KR20100122596A - Transformable adaptive positron emission tomography system and imaging method using the same - Google Patents

Abstract

PURPOSE: A changeable shape adaptive PET(Position Emission Tomography) device and a photographing method using the same are provide to supply the photographing device condition suitable for each subject, thereby enhancing the space resolution and sensitivity. CONSTITUTION: A rotary motion unit is comprised of a first rotating axis(30), a rotary wing(20) connected to the first rotating axis and a gamma-ray detector(10) which detects the gamma-ray by being included in the rotary wing. A driving unit is connected to the first rotating axis and drives the rotary motion unit. A programmable logic controller is connected to the gamma-ray detector and calculates the occurrence location of the gamma-ray. A display unit is connected to the programmable logic controller and displays an image of the subject.

Description

Variable shape adaptive positron emission tomography device and imaging method using the same {TRANSFORMABLE ADAPTIVE POSITRON EMISSION TOMOGRAPHY SYSTEM AND IMAGING METHOD USING THE SAME}

The present invention relates to a variable shape adaptive positron emission tomography apparatus and a photographing method using the same. More particularly, the present invention relates to a variable shape adaptive positron emission tomography apparatus and a photographing method using the same, which can implement a variable shape by rotating a rotating part to which a gamma ray detector is attached so as to correspond to the size of a subject area.

Positron emission tomography (PET), or radioisotopes used in PET, is an isotope in an unstable state, with fewer neutrons constituting the nucleus than stable isotopes. This unstable nucleus is stabilized by accepting one orbital electron around it, converting protons into neutrons, or releasing one positron from protons into neutrons. Radioactive isotopes used in PET are positron emitters, which are stabilized through positron emission.

The most important physical phenomenon in understanding the principle of PET is the generation of two gamma rays due to twin extinction. Since the positron released from the nucleus is positively charged, it interacts with the nucleus and orbital electrons of the surrounding atoms and loses its kinetic energy initially and eventually meets and disappears by about 1 mm. At this time, two gamma rays having an energy of 511 keV corresponding to the static mass of the positron and the electron are simultaneously emitted in opposite directions, and the angle between the two gamma rays is always almost opposite to 180 degrees.

The key function of the PET system is to detect two gamma rays simultaneously generated by pair decay. The line connecting the positions where two gamma rays are detected in PET is called a line of response (LOR). A sinogram is obtained when the detection frequency for each response line is aligned with the distance and angle from the center of the detection ring. Data can be obtained to enable tomographic image reconstruction.

As such, unlike single-photon images, PET has excellent sensitivity because it can obtain information on the direction and location of gamma rays without a mechanical collimator. This allows for rapid whole body scans even with small amounts of radioisotopes.

In PET, scintillation detectors are generally used to detect gamma rays. In order to detect 511 keV gamma rays having higher energy than single photon images, not only the density of the scintillation crystal but also the atomic number must be high and the sensitivity must be good. In addition, the reaction rate of the scintillation crystal should be fast because it is necessary to determine whether two gamma rays occur simultaneously within a very short time (a few ns).

In addition, the amount of light generated in the scintillation crystal is high, the energy, space, and time resolution is excellent. As scintillation crystals with these conditions, LSO, LYSO, GSO, LuYAP, and BGO are used in clinical and preclinical PET.

One of the physical factors that lead to the degradation of PET is the uncertainty due to non-collinear annihilation. This is caused by the fact that the sum of momentum is not exactly zero because the two particles are not completely stopped when the positron and the electron combine. This means that two gamma rays are emitted with uncertainty of about ± 0.25 ° from 180 °. do. The uncertainty of this emission angle brings a position error of '0.0022 × D' (D: ring diameter), which is about 2 mm for a scanner with a diameter of 80 cm. Therefore, it can be seen that the diameter of the PET detection ring should be as small as possible in order to minimize the deterioration of the resolution caused by nonlinear extinction. However, when the diameter of the PET detection ring is smaller, the resolution of the peripheral field of view due to parallax error is deteriorated.

As a result, in order to improve the spatial resolution of PET, the diameter of the detection ring should be minimized (to reduce errors due to nonlinear extinction), and the cross-sectional area of the scintillation crystal should be reduced. In order to improve the sensitivity, the scintillation ratio as well as the scintillation detection efficiency and the solid angle of the PET cylinder should be maximized. In order to improve the solid angle of gamma ray detection, the cylinder diameter may be reduced while maintaining the length of the cylinder including the detection ring. In addition, in order to improve the detection efficiency of the scintillator, the scintillator length should be increased. However, as mentioned above, the longer the scintillator length, the lower the resolution at the periphery due to parallax error.

