KR102679432B1 - Scintillator detector and positron emission tomography apparatus using the same - Google Patents

Abstract

A scintillation detector and a positron emission tomography device using the same are provided. The scintillation detector includes a scintillation crystal unit including at least one prismatic scintillation crystal that detects radiation and converts it into a scintillation signal; a photoelectric device including at least one optical sensor disposed on the scintillation crystal; and a light reflection unit including at least one reflector that reflects the flash signal at both ends of the scintillation crystal, wherein the optical sensor rotates 45° in one direction and detects at least one of the upper or lower surfaces of the scintillation crystal. They can be placed uniformly and spaced at predetermined intervals on one surface.

Description

Scintillation detector and positron emission tomography device using the same {SCINTILLATOR DETECTOR AND POSITRON EMISSION TOMOGRAPHY APPARATUS USING THE SAME}

The present invention relates to a scintillation detector and a positron emission tomography device using the same. More specifically, the present invention relates to a scintillation detector and a positron emission tomography device using the same. More specifically, an optical sensor rotated 45° in one direction on the top surface (TOP) and/or bottom surface (BOTTOM) of a scintillation crystal is used to detect the scintillation crystal and light. By evenly arranging the sensors so that they contact each other, the number of optical sensors is minimized rather than the number of scintillation crystals, and a scintillation signal with depth of interaction (DOI) information between scintillation crystals is detected, maintaining sensitivity while maintaining improved spatial resolution. It relates to a scintillation detector and a positron emission tomography device using the same.

Generally, positron emission tomography (PET) is a tomography device that uses radiation, such as X-ray computed tomography (CT) and single photon emission computerized tomography (SPECT). am.

Positron emission tomography is a technology that images the distribution of foreign substances in the body by injecting radioactive samples that emit positrons into the living body by intravenous injection or inhalation and then detecting them for research and diagnosis. For example, based on the fact that some cancer cells accumulate more glucose than others, FDG, which combines the radioactive isotope F-18, which has a half-life of about 110 minutes, with glucose, is used to track cancer cells.

In this way, positron emission tomography devices are used for the diagnosis and research of various diseases, such as research on human metabolism, cancer diagnosis, and abnormalities in the heart and nervous system. Positron-emitting nuclides are mainly unstable isotopes with a relatively large number of neutrons in the nucleus, and nuclides such as O15, N13, C11, and F18 are mainly used in positron emission tomography devices.

By a phenomenon called “pair annihilation,” positrons emitted from positron-emitting nuclides in the human body combine with nearby electrons to emit γ-rays.

According to the law of energy conservation and momentum conservation related to the mass-energy equivalence principle, positrons that have reached a stationary state combine with nearby electrons and are converted into evanescent gamma rays with an energy of 511 keV, which are emitted in opposite directions. By detecting and analyzing a pair of γ-rays emitted in opposite directions, the location of γ-rays can be determined. As a result, the occurrence frequency of γ-rays, that is, the accumulated concentration of the labeled sample, can be obtained as a function of spatial position coordinates. You can. If the results are displayed using a display means, etc., the distribution of radionuclides in the subject's body can be known.

The most important factors that determine the performance of a positron emission tomography device are spatial resolution and sensitivity (detection efficiency). In order to achieve improved performance, it is possible to densely arrange smaller detectors, but this has certain limitations due to miniaturization of components, and further increases the cost due to an increase in the number of detectors and electronic measuring devices. .

One way to increase spatial resolution is to use depth of interaction (DOI) information. Here, interaction depth refers to the depth from the crystal to where the flash reaction occurs. Without interaction depth information, PET devices show large errors in determining the location of gamma rays due to parallax error outside the viewing area, which inevitably reduces spatial resolution. Therefore, interaction depth information within the decision is used to maintain constant spatial resolution and sensitivity without compromising spatial resolution.

The matters described as background technology above are only for the purpose of improving understanding of the background of the present invention, and should not be taken as an acknowledgment that they correspond to prior art already known to those skilled in the art.

Republic of Korea Patent No. 10-1025513 Republic of Korea Patent Publication No. 10-2011-0062622

The problem to be solved by the present invention is to provide a scintillation detector and a positron emission tomography device using the same.

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

A scintillation detector according to an embodiment of the present invention for solving the above-described problem includes a scintillation crystal unit including at least one prismatic scintillation crystal that detects radiation and converts it into a scintillation signal; a photoelectric device including at least one optical sensor disposed on the scintillation crystal; and a light reflection unit including at least one reflector that reflects the flash signal at both ends of the scintillation crystal, wherein the optical sensor rotates 45° in one direction and detects at least one of the upper or lower surfaces of the scintillation crystal. They can be placed uniformly and spaced at predetermined intervals on one surface.

