KR100618628B1 - Pet detector provided with optical fibers and combined mri-pet system using the same - Google Patents

Abstract

The present invention discloses an MRI-PET fusion system having a structure provided inside a cylindrical gantry of a magnetic resonance imaging apparatus (MRI) independently of a scintillation detector of a positron emission tomography apparatus (PET). The scintillation detector comprises: a scintillation detector having a structure in which a plurality of scintillation crystal arrays for converting radiation according to positron emission into light are arranged in a ring shape; A plurality of optical fiber groups connected to each of the plurality of scintillation crystal arrays to transfer the converted light to optical devices of a PET device installed outside the MRI device; And a conveying means for sliding the scintillation detector into and out of the gantry of the MRI device. In the MRI-PET fusion system, each of the MRI device and the PET device can be divided drive, as well as to drive both at the same time to acquire the MRI image and PET image at the same position without the movement of the patient to enable precise diagnosis of the lesion Do.

PET-MRI fusion system, scintillation detector, positron, optical fiber, optical element

Description

PET scintillation detector with optical fiber and MRI-PET fusion system using same {PET DETECTOR PROVIDED WITH OPTICAL FIBERS AND COMBINED MRI-PET SYSTEM USING THE SAME}

1A and 1B are schematic views of the construction of an MRI-PET fusion system according to the present invention.

2 is a perspective view of a flash detection unit for a positron emission tomography apparatus according to the present invention;

3 is a front view of a flash detector of the flash detector.

4 is a perspective view of a flash crystal array;

5 is a schematic diagram showing a connection state between a scintillation crystal array and an optical fiber group.

FIG. 6 is an enlarged view of portion A of FIG. 2; FIG.

7 is a cross-sectional view of an optical fiber group bundle for light transmission.

8 is a sectional view taken along the line B-B in FIG. 2;

9A and 9B are a perspective view and a front view of a reel for winding the bundle of optical fiber groups.

10 is a block diagram illustrating an image acquisition and processing procedure in an MRI-PET apparatus according to the present invention.

<Description of Symbols for Major Parts of Drawings>

100: positron emission tomography apparatus (PET apparatus) 110: scintillation detector

120: scintillation detector 121: scintillation crystal array

121a: scintillation crystal unit cell 122: partition wall

130: transfer means 131: tube member

132: guide member 132a: guide groove

133: drive motor 133a: motor gear

134: connecting member 135: support roll

136: reel 136a: separation diaphragm

136b, 136b ': hole 140: bundle of optical fiber group

141: optical fiber group 141a: optical fiber

142, 142 ': protective layer 150: optical element

160: amplifier 170: analog to digital converter

180: shielding film 200: magnetic resonance imaging apparatus (MRI apparatus)

210: gantry 220: sequential memory circuit

230: patient table 240: gate modulation circuit

250: RF power amplifier 260: RF transmitter

270: RF receiver 280: preamplifier

290: phase amplifier 295: analog to digital converter

300: display

The present invention fuses the structure and function of magnetic resonance imaging (MRI) and positron emission tomography (PET) in the same place without changing the position of the patient. The present invention relates to an MRI-PET fusion system capable of simultaneously obtaining anatomical and functional images of a patient's tissue and a scintillation detector of a positron emission tomography apparatus used therein.

In diagnostics requiring cancer tumors or other precise lesion imaging, MRI devices can be used to obtain any anatomical tomography in vivo using magnetic fields generated by magnetic forces, and to release positrons to metabolites such as glucose. After the radioisotope is combined and administered to the human body, it is necessary to use a PET device that can acquire tomographic images by observing biochemical changes occurring in the human body.

On the other hand, after applying a high frequency signal of the same rotational speed to a hydrogen proton that is magnetized by a powerful external magnetic field and rotates at a constant frequency, such as an MRI device, it receives a weak signal obtained from a positron, that is, a signal by a magnetic resonance phenomenon. In the device, when the image detection unit of the PET device is inserted into the MRI device, it is impossible to obtain a desired image due to the high noise of the electric field and the frequency due to the strong magnetic field of the MRI device.