In consideration of the above-described parameters for resolution and sensitivity, it may be a way to increase the resolution and sensitivity to have a photographing apparatus suitable for the size and use of the subject.

Therefore, all commercially available clinical PET is a general-purpose scanner that can be used throughout the whole body. The detector ring diameter of the whole body PET is about 80 to 90 cm, and a flash having a cross-sectional area of (4 to 6) x (4 to 6) mm ² is used. The crystals have a spatial resolution of about 4-6 mm. In rare cases, PET for brain use uses a 40 cm diameter detector ring to improve resolution and sensitivity. In recent years, high-performance PET systems for topical imaging such as PET for breast are being used clinically.

Currently, many molecular imaging studies have been conducted mainly in small animals as an intermediate step between in vitro studies and clinical studies in humans. A PET system for small animals is needed. However, clinical PET scanners have sufficient resolution and It does not have sensitivity. Therefore, small animal PET scanners with high resolution of 1 to 2 mm and sensitivity of more than a few percent are needed.

As such, PET requires separate scanners with different diameters and scintillation crystal cross-sections, but each of them is expensive equipment ranging from 1 to 3 billion won. have.

Accordingly, the present invention has been made to solve the above problems, and the object of the present invention is to provide a spatial resolution and sensitivity by providing a photographing device condition for each subject in implementing a PET device necessary for realizing a photographing purpose. The present invention provides a variable shape adaptive positron emission tomography apparatus equipped with a gamma ray detector which can be increased, and a photographing method using the same.

In addition, another object of the present invention is a variable shape adaptive positron emission tomography apparatus equipped with a gamma ray detector that can be implemented in a single PET system to reduce the cost even if several PET devices are required according to the shooting purpose and use. And to provide a photographing method using the same.

An object of the present invention as described above is provided on one side of the rotatable first rotating shaft 30, the rotating wing 20 and the rotating wing 20 connected to the first rotating shaft 30 to detect one or more gamma rays One or more pivots (1) consisting of a detector (10); A driving unit 3 connected to the first rotating shaft 30 of the rotating unit 1 to drive the rotating unit 1; An arithmetic and control unit 5 connected to the gamma ray detector 10 for calculating a generation position of the gamma ray; And a display unit 6 connected to the operation control unit 5 to display an image of the subject 50. The at least one rotating unit 1 may include at least one detection surface of the gamma ray detector 10 available for detection. While rotating toward the center of the subject area 40 in correspondence with the size of the subject area 40, the at least one first pivot 30 maintains a predetermined angle around the subject 50 and is circumferentially shaped. It can be achieved by providing a variable shape adaptive positron emission tomography device characterized in that the arrangement.

In addition, the variable shape adaptive positron emission tomography apparatus is connected to the driving unit 3, and the driving unit controls the rotational angle through the driving unit 3 so that at least one rotating unit 1 corresponds to the diameter of the subject area 40. It is preferable to further include a control unit (4).

Each gamma ray detector 10 preferably forms one side of a regular polygon arranged circumferentially with the subject area 40.

In addition, the regular polygon is a regular hexagon, each of the one or more rotating parts (1 ') is preferably provided with six gamma-ray detector (10).

The drive control unit 4 is configured such that the drive unit (4) has a diameter such that the diameter of the subject area 40 is any one of a maximum diameter, 3/4 diameter of the maximum diameter, 1/2 diameter of the maximum diameter, and 1/4 diameter of the maximum diameter. It is preferable to control the rotation of the first rotating shaft 30 through 3).

The regular polygon is an equilateral hexagon, and the one or more rotating parts 1 'are four or more when the diameter of the subject area 40 is one or more, and the one or more gamma ray detectors 10 available for detection are three quarter diameters. It is preferable to be controlled to be three in case of 3, 1/2 diameter and one in case of 1/4 diameter.

The at least one rotating part 1 'includes a rotating means for rotating the at least one gamma ray detector 10, which is not available for detection, about the second rotating shaft 20'b of the rotating wing 20'. It is preferable.

The rotation means includes: a hinge 21 provided between the rotation blade 20 'and the gamma ray detector 10; And an actuator for transmitting a mechanical force to the one or more gamma ray detectors 10.

The second pivot 20'b preferably includes a bent portion such that the second pivot 20'b coupled to the gamma ray detector 10 at the end of the pivot 20 'can be bent. In this case, the bent portion is preferably a ball joint 23.

