KR20150042489A - Interaction positioning method for Positron Emission Tomography and system using the same - Google Patents

Abstract

The present invention relates to a system and a method to discriminate a reaction position for a positron emission tomography apparatus. Specifically, the system includes: a PET detector which generates multiple analog output signals by detecting radiation emitted from radioactive pharmaceuticals injected into a body; multiple analog signal processing units which generate a trigger signal by receiving the multiple analog output signals of each channel from the PET detector and comparing the output signals with a signal of a preset threshold voltage; and a digital signal processing unit which acquires position information, energy information, and time information indicating detailed information of a radiation detection position by receiving an input of the trigger signal and responding to the reception. By the composition described above, the system and the method to discriminate a reaction position for a positron emission tomography apparatus are able to clearly discriminate pixels in the outer part of the effective field of view of an image by preventing an increase of thermal noise of a connected resistance even though the number of optical sensor channels increases.

Description

Field of the Invention [0001] The present invention relates to a method and system for determining a reaction site for a positron emission tomography (CT)

Field of the Invention [0002] The present invention relates to a method and system for determining a reaction position for a positron emission tomography apparatus, and more particularly, to a method and system for determining a reaction position for a positron emission tomography apparatus capable of easily obtaining a spatial resolution having a size smaller than that of an optical sensor will be.

In recent years, medical imaging devices that provide information necessary for accurate disease diagnosis by non-invasively displaying the inside of the living body in the form of images in accordance with the development of IT technology are widely used in the medical field. Of these medical imaging devices, there are X-ray CT (Computed Tomography), Magnetic Resonance Imaging (MRI) and nuclear medicine imaging devices. In particular, the X-ray computed tomography apparatus and magnetic resonance imaging provide detailed anatomical images of the human body, and the radioactive isotope nuclear medicine images provide images representing physiological phenomena in the human body.

Positron Emission Tomography (PET) (hereinafter referred to as PET) in nuclear medicine imaging apparatus is a system in which a radiopharmaceutical that emits a positron in a living body to be studied and diagnosed is injected by intravenous injection or inhalation, A positron emitted by a radiopharmaceutical labeled with a radioactive isotope in vivo detects gamma rays emitted from the outside of the living body in a back-to-back manner after binding with electrons. It is a video device to make.

As described above, the multiplexing circuit is used to receive the gamma ray signal detected through the detector and to implement the image using the input gamma ray. There are an Anger circuit, a PDC circuit, and the like in this multiplexing circuit.

First, in the Anger circuit, H. Anger proposed a method proposed by H. Anger in 1958, in which four resistors are connected to each channel of the optical sensor, and a plurality of output signals are divided into X +, X -, Y +, Y- signals to the last four channels.

Since the Anger circuit is constructed using only resistors, the implementation is simple, and a high spatial resolution image can be obtained by utilizing the light sharing phenomenon between the scintillation crystal and the optical sensor.

However, as the number of channels of the optical sensor increases, the linearity of the effective edge of the image decreases due to the increase of the thermal noise of the resistor connected to the circuit and the lack of light spread of the outer scintillation crystal, There is a problem in that it does not occur.

Also, unlike the above-described Anger circuit, a PDC (Position Decoder Circuit) is a method of multiplexing a signal from many channels through analog and digital signal processing of a signal detected the fastest among all channels detected in a detector block. The PDC circuit has a multiplexing rate that reduces the GAPD output signal of 32 channels to one GAPD output signal.

Such a PDC circuit has a high multiplexing ratio and has the advantage of reducing the probability of detecting the scattering coefficient generated inside the scintillation crystal. However, as the sensor channel and the scintillation crystal are combined in a one-to-one fashion, The spatial resolution can not be obtained.

In order to solve the problems of the prior art as described above, the present invention provides a method for identifying a reaction location for a positron emission tomography (PET) imaging apparatus, which clarifies pixel division of an image edge and easily obtains a spatial resolution smaller than a size of an optical sensor And systems.