Due to the problem that the signal disturbance occurs in the detection unit of the PET device under the influence of the magnetic field of the MRI device, conventionally, the PET device is installed and operated in an independent space shielded by the magnetic field. Therefore, in order to obtain an MRI image for obtaining an anatomical image of a living body and a PET image for obtaining a functional position image at an active site of a lesion, a patient must be moved to a different place.

In this case, the patient's condition is easy to change due to a long moving time for changing and measuring the measurement location, and thus, it is difficult to precisely diagnose the location of the lesion by reading images separately from both devices. In addition, since the measurement sites must be separated from each other, the diagnostic time is long, and the installation cost for both devices increases.

The present invention has been made to solve the above problems, by providing a flash detection unit of the positron emission tomography apparatus in the magnetic resonance imaging apparatus, anatomical images of the patient tissue in the same place without changing the position of the patient and By providing functional images at the same time, it provides an MRI-PET fusion system that can increase the precision of lesion diagnosis and significantly reduce the time required for diagnosis.

Another object of the present invention is to provide a flash detection unit of the positron emission tomography apparatus provided in the magnetic resonance imaging apparatus.

The gist of the present invention for achieving the above object is as follows.

(1) A MRI-PET fusion system having a structure in which a scintillation detector of a positron emission tomography device (PET) is independently provided inside a cylindrical gantry of a magnetic resonance imaging device (MRI),

The scintillation detector comprises: a scintillation detector having a structure in which a plurality of scintillation crystal arrays for converting radiation according to positron emission into light are arranged in a ring shape; A plurality of optical fiber groups connected to each of the plurality of scintillation crystal arrays to transfer the converted light to optical devices of a PET device installed outside the MRI device; MRI-PET fusion system, characterized in that it comprises a transport means for sliding the scintillation detector into and out of the gantry of the MRI device.

(2) The MRI-PET fusion system according to (1), wherein the scintillation crystal array is provided with a partition wall for preventing cross talk between scintillation crystal unit cells.

(3) The transfer means includes a drive motor; A guide member, a part of which protrudes out of the opening of the gantry and is fixedly supported; An MRI-PET fusion system according to (1), characterized in that it comprises a tube member which is guided and slid out of the guide member by the drive motor with the flash detector mounted at one end thereof.

(4) The MRI-PET fusion system according to the above (3), wherein a plurality of grooves are formed in the longitudinal direction outside the guide member to guide the plurality of optical fiber groups.

(5) The MRI-PET fusion system according to the above (1), further comprising at least one reel installed outside the MRI apparatus to wind the plurality of optical fiber groups.

(6) A flash detection unit of a positron emission tomography apparatus for fusing a positron emission tomography apparatus with a magnetic resonance imaging apparatus,

A scintillation detector having a structure in which a plurality of scintillation crystal arrays for converting radiation according to positron emission into light are arranged in a ring shape; A plurality of optical fiber groups connected to each of the plurality of scintillation crystal arrays to transfer the converted light to an optical device of a PET device installed outside the MRI device; A transport means for sliding the scintillation detector into and out of the gantry of the MRI apparatus,

The scintillation detector of the positron emission tomography apparatus (PET) is independently formed integrally inside the cylindrical gantry of the magnetic resonance imaging apparatus (MRI).

(7) The scintillation detector of the positron emission tomography apparatus according to (6), wherein the scintillation crystal array is provided with a partition wall for preventing cross talk between scintillation crystal unit cells.

(8) The transfer means includes a drive motor; A guide member, a part of which protrudes out of the opening of the gantry and is fixedly supported; And a tube member which is guided and slid out of the guide member by the drive motor in a state where the scintillation detector is mounted at one end thereof. The flash detector of the positron emission tomography apparatus according to (6) above.

(9) The flash detection unit of the positron emission tomography apparatus according to (8), wherein a plurality of guide grooves for guiding the plurality of optical fiber groups in the longitudinal direction are formed on the outer circumferential surface of the first tube member.

