Detector of SPECT imaging system, SPECT imaging system and SPECT imaging method

Abstract

The invention provides a detector of an SPECT imaging system, the SPECT imaging system and an SPECT imaging method. The detector of the SPECT imaging system comprises a plurality of detector units, and the plurality of detector units are arranged in a first direction; each detector unit comprises a plurality of detector modules arranged in a second direction, the second direction is perpendicular to the first direction, each detector module comprises a scintillation crystal array, an SiPM detector array and a preprocessing device which are sequentially arranged in a third direction, and the third direction, the first direction and the second direction are perpendicular to one another; the scintillation crystal array comprises a plurality of scintillation crystal blocks arranged in an array, the SiPM detector array comprises a plurality of SiPM detector pixels arranged in an array, and the scintillation crystal blocks and the SiPM detector pixels are arranged in a one-to-one correspondence manner. According to the detector, the spatial uniformity is remarkably improved, and the imaging quality is further improved.

Description

[0001] The present disclosure claims priority to the Chinese patent application No. 202510470966.X, with the application date of April 15, 2025, the title of which is “SPECT imaging system’s detector, SPECT imaging system and SPECT imaging method”, the content of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to a SPECT imaging system’s detector, a SPECT imaging system and a SPECT imaging method. BACKGROUND

[0003] SPECT imaging system (Single-Photon Emission Computed Tomography) is a single photon emission computed tomography device, which displays the metabolic activity of the examined organs or tissues by detecting the absorption distribution of radioactive drugs in the patient’s body, and realizes the clinical image judgment of nuclear medicine.

[0004] It should be noted that the statements in this background section merely provide background information related to the present disclosure and do not necessarily constitute prior art. SUMMARY

[0005] The present disclosure provides a SPECT imaging system’s detector, a SPECT imaging system and a SPECT imaging method to improve the imaging quality.

[0006] The first aspect of the present disclosure provides a SPECT imaging system’s detector, comprising:

[0007] a plurality of detector units, the plurality of detector units are arranged in a first direction; and each detector unit comprises a plurality of detector modules arranged in a second direction, the second direction is perpendicular to the first direction, the detector module comprises a scintillation crystal array, a SiPM detector array and a preprocessing device arranged in a third direction in sequence, the third direction, the first direction and the second direction are perpendicular to each other, the scintillation crystal array comprises a plurality of scintillation crystal blocks arranged in an array, the SiPM detector array comprises a plurality of SiPM detector pixels arranged in an array, and the scintillation crystal blocks and the SiPM detector pixels are arranged one by one.

[0008] In some embodiments, the scintillation crystal block is a strip structure; and / or, the scintillation crystal block is a square strip structure.

[0009] In some embodiments, the scintillation crystal block comprises cesium iodide scintillation crystal.

[0010] In some embodiments, a reflective material is arranged between the plurality of scintillation crystal blocks; and / or, an optical silicone oil is used to couple between the scintillation crystal array and the SiPM detector array.

[0011] In some embodiments, the detector further comprises a rack and a side shield, the rack comprises two side plates respectively located at two ends in the first direction and a support arranged between the two side plates, the two side plates and the support jointly enclose a containing space for placing the plurality of detector units, and the side shield is arranged between the rack and the detector units.

[0012] In some embodiments, the side shield is arranged to be attached to the inner surface of the rack and the detector units.

[0013] In some embodiments, the side shield is made of tungsten or tungsten alloy.

[0014] In some embodiments, the detector further comprises a back shield arranged on a side of the plurality of detector units away from the scintillation crystal array in the third direction.

[0015] In some embodiments, the detector comprises a rack, the detector unit further comprises a shell and a cover, the plurality of detector modules are arranged in the inner cavity of the shell, and the cover is attached to the opening of the shell to enclose the shell.

[0016] In some embodiments, the cover is connected to the rack so that the detector unit is hung on the rack.

[0017] In some embodiments, the extension length of the cover in the second direction is greater than the extension length of the shell in the second direction so that the two ends of the cover are overlapped on the rack.

[0018] In some embodiments, the two ends of the cover are provided with connecting holes, and the cover is connected to the rack through the connecting holes, the connecting holes comprise long holes, and the length direction of the long holes extends along the first direction.

[0019] In some embodiments, the shell is made of a composite material; or, the shell is made of a carbon fiber material.

[0020] In some embodiments, the detector further comprises a collimator arranged on the lower side of the plurality of detector units, and a guard plate is arranged between the collimator and the plurality of detector units.

[0021] In some embodiments, every two adjacent detector units in the plurality of detector units are arranged to be attached; and / or, every two adjacent detector modules in the plurality of detector modules are arranged to be attached.

[0022] The second aspect of the present disclosure provides a SPECT imaging system comprising the above detector.

[0023] The third aspect of the present disclosure provides a SPECT imaging method, comprising detecting by using the above detector or the above SPECT imaging system, comprising the following steps:

[0024] The signals of the channels corresponding to each SiPM detector pixel are independently energy corrected and energy discriminated.

[0025] The detector of the SPECT imaging system provided by the embodiments of the present disclosure adopts a scintillation crystal array formed by a plurality of scintillation crystal blocks and a SiPM detector array formed by a plurality of detector pixels, and the scintillation crystals of the scintillation crystal array are arranged one by one corresponding to the detector pixels of the detector array, so that the gamma rays emitted from each scintillation crystal are received and output by the corresponding SiPM detector pixel, that is, even the gamma rays emitted from the scintillation crystal blocks located at the edge of the scintillation crystal array can be converted into electrical signals by the SiPM detector corresponding thereto, and the accurate detection of the rays at the edge can be realized, so that the effective field of view area of the detector module is the same as that of the scintillation crystal array, and the effective field of view area of the detector is enlarged, the spatial uniformity is significantly improved, and the imaging quality is improved.

[0026] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the present disclosure, constitute a part of this application, and the illustrative embodiments of the present disclosure and their description serve to explain the present disclosure, and do not limit the present disclosure in any way. In the drawings:

[0028] Figure 1 A perspective structural schematic diagram of the detector of some embodiments of the present disclosure.

[0029] Figure 2 A front structural schematic diagram of the detector of some embodiments of the present disclosure.

[0030] Figure 3 A Figure 2 A local enlarged schematic diagram of the M part.

[0031] Figure 4 A side structural schematic diagram of the detector of some embodiments of the present disclosure.