In one embodiment of the present invention, each inclined surface of the optical sensor may directly contact one surface of each of the four scintillation crystals.

In one embodiment of the present invention, the optical sensor includes a first optical sensor having first to fourth vertices, and first to second optical sensors spaced apart from the first optical sensor by first and second horizontal distances in the transverse direction. It includes a second optical sensor having a fourth vertex, a third optical sensor having first to fourth vertices spaced apart from the first optical sensor by first and second vertical distances in the longitudinal direction, and the first horizontal The distance represents the distance between the first vertex of the first optical sensor and the first vertex of the second optical sensor, and the second horizontal distance is the second vertex of the first optical sensor and the fourth vertex of the second optical sensor. represents the distance between, and the first vertical distance represents the distance between the fourth vertex of the first optical sensor and the fourth vertex of the third optical sensor, and the second vertical distance represents the third vertex of the first optical sensor It may represent the distance between and the first vertex of the third optical sensor.

In one embodiment of the present invention, when the arrangement of the scintillation crystal is n*m, the square-shaped optical sensor rotates 45° around the vertex of the pixel of the scintillation crystal to detect the upper or lower surface of the scintillation crystal. (n/2) + (m/2) numbers are disposed at predetermined intervals in the horizontal and vertical directions, and the reflector is at least one of the upper or lower surface of the scintillation crystal on which the optical sensor is not disposed. It can be placed on the side.

In one embodiment of the present invention, when the arrangement of the scintillation crystal is n*m, the square-shaped optical sensor rotates 45° around the vertex of the pixel of the scintillation crystal to measure the upper and lower surfaces of the scintillation crystal. Above, (n/2)+(m/2) numbers may be arranged at predetermined intervals in the horizontal and vertical directions.

In one embodiment of the present invention, the reflector may be disposed to correspond to a spaced portion between the scintillation crystal and the optical sensor that does not contact the optical sensor.

In one embodiment of the present invention, when the optical sensor and the reflector are repeatedly disposed on the upper and lower surfaces of the scintillation crystal, the optical sensor and the reflector on the upper and lower surfaces of the scintillation crystal Arrangements may be arranged identically or differently from each other.

In one embodiment of the present invention, it may further include a light guide portion disposed between the scintillation crystal and an upper surface of the scintillation crystal or between the scintillation crystal and a lower surface of the scintillation crystal.

In one embodiment of the present invention, the optical sensor may be arranged in a ratio of 1/2 of the total area of the upper or lower surface of the scintillation crystal.

In one embodiment of the present invention, the reflector may be formed on at least one of the side surfaces of the scintillation crystal.

In addition, a positron emission tomography apparatus according to an embodiment of the present invention for solving the above-described problem includes a detector ring formed by the at least one scintillation detector and a signal that analyzes and processes the optical signal detected by the scintillation detector. Detection means including processing means; and an image output means for converting the data obtained through the signal processing means into an image signal and displaying it.

Other specific details of the invention are included in the detailed description and drawings.

According to the present invention, spatial resolution is achieved while minimizing the number of optical sensors rather than the number of scintillation crystals by using a scintillation detector in which optical sensors rotated 45° in one direction are placed on the top surface (TOP) and the bottom surface (BOTTOM) of the scintillation crystal. By increasing the effect and obtaining depth of interaction (DOI) information between scintillation crystals, it is possible to provide a positron emission tomography (PET) device with high sensitivity and high resolution that minimizes image distortion that occurs outside of the PET field of view.

According to the present invention, an optical sensor rotated 45° in one direction is disposed only on the upper or lower surface of the scintillation crystal, and a scintillation detector in which a reflector is disposed in the area where the optical sensor is not placed is used to detect more light than the number of scintillation crystals. A high-sensitivity, high-resolution positron emission tomography device that minimizes image distortion occurring outside the PET field of view by acquiring depth of interaction (DOI) information between scintillation crystals by minimizing the number of sensors and increasing the spatial resolution effect. PET) can be provided.

According to the present invention, instead of individually matching the scintillation crystal and the photosensor in the total area of the scintillation crystal, the photosensor is arranged in a proportion of 1/2 of the total area of the scintillation crystal, so that the scintillation is generated as a whole regardless of the size of the scintillation crystal. The detector can maintain uniform performance and reduce costs at the same time.

