Tapered scintillator crystal module and method of using same

Abstract

Provided are tapered scintillator modules and detection apparatuses having tapered scintillator modules that taper at least at the end that contacts the optical sensor, where the tapering depends on the location of the scintillator module within the active area of the optical sensor. The tapering of the scintillator module can be close to the interface between the optical sensor and the module to minimize light leakage at the interface to neighboring pixels, while still allowing the detection apparatus to maintain high geometric efficiency and sensitivity to incident gamma rays, since the distal end can not taper, which has the highest likelihood of gamma ray interactions based on the Beer-Lambert law of photoabsorption.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application Serial No. 63 / 073,785, filed September 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates generally to the field of radiation imaging, and more particularly to positron emission tomography (PET). Background Technology

[0004] PET imaging is a powerful technique primarily used for the diagnosis, treatment selection, treatment monitoring, and research of cancer and neuropsychiatric disorders. Despite its high molecular specificity, quantitative properties, and clinical usability, PET has not yet reached its full potential as a reliable molecular imaging modality, mainly due to its relatively poor spatial resolution. At this spatial resolution, current devices cannot measure the target density in many human and rodent brain regions, as well as in small nodules, that are relevant to disease etiology and pathophysiology.

[0005] Detector systems for PET require thick, high-density scintillator crystal modules to efficiently detect the high-energy (511 keV) gamma rays used in PET. High geometric efficiency (e.g., minimal gaps or spacing between scintillator crystal modules) is also crucial for achieving high gamma-ray detection sensitivity (and improving spatial resolution) in PET.

[0006] Depth-encoded PET detector modules have been developed to mitigate parallax errors (mislocalization of response lines) in long scintillator crystals. This allows for reduced component costs per detector ring in small-diameter PET rings, large solid-angle coverage for increased sensitivity, and a reduction in spatial resolution due to annihilation gamma-ray collinearity when using crystals with small cross-sectional areas. Furthermore, depth of interaction (DOI) information can be used to deconvolve photon transport in long crystals, thereby improving the uniformity of temporal and spatial resolution. Additionally, known PET systems possess time-of-flight (TOF) readout capabilities, which improve signal-to-noise ratio (SNR) and sensitivity by accurately estimating the gamma-ray source location.

[0007] However, in one or more known DOI-PET detector modules, such as those with light guides coupled to the far end of the scintillator module (away from the optical sensor), there is a trade-off between the spacing (gap) between the scintillator modules and DOI / TOF performance. This is because most photons interact with the sensor array from the edges of the scintillator modules. Reducing the spacing (gap) between adjacent scintillator modules increases light leakage to neighboring pixels, which can degrade both TOF and DOI performance. Notably, TOF may be correlated with DOI. However, optical photon leakage to pixels adjacent to the main pixel (light leakage) caused by incomplete coupling weakens this correlation.

[0008] Furthermore, the overlap between a portion of the scintillator module and the gap (pixel gap) between the optical sensor can lead to signal loss along the edges. Summary of the Invention

[0009] Therefore, a particle detection device is disclosed, which may include an array of optical sensors arranged in a two-dimensional array and a plurality of scintillator modules. A first gap may exist between adjacent optical sensors. Each optical sensor may correspond to one pixel. Each optical sensor may have an effective area. At least one scintillator module may correspond to a corresponding optical sensor in the array. Each scintillator module may have a first end and a second end. The first end may contact the corresponding optical sensor. A second gap may exist between adjacent scintillator modules. The second gap is defined as the minimum gap between adjacent scintillator modules. A scintillator module adjacent to the boundary of the effective area of ​​the corresponding optical sensor may have a tapered portion at its first end such that, when viewed along the longitudinal axis, a first cross-sectional area of ​​the first end overlaps with the effective area. The first cross-sectional area is defined as perpendicular to the longitudinal axis. The second gap may be smaller than the first gap.

[0010] In one aspect of this disclosure, the second cross-sectional area at the second end may be larger than the first cross-sectional area. The second cross-sectional area is defined as perpendicular to the longitudinal axis. In another aspect of this disclosure, when viewed along the longitudinal axis, at least a portion of the second cross-sectional area at the second end may overlap with the first gap.

[0011] In one aspect of this disclosure, the shape of the first cross-sectional area may be approximately circular.

[0012] In one aspect of this disclosure, a one-to-one correspondence (one-to-one coupling) may exist between the scintillator module and the optical sensor. The first cross-sectional area may be rectangular, and all four sides at the first end may taper.

[0013] In other aspects of this disclosure, there may be a four-to-one correspondence (four-to-one coupling) between the scintillator module and the optical sensor. In one aspect of this disclosure, the first cross-sectional area of ​​each scintillator module may be defined by a plurality of sides, and at least two sides of the scintillator module facing the respective boundary of the effective area may taper at a first end. In other aspects, only the sides of the scintillator module facing the respective boundary of the effective area may taper at the first end.

[0014] In one aspect of this disclosure, the tapered portion may have a tapered length in a direction parallel to the longitudinal axis, and said tapered length may be less than one-third of the length from the first end and the second end in the direction parallel to the longitudinal axis. For each scintillator module having a tapered portion, the tapered length may be the same.

[0015] In one aspect of this disclosure, the scintillator module may be approximately 20 mm long in the longitudinal direction. In this aspect, the tapered length may be approximately 5 mm.

[0016] In one aspect of this disclosure, the second cross-sectional area may be about 1.5 mm x about 1.5 mm, and the first cross-sectional area may be about 1.4 mm x about 1.4 mm. The effective area may be about 3.0 mm x 3.0 mm.

[0017] In one aspect of this disclosure, the device may further include a light guide. The light guide may be segmented. In one aspect of this disclosure, the segmented light guide may include a plurality of prismatoids. Each prismatoid may be configured to redirect radiated particles between the second ends of the scintillator modules. In one aspect of this disclosure, the segments of the light guide may be offset from the optical sensors such that a first scintillator module in contact with a first optical sensor and a second scintillator module in contact with a second optical sensor are in contact with the same segment.

[0018] In one aspect of this disclosure, the device may further include a reflector. In another aspect, the reflector may be located on the light guide. In yet another aspect, the reflector may be located between segments of the light guide. In yet another aspect, the reflector may be located between each scintillator module and another scintillator module, included in the gap between the tapered portions.

[0019] In one aspect of this disclosure, the second end of certain scintillator modules may have a second tapered portion. The longitudinal length of the second tapered portion may be less than the longitudinal length of the tapered portion.

[0020] In one aspect of this disclosure, because the segment is offset from the optical sensor, the side of the scintillator module that can taper at the second end may be different from the side of the scintillator module that can taper at the first end.

