CN107874773B

CN107874773B - Photon detection method, device, equipment and system and storage medium

Info

Publication number: CN107874773B
Application number: CN201710975365.XA
Authority: CN
Inventors: 谢思维; 杨静梧; 黄秋; 龚政; 应高阳; 苏志宏
Original assignee: Zhongpai S&t Shenzhen Co ltd
Current assignee: Zhongpai S&t Shenzhen Co ltd
Priority date: 2017-10-16
Filing date: 2017-10-16
Publication date: 2020-12-08
Anticipated expiration: 2037-10-16
Also published as: CN107874773A; WO2019076268A1

Abstract

The invention provides a photon detection method, a photon detection device, photon detection equipment, photon detection system and a storage medium. The method comprises the following steps: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining the reaction projection position of the high-energy photon based on the energy distribution rule of the first number of energy signals and the second number of energy signals. The method is based on the electric signals output by the sensor read by the shared reading circuit and the independent reading circuit which are arranged on the basis of the propagation characteristic and the distribution characteristic of the scintillation photons, so that the channel reduction is realized.

Description

Photon detection method, device, equipment and system and storage medium

Technical Field

The present invention relates to the field of positron emission imaging, and in particular, to a photon detection method, apparatus, device, system, and storage medium.

Background

In recent years, the positron emission tomography (pet) era has gradually shifted to the Silicon Photomultiplier (SiPM) era. Positron Emission Tomography (PET) is a technology for displaying the internal structure of a human or animal body by using a radionuclide tracing method, and is a main means for nuclear medicine research and clinical diagnosis.

SiPM size is less, and detection efficiency is high to make detector compact structure, system sensitivity is high. However, just because of the small size of the sipms, the number of sipms coupled by a scintillation crystal of the same cross-sectional area is much greater than that of a PMT. Taking a single ring whole body PET system with an aperture of 76cm as an example, the light-emitting area of the scintillation crystal is about 125cm²196 Hamamatsu R9800 PMTs (light sensitive area of 25mm) need to be coupled, or 3400 SiPMs with size of 6 mm. If the signals of all sipms are read out separately, the number of system channels will increase by about 17 times. Therefore, the technological innovation of PMT systems into SiPM systems presents certain challenges for the signal readout circuitry in PET systems.

Accordingly, there is a need to provide an electronic channel reduction technique that at least partially solves the above-mentioned problems in the prior art.

Disclosure of Invention

To at least partially solve the problems in the prior art, the present invention provides a photon detection method, apparatus, device, system, and storage medium.

According to an aspect of the present invention, there is provided a photon detection method, comprising: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining a reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

Illustratively, the photon detection method further comprises: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals.

Exemplary, determining the reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals comprises: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

Illustratively, the photon detection method further comprises: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

Illustratively, the first number is no less than the number of sensors that are encompassed by a maximum radiation range of scintillation photons in the sensor array that are generated by the reaction of the high-energy photons with the scintillation crystal.

Illustratively, co-ordinated sensors in different sensor areas share the same shared readout circuitry.

Illustratively, the second number is not less than N-1, where N is the number of at least two sensor regions.

According to another aspect of the present invention, there is provided a photon detection apparatus comprising: the sensor array is coupled with the scintillation crystal and used for detecting scintillation photons generated by the reaction of the high-energy photons and the scintillation crystal, wherein the sensor array is averagely divided into at least two sensor areas; a readout circuit connected to the sensor array for receiving the electrical signals output by the sensor array and outputting an energy signal related to the energy of the high-energy photons, wherein the readout circuit comprises a first number of shared readout circuits and a second number of individual readout circuits, the first number being equal to the number of sensors in each sensor region, and the first number of shared readout circuits connecting all the sensors in each sensor region in a one-to-one correspondence, each individual readout circuit connecting a single sensor in the sensor array; and the processing circuit is used for receiving the first number of energy signals respectively output by the first number of shared reading circuits and the second number of energy signals respectively output by the second number of independent reading circuits, and determining the reaction projection position of the high-energy photon based on the energy distribution rule of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is the projection of the reaction position of the high-energy photon in the scintillation crystal on the sensor array.

Illustratively, the processing circuit is further configured to determine an energy and/or arrival time of the high-energy photon based on the first number of energy signals.

According to another aspect of the present invention, there is provided a photon detection apparatus comprising: the receiving module is used for receiving a first number of energy signals respectively output by a first number of shared reading circuits connected with the sensor array and a second number of energy signals respectively output by a second number of independent reading circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared reading circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent reading circuit is connected with a single sensor in the sensor array; and the position determining module is used for determining the reaction projection position of the high-energy photon based on the energy distribution rule of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is the projection of the reaction position of the high-energy photon in the scintillation crystal coupled with the sensor array on the sensor array.

Illustratively, the photon detection apparatus further comprises: an energy or time determination module for determining the energy and/or arrival time of the high-energy photons based on the first number of energy signals.

Illustratively, the location determination module includes: and the input submodule is used for inputting the first number of energy signals and the second number of energy signals into the machine learning model for analysis so as to obtain position data which is output by the machine learning model and is about the reaction projection positions of the high-energy photons.

