CN210697662U - Cherotkoff event and gamma event coincidence imaging device - Google Patents

Abstract

A Cherotkoff event and gamma event coincidence imaging device is provided, the prior traditional positron emission imaging only detects gamma photons annihilated by positrons, and part of visible light data which can be acquired is lost. The utility model provides a contract koff's event accords with imaging device with gamma event includes that rich proton isotope injects module, many radiation detector module, many instances time and accords with module, system transfer function acquisition module and nuclide distribution image and rebuilds the module, and rich proton isotope injects the module for participating in physiology and biochemical process's material in the organism and mark, its main content is the background light outside the shielding organism to make the organism have the marker that can give out light, the utility model has the advantages of: the method has ultrahigh sensitivity, can explore more particle information, has higher system accuracy and imaging quantitative accuracy, meets design for resisting background light and self-luminous event time of organisms, and is favorable for reducing imaging background noise.

Description

Cherotkoff event and gamma event coincidence imaging device

Technical Field

The utility model relates to a biomedical diagnostic system, photoelectric signal processing and nuclear detection field especially relate to a chev-on-koff event accords with image device with gamma event.

Background

Positron Emission Tomography (PET) is a novel noninvasive medical imaging technique. PET is a non-invasive functional imaging, and is one of the important imaging modes in the fields of nuclear medicine and molecular imaging. Biochemical changes tend to precede anatomical changes in the early stages of disease onset, while PET is capable of dynamically and quantitatively measuring pathophysiological changes and metabolic processes in the human or animal body from the molecular level. By depicting the position distribution and the change of radioactivity of the radioactive tracer in the body, the metabolic level, biochemical reaction and functional activity of various organs and tissues in an animal or a human body can be noninvasively, quantitatively and dynamically evaluated, the method can be applied to early diagnosis and treatment stages of tumors, heart and brain system diseases and nervous system diseases, and plays a unique role in early detection of diseases, pathophysiological mechanism research, curative effect monitoring, prognosis evaluation and the like.

With the continuous and deep application of the PET instrument in clinical diagnosis and treatment, the medical community puts forward new requirements on the performance and functions of the PET instrument, prompts researchers of the PET instrument to develop new methods and technologies, and promotes the updating of the instrument from system design, hardware devices to image reconstruction links. Conventional PET loses a portion of the available visible light data for acquisition by detecting only gamma photons annihilated by positrons. In fact, when the emitted positron speed meets a certain condition, visible light photons and soft ultraviolet photons are emitted.

Therefore, in order to obtain an image with more diagnostic capability in view of the above technical problems, it is necessary to provide a 5-key koff event and gamma event coincidence imaging apparatus and method for acquiring single photon time information, so as to overcome the above drawbacks. Comprehensively capturing 7-dimensional information of angle (2-D), time (1-D), position (3-D) and energy (1-D) of a single positron event.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a koff event and gamma event coincidence imaging device, which can effectively read out the electrical signal samples of multiple photons of a positron event, and through multi-photon time coincidence, reject self-luminescence events, increase the signal-to-noise ratio of reconstructed images, and avoid the influence of baseline drift on the read-out signals.

In order to achieve the above object, the utility model provides a following technical scheme:

a method of conformal imaging of koff's events and gamma events, comprising the steps of:

s1: arranging a visible light photon detector and a gamma photon detector to obtain two different event attributes of a pulse data set of positron emission Cherotkoff effect photons, a gamma photon pair emitted by positron decay and pulse data sets of other gamma photons;

s2: calculating joint likelihood probability function of multidimensional data sample in each time segment by adopting simulation (such as Monte Carlo simulation)

S3: judging whether the currently received data fragment comes from a positron emission event or not by calculating a combined multi-attribute likelihood function of the multi-dimensional data set of the time period;

s4: counting the output electric pulses, and accumulating all positron emission events according to different event attributes;

s5: establishing a transfer function of the system for each voxel through experiments and simulation, wherein the input of the transfer function is the activity size of the voxel, and the output is a count value marked by each attribute;

s6: and taking the actually measured count values with different attributes as the output of the transfer function, inverting the input of the transfer function, and solving to obtain the activity of each voxel.