[0021] A particle detection device is also disclosed, which may include an array of optical sensors arranged in a two-dimensional array and a plurality of scintillator modules corresponding to the respective optical sensors. A first gap may exist between adjacent optical sensors. Each optical sensor may correspond to one pixel. Each optical sensor may have an effective area. Each scintillator module may have a first end and a second end. The first end may contact its corresponding optical sensor. A second gap may exist between adjacent scintillator modules. The second gap is defined as the minimum gap between adjacent scintillator modules. At least a subset of the plurality of scintillator modules corresponding to the respective optical sensors may have a tapered portion at the first end. The position of the tapered portion may depend on the relative position of the scintillator modules within the effective area and the corresponding boundary of the effective area. The second gap may be smaller than the first gap.

[0022] In one aspect of this disclosure, the device may further include a reflector located between each scintillator module and another scintillator module in the gap included between the tapered portions.

[0023] In one aspect of this disclosure, a scintillator module located at a corner of the effective area may have at least two sides tapering at a first end such that a first cross-sectional area at the first end overlaps with the effective area when viewed along the longitudinal axis. The first cross-sectional area is defined as perpendicular to the longitudinal axis. In other aspects, only the two sides of the scintillator module located at a corner of the effective area tapere at the first end.

[0024] In one aspect of this disclosure, a scintillator module located at a corner of the effective area and aligned with other scintillator modules may have only one side tapering at a first end, such that when viewed along the longitudinal axis, a first cross-sectional area of ​​the first end overlaps with the effective area. This one side may face the boundary of the effective area.

[0025] In one aspect of this disclosure, a scintillator module located between the scintillator module and the boundary of the effective area may not have a tapered portion at its first end. Attached Figure Description

[0026] The documents of this patent contain at least one color drawing. A copy of this patent with (one or more) color drawings will be provided by the Patent and Trademark Office upon request and at the cost of payment.

[0027] Figure 1 A cross-sectional view of a particle detection apparatus according to an aspect of this disclosure is shown, wherein there is a four-to-one coupling from a scintillator module to an optical sensor;

[0028] Figure 2A view of an optical sensor according to an aspect of this disclosure is shown, with a tapered end (first end) and a non-tapered end (second end) of a scintillator module shown relative to the optical sensor, wherein there is a four-to-one coupling between the scintillator module and the optical sensor;

[0029] Figure 3 A view of the sensor array and scintillator module is shown, showing the tapered and non-tapered walls (partial) of the scintillator module, where there are four-to-one couplings from the scintillator module to the optical sensor;

[0030] Figure 4 A side-by-side view of the non-tapered end (second end) and tapered end (first end) of the scintillator module is shown;

[0031] Figures 5A and 5B show side-by-side views comparing leaks in known particle detection devices with those in particle detection devices according to aspects of this disclosure;

[0032] Figure 6 A cross-sectional view of a particle detection apparatus according to other aspects of this disclosure is shown, wherein a one-to-one coupling exists between a scintillator module and an optical sensor;

[0033] Figure 7 A view of the sensor array and scintillator module is shown, showing the tapered and non-tapered walls (partial) of the scintillator module, where there is a one-to-one coupling between the scintillator module and the optical sensor;

[0034] Figure 8 A cross-sectional view of a particle detection apparatus according to other aspects of this disclosure is shown, wherein there is a nine-to-one coupling from a scintillator module to an optical sensor;

[0035] Figure 9 A view of the sensor array and scintillator module is shown, which tapers based on its relative position within the effective area, with nine-to-one coupling between the scintillator module and the optical sensor.

[0036] Figure 10 A cross-sectional view of a particle detection apparatus according to other aspects of the present disclosure is shown, wherein, according to aspects of the present disclosure, the first and second ends of certain scintillator modules taper.

[0037] Figures 11 to 15 Different views of a scintillator module with a tapered first end, manufactured according to aspects of this disclosure, are shown, wherein there is a four-to-one coupling between the scintillator module and an optical sensor, wherein Figure 14 and 15 The sensor array is also shown;

[0038] Figure 16 and 17Different views of other scintillator modules manufactured according to aspects of this disclosure are shown, some of which taper at a first and second end, wherein the tapered sides (partially) are different at the first and second ends, and wherein there is a four-to-one coupling between the scintillator module and the optical sensor. Figure 17 The sensor array is also shown;

[0039] Figure 18 A graph is shown illustrating the correlation between the interaction depth and time of flight for two different timestamping methods; and

[0040] Figures 19A to 19C A graph is shown illustrating the three calculated parameters of the interaction depth, where Figure 19A Energy-based DOIs are shown. Figure 19B It shows the time based on using a timestamp, and Figure 19C The time is shown based on the average of three timestamps. Detailed Implementation

[0041] According to aspects of this disclosure, the ends of certain scintillator modules closest to the optical sensor 120 taper, thereby reducing unwanted photon (light) leakage to adjacent or neighboring pixels (different optical sensors). According to aspects of this disclosure, when viewed longitudinally, the ends of these scintillator modules closest to the optical sensor will not intersect with sensor G. D The overlapping gaps between modules reduce signal loss along the edges. Simultaneously, geometric efficiency (the gap between adjacent modules, determined by the minimum gap between adjacent modules) is maintained, enabling high gamma-ray detection sensitivity. Since the distal end of the scintillator module does not taper, it can have a full width, and efficiency is maintained due to the highest probability of gamma-ray interaction at the distal end based on the Beer-Lambert law of photoelectric absorption.

[0042] According to aspects of this disclosure, the scintillator modules can be arranged in different configurations. For example, Figure 1 An example of the scintillator module arrangement is shown. Figure 1 In this configuration, for each optical sensor 120, there are four scintillator modules 100, although Figure 1 This is a cross-sectional view showing only the two scintillator modules for each optical sensor 120. Figure 2 and Figure 3 Four scintillator modules are shown in the figure.

[0043] Each scintillator module 100 may be made of yttrium lutetium silicate (LYSO) crystal. The scintillator module 100 is not limited to LYSO, and other types of crystals that emit photons in the presence of incident gamma radiation, such as lutetium silicate (LSO), may be used. One end of the scintillator module 100 may be in contact with the optical sensor 120 (first end 107).