[0032] Figure 5 An exploded structural schematic diagram of the detector unit of some embodiments of the present disclosure.

[0033] Figure 6Exploded view of a detector module for some embodiments of the present disclosure.

[0034] Figure 7 Positioning diagram for head scan using PMT detectors.

[0035] Figure 8 Positioning diagram for head scan using SiPM detectors of embodiments of the present disclosure.

[0036] Figure 9 Positioning diagram for heart scan using PMT detectors.

[0037] Figure 10 Positioning diagram for heart scan using SiPM detectors of embodiments of the present disclosure.

[0038] Figure 11 Structure diagram of a SPECT-CT system using PMT detectors.

[0039] Figure 12 Structure diagram of a SPECT-CT system using SiPM detectors.

[0040] Reference signs:

[0041] 100, gantry; 101, support; 102, side plate; 103, collimator rail; 104, collimator; 105, guard plate; 106, back shield; 107, side shield; 108, fixing structure; 109, circuit board support structure;

[0042] 200, detector unit; 201, data processing circuit board; 202, data transmission circuit board; 203, cover; 2031, connecting hole; 204, housing; 206, wire outlet hole; 210, detector module; 211, scintillation crystal array; 2111, scintillation crystal block; 212, SiPM detector array; 2121, SiPM detector pixel; 213, pre-processing device;

[0043] 301, patient head; 401, headrest; 402, PMT detector; 503, effective field of view area; 505, probe dead zone; 403, SiPM detector; 504, effective field of view area; 506, probe dead zone; 302, patient torso; 508, probe angle dead zone; 507, probe angle dead zone; 406, CT system; 407, SPECT gantry; 404, motion control structure. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present disclosure will be described clearly and completely in the embodiments of the present disclosure in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The description of the at least one example embodiment is actually only illustrative, but not as any limitation on the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present disclosure.

[0045] Unless specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in the examples herein are not meant to limit the scope of the present disclosure. Also, it is to be understood that the dimensions of the various parts shown in the drawings are not necessarily to scale. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the present disclosure. In all examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of the example embodiments can have different values. It is noted that like numbers and letters refer to like elements throughout the several views of the drawings, and thus, once an element is defined in one drawing that is common to multiple drawings, further discussion of the same element in the other drawings is not necessary.

[0046] For the sake of description, spatial relative terms, such as "on", "above", "upper surface", "upper", and the like, can be used herein to describe the spatial relationship between one device or feature and another device or feature as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "on" the other device or structure will be positioned "below" or "under" the other device or structure. Thus, the example term "above" can include both "above" and "below". The device can also be positioned in other different ways, and the spatial relative descriptions used herein are interpreted accordingly.

[0047] The principle of the SPECT imaging system is based on the single photon generated by the radionuclide decay. Through collimation, detection, data acquisition and processing, etc., a tomographic image reflecting the distribution of the radioactive drug in the body is finally formed.

[0048] The detection mode of the SPECT imaging system is mainly based on physical collimation and energy discrimination: the SPECT uses a radioactive isotope drug that generates a single gamma photon, and the direction of the generated gamma photon is random. When the direction of the gamma ray is the same as the collimation direction, the gamma ray is shot into the scintillation crystal through the collimator. When the direction of the gamma ray is different from the collimation direction, the gamma ray is blocked or changed in direction and energy by the collimator, which is usually referred to as scattering. Most of the scattered gamma photons cannot be shot into the scintillation crystal, and a small amount of the scattered gamma photons can be shot into the scintillation crystal and lose part of the energy. When the signal is processed, the energy of the signal is calculated, and whether the energy meets the energy requirement is discriminated through a set energy window. The signal that meets the energy requirement is discriminated as an effective event, and the signal energy outside the energy window is considered as an ineffective event. The effective signal after collimation and energy discrimination is considered to occur on the extension line along the collimation direction. The signal energy can be equivalent to the amplitude integral of the signal, which can be simplified as the amplitude of the signal. A gamma photon of a specific energy will generate a specific amount of optical signal in the scintillation crystal, which is further converted into a specific amount of electrical signal. For a specified nuclide, the signal energy after detection and processing can be counted as a data spectrum, usually referred to as an energy spectrum or a spectrum. Therefore, the SPECT imaging system pays more attention to the energy information, and the accuracy of the energy information is very important in signal processing. Moreover, the SPECT imaging system usually uses a flat panel probe, so the scanning plane image is more used during use. Therefore, the uniformity of the probe in the plane is required to be higher, that is, the uniformity of the response of the detector to the incident photons in the entire detection area is required to be higher.

[0049] Based on the higher requirement of the SPECT system for uniformity, the scintillation crystal blocks of the scintillation crystal array used in this embodiment are cut into long strips and bonded together using a reflective material to form a block-shaped crystal array. Moreover, the scintillation crystals of the scintillation crystal array are arranged one-to-one with the detector pixels of the detector array, so that the gamma rays shot from each scintillation crystal are received and output by the corresponding SiPM detector pixels, that is, even the gamma rays shot from the scintillation crystal blocks 2111 located at the edge of the scintillation crystal array 211 can be converted into electrical signals by the SiPM detectors corresponding thereto, so that the resolution capability of all positions in the range covered by the crystal array is consistent, and therefore accurate position detection and imaging of the rays can be realized. In other words, the scintillation crystal blocks of the scintillation crystal array of this embodiment are uniformly distributed at different positions, so that the output signal of the detector is consistent regardless of the position of the photon incident to the detector.

[0050] Reference Figure 1The SPECT imaging system provided by some embodiments of the present disclosure includes a plurality of detector units 200. The plurality of detector units 200 are arranged in a first direction X. Each detector unit 200 includes a plurality of detector modules 210 arranged in a second direction Y. The second direction Y is perpendicular to the first direction X. For reference Figure 6 The detector module 210 includes a scintillation crystal array 211, a SiPM detector array 212 and a preprocessing device 213 arranged in a third direction Z, the third direction Z, the first direction X and the second direction Y being perpendicular to each other. The scintillation crystal array 211 includes a plurality of scintillation crystal blocks 2111 arranged in an array. The SiPM detector array 212 includes a plurality of SiPM detector pixels 2121 arranged in an array. The scintillation crystal block 2111 and the SiPM detector pixel 2121 correspond to each other.