According to the present invention, the scintillation detector to which the present invention is applied and the positron emission tomography device using the same can be widely applied in the fields of experimental animal imaging, gene expression or treatment, cancer diagnosis and treatment research, and new drug development. Nuclear physics, It can contribute to the development of advanced medical devices that require complex technologies in nuclear medicine, nuclear engineering, materials engineering, electrical and electronic engineering, control engineering, computer engineering, and new materials engineering, as well as to the development of the domestic medical industry and various academic fields.

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

1 is a diagram for explaining a scintillation detector according to an embodiment of the present invention.
Figure 2 is a diagram for explaining the arrangement of photoelectric elements disposed in a scintillation crystal according to an embodiment of the present invention.
Figure 3 is a diagram for explaining the arrangement of photoelectric elements disposed on the contact surface of the scintillation crystal.
Figure 4 is a diagram for explaining the arrangement of photoelectric elements disposed in a scintillation crystal according to another embodiment of the present invention.
Figure 5 is a diagram for explaining the arrangement of photoelectric elements disposed in a scintillation crystal according to another embodiment of the present invention.
Figure 6 is a diagram for explaining the arrangement of photoelectric elements and reflectors disposed in a scintillation crystal according to another embodiment of the present invention.
Figure 7 is a diagram for explaining a scintillation detector according to another embodiment of the present invention.
Figure 8 is a diagram for explaining a positron emission tomography apparatus using a scintillation detector according to an embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to provide a general understanding of the technical field to which the present invention pertains. It is provided to fully inform the skilled person of the scope of the present invention, and the present invention is only defined by the scope of the claims.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other elements in addition to the mentioned elements. Like reference numerals refer to like elements throughout the specification, and “and/or” includes each and every combination of one or more of the referenced elements. Although “first”, “second”, etc. are used to describe various components, these components are of course not limited by these terms. These terms are merely used to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may also be a second component within the technical spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless clearly specifically defined.

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

Figure 1 is a diagram for explaining a scintillation detector according to an embodiment of the present invention, Figure 2 is a diagram for explaining the arrangement of photoelectric elements disposed in a scintillation crystal according to an embodiment of the present invention, and Figure 3 is a diagram for explaining the arrangement of the photoelectric elements disposed on the contact surface of the scintillation crystal, and Figures 4 to 6 are diagrams for explaining the arrangement of the photoelectric elements disposed on the scintillation crystal according to another embodiment of the present invention. . Figures 4(a) and 4(b) are diagrams for explaining the arrangement of photoelectric elements arranged in different arrangements on the upper and lower surfaces of the scintillation crystal, and Figures 5(a) and 5(b) is a diagram to explain the arrangement of the photoelectric elements arranged in the same arrangement on the upper and lower surfaces of the scintillation crystal, and Figure 6(a) illustrates the arrangement of the photoelectric elements arranged on the upper surface of the scintillation crystal. 6(b) is a diagram for explaining the arrangement of reflectors disposed on the lower surface of the scintillation crystal.

As shown in FIG. 1, the scintillation detector 1 according to an embodiment of the present invention includes a scintillation crystal portion 10 made of a scintillation crystal 12, an upper surface 120 and a lower portion of the scintillation crystal 12. A photoelectric element 20 consisting of an optical sensor 22 disposed on the surface 122 and partially contacting the scintillation crystal 12, and disposed on the upper surface 120 and the lower surface 122 of the scintillation crystal 12. It may include a light reflection unit 30 made of a reflector 32 that is partially in contact with the scintillation crystal 12.

The scintillation crystal unit 10 may include a plurality of scintillation crystals 12 each having the size of a square pixel. At this time, the scintillation crystal 12 may be manufactured in the form of a rectangular parallelepiped with a square cross-section using a scintillation material. This makes it possible to detect a response only to a certain pulse of gamma rays, and in particular, the flash can be directed to the photoelectric element 20 through the center of the scintillation crystal 12, which has a rectangular parallelepiped shape. Alternatively, the flash crystal 12 may have the shape of a polygonal pillar.

The scintillation crystals 12 may be arranged in a rectangular matrix including n horizontally and m vertically. Here, n and m are preferably integers of 1 or more.

In this embodiment, the plurality of flash crystals 12 is composed of 36 pieces with a 6*6 (n*m) arrangement, and the pixel size is Although disclosed as being, it is not limited to this.

The photoelectric element 20 may include an optical sensor 22 that is uniformly disposed at regular intervals on the upper surface 120 and/or the lower surface 122 of the scintillation crystal 12. At this time, the optical sensor 22 can convert the incident flash signal on a pixel basis into an electrical signal.