The present invention solves the conventional problem that the two devices must be installed and driven in a separate position in time due to the disturbance of the signal detection system provided in the PET device due to the influence of the magnetic field generated in the MRI device. There is this.

The core of the method of fusing the MRI device and the PET device is that each unit cell of a plurality of flash crystal arrays that form a part of the PET device, that is, the glare detector is separated from the PET device and integrally formed in the MRI device and constitutes the flash detector By connecting the optical fiber to the optical fiber, the light emitted from the unit cell used to acquire the PET image is collected by using the optical fiber and sent to an external PET device which is not affected by the magnetic field to perform signal processing.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the preferred embodiment of the present invention described below with reference to the accompanying drawings, the general matters related to MRI device or PET device that does not constitute the technical gist of the present invention as described above is not unclear the configuration of the present invention It is omitted suitably in the inside.

Figures 1a and 1b is a schematic configuration diagram of the MRI-PET fusion system according to the present invention, Figure 1a is a state where the flash detection portion of the PET device is inserted into the MRI device, Figure 1b shows the state pulled out of the MRI device, respectively . MRI-PET fusion system according to the present invention, the flash detection unit 110 of the PET device 100 is characterized in that the structure is installed integrally inside the cylindrical gantry 210 of the MRI device 200, MRI device Images obtained by driving each of the 200 and the PET device 100 alone or simultaneously are displayed on the display 300 by being alone or synthesized with each other.

At the inlet of the gantry 210, a patient table 230 that is transported into and out of the gantry 210 is installed in a state in which the patient 400 is loaded. The scintillation detector 110 is inserted from the opposite side of the patient table 230 based on the gantry 210, and the tube member 131 having the scintillator detector 120 attached to the front end is gantry 210 to acquire the PET image. Transported in and out. In this case, the tube member 131 is inserted into the gantry 210 in a form including the patient table 230 therein.

2 is a perspective view of the flash detection unit 110 according to the present invention. The scintillation detector 110 according to the present invention includes an annular scintillation detector 120 and a scintillation detector 120 for converting radiation generated from the patient (400 in FIG. 1) into light according to positron emission. A plurality of optical fiber group 141 for transmitting the light to the outside. The scintillation detector 120 is slid into and out of the gantry 210 of the MRI apparatus 200 by a transfer means (130 in FIG. 8). For reference, in FIG. 2, the housing of the PET device illustrated in FIG. 1 is omitted to clarify the overall configuration of the flash detection unit 110.

3 is a front view of the scintillation detector 120 of FIG. 3. The scintillation detector 120 is attached to the front end of the tube member 131 of the transfer means 130 by using a plurality of scintillation crystal array 121 in an annular arrangement using an epoxy (not shown).

4 is a perspective view of the scintillation crystal array 121. One scintillation crystal array 121 has a structure in which a plurality of scintillation crystal unit cells 121a are stacked, and flashes of light generated from scintillation crystal cells by radiation are adjacent between the scintillation crystal unit cells 121a. In order to prevent the influence (cross torque) on a crystal cell, the partition wall 122 is formed.

5 is a schematic diagram illustrating a connection state between the scintillation crystal array 121 and the optical fiber group 141. One optical fiber 141a is connected to each of the unit cells 121a constituting the scintillation crystal array 121 of FIG. 4, and a plurality of such optical fibers 141a are collected to form one optical fiber group 141. It corresponds to the flash crystal array 121. The optical fiber group 141 is covered with a protective layer 142, and a plurality of optical fibers 141a corresponding to the number of unit cells 121a constituting one scintillation crystal array 121 inside the protective layer 142. Is present. For example, in the case of the 8 x 8 array 121, the total number of optical fibers connected is 64.

6 is an enlarged view of a portion A of FIG. 2, and FIG. 7 is a cross-sectional view of the optical fiber group bundle for light transmission. 6 and 7, a single optical fiber group 141, which is a collection of optical fibers 141a, is connected to each scintillation crystal array 121, and several of the optical fiber groups 141 are connected to the protective layer 142 ′. The optical fiber group bundle 140 is coated to form a plurality of optical fiber group bundles 140, and the optical fiber group bundles 140 are regularly arranged in the longitudinal direction on the inner wall of the tube member 131 and extend outwardly.