Illustratively, the photon detection apparatus further comprises: a simulation module for performing photon reaction event simulation at a sample reaction location to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction location, wherein a sample projection location corresponding to the sample reaction location is known; and the training module is used for taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model, taking the position data about the projection positions of the samples as the target output of the machine learning model, and training the machine learning model.

According to another aspect of the present invention, there is provided a photon detection system comprising a processor and a memory, wherein the memory has stored therein computer program instructions for execution by the processor to perform the steps of: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining a reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

Illustratively, the computer program instructions when executed by the processor are further for performing the steps of: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals.

Illustratively, the step of determining the reactive projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, the computer program instructions being executable by the processor for determining the reactive projection position of the high-energy photon comprises: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

Illustratively, the computer program instructions when executed by the processor are further for performing the steps of: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

According to another aspect of the present invention, there is provided a storage medium having stored thereon program instructions operable when executed to perform the steps of: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining a reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

Illustratively, the program instructions are further operable when executed to perform the steps of: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals.

For example, the step of determining the reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, which the program instructions are configured to execute when running, comprises: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

Illustratively, the program instructions are further operable when executed to perform the steps of: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

According to the photon detection method, the device, the equipment and the system as well as the storage medium, the electric signals output by the sensor are read by the shared reading circuit and the independent reading circuit which are arranged based on the propagation characteristic and the distribution characteristic of the scintillation photons, so that the aim of reducing the channel can be achieved without influencing the detector, and the power consumption and the cost of a PET system can be effectively reduced.

In this summary, a number of simplified concepts are introduced that are further described in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The advantages and features of the present invention are described in detail below with reference to the accompanying drawings.

Drawings

The following drawings of the invention are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, there is shown in the drawings,

FIG. 1 shows a schematic view of a scintillation photon radiation zone according to an example of the invention;

FIG. 2 shows a schematic diagram of total reflection of scintillation photons in accordance with an example of the present invention;

FIG. 3 shows a distribution plot of scintillation photons in a SiPM array produced by a single photon reaction event simulated using optical software, according to one embodiment of the present invention;

FIG. 4 shows a schematic flow diagram of a photon detection method according to one embodiment of the invention;

FIG. 5 shows a schematic diagram of sensor area division and individual readout circuit arrangement according to one embodiment of the present invention;

FIG. 6 illustrates a schematic view of a readout sequence of electrical signals of the sensor array shown in FIG. 5, according to one embodiment of the present invention;

7a-7d are schematic diagrams illustrating, respectively, the energy signal output by the shared readout circuit when the reaction site of a gamma photon is four different sites, according to an embodiment of the present invention;

FIG. 8a shows a schematic diagram of sensor area division and individual readout circuitry arrangement according to another embodiment of the present invention;

FIG. 8b shows a schematic diagram of sensor area division and individual readout circuitry arrangement according to another embodiment of the present invention;

FIG. 9 shows a schematic block diagram of a photon detection apparatus according to one embodiment of the present invention;

FIG. 10 shows a schematic block diagram of a photon detection apparatus according to one embodiment of the present invention; and

FIG. 11 shows a schematic block diagram of a photon detection system in accordance with one embodiment of the present invention.

Detailed Description

In the following description, numerous details are provided to provide a thorough understanding of the present invention. One skilled in the art will recognize, however, that the following description is merely illustrative of a preferred embodiment of the invention and that the invention may be practiced without one or more of these specific details. In addition, some technical features that are well known in the art are not described in order to avoid confusion with the present invention.

In order to solve the above problems, the present invention provides a photon detection method, apparatus, device, system and storage medium. According to the embodiment of the invention, the sensor array is divided into different areas, and some shared readout circuits are shared among the different areas, so as to reduce the number of channels (each readout circuit can be regarded as one readout channel, and the number of channels is reduced, namely the number of constructed readout circuits is reduced). In addition, in order to assist in identifying which sensors the energy signal output by the shared readout circuit originates from, the individual readout circuit is used to individually read out the signals of certain sensors as the identification mark. Compared with the channel reduction technology for reading out the electric signals output by the sensors in the whole row or the whole column by the same reading circuit, the channel reduction technology provided by the invention takes the propagation and distribution conditions of scintillation photons (or called visible photons) in the sensor array into consideration, so that the pertinence to a photosensitive area is stronger, and the situation that the performance of a detector cannot be fully exerted due to the limitation of an electronic system is avoided. The theoretical basis for the channel reduction techniques provided herein is described in detail below.

The description is given herein taking high energy photons as the gamma photons. Gamma photons are generated by the positron annihilation effect occurring within the body of the object to be imaged. In particular, when scanning an object to be imaged with a positron emission imaging apparatus, a tracer containing a radioisotope may be injected into the object to be imaged. Annihilation occurs when the positron emitted by an isotope encounters a negative electron in the body of the subject being imaged, thereby producing a pair of gamma photons of opposite direction (180 degrees apart) and 511KeV energy. The resulting pair of oppositely directed gamma photons are incident in two opposite locations in the scintillation crystal, respectively. The gamma photons enter the scintillation crystal to interact with outer electrons of atoms, the outer electrons are changed into an excited state after absorbing the energy of the gamma photons, and the electrons in the excited state are subjected to energy level transition to generate a large number of scintillation photons. A sensor array coupled to the scintillation crystal can detect these scintillation photons and, when it detects a scintillation photon, can convert the optical signal of the scintillation photon into an electrical signal and output the electrical signal obtained by the conversion.