Each of the at least one gamma ray detector 10 is preferably a scintillation detector including at least one scintillation crystal 110 and at least one photomultiplier tube 120. In addition, the scintillation detector preferably includes a light blocking film 130 formed on the outer surface.

In addition, the variable shape adaptive positron emission tomography apparatus may further include a support frame 2 connecting the first pivotal shaft 30 and the driving unit 3 through holes formed in one surface thereof.

The driving unit 3 preferably transmits the power of the driving unit 3 to the one or more rotating units 1 through one or more pulleys or one or more gears connected to the first rotating shaft 30.

The arithmetic and control unit 5 preferably collects information of one or more available gamma ray detectors 10 based on the control command of the drive control unit 4 to calculate the gamma ray generating position.

Preferably, the image of the subject 50 corresponds to the gamma ray generating position of the arithmetic and control unit 5.

On the other hand, an object of the present invention is the step of the drive control unit 4 determines the diameter of the subject area 40 on the basis of the user input as another category (S10); Determining, by the drive controller 4, the rotation angle of the pivot 1 corresponding to the diameter of the subject area 40 (S20); The driving controller 4 rotates each of the rotating units 1 to the central axis of the first rotating shaft 30 at a rotational angle through the driving unit 3 (S50); and the gamma ray detector 10 available for detection. It can be achieved by providing a variable shape adaptive positron emission tomography method characterized in that it comprises a; step (S60) of photographing the subject 50 through.

In the photographing step S60 of the subject 50, the operation controller 5 calculates the position of the gamma ray generated in the subject area 40 based on the information collected from the gamma ray detector 10 available for detection ( S62); And displaying, by the display unit 6, an image corresponding to the gamma ray generating position of the operation controller 5 (S64).

In addition, between the rotation angle determination step (S20) and the rotation unit rotation step (S50), the drive control unit 4 determines a gamma ray detector 10 that is not available for detection in response to the rotation angle (S30); And a step (S40) in which the gamma ray detector 10, which is not available for detection, is rotated about the second rotational shaft 20b.

According to the present invention can solve the problem of having a conventional PET device for each purpose and purpose to improve the spatial resolution and sensitivity, and to increase the spatial resolution and sensitivity by providing a photographing device conditions for each subject It works.

In addition, even if several PET devices are required according to the shooting purpose and use, it can be realized as a single PET system and can increase the service life of the flash detector which is not available, thereby reducing the cost.

<Configuration>

<J Example 1 >

In the first embodiment of the present invention, the rotating part 1 is composed of a gamma ray detector 10, a rotating wing 20 and a first rotating shaft 30, in particular six gamma ray detectors 10 It has a structure fixed to the pivoting blade 20. It will be described below with reference to the drawings.

1 is a perspective view showing a basic detection unit constituting the gamma ray detector 10. As shown in FIG. 1, the gamma ray detector 10 uses a scintillation detector, and the plurality of scintillation crystals 110 and a photomultiplier tube 120 (PMT) connected thereto detect a gamma ray having an energy of 511 KeV. This is necessary configuration. However, there are various detection units for detecting gamma rays and these may also replace the basic detection unit of FIG. 1. For example, a detection unit capable of measuring the depth of interaction (DOI), a detection unit using a flash crystal 110 of various layers having different properties, and a detection unit including an optical sensor.

In the present exemplary embodiment, the flash crystal 110 of LSO material is used, and the area and length of the flash crystal 110 may vary depending on the size of the subject 50 to be photographed, that is, the space required for photographing, depending on the subject area 40. have. In the embodiment of the present invention, in the case of the gamma ray detector 10 in which the diameter of the subject area 40 is available at 10 to 30 cm, the breast or the small breast having a length of 2 to 3 cm in (0.5 to 3) x (0.5 to 3) mm ² A scintillation crystal 110 suitable for animal imaging is used. (2 to 4) × (2 to 4) mm ² for the additional gamma ray detector 10 whose diameter of the subject area 40 is available at 30 to 50 cm. Use a scintillation crystal 110 suitable for brain imaging of 2-3 cm in length. In addition, in the case of the additional gamma ray detector 10 having a diameter of 50 to 90 cm in the subject area 40, a flash crystal suitable for whole body imaging having a length of 2 to 3 cm in (4 to 6) x (4 to 6) mm ² ( 110).