Preferably, in the above-mentioned method for imaging of chevrons and gamma events, the reading of the pulse data set of photon information refers to the reading of the time information of each photon by means of photon counting, and the employed photoelectric device is generally a photoelectric device with photon case resolution capability, such as a photomultiplier tube, a silicon photomultiplier tube, an avalanche photodiode, etc., and can acquire pulse data sets of positron emission chevrons and gamma photon pairs emitted by positron decay, as well as other gamma photons.

Preferably, in one of the above-mentioned chev-event and gamma event hybrid imaging methods, the joint multi-attribute likelihood function of the detector is a joint likelihood probability function of multi-dimensional data samples of each detector unit.

Preferably, in one of the above-described methods of Checkov event-gamma event hybrid imaging, two positron emission events of different nature are distinguished by temporal and energy discrimination.

Preferably, in one of the above-mentioned methods of imaging by coincidence of a Cherotkoff event and a gamma event, the Cherotkoff single event is a Cherotkoff effect in a medium caused by a single radioisotope nucleus emitting charged particles.

Preferably, in the above-mentioned method for imaging a koff event and a gamma event, the single photon event is an event that an organism hits an optoelectronic device and is absorbed by a single visible light or soft ultraviolet light photon emitted from a self-luminescence or positron event.

Preferably, in one of the above-described Checkov event and gamma event hybrid imaging methods, the pair of gamma photons is a pair of opposite momentum gamma photons having an energy value of about 511keV that decay from a positron.

Preferably, in the above-mentioned one koff event and gamma event hybrid imaging method, the inversion of the large-scale equation system may be performed by a direct method or an iterative method.

Preferably, in the above-mentioned one koff event and gamma event hybrid imaging method, the position at which the positron event occurs is a position of a nuclide in a living body when the nuclide emits a charged particle, and the relative positions of the nuclide incident on a sensitive aperture of the detector are different from each other.

Preferably, in the above-mentioned cheyne-stokes event and gamma event hybrid imaging method, the reconstruction cheyne-stokes event may adopt an analytical reconstruction method or an iterative reconstruction method.

Preferably, in the above-mentioned method for imaging by matching Cherotkoff events with gamma events, the analytical reconstruction method is represented by Filtered Back-Projection (FBP), i.e. Projection data p (s, θ) is first Filtered by oblique wave to obtain Filtered data q (s, θ), and then the Filtered data is Back-projected to obtain reconstructed image f (x, y), and the relationship between the reconstructed image f (x, y) and the Filtered data is

Preferably, in the above-mentioned method for imaging by matching a chevrolet event and a gamma event, the oblique wave filtering is performed by performing a one-dimensional fourier transform on the projection data P (s, θ) with s as a variable to obtain P (ω, θ), then multiplying P (ω, θ) by a transfer function | ω |, of the ramp filter to obtain Q (ω, θ), and then performing a one-dimensional inverse fourier transform on Q (ω, θ) with ω as a variable to obtain Q (s, θ).

Preferably, in the above-mentioned Cherotkoff event-gamma event coincidence imaging method, the iterative reconstruction method is divided into algebraic iteration and statistical iteration.

Preferably, in the above-mentioned Cherokov event-gamma event coincidence imaging method, a representative method of the algebraic iteration is ART (Algebraic Reconstruction technique) algorithm, and an iterative process formula is

Namely, it is

Preferably, in the above-mentioned Cherokov event and gamma event hybrid imaging method, a representative method of the statistical iteration is an ML-EM (maximum likelihood function by maximum expectation) algorithm, and the iterative formula is

Namely, it is

A Cherotkoff event and gamma event coincidence imaging device comprises

The proton-rich isotope injection module is used for marking substances participating in physiological and biochemical processes in organisms, and the main content of the proton-rich isotope injection module is to shield background light outside the organisms and enable the organisms to be provided with luminous markers; the proton-rich isotope injection module consists of a proton-rich isotope drug delivery module, a labeled compound injection module, a mechanical transmission module and a light sealing module; the proton-rich isotope medicament delivery module is used for stably and automatically delivering the medicament marked with the proton-rich isotope to the organism, and the medicament enters the medicament injection module through the proton-rich isotope medicament delivery module; the labeled compound injection module is used for controlling the dosage of tracer drugs injected into a living organism in real time and consists of a pushing device and a dosage measuring and calculating device; the mechanical transmission module is used for controlling the feeding and the discharging of the living organism inside and outside the detection space and consists of a pushing device and a supporting plate; the light-tight module is used for completely avoiding light from the detection space and eliminating the influence of background noise on the detection result.