Specifically, when the scintillation signal generated in the above-described scintillation crystal unit 10 is reflected by the light reflection unit 30 and becomes incident, the optical sensor 22 may convert the incident scintillation signal into an electrical signal. At this time, the electrical signal may include information related to the location of the pixel, the location where the flash was incident on the pixel, and the intensity of the flash signal converted to an electrical signal.

One of the four sides of the optical sensor 22 can be in direct contact with each side of the four scintillation crystals 12.

Depending on the embodiment, when the scintillation detector 1 has a single-ended readout structure, the optical sensor 22 may be disposed at a predetermined interval on the lower surface 122 of the scintillation crystal 12. there is. At this time, the reflector 32 is disposed corresponding to the spaced portion between the optical sensor 22 that is not in contact with the scintillation crystal 12 on the lower surface 122, and can be disposed on the entire surface of the upper surface 120. there is.

Alternatively, the optical sensor 22 may be disposed on the upper surface 120 of the scintillation crystal 12 at predetermined intervals.

Depending on the embodiment, when the scintillation detector 1 has a dual-ended readout structure, it may be disposed on the upper and lower surfaces 122 of the scintillation crystal 12 at a predetermined interval. At this time, the reflector 32 may be disposed on the upper surface 120 and the lower surface 122 to correspond to a spaced portion between the optical sensors 22 that do not contact the scintillation crystal 12.

Meanwhile, the optical sensor 22 may be disposed at a ratio of 1/2 compared to the total area of the scintillation crystal portion 10, but is not limited to this.

The light reflection unit 30 may reflect the scintillation signal generated by the scintillation crystal unit 10 by converting radiation toward the scintillation crystal unit 10 . The light reflection unit 30 is a reflector ( 32) may be included.

The four sides of the reflector 32 can simultaneously contact one side of the four scintillation crystals 12 and one side of the four optical sensors 22, respectively.

For example, the reflector 32 may be disposed between the optical sensor 22 spaced apart from the upper surface 120 and the lower surface 122 of the scintillation crystal 12. That is, the reflector 32 may be disposed corresponding to a spaced portion between the scintillation crystal 12 and the optical sensor 22 that is not in contact.

In other words, when the scintillation detector 1 has a dual-ended readout structure, both longitudinal ends of the scintillation crystal 12 can directly contact the photoelectric element 20 and the light reflection unit 30. there is.

For example, as shown in FIG. 2(a), when the pixels of the scintillation crystal 12 are configured in a 6*6 array, 18 optical sensors 22 are installed on the upper surface 120 of the scintillation crystal 12. The pixels of the scintillation crystal 12 are rotated by 45° around the apex (a) and are uniformly spaced apart at regular intervals, and a reflector 32 may be placed between the spaced apart optical sensors 22.

More specifically, when the arrangement of the scintillation crystals 12 is n*m, (n/2)+(m/2) optical sensors 22 are spaced at a predetermined distance from the upper surface 120 of the scintillation crystals 12. It can be placed spaced apart. The reflector 32 may be disposed on the remaining portion of the upper surface 120 of the scintillation crystal 12 where the optical sensor 22 is not placed, that is, a portion where the scintillation crystal 12 and the optical sensor 22 do not contact. there is.

In other words, when the plurality of scintillation crystals 12 consists of 36 pieces arranged in a 6*6 (n*m) arrangement, the optical sensor 22 has 9 3*3 scintillation crystals 12 on the upper surface 120 of the scintillation crystal 12. It is arranged in an array, and the 18 optical sensors 22 can directly contact the upper surface 120 of the scintillation crystal 12, and the reflector 32 is used to flash the remaining portion where the optical sensor 22 is not arranged. It may be in direct contact with the upper surface 120 of the crystal 12.

At this time, the nine optical sensors 22 arranged on the upper surface 120 of the scintillation crystal 12 by rotating 45° around the vertex (a) of the pixel of the scintillation crystal 12 are positioned at a predetermined angle in the horizontal and vertical directions. They can be spaced apart and placed evenly.

Specifically, a first optical sensor 221 having first to fourth vertices (p11, p12, p13, p14) and a second optical sensor having first to fourth vertices (p21, p22, p23, p24) ( 222) and the third optical sensor 223 having the first to fourth vertices (p31, p32, p33, p34) are spaced apart by the first and second horizontal distances (c1, c2) in the horizontal direction, and are spaced apart in the longitudinal direction by the first and second horizontal distances (c1, c2). They may be arranged to be spaced apart by the first and second vertical distances (r1, r2). At this time, the second optical sensor 222 may be arranged in the horizontal direction around the first optical sensor 221, and the third optical sensor 223 may be arranged in the longitudinal direction, but the arrangement is not limited thereto.