FIG. 2 is a cross-sectional view illustrating a longitudinal axis of the gamma ray detector 10 in which a basic detection unit as shown in FIG. 1 is collected. In the embodiment of the present invention, one gamma ray detector 10 was used as a rectangular parallelepiped having a width of 53 mm and a height of 57 mm, respectively. The gamma ray detector 10 may have a large number of small sized basic detection units and form a detection ring densely to improve spatial resolution and sensitivity. Specifically, in the case of spatial resolution, variables such as the size of the scintillation crystal 110 constituting the detection ring are small and the diameter of the detection ring must be small, and in the case of the sensitivity, the shape ratio of the scintillation crystal 110 and the subject ( Variables such as the solid angle of the detection ring surrounding 50) must be large. Therefore, as shown in FIG. 2, the gamma ray detector 10 is configured by closely disposing the gap between the basic detection units so as not to generate a gap and using a plurality of the basic detection units.

In the case of the light blocking film 130, the surface of the light detector is formed of lead (Pb) or the like to block light among the gamma ray detectors 10 to avoid interference of adjacent light.

3 is a front view schematically showing the pivoting part 1 of the first embodiment according to the present invention and an enlarged perspective view of a part of the gamma ray detector 10. The rotating unit 1 includes a gamma ray detector 10, a rotating wing 20, and a first rotating shaft 30, and six gamma ray detectors 10 are fixed to each rotating unit 1. .

The gamma ray detector 10 is as described in FIGS. 1 and 2, and the rotor blade 20 is fixed to a plurality of gamma ray detectors 10 in a straight line with the rotor blade 20 so as to withstand the load at the time of rotation. Light weight, high strength 7075 duralumin and the like are used.

Figure 4 is a front view schematically showing a first shape of the variable shape of the first embodiment according to the present invention. Each of them has a regular hexagonal shape composed of six rotating parts 1 each having six gamma ray detectors 10. As shown in FIG. 5, the first shape has the largest diameter of the subject area 40. This is a general-purpose scanner that can be used over the whole body and is about 60 to 70 cm corresponding to the diameter of the subject area 40 of the whole body PET.

5 is a schematic view showing the overall configuration of the present invention. Referring to FIG. 5, the present invention has a basic configuration of the rotating unit 1, the support frame 2, the driving unit 3, the driving control unit 4, the operation control unit 5, and the display unit 6.

Support frame (2) to support the basic weight by connecting a spring (not shown) to one or more rotating parts (1) do not deviate from the elastic limit within the rotational angle on the inner surface.

The support frame 2 forms an outer shape of the apparatus according to the present invention, and is configured to form a hole in one inner surface thereof so that the first pivot shaft 30 of the pivot 1 penetrates the pulley or the gear. .

The driving unit 3 may use a geared motor to improve driving force to the place where the power for the rotation of the one or more rotating units 1 is formed. In addition, the drive corresponding to the rotation angle is possible based on the control command of the drive controller 4.

The driving controller 4 controls the driving of the driving unit 3, and outputs the gamma ray detector 10 information which is connected to the arithmetic controller 5 to be used for photographing and provided to the arithmetic controller 5.

The operation control unit 5 receives the gamma ray detector 10 information available for photographing from the drive control unit 4, receives the gamma ray detection signal from the available gamma ray detector 10, and aligns the distance and the angle from the center of the dozen hexagon. Output one data.

The display unit 6 displays an image corresponding to the gamma ray generating position based on the data received from the arithmetic and control unit 5.

6 is a front view schematically showing a second shape among the variable shapes of the first embodiment according to the present invention. The second shape is a shape rotated at a rotation angle of about 5 ° from the first shape. As shown in FIG. 6, the second shape has a diameter of the subject area 40 about 50 to 60 cm. Even when the size of the subject 50 is small among the whole body scanners, it may be used when the body size is small such as a child.

7 is a front view schematically showing a third shape of the variable shape of the first embodiment according to the present invention. The third shape is a shape rotated at a rotation angle of about 15 ° from the first shape. As shown in FIG. 7, the third shape has a diameter of the subject area 40 about 40 to 50 cm. In rare cases, PET for brain use uses a 40 cm diameter detector ring to improve resolution and sensitivity.

8 is a front view schematically showing a fourth shape of the variable shapes of the first embodiment according to the present invention. The fourth shape is a shape rotated at a rotation angle of about 25 ° from the first shape. As shown in FIG. 8, the fourth shape has a diameter of the subject area 40 about 30 cm. It is a configuration that can be used on parts of the body (eg breasts). It can also be used as small animal PET.