The multi-radiation detector module is used for realizing the detection of Cherotkoff photon and gamma photon pairs in a multi-view mode; the multi-radiation detector module consists of a scintillation crystal module, a photoelectric conversion module and a reading electronic module; the scintillation crystal module is used for absorbing gamma photons and Cherotkoff photons, and the photons deposit energy in the scintillation crystal and are converted into visible light photons with wavelengths convenient for detection; the photoelectric conversion module collects the energy of visible light photons through a photocathode, converts the energy into an electric signal, amplifies the signal in a short time through a plurality of dynodes and outputs the signal to the reading electronic module; the reading electronic module is used for pre-amplifying and multiplexing the electric signals output by the photoelectric conversion module and outputting the electric signals to the multi-case time coincidence module.

The multi-case time coincidence module is used for judging whether the multi-photon event belongs to a positron event or not, and the judgment standard is that no less than 5 single-photon events exist in time windows of different detectors; the multi-case time coincidence module consists of a time-to-digital conversion module, an analog-to-digital conversion module, a high-speed transmission module and a photon event attribute packaging module; the time-to-digital conversion module carries out voltage-to-time sampling on the output electric signal by setting a plurality of voltage thresholds, and accurately extracts the time information of the signal by utilizing a plurality of sampling points; the analog-digital conversion module converts the output analog electric signal into a digital signal, which is beneficial to resisting various interferences during high-speed transmission and extracting position information; the high-speed transmission module transmits the processed signals to a field programmable gate array circuit for calculation; and the photon event attribute packaging module is used for respectively packaging the attributes of the gamma event and the Cherotkoff event, and the packaged contents comprise the rising time of the front edge of the electric pulse and the photon energy.

The system transfer function acquisition module is used for acquiring a transfer function of a system, and generally can adopt an experimental and simulation acquisition mode, wherein the simulation acquisition mode adopts mathematical simulation or Monte Carlo simulation; the system transfer function acquisition module consists of a material setting module, a prosthesis setting module and a data inversion module; the material setting module sets simulated material parameters according to actual detection materials; the prosthesis setting module is used for setting a prosthesis with a certain specification to simulate the distribution of proton-rich isotopes in a living organism; and the data inversion module performs inversion calculation on the data obtained by simulation to obtain a system transfer function, and outputs the system transfer function to the nuclide distribution image reconstruction module.

The nuclide distribution image reconstruction module is used for reconstructing the positron event set with the attributes into radioactivity distribution at a certain moment; the nuclide distribution image reconstruction module consists of a data rearrangement and correction module, a data preprocessing module and a position information recovery module; the data rearrangement and correction module extracts time and energy information to correct error data, rearranges the format of the corrected data and converts the data into a format which can be directly read; the data preprocessing module directly reads data and removes obvious noise and interference through a filtering algorithm; and the position information recovery module analyzes or iteratively reconstructs the data according to the preprocessed data, and recovers the positions of the gamma event and the Cherotkoff event in the living organism.

A chev-event and gamma-event coincidence imaging device, wherein: the visible light photon detector and the gamma photon detector both adopt fast time response type photoelectric conversion devices, such as a Hamamatsu photomultiplier tube R9800, a photomultiplier tube R2248 and the like.

According to the above technical scheme, through adopting the utility model discloses a conjunction koff event accords with imaging device with gamma event, can effectively improve the formation of image SNR of device, resists biological tissue self-luminous influence, is particularly suitable for living body formation of images such as positron isotope labeled clinical or toy.

Compared with the prior art, the beneficial effects of the utility model are that:

(1) the method and the device have ultrahigh sensitivity, and have higher system accuracy and imaging quantitative accuracy because more particle information can be explored;

(2) the detector adopts an annular design, can receive photon multi-view full-3D detector design at any angle, and can simultaneously acquire Cherotkoff photon information at innumerable views by one-time scanning;

(3) the time for resisting the self-luminous events of the background light and the organism accords with the design, thereby being beneficial to reducing the background noise of imaging and rejecting the interference of irrelevant events;

(4) the full-event reading design can comprehensively read the multi-dimensional information rich in positron events: angle (2-D), time (1-D), position (3-D), energy (1-D). In particular, the electrical signal of the optoelectronic device is recorded in the form of an event.