Fig. 1 shows a schematic view of a scintillation photon radiation zone according to an example of the invention. In the case of a scintillation crystal that is a discrete crystal, as shown in fig. 1, scintillation photons produced by a single photon reaction event are transmitted from a single small crystal into a light guide and subsequently incident on a fractional region of the SiPM array. It is noted that a photon-responsive event as described herein refers to an event in which a high-energy photon reacts with the scintillation crystal. Due to the thin thickness of the light guide layer (typically less than 5mm) scintillation photons are not fully dispersed in the light guide and are absorbed by the SiPM. Thus, the radiation area of the scintillation photons is constant in the event of a primary photon reaction, the thinner the photoconductive layer, the smaller the radiation area of the scintillation photons.

In the case of a scintillation crystal that is a continuous crystal, six faces of the crystal are polished, and five faces, except the face that couples the SiPM array, are affixed with highly reflective films. For example, if the scintillation crystal is a yttrium lutetium silicate scintillation crystal (LYSO), its refractive index is 1.82. The surface of the SiPM is glass and its refractive index is 1.5. Therefore, the scintillation photons travel from the scintillation crystal to the SiPM from the optically dense medium to the optically sparse medium, and as shown in fig. 2, a total reflection phenomenon occurs. Fig. 2 shows a schematic diagram of the total reflection of scintillation photons according to an example of the invention. It is understood that scintillation photons incident on the SiPM at angles of incidence greater than the critical angle will be reflected and thus not incident on the SiPM. That is, most of the scintillation photons will be received by sipms in a certain area, and only a very small fraction of the scintillation photons will be received by sipms outside this area after diffuse reflection. Therefore, whether the scintillation crystal is a continuous crystal or a discrete crystal, only a portion of the sipms in the SiPM array can receive a light signal in a single photon reaction event.

The invention is described in detail below with the example of a continuous crystal coupling of 10 x 10 arrays of sipms (each size of 6mm) of dimensions 60mm x 20 mm. Optical software can be used to simulate photon reaction events and track the trajectory of all scintillation photons until they are absorbed. Fig. 3 shows a distribution plot of scintillation photons in an SiPM array produced by a single photon reaction event simulated using optical software, according to one embodiment of the present invention. In fig. 3, two coordinates in the horizontal direction indicate the number of sipms, and a coordinate in the vertical direction indicates the number of scintillation photons received by the sipms. As can be seen from fig. 3, only a partial area of sipms can receive scintillation photons in a photon reaction event, where the sipms whose reaction positions (i.e., where gamma photons react in the scintillation crystal) project on the SiPM array (i.e., reaction projection positions) have the largest number of collected scintillation photons, the highest energy of the detected light signal, and the farther away from the reaction projection positions the lower energy of the detected light signal. It is understood that when the reaction position of the gamma photon moves along the horizontal direction, the distribution area of the scintillation photon in the SiPM array also moves along the horizontal direction by the same distance, and the distribution form of the scintillation photon is basically unchanged. Thus, it is not necessary to assign one readout circuit to all sensors, but a shared readout circuit can be provided according to the distribution of scintillation photons in the SiPM array.

From the above analysis, it is possible to find a channel reduction technique in which the same readout circuitry is shared with sensor regions of the same size as the radiation range of the scintillation photons to achieve a reduction in the number of channels.

FIG. 4 shows a schematic flow diagram of a photon detection method 400 according to one embodiment of the invention. As shown in fig. 4, the photon detection method 400 includes the following steps.

In step S410, a first number of energy signals respectively output by a first number of shared readout circuits connected to the sensor array and a second number of energy signals respectively output by a second number of individual readout circuits are received, wherein the sensor array is averagely divided into at least two sensor regions, the first number is equal to the number of sensors in each sensor region, and the first number of shared readout circuits connect all the sensors in each sensor region in a one-to-one correspondence, and each individual readout circuit connects a single sensor in the sensor array.

In step S420, a reaction projection position of the high-energy photon is determined based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in the scintillation crystal coupled with the sensor array on the sensor array.

The photon detection method 400 is described below along the example shown in FIG. 3, which takes as an example a 10 × 10 array of SiPMs (each SiPM size is 6mm) coupled by a continuous crystal having dimensions 60mm × 60mm × 20 mm. Centered on the reaction site of the gamma photon, the scintillation photon is assumed to travel a distance in the continuous crystal or light guide that does not exceed the distance of 2.5 sensor edge lengths in the sensor array. That is, no more than 25 sipms receive the optical signal in a single photon reaction event. In this case, the sensor area may be divided and channel reduced in the manner shown in fig. 5.

FIG. 5 shows a schematic diagram of sensor area division and individual readout circuitry arrangement according to one embodiment of the present invention. As shown in fig. 5, the 100 sensors may be divided into A, B, C, D four zones along the centerline, each zone including 25 sensors. In each zone, the sensors are numbered from left to right, top to bottom, in order 1.1, 1.2, 1.3 … 5.5.5.