[0051] The SPECT imaging system provided by the embodiments of the present disclosure uses the scintillation crystal array 211 formed by a plurality of scintillation crystal blocks 2111 and the SiPM detector array 212 formed by a plurality of SiPM detector pixels 2121. The scintillation crystal of the scintillation crystal array and the SiPM detector pixel of the detector array correspond to each other. Thus, the gamma rays emitted from each scintillation crystal are received and output by the corresponding SiPM detector pixel. That is, even the gamma rays emitted from the scintillation crystal block 2111 located at the edge of the scintillation crystal array 211 can be converted into an electrical signal by the corresponding SiPM detector, so that the edge rays can be accurately detected. Therefore, the effective field of view area of the detector module is the same as that of the scintillation crystal array 211, so that the detector module has almost no edge dead zone. Compared with the prior art, the effective field of view area of the detector is enlarged, the spatial uniformity is significantly improved, and the imaging quality is improved.

[0052] Reference Figure 6 The working principle of the detector module 210 is as follows: the gamma rays are emitted into the scintillation crystal block, the scintillation crystal block converts the energy of the gamma rays into visible light of a specific wavelength, the visible light is transmitted along the scintillation crystal block to the detection surface of the SiPM detector, the SiPM detector converts the visible light into an electrical signal, and the electrical signal is processed by the preprocessing device 213 and transmitted to the data processing device at the back end for subsequent processing.

[0053] The detector module 210 of the embodiment of the present disclosure includes a scintillation crystal array 211 formed by a plurality of scintillation crystal blocks and a SiPM detector array 212 formed by a plurality of detector pixels 2121. Since the SiPM detector has a small pixel size and a fine array mechanism, it can more accurately locate the gamma rays, thereby improving the spatial resolution of the image. Therefore, the detector module 210 can effectively improve the intrinsic resolution of the SPECT imaging system and significantly improve the imaging performance and stability of the system. Further, the SiPM detector has a high photoelectric conversion efficiency for gamma rays, which can effectively convert the incident gamma rays into electrical signals, reduce signal loss, and improve detection sensitivity. This enables the SPECT imaging system to obtain sufficient counts in a shorter time, improves the imaging speed, and helps to detect signals in areas with less distribution of radioactive drugs in the body, which is of great significance for the early detection of lesions.

[0054] Further, in terms of system sensitivity, the scintillation crystal blocks 2111 and the SiPM detector pixels 2121 of the present disclosure are arranged one-to-one, which can process multiple events at the same time. Therefore, after injecting a drug with less activity, the detector of the present disclosure can collect more counts in the same time period compared to the conventional detector, which can significantly improve the system sensitivity and improve the image quality. Moreover, the injection dose of the drug is reduced, and the side effects of the drug on the human body are reduced.

[0055] Further, in terms of count rate characteristics, the design of the present disclosure significantly improves the maximum count rate. The count rate, i.e., the number of effective gamma photon events recorded by the detector in a unit of time, directly affects the scanning time and the working efficiency of the system. The conventional SPECT detector, due to the non-one-to-one correspondence between the crystal and the SiPM detector pixel, can only process one event at the same time. If two photons arrive almost simultaneously, the system may not be able to distinguish them, resulting in a loss of counts. Moreover, after injecting a drug with a certain activity, the count will be blocked, resulting in a long scanning time. Due to the limitation of the maximum count rate, the scanning time cannot be shortened. However, due to the one-to-one correspondence between the crystal and the SiPM detector pixel, the present disclosure can process multiple events at the same time, which significantly improves the maximum count rate and thus significantly shortens the scanning time.

[0056] Specifically, referring to Figure 6 The scintillation crystal array 211 of the embodiment of the present disclosure is in a square structure, and the SiPM detector array 212 is also in a square structure. The square structure of the scintillation crystal array 211 and the SiPM detector array 212 is the same size, thereby forming a one-to-one corresponding module structure, as shown in Figure 5As shown, in the third direction Z, the detector module 210 is a stacked structure, the scintillation crystal array 211 is located at the bottom, the SiPM detector array 212 is located above the scintillation crystal array 211, and the preprocessing device 213 is located above the SiPM detector array 212.

[0057] Specifically, the scintillation crystal block 2111 is a square structure, and the SiPM detector is also a square structure, for example, a cube or a cuboid structure. The preprocessing device 213 includes a preprocessing circuit board.

[0058] In some embodiments, the scintillation crystal block 2111 includes a cesium iodide (CsI) scintillation crystal. The cesium iodide (CsI) scintillation crystal can emit strong fluorescence after being excited by a gamma ray, has high luminous efficiency, and has a good matching spectrum response with the SiPM detector, which is conducive to converting the gamma ray into an electrical signal for detection and imaging, and can produce high-quality image signals to improve the contrast and resolution of the image. The cesium iodide (CsI) scintillation crystal has good chemical stability and thermal stability, and is not easy to deteriorate and damage under normal use conditions, thereby reducing the risk of image quality degradation caused by changes in crystal performance and improving the stability of the SPECT imaging system. Further, the cesium iodide (CsI) scintillation crystal is easy to process into various shapes and sizes, and is therefore suitable for use in the scintillation crystal array 211 of the embodiments of the present disclosure. The CsI scintillation crystal is cut and ground into suitable crystal units according to requirements to form an array.

[0059] Reference Figure 6 In some embodiments, the scintillation crystal block 2111 has a strip structure. The light-emitting surfaces of the plurality of strip-shaped scintillation crystal blocks 2111 in the scintillation crystal array 211 are coupled with the SiPM detector pixels, so that the electrical signals of each detector pixel are independently output through the detector backplane in the SiPM detector array, and the preprocessing device 213 integrates the electrical signals of all the detector pixels to output a signal equal to or less than the number of detector pixels, thereby improving the spatial resolution of the detector and the system sensitivity.

[0060] Specifically, as shown in the embodiment shown in FIG. 2B, the scintillation crystal block 2111 has a square strip structure, specifically a cuboid structure, so that the plurality of scintillation crystal blocks 2111 can be closely arranged, and the surfaces of the scintillation crystal array 211 formed by the closely arranged scintillation crystal blocks 2111 are planar, for example, in the embodiment shown in FIG. 2B, the four side surfaces of the scintillation crystal array 211 are planar. Figure 6 Figure 6

[0061] Specifically, the interval between the two adjacent scintillation crystal blocks 2111 is 0.1mm~0.2mm.