Drawings

Fig. 1 is a flowchart of a method for imaging by matching koff events with gamma events according to the present invention.

Fig. 2 is a device structure diagram of the imaging device according to the present invention.

Fig. 3 is a schematic diagram of a photon path corresponding to a chev event and a gamma event according to the present invention.

Figure 4 is a schematic diagram of a typical 3-fold single photon event coincidence in accordance with the present invention.

Fig. 5 is a schematic diagram of the system operating principle of the present invention.

Fig. 6 shows a typical detector unit of a chev event and gamma event coincidence imaging device according to the present invention.

Fig. 7 is a cross-sectional view of the image quality testing prosthesis of the present invention.

Fig. 8 is a cross-sectional view of the reconstruction result of the gamma photon pair event for the image quality testing prosthesis of the present invention.

Fig. 9 is a cross-sectional view of a reconstruction result of the image quality testing prosthesis according to the present invention with the chechoff photon beam.

Fig. 10 is a cross-sectional view of the reconstruction result of the image quality testing prosthesis according to the present invention using two types of photon information.

Reference numerals: the system comprises a proton-rich isotope injection module 100, a proton-rich isotope drug delivery module 110, a labeled compound injection module 120, a mechanical transmission module 130, a light confinement module 140, a multi-radiation detector module 200, a scintillation crystal module 210, a photoelectric conversion module 220, a readout electronics module 230, a multiple-event time coincidence module 300, a time-to-digital conversion module 310, an analog-to-digital conversion module 320, a high-speed transmission module 330, a photon event attribute encapsulation module 340, a system transfer function acquisition module 400, a material setting module 410, a prosthesis setting module 420, a data inversion module 430, a nuclide distribution image reconstruction module 500, a data rearrangement and correction module 510, a data preprocessing module 520 and a position information recovery module 530.

Detailed Description

The utility model discloses a chev-conk event accords with image device with gamma event, and this method and device can realize the mark of event arrival time effectively, promote the time resolution of module and device.

The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

As shown in fig. 1, the utility model discloses a cheuchov's event and gamma event coincidence imaging method is through the data form collection single photon signal with the event, recycles the position that time coincidence and estimation theory screened out the positron event, and specific method step is:

s1: arranging a visible light photon detector and a gamma photon detector to obtain two different event attributes of a pulse data set of positron emission Cherotkoff effect photons, a gamma photon pair emitted by positron decay and pulse data sets of other gamma photons;

s2: calculating joint likelihood probability function of multidimensional data sample in each time segment by adopting simulation (such as Monte Carlo simulation)

S3: judging whether the currently received data fragment comes from a positron emission event or not by calculating a combined multi-attribute likelihood function of the multi-dimensional data set of the time period;

s4: counting the output electric pulses, and accumulating all positron emission events according to different event attributes;

s5: establishing a transfer function of the system for each voxel through experiments and simulation, wherein the input of the transfer function is the activity size of the voxel, and the output is a count value marked by each attribute;

s6: and taking the actually measured count values with different attributes as the output of the transfer function, inverting the input of the transfer function, and solving to obtain the activity of each voxel.

In the above conjunction koff event and gamma event coincidence imaging device, the reading of the photon information pulse data set refers to reading of time information of each photon by a photon counting method, and the adopted photoelectric device generally has a photon case resolution capability, such as a photomultiplier tube, a silicon photomultiplier tube, an avalanche photodiode, and the like, and can obtain pulse data sets of positron emission koff effect photons, gamma photon pairs emitted by positron decay, and other gamma photons.

In the above one kind of conjunction koff event and gamma event coincidence imaging device, the joint multi-attribute likelihood function of the detector is a joint likelihood probability function of multi-dimensional data samples of each detector unit.

In the above conjunction koff event and gamma event coincidence imaging device, two positron emission events with different attributes are distinguished by adopting a time and energy discrimination mode.

In the above one kind of conjunction koff event and gamma event coincidence imaging device, the conjunction koff single event refers to the fact that a single radioisotope nucleus emits charged particles to generate the conjunction koff effect in a medium.

In the above congou event and gamma event coincidence imaging device, the single photon event refers to an event that an organism hits a photoelectric device and is absorbed through a single visible light or soft ultraviolet light photon emitted by a self-luminescence or positron event.