[0044] In one aspect of this disclosure, the optical sensor 120 may be a silicon photomultiplier (SiPM). In other aspects of this disclosure, the optical sensor 120 may be an avalanche photodiode (APD), a single-photon avalanche (SPAD), a photomultiplier tube (PMT), or a silicon avalanche photodiode (SiAPD). These are non-limiting examples of solid-state detectors that can be used. Although in Figure 1 In the diagram, the optical sensor 120 is shown as separate, but the optical sensor 120 can be manufactured in a single package or board with gaps (effective area 300) between the sensors. Figure 14 and 15 An example of a package or board (sensor array 300) is shown. The number of optical sensors 120 (pixels) in device 1 can be based on the application and size of the PET system. In one aspect of this disclosure, the optical sensors 120 can be arranged as a two-dimensional array, such as an 8x8 array. The two-dimensional array is formed in a plane perpendicular to the longitudinal axis of the scintillator module. Figure 1 The direction of the vertical axis is shown in the diagram. For descriptive purposes, the vertical axis is the z-direction, and the two-dimensional array is the xy-direction. The optical sensors 120 are arranged in an array such that there is a sensor gap G. D 117 (in) Figure 1 (Indicated by a double-ended arrow). Figure 1 The four dots indicate other sensors / modules in the array that are not specifically shown in this view.

[0045] In the case of an 8x8 array, the scintillator module 100 is configured as a 16x16 array (to achieve four-to-one coupling between the module 100 and the optical sensor 120). The scintillator module 100 is arranged with a module gap G. S 119. The module gap G referred to here S The minimum distance (non-tapered portion) between adjacent or neighboring scintillator modules in the x or y direction is defined. Module gap G S Example 119 in Figure 1 It is indicated by a double-ended arrow.

[0046] According to aspects of this disclosure, the module gap G S 119 < Sensor gap G D 117, which enables the detection device 1 to have high gamma-ray detection sensitivity. Therefore, there exists... Figure 1 The overlapping area 121 shown, the gap G between the scintillator module 100 and the sensor. D The two lines overlap here (viewed vertically). The overlapping area 121 is shown between the two dashed lines.

[0047] The second end 109 of the scintillator module 100 (relative to the distal end of the optical sensor 120) contacts the light guide 110. The light guide 110 can be any light guide, such as a single uniform waveguide. The light guide 100 is configured for inter-crystal light sharing between scintillator modules 100, including between modules 100 with different pixels or between modules 100 associated with different optical sensors 120.

[0048] In other aspects, the optical guide 110 can be as follows: Figure 5B The segmented light guide 110A is shown. Each segment is configured to redirect particles between certain scintillator modules. An example of a segmented light guide is described in U.S. Patent Publication No. 2020 / 0326434, the disclosure of which is incorporated herein by reference. The position of each segment (in the x-direction or y-direction) is offset from the optical sensor 120. Figure 5B As shown, one segment of the light guide contacts a scintillator module associated with a first optical sensor (e.g., sensor 1) and another scintillator module associated with a second optical sensor (e.g., sensor 2), allowing light to be shared between adjacent pixels. In one aspect of this disclosure, each segment couples only scintillator modules belonging to different optical sensors (pixels).

[0049] Each segment of the optical guide 110A may include a pseudo-prism. In one aspect of this disclosure, the shape of the pseudo-prism may be approximately at least one of the following: at least one prism, at least one antiprism, at least one truncated pyramid, at least one triangle, at least one dome, at least one parallelepiped, at least one wedge, at least one pyramid, at least one truncated pyramid, at least a portion of a sphere, at least one cuboid, and at least one pyramid.

[0050] The use of segments increases the light sharing rate between crystals, thereby improving crystal recognition and DOI resolution. In some aspects of this disclosure, depending on the location of the segments within the scintillator array, different designs of pseudo-pillars can be used. For example, there may be three different designs: corner pseudo-pillars, center pseudo-pillars, and edge pseudo-pillars, wherein the corner and edge pseudo-pillars are designed to mitigate edge and corner artifacts.

[0051] Some scintillator modules 100 have a tapered portion 105. In one aspect of this disclosure, the tapered portion 105 is located at a first end 107. For example... Figure 1As shown, the walls of the scintillator module 100 are inclined inward. A virtual line extending parallel to the longitudinal axis and along (also parallel to the longitudinal axis) the walls or surface of the scintillator module defines an angle A (acute angle) with the tapered wall. In one aspect of this disclosure, the tapering causes the first end 107 (contact end) to not contact the sensor gap G. D Overlap (in other words, the first end only overlaps with the effective area of ​​sensor 120). Although Figure 1 The tapered wall (the wall between the tapering start and the sensor surface) is shown to be straight (straight profile), but in other respects, the wall can be curved (curved profile). This is because the first end 107 overlaps only with the effective area 310 of the optical sensor 120, and not with the gap G between the sensors. D The overlap reduces signal loss along the edges due to photon leakage.

[0052] In one aspect of this disclosure, angle A is selected to ensure that the first end 107 does not intersect with the sensor gap G. D The angle A overlaps, but at the same time it is not so steep that the photon is reflected away from the surface of the tapered wall and remains within the scintillator module 100 (and is not detected).

[0053] In another aspect of this disclosure, the starting point of the taper can be chosen to maintain high sensitivity. For example, if the taper begins near the second end 109 and tapers gradually all the way to the first end 107, the sensitivity will decrease because the overlap area 121 will be small, and as mentioned above, most photons interacting with the sensor array originate from the edges of the scintillator modules. Starting the taper near the second end 109 increases the distance between adjacent scintillator modules over a longer length along the longitudinal axis. In some aspects of this disclosure, the taper can begin closer to the first end 107 than the second end 109. For example, the taper can begin less than halfway between the first end 107 and the second end 109. In other aspects of this disclosure, the taper can begin at approximately one-third of the distance between the first end 107 and the second end 109 (closer to the first end 107).

[0054] like Figure 1As shown, device 1 may also include a reflector 115. Reflector 115 may include barium sulfate (BaSO4). In other aspects, reflector 115 may include other reflective materials. In one aspect of this disclosure, reflector 115A may be used between each scintillator module 100. Furthermore, in one aspect of this disclosure, the gaps created by the tapered portion 105 may also be filled with reflector 115A. In the figures, to emphasize that the gaps created by the tapered portion may also be filled with reflectors, reflectors 115A in these gaps are shown with a different hashing than reflectors 115A in the gaps (119) between scintillator modules. Reflector 115A may be made of the same material as reflector 115, such as, but not limited to, barium sulfate (BaSO4). This material has high spatial performance and does not reduce energy and temporal resolution. When using segmented light guides 110A, reflector 115 may also fill any gaps between segments of segmented light guides 110A.