For example, as shown in FIG. 3, the first vertex (p11) of the first optical sensor 221 and the first vertex (p21) of the second optical sensor 222 are the first horizontal distance (c1). They are spaced laterally at 4.6mm intervals, and the second vertex (p12) of the first optical sensor 221 and the fourth vertex (p24) of the second optical sensor 222 are 0.357mm, which is the second horizontal distance (c2). They can be spaced laterally at intervals.

In addition, the fourth vertex (p14) of the first optical sensor 221 and the fourth vertex (p34) of the third optical sensor 223 are spaced apart in the longitudinal direction at an interval of 4.6 mm, which is the first vertical distance r1, The third vertex p13 of the first optical sensor 221 and the first vertex p31 of the third optical sensor 223 may be spaced apart in the longitudinal direction at an interval of 0.357 mm, which is the second vertical distance r2.

Meanwhile, each surface (22a, 22b, 22c, 22d) of the optical sensor 22 is the first to fourth surfaces (121a, 121b, 121c) of the first to fourth scintillation crystals (12a, 12b, 12c, 12d). , 121d) can be directly contacted, respectively.

In other words, the first surface 22a of the optical sensor 22 is in direct contact with the first surface 121a of the first scintillation crystal 12a, and the second surface 22b of the optical sensor 22 is in direct contact with the first surface 121a of the first scintillation crystal 12a. 2 It is in direct contact with the second surface (121b) of the flash crystal (12b), and the third surface (22c) of the optical sensor 22 is in direct contact with the third surface (121c) of the third flash crystal (12c). And, the fourth surface (22d) of the optical sensor 22 may directly contact the fourth surface (121d) of the fourth scintillation crystal (12d).

Accordingly, the optical sensors 22 are evenly spaced apart from the scintillation crystal 12 in a 45° rotated state and are arranged at predetermined intervals, so that the four sides of the optical sensor 22 are aligned with the four scintillation crystals 12. Each side can be contacted directly.

According to the embodiment, the optical sensor 22 is arranged at a ratio of 1/2 of the total area of the scintillation crystal 12, thereby reducing the number of optical sensors 22 to 1/2 that of the scintillation crystal 12 and allowing the optical sensor (22) and flash crystal (12) are in direct contact The spatial resolution effect can be increased through the size of the scintillation crystal (12).

Moreover, by arranging the reflector 32 on a portion of the upper surface 120 of the scintillation crystal 12 that is not in contact with the scintillation crystal 12 and the optical sensor 22, the scintillation signal is transmitted to the lower surface of the scintillation crystal 12. (122) By reflecting more efficiently, the spatial resolution effect can be increased and depth of interaction (DOI) information between scintillation crystals can be obtained.

In addition, as shown in FIG. 2(b), when the pixels of the scintillation crystal 12 are configured in a 6*6 array, 16 optical sensors 22 are provided on the lower surface 122 of the scintillation crystal 12. The crystal 12 is rotated 45° around the vertex a of the pixel and is uniformly spaced at regular intervals, and a reflector 32 may be placed between the spaced optical sensors 22.

More specifically, when the arrangement of the flash crystals 12 is n*m, the optical sensor 22 has ((n/2)+1)*((m/2)+1) of the flash crystals 12. They may be arranged to be spaced apart at predetermined intervals on the lower surface 122. The reflector 32 may be disposed on the remaining portion of the lower surface 122 of the scintillation crystal 12 where the optical sensor 22 is not disposed.

In other words, when the plurality of scintillation crystals 12 consists of 36 pieces arranged in a 6*6 (n*m) arrangement, the optical sensor 22 has 16 scintillation crystals 12 on the lower surface 122 of 4*4. Arranged in an array, it can be in direct contact with the lower surface 122 of the scintillation crystal 12, and the reflector 32 is the remaining part where the optical sensor 22 is not arranged, that is, the scintillation crystal 12 and the optical sensor. (22) may be placed in a non-contact area.

At this time, the 16 optical sensors 22 arranged on the lower surface 122 of the scintillation crystal 12 by rotating 45° around the vertex (a) of the pixel of the scintillation crystal 12 are positioned at a predetermined angle in the horizontal and vertical directions. It can be placed spaced apart at intervals.