[0062] ​​The reflective material is bonded between the plurality of scintillation crystal blocks 2121.

[0063] In some embodiments, optical silicon oil coupling is adopted between the scintillation crystal array 211 and the SiPM detector array 212.

[0064] In some embodiments, the shape of the scintillation crystal block can be designed as a plurality of vertical strip-shaped CsI crystals, and the strip-shaped structure can be made to have a size specification of 3mm x 3mm, so that the resolution can reach 3mm. The resolution of the traditional SPECT detector is about 6mm at most. It can be seen that the design of the present disclosure significantly improves the spatial resolution of the SPECT, so that the image is clearer and the details are more obvious.

[0065] Since the SiPM detector is small in volume and light in weight, it is very suitable to be arranged in an array to form the detector SiPM detector array 212 of the present embodiment, thereby facilitating the formation of the module.

[0066] Reference Figure 1 The detector of some embodiments further comprises a gantry 100. Reference Figures 2 to 5 The detector unit 200 further comprises a shell 204 and a cover 203. A plurality of detector modules 210 are arranged in the inner cavity of the shell 204. The cover 203 is covered at the opening of the shell 204 to close the shell 204. The plurality of detector units 200 of the detector of the present embodiment are arranged in the first direction X, and the cover 203 of each detector unit 200 is connected to the shell 204 to form an integral unit for each detector unit 200. The shell 204 of each detector unit 200 is further provided with a plurality of detector modules 210, and the plurality of detector modules 210 are independent of each other. In this way, when a failure of a detector module is detected, the detector module belonging to the detector unit can be directly located, and then the cover is opened to independently replace or repair the detector module, without the need to disassemble the entire detector unit, thereby greatly improving the maintenance convenience. Furthermore, the detector of the present embodiment adopts the modular structure described above, and when the detector needs to be upgraded and developed, the detector module can also be redesigned and developed independently, without the need to redesign and debug all other structures, thereby greatly accelerating the development speed of the system.

[0067] Reference Figure 1 The detector of the present embodiment further comprises a collimator 104 arranged below the plurality of detector units 200. The collimator 104 is used to limit the incident direction of the gamma rays, and only allows the gamma rays from a specific direction to reach the detector unit 200. By limiting the incident angle of the gamma rays, the collimator can block most of the scattered rays, reduce the interference with imaging, and improve the contrast and accuracy of the image.

[0068] Specifically, the collimator 104 comprises a plurality of small holes or slits, which function to allow only photons in a specific direction to pass through to the detector unit, thereby spatially localizing the photons.

[0069] In order to effectively ensure that only the gamma rays that pass through the collimator 104 are detected by the detector unit, in some embodiments, the detector further comprises a rack 100 and a side shield 107. The rack 100 comprises two side plates 102 respectively located at two ends in the first direction X and a support 101 arranged between the two side plates 102. The two side plates 102 and the support 101 together enclose a containing space for placing a plurality of detector units 200. The side shield 107 is arranged between the rack 100 and the detector units 200.

[0070] The rack 100 comprises two side plates 102 and a support 101, and the side shield 107 is arranged between the rack 100 and the detector units 200, that is, the side shield 107 is arranged between the two side plates 102 and the detector units 200 close to the side plates, and the side shield 107 is arranged between the support 101 and the plurality of detector units 200. In this way, gamma rays entering from the side of the detector units 200 can be shielded, thereby ensuring that only gamma rays that pass through the collimator 104 can be detected by the detector units, thereby reducing interference and optimizing imaging quality.

[0071] In some embodiments, the side shield 107 is made of tungsten or tungsten alloy. Tungsten has strong absorption and blocking ability for gamma rays, effectively reducing the entry of rays from the side of the detector units. Since tungsten has a greater density, it can provide better shielding effect at the same thickness. Or in another aspect, a thinner tungsten material can be used to achieve the same shielding effect.

[0072] In some embodiments, the side shield 107 is arranged in close contact with the inner surface of the rack 100 and the detector units. Arranging the side shield 107 in close contact between the inner surface of the rack 100 and the detector units, and in close contact with each other, can reduce the space occupied by the gap, thereby making the outer side of the detector module in the first direction X only have the shell 204, the side shield 107 and the side plates 102 of the rack 100, so that the outermost side of the probe is very close to the edge of the effective field of view area, further reducing the size of the probe dead zone.

[0073] Moreover, using tungsten material as the side shield makes the thickness of the side shield thinner, thereby further reducing the size of the probe dead zone.

[0074] Moreover, since the SiPM detector is at least 10 cm lower than the PMT detector, the side shield is also at least 10 cm lower, and the detector of the embodiments of the present disclosure is about 10 cm lower in height, and the side shield is also at least 10 cm lower in height, and the shielding material of the corresponding height is reduced, so that the weight of the detector can be further reduced. Moreover, since the weight of the SiPM detector is reduced, the load bearing requirement of the gantry is also reduced, and the gantry can be lightened.

[0075] Reference Figure 1 In some embodiments, every two adjacent detector units of the plurality of detector units are arranged in abutment. The plurality of detector units are arranged in sequence in the first direction X, and every two adjacent detector units are arranged in abutment, and the detector units at both ends in the first direction X are arranged in abutment with the side plate 102 of the gantry 100, so that the space occupied by the gap on the detection area is reduced, and the size of the probe dead zone is further reduced.

[0076] Every two adjacent detector modules of the plurality of detector modules are arranged in abutment.

[0077] In order to prevent the rays from entering the detector unit from the upper side of the detector unit, in some embodiments, referring to Figure 2 And Figure 3 The detector further comprises a back shield 106 arranged on the side of the plurality of detector units 200 away from the scintillation crystal array 211.

[0078] Reference Figure 4 And Figure 5 In some embodiments, the cover 203 is connected with the gantry 100 to hang the detector unit 200 on the gantry 100. The detector module 210 of some embodiments of the present disclosure comprises the scintillation crystal array 211 and the SiPM detector array 212, and since the SiPM detector is light in weight, the weight of the detector module 210 is also reduced, and the overall weight of the detector unit 200 is also reduced, so that the detector unit 200 can be hung on the gantry 100.

[0079] The weight of the probe of the conventional SPECT can be more than 100 kg, and due to the improvement in structure and material, the overall weight of the probe of the present disclosure is only about 50 kg, which greatly reduces the difficulty of installation and maintenance of the equipment.