[0055] Figure 2 The relationship between the first end (first end 107, which tapers) and the second end (second end 109, which may not taper) of the scintillator module and the optical sensor 120 is shown. Figure 2 As shown, the second end 109 has a portion that does not overlap with the sensor 120 (effective area), while the first end 107 (tapered) overlaps with the sensor 120 and does not have a portion that does not overlap with the sensor 120.

[0056] In one aspect of this disclosure, the wall of the scintillator module 100 facing the boundary or edge of the optical sensor 120 may taper. Figure 3 An example of sensor array 300 is shown. Four dots represent other sensor / scintillator modules in the array (four sensors are shown specifically for illustration purposes). Each sensor 120 has an effective area 310 (defining one pixel). Each effective area has four edges defined by edges or boundaries. Figure 3 As shown, the walls (boundary walls 305) of the scintillator module facing the boundary or edge of the effective area can taper. These walls are... Figure 3 The image is shown in dashed lines. On the other hand, the walls (inner walls) of scintillator modules that do not face the boundaries or edges of the effective area may not taper (non-tapered wall 315) to maintain high gamma-ray detection sensitivity.

[0057] Figure 4An example of the relative dimensions of the tapered end (first end 107) and the non-tapered end (second end 109) is shown side-by-side. The first end 107 has a first cross-sectional area 400, and the second end 109 has a second cross-sectional area 405. The first cross-sectional area 400 and the second cross-sectional area 405 are areas perpendicular to the longitudinal axis (e.g., areas in the xy plane). The first cross-sectional area 400 is the area in contact with the optical sensor 120. The second cross-sectional area 405 is the area in contact with the light guide 110 / 110A.

[0058] like Figure 4 As shown, the sensor array 300 is 8x8 (as described above) and has four-to-one coupling (therefore, there is a 16x16 scintillator module array). From Figure 4 As can be seen, the gap 410 between scintillator modules associated with different optical sensors is greater than the gap G between scintillator modules. S 119. The gap 410 can be greater than or equal to the sensor gap G. D 117. In other words, the first cross-sectional area 400 does not need to reach the boundary of the effective area 310 (pixels). The spacing between the scintillator modules 100 within group 415 (at the first end) is smaller than the spacing between groups (between groups 415) (gap 410). Figure 4 As shown, there are four scintillator modules 100 in group 415, for example, four-to-one coupled.

[0059] Figures 2 to 4 A first end (first cross-sectional area 400) with a generally rectangular shape is shown. However, in other aspects of this disclosure, the first cross-sectional area may have other shapes. The shape can be determined according to the manufacturing process and tolerances. For example, the shape may be generally circular. For example, the tapered portion 105 may appear conical.

[0060] When the shape is circular, the tapered portion 105 may correspond only to the portion facing the boundary or edge of the effective area, such as a semicircle. The shape may be square, Luro triangle, spherical triangle, hexagon, pentagon, octagon, etc.

[0061] Figure 5A and Figure 5B A portion of a detection device with a non-tapered scintillator module 100A and a detection device according to an aspect of the present disclosure having a scintillator module 100 in which some modules have tapered portions 105 are shown. As shown in FIG5A, light leakage and reduced sensitivity may occur because the first end extends beyond the optical sensor (overlapping with the gap between the sensors). In contrast, according to an aspect of the present disclosure, the first end 107 tapers (having tapered portions 105), wherein the first end 107 does not extend to the gap G. DIt does not extend beyond the effective area 310 of the optical sensor 120, thus reducing unwanted leakage, such as minimizing unwanted leakage, and in some cases, any leakage may be below the background noise level and therefore may not be detectable.

[0062] The detection device 1 can have other configurations (besides four-to-one coupling). For example, the detection device 1A can have, for instance, a four-to-one coupling. Figure 6 and Figure 7 The diagram shows a one-to-one coupling configuration. The scintillator module 100B and the optical sensor 120 are arranged in a two-dimensional array. The scintillator module 100B has a scintillator module gap G. S 119A. The size of the gap may differ from the gap size in a four-to-one coupling configuration. The scintillator module 100B serves as an overlapping area 121A, in which, when viewed along the longitudinal axis, the scintillator module 100B and the sensor gap / spacing G... D 117 overlaps. In Figure 6 For descriptive purposes, two sensors 120 (e.g., sensor 1 and sensor 2) are shown, and other sensors are represented by four dots.

[0063] The scintillator module 100B may have a tapered portion 105A at the first end 107A. Since there is only one scintillator module 100B for each optical sensor 120 in this configuration, all walls (sides) of the scintillator module 100B extending in the longitudinal direction (z direction) are boundary walls (boundaries or edges near the effective area), and therefore all walls can be tapered. Figure 7 An example of a sensor array 300 is shown, with four sensors specifically illustrated for illustrative purposes. Other sensors in the array are represented by four dots. Figure 7 In the middle, the gradually narrowing boundary wall 305 is marked with a dashed line.

[0064] Although Figure 7 Four tapered walls are shown, but in other aspects of this disclosure, fewer than four walls may be tapered. For example, in the case where the optical sensor is located at a corner of the sensor array, walls (sides) not adjacent to other sensors 120 may not be tapered.

[0065] Figure 8 and Figure 9 A representation of another detection device 1B according to an aspect of this disclosure is shown. Detection device 1B has a nine-to-one coupling configuration. Nine scintillator modules 100 correspond to one sensor 120. Figure 8 For descriptive purposes, two sensors 120 (e.g., sensor 1 and sensor 2) are shown, and other sensors are represented by four dots.

[0066] The scintillator modules 100 / 100A and the optical sensor 120 are arranged in a two-dimensional array. The scintillator modules 100 / 100A have scintillator module gaps G. S 119B. The size of this gap can differ from the gap size in a four-to-one coupling configuration or a one-to-one coupling configuration. The scintillator module 100 has an overlap area 121B in which, when viewed in the longitudinal direction, the gap G between the scintillator module and the sensor is [missing information]. D 117 overlaps.

[0067] According to an aspect of this disclosure, certain scintillator modules may taper at a first end 107B. The taper may be based on the relative position of the scintillator module with respect to the effective area 310, for example, adjacency to a boundary or edge of the effective area 310. If the scintillator module 100A is not adjacent to a boundary or edge of the effective area 310, the scintillator module 100A may not taper. However, if the scintillator module 100A is located near a boundary or edge of the effective area 310, one or more walls of the scintillator module 100 may taper. In one aspect of this disclosure, a taper portion 105B may be present at the first end 107B. Similar to the above, the taper ensures that there is no sensor gap G at the first end 107B. D 117 Overlapping area or portion (even at the distal end of the tapering portion 105B, there may be an overlapping area 121B).