According to an embodiment of the present invention, there is provided a system for identifying a reaction site for a positron emission tomography (PET) device, the system comprising: a detector for detecting radiation emitted from a radiopharmaceutical injected into a living body and generating a plurality of analog output signals; Detector; A plurality of analog signal processing units for receiving a plurality of analog type output signals for each channel from the PET detector and generating a trigger signal by comparing the signals with a signal according to a predetermined threshold voltage; And a digital signal processor for receiving the trigger signal and acquiring second position information, energy information, and time information indicating details of the radiation detection position in response to the trigger signal; .

More preferably, a scintillation crystal comprising an array type scintillator; And a photosensor in the form of an array that converts the scintillation signal received by the scintillation crystals to an electrical signal, wherein a PET detector is coupled between the adjacent two channels of the photosensor so that the middle row and the row of the scintillation crystals correspond to each other can do.

In particular, BGO (Bismuth Germanate), LSO (Lutetium Oxyorthosilicate), LYSO, Lutetium Aluminum Perovskite, LuYAP, gadolinium oxyorthosilicate), LGSO (lutetium gadolinium oxyorthosilicate), LuAG (lutetium aluminum garnet), GAGG (Gd 3 Al 2 Ga 3 O 123 Al 2 Ga 3 O 12), LFS (lutetium Fine Silicate), NaI (Tl) (Thallium doped Sodium Iodide) and CsI (Tl) (Thallium activated Cesium Iodide).

Particularly, a silicon photomultiplier (SiPM), a multi-pixel photon counter (MPPC), a CZT (CdZnTe), a CdTe, an Avalanche Photo Diode (APD), a PIN diode, a digital silicon photomultiplier A light source, and a light source.

A first preamplifier for receiving an analog type optical sensor output signal for a plurality of channels from the PET detector and amplifying the output signal so that the gain of the output signal is uniform; A signal synthesizer for receiving the plurality of analog-type output signals amplified at a uniform amplification rate from the first pre-amplifier and for synthesizing the plurality of analog-type output signals received; A comparator for receiving a synthesized signal output from the signal synthesizer and comparing the synthesized signal with a signal corresponding to a preset threshold voltage to generate a trigger signal; A second pre-amplifier unit for receiving the plurality of output signals from the first pre-amplifier unit, performing pulse shaping, and outputting the output signals; A switching unit receiving a pulse formulated from the second pre-amplifier unit, receiving a switching signal from the digital signal processor, and selecting and outputting the plurality of analog output signals in response to the switching signal; And an analog signal processing unit.

A control unit receiving the trigger signal generated from the comparison unit and generating first position information predicted to a radiation detection position based on a trigger signal input first among the input trigger signals; An AD converter for receiving a plurality of analog output signals from the analog signal processor selected by the switching unit and converting the analog output signals into a digital signal; And a time information generator for receiving the trigger signal generated from the comparison unit and generating time information at the time of radiation detection based on the trigger signal input first among the input trigger signals .

The controller may generate a switching signal to select one analog signal processing unit corresponding to the first position information among the plurality of analog signal processing units, and transmit the generated switching signal to the switching unit.

And an A / D converting unit for outputting second positional information indicating a detailed detection position of the radiation from the digital signal and energy information indicating an energy state at the time of detection of the radiation.

According to an aspect of the present invention, there is provided a method for identifying a reaction site for a positron emission tomography (PET) device, the method comprising detecting a radiation emitted from a radiopharmaceutical drug injected into a living body, ≪ / RTI > A plurality of analog signal processing units receiving a plurality of analog type output signals for each channel from the PET detector and generating a trigger signal by comparing the signals with a signal according to a predetermined threshold voltage; And a digital signal processing unit receiving the trigger signal and acquiring position information, energy information, and time information for a radiation detection position in response thereto; .