For each sensor region, a first number of shared readout circuits are connected in a one-to-one correspondence with all sensors therein, such that different sensor regions can share the first number of shared readout circuits. Illustratively, co-ordinated sensors in different sensor areas share the same shared readout circuitry, which facilitates later identification of the sensor that detected the scintillation photon. Of course, sensors with non-uniform coordinates in different sensor areas may also share the same shared readout circuit, which may be set as desired. The coordinates of a sensor as described herein are the location of the sensor in the area of the sensor where it is located. In the case where the sensors are numbered as shown in fig. 5, the coordinates of the sensors may be represented by the numbers of the sensors, and the coordinates are the same as the reference numbers.

In the example shown in fig. 5, the sensors (m, n) of the A, B, C, D four regions share one readout circuit (m ═ 1,2,3,4, 5; n ═ 1,2,3,4,5), for a total of 25 readout channels. It will be appreciated that if only 25 shared readout circuits were provided, in some cases, for example when the reaction site of a gamma photon was above the sensor numbered 3.3 in A, B, C, D four regions respectively, the energy signals output by the 25 shared readout circuits would be the same or substantially the same, and it would not be possible to distinguish in which region the reaction site was above the sensor numbered 3.3. Therefore, it is necessary to provide some individual readout circuits for assisting identification, for example, 8 individual readout circuits in the example shown in fig. 5. As shown in fig. 5, the electrical signals of the sensors numbered 2.2 and 4.4 in the area A, D and 2.4 and 4.2 in the area B, C (i.e., the sensors in the smaller dark square frame circle in fig. 5) can be read out individually for 8 readout channels.

FIG. 6 illustrates a schematic view of a readout sequence of electrical signals of the sensor array shown in FIG. 5, according to one embodiment of the present invention. The electrical signals of the 33 channels can be read out sequentially in the manner shown in fig. 6. As described above, the sensor functions to photoelectrically convert the optical signal of the scintillation photon, and thus the sensor outputs an electrical signal obtained after photoelectric conversion. The readout circuit is used for processing the electric signal from the sensor and outputting an energy signal representing the energy of the optical signal received by the sensor. It will be appreciated that the amount of energy represented by the energy signal output by each readout circuit is positively correlated to the number of scintillation photons received by the sensor outputting the electrical signal to that readout circuit.

A photon reaction event occurs and the readout circuit can output energy signals of 33 channels. In one example, the energy signals of 33 channels may be used as inputs to a machine learning model, which may output the reaction projection locations of the gamma photons. The machine learning model can decode the reaction projection positions of gamma photons according to the signal characteristics of the energy signals output by the first 8 individual readout channels (a2.2, a4.4, B2.4, B4.2, C2.4, C4.2, D2.2, and D4.4) and the last 25 shared readout channels.

As described above, the closer to the reaction projection location of the gamma photon, the higher the energy of the optical signal detected by the SiPM. Assume that the energy of the optical signal detected by the sipms at the reaction projection position is E3, the energy of the optical signal detected by the adjacent 8 sipms is E2, and the energy of the optical signal detected by the outermost 16 sipms is E1. When the separate readout channels a2.2 and a4.4 have signals, four situations like fig. 7a-7d occur. Fig. 7a-7d show schematic diagrams of energy signals output by a shared readout circuit when the reaction site of a gamma photon is four different sites, respectively, according to an embodiment of the invention. When the situation as shown in fig. 7a occurs, the signals of the 33 channels are in turn: e2, E2, 0, E1, E1, E1, E1, E1, E1, E2, E2, E2, E1, E1, E2, E3, E2, E1, E1, E2, E2, E2, E1, E1, E1, E1, E1, E1. Only the 1 st and the 2 nd of the first 8 independent reading channels have energy signals, the strength of the energy signals in the last 25 shared reading channels are arranged according to a certain rule, and the energy signals in the shared reading channels all come from the area A. When the three cases as shown in 7b, 7c and 7d occur, only the 1 st and 2 nd energetic signals remain in the first 8 individual read channels, and the arrangement of the energies in the last 25 shared read channels differs. Note that in the case shown in fig. 7B, the energy signals in the 25 shared readout channels are four columns (20) from region a and one column (5) from region B. Fig. 7c is similar to fig. 7d, with the energy signal coming from more than one region. The machine learning model has certain recognition capability on the difference of energy arrangement by utilizing a large amount of data training, and can judge the reaction projection position of the gamma photon according to the energy arrangement.

The above describes an arrangement of the individual readout circuits, i.e. two individual readout circuits per sensor area, for a total of 8 individual readout circuits. However, the above examples are not limiting to the invention, and the individual readout circuits may have other reasonable numbers and arrangements. For example, in another example, the electrical signals of the sensor numbered 3.3 in the A, B, C, D four zones can be read out separately, that is, a separate readout circuit is provided at the center sensor of each zone, and four separate readout circuits are provided, so that the total number of readout channels will be 29. A separate readout circuit placed at the center of each sensor area is sufficient to distinguish the electrical signals from the different sensor areas.

According to the photon detection method provided by the embodiment of the invention, the electric signals output by the sensor are read by the shared reading circuit and the independent reading circuit which are arranged based on the propagation characteristic and the distribution characteristic of the scintillation photons, so that the purpose of reducing the channel can be achieved without influencing the performance of the detector, and the power consumption and the cost of a PET system can be effectively reduced.