[0068] In one aspect of this disclosure, the number of tapered walls can also depend on the position of the scintillator module 100 relative to the effective area 310. For example, as Figure 9 As shown, the scintillator module 100 located at the corner of the effective area 310 can have two tapered walls (two boundary walls 305). The boundary walls 305 are... Figure 9 The scintillator module 100 is shown in dashed lines. In other respects, where the scintillator module 100 is not at a corner but is still adjacent to the boundary or edge of the effective area 310, the scintillator module 100 may have only one wall taper (e.g., a wall facing the boundary or edge). In other respects, other walls (non-boundary walls) may taper as needed.

[0069] exist Figure 9 In the example shown, four scintillator modules 100 have two wall tapers (corner modules), four scintillator modules 100 have one wall taper (scintillator modules between corner modules), and one scintillator module 100A does not taper.

[0070] exist Figure 9 In the example shown, four optical sensors 120 are specifically depicted in the array, while other optical sensors are represented by dots.

[0071] According to aspects of this disclosure, other scintillator module 100 / sensor 120 configurations can be used, such as 16-to-1 coupling or asymmetric coupling, such as 2x1, etc.

[0072] In one aspect of this disclosure, where multiple walls (sides) of the scintillator module 100 taper, the taper amount can be substantially the same to provide symmetry. However, when the scintillator module 100 is manufactured with tapered walls (sides), tolerances may exist in the taper amount due to limitations in the manufacturing process. The term "substantially the same" as used herein also includes dimensional differences due to manufacturing and tolerances.

[0073] The use of the phrase "(one or more) sides" or "(one or more) walls" to taper can also refer to tapering of (one or more) portions or surfaces of the scintillator module 100. For example, in the case where the scintillator module is cylindrical and has curved surfaces only in the longitudinal direction (z direction), a portion of the scintillator module 100 may taper (the portion facing the boundary or edge of the effective area).

[0074] Figure 10 A cross-sectional view representing a particle detection apparatus 1D according to other aspects of this disclosure is shown. According to this aspect of the disclosure, for some scintillator modules 100C, both the first end 107 and the second end 109A may have tapered portions (e.g., a first tapered portion 1005 and a second tapered portion 1000). The tapering of the first end 107 has already been described above and will not be described in detail again.

[0075] In this aspect of the disclosure, the second end 109A may be tapered to reduce signal loss along the edge due to misalignment of the segmented light guide 110A and the scintillator module 100C. Slight misalignment may be a legacy issue from the manufacturing process, during which perfect alignment (the edge of the scintillator module perfectly coinciding with or aligning with the edge of the light guide segment) rarely occurs. When misalignment is present and a portion of the second end of the scintillator module extends beyond the segment of the segmented light guide 110A, photons may be lost (not reflected). As mentioned above, since most photons interacting with the optical sensor originate from the edge of the scintillator module, photon loss from the edge degrades the performance of the PET. By tapering the second end 109A and having a second tapered portion 1000 such that the second end 109A does not extend beyond the segment, any edge loss due to misalignment of the segmented light guide 110A and the scintillator module 100C is reduced.

[0076] Typically, the misalignment between the segmented light guide 110A and the scintillator module 100C can be very small, for example, less than 1 mm. The taper angle B is defined as the angle (acute angle) between a virtual line extending parallel to the vertical axis and along (also parallel to the vertical axis) the wall or surface of the scintillator module and the taper wall. Similarly, the taper start point can also be close to the second end 109A. Furthermore, since the taper at the second end 109A is not designed to address undesirable leakage between scintillator modules associated with different sensors 120 or pixels, the length of the second taper portion 1000 can be shorter than the length of the first taper portion 1005. Because the length of the second taper portion 1000 can be shorter than the length of the first taper portion 1005, the taper angle B of the second taper portion 1000 can be greater than the taper angle A of the first taper portion 1005.

[0077] Although the same scintillator module 100C can taper at the first end 107 and the second end 109A, the tapered portion or wall is offset. For example, as Figure 10 As shown, the scintillator module 100C tapers at a first end (first taper portion 1005) on a wall or portion facing the boundary or edge of the effective area 310. However, since the segments of the segmented light guide 110A are offset from the sensor 120 and contact the scintillator modules in different (adjacent or neighboring) pixels, the wall or portion tapering at the second end 109A (second taper 1000) is a wall or portion not facing the boundary or edge of the effective area 310 (e.g., an inward wall or portion).

[0078] Figures 11 to 15 Different views of a scintillator module with a tapered first end 107, manufactured according to aspects of this disclosure, are shown, wherein there is a four-to-one coupling between the scintillator module and an optical sensor. Figure 11 and 12 The image shows a scintillator module, but not a light guide or optical sensor (or reflector). Figure 11 and 12 As shown, the scintillator modules 100 are arranged in a 16x16 array (LYSO crystals). Each scintillator module 100 is designed to be approximately 20 mm in the longitudinal direction (z-direction). The second end 109 is designed to have a second cross-sectional area of ​​approximately 1.5 mm x approximately 1.5 mm. The scintillator module 100 generally has this cross-sectional area until the taper begins. The taper is designed to begin approximately 5 mm from the first end (the interface between the scintillator module and the optical sensor). The first cross-sectional area is designed to be approximately 1.4 x approximately 1.4 mm to minimize the gap G. D Any overlap of 119, and keeping the first end 107 within the effective area 310. Tapering occurs only on walls or portions of the boundary or edge facing the effective area 310. Scintillator module gap G between adjacent scintillator modules. S117 is approximately 0.1 mm.

[0079] like Figure 13 As shown, the second end 109 is in contact with the segmented light guide 110A. In this case, the segmented light guide is a quasi-cylindrical light guide array (at the radiation receiving end). The reflector 115 is located on top of the segmented light guide 110A.

[0080] Figure 14 A scintillator module 100 is shown before being mounted to an optical sensor. From Figure 14 As can be seen, the gap between the scintillator modules associated with different pixels (sensors) at the first end 107 is larger than that of the scintillator module G. S 117.

[0081] The optical sensor gap is approximately 0.2 mm. The effective area is approximately 3.00 mm x approximately 3.00 mm. The pixel pitch is approximately 3.2 x 3.2 mm.

[0082] Figure 15 A scintillator module 100 is shown in contact with an optical sensor array 300. The optical sensor array 300 is electrically coupled to a connector 1500. This connector 1500 is electrically coupled to a processor ( Figure 15 (Not shown in the image). The processor is configured for DOI and TOF analysis. The processor executes one or more programs to determine the DOI and TOF.

