High-resolution, high-sensitivity pet scanner including pet detector modules

Abstract

To provide a PET detector system that overcomes defects and is cost-efficient.SOLUTION: This disclosure relates to a device including a cavity formed by a plurality of rails, the plurality of rails being connected at predetermined intervals around a first support and a second support, and at least one particle detection device being operably connected to each rail of the plurality of rails. This disclosure also relates to a scanner including the device and a processor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] [Priority Claim] Priority under 35 USC § 119 is claimed to provisional application US Serial No. 62 / 962,347, filed January 17, 2020, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to the field of radiation imaging, and more particularly to positron emission tomography (PET). [Background technology]

[0003] PET imaging is a powerful technique used primarily for the diagnosis, treatment selection, therapy monitoring, and research of cancer and neuropsychiatric disorders. Despite its high molecular specificity, quantitative nature, and clinical availability, PET has not fully realized its potential as a molecular imaging modality, primarily due to its relatively low spatial resolution (currently on the order of 3–6 mm). With this level of spatial resolution, current devices may be unable to measure small nodules or target densities in many human and rodent brain regions relevant to disease pathogenesis and pathophysiology.

[0004] Depth-encoding PET detector modules were developed to mitigate parallax errors (misplacement of response lines) in long scintillator crystals. This allows for smaller diameter PET rings, reducing component costs per detector ring, increasing the solid angle for improved sensitivity, and reducing the contribution of annihilation gamma ray colinearity to spatial resolution when using crystals with small cross sections. Furthermore, depth-of-interaction (DOI) information can be used to deconvolute photon transport within long crystals, improving timing resolution. Depth-encoding detectors based on dual-ended readout achieve the best continuous DOI resolution of less than 2 mm.

[0005] High-resolution PET systems, such as the Clear-PEM, dedicated to mammography, have been developed using dual-ended DOI readout detectors, but these systems are too costly for commercialization due to the large number of readout electronics required compared to standard single-ended readout PET scanners. Recently developed high-resolution detectors have demonstrated relatively poor energy and timing resolution. Alternative single-ended readout detector modules have been proposed, but all of these designs present tradeoffs between depth encoding, cost, scintillator-to-readout coupling ratio, crystal discrimination accuracy, energy resolution, and timing resolution. To mitigate these tradeoffs, a superior depth-encoding detector module is one with single-ended readout, in which the crystal array is directly coupled to silicon photomultiplier (SiPM) pixels without an intermediate glass light guide, minimizing the sharing of downward-traveling scintillation photons across multiple pixels while maintaining good timing resolution. Furthermore, upward-traveling photons that do not contribute timing information should be redirected by bending their path 180° toward the nearest adjacent SiPM to maintain good energy and DOI resolution and mimic the behavior of a dual-ended depth-encoding readout detector.

[0006] Therefore, detector modules consisting of unpolished polycrystalline scintillator arrays coupled 4:1 to SiPM pixels on one side and a uniform glass light guide on the other side have been investigated to develop practical, cost-effective, high-resolution time-of-flight