According to an embodiment of the invention, the photon detection method 400 further comprises: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals. The energy corresponding to the first number of energy signals is the energy of the high-energy photon. Illustratively, a first number of energy signals may be added to obtain a total energy signal. The total energy signal represents an energy magnitude equal to the energy magnitude of the high-energy photons. Illustratively, the time at which the pulse level occurs earliest in the first number of energy signals may be considered as the arrival time of the high-energy photon. The time of arrival refers to the time of arrival of a high energy photon at the detector, which can be measured by the time of receipt of a scintillation photon by the sensor array. The above-described manner of determining the energy and the arrival time is merely an example, and other manners of determining the energy and/or the arrival time of the high-energy photon may be employed. The energy information and the time information of the high-energy photons can be acquired by a processing circuit described below, and data processing and image reconstruction can be performed on the energy information and the time information to obtain a scan image of the object to be imaged.

The reading circuit is arranged based on the propagation characteristic and the distribution characteristic of the scintillation photons, so that the pertinence and the accuracy of the energy and the arrival time of the high-energy photons obtained by measuring the energy signal output by the reading circuit to the photosensitive area are high. In addition, due to the reduction of the number of channels, the measurement efficiency of energy and time is high.

According to the embodiment of the present invention, step S420 may include: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

The machine learning model may be any suitable intelligent algorithm model, and the invention is not limited to its specific class. Illustratively, the machine learning model may be implemented using decision trees, support vector machines, neural networks, AdaBoost algorithm models, bayesian classifiers, and the like. In the following description, the machine learning model will be described by taking a convolutional neural network as an example.

The machine learning model may be pre-trained or implemented using known models. The machine learning model may classify the reaction projection locations. As described above, the machine learning model has a certain recognition capability for the difference of energy arrangement by using a large amount of data training, and can judge the reaction projection position of the gamma photon according to the energy arrangement. Therefore, the reaction projection position of the gamma photon can be simply, quickly and accurately determined by adopting a machine learning algorithm. The machine learning model outputs position data, in one example, the number of sensors and the number of sensor regions where the sensors are located. For example, following the sensor array example shown in fig. 5, 7a-7d, assuming that the reaction location of the gamma photon is directly above the sensor numbered 2.3 in region a, the machine learning model output may be data indicating region a as well as number 2.3.

According to an embodiment of the present invention, the photon detection method 400 may further include: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

The photon detection method 400 may also include a training step of a machine learning model. Training may be achieved by collecting a number of energy signals reflecting photon reaction events for which the projection locations are known. The photon reaction event simulation can be realized by adopting optical software. And (3) building a model of the PET system by using optical software, and respectively setting different sample reaction positions for simulation so as to obtain energy signals output by the reading circuit at different sample reaction positions. It is preferable that, when the sample reaction position is changed, the sample projection position is also changed as much as possible. The sample projection position is a projection of the sample reaction position on the sensor array. When the sample projection positions of the gamma photons are different, the energy signals output by the readout circuits are different. For example, for each sample projection position, the energy signal corresponding to the sample projection position may be used as an input of the convolutional neural network, and the sample projection position may be used as a target output of the convolutional neural network, and may be trained through a back propagation method.

The machine learning algorithm is an autonomous learning method and can achieve a very good classification effect. After the machine learning model is trained, the model can be used to more accurately locate the reaction projection position according to the actually measured energy signal.

According to an embodiment of the invention, the first number is not smaller than the number of sensors comprised by the maximum radiation range of scintillation photons in the sensor array resulting from the reaction of high-energy photons with the scintillation crystal.

As in the example described above, assuming that the maximum propagation range of scintillation photons in the sensor array contains 5 x 5 number of sensors, the shared readout circuitry should be no less than 25. For example, referring to the examples shown in fig. 5-7d, the number of shared sensing circuits may be 25. Of course, the number of shared readout circuits may be more, for example 36, that is each sensor area may be set to a size of 6 × 6. The area occupied by the sensors connected by the shared readout circuit preferably covers the maximum propagation range of scintillation photons in the sensor array to ensure that substantially all of the energy of scintillation photons produced by a single photon reaction event can be read out by the shared readout circuit.

Illustratively, the second number is not less than N-1, where N is the number of at least two sensor regions. In the case where the first number is equal to N-1, at most one individual readout circuit is assigned to each sensor region. A second number of separate readout circuits is used to assist in identifying the sensor regions in the event that it is not possible to distinguish from which sensor region the first number of energy signals came.

Assuming that the sensor array is divided on average into 4 sensor areas (see fig. 5, 7a-7d), the second number is at least 3. In the case of 3 individual readout circuits, 3 sensor regions are selected from 4 sensor regions, and an individual readout circuit is assigned to each of the 3 sensor regions. In this way, the energy signals read out with 3 separate read-out circuits can also distinguish from which sensor area the energy signals come. It will be appreciated that if the number of individual readout circuits is further reduced, for example only two, this may result in energy signals from two sensor regions to which no individual readout circuit is assigned being indistinguishable in some cases. For example, returning to fig. 5, if two separate readout circuits are provided in the A, B region, and no separate readout circuit is provided in the C, D region, that is, 2+25 to 27 readout channels are provided in total, the distribution laws of the energy signals read out by the 27 channels are the same or approximately the same when the reaction site is directly above the sensor numbered 3.3 in the C region and when the reaction site is directly above the sensor numbered 3.3 in the D region, and thus cannot be distinguished.