The first pre-amplification unit may receive the optical sensor output signal of the analog type for a plurality of channels from the PET detector and amplify the output signal so that the gain of the output signal is uniform. A signal combining unit receiving the plurality of analog-type output signals amplified by the first pre-amplifier unit, and synthesizing and outputting the plurality of analog-type output signals received; Receiving a synthesized signal output from the signal synthesizing unit and generating a trigger signal by comparing the synthesized signal with a signal corresponding to a preset threshold voltage; A second preamplifier unit receiving the plurality of output signals from the first preamplifier unit, performing pulse shaping, and outputting the output signals; And a switching unit receiving a pulse shaped from the second pre-amplifier unit, receiving a switching signal from the digital signal processor, and selecting and outputting a plurality of analog output signals for the channel selected by the switching signal; And generating a plurality of analog signal processing units including the trigger signal.

Preferably, the control unit receives the trigger signal generated from the comparison unit and generates first position information expected to be at the radiation detection position based on the trigger signal input first among the input trigger signals. A step of the AD conversion unit receiving a plurality of analog output signals input to the analog signal processing unit selected by the switching unit among the plurality of analog signal processing units and converting the analog output signals into digital signals; And a time information generating unit receiving the trigger signal generated from the comparing unit and generating time information at the time of detecting the radiation, wherein the digital signal processing unit acquires position information, energy information, and time information of the radiation detecting position Step < / RTI >

In particular, the controller generates a switching signal to select one analog signal processing unit corresponding to the first position information among a plurality of analog signal processing units, and transmits the generated switching signal to the switching unit, generates the first position information Process.

In particular, the AD conversion unit, which includes outputting second position information indicating a detailed detection position of the radiation from the digital signal and energy information indicating an energy state at the time of detection of the radiation, receives a plurality of analog output signals, Into a signal.

The system and method for identifying a reaction location for positron emission tomography of the present invention prevents an increase in the thermal noise of a connected resistor even if the number of photo sensor channels is increased, have.

In addition, the system and method for identifying a reaction location for a positron emission tomography (FPT) device of the present invention can achieve a spatial resolution corresponding to a size smaller than the size of a photosensor, by combining the middle row and the row of scintillation crystals between two adjacent channels of the photosensor There is an effect that can be.

1 is a block diagram of a reaction location determination system for a positron emission tomography (PET) system according to an embodiment of the present invention.
2 is a diagram showing the coupling between a scintillation crystal and a photosensor of a PET detector.
3 is a detailed block diagram of a reaction location determination system for positron emission tomography.
4 is a flowchart of a method of determining a reaction position for positron emission tomography according to another embodiment of the present invention.
5 is a diagram showing an example of dividing pixels of a flood image.
6 is a block diagram of the time resolution acquisition experiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, the present invention will be described in detail with reference to preferred embodiments and accompanying drawings, which will be easily understood by those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Hereinafter, a reaction location determination system for a positron emission tomography (PET) device according to an embodiment of the present invention will be described in detail with reference to FIG.

1 is a block diagram of a reaction location determination system for a positron emission tomography (PET) system according to an embodiment of the present invention.

As shown in FIG. 1, the reaction location determination system 100 for a positron emission tomograph of the present invention includes a PET detector 120, an analog signal processor 140, and a digital signal processor 160.

The PET detector 120 detects the radiation emitted from the radiopharmaceutical injected into the living body. The PET detector 120 includes a scintillation crystal 122 and an optical sensor 124. The scintillation crystals 122 are made of a scintillator in the form of an array wherein the scintillators are made of BGO (Bismuth Germanate), LSO (Lutetium Oxyorthosilicate), LYSO (Lutetium Yttrium Oxyorthosilicate), LuAP (Lutetium Aluminum Perovskite), LuYAP Perovskite), LaBr3 (Lanthanum Bromide) , LuI3 (Lutetium Iodide), GSO (gadolinium oxyorthosilicate), LGSO (lutetium gadolinium oxyorthosilicate), LuAG (Lutetium aluminum garnet), GAGG (Gd 3 Al 2 Ga 3 O 123 Al 2 Ga 3 O ₁₂ ), Lutetium Fine Silicate (LFS), Thallium-doped Sodium Iodide (Tl), and Thallium activated Cesium Iodide (CsI).