 On the other hand, the tube member 131 is guided and transported by the guide member 132 fixed to the housing (not shown) of the PET device. The guide member 132 may be fixed to the PET housing by brackets or other means. At the outer circumference of the guide member 132, a guide groove 132a corresponding to the number of the optical fiber group bundles 140 is provided to guide the plurality of optical fiber group bundles 140 extending along the inner wall of the tube member 131. It is formed at regular intervals.

8 is a cross-sectional view of the portion B-B of FIG. 2. As can be seen in the figure, the optical fiber group bundle 140 is positioned and guided in a space formed between the concave groove 132a of the guide member 132 and the inner wall of the tube member 131.

Referring to FIG. 2, the connecting member 134 is fixedly installed on the outside of the tube member 131 by a bolt, and the connecting member 134 is connected to the drive motor 133 installed in the housing of the PET device 100. The tube member 131 is conveyed by engaging with the gear 133a installed at the end and performing linear motion in the axial direction of the gantry 210. In this embodiment, the connection member 134 is provided in a pair symmetrically from the outside of the tube member 131 for the purpose of preventing the flow of the tube member 131 by uniformly transmitting the force in the transfer operation process. It is illustrated, but not limited thereto.

In addition, in order to improve the engagement of the gear groove 134a formed in the gear 133a and the connecting member 134, the support roll 135 is symmetrically formed with the driving motor 133 based on the connecting member 134. It is preferable to install.

Subsequently, in the housing of the PET device 100, one or more reels 136 are provided for winding the plurality of optical fiber group bundles 140 guided along the grooves 132a of the guide member 132. Accordingly, when the transfer tube 131 is transferred to the outside of the MRI device gantry 210 by the operation of the driving motor 133, the fiber group bundle 140 may be prevented from being damaged by wrinkles.

9A and 9B are perspective and front views of the reel 136. Separation diaphragm 136a for separating and winding the plurality of optical fiber group bundles 140 in the longitudinal direction of the reel 136 is formed, and the central axis of the reel 136 partitioned by the respective diaphragm 136a. The outer circumferential surface is formed with a hole 136b, which serves as a communication path of the fiber group bundle 140, and the hole communicates with another hole 136b 'formed on the upper surface of the reel 136. The optical fiber group bundle 140 passing through the hole 136b exits another hole 136b 'and transmits light to the optical device (see 150 of FIG. 10) of the PET device.

Next, the image acquisition and processing in the MRI-PET fusion system according to the present invention will be briefly described.

10 is a block diagram illustrating an image acquisition and processing process in an MRI-PET apparatus according to the present invention.

First, the signal processing of the MRI system will be described. In operation of the image acquisition device, a sequential memory circuit 220 is provided as a circuit unit for controlling an entire signal. The gate modulation circuit 240 converts the sine wave from the existing signal generator into a magnetic resonance frequency determined by the static magnetic field. After that, amplitude modulation is performed on the selected excitation waveform to generate 90˚puls or 180˚puls. This modulated signal is supplied to the high frequency power amplifier 250. The high frequency signal of the resonance frequency supplied from the power amplifier 250 is amplitude-adjusted to the desired flip angle of the attenuator and transmitted to the irradiation coil 260 to excite a proton in a certain area in the living body.

The signal generated in this way is amplified by a head amplifier or preamplifier 280 of noise and amplified by the main amplifier 290 again. The main amplifier 290 is modulated to an intermediate frequency by a super heterodyne method and finally converted to an audible frequency band. The mid to low frequencies are converted by a double balanced mixer (DBM). This output is converted into a digital signal by an analog-to-digital converter 295 after the band is limited by a lowpass filter. The converted MRI digital signal and the digital ring signal generated from the PET are implemented as an image by a computer image reconstruction program and displayed on the display 300.