Meanwhile, each surface (23a, 23b, 23c, 23d) of the optical sensor 22 is the first to fourth surfaces (131a, 131b, 131c) of the first to fourth scintillation crystals (13a, 13b, 13c, 13d). , 131d) can be directly contacted, respectively.

In other words, the first surface 23a of the optical sensor 22 is in direct contact with the first surface 131a of the first scintillation crystal 13a, and the second surface 23b of the optical sensor 22 is in direct contact with the first surface 131a of the first scintillation crystal 13a. 2 It is in direct contact with the second surface (131b) of the flash crystal (13b), and the third surface (23c) of the optical sensor 22 is in direct contact with the third surface (131c) of the third flash crystal (13c). And, the fourth surface (23d) of the optical sensor 22 may directly contact the fourth surface (131d) of the fourth scintillation crystal (13d).

Moreover, by arranging the reflector 32 on a portion of the lower surface 122 of the scintillation crystal 12 that is not in contact with the scintillation crystal 12 and the optical sensor 22, the scintillation signal is transmitted to the upper surface of the scintillation crystal 12. (120) By reflecting more efficiently, the spatial resolution effect can be increased and depth of interaction (DOI) information between scintillation crystals can be obtained.

Depending on the embodiment, the reflector 32 may be disposed on at least one side of the scintillation crystal 12.

In the bidirectionally readable scintillation detector (1) of this structure, when the plurality of scintillation crystals (12) consists of 36 pieces in a 6*6 (n*m) arrangement, a total of 25 optical sensors (22) By arranging the flash crystals 12 in a 3*4 array on the upper surface 120 and a 4*4 array on the lower surface 122 at predetermined intervals, the number of optical sensors 22 is greater than the number of flash crystals 12. It is possible to obtain depth of interaction (DOI) information between scintillation crystals by minimizing the number and increasing the spatial resolution effect.

Meanwhile, depending on the embodiment, as shown in FIG. 4, the optical sensors 22 may be arranged in different arrangements on the upper surface 120 and the lower surface 122 of the scintillation crystal 12. At this time, the half-body 32 may be disposed corresponding to a spaced portion between the scintillation crystal 12 and the optical sensor 22 that is not in contact.

For example, when the plurality of scintillation crystals 12 consists of 36 pieces arranged in a 6*6 (n*m) arrangement, a total of 25 optical sensors 22 are installed on the upper surface 120 of the scintillation crystal 12 (4). It is arranged in *3 arrangement (see FIG. 4(a)), and may be arranged in a 3*4 arrangement on the lower surface 122 at predetermined intervals (see FIG. 4(b)).

Depending on the embodiment, the reflector 32 may be disposed on at least one side of the scintillation crystal 12.

In this way, the optical sensor 22 is arranged not to face each other on the upper surface 120 and the lower surface 122 of the scintillation crystal 12, thereby increasing the amount of light reflected in both directions, thereby increasing the number of scintillation crystals 12. By minimizing the number of optical sensors 22 and increasing the spatial resolution effect, depth of interaction (DOI) information between scintillation crystals can be obtained.

Depending on the embodiment, as shown in FIG. 5, the optical sensors 22 may be arranged in the same arrangement on the upper surface 120 and the lower surface 122 of the scintillation crystal 12. At this time, the half body 32 may be disposed corresponding to a spaced portion between the scintillation crystal 12 and the optical sensor 22 that is not in contact.

For example, when the plurality of scintillation crystals 12 consists of 36 pieces arranged in a 6*6 (n*m) arrangement, a total of 25 optical sensors 22 are installed on the upper surface 120 of the scintillation crystal 12 (4). It is arranged in a *3 arrangement (see Figure 5(a)), and may be arranged in a 4*3 arrangement on the lower surface 122 at predetermined intervals (see Figure 5(b)).

Depending on the embodiment, the reflector 32 may be disposed on at least one side of the scintillation crystal 12.

In this way, the optical sensors 22 are arranged to face each other on the upper surface 120 and the lower surface 122 of the scintillation crystal 12, thereby increasing the amount of light reflected in both directions to increase the number of scintillation crystals 12. By minimizing the number of optical sensors 22 and increasing the spatial resolution effect, depth of interaction (DOI) information between scintillation crystals can be obtained.