[0080] As Figure 4As shown, the gantry 100 of some embodiments also includes two fixed structures 108 respectively located at both ends in the second direction Y, the fixed structures 108 are step structures and include step surfaces, and the cover 203 is overlapped on the step surfaces of the fixed structures 108 to hang the detector unit 200. Since the weight of the detector unit is relatively light, the thickness of the fixed structures 108 for bearing the detector unit 200 can be set to be relatively thin, so that the distance between the detector module inside the detector unit and the outer edge of the detector is smaller, thereby reducing the dead zone of the probe.

[0081] In some embodiments, the cover 203 has a length in the second direction Y greater than the length of the shell 204 in the second direction Y, and both ends of the cover 203 are overlapped on the gantry 100. Specifically, as shown in Figure 4 and Figure 5 As shown, both ends of the cover 203 in the second direction Y are beyond both ends of the shell 204, that is, the cover 203 has an extended end beyond the shell 204, and the extended end is overlapped on the step surfaces of the fixed structures 108. This arrangement makes the structure of the detector of the embodiments of the present disclosure compact.

[0082] As shown in Figure 5 In some embodiments, both ends of the cover 203 are provided with connecting holes 2031. The cover 203 is connected to the gantry 100 through the connecting holes 2031. The connecting holes 2031 include long holes, and the length direction of the long holes extends along the first direction X. The connecting holes 2031 are set as long holes extending along the first direction X, so that the position of each detector unit 200 relative to the gantry 100 has a certain degree of adjustment.

[0083] The weight of the detector unit 200 of the embodiments of the present disclosure is borne on the gantry 100 by the cover 203, specifically, the inner cavity of the shell 204 is placed with a plurality of detector modules 210, and the shell 204 is connected to the cover 203, and finally both ends of the cover 203 are overlapped on the fixed structures, so the cover 203 is the main part for connecting and bearing the detector unit 200, in order to improve the strength of the cover 203, the cover 203 is made of metal material.

[0084] In some embodiments, the detector also includes a collimator 104 arranged below the plurality of detector units. The collimator 104 and the detector unit are provided with a guard plate 105 therebetween.

[0085] In some embodiments, the shell 204 is made of a composite material. Specifically, the shell 204 is made of a carbon fiber material. The shell 204 is used to fix the plurality of detector modules 210 in the inner cavity of the shell 204, to shield the visible light from entering the detector modules, while as far as possible to affect the normal incidence of gamma rays, the use of carbon fiber material can meet the above requirements. Compared with the commonly used metal material plate, the attenuation of the carbon fiber material to the rays can be almost ignored.

[0086] The present disclosure provides a SPECT imaging method using the above detector, comprising the following steps:

[0087] The signal of each SiPM detector pixel 2121 corresponding channel is independently energy corrected and energy discriminated.

[0088] The signal of each SiPM detector pixel 2121 corresponding channel is independently energy corrected, so that the measurement of each detector pixel to the energy of the rays is more accurate, thereby improving the accuracy of the energy information in the image, reducing the blur and distortion of the image, improving the spatial resolution and contrast of the image, and helping to more clearly display the boundary between the diseased tissue and the normal tissue and more accurately identify the tiny lesions. Furthermore, because the SPECT imaging method of the present disclosure can independently energy correct and energy discriminate the signal of each SiPM detector pixel 2121 corresponding channel, even the signal located at the edge position can be independently energy corrected and energy discriminated, so that the uniformity of the detector can be improved.

[0089] The energy correction method refers to using a standard source, measuring the standard radioactive source with known energy, obtaining the response data of the detector to different energy photons, according to the measurement data of the standard source, using mathematical methods to fit and calibrate the energy response of the detector, through the use of polynomial fitting, linear regression and other algorithms, an accurate relationship model between the output signal of the detector and the photon energy is established, by adjusting the parameters of the model, the energy value measured by the detector is as close as possible to the actual energy value of the standard source, so as to complete the energy correction.

[0090] The energy discrimination method includes: setting an energy window, in the SPECT system, according to the photon energy range emitted by the radionuclide used, a suitable energy window is set. The energy window is a specific energy interval, only when the energy of the photon received by the detector falls within this interval, it will be recorded and used for imaging; pulse amplitude analysis, the detector converts the incident photon into an electric pulse signal, the amplitude of the pulse is proportional to the energy of the photon. By analyzing the pulse amplitude, it is determined whether the energy of the photon is within the energy window range. The circuit in the SPECT system processes the pulse signal output by the detector, measures its amplitude, and compares it with the preset energy window threshold value. If the pulse amplitude is within the energy window, the corresponding counting and data acquisition process will be triggered; if the pulse amplitude is out of the energy window range, it will not be recorded. The SPECT imaging method provided in the embodiments of the present disclosure further includes identifying true events, removing noise events, and packaging the information of the true events after independently performing energy correction and energy discrimination on the signals of each SiPM detector pixel 2121 corresponding channel, and uploading the information to the data acquisition computer.

[0091] The embodiments of the present disclosure also provide a SPECT imaging system including the detector of the above-mentioned embodiments. Moreover, the SPECT imaging system of the embodiments of the present disclosure further includes a controller configured to perform the above-mentioned SPECT imaging method.

[0092] The structure of the detector of the SPECT imaging system of one specific embodiment of the present disclosure will be described in detail below. Figures 1 to 12 The structure of the detector of the SPECT imaging system of one specific embodiment of the present disclosure will be described in detail below.

[0093] As shown in Figure 1 , the detector includes a rack 100 and a plurality of detector units 200. The rack 100 includes a support 101 and two side plates 102 respectively arranged at both ends of the support 101, and the support 101 and the two side plates 102 enclose a containing space. The plurality of detector units 200 are arranged in the containing space and arranged in sequence in the first direction X. The lower sides of the two side plates 102 are respectively provided with collimator rails 103, and the collimator 104 is installed on the collimator rails 103, and the collimator rails 103 are provided with collimator positioning and fixing devices.

[0094] The support 101 is used to support the entire detector, and the support 101 is used to fix the detector on the motion device of the SPECT imaging system so that the detector can move in multiple directions.