In the above imaging device for coincidence of a Cherotkoff event and a gamma event, the gamma photon pair is a Cherotkoff event and a gamma event which are more than positrons, and the inversion of the large-scale equation set can be performed by a direct method or an iterative method.

In the above conjunction koff event and gamma event coincidence imaging device, the position where the positron event occurs refers to the position of the nuclide in the living body when the nuclide emits charged particles, and the relative positions of the sensitive holes of the detector incident at different positions are different.

In the above imaging device, the reconstruction of the Cherotkoff event may adopt either an analytic reconstruction method or an iterative reconstruction method.

In the above imaging apparatus integrating koff event and gamma event, a representative method of the analytic reconstruction method is a Filtered Back-Projection (FBP), that is, Projection data p (s, θ) is first subjected to oblique wave filtering to obtain Filtered data q (s, θ), and then subjected to Back Projection to obtain a reconstructed image f (x, y), where a relationship between the reconstructed image f (x, y) and the Filtered data is a reconstructed image f (x, y)

In the above-mentioned conjunction koff event and gamma event coincidence imaging apparatus, the ramp filtering is to perform one-dimensional fourier transform on the projection data P (s, θ) with s as a variable to obtain P (ω, θ), then multiply P (ω, θ) by a transfer function | ω |, of a ramp filter to obtain Q (ω, θ), and then perform one-dimensional inverse fourier transform on Q (ω, θ) with ω as a variable to obtain Q (s, θ).

In the above imaging device for coincidence of the Cherov event and the gamma event, the iterative reconstruction method is divided into algebraic iteration and statistical iteration.

In the above conjunction koff event and gamma event coincidence imaging device, a typical method of the algebraic iteration is an art (algebra Reconstruction technique) algorithm, and an iteration process formula of the algebra iteration algorithm is

Namely, it is

In the above one kind of conjunction koff event and gamma event coincidence imaging device, the representative method of the statistical iteration is an ML-EM (maximum likelihood function is obtained by obtaining a maximum expectation value) algorithm, and the iteration formula is

Namely, it is

As shown in fig. 2, the present invention discloses a conjunction koff event and gamma event coincidence imaging device, which comprises a proton-rich isotope injection module 100, a multi-radiation detector module 200, a multi-event time coincidence module 300, a system transfer function acquisition module 400 and a nuclide distribution image reconstruction module 500, wherein,

the proton-rich isotope injection module 100 is used for labeling substances participating in physiological and biochemical processes in a living body, mainly shields background light outside the living body, and enables the living body to be provided with a label capable of emitting light, and the proton-rich isotope injection module 100 is composed of a proton-rich isotope drug delivery module 110, a labeled compound injection module 120, a mechanical transmission module 130 and a light sealing module 140: the proton-rich isotope drug delivery module 110 is used for stably and automatically delivering the drug marked with the proton-rich isotope to the organism, and the drug enters the drug injection module 120 through the proton-rich isotope drug delivery module 110; the labeled compound injection module 120 is used for controlling the dosage of the tracer medicament injected into a living organism in real time and comprises a pushing device and a dosage measuring and calculating device; the mechanical transmission module 130 is used for controlling the sending in and out of the living organism in the detection space and is composed of a pushing device and a supporting plate; the light sealing module 140 is used for completely avoiding light from the detection space and eliminating the influence of background noise on the detection result;

a multi-radiation detector module 200 for detecting cheyne-koff photon and gamma photon pairs in a multi-view manner, the multi-radiation detector module 200 being composed of a scintillation crystal module 210, a photoelectric conversion module 220 and a readout electronics module 230: the scintillation crystal module 210 is configured to absorb gamma photons and Cherotkoff photons, where the photons deposit energy in the scintillation crystal and are converted into visible light photons with wavelengths convenient for detection; the photoelectric conversion module 220 collects the energy of the visible light photons through the photocathode, converts the energy into an electrical signal, amplifies the signal in a short time through a plurality of dynodes, and outputs the signal to the readout electronics module 230; the readout electronics module 230 is configured to perform pre-amplification and multiplexing on the electrical signal output by the photoelectric conversion module, and output the electrical signal to the multiple-instance time compliance module 300;