9 is a front view schematically showing a fifth shape of the variable shapes of the first embodiment according to the present invention. The fifth shape is a shape rotated at a rotation angle of about 35 ° from the first shape. As shown in FIG. 9, the fifth shape has a diameter of the subject area 40 about 10 cm. Therefore, it can be used as a small pet PET (eg rodents such as rats).

<J 2 Example >

In the second embodiment of the present invention, the rotating part 1 'has a configuration of a gamma ray detector 10, a rotating wing 20', and a first rotating shaft 30, in particular, four gamma ray detectors 10 are bent. It has a structure attached to each rotating blade 20 'which has a shape. Hereinafter, with reference to the drawings will be described with respect to the difference from the first embodiment.

The gamma ray detector 10 and its basic detection unit are the same as in the first embodiment as shown in Figs. The schematic overall configuration of the second embodiment is also the same as in FIG.

FIG. 10A is a front view schematically showing a pivoting portion 1 ′ of a second embodiment according to the present invention and an enlarged perspective view of the hinge coupler. FIG. In the enlarged perspective view, the hinge 21 is illustrated as a part of the gamma ray detector 10 attached to the pivoting blade 20 'and a configuration for rotating the same. The rotating part 1 'includes a gamma ray detector 10, a rotating wing 20' and a first rotating shaft 30, and four gamma ray detectors 10 are attached to each rotating part 1 '. It is. As shown in FIG. 10A, the pivoting blade 20 'includes a ball joint coupling shaft 20'a, a second pivot shaft 20'b, and a connecting shaft 20'c.

The gamma ray detector 10 is as described in FIGS. 1 and 2, and the pivoting wing 20 ′ is bent at the center thereof to prevent interference with the adjacent gamma ray detector 10 due to geometric characteristics during rotation. In addition, the pivoting blade 20 'may include a pivoting joint (not shown) in the central bending portion and may make the bending angle variable. Further, since the plurality of gamma ray detectors 10 are attached to the pivoting vanes 20 ', the pivoting vanes 20' are manufactured using 7075 duralumin and the like having high strength and light weight.

The hinge 21 connects the gamma ray detector 10 and the second pivot shaft 20'b of the rotor blade 20 'to the gamma ray detector 10 which is not available for detection. 20'b) is rotated around the central axis. On the contrary, the available gamma ray detector 10 can also be rotated to the subject area 40. In this case, each hinge 21 may receive power from an actuator (eg, a stepping motor, a servo motor, etc.) to rotate the gamma ray detector 10.

The ball joint coupling shaft 20'a is explained in the enlarged view of FIG. 10B. The connecting shaft 20'c is configured to connect power between the first rotating shaft 30 and the second rotating shaft 20'b.

In the enlarged perspective view of the hinge coupler of FIG. 10A, only the third gamma ray detector 13 and the fourth gamma ray detector 14 are shown, but the second gamma ray detector 12 also engages with the hinge 21 to perform the same rotation.

10B is an enlarged cross-sectional view of the bent portion to which the ball joint 23 is coupled in the pivoting portion 1 'of the second embodiment according to the present invention. It is the same structure as FIG. 10A, and only the coupling part of the ball joint 23 is expanded. Ball joint coupling shaft 20'a and second coupled to the first gamma-ray detector 11 in the two gamma-ray detectors 10 provided at the ends of the second rotational shaft 20'b of the rotating part 1 The second joint shaft 20'b coupled to the gamma ray detector 12 is configured to include a ball joint 23 to be bent. The ball joint 23 uses abrasion-resistant, lightweight, high strength 7075 duralumin as a material.

11 is a front view schematically showing a first shape of the variable shapes of the second embodiment according to the present invention. The first shape of the shape according to the embodiment of the present invention is a dozen hexagonal shape composed of twelve pivoting portions 1 each having four gamma ray detectors 10. As shown in FIG. 11, the first shape has the largest diameter of the subject area 40. Since the diameter of the subject area 40 of the PET is about 70 to 90 cm, it can be used throughout the whole body.