In addition to the single readout channel arrangement shown in fig. 5-7d, two other arrangements are proposed in the embodiments of the present invention, as shown in fig. 8a and 8 b. In the arrangement shown in fig. 8a, the signals of 8 channels a3.3, a3.5, B3.3, B5.3, C1.3, C3.3, D3.1, D3.3 are read out separately, and the sensors (m, n) in the remaining A, B, C, D four regions share one channel (

m

1,2,3,4, 5;

n

1,2,3,4,5), for a total of 33 channels. In the arrangement shown in fig. 8B, the signals of the 8 channels a3.3, a4.5, B3.3, B5.2, C1.4, C3.3, D2.1, D3.3 are read out separately, and the sensors (m, n) in the remaining A, B, C, D four regions share one channel (

m

1,2,3,4, 5;

n

1,2,3,4,5), for a total of 33 channels.

Note that the photon detection method provided by the present invention can be applied to discrete crystals or continuous crystals, and does not limit the crystal and crystal array size, SiPM, and SiPM array size. Note that the present invention is not limited to scintillation crystal materials, and LYSO crystals are used as examples only. The scintillation crystal can be any suitable crystal and the invention is not limited thereto. For example, the scintillation crystal may be Bismuth Germanate (BGO), yttrium lutetium silicate (LYSO), or lanthanum bromide (LaBr3), among others. The invention does not limit the coupling mode of the SiPM array and the scintillation crystal, and the SiPM array and the scintillation crystal can be directly coupled or coupled through optical glue and the like.

The sensors described herein may be any suitable photosensor, such as a PMT, SiPM, or Avalanche Photodiode (APD), among others. Although the invention is described herein primarily with respect to sipms as an example, it is not intended to be limiting and the invention may be applied to other similar detectors requiring channel reduction techniques.

The number of shared readout circuits described herein depends on the thickness of the crystal and lightguide layers and the distance the scintillation photons travel in the crystal or lightguide. The number of shared sensing circuits can also be determined when the propagation distance is determined. There are many ways to select the individual readout circuits, and the invention is not limited to the selection, arrangement and number of individual readout circuits. The invention proposes the idea of regularly sharing and individually setting the readout circuits according to the photon propagation characteristics. And calculating the reaction projection position of the gamma photon according to the signal characteristics of the energy signal output by the reading circuit.

According to embodiments of the present invention, the sensor array may be divided into any number of combinations of sensor regions, such as 2 × 1, 3 × 2, 2 × 4, 4 × 4, and so on. The number and arrangement of the sensor regions included in the sensor array may be set as desired, but the present invention is not limited thereto. For example, if the scintillation crystal is a continuous crystal of 60mm × 60mm × 20mm and the propagation distance of scintillation photons in the sensor is 10mm, photon detection may be performed using a sensor array divided into 3 × 3 sensor regions (each having a size of 20mm × 20mm), and if the propagation distance of scintillation photons in the sensor is 15mm, photon detection may be performed using a sensor array divided into 2 × 2 sensor regions (each having a size of 30mm × 30 mm).

According to another aspect of the invention, a photon detection apparatus is provided. FIG. 9 shows a schematic block diagram of a photon detection apparatus 900 according to one embodiment of the present invention. As shown in fig. 9, the photon detection apparatus 900 includes a sensor array 910, readout circuitry 920, and processing circuitry 930. In the above description of the photon detection method 400, the circuit structure and the operating principle of the scintillation crystal, the sensor array, the readout circuit have been described. The processing circuitry is used to implement the various steps/functions of the photon detection method 400. Those skilled in the art can understand the circuit structure and the operation principle of the photon detection apparatus 900 with reference to the above description of the photon detection method 400, and will not be described in detail.

The sensor array 910 is coupled to the scintillation crystal for detecting scintillation photons generated by the reaction of the high energy photons with the scintillation crystal, wherein the sensor array 910 is divided into at least two sensor regions on average.

Readout circuitry 920 is coupled to sensor array 910 for receiving electrical signals output by sensor array 910 and outputting energy signals related to the energy of the high-energy photons, wherein readout circuitry 920 includes a first number of shared readout circuits equal to the number of sensors in each sensor region and a second number of individual readout circuits coupled to all sensors in each sensor region in a one-to-one correspondence, each individual readout circuit coupled to a single sensor in the sensor array.

The processing circuit 930 is configured to receive the first number of energy signals respectively output by the first number of shared readout circuits and the second number of energy signals respectively output by the second number of individual readout circuits, and determine a reaction projection position of the high-energy photon based on an energy distribution rule of the first number of energy signals and the second number of energy signals, where the reaction projection position is a projection of the reaction position of the high-energy photon in the scintillation crystal on the sensor array 910. The processing circuit 930 may be implemented using any suitable hardware, software, and/or firmware. Illustratively, the processing circuit 930 may be implemented using a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), a Complex Programmable Logic Device (CPLD), a Micro Control Unit (MCU), or a Central Processing Unit (CPU), etc.

Illustratively, the processing circuit 930 is further configured to determine the energy and/or arrival time of the high-energy photon based on the first number of energy signals.

Illustratively, the first number is no less than the number of sensors that are encompassed by the maximum radiation range in the sensor array 910 of scintillation photons produced by the reaction of the high energy photons with the scintillation crystal.