the multiple-instance time coincidence module 300 is used for judging whether a multi-photon event belongs to a positron event, the judgment standard is that no less than 5 single photon events exist in time windows of different detectors, and the multiple-instance time coincidence module 300 is composed of a time-to-digital conversion module 310, an analog-to-digital conversion module 320, a high-speed transmission module 330 and a photon event attribute encapsulation module 340: the time-to-digital conversion module 310 performs voltage-to-time sampling on the output electrical signal by setting a plurality of voltage thresholds, and accurately extracts time information of the signal by using a plurality of sampling points; the analog-digital conversion module 320 converts the output analog electric signal into a digital signal, which is beneficial to resisting various interferences during high-speed transmission and extracting position information; the high-speed transmission module 330 transmits the processed signals to the field programmable gate array circuit for calculation; the photon event attribute encapsulation module 340 encapsulates the attributes of the gamma event and the Cherotkoff event respectively, and the encapsulated content comprises the rising time of the leading edge of the electric pulse and the photon energy;

the system transfer function obtaining module 400 is configured to obtain a transfer function of a system, and may generally adopt an experimental and simulation obtaining manner, where the simulation obtaining manner adopts mathematical simulation or monte carlo simulation, and the system transfer function obtaining module 400 is configured by a material setting module 410, a prosthesis setting module 420, and a data inversion module 430: the material setting module 410 sets simulated material parameters according to actual detected materials; the prosthesis setting module 420 sets a prosthesis of a certain specification to simulate the distribution of proton-rich isotopes in a living organism; the data inversion module 430 performs inversion calculation on the simulated data to obtain a system transfer function, and outputs the system transfer function to the nuclide distribution image reconstruction module 500;

a nuclide distribution image reconstruction module 500 for reconstructing a positron event set with attributes into a radioactivity distribution at a certain time, the nuclide distribution image reconstruction module 500 comprising a data rearrangement and correction module 510, a data preprocessing module 520, and a location information recovery module 530: the data rearrangement and correction module 510 extracts time and energy information to correct error data, rearranges the format of the corrected data, and converts the data into a format that can be directly read; the data preprocessing module 520 directly reads data and removes obvious noise and interference through a filtering algorithm; the location information recovery module 530 performs analysis or iterative reconstruction according to the preprocessed data, and recovers locations of the gamma event and the cheuchov event occurring in the living organism.

A chev-event and gamma-event coincidence imaging device, wherein: the visible light photon detector and the gamma photon detector both adopt fast time response type photoelectric conversion devices, such as a Hamamatsu photomultiplier tube R9800, a photomultiplier tube R2248 and the like.

The cheuchov event and gamma event coincidence imaging apparatus and method of the present invention are further described by several specific embodiments. The utility model provides a cheuchov incident accords with image device and method with gamma incident, and parameter, wave filter design, the time that it involves accord with the processing needs and adjust in order to reach good cheuchov radiation resolution performance and shorter pulse duration according to the characteristics with acquireing data. The parameters of the application embodiments involved in processing the data are listed here.

Example 1:

the parameters of the data processed in this example are listed here:

the actual apparatus used in step (1) was a dark box of 1.5 m.times.1.5 m. The source is a 511keV positron annihilation gamma photon 18F-FDG. Adopting a scintillation detector of lutetium yttrium silicate/photomultiplier/bluish violet silicon photomultiplier as a gamma photon detection element, wherein the combination of the detector units adopts an annular structure as shown in figure 7;

step (2) adopting 7-dimensional information including angle (2-D), time (1-D), position (3-D) and energy (1-D) of the positron event as an attribute value to establish a double-particle likelihood function;

step (3), the coincidence time is about 2ns, off-line time coincidence processing is adopted for coincidence judgment, and particle counting is gated;

rearranging the count value into a projection value of the sinogram in a histogram restoration mode;

step 5, acquiring a system transfer function by adopting an MATLAB mathematical simulation mode;

and (6) directly drawing the activity distribution of the positrons by adopting an analytic nuclide distribution reconstruction method.

