and FIG. 2 is a graph showing the difference in attenuation time in each scintillator layer by the detector according to FIG. 1 and 2, different types of scintillators or the same type of scintillator are stacked in several layers and the reaction depth is measured using the difference in the decay time of the scintillators of each layer.

3 is a diagram schematically showing the configuration of a measurement module for measuring a radiation (gamma-ray) response depth according to a second embodiment of the prior art. By placing optical sensors at both ends of the scintillator, the light signal generated from the scintillator is obtained from each optical sensor. The depth of the reaction is measured by the ratio.

4 is a diagram schematically showing the configuration of a measurement module for measuring a radiation (gamma-ray) response depth according to a third embodiment of the prior art. A position where a gamma-ray reacts by using a scintillator of several layers and positioning an optical sensor for each layer will be measured directly.

5 is a diagram schematically showing the configuration of a measurement module for measuring a radiation (gamma-ray) response depth according to a fourth embodiment of the related art, and the response depth is measured using a wavelength-changing fiber.

However, these conventional methods have problems in complicated circuit design and cost increase for signal acquisition, and there are limitations in that there is a problem in the accuracy of distinguishing the response depth layer.

Republic of Korea Patent Publication No. 10-1088057 (2011.11.30. Announcement) Republic of Korea Patent Publication No. 10-1025513 (2011.04.04. Announcement) Republic of Korea Patent Publication No. 10-1111011 (2012.02.15. Announcement) Republic of Korea Patent Publication No. 10-2018-0122803 (published on November 14, 2018)

Therefore, the present invention for solving the above conventional problems can improve spatial resolution by measuring the position where the scintillator and the radiation interact in various radiation detection devices including positron emission tomography devices, and thus improved An object of the present invention is to provide a radiation (gamma ray) response depth measurement method and a radiation (gamma ray) response depth measurement device for a radiation detection device based on energy separation that can improve the resolution of a system or facility having spatial resolution.

The problems to be solved of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to one aspect of the present invention for achieving the above objects and other features of the present invention, there is provided a method for measuring a reaction depth of radiation in a radiation detector including a scintillator and an optical sensor, a plurality of scintillators included in the radiation detector. It is characterized in that the signal generated through the module is generated to have different magnitudes, so that these generated signals are acquired from the photosensor, and the reaction depth of the radiation is measured by dividing the reaction layer in which the radiation and the scintillator have reacted according to the acquired signal. A radiation response depth measurement method for a radiation detection device is provided.

In addition, the present invention is a method for measuring the reaction depth of radiation in a radiation detector including a scintillator and an optical sensor (SiPM), so that the magnitudes of signals generated from a plurality of scintillators included in the radiation detector are generated differently, a generating signal acquisition step of acquiring signals of different sizes to be acquired from the optical sensor of the radiation detector; and a reaction depth measurement step of extracting and measuring a layer in which the radiation and the scintillator have reacted based on the acquired signal.

In these methods, the signal generating step comprises generating different reflected signals from reflectors provided in each scintillator constituting the scintillator module, and the step of measuring the reaction depth is the position of the photoelectric peak from the different reflected signals. It can be made to extract the position where the radiation and the scintillator reacted by separating them.

Meanwhile, the present invention provides an apparatus for measuring a reaction depth of radiation in a radiation detector, comprising: a scintillator module configured to generate signals generated with respect to radiation differently; an optical sensor module for acquiring the generated signal generated by the scintillator module; and a reaction depth measurement module for measuring a reaction depth of radiation by extracting a position where the radiation and the scintillator reacted based on the generated signal obtained from the optical sensor module; is provided

In the device of the present invention, the scintillator module is characterized in that it comprises a plurality of scintillator layers having reflectors with different reflections of the radiation.

In addition, the scintillator module may include a plurality of scintillator layers stacked, and a reflector provided on each of the scintillator layers and configured to have different reflectivities.

In addition, the scintillator module includes a scintillator layer comprising two layers; a mirror reflector wrapped around one of the scintillator layers; and a diffuse reflector wrapped around the other of the scintillator layers.