Next, a signal processing procedure in the PET system will be described. The scintillation crystal array 121 of the positron emission tomography apparatus emits light by gamma rays emitted in vivo. The emitted light is transmitted for signal processing to the PET 100 device installed outside the MRI magnetic field using the optical fiber 140 without loss of light in order to avoid noise due to the magnetic field and frequency of the MRI. The transmitted light is converted into an electrical signal by the optical device 150, and the converted minute electrical signal is amplified by the amplifier 160. The amplified analog signal is converted into a digital signal through an analog-to-digital conversion circuit 170 for fast image processing. The digital signal is implemented as an MRI-PET image synthesized through the reconstruction program 300 together with the MRI image signal.

The above description relates to specific embodiments of the present invention. It is to be understood that the above embodiments according to the present invention are for the purpose of explanation only and that various changes and modifications can be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, all such modifications and changes are to be understood as falling within the scope of the invention as set forth in the claims or their equivalents.

As described above, according to the MRI-PET fusion system according to the present invention, both MRI image and PET image can be obtained simultaneously as well as both, PET image without moving the patient by mounting the flash detection unit of the PET device inside the MRI device And MRI images can be acquired at the same time at the same time, so that the patient's lesion error due to the long examination time can be reduced and precise diagnosis can be made.

In addition, by using optical fiber to convert the optical signal required to acquire PET images from the outside of the MRI magnetic field to an electrical signal, it is possible to prevent signal distortion due to noise to obtain accurate images related to the lesion.

In addition, the installation cost can be significantly reduced by installing the MRI device and the PET device in the same place.

Claims (9)

As an MRI-PET fusion system having a structure in which a flash detection unit of a positron emission tomography device (PET) is independently provided inside a cylindrical gantry of a magnetic resonance imaging device (MRI), The scintillation detector comprises: a scintillation detector having a structure in which a plurality of scintillation crystal arrays for converting radiation according to positron emission into light are arranged in a ring shape; A plurality of optical fiber groups connected to each of the plurality of scintillation crystal arrays to transfer the converted light to optical devices of a PET device installed outside the MRI device; MRI-PET fusion system, characterized in that it comprises a transport means for sliding the scintillation detector into and out of the gantry of the MRI device. The method of claim 1, The scintillation crystal array MRI-PET fusion system, characterized in that the partition wall for preventing cross talk between the scintillation crystal unit cell. The method of claim 1, wherein the transfer means, A drive motor; A guide member, a part of which protrudes out of the opening of the gantry and is fixedly supported; And a tube member which is guided out of the guide member by the drive motor and slides with the flash detector mounted at one end thereof. The method of claim 3, wherein MRI-PET fusion system, characterized in that a plurality of grooves are formed in the longitudinal direction on the outside of the guide member to guide the plurality of optical fiber groups. The method of claim 1, MRI-PET fusion system is installed outside the MRI device further comprises at least one reel for winding the plurality of optical fiber groups. A flash detection unit of a positron emission tomography apparatus for fusing a positron emission tomography apparatus with a magnetic resonance imaging apparatus, A scintillation detector having a structure in which a plurality of scintillation crystal arrays for converting radiation according to positron emission into light are arranged in a ring shape; A plurality of optical fiber groups connected to each of the plurality of scintillation crystal arrays to transfer the converted light to an optical device of a PET device installed outside the MRI device; A transport means for sliding the scintillation detector into and out of the gantry of the MRI apparatus, The scintillation detector of the positron emission tomography apparatus (PET) is independently formed integrally inside the cylindrical gantry of the magnetic resonance imaging apparatus (MRI). The method of claim 6, The scintillation detector of the scintillation crystal array is provided with a partition wall for preventing crosstalk between the scintillation crystal unit cells. The method of claim 6, wherein the transfer means, A drive motor; A guide member, a part of which protrudes out of the opening of the gantry and is fixedly supported; And a tube member which is guided and slid out of the guide member by the drive motor with the flash detector mounted at one end thereof. The method of claim 8, And a plurality of guide grooves formed on the outer circumferential surface of the first tube member to guide the plurality of optical fiber groups in the longitudinal direction.

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