12 is a front view schematically showing a second shape among the variable shapes of the second embodiment according to the present invention. In the shape according to the embodiment of the present invention, it is composed of twelve rotating parts (1) having three gamma ray detectors (10) as the second shape. As shown in FIG. 12, the second shape is 3/4 diameter of the maximum diameter of the subject area 40, and is about 50 to 70 cm. It may be used when the size of the subject 50 is small (for example, a child) among the whole body scanners. Referring to FIG. 12, one gamma ray detector 10 (fourth gamma ray detector 14) which is not used for detection is rotated about the second rotational axis 20'b of the pivoting blade 20 'to be twelve. Make each side of the rectangle smaller. In this case, the bending angle may be changed to form a doveagonal shape by including a pivot joint (not shown) in the center portion of the pivot vane 20 '.

13 is a front view schematically showing a third shape of the variable shapes of the second embodiment according to the present invention. The third shape of the shape according to the embodiment of the present invention is composed of twelve rotation parts 1 having two gamma ray detectors 10. As shown in FIG. 13, the third shape is half the diameter of the maximum diameter of the subject area 40 and is about 30 to 50 cm. In rare cases, PET for brain use uses a 40 cm diameter detector ring to improve resolution and sensitivity. Referring to FIG. 13, two gamma ray detectors 10 (the third gamma ray detector 13 and the fourth gamma ray detector 14), which are not used for detection, are rotated about the second rotational axis 20'b. Each side of the dodecagon can be made smaller.

14 is a front view schematically showing a fourth shape of the variable shapes of the second embodiment according to the present invention. The fourth shape of the shape according to the embodiment of the present invention is composed of twelve rotation parts 1 each having one gamma ray detector 10. As shown in FIG. 14, the fourth shape is a quarter diameter of the maximum diameter of the subject area 40 and is about 10 to 30 cm. Therefore, it can be used as PET for small animals (eg rodents such as rats).

Referring to FIG. 14, each of the three gamma ray detectors 10 (the second gamma ray detector 12, the third gamma ray detector 13, and the fourth gamma ray detector 14), which are not used for detection, has a second rotational axis 20. 12 and 13 are rotated around 'b) so that each side of the dozen is smaller. In this case, the bending angle may be changed to form a doveagonal shape by including a pivot joint (not shown) in the center portion of the pivot vane 20 '. In this case, since there is interference with the adjacent gamma ray detector 10 which is not available, the ball joint coupling shaft 20'a and the second pivot shaft 20'b are formed by the ball joint 23 shown in FIG. 10B. This can be bent to avoid collisions.

<Shooting method>

<J Example 1 >

15 is a flowchart of a method of photographing a subject 50 using the first embodiment according to the present invention. A description with reference to FIG. 15 is as follows. Since the size of the subject 50 varies from several centimeters in diameter to several tens of centimeters in diameter, the subject 50 determines the diameter of the subject region 40 based on the user's input (S10). The rotation angle of the one or more pivots 1 corresponding to the diameter of the subject area 40 is determined (S20). For example, when the subject 50 is a brain requiring a diameter of 40 cm, it corresponds to the third shape of the first embodiment. Therefore, the drive controller 4 derives a rotation angle of about 15 degrees.

Next, the driving controller 4 rotates the at least one rotating unit 1 around the first rotating shaft 30 at a predetermined rotational angle of 15 ° through the driving unit 3 (S50).

Next, when one or more gamma ray detectors 10 used for detection form a regular hexagon toward the subject area 40, the subject 50 is photographed (S60).

In this case, the photographing step S60 of the subject 50 is performed in the following steps. First, when the gamma ray detector 10 that detects the gamma ray from the subject 50 outputs the flash detection information to the arithmetic controller 5, the arithmetic controller 5 receives the input and generates the gamma rays in the subject area 40. Calculate the (S62). Thereafter, the display unit 6 displays an image corresponding to the gamma ray generation position information received from the operation control unit 5 on the LCD or the like (S64).

Unlike the previous example, the subject 50 having a different diameter is also photographed in the above order, and the rotation angle of the subject 50 varies only according to the diameter of the subject region 40.

<J 2 Example >

16 is a flowchart of a method of photographing a subject 50 using the second embodiment according to the present invention. Hereinafter, a difference from the first embodiment will be described with reference to FIG. 16.

The diameter determining step S10 of the subject area 40 and the rotation angle determining step S20 of the pivoting part 1 are the same as in the first embodiment. For example, when the subject 50 is a brain requiring a diameter of 40 cm, the number of gamma ray detectors 10 available for detection is two and becomes the first gamma ray detector 11 and the second gamma ray detector 12. . As a result, the drive control unit 4 derives a rotation angle necessary for forming a dozen hexagon (third shape) having these as one side.