[0095] As shown in Figure 2 and Figure 3As shown, the probe further comprises a data processing circuit board 201 and a data transmission circuit board 202 arranged above the plurality of probe units 200. The probe units 200 detect gamma rays and convert them into electrical signals and output after preprocessing. The signals output by the probe units 200 are connected to the data processing circuit board 201 through a cable. The data processing circuit board 201 performs amplification, analog-to-digital conversion, calculation and other processing on the signals to obtain digital codes containing position information and energy information. Each probe unit 200 corresponds to one or more data processing circuit boards 201. The signals output by the data processing circuit board 201 are connected to the data transmission circuit board 202 through a cable. The data transmission circuit board 202 connects all data processing circuit boards 201 in the probe, receives the digital codes sent by the data processing circuit boards 201, and performs calculation and data packaging and other processing before sending to the data acquisition computer. It should be noted that the data processing circuit board 201 and the data transmission circuit board 202 described above are defined according to the circuit function for the convenience of description. In other embodiments, the number of circuit boards and the functional modules on each circuit board can be adjusted according to specific needs and design, and the present embodiment does not limit this.

[0096] As shown in the Figures 1 to 3 , the probe of the present embodiment is a clear stacked structure from bottom to top. The lowermost is the collimator 104, which is positioned and fixed by the collimator guide rails 103 on the left and right sides. The baffle plate 105 is arranged between the collimator 104 and the probe unit 200, and the baffle plate 105 is used for light shielding and protection of the probe unit 200. The position of the side plate 102 close to the probe unit 200 is provided with a side shield 107. The upper part of the probe unit 200 is provided with a back shield 106. The side shield 107 and the back shield 106 work together to shield the gamma rays entering from the side and the back, ensuring that only the gamma rays entering through the collimator 104 are detected.

[0097] As shown in the Figure 3 , Figure 5 , and Figure 6As shown, the detector unit 200 includes a plurality of detector modules 210, the inside of the detector module 210 is, in order from the incident direction of the rays, a scintillation crystal array 211, a SiPM detector array 212 and a preprocessing device 213, the scintillation crystal array 211, the SiPM detector array 212 and the preprocessing device 213 form the detector module 210, and are installed in the shell 204 of the detector unit 200. The shell 204 is fixed to the cover 203, forming a complete detector unit 200. The back shielding 106 and the data processing circuit board 201 are both installed on the cover 203, the cable of the output signal of the detector unit 200 passes through the cover 203 and the back shielding 106, and is connected to the data processing circuit board 201. The data transmission circuit board 202 is installed on the side plate 102 of the rack 100, and is connected to the data processing circuit board 201 and the acquisition computer through the cable respectively.

[0098] As shown in Figure 5 Each detector module 210 includes a scintillation crystal array 211, a SiPM detector array 212 and a preprocessing device 213. The working principle of the detector module 210 is that the gamma rays enter the scintillation crystal, the scintillation crystal converts the energy of the gamma rays into visible light of a specific wavelength, the visible light is transmitted along the scintillation crystal to the detection surface of the SiPM detector, the SiPM detector converts the visible light into an electrical signal, the electrical signal is processed by the preprocessing circuit board, and is transmitted to the data processing circuit board at the back end for subsequent processing. Inside the detector unit, a plurality of detector modules are placed closely to minimize the gap between the detector modules.

[0099] The scintillation crystal array 211 of the detector module of the embodiment includes a plurality of arrayed scintillation crystal blocks 2111, and the SiPM detector array 212 includes a plurality of arrayed SiPM detector pixels. The plurality of scintillation crystal blocks 2111 and the plurality of SiPM detector pixels are arranged one-to-one, so that even the rays incident from the edge of the scintillation crystal array 211 can be detected, so that the detector using the scintillation crystal array 211 and the SiPM detector array 212 in the form of the polycrystal block has almost no edge dead zone, and the effective field of view area of the detector is the same as the coverage area of the scintillation crystal array.

[0100] The detector module can also include a light guide, a light-proof layer, a shock-absorbing structure and the like.

[0101] As shown in Figure 4As shown, each detector unit 200 is arranged to extend in the second direction Y, and outside the side shield 107 on both sides of the second direction Y of the detector unit 200, a fixing structure 108 for mounting the detector unit 200 is arranged respectively, and the detector unit 200 is mounted to the fixing structure 108. That is, the detector of the embodiment includes two fixing structures 108, which are respectively located at both ends in the second direction Y, so that both ends of each detector unit 200 are mounted on the two fixing structures 108 respectively. Moreover, specifically, both ends of each detector unit 200 are overlapped on the two fixing structures 108 respectively. The data transmission circuit board 202 is mounted on the circuit board support structure 109, and the circuit board support structure 109 is mounted to the rack 100. Using the circuit board support structure 109 can reduce the deformation of the circuit board caused by plugging and unplugging the cable, thereby reducing the risk of damage to the circuit board caused by the deformation of the circuit board.

[0102] As shown in the figure, Figure 5 The detector unit 200 includes a shell 204, a cover 203, and a plurality of detector modules 210 arranged in the shell 204. The cover 203 is made of a metal material, responsible for connecting and supporting various parts of the detector unit 200. The shell 204 is made of a composite material, preferably using carbon fiber material, responsible for fixing the plurality of detector modules 210 inside the detector unit, shielding visible light from entering the detector module, while minimizing the impact on the normal entry of gamma rays. The width of the cover 203 is the same as or slightly narrower than the width of the shell 204, the length of the cover 203 exceeds the length of the shell 204, and the part of the cover 203 exceeding the shell 204 is provided with a connecting hole 2031 for fixing the detector unit 200 to the rack 100. The connecting hole 2031 is preferably designed as a long hole, specifically a waist-shaped hole, which can adjust the position of the detector unit 200 in the rack 100. The cover 203 is provided with a plurality of wire outlets 206 corresponding to the position of the connector of the preprocessing circuit board, and the cable output by the preprocessing circuit board is led out through the wire outlet and connected to the data processing circuit board. The back shield is installed on the outer surface of the cover 203, and the wire outlet is also provided at the position corresponding to the wire outlet. After the cable is installed, the wire outlet position is additionally shielded. The data processing circuit board is preferably installed on the cover 203 of the detector unit. Installing the back shield, data processing circuit board and detector unit into a whole structure can greatly improve the efficiency, reduce the difficulty and cost during production, testing, later maintenance and other work. Special auxiliary installation tools can be designed for the detector unit, which are installed on both sides of the detector unit to provide help during installation and disassembly of the detector.