According to another aspect of the present invention, a photon detection apparatus is provided. FIG. 10 shows a schematic block diagram of a photon detection apparatus 1000 according to one embodiment of the invention.

As shown in fig. 10, the photon detection apparatus 1000 according to the embodiment of the present invention includes a receiving module 1010 and a position determination module 1020. The various modules may perform the various steps/functions of the photon detection method described above in connection with fig. 1-8b, respectively. Only the main functions of the components of the photon detection device 1000 will be described below, and details that have been described above will be omitted.

The receiving module 1010 is configured to receive a first number of energy signals respectively output by a first number of shared readout circuits connected to the sensor array and a second number of energy signals respectively output by a second number of individual readout circuits, where the sensor array is averagely divided into at least two sensor regions, the first number is equal to the number of sensors in each sensor region, the first number of shared readout circuits is connected to all sensors in each sensor region in a one-to-one correspondence, and each individual readout circuit is connected to a single sensor in the sensor array.

The position determining module 1020 is configured to determine a reaction projection position of the high-energy photon based on an energy distribution law of the first number of energy signals and the second number of energy signals, where the reaction projection position is a projection of the reaction position of the high-energy photon in the scintillation crystal coupled to the sensor array on the sensor array.

Illustratively, the photon detection apparatus 1000 may further include: an energy or time determination module (not shown) for determining the energy and/or arrival time of the high energy photons based on the first number of energy signals.

Illustratively, the location determination module 1020 may include: and the input submodule is used for inputting the first number of energy signals and the second number of energy signals into the machine learning model for analysis so as to obtain position data which is output by the machine learning model and is about the reaction projection positions of the high-energy photons.

Illustratively, the photon detection apparatus 1000 may further include: a simulation module for performing photon reaction event simulation at a sample reaction location to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction location, wherein a sample projection location corresponding to the sample reaction location is known; and the training module is used for taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model, taking the position data about the projection positions of the samples as the target output of the machine learning model, and training the machine learning model.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

FIG. 11 shows a schematic block diagram of a photon detection system 1100 in accordance with one embodiment of the invention. The photon detection system 1100 includes a signal acquisition device 1110, a storage device 1120, and a processor 1130.

The signal acquisition device 1110 is used to acquire an energy signal related to the energy of the high-energy photons. The signal acquisition device 1110 is optional and the photon detection system 1100 may not include the signal acquisition device 1110. In this case, the energy signal may be collected by other signal collecting means and the collected signal may be transmitted to the photon detection system 1100.

The storage 1120 stores computer program instructions for implementing the corresponding steps in a photon detection method according to an embodiment of the present invention.

The processor 1130 is configured to run the computer program instructions stored in the storage device 1120 to perform the corresponding steps of the photon detection method according to the embodiment of the present invention, and is configured to implement the receiving module 1010 and the position determination module 1020 in the photon detection apparatus 1000 according to the embodiment of the present invention.

In one embodiment, the computer program instructions, when executed by processor 1130, are for performing the steps of: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining a reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

In one embodiment, the computer program instructions, when executed by the processor 1130, are further for performing the steps of: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals.

In one embodiment, the step of determining the reactive projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, which the computer program instructions are for execution by processor 1130 when executed, comprises: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

In one embodiment, the computer program instructions, when executed by the processor 1130, are further for performing the steps of: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

In one embodiment, the first number is not less than the number of sensors that are encompassed by a maximum radiation range of scintillation photons in the sensor array that are generated by the reaction of the high energy photons with the scintillation crystal.

In one embodiment, co-ordinated sensors in different sensor areas share the same shared readout circuitry.

In one embodiment, the second number is not less than N-1, where N is the number of at least two sensor regions.

Furthermore, according to an embodiment of the present invention, there is also provided a storage medium on which program instructions are stored, which when executed by a computer or a processor are used for executing the respective steps of the photon detection method according to an embodiment of the present invention and for implementing the respective modules in the photon detection apparatus according to an embodiment of the present invention. The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a computer, a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM), a portable compact disc read only memory (CD-ROM), a USB memory, or any combination of the above storage media.

In one embodiment, the program instructions, when executed by a computer or processor, may cause the computer or processor to implement the various functional modules of the photon detection apparatus according to the embodiment of the present invention and/or may perform the photon detection method according to the embodiment of the present invention.

In one embodiment, the program instructions are operable when executed to perform the steps of: receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and determining a reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

In one embodiment, the program instructions are further operable when executed to perform the steps of: the energy and/or arrival time of the high-energy photon is determined based on the first number of energy signals.

In one embodiment, the step of determining the reaction projection position of the high-energy photon based on the energy distribution law of the first number of energy signals and the second number of energy signals, which the program instructions are configured to execute when running, comprises: the first number of energy signals and the second number of energy signals are input to a machine learning model for analysis to obtain position data output by the machine learning model regarding the reaction projection locations of the high-energy photons.

In one embodiment, the program instructions are further operable when executed to perform the steps of: performing photon reaction event simulation at the sample reaction locations to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction locations, wherein sample projection locations corresponding to the sample reaction locations are known; and training the machine learning model by taking the first number of sample energy signals and the second number of sample energy signals as the input of the machine learning model and taking the position data about the projection positions of the samples as the target output of the machine learning model.