The optical sensor 124 converts the scintillation signal emitted from the scintillation crystal 122 into an electrical signal. The optical sensor 124 may be a silicon photomultiplier (SiPM), a multi-pixel photon counter (MPPC), a CZT CdZnTe), CdTe, APD (Avalanche Photo Diode), PIN diode, and digital silicon photomultiplier (dSiPM).

2 is a diagram showing the coupling between a scintillation crystal and a photosensor of a PET detector.

As shown in FIG. 2, the LYSO scintillation crystal is composed of a 6 × 6 array type 2 mm × 2 mm × 10 mm LYSO scintillation crystal and a 4 × 4 array type 3 mm × 3 mm GAPD optical sensor. The arrayed optical sensors are coupled such that the middle row and the row of the scintillation crystals 122 correspond to each other between two adjacent channels of the GAPD optical sensor.

Accordingly, when a gamma ray reaction occurs between the middle row and the row of scintillation crystals of the LYSO array type scintillation crystals, analog signals are generated in the two or four channels of the GAPD optical sensor, and four signals are applied to the anger position discrimination algorithm, As shown in FIG.

Referring back to FIG. 1, the analog signal processing unit 140 receives output signals of a plurality of analog types for each channel from the PET detector 120, and compares the analog output signals with a signal corresponding to a predetermined threshold voltage to generate a trigger signal. The analog signal processing unit 140 includes a first pre-amplifier unit 141, a signal synthesizer 143, a comparison unit 145, a second pre-amplifier unit 147, and a switching unit 149.

The first preamplifier 141 receives an analog type optical sensor output signal for a plurality of channels from the PET detector 120 and amplifies the output signal so that the gain of the output signal is uniform.

The signal synthesizer 143 receives the plurality of analog output signals amplified by the first pre-amplifier 141, synthesizes the plurality of analog output signals into a single signal, do.

The comparator 145 receives the synthesized signal output from the signal synthesizer 143 and compares the received synthesized signal with a signal according to a predetermined threshold voltage. When the synthesized signal exceeds a signal corresponding to the threshold voltage, Signal.

The second preamplifier 147 receives the plurality of output signals amplified by the first preamplifier 141, performs pulse shaping, and outputs the pulse signals.

The switching unit 149 receives the pulse shaped from the second pre-amplifier unit 147 and receives the switching signal from the digital signal processor 160. The switching unit 149 receives the switching signal from the plurality of channels in response to the received switching signal, And selects and outputs a plurality of analog output signals for the channel selected by the switching signal among the plurality of analog output signals.

The digital signal processor 160 receives the trigger signal from the plurality of analog signal processors 140, and acquires position information, energy information, and time information of the radiation detection position in response to the trigger signal. The digital signal processing unit 160 includes a control unit 162, an A / D conversion unit 164, and a time information generation unit 166.

The control unit 162 receives the trigger signal generated from the comparison unit 145 of the analog signal processing unit 140 and generates a trigger signal based on the first trigger signal input to the first position Information. The controller 162 generates a switching signal to select one analog signal processor 140 corresponding to the first position information among the plurality of analog signal processors 140 and outputs the generated switching signal to the analog signal processor 140 to the switching unit 149.

The AD conversion unit 164 receives a plurality of analog output signals from the analog signal processing unit 140 selected by the switching unit 149 among the plurality of analog signal processing units 140 and converts them into digital signals. At this time, the digital signal to be converted may have a size of 10 bits. In particular, the A / D converter 164 outputs second position information indicating a detailed detection position of the radiation from the digital signal and energy information indicating an energy state at the time of detection of the radiation. At this time, the A / D converter 164 may have a sampling rate of 80 MHz. The time information generation unit 166 receives the trigger signal generated from the comparison unit 145 and generates time information at the time of radiation detection based on the trigger signal input first among the input trigger signals.

The flow of data input / output from the above-described plurality of analog signal processing units and digital signal processing units can be confirmed more specifically with reference to FIG.

4 is a flowchart of a method for determining a reaction position for a positron emission tomography (PET) device according to an embodiment of the present invention.