[0103] The detector of the embodiment is installed first by installing all side shields 107 on the rack 100, and installing the collimator guide and the guard. Then the detector unit is installed, and the installed back shield, data processing circuit board and auxiliary installation tool of the detector unit are sequentially installed on the rack 100, the installation position of the detector unit can be fine-tuned during the installation process, and finally all screws are tightened. The circuit board support and data transmission circuit board are sequentially installed, and all cables are connected, and the installation of the core part of the detector is completed. When a specified detector unit is disassembled, the data transmission circuit board and the circuit board support are first removed, then the installation screws of the specified detector unit are loosened, the specified detector unit is removed, and if necessary during the disassembly process, the screws of the detector units on both sides of the specified detector unit can be loosened to fine-tune the position. It can be seen that the detector unit can be conveniently and independently installed and disassembled without affecting other detector units, improving the maintainability and upgradability of the system, and enhancing the economy of the SPECT system.

[0104] As shown in Figure 4 the second direction Y, the outer side of the detector unit 200 is provided with a side shield 107 and a fixing structure 108. Moreover, the thickness of the shell 204 of the detector unit 200 and the side shield is about 2 cm, and after the fixing structure 108 is installed, the distance from the outermost side of the detector to the edge of the effective field of view of the detector can reach about 3 cm, in other words, the dead zone of the present disclosure can be about 3 cm in size, compared with the detection dead zone of the conventional SPECT which is at least 6-8 cm in size. It can be seen that the structure of the present disclosure greatly reduces the probe dead zone of the detector.

[0105] The reduction of the probe dead zone has great advantages in clinical application. The advantages of the detector of the embodiment in clinical application will be described in detail below. Figures 7 to 12

[0106] In order to better illustrate the technical advantages, the application of the detector of the embodiment and the application of the detector of the related art will be compared below. The detector in the related art is based on a continuous crystal and a PMT detector, which is called a PMT detector. The detector of the embodiment is based on a scintillation crystal array and a SiPM detector array, which is called a SiPM detector.

[0107] According to the definition of the spatial resolution of the SPECT imaging system, the spatial resolution capability is inversely proportional to the distance between the scanned object and the detector, that is, the closer the scanned object is to the detector, the closer the scanning effect is to the theoretically optimal resolution capability. Therefore, in clinical application, it is most ideal to make the detector as close as possible to the scanned object to obtain better image quality and thus more accurate diagnosis.

[0108] Figure 7 ​For the position schematic diagram of using the PMT detector to perform head scan, the effective field of view area 503 of the PMT detector 402 in the related art is at least about 10 cm away from the outermost side of the detector, and the area within this distance is usually regarded as the probe dead zone 505. When performing head scan, in order to ensure that the effective field of view area 503 covers the patient's head 301, that is, the effective field of view area 503 covers the area between the top of the patient's head 301 and the chin, the PMT detector can only be placed below the scan bed, at this time the patient's head 301 is on the headrest 401 of the scan bed, and the distance L1 between the PMT detector 402 and the patient's head 301 is about the thickness of the bed plate of the scan bed plus the lifting height of the headrest, so that the distance between the detector and the patient's head is far.

[0109] Figure 8 For the position schematic diagram of using the SiPM detector of the embodiment to perform head scan, since the probe dead zone 506 of the SiPM detector is smaller, when performing head scan, the SiPM detector can be placed on the scan bed and below the headrest, at this time the effective field of view area 504 of the SiPM detector can cover the patient's head, at this time the distance L2 between the SiPM detector and the head is about the thickness of the headrest, which is much smaller than the distance L1 between the PMT detector and the head, so that the distance is reduced, so that the distance between the detector and the patient's head is closer, and thus better spatial resolution can be obtained, the image quality obtained is better, and the diagnostic accuracy is improved.

[0110] Figure 9 is a position schematic diagram of using the PMT detector to perform heart scan, Figure 10is a position schematic diagram when a heart is scanned by using the SiPM detector of the embodiment. When the heart is scanned, two detectors of the SPECT system are usually placed at 90° or 76°, and the two detectors are as close to the patient's torso 302 as possible. The angle area of the two detectors will have an area that cannot be detected due to the existence of the probe dead zone, which can be referred to as the probe angle dead zone. Since the probe dead zone 505 of the PMT detector is much larger than the probe dead zone 506 of the SiPM detector, the probe angle dead zone 508 of the PMT detector will be much larger than the probe angle dead zone 507 of the SiPM detector at the same angle. As shown in the figure, the probe angle dead zone 508 of the PMT detector will usually partially coincide with the patient's torso area, causing imaging to be missing, while the probe angle dead zone of the SiPM detector will usually not coincide with the patient's torso area, the imaging is more complete, the image effect is better, and it is more beneficial to the accuracy of clinical diagnosis. Another significant advantage of the SiPM detector 403 compared to the PMT detector 402 is that when the heart is scanned, the patient usually needs to raise both arms to make the probe closer to the body. The size of the SiPM detector in terms of probe dead zone and probe thickness is significantly smaller, and the patient's arms can be raised to a smaller extent during the scanning process, greatly improving the patient's comfort.

[0111] In particular in some embodiments, the SiPM detector of the embodiment is used to scan the heart, and radionuclide-labeled drugs are used as tracers, which can be taken up by myocardial cells. When the radionuclide decays, it emits gamma rays, which are detected by the detectors surrounding the human body. The detectors convert the gamma rays into electrical signals, which are processed by a computer and image reconstruction algorithm to obtain tomographic images of different layers of the heart, thereby showing the radioactive distribution of each part of the myocardium, indirectly reflecting the blood perfusion state of the myocardium.

[0112] The SPECT-CT system includes a SPECT imaging system and a CT imaging system, and the SPECT-CT system fuses the image data acquired by the SPECT imaging system and the image data acquired by the CT imaging system, so that the two kinds of image information can complement and accurately match each other, thereby providing more comprehensive and accurate diagnostic basis. Figure 11 is a structural schematic diagram of a SPECT-CT system using a PMT detector, Figure 12 is a structural schematic diagram of a SPECT-CT system using a SiPM detector. In the SPECT-CT system, there is an important parameter, which is the probe center distance, which refers to the distance between the center of the effective field of view FOV of the CT detector and the center of the effective field of view FOV of the SPECT detector.