Next, the drive control unit 4 determines one or more gamma ray detectors 10 that are not available for detection in the regular dodecagon with a predetermined rotation angle. (S30) Then, each of the one or more rotation units 1 is available for detection. At least one gamma ray detector 10 which is not rotated is rotated about the second pivot 20'b as the central axis (S40). In the previous example, a second time in which two gamma-ray detectors 10 close to the first pivotal shaft 30, that is, the third gamma-ray detector 13 and the fourth gamma-ray detector 14, are connected by a hinge 21. It rotates along the coaxial 20'b.

Next, the driving controller 4 rotates the at least one rotating unit 1 around the first rotating shaft 30 to a position corresponding to the predetermined rotating angle through the driving unit 3 (S50).

Next, when at least one gamma ray detector 10 that is available for detection forms a dozen hexagon toward the subject area 40, the subject 50 is photographed (S60). In the previous example, only two gamma-ray detectors 10, i.e., the first gamma-ray detector 11 and the second gamma-ray detector 12, which are far from the first rotational shaft 30 form one side of each of the dodecagon. And available to shoot the brain. Here, the photographing step S60 of the subject 50 is the same as in the first embodiment.

In addition, the object 50 having a diameter different from the above example is photographed in the above-described order, and only the number of available gamma ray detectors 10 and the size of the dozen is different.

1 is a perspective view showing a basic detection unit constituting a gamma ray detector.

2 is a cross-sectional view showing a longitudinal axis of the gamma ray detector composed of a plurality of basic detection units.

Figure 3 is a front view schematically showing a rotating part of the first embodiment according to the present invention and an enlarged perspective view of some gamma-ray detector.

Figure 4 is a front view schematically showing a first shape of the variable shape of the first embodiment according to the present invention.

5 is a configuration diagram showing the overall configuration of the present invention.

Figure 6 is a front view schematically showing a second shape of the variable shape of the first embodiment according to the present invention.

Figure 7 is a front view schematically showing a third shape of the variable shape of the first embodiment according to the present invention.

8 is a front view schematically showing a fourth shape of the variable shapes of the first embodiment according to the present invention;

9 is a front view schematically showing a fifth shape of the variable shapes of the first embodiment according to the present invention;

Figure 10a is a front view schematically showing a pivoting portion of the second embodiment according to the present invention and an enlarged perspective view of the hinge coupler.

Figure 10b is an enlarged cross-sectional view of the bent portion is coupled to the ball joint of the rotating part of the second embodiment according to the present invention.

11 is a front view schematically showing a first shape of the variable shapes of the second embodiment according to the present invention;

12 is a front view schematically showing a second shape of the variable shapes of the second embodiment according to the present invention;

13 is a front view schematically showing a third shape of the variable shapes of the second embodiment according to the present invention;

14 is a front view schematically showing a fourth shape of the variable shapes of the second embodiment according to the present invention;

15 is a flowchart of a photographing method using a positron emission tomography apparatus of a first embodiment according to the present invention;

16 is a flowchart of a photographing method using the positron emission tomography apparatus of the second embodiment according to the present invention.

<Drawing number of main part>

1, 1 ': rotating part

2: support frame 3: drive unit 4: drive control unit 5: operation control unit 6: display unit

10: gamma ray detector

11: first gamma ray detector 12: second gamma ray detector

13: The third gamma ray detector 14: The fourth gamma ray detector

20, 20 ': Rotating wings

20'a: Ball joint coupling shaft 20'b: Second rotation shaft 20'c: Connecting shaft

21: hinge 23: ball joint

30: first pivot 40: subject area 50: subject

110: scintillation crystal 120: photomultiplier tube (PMT) 130: light blocking film

Claims (19)