[0083] Figure 16 and Figure 17 This is a different view of a scintillator module having a tapered first end 107 and a tapered second end 109A manufactured according to aspects of this disclosure, wherein there is a four-to-one coupling between the scintillator module and an optical sensor. Figure 16 and 17 As shown, the flashing module 100C has a first tapered portion 1005 and a second tapered portion 1000. The length of the second tapered portion 1000 in the vertical direction is less than the length of the first tapered portion 1005 in the vertical direction. Furthermore, as... Figure 16 and 17 As shown, the tapered walls or portions of the first tapered portion 1005 and the second tapered portion 1000 are different (offset). The second cross-sectional area is designed to be approximately 1.35mm x 1.35mm. Figure 16 and 17 A reflector 115B is also shown enclosing the scintillator module 100 to prevent light leakage from corner and edge pixels. For illustrative purposes, the reflector 115B is shown only around a portion (center) of the scintillator module 100 so that the module is visible. However, in operation, the reflector 115B will extend the entire longitudinal length of the scintillator module (edge ​​and corner modules).

[0084] As described herein, tapering the first end 107 of the scintillator module 100 improves the correlation between TOF and DOI. A scintillator module array is fabricated as described herein to determine the correlation between TOF and DOI. Depth calibration data (floodlight histograms) are acquired at 1 mm steps at 19 different depths (1 mm to 19 mm). A four-to-one coupling from the scintillator module to the optical sensor is used. A 3 MBq Na-22 point source (1 mm effective diameter) is placed in a lead cylinder with a 1 μm diameter pinhole and positioned between the detection device as described herein and a reference scintillator array without tapering. The reference scintillator array has a four-to-one coupling with a SiPM. The scintillator module has dimensions of approximately 1.4 mm x approximately 1.4 mm x approximately 20 mm. Both use the same SiPM. As described above, both sides are tapered (boundary walls).

[0085] Barium sulfate (BaSO4) is used to fill intercrystalline voids and acts as a diffuse reflector in crystal arrays and light guides. All crystals are fully polished, and the modules are wrapped with black tape.

[0086] Light leakage at the interface is random, while the shared light within the segmented light guide (quasi-cylinder) is deterministic.

[0087] Only coincidence events between the detection device and the reference according to this disclosure were used for data analysis to exclude Compton scattering. For example, only events where the highest signal was more than twice the second highest signal were accepted. 10,000,000 events distributed across all scintillator modules were collected and used for analysis. Peak filtering was performed based on each scintillator module with a 15% energy window.

[0088] For each event, three different estimation parameters were used, one based on energy and two based on time, to explore the correlation between DOI and TOF.

[0089] For energy-based DOI (w E Use an energy-weighted average method. Calculate using the following equation:

[0090]

[0091] Among them, w E These are energy-weighted DOI parameters, P m It is the maximum energy absorbed on a single SiPM pixel, and P is the sum of all energies across all pixels.

[0092] Time-based DOI (w TOF ) Calculated in the following two different ways

[0093] w TOF1 =tn1 -t p (2)

[0094] Among them, w TOF1 It is a TOF-weighted DOI parameter using a single timestamp, t n1 It is the first timestamp from the adjacent pixel to the main pixel, and t p It is the timestamp from the master pixel (i.e., the master timestamp). An adjacent pixel is one of the nearest pixels coupled to the same light guide segment (the same pseudo-cylindrical light guide).

[0095]

[0096] Among them, w TOF3 It is a TOF-weighted DOI parameter with 3 timestamps, t n1 t n2 and t n3 It consists of the first, second, and third timestamps from adjacent pixels, and t p This is the master timestamp. These three adjacent pixels are the nearest pixels coupled to the same light guide segment (the same pseudo-cylindrical light guide).

[0097] Figure 18 A graph is shown illustrating the correlation between interaction depth and time of flight for two different timestamping methods. The x-axis represents the energy-based DOI estimate in arbitrary units (w). E The y-axis is based on the time-based DOI (Time of Flight). There is a strong correlation between energy-based estimates and time-based estimates (using timestamps, e.g., 1 and 3). Using Equations 1 and 3 (w E and w TOF3 The correlation between the determinations of ) is stronger than that between using Equations 1 and 2 (w) E and w TOF1 The correlation between the determination of ) . For example, for w E and w TOF3 R 2 =0.53, while for w E and w TOF1 R 2 It is 0.31.

[0098] Figures 19A to 19C The estimated histograms are shown based on five different depths obtained at 2 mm, 6 mm, 10 mm, 14 mm, and 18 mm. 0 mm represents the depth at the light guide, and 20 mm represents the depth at the interface of the optical sensor array. Figure 19A Each event uses Equation 1(w) eCalculate the DOI. The frequency of each ratio is counted. The histogram is a curve. Then, convert the ratios to depth in mm. The conversion can be determined based on the following equation:

[0099] DOI = m * w + q (4)

[0100] Where m is the slope between DOI and w, and q is the intercept, which ensures that DOI starts from 0, and w is the slope between DOI and w. E (When plotting using Equation 1), w TOF1 (When plotted using Equation 2) and w TOF3 (When plotted using Equation 3). This equation is based on a standard linear regression model. When used to calculate from w... E w TOF1 and w TOF3 When determining the DOI, "m" and "q" in Equation 4 can be different.

[0101] The ratio ranges from 0 to 1. 0 can be associated with a depth of 20 mm, and 1 can be associated with a depth of 0 mm. Figure 19A The illustration shows the estimated DOI for each ground truth value, for example, 2.5mm for 2mm, 2.1mm for 6mm, 2mm for 10mm, 2.1mm for 14mm, and 2.4mm for 18mm (rounded to the nearest decimal place).

[0102] For the energy-weighted method, the estimated DOI resolution of the scintillation module with tapered shape is 2.22 mm FWHM. Figure 19A The estimated DOI resolution is determined by averaging the estimated DOI for each ground truth. For a reference scintillator array, such as a scintillator module without taper, the DOI resolution is 2.5 mm FWHM.

[0103] for Figure 19B Each event uses Equation 2(w) TOF1 The DOI is calculated using a method called [method name missing]. The frequency of each ratio is counted. The histogram is a curve. The ratios are then converted to depth in mm. This conversion can be determined based on Equation 4. Figure 19B The illustrations show the estimated DOI for each ground truth value, for example, 6.1mm for 2mm, 9.4mm for 6mm, 9mm for 10mm, 6.6mm for 14mm, and 5.6mm for 18mm (rounded to the nearest tenth). Using w TOF1 The estimated DOI resolution for the tapered scintillator module is 7.38 mm. The estimated DOI resolution is determined by averaging the estimated DOI for each ground truth.