On the other hand, when the scintillation detector 1 has a single-ended readout structure, at least one cross section of both longitudinal ends of the scintillation crystal 12 is connected to the photoelectric element 20 and the light reflection unit 30. It can be in direct contact. For example, as shown in FIG. 6(a), when the pixels of the scintillation crystal 12 are configured in a 6*6 array, the upper surface 120 of the scintillation crystal 12 A total of 36 reflectors may be arranged overall, but the reflector is not limited to this and may be arranged spaced apart at predetermined intervals. That is, the optical sensor 22 may not be disposed on the upper surface 120 of the scintillation crystal 12.

In addition, as shown in FIG. 6(b), when the pixels of the scintillation crystal 12 are configured in a 6*6 array, 18 photosensors 22 are provided on the lower surface 122 of the scintillation crystal 12. The pixels of the crystal 12 can be rotated by 45° around the vertex (a) and spaced apart at regular intervals to be uniformly arranged in a 4*3 array. At this time, a reflector 32 may be disposed between the spaced apart optical sensors 22.

Depending on the embodiment, the optical sensor 22 may be disposed on the upper surface 120 of the scintillation crystal 12, and the optical sensor 22 may not be disposed on the lower surface 122.

Depending on the embodiment, the reflector 32 may be disposed on at least one side of the scintillation crystal 12.

In this way, the optical sensor 22 is disposed at a predetermined interval only on at least one of the upper surface 120 and the lower surface 122 of the scintillation crystal 12, so that light is reflected in one direction. By increasing the amount, it is possible to obtain depth of interaction (DOI) information between scintillation crystals by increasing the spatial resolution effect while minimizing the number of optical sensors 22 rather than the number of scintillation crystals 12.

The scintillation detector 1, which can read in one direction or two directions, has an optical sensor 22 rotated by 45° at both ends of the upper surface 120 and/or the lower surface 122 of the scintillation crystal 12. By arranging them to be evenly spaced apart in a diamond shape, a difference (signal loss) in the contact surfaces of the upper surface 120 and the lower surface 122 may not occur. In other words, no contact error occurs between the optical sensors 22 disposed on the upper surface 120 and the lower surface 122, so the sensitivity is maintained by detecting a scintillation signal with depth of interaction (DOI) information between scintillation crystals. It is possible to have improved spatial resolution while maintaining it.

In addition, by disposing the reflector 32 on the portion of the upper surface 120 and/or the lower surface 122 of the scintillation crystal 12 that is not in contact with the scintillation crystal 12 and the optical sensor 22, the scintillation signal is By reflecting more efficiently to both ends of the scintillation crystal 12, the spatial resolution effect can be increased, and depth of interaction (DOI) information between scintillation crystals can be obtained.

Figure 7 is a diagram for explaining a scintillation detector according to another embodiment of the present invention.

Referring to FIG. 7, a scintillation detector 2 according to another embodiment of the present invention may include a light guard unit 14.

Except for the light guard unit 14 shown in FIG. 7, it may have the same characteristics as the scintillation detector 1 shown in FIGS. 1 to 6.

In FIG. 7 below, detailed description of content that overlaps with that shown in FIGS. 1 to 6 may be omitted and the description will focus on differences. Accordingly, components that perform the same function as the scintillation detector 2 shown in FIG. 7 are assigned the same reference numerals as those in FIGS. 1 to 6, and detailed descriptions thereof are omitted.

First, referring to FIG. 7, the scintillation detector 2 may include a light guard portion 14 having a predetermined thickness.

The light guide unit 14 may be disposed between the scintillation crystal 12 and the upper surface 120 and/or between the lower surface 122 and the scintillation crystal 12. That is, the scintillation crystal 12 and the optical sensor 22 may not directly contact each other.

Specifically, the first light guide portion 140 is disposed between the flash crystal 12 and the upper surface 120 of the flash crystal 12, and the lower surface 122 of the flash crystal 12 and the flash crystal 12. ) The second light guide unit 142 may be selectively disposed between the two.

Depending on the embodiment, a reflector 32 may be formed on the side of the scintillation crystal 12 of the scintillation detector 2, that is, at least one of the four sides.

The scintillation detector 2 of this structure includes a light guide unit 14 to prevent direct contact between the scintillation crystal 12 and the optical sensor 22, so that the scintillation crystal 12 is detected through the light guide unit 14. Light reflected in one direction or two directions can be concentrated and transmitted to the optical sensor 22. Accordingly, even if the optical sensor 22 is reduced without causing a contact error between the optical sensors 22 disposed on the upper surface 120 and the lower surface 122, depth of interaction (DOI) information between scintillation crystals is provided. By detecting scintillation signals with , improved spatial resolution can be achieved while maintaining sensitivity.

Figure 8 is a diagram for explaining a positron emission tomography apparatus using a scintillation detector according to an embodiment of the present invention.