In addition, the reaction depth measurement module is characterized in that it is configured to extract the position of the photoelectric peak on the energy spectrum obtained from each scintillator layer.

According to the radiation (gamma-ray) response depth measurement method and the gamma-ray response depth measurement apparatus for a radiation detection device based on energy separation according to the present invention, the following effects are provided.

First, the present invention has the effect of improving spatial resolution because it is possible to accurately and reliably measure the position where the scintillator and the radiation interact.

Second, the present invention can improve the resolution of the entire system by improving the spatial resolution, and thus has the effect of promoting the improvement of the system performance.

Third, the present invention does not require a relatively complicated circuit design for signal acquisition, and thus has the effect of reducing costs.

Fourth, the present invention has the effect of accurately distinguishing the layers of the gamma-ray reaction depth.

Effects of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a diagram schematically showing the configuration of a radiation (gamma ray) measuring module according to a first embodiment of the related art.
FIG. 2 is a graph showing the difference in decay time in each scintillator layer by the detector according to FIG. 1 ;
3 is a diagram schematically showing the configuration of a measurement module for measuring a radiation (gamma-ray) response depth according to a second embodiment of the related art.
4 is a diagram schematically showing the configuration of a measurement module for measuring a radiation (gamma ray) response depth according to a third embodiment of the related art.
5 is a diagram schematically illustrating a configuration of a measurement module for measuring a radiation (gamma-ray) response depth according to a fourth exemplary embodiment.
6 is a flowchart illustrating a method for measuring a radiation (gamma ray) response depth for a radiation detection device based on energy separation according to the present invention.
7 is a diagram schematically illustrating an embodiment of a radiation (gamma-ray) response depth measurement device for a radiation detection device based on energy separation according to the present invention.
8 is a graph illustrating a signal generated by a scintillator module constituting a radiation (gamma ray) response depth measurement apparatus for a radiation detection device based on energy separation according to the present invention.

Additional objects, features and advantages of the present invention may be more clearly understood from the following detailed description and accompanying drawings.

Prior to the detailed description of the present invention, the present invention can make various changes and can have various embodiments, and the examples described below and shown in the drawings are not intended to limit the present invention to specific embodiments. No, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

In addition, terms such as "...unit", "...unit", "...module", etc. described in the specification mean a unit that processes at least one function or operation, which includes hardware or software or hardware and It can be implemented by a combination of software.

In addition, in the description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, throughout this specification, when a step is located “on” or “before” another step, this means not only a case in which a step is in a direct time-series relationship with another step, but also a step of mixing after each step and Likewise, the order of two stages includes the same rights as in the case of an indirect time series relationship in which the time series order can be changed.

Hereinafter, a gamma-ray response depth measurement method and a gamma-ray response depth measurement apparatus for a radiation detection device based on energy separation according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a method for measuring a radiation (gamma ray) response depth for a radiation detection device based on energy separation according to the present invention will be described in detail with reference to FIG. 6 .

6 is a flowchart illustrating a method for measuring a radiation (gamma ray) response depth for a radiation detection device based on energy separation according to the present invention.

A radiation (gamma-ray) reaction depth measurement method for a radiation detection device based on energy separation according to the present invention is a method for measuring the reaction depth of radiation (gamma-ray) in a radiation detector including a scintillator and an optical sensor, which is included in the radiation detector These generated signals are acquired from the photosensor by making the signals generated through a plurality of scintillator modules have different sizes, and the reaction depth of the radiation (audit line) is determined by dividing the reaction layer that the radiation and the scintillator reacted according to the acquired signal. It is characterized in that it is made to measure.

Specifically, the method for measuring the reaction depth of radiation (gamma rays) for a radiation detection device based on energy separation according to the present invention is a method for measuring the reaction depth of radiation (gamma rays) in a radiation detector including a scintillator and an optical sensor (SiPM). , as shown in FIG. 6 , generating signals of different magnitudes from the plurality of scintillators included in the radiation detector, and acquiring signals of different magnitudes from the optical sensor of the radiation detector (S100) ); and a reaction depth measurement step (S200) of extracting and measuring the layer in which the radiation and the scintillator reacted based on the signal obtained in the generating signal acquisition step (S100).