[0104] for Figure 19C Each event uses equation 3(w) TOF3 The DOI is calculated using a method called [method name missing]. The frequency of each ratio is counted. The histogram is a curve. The ratios are then converted to depth in mm. This conversion can be determined based on Equation 4. Figure 19B The illustration shows the estimated DOI for each ground truth value, for example 5.9mm for 2mm, 5.8mm for 6mm, 5.5mm for 10mm, 5.1mm for 14mm, and 4.6mm for 18mm (rounded to the nearest tenth). Using w TOF3 The estimated DOI resolution for the tapered scintillator module is 5.38 mm. The estimated DOI resolution is determined by averaging the estimated DOI for each ground truth.

[0105] For each Figures 19A to 19C The coefficients in Equation 4 can be different.

[0106] In the discussion and claims herein, the term “(large) about” indicates that the listed value may be slightly varied, as long as such variation does not result in inconsistencies in the process or apparatus. For example, for some elements, the term “(large) about” may refer to a variation of ±0.1%, while for others it may refer to a variation of ±1% or ±10%, or any point thereof. For example, when used for measurements in mm, the term “(large) about” may include + / - 0.1, 0.2, 0.3, etc., where the difference between the stated values ​​may be significant when the numbers are large. For example, about 1.5 may include 1.2 to 1.8, while about 20 may include 19.0 to 21.0.

[0107] As used herein, the terms “approximately” or “substantially” apply equally when used with a negative connotation to refer to a complete or near-complete lack of an action, characteristic, attribute, state, structure, item, or result. For example, a “substantially” flat surface will either be perfectly flat or nearly flat, and its effect will be the same as if it were perfectly flat. “Approximately” when referring to shape or size may take into account the difficulty of manufacturing a perfect shape or size such as a circle.

[0108] As used herein, terms such as “a,” “an,” and “the” are not intended to refer to a single entity, but rather to include its general category as can be illustrated by specific examples. As used herein, terms qualified in the singular are intended to include those qualified in the plural, and vice versa.

[0109] References to “one aspect,” “some aspects,” “a few aspects,” or “one aspect” in the specification indicate that the described aspects(s) may include a particular feature or characteristic, but each aspect may not necessarily include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same aspect. Additionally, when a particular feature, structure, or characteristic is described in conjunction with one aspect, it is assumed that the combination of other aspects affects such feature, structure, or characteristic, whether or not explicitly described, and this is within the knowledge of those skilled in the art. For the purposes described below, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” and their derivatives shall refer to means relative to a floor and / or oriented as it is in the figures.

[0110] Any range of values ​​mentioned in this document explicitly includes every value contained within that range (including fractions and integers). For illustrative purposes, the range of “at least 50” or “at least approximately 50” mentioned in this document includes integers 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractions 50.1, 50.2, 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In further illustrative terms, the range of “less than 50” or “less than approximately 50” mentioned in this document includes integers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractions 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc.

[0111] As used herein, the term "processor" can include a single-core processor, a multi-core processor, multiple processors located in a single device, or multiple processors that are wired or wirelessly connected to each other and distributed across a network of devices, the Internet, or the cloud. Therefore, as used herein, a function, feature, or instruction performed or configured to be performed by a "processor" can include a function, feature, or instruction performed by a single-core processor, a function, feature, or instruction performed jointly or collaboratively by multiple cores of a multi-core processor, or a function, feature, or instruction performed jointly or collaboratively by multiple processors, wherein each processor or core does not need to perform each function, feature, or instruction individually. For example, a single FPGA or multiple FPGAs can be used to implement the functions, features, or instructions described herein. For example, multiple processors can allow for load balancing. In another example, a server (also referred to as a remote or cloud) processor can perform some or all of the functionality on behalf of a client processor.

[0112] As used herein, the terms “processor” or “controller” may be replaced by the term “circuit” (such as ASIC). The term “processor” may refer to processor hardware (shared, dedicated, or grouped) that executes code and memory hardware (shared, dedicated, or grouped) that stores the code executed by the processor, or a portion thereof.

[0113] Furthermore, in some aspects of this disclosure, a non-transitory computer-readable storage medium includes electronically readable control information stored thereon, which is configured to enable the functional aspects described herein to be implemented when the storage medium is used in a processor.

[0114] Furthermore, any of the foregoing methods can be embodied in the form of a program. This program can be stored on a non-transitory computer-readable medium and, when run on a computer device (including a processor), is adapted to perform any of the foregoing methods. Therefore, a non-transitory tangible computer-readable medium is suitable for storing information and for interacting with a data processing facility or computer device to perform the program of any of the foregoing embodiments and / or the method of any of the foregoing embodiments.

[0115] A computer-readable medium or storage medium can be an internal medium housed within the main body of a computer device, or a removable medium arranged such that it can be separated from the main body of the computer device. As used herein, the term computer-readable medium does not include transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); therefore, the term computer-readable medium is considered tangible and non-transitory. Non-limiting examples of non-transitory computer-readable media include, but are not limited to, rewritable non-volatile memory devices (including, for example, flash memory devices, erasable programmable read-only memory devices, or mask read-only memory devices); volatile memory devices (including, for example, static random access memory devices or dynamic random access memory devices); magnetic storage media (including, for example, analog or digital magnetic tape or hard disk drives); and optical storage media (including, for example, CDs, DVDs, or Blu-ray discs). Examples of media having built-in rewritable non-volatile memory include, but are not limited to, memory cards; and media having built-in ROM, including, but not limited to, ROM cartridges; and so on. Furthermore, various information about the stored image (e.g., attribute information) may be stored in any other form or may be provided in other ways.

[0116] The term memory hardware is a subset of the term computer-readable media.

[0117] The aspects and examples described in this disclosure are intended to be illustrative and not limiting, and are not intended to represent every aspect or example of this disclosure. While the essential novel features of this disclosure as applied to various specific aspects have been shown, described, and pointed out, it will also be understood that various omissions, substitutions, and changes can be made to the form and details of the illustrated devices and their operation without departing from the spirit of this disclosure. For example, all combinations of those elements and / or method steps that are explicitly intended to perform substantially the same function in substantially the same manner to achieve the same result are within the scope of this disclosure. Furthermore, it should be recognized that structures and / or elements and / or method steps shown and / or described in conjunction with any disclosed form or aspect of this disclosure can be incorporated as a general issue of design selection into any other disclosed or described or suggested form or aspect. In addition, various modifications and variations can be made without departing from the spirit or scope of this disclosure as set forth literally in the appended claims and in their legally recognized equivalents.