Referring to FIG. 8, the positron emission tomography apparatus 100 includes a scintillation detector 1, a detection means 2 including a detector ring 3 formed in a ring shape, a signal processing means 4, and an image output means. (5) may be included.

The detection means (2) can detect a gamma signal by forming a detector ring (3) in which the scintillation detector (1) is radially arranged.

The signal processing means 4 may include a computer or other computing device with a built-in program that analyzes the data detected by the detection means 2 and determines the generation location of the γ-ray.

The program used in this device can perform an operation to determine the DOI of each output pulse based on the waveform of the pulse because the data output from the detection unit includes DOI information based on the type of crystal and the offset between crystal layers.

The image output means (5) can display the image signal received from the signal processing means (4).

In the positron emission tomography apparatus 100 of this structure, a subject is mounted in a cylindrical internal space.

Above, embodiments of the present invention have been described with reference to the attached drawings, but those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will be able to understand it. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

1, 2: scintillation detector 100: positron emission tomography device
10: flash crystal part 12: flash crystal
120: upper surface 122: lower surface
20: photoelectric element 22: optical sensor
30: light reflection unit 32: reflector

Claims (11)

a scintillation crystal unit including at least one prismatic scintillation crystal that detects radiation and converts it into a scintillation signal;
a photoelectric device including at least one optical sensor disposed on the scintillation crystal; and
It includes a light reflection unit including at least one reflector that reflects the flash signal at both ends of the scintillation crystal,
The optical sensor is,
It is rotated 45° in one direction and is evenly spaced at predetermined intervals on at least one of the upper or lower surfaces of the scintillation crystal,
Each slope of the optical sensor is in direct contact with one surface of each of the four scintillation crystals,
The optical sensor is,
A first optical sensor having first to fourth vertices, a second optical sensor having first to fourth vertices spaced apart from the first optical sensor by first and second horizontal distances in the transverse direction, and the first optical sensor It includes a third optical sensor having first to fourth vertices spaced apart from the optical sensor by first and second vertical distances in the longitudinal direction,
The first horizontal distance represents the distance between the first vertex of the first optical sensor and the first vertex of the second optical sensor,
The second horizontal distance represents the distance between the second vertex of the first optical sensor and the fourth vertex of the second optical sensor,
The first vertical distance represents the distance between the fourth vertex of the first optical sensor and the fourth vertex of the third optical sensor,
The second vertical distance represents the distance between the third vertex of the first optical sensor and the first vertex of the third optical sensor. delete delete According to paragraph 1,
When the arrangement of the scintillation crystal is n*m, the square-shaped optical sensor rotates 45° around the vertex of the pixel of the scintillation crystal and is positioned on the upper or lower surface of the scintillation crystal in the horizontal and vertical directions (n /2) + (m/2) number of scintillation detectors are disposed at predetermined intervals, and the reflector is disposed on at least one of the upper or lower surfaces of the scintillation crystal where the optical sensor is not disposed. According to paragraph 1,
When the arrangement of the scintillation crystal is n*m, the square-shaped optical sensor rotates 45° around the vertex of the pixel of the scintillation crystal and is positioned on the upper and lower surfaces of the scintillation crystal in the horizontal and vertical directions (n /2)+(m/2) scintillation detectors each arranged at a predetermined interval. According to clause 5,
The reflector is,
A scintillation detector disposed corresponding to a spaced portion between the scintillation crystal and the optical sensor that is not in contact with the optical sensor. According to clause 6,
When the optical sensor and the reflector are repeatedly arranged on the upper and lower surfaces of the scintillation crystal, the arrangement of the optical sensor and the reflector on the upper and lower surfaces of the scintillation crystal is the same or different from each other. Arranged, scintillation detector. According to paragraph 1,
A scintillation detector further comprising; a light guide portion disposed between the scintillation crystal and an upper surface of the scintillation crystal or between the scintillation crystal and a lower surface of the scintillation crystal. According to paragraph 1,
A scintillation detector wherein the optical sensor is disposed at a ratio of 1/2 of the total area of each of the upper or lower surfaces of the scintillation crystal. According to paragraph 1,
A scintillation detector wherein the reflector is formed on at least one side of the scintillation crystal. Detection means including a detector ring formed by at least one scintillation detector according to any one of claims 1, 4 to 10, and signal processing means for analyzing and processing the optical signal detected by the scintillation detector; and
An image output means for converting the data acquired through the signal processing means into an image signal and displaying it. A positron emission tomography apparatus comprising a.

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