In the signal generating step (S100), the size of the signal obtained from the optical sensor may be different by varying the reflectance of radiation from each scintillator constituting the scintillator module.

In the step of measuring the reaction depth ( S200 ), the position of the photoelectric peak is obtained on the energy spectrum obtained from each scintillator, and the position of the obtained photoelectric peak is separated to measure the reaction depth.

More specifically, in the signal generating step (S100), the reflector surrounding each scintillator of the scintillator module uses several types having different reflectances to vary the size of the signal obtained from the optical sensor so that the optical sensor generates different signals. In the step of measuring the reaction depth ( S200 ), the reaction depth is measured by isolating the position of the photoelectric peak corresponding to the scintillator layer on the energy spectrum obtained from each scintillator. In this case, a method of measuring the reaction depth by separating the positions of the photoelectric peaks can be fully understood by those skilled in the art through various known algorithms, and thus a detailed description thereof will be omitted.

Next, a reaction depth measurement apparatus for implementing the radiation (gamma ray) reaction depth measurement method for a radiation detection device based on energy separation as described above will be described with reference to FIGS. 7 and 8 .

7 is a diagram schematically showing an embodiment of a radiation (gamma ray) response depth measurement apparatus for a radiation detection device based on energy separation according to the present invention, and FIG. 8 is a radiation detection device based on energy separation according to the present invention (gamma rays) It is a graph showing the generated signal generated by the scintillation module constituting the reaction depth measuring device.

The radiation (gamma-ray) response depth measuring apparatus for a radiation detection device based on energy separation according to the present invention is an apparatus for measuring the reaction depth of radiation (gamma-ray) in a radiation detector, and as shown in FIGS. 7 and 8, a scintillator module 100 configured to generate differently generated signals; an optical sensor module 200 provided on one side of the scintillator module 100 to obtain a generated signal generated from the scintillator module 100; and a reaction depth measurement module 300 for measuring a reaction depth of radiation by extracting a layer that reacts with radiation and a scintillator based on the generated signal obtained from the photosensor module 200 .

The scintillator module 100 is provided with reflectors having different reflectances for radiation in the scintillator layer 110 constituting the scintillator module 100 . In this case, the reflector is provided to surround each scintillator layer, for example. Accordingly, each scintillator layer reflects radiation having a different reflectivity. Reference numeral 101 denotes optical grease.

More specifically, the scintillator module 100 includes a plurality of scintillator layers 110 that are stacked, and a reflector (not shown) that surrounds each of the scintillator layers 110 and is configured to have different reflectivities. do.

For example, as shown in the drawings, the scintillator module 100 is composed of two scintillator layers, and a reflector surrounding it may be composed of a specular reflector and a diffuse reflector, respectively. In this configuration, the photosensor module 200 acquires signals of different sizes from each scintillator layer 110 .

And the reaction depth measurement module 300 is configured to measure the reaction depth by separating the position of the photoelectric peak corresponding to the scintillator layer in the energy spectrum.

In other words, the reaction depth measurement module 300 can extract and confirm the position of the photoelectric peak on the energy spectrum obtained from each scintillator layer.

That is, FIG. 8 shows the position of the photoelectric peak on the energy spectrum obtained from the scintillator layer on one side (the scintillator layer of the upper layer in FIG. 7) and the scintillator layer on the other side (the scintillator layer of the lower layer in FIG. 7) through simulation. The signal generated in the lower scintillator layer is larger than that of the scintillator layer, and the upper and lower layers can be clearly distinguished, and accordingly, the layer in which the radiation and the scintillator reacted can be identified.

According to the gamma-ray response depth measurement method and the gamma-ray response depth measurement apparatus for a radiation detection device based on energy separation according to the present invention as described above, it is possible to accurately and reliably measure the location where the scintillator and the radiation interact, thereby improving spatial resolution. can be improved, and the overall resolution of the system employing the same can be improved by improving the spatial resolution, and accordingly, there is an advantage in that the system performance can be improved.