Claims

1. A particle detection device, comprising: An array of optical sensors arranged in a two-dimensional array, wherein there is a first gap between adjacent optical sensors, each optical sensor corresponds to a pixel and has an effective area; Multiple scintillator modules, wherein at least one scintillator module corresponds to an optical sensor in an optical sensor array, each scintillator module having a first end and a second end in contact with its corresponding optical sensor, wherein there is a second gap between adjacent scintillator modules, the second gap being the minimum gap between adjacent scintillator modules, and wherein the scintillator module adjacent to the boundary of the effective area of ​​the corresponding optical sensor has a tapered portion at its first end, such that when viewed along the longitudinal axis, a first cross-sectional area of ​​the first end overlaps with the effective area, wherein the first cross-sectional area is perpendicular to the longitudinal axis; The segmented optical guide that contacts the second end of each scintillator module Among them, some scintillator modules have a second tapered portion at their second end, and The second gap is smaller than the first gap.

2. The particle detection device according to claim 1, wherein, The second cross-sectional area above the tapered portion and below the second tapered portion is larger than the first cross-sectional area, wherein the second cross-sectional area is perpendicular to the longitudinal axis.

3. The particle detection device according to claim 2, wherein, When viewed along the longitudinal axis, at least a portion of the second cross-sectional area at the second end overlaps with the first gap.

4. The particle detection device according to any one of claims 1 to 3, wherein, The shape of the first cross-sectional area is approximately circular.

5. The particle detection device according to any one of claims 1 to 3, wherein, The at least one scintillator module is a scintillator module such that there is a one-to-one correspondence between the scintillator module and the optical sensor, wherein the first cross-sectional area of ​​each scintillator module is rectangular and tapers on all four sides at the first end.

6. The particle detection apparatus according to any one of claims 1 to 3, wherein, The at least one scintillator module includes four scintillator modules, such that there is a four-to-one correspondence between the scintillator modules and the optical sensor, wherein the first cross-sectional area of ​​each scintillator module is defined by a plurality of sides, and wherein at least two sides of the scintillator module facing the corresponding boundary of the effective area taper at a first end.

7. The particle detection device according to claim 6, wherein, Only the side of the scintillator module facing the corresponding boundary of the effective area tapers at the first end.

8. The particle detection apparatus according to any one of claims 1 to 7, wherein, The tapered portion has a tapered length in a direction parallel to the longitudinal axis, wherein the tapered length is less than one-third of the length from the first end and the second end in the direction parallel to the longitudinal axis.

9. The particle detection device according to claim 8, wherein, For each scintillator module with a tapered portion, the tapered length is approximately the same.

10. The particle detection device according to claim 8 or 9, wherein, The length from the first end to the second end is approximately 20 mm, and the tapering length is approximately 5 mm.

11. The particle detection device according to claim 2, wherein, The second cross-sectional area is 1.5 mm x 1.5 mm, and the first cross-sectional area is 1.4 mm x 1.4 mm.

12. The particle detection device according to claim 11, wherein, The effective area is 3.0 mm x 3.0 mm.

13. The particle detection apparatus according to any one of claims 1 to 12, wherein, Each segment is a pseudo-pillar, and each pseudo-pillar is configured to redirect radiating particles between the second ends of the scintillator pillar.

14. The particle detection apparatus according to any one of claims 1 to 13, further comprising reflectors located on the light guide and between segments of the light guide.

15. The particle detection apparatus according to any one of claims 1 to 14, further comprising a reflector located between each scintillator module and another scintillator module in the gap included between the tapered portions.

16. The particle detection apparatus according to any one of claims 1 to 15, wherein, The second tapered portion has a longitudinal tapered length, and the tapered length is less than the longitudinal tapered length of the tapered portion at the first end.

17. The particle detection apparatus according to any one of claims 1 to 16, wherein, The light guide segment is offset from the optical sensor, so that the first scintillator module in contact with the first optical sensor and the second scintillator module in contact with the second optical sensor are in contact with the same segment.

18. The particle detection device according to claim 17, wherein, The side of the scintillator module that tapers at the second end is different from the side of the scintillator module that tapers at the first end.

19. The particle detection device according to claim 1, wherein, These correspond to multiple scintillator modules for each optical sensor in the optical sensor array. Wherein, at least a subset of the plurality of modules corresponding to each optical sensor has a tapered portion at a first end, wherein the position of the tapered portion and which of the plurality of modules tapered depends on the relative positions of the plurality of modules within the effective area and the corresponding boundaries of the effective area.

20. The particle detection device according to claim 19, wherein, The scintillator module located at the corner of the effective area has at least two sides tapering at the first end, such that when viewed along the longitudinal axis, the first cross-sectional area of ​​the first end overlaps with the effective area, wherein the first cross-sectional area is perpendicular to the longitudinal axis.

21. The particle detection device according to claim 20, wherein, Only the two sides of the scintillator module located at the corner of the effective area taper at the first end.

22. The particle detection device according to claim 21, wherein, A scintillator module located at the corner of the effective area and aligned with other scintillator modules has only one side tapering at the first end, such that when viewed along the longitudinal axis, the first cross-sectional area of ​​the first end overlaps with the effective area, and the one side faces the boundary of the effective area.

23. The particle detection device according to claim 22, wherein, Other scintillator modules are located between the scintillator module and the boundary of the effective area. The scintillator module does not have a tapered portion at the first end.

24. A particle detection device, comprising: An array of optical sensors arranged in a two-dimensional array, wherein there is a first gap between adjacent optical sensors, each optical sensor corresponds to a pixel and has an effective area; as well as A plurality of scintillator modules, wherein at least one scintillator module corresponds to an optical sensor in an optical sensor array, each scintillator module having a first end and a second end in contact with its corresponding optical sensor, wherein there is a second gap between adjacent scintillator modules, the second gap being the minimum gap between adjacent scintillator modules, and wherein the scintillator module adjacent to the boundary of the effective area of ​​the corresponding optical sensor has a tapered portion at its first end such that, when viewed along the longitudinal axis, a first cross-sectional area of ​​the first end overlaps with the effective area, wherein the first cross-sectional area is perpendicular to the longitudinal axis. The second gap is smaller than the first gap. The at least one scintillator module comprises four scintillator modules, such that there is a four-to-one correspondence between the scintillator modules and the optical sensor, wherein the first cross-sectional area of ​​each scintillator module is defined by a plurality of sides, and wherein at least two sides of the scintillator module facing the corresponding boundary of the effective area taper at a first end. Of these, only the side of the scintillator module facing the corresponding boundary of the effective area tapers at the first end.

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