The modules in a photon detection system according to embodiments of the present invention may be implemented by a processor of an electronic device implementing photon detection according to embodiments of the present invention executing computer program instructions stored in a memory, or may be implemented when computer instructions stored in a computer readable storage medium of a computer program product according to embodiments of the present invention are executed by a computer.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the foregoing illustrative embodiments are merely exemplary and are not intended to limit the scope of the invention thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as set forth in the appended claims.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another device, or some features may be omitted, or not executed.

In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the invention and aiding in the understanding of one or more of the various inventive aspects. However, the method of the present invention should not be construed to reflect the intent: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

It will be understood by those skilled in the art that all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where such features are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

The various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or Digital Signal Processor (DSP) may be used in practice to implement some or all of the functionality of some of the modules in a photon detection apparatus according to embodiments of the present invention. The present invention may also be embodied as apparatus programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present invention may be stored on computer-readable media or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

The above description is only for the specific embodiment of the present invention or the description thereof, and the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of photon detection, comprising:

receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and

determining a reaction projection position of the high-energy photon based on an energy distribution rule of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled with the sensor array on the sensor array.

2. The photon detection method of claim 1, further comprising:

determining an energy and/or arrival time of the high energy photon based on the first number of energy signals.

3. The photon detection method of claim 1, wherein the determining the reaction projection locations of the high-energy photons based on the energy distribution law of the first number of energy signals and the second number of energy signals comprises:

inputting the first number of energy signals and the second number of energy signals into a machine learning model for analysis to obtain position data output by the machine learning model about reaction projection positions of the high-energy photons.

4. The photon detection method of claim 3, further comprising:

performing photon reaction event simulation at a sample reaction location to obtain a first number of sample energy signals and a second number of sample energy signals corresponding to the sample reaction location, wherein a sample projection location corresponding to the sample reaction location is known; and

training the machine learning model with the first number of sample energy signals and the second number of sample energy signals as inputs to the machine learning model and position data about the sample projection positions as target outputs of the machine learning model.

5. The method of photon detection according to claim 1, wherein the first number is not less than the number of sensors that are encompassed by a maximum radiation range of scintillation photons in the sensor array that are generated by the reaction of the high energy photons with the scintillation crystal.

6. The method of detecting photons of claim 1, wherein sensors in different sensor regions whose coordinates are the same share the same shared readout circuitry, wherein the coordinates of a sensor are the location of that sensor in its sensor region.

7. The method of photon detection according to claim 1, wherein the second number is not less than N-1, where N is the number of the at least two sensor regions.

8. A photon detection device, comprising:

the sensor array is coupled with the scintillation crystal and used for detecting scintillation photons generated by the reaction of high-energy photons and the scintillation crystal, wherein the sensor array is averagely divided into at least two sensor areas;

a readout circuit connected to the sensor array for receiving the electrical signals output by the sensor array and outputting an energy signal related to the energy of the high energy photons, wherein the readout circuit comprises a first number of shared readout circuits and a second number of individual readout circuits, the first number being equal to the number of sensors in each sensor region, and the first number of shared readout circuits connecting all sensors in each sensor region in a one-to-one correspondence, each individual readout circuit connecting a single sensor in the sensor array;

and the processing circuit is used for receiving a first number of energy signals respectively output by the first number of shared readout circuits and a second number of energy signals respectively output by the second number of independent readout circuits, and determining a reaction projection position of the high-energy photon based on an energy distribution rule of the first number of energy signals and the second number of energy signals, wherein the reaction projection position is a projection of the reaction position of the high-energy photon in the scintillation crystal on the sensor array.

9. The photon detection apparatus of claim 8, wherein the processing circuit is further configured to determine an energy and/or arrival time of the high-energy photon based on the first number of energy signals.

10. The photon detection apparatus of claim 8, wherein the first number is no less than a number of sensors that are encompassed by a maximum radiation range of scintillation photons in the sensor array that are generated by the reaction of the high energy photons with the scintillation crystal.

11. The photon detection apparatus of claim 8, wherein sensors in different sensor regions whose coordinates are coincident share the same shared readout circuitry, wherein the coordinates of a sensor are the location of that sensor in the sensor region in which it is located.

12. The photon detection apparatus of claim 8, wherein the second number is not less than N-1, where N is the number of the at least two sensor regions.

13. A photon detection device, comprising:

the receiving module is used for receiving a first number of energy signals respectively output by a first number of shared readout circuits connected with a sensor array and a second number of energy signals respectively output by a second number of independent readout circuits, wherein the sensor array is averagely divided into at least two sensor areas, the first number is equal to the number of sensors in each sensor area, the first number of shared readout circuits are connected with all the sensors in each sensor area in a one-to-one correspondence manner, and each independent readout circuit is connected with a single sensor in the sensor array; and

a position determining module, configured to determine a reaction projection position of the high-energy photon based on an energy distribution rule of the first number of energy signals and the second number of energy signals, where the reaction projection position is a projection of the reaction position of the high-energy photon in a scintillation crystal coupled to the sensor array on the sensor array.

14. A photon detection system comprising a processor and a memory, wherein the memory has stored therein computer program instructions that, when executed by the processor, are operable to perform the steps of:

15. A storage medium having stored thereon program instructions which when executed are for performing the steps of: