PET detectors and PET equipment

Abstract

This application relates to a PET detector and a PET device. The PET detector includes a photoelectric conversion array, which comprises multiple photoelectric converters arranged in an array. A readout circuit assembly includes an insulating substrate, a thin-film electrode disposed on one side of the insulating substrate, and a copper plating layer disposed on the other side of the insulating substrate. The readout circuit assembly is disposed on the photoelectric conversion array, and the thin-film electrode is in electrical contact with the photoelectric conversion array. Current output terminals are provided at each of the four corners of the thin-film electrode, and signal output terminals are provided on the copper plating layer. When current from the photoelectric conversion array flows into the thin-film electrode, time information is obtained through the signal output terminals of the copper plating layer. The PET detector of this application can accurately obtain the position and time information of the PET signal.

Description

Technical Field

[0001] This application generally relates to the field of electronic information technology. More specifically, this application relates to a PET detector and a PET device. Background Technology

[0002] Positron emission tomography (PET) is an advanced nuclear medicine imaging device that primarily converts light signals into electrical signals and records and processes these electrical signals. The main physical quantities recorded are the time and energy information of the light signal. Current main methods for reading this information include single-channel readout, resistor network readout, and row-column readout.

[0003] The single-channel readout method is the most intuitive readout method and, in principle, best preserves the necessary time and energy information. However, when the number of output channels is too large, it poses a significant challenge to engineering implementation and cost.

[0004] Resistor network readout can reduce the number of readout channels, but each individual SiPM pixel loses precise timing information after passing through the channel compression circuit, and the original timing information cannot be preserved.

[0005] Row-column readout can compress the channel, reading out a row or a column. Compared to resistive mesh readout, time information can be preserved to some extent, but there is still a significant loss. Summary of the Invention

[0006] This application provides a PET detector and a PET device to solve the problem of easy loss of information detection in existing PET devices.

[0007] To address the aforementioned technical problems, this application proposes a PET detector, comprising: a photoelectric conversion array including multiple photoelectric converters arranged in an array; and a readout circuit assembly including an insulating substrate, a thin-film electrode disposed on one side of the insulating substrate, and a copper plating layer disposed on the other side of the insulating substrate; the readout circuit assembly is disposed on the photoelectric conversion array, and the thin-film electrode is in electrical contact with the photoelectric conversion array; each of the four corners of the thin-film electrode is provided with a current output terminal, and the copper plating layer is provided with a signal output terminal; when the current from the photoelectric conversion array flows into the thin-film electrode, time information is obtained through the signal output terminal of the copper plating layer.

[0008] In one embodiment, the thin-film electrode is provided with a plurality of welding points arranged in an array, the welding points corresponding to the photoelectric converter, and the photoelectric converter is connected to the thin-film electrode through the welding points.

[0009] In one embodiment, the photoelectric converter is a silicon photomultiplier tube.

[0010] In one embodiment, the thin-film electrode and the copper plating layer are of the same size and are disposed correspondingly.

[0011] In one embodiment, the signal output terminal is located at the center of the copper cladding layer.

[0012] In one embodiment, the copper cladding layer consists of at least one complete copper layer, which is square or honeycomb-shaped.

[0013] In one embodiment, the insulating substrate is alumina ceramic or aluminum nitride ceramic.

[0014] In one embodiment, the thin-film electrode and the copper plating layer are formed on the insulating substrate by an evaporation or sputtering process.

[0015] In one embodiment, the readout circuit assembly further includes a low-noise amplifier and a high-speed comparator, with the signal output terminal of the copper layer connected to the low-noise amplifier and the low-noise amplifier connected to the high-speed comparator.

[0016] To address the aforementioned technical problems, this application proposes a PET device, which includes the aforementioned PET detector.

[0017] Unlike existing technologies, the PET detector of this application includes a photoelectric conversion array comprising multiple photoelectric converters arranged in an array; a readout circuit assembly comprising an insulating substrate, a thin-film electrode disposed on one side of the insulating substrate, and a copper plating layer disposed on the other side of the insulating substrate; the readout circuit assembly is disposed on the photoelectric conversion array, and the thin-film electrode is in electrical contact with the photoelectric conversion array; current output terminals are provided at each of the four corners of the thin-film electrode, and signal output terminals are provided on the copper plating layer; when the current from the photoelectric conversion array flows into the thin-film electrode, time information is obtained through the signal output terminals of the copper plating layer. The PET detector of this application accurately obtains the position information of the PET signal using the four current output terminals of the thin-film electrode and determines the time information using the copper plating layer. Attached Figure Description

[0018] The above and other objects, features, and advantages of exemplary embodiments of the present disclosure will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the present disclosure are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0019] Figure 1 This is a schematic diagram of the PET detector of this application;

[0020] Figure 2This is a schematic diagram of the PET detector signal reading process in this application. Detailed Implementation

[0021] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0022] The specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of the PET detector used in this application. The PET detector is an important component of molecular imaging equipment such as PET and PET / CT. The material composition, structural design, and performance of the PET detector directly affect the clinical and research applications of molecular imaging equipment such as PET and PET / CT, and the quality of the detector directly determines the quality of the PET system.

[0023] The PET detector 100 in this embodiment includes a crystal, a photoelectric conversion array 11, and a readout circuit assembly 12.

[0024] Crystals are used to convert gamma photons into visible light, specifically scintillation crystals. There are four main types: BGO, LYSO, LSO, and LBS. Among these, LYSO, LSO, and LBS crystals contain lutetium, resulting in a significantly reduced afterglow time. It is generally considered that a crystal afterglow time of less than 80 ns (nanoseconds) is sufficient for Time-of-Flight (TOF) technology. However, lutetium-containing crystals (LSO, LYSO) also have drawbacks, namely their inherent background radioactivity and relatively low effective atomic number, leading to reduced X-ray detection efficiency. Therefore, the optimal length for LYSO, LSO, and LBS crystals in PET detectors is generally around 20 mm. Thus, if LYSO, LSO, or LBS crystals are chosen, TOF technology must be incorporated to compensate for or overcome their inherent low detection efficiency.

[0025] The photoelectric conversion array 11 is used to convert visible light (fluorescence) generated by the interaction of gamma rays with a crystal into an electrical signal. In this embodiment, the photoelectric conversion array 11 can be one of three types: photomultiplier tube (PMT), silicon photomultiplier tube (SiPM), or digital photon counting (DPC).

[0026] Specifically, in this embodiment, the photoelectric conversion array 11 includes multiple photoelectric converters 111 arranged in an array, which is a SiPM array with M×N channels. Figure 1 In the embodiment shown, a 4×4 array is used.

[0027] The readout circuit assembly 12 is used to acquire the signals output by the photoelectric conversion array 11, that is, it is disposed on the photoelectric conversion array 11 and is used to acquire signals from M×N channels. It mainly includes an insulating substrate 121, a thin film electrode 122, and a copper cladding layer 123.

[0028] The insulating substrate 121 serves as the support substrate for the thin-film electrode 122 and the copper cladding layer 123, ensuring the strength of both and separating them to prevent mutual interference. Specifically, it can be made of alumina ceramic or aluminum nitride ceramic.

[0029] Thin-film electrodes 122 and copper cladding layers 123 are respectively disposed on both sides of insulating substrate 121, specifically formed on insulating substrate 121 using a coating process, such as evaporation or sputtering. Thin-film electrodes 122 can be germanium. Compared with discrete components such as capacitors and resistors, the coating process provides better product consistency and scalability.

[0030] The thin-film electrode 122 is in electrical contact with the photoelectric conversion array 11 to receive the current signal from the photoelectric conversion array 11, thereby obtaining the energy and position information of the current signal. The energy information is the magnitude of the current signal, and the position information is the specific photoelectric converter 111 that emitted it.

[0031] Specifically, multiple solder points 1222 are arranged in an array on the thin-film electrode 122. Each solder point 1222 corresponds to a photoelectric converter 111, and the number of solder points 1222 is the same as the number of photoelectric converters 111, with corresponding positions. Each photoelectric converter 111 is connected to the thin-film electrode 122 via the solder points 1222. The current signal from the photoelectric converter 111 directly enters the thin-film electrode 122 and diffuses within it.

[0032] A current output terminal 1221 is provided at each of the four corners of the thin film electrode 122. The position of the current signal entering the thin film can be calculated by the current collected by the current output terminal 1221 at the four corners, and then the position information and energy information of the current signal can be determined.

[0033] In this embodiment, the arrangement of four current output terminals 1221 compresses the M×N channels in the photoelectric conversion array 11 into four channels, reducing the burden on the readout circuit assembly 12. While the location information of the current signal can be determined through the four current output terminals 1221, the timing information of the initial current signal cannot be obtained using the current output terminals 1221 because the paths from each photoelectric converter to the current output terminals 1221 are different. Therefore, in this embodiment, the signal output terminal 1231 of the copper layer 123 is also used to detect timing information.

[0034] A signal output terminal 1231 is provided on the copper layer 123. When the current signal enters the thin film electrode 122 and diffuses therein, the induced signal is sensed in the copper layer 123. The induced signal is led out through the signal output terminal 1231, thereby obtaining the time information of the current signal. The time information indicates the time when the photoelectric converter generates the current signal. The time can be quickly determined by sensing the copper layer 123.

[0035] The copper cladding layer 123 and the thin-film electrode 122 are the same size and are correspondingly positioned to ensure the sensing of the current diffused in the thin-film electrode 122. The signal output terminal 1231 is specifically located at the center of the copper cladding layer 123. The path from the center to different sensing positions is relatively short, so it has little impact on the determination of the timing.

[0036] The copper cladding layer 123 can also be composed of at least one copper layer, which can be square or honeycomb-shaped. For example, it can be a single, complete copper layer with a signal output terminal; or it can be two or more copper layers spliced ​​together, each independent of the others and each equipped with a signal output terminal, which is also used to sense the diffusion current in the thin-film electrode 122. Setting the copper layers to square or honeycomb shape can ensure that no large gaps are generated during splicing, so that the thin-film electrode 122 can be covered.

[0037] Signal processing elements can also be provided at the signal output terminal 1231 of the copper layer 123. The readout circuit assembly 12 also includes a low-noise amplifier and a high-speed comparator. The signal output terminal 1231 is connected to the low-noise amplifier, and the low-noise amplifier is connected to the high-speed comparator. The low-noise amplifier first amplifies the signal, and then the high-speed comparator performs timing discrimination to generate a standard pulse, thereby obtaining high-precision time information.

[0038] The PET detector of this application can simultaneously achieve channel compression, energy information acquisition, and time information acquisition of the readout circuit assembly.

[0039] like Figure 2 , Figure 2 This is a schematic diagram of the PET detector signal reading process of this application. The signal reading process of the PET detector of this application specifically includes the following steps.

[0040] S11: The photoelectric conversion array converts optical signals into electrical signals.

[0041] S12: The thin-film electrode acquires electrical signals and outputs signals through four current output terminals to determine the energy and position information of the electrical signals.

[0042] S13: The current in the copper-clad layer sensing thin film electrode generates an induced signal, which is output by the signal output terminal to determine the timing information of the electrical signal.

[0043] This application also proposes a PET device comprising multiple of the aforementioned PET detectors, which can be used in medical clinical and research applications.

[0044] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] Based on the above description in this specification, those skilled in the art will also understand that the following terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present application and simplifying the description, and do not explicitly or implicitly suggest that the device or element involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present application.

[0046] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0047] While this specification has shown and described numerous embodiments of the present application, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and intent of the present application. It should be understood that various alternatives to the embodiments of the present application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover modular compositions, equivalents, or alternatives within the scope of these claims.

Claims

1. A PET detector, characterized in that, The PET detector includes: A photoelectric conversion array, comprising multiple photoelectric converters arranged in an array; A readout circuit assembly, the readout circuit assembly including an insulating substrate, a thin film electrode disposed on one side of the insulating substrate, and a copper plating layer disposed on the other side of the insulating substrate; The readout circuit assembly is disposed on the photoelectric conversion array, and the thin film electrode is in electrical contact with the photoelectric conversion array; The thin-film electrode has a current output terminal at each of its four corners, and the copper plating layer has a signal output terminal. When the current from the photoelectric conversion array flows into the thin-film electrode, time information is obtained through the signal output terminal of the copper plating layer.

2. The PET detector according to claim 1, characterized in that, The thin-film electrode has multiple welding points arranged in an array, each welding point corresponding to the photoelectric converter, and the photoelectric converter is connected to the thin-film electrode through the welding points.

3. The PET detector according to claim 2, characterized in that, The photoelectric converter is a silicon photomultiplier tube.

4. The PET detector according to claim 1, characterized in that, The thin-film electrode and the copper-clad layer are the same size and are arranged accordingly.

5. The PET detector according to claim 4, characterized in that, The signal output terminal is located at the center of the copper cladding layer.

6. The PET detector according to claim 4, characterized in that, The copper cladding layer consists of at least one copper layer, which is square or honeycomb-shaped.

7. The PET detector according to claim 1, characterized in that, The insulating substrate is alumina ceramic or aluminum nitride ceramic.

8. The PET detector according to claim 1, characterized in that, The thin-film electrode and the copper-clad layer are formed on the insulating substrate by evaporation or sputtering processes.

9. The PET detector according to claim 1, characterized in that, The readout circuit assembly further includes a low-noise amplifier and a high-speed comparator. The signal output terminal of the copper layer is connected to the low-noise amplifier, and the low-noise amplifier is connected to the high-speed comparator.

10. A PET device, characterized in that, The PET device includes a plurality of PET detectors as described in any one of claims 1-9.

Images