In addition, the present invention does not require a relatively complicated circuit design for signal acquisition, thereby reducing costs, and has the advantage of accurately distinguishing layers of gamma-ray response depth.

In addition, the present invention can be simply applied by configuring various types of reflectors to the scintillator used in the existing detector. That is, the scintillator is wrapped with a reflector in order to transmit the maximum light to the optical sensor. Since it is a method using only these types of reflectors, it is possible to minimize additional costs and improve performance, thereby promoting excellent performance. There is this.

The gamma-ray response depth measurement method and gamma-ray response depth measurement apparatus for a radiation detection device based on energy separation according to the present invention as described above are in all fields of detecting and imaging radiation, for example, a nuclear power plant monitoring system, a place where people gather. It can be applied to the monitoring system of medical devices and the detection system of medical devices using radiation.

Although the embodiments as described above have been described with reference to the limited drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

The embodiments described in this specification and the accompanying drawings are merely illustrative of some of the technical ideas included in the present invention. Therefore, since the embodiments disclosed in the present specification are for explanation rather than limitation of the technical spirit of the present invention, it is obvious that the scope of the technical spirit of the present invention is not limited by these embodiments. Modifications and specific embodiments that can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be interpreted as being included in the scope of the present invention.

S100: generating signal acquisition step
S200: reaction depth measurement step
100: scintillator module
110: scintillator layer
200: optical sensor module
300: response depth measurement module

Claims (8)

A method for measuring the response depth of radiation in a radiation detector comprising a scintillator and an optical sensor, the method comprising:
The signals generated through the plurality of scintillator modules included in the radiation detector are generated to have different magnitudes, and these generated signals are acquired from the photosensor. characterized in that it is made to measure
Radiation response depth measurement method for radiation detection equipment.
A method for measuring the response depth of radiation in a radiation detector comprising a scintillator and a photosensor (SiPM), the method comprising:
a generating signal acquiring step of generating signals of different magnitudes from the plurality of scintillators included in the radiation detector and acquiring signals of different magnitudes from the optical sensor of the radiation detector; and
A reaction depth measurement step of extracting and measuring the layer in which the radiation and the scintillator reacted based on the obtained signal;
Radiation response depth measurement method for radiation detection equipment.
3. The method of claim 1 or 2,
The signal generating step consists in generating different reflected signals from reflectors provided in each scintillator constituting the scintillator module,
The reaction depth measurement step is characterized in that the position of the photoelectric peak is separated from the other reflected signals to extract the position where the radiation and the scintillator reacted.
Radiation response depth measurement method for radiation detection equipment.
A device for measuring the reaction depth of radiation in a radiation detector, comprising:
a scintillator module configured to generate signals generated for radiation differently;
an optical sensor module for acquiring the generated signal generated by the scintillator module; and
and a reaction depth measurement module for measuring the reaction depth of radiation by extracting a position where the radiation and the scintillator react based on the generated signal obtained from the optical sensor module.
Radiation response depth measuring device for radiation detection equipment.
5. The method of claim 4,
wherein the scintillator module comprises a plurality of scintillator layers having reflectors that each have different reflections for radiation.
Radiation response depth measuring device for radiation detection equipment.
5. The method of claim 4,
The scintillator module,
a plurality of scintillator layers provided in a stack, and
Including; a reflector provided on each of the scintillator layers and configured to have different reflectivities
Radiation response depth measuring device for radiation detection equipment.
5. The method of claim 4,
The scintillator module,
a scintillator layer consisting of two layers;
a mirror reflector wrapped around one of the scintillator layers; and
and a diffuse reflector provided to surround the other one of the scintillator layers.
Radiation response depth measuring device for radiation detection equipment.
8. The method according to any one of claims 4 to 7,
The reaction depth measurement module is configured to extract the position of the photoelectric peak on the energy spectrum obtained from each scintillator layer.
Radiation response depth measuring device for radiation detection equipment.

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