As shown in FIG. 4, in the method of determining the reaction position for a positron emission tomography apparatus according to the present invention, the PET detector 120 detects radiation emitted from a radiopharmaceutical injected into a living body, (S210).

The first preamplifier 141 receives an analog type optical sensor output signal for a plurality of channels from the PET detector 120 and amplifies the output signal so that the gain of the output signal is uniform (S220).

The signal combining unit 143 receives the plurality of analog-type output signals amplified from the first pre-amplifier 141, and combines the received plurality of analog-type output signals into one signal to synthesize And outputs a signal (S230).

The comparator 145 receives the synthesized signal output from the signal synthesizer 143 and compares the received synthesized signal with a signal according to a predetermined threshold voltage. When the synthesized signal exceeds a signal corresponding to the threshold voltage, And generates a signal (S240).

The second preamplifier 147 receives the plurality of output signals amplified from the first preamplifier 141, performs pulse shaping, and outputs the amplified signals.

The switching unit 149 receives the pulse formulated from the second pre-amplifier unit 147, receives the switching signal from the digital signal processor 160, and receives the switching signal from the plurality of channels in response to the received switching signal, A plurality of analog output signals for the channel selected by the switching signal among the plurality of analog output signals are selected and output (S260).

Then, the control unit 162 receives the trigger signal generated from the comparison unit 145, and generates the first position information predicted to the radiation detection position based on the trigger signal input first among the input trigger signals ( S270).

Thereafter, the control unit 162 generates a switching signal to select one analog signal processing unit corresponding to the first position information among the plurality of analog signal processing units 140, and outputs the generated switching signal to the switching unit 149. [ (S280).

The AD conversion unit 164 receives a plurality of analog output signals from the analog signal processing unit 140 selected by the switching unit 149 among the plurality of analog signal processing units 140 and converts the analog output signals into digital signals S290). At this time, the A / D converter 164 may output second position information indicating a detailed detection position of the radiation from the digital signal and energy information indicating an energy state at the time of detection of the radiation.

Next, the time information generator 166 receives the trigger signal generated from the comparator 145 and generates time information at the time of radiation detection based on the trigger signal input first among the input trigger signals (S300 ).

Hereinafter, an experiment for verifying the accuracy of the radiation position obtained by using the reaction position discrimination method for positron emission tomography of the present invention will be described.

5 is a diagram showing an example of dividing pixels of a flood image.

First, the precondition for this experiment was as follows. A 1.3 MBq Na-22 standard dotted circle was irradiated to the PET detector module for about 3 minutes, and about one million events were stored according to the reaction location determination method for positron emission tomography do. At this time, the stored event is processed using MATLAB (mathworks, USA) for approximate position calculation using 4-bit digital data stored for each event and detailed position calculation using 4 ADC data. In order to enhance the contrast of the image, an energy window was applied based on the photopeak in each zone.

As shown in FIG. 5, data obtained by using a detector module, an analog and digital signal processor, and a data acquisition module, which combine an array type LYSO scintillation crystal and an array type GAPD optical sensor, are applied to the following Equation 1, . Thus, it can be seen that all the 36 points are clearly distinguished through the obtained flood image.

[Equation 1]

In this way, the median value between the maximum points of the obtained flood images is extracted to distinguish the pixel spaces, and the energy values of the divided pixels are calculated to obtain 36 energy spectra, and then the Gaussian curve approximation And the energy resolution was measured at a full width at half maximum (FWHM) of 511 keV. After extracting the line profile of each point of the flood image, the peak-to-valley ratio was measured and compared with the measured value of the conventional multiplexing method.

6 is a block diagram of the time resolution acquisition experiment.

As shown in FIG. 6, a PET detector module is constructed as a pair, and the spatial resolution is measured by locating 1.3 MBq, Na-22 standard dotted circle in the center.

In this time resolution experiment, we extracted time data of each event among 1 million data obtained by irradiating for about 3 minutes. Time spectrum was derived using MATLAB and time resolution was calculated by half width using Gaussian curve approximation.

In addition, the possibility evaluation test of the present invention was performed on the PET image.