Rotating first rotating shaft 30, the rotating wing 20 connected to the first rotating shaft 30 and the one or more provided on one side of the rotating wing 20 gamma ray detector 10 for detecting the gamma ray One or more pivots 1; A driving unit (3) connected to the first rotating shaft (30) of the rotating unit (1) to drive the rotating unit (1); An arithmetic and control unit 5 connected to the gamma ray detector 10 to calculate a generation position of the gamma ray; and And a display unit 6 connected to the operation control unit 5 to display an image of the subject 50. The at least one pivoting unit 1 is rotatable in correspondence with the size of the subject area 40 while the detection surface of the at least one gamma ray detector 10 available for detection is directed toward the center of the subject area 40, The at least one first pivotal shaft (30) is a variable shape adaptive positron emission tomography device, characterized in that arranged in a circumferential shape maintaining a constant angle around the subject (50). The method of claim 1, And a driving control unit 4 connected to the driving unit 3 and controlling the rotation angle through the driving unit 3 so that the at least one rotating unit 1 corresponds to the diameter of the subject area 40. A variable shape adaptive positron emission tomography apparatus, characterized in that. The method of claim 2, wherein each gamma ray detector 10, Adaptive positron emission tomography apparatus, characterized in that to form one side of the regular polygonal circumferentially arranged with the subject area (40). The method of claim 3, wherein The regular polygon is a regular hexagon, Adaptive shape positron emission tomography apparatus, characterized in that each of the one or more rotating parts (1) comprises six gamma-ray detectors (10). 4. The driving control unit 4 according to claim 3, Through the drive unit 3 such that the diameter of the subject area 40 is any one of a maximum diameter, 3/4 diameter of the maximum diameter, 1/2 diameter of the maximum diameter, and 1/4 diameter of the maximum diameter. Adaptive shape positron emission tomography apparatus, characterized in that for controlling the rotation of the first rotating shaft (30). The method of claim 5, The regular polygon is an equilateral polygon, The at least one rotating part 1 ', The at least one gamma ray detector 10 available for detection is four when the diameter of the subject area 40 is the maximum diameter, three when the 3/4 diameter, two when the 1/2 diameter, and The variable shape adaptive positron emission tomography apparatus, characterized in that controlled to be one when the 1/4 diameter. The method according to claim 1, wherein the at least one pivot 1 ' And a rotating means for rotating the at least one gamma ray detector 10, which is not available for detection, about the second pivot shaft 20'b of the pivoting blade 20 '. Positron emission tomography. The method of claim 7, wherein the rotating means, A hinge 21 installed between the pivoting blade 20 'and the gamma ray detector 10; And Adaptive quantum emission tomography apparatus comprising a; actuator for transmitting a mechanical force to the at least one gamma ray detector (10). The method of claim 7, wherein the second rotating shaft 20'b, Adaptive positron emission tomography apparatus characterized in that it comprises a bent to bend the second rotating shaft (20 'b) coupled to the gamma ray detector (10) at the end of the rotating wing (20'). The method of claim 9, Adaptive bending positron emission tomography apparatus, characterized in that the bent portion (23). The method of claim 1, wherein each of the one or more gamma ray detectors 10 Adaptive positron emission tomography device characterized in that the flash detector comprising at least one scintillation crystal 110 and at least one photomultiplier tube (120). The method of claim 11, wherein the scintillation detector, Adaptive shape positron emission tomography apparatus comprising a light blocking film 130 formed on the outer surface. The method of claim 1, Adaptive positron emission tomography apparatus, characterized in that it further comprises a support frame (2) for connecting the first rotating shaft (30) and the drive unit (3) through a hole formed in one surface. The method of claim 1, wherein the drive unit 3, Adaptive shape positron emission tomography, characterized in that for transmitting the power of the drive unit 3 to the at least one rotating unit 1 through at least one pulley or at least one gear connected to the first rotating shaft (30). Device. The method of claim 1, wherein the operation control unit 5, Adaptive shape positron emission tomography apparatus, characterized in that to collect the information of the available gamma ray detector (10) based on the control command of the drive control unit (4) to calculate the gamma ray generation position. According to claim 1, The image of the subject 50, Adaptive positron emission tomography apparatus, characterized in that corresponding to the gamma-ray generating position of the operation control unit (5). Determining, by the driving controller 4, the diameter of the subject area 40 based on a user input (S10); Determining, by the drive controller 4, the rotation angle of the pivot unit 1 corresponding to the diameter of the subject area 40 (S20); The driving control unit 4 rotating the respective rotating units 1 to the central axis at the rotational angle through the driving unit 3 (S50); and And a step (S60) of photographing the subject (50) through the gamma ray detector (10) available for detection. The method of claim 17, wherein the photographing of the subject 50 (S60), Calculating, by the calculation control unit 5, the position of the gamma ray generated in the subject area 40 based on the information collected from the gamma ray detector 10 available for the detection (S62); And And a display unit (6) displaying an image corresponding to the gamma ray generating position of the arithmetic and control unit (S64). The method of claim 17, Between the rotation angle determination step (S20) and the rotation unit rotation step (S50), Determining, by the drive controller 4, a gamma ray detector 10 that is not available for detection in response to the rotation angle (S30); and And a step (S40) of rotating the gamma ray detector (10), which is not available for detection, about the second pivot shaft (20b).

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