Example 2:

the parameters of the data processed by the present application example 2 are listed here:

the actual device used in step (1) is a dark box with dimensions of 0.15 m.times.0.15 m. The source is a 511keV positron annihilation gamma photon 18F-FDG. The method comprises the following steps of (1) adopting a red light enhanced silicon photomultiplier as a photosensitive element for Cherokoff photon detection, adopting a scintillation detector of a lanthanum bromide/blue-violet light silicon photomultiplier as a gamma photon detection element, and adopting a 12-plate structure in combination of detector units;

step (2) adopting 7-dimensional information including angle (2-D), time (1-D), position (3-D) and energy (1-D) of the positron event as an attribute value to establish a double-particle likelihood function;

step (3), the coincidence time is about 2ns, off-line time coincidence processing is adopted for coincidence judgment, and particle counting is gated;

step (4) adopts a mode of list data, and the projection data does not need to be rearranged;

step 5, acquiring a system transfer function in an experimental measurement mode;

and (6) directly drawing the activity distribution of the positrons by adopting an iterative nuclide distribution reconstruction method, so that the maximum posterior criterion is met.

The utility model provides an among the image method is accorded with gamma event to the cheuchov event. And eliminating spontaneous light and background light of the organism through time coincidence. The time and the position of the positron event are judged according to the relative position of the single photon event in the hole, and compared with the Cherotkoff imaging method for reading out single visual angle or current charge in the background technology, the imaging quality is good, and more Cherotkoff photons are captured.

In the Cherotkoff event and gamma event coincidence imaging method disclosed in the utility model, the injected isotopes capable of emitting charged particles can be used for marking biochemical and physiological processes in organisms; reading the photon count of the charged particles emitting the Checkov photons to the detector module and the time of each count; performing time coincidence on the read time; estimating the location of the positron event by the relative position of the photons within the bore; and reconstructing the position and time of the estimated Cherotkoff event to obtain the distribution of the nuclide.

Through adopting the utility model discloses a cheuchov's event accords with imaging device with gamma event, can effectively improve the formation of image SNR of device, resists biological tissue self-luminous influence, is particularly suitable for the not high live body formation of image of degree of depth requirements such as toy.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (2)

1. A chev-event and gamma event coincidence imaging device, comprising:

the nuclear species distribution image reconstruction system comprises a proton-rich isotope injection module (100), a multi-radiation detector module (200), a multi-event time coincidence module (300), a system transfer function acquisition module (400) and a nuclear species distribution image reconstruction module (500), wherein the proton-rich isotope injection module (100) is fixedly connected with the multi-radiation detector module (200) in a coupling manner, the multi-event time coincidence module (300) is connected with the multi-radiation detector module (200) through a communication line, and the system transfer function acquisition module (400) is respectively electrically connected with the multi-event time coincidence module (300) and the nuclear species distribution image reconstruction module (500) through signal lines; the proton-rich isotope injection module (100) is composed of a proton-rich isotope drug delivery module (110), a labeled compound injection module (120), a mechanical transmission module (130) and an optical sealing module (140), the labeled compound injection module (120) is arranged in the proton-rich isotope drug delivery module (110), and the labeled compound injection module (120) is composed of a pushing device and a dose measuring and calculating device; the labeled compound injection module (120) is fixedly connected with the mechanical transmission module (130), the mechanical transmission module (130) is composed of a pushing device and a supporting plate, and the proton-rich isotope injection module (100) is internally provided with a light sealing module (140); the multi-radiation detector module (200) is composed of a scintillation crystal module (210), a photoelectric conversion module (220) and a reading electronic module (230), wherein the scintillation crystal module (210) is electrically connected with the photoelectric conversion module (220), and a signal output end of the photoelectric conversion module (220) is electrically connected with a signal input end of the reading electronic module (230) through a signal line; the multiple-case time coincidence module (300) is composed of a time-to-digital conversion module (310), an analog-to-digital conversion module (320), a high-speed transmission module (330) and a photon event attribute packaging module (340), wherein the time-to-digital conversion module (310) is fixedly arranged inside the multiple-case time coincidence module (300), a signal output end of the time-to-digital conversion module (310) is electrically connected with a signal input end of the analog-to-digital conversion module (320), a signal output end of the analog-to-digital conversion module (320) is electrically connected with the high-speed transmission module (330), and the photon event attribute packaging module (340) is fixedly arranged inside the multiple-case time coincidence module (300).

2. A chev-event and gamma-event coincidence imaging device according to claim 1, characterized in that: the visible light photon detector and the gamma photon detector both adopt a quick time response type photoelectric conversion device.

Images