[0113] Figure 11The probe center distance D1 of the SPECT-CT system using the PMT detector is shown, Figure 12 The probe center distance D2 of the SPECT-CT system using the SiPM detector is shown. When the SPECT-CT system is scanning, the effective travel distance of the scanning bed needs to cover the FOV of the SPECT and CT systems respectively. During the scanning process, the larger the sagging deformation of the scanning bed plate at the position far from the scanning bed support structure, the more difficult it is to completely solve the problem of the sagging of the scanning bed plate due to the physical principle limitation. The larger the sagging of the scanning bed plate, the greater the error when the SPECT image and the CT image are fused; the farther the scanned object is from the scanning center, the worse the image quality; at the same time, when the scanning bed deforms too much, there is also a safety hazard. Therefore, when designing the SPECT-CT system, the probe center distance is always pursued to be as small as possible. The smaller the probe center distance, the more accurate the image fusion, the better the image quality, and the shorter the effective travel distance of the scanning bed can be designed, which can greatly reduce the design difficulty and processing cost of the scanning bed. When the same CT system 406 and SPECT gantry 407 are used, the probe center distance D2 of the SPECT-CT system using the SiPM detector is significantly smaller than the probe center distance D1 of the SPECT-CT system using the PMT detector, and the difference between the two is at least the size difference between the probe dead zone 506 of the SiPM detector and the probe dead zone 505 of the PMT detector. In fact, because the SiPM detector is smaller and lighter, the motion control structure 404 of the SiPM detector can be made more lightweight and simple compared to the motion control structure 404 of the PMT detector, thereby making the probe center distance D2 of the SPECT-CT system using the SiPM detector shorter.

[0114] It can be seen that the probe dead zone of the detector of the embodiment is very small, and better imaging effect can be achieved in clinical use. In the SPECT-CT system, the probe center distance can be reduced, the image fusion error caused by the sagging of the bed plate of the scanning bed can be reduced, the travel distance of the scanning bed can be reduced, and the design difficulty of the scanning bed can be reduced.

[0115] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present disclosure but not to limit them; although the present disclosure has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present disclosure can be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the present disclosure, they should be covered in the technical solution range of the present disclosure.

Claims

1. A detector for a SPECT imaging system, characterized in that: include: A plurality of detector units (200), the plurality of detector units (200) being configured to be arranged in an array in a first direction (X); Each detector unit (200) includes a plurality of detector modules (210) arranged in a second direction (Y), the second direction (Y) being perpendicular to the first direction (X), the detector modules (210) including a scintillation crystal array (211), a SiPM detector array (212), and a pre-processing device (213) sequentially arranged in a third direction (Z), the third direction (Z), the first direction (X), and the second direction (Y) being perpendicular to each other, the scintillation crystal array (211) including a plurality of scintillation crystal blocks (2111) arranged in an array, the SiPM detector array (212) including a plurality of SiPM detector pixels (2121) arranged in an array, and the scintillation crystal blocks and the SiPM detector pixels (2121) being arranged in a one-to-one correspondence.

2. The detector according to claim 1, characterized in that The scintillation crystal block (2111) is a strip-shaped structure; and / or the scintillation crystal block (2111) is a square strip-shaped structure.

3. The detector according to claim 1, characterized in that The scintillation crystal block (2111) includes cesium iodide (CsI) scintillation crystals.

4. The detector according to claim 1, characterized in that Reflective material is provided between the plurality of scintillation crystal blocks (2111); and / or optical silicone oil is used for coupling between the scintillation crystal array (211) and the SiPM detector array (212).

5. The detector according to any one of claims 1 to 4, characterized in that The detector further comprises a frame (100) and a side shield (107); the frame (100) comprises two side plates (102) respectively located at two ends in the first direction (X) and a bracket (101) arranged between the two side plates (102); the two side plates (102) and the bracket (101) together enclose a receiving space for accommodating the plurality of detector units (200); and the side shield (107) is arranged between the frame (100) and the detector unit (200).

6. The detector according to claim 5, characterized in that: The side shield (107), the inner surface of the rack (100), and the detector unit (200) are all arranged in close contact with each other.

7. The detector according to claim 5, characterized in that The side shield (107) is made of tungsten or a tungsten alloy.

8. The detector according to any one of claims 1 to 7, characterized in that The detector further comprises a back shield (106) arranged on a side of the plurality of detector units (200) away from the scintillation crystal array (211) in the third direction (Z).

9. The detector according to any one of claims 1 to 8, characterized in that The detector includes a frame (100), the detector unit (200) further includes a shell (204) and a cover (203), the plurality of detector modules (210) are arranged in an inner cavity of the shell (204), and the cover (203) covers the opening of the shell (204) to close the shell (204).

10. The detector according to claim 9, characterized in that The cover (203) is connected to the rack (100) so that the detector unit (200) is hung on the rack (100).

11. The detector according to claim 10, characterized in that The extension length of the cover body (203) in the second direction (Y) is greater than the extension length of the shell (204) in the second direction (Y) so that both ends of the cover body (203) are overlapped on the frame (100).

12. The detector according to claim 11, characterized in that Connecting holes (2031) are provided at both ends of the cover body (203), and the cover body (203) is connected to the frame (100) through the connecting holes (2031). The connecting holes (2031) include long holes, and the length direction of the long holes extends along the first direction (X).

13. The detector according to claim 9, characterized in that The shell (204) is made of a composite material; or, the shell (204) is made of a carbon fiber material.

14. The detector according to any one of claims 1 to 13, characterized in that The detector further comprises a collimator (104) arranged on the lower side of the plurality of detector units (200), and a guard plate (105) is arranged between the collimator (104) and the plurality of detector units (200).

15. The detector according to any one of claims 1 to 14, characterized in that Every two adjacent detector units in the plurality of detector units (200) are arranged in close contact with each other; and / or every two adjacent detector modules in the plurality of detector modules (210) are arranged in close contact with each other.

16. A SPECT imaging system, characterized in that: include: A detector as claimed in any one of claims 1 to 15.

17. A SPECT imaging method comprising: Detection is performed using the detector according to any one of claims 1 to 16 or the SPECT imaging system according to claim 16, comprising the following steps: Independent energy correction and energy discrimination are performed on the signal of the corresponding channel of each SiPM detector pixel (2121).

Images