In this experiment, the object to be imaged was rotated using a stepping motor, and a tomogram was taken using only a pair of detectors instead of the whole round PET system. The two capillaries are filled with approximately 3.7 MBq of F-18-FDG, then placed 2 mm apart from the center point of the pair of detectors and rotated 180 degrees at 15 degree intervals. Store one million events per rotation interval. All stored events are calculated in detector coordinates as if the entire PET system were constructed taking into account the angle of rotation. At this time, the 2D reconstruction method used 2D filtered backprojection (2D FBP), and normalization and coincidence coefficient correction were not performed.

In addition, the reaction location determination system and method for such a positron emission tomography apparatus can be stored in a computer-readable recording medium on which a program for executing by a computer is recorded. At this time, the computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer readable recording medium include ROM, RAM, CD-ROM, DVD 占 ROM, DVD-RAM, magnetic tape, floppy disk, hard disk, optical data storage, and the like. In addition, the computer-readable recording medium may be distributed to network-connected computer devices so that computer-readable codes can be stored and executed in a distributed manner.

The system and method for identifying a reaction location for positron emission tomography of the present invention prevents an increase in the thermal noise of a connected resistor even if the number of photo sensor channels is increased, have.

In addition, the system and method for identifying a reaction location for a positron emission tomography (FPT) device of the present invention can achieve a spatial resolution corresponding to a size smaller than the size of a photosensor, by combining the middle row and the row of scintillation crystals between two adjacent channels of the photosensor There is an effect that can be.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Do.

120: PET detector 140: Analog signal processor
160: Digital signal processor

Claims (14)

A PET detector for detecting radiation emitted from a radiopharmaceutical injected into a living body to generate a plurality of analog output signals;
A plurality of analog signal processing units for receiving a plurality of analog type output signals for each channel from the PET detector and generating a trigger signal by comparing the signals with a signal according to a predetermined threshold voltage; And
A digital signal processor for receiving the trigger signal and acquiring position information, energy information and time information indicating details of the radiation detection position in response to the trigger signal;
And a reaction location determining system for positron emission tomography.
The method according to claim 1,
The PET detector
A scintillation crystal made of a scintillator in the form of an array; And
An optical sensor in the form of an array for converting the scintillation signal received by the scintillation crystal into an electrical signal;
, ≪ / RTI &
And the middle row and the row of the scintillation crystals correspond to each other between two adjacent channels of the optical sensor.
3. The method of claim 2,
The scintillation crystals
(Lutetium Aluminum Perovskite), LuYAP (Lutetium Yttrium Aluminum Perovskite), LaBr3 (Lanthanum Bromide), LuI3 (Lutetium Iodide), GSO (Gadolinium oxyorthosilicate), BGO (Bismuth Germanate), Lutetium Oxyorthosilicate (LSO), Lutetium Yttrium Oxyorthosilicate ), LGSO (lutetium gadolinium oxyorthosilicate) , LuAG (lutetium aluminum garnet), GAGG (Gd 3 Al 2 Ga 3 O 123 Al 2 Ga 3 O 12), LFS (lutetium Fine Silicate), NaI (Tl) (Thallium doped Sodium Iodide ) And CsI (Tl) (thallium activated cesium iodide). The system for determining a reaction position for a positron emission tomography apparatus according to claim 1,
3. The method of claim 2,
The optical sensor
(SiPM), Multi-Pixel Photon Counter (MPPC), CZT (CdZnTe), CdTe, APD (Avalanche Photo Diode), PIN diodes, digital silicon photomultiplier (dSiPM) Wherein the reaction location determining system comprises:
The method according to claim 1,
The analog signal processing unit
A first preamplifier unit for receiving an analog type optical sensor output signal for a plurality of channels from the PET detector and amplifying the output signal so that the gain of the output signal is uniform,
A signal synthesizer for receiving the plurality of analog-type output signals amplified by the first pre-amplifier and synthesizing the plurality of analog-type output signals received and outputting the synthesized output signals;
A comparator for receiving a synthesized signal output from the signal synthesizer and comparing the synthesized signal with a signal corresponding to a preset threshold voltage to generate a trigger signal;
A second pre-amplifier unit for receiving the plurality of output signals from the first pre-amplifier unit, performing pulse shaping, and outputting the output signals; And
A switching unit receiving a pulse formulated from the second pre-amplifier unit, receiving a switching signal from the digital signal processor, and selecting and outputting the plurality of analog output signals in response to the switching signal;
And a reaction location determining system for positron emission tomography.
6. The method of claim 5,
The digital signal processing unit
A control unit receiving the trigger signal generated from the comparison unit and generating first position information predicted to a radiation detection position based on a trigger signal input first among the input trigger signals;
An AD converter for receiving a plurality of analog output signals from the analog signal processor selected by the switching unit and converting the analog output signals into a digital signal; And
A time information generating unit that receives the trigger signal generated from the comparing unit and generates time information at the time of radiation detection based on the trigger signal input first among the input trigger signals;
And a reaction location determining system for positron emission tomography.
The method according to claim 6,
The control unit
Wherein the controller generates a switching signal to select one analog signal processing unit corresponding to the first position information among a plurality of analog signal processing units and transmits the generated switching signal to the switching unit system.
8. The method of claim 7,
The AD conversion unit
Second position information indicating a detailed detection position of the radiation from the digital signal, and energy information indicating an energy state at the time of detection of the radiation are outputted to the reaction location determination system for positron emission tomography.
Detecting a radiation emitted from a radiopharmaceutical drug injected into a living body by a PET detector to generate a plurality of analog output signals;
A plurality of analog signal processing units receiving a plurality of analog type output signals for each channel from the PET detector and generating a trigger signal by comparing the signals with a signal according to a predetermined threshold voltage; And
The digital signal processing unit receiving the trigger signal and acquiring position information, energy information, and time information for the radiation detection position in response thereto;
Wherein the reaction location determining step includes the step of determining the reaction location of the positron emission tomography apparatus.
10. The method of claim 9,
Wherein the step of generating the plurality of analog signal processing unit trigger signals comprises:
Amplifying the output signal so that the gain of the output signal is uniform by receiving an analog type optical sensor output signal for a plurality of channels from the PET detector;
A signal combining unit receiving the plurality of analog-type output signals amplified by the first pre-amplifier unit, and synthesizing and outputting the plurality of analog-type output signals received;
Receiving a synthesized signal output from the signal synthesizing unit and generating a trigger signal by comparing the synthesized signal with a signal corresponding to a preset threshold voltage;
A second preamplifier unit receiving the plurality of output signals from the first preamplifier unit, performing pulse shaping, and outputting the output signals; And
Selecting a plurality of analog output signals for the channel selected by the switching signal and receiving the switching signal from the digital signal processing unit, and outputting the selected analog output signal;
The method of claim 1, further comprising the step of determining the location of the positron emission tomography apparatus.
11. The method of claim 10,
The step of acquiring position information, energy information and time information for the digital signal processing section
A control unit receiving the trigger signal generated from the comparison unit and generating first position information expected to be a radiation detection position based on a trigger signal input first among the input trigger signals;
A step of the AD conversion unit receiving a plurality of analog output signals input to the analog signal processing unit selected by the switching unit among the plurality of analog signal processing units and converting the analog output signals into digital signals; And
The time information generating unit receives the trigger signal generated from the comparing unit and generates time information at the time of detecting the radiation;
The method of claim 1, further comprising:
12. The method of claim 11,
The process of generating the first position information by the controller
Further comprising generating a switching signal to select one analog signal processing unit corresponding to the first position information among the plurality of analog signal processing units and transmitting the generated switching signal to the switching unit Determination of reaction position of teeth.
12. The method of claim 11,
The process of the AD conversion unit receiving a plurality of analog output signals and converting the analog output signals into digital signals
And outputting second position information indicating a detailed detection position of the radiation from the digital signal and energy information indicating an energy state at the time of detection of the radiation.
A computer-readable recording medium on which a program for executing a method according to any one of claims 9 to 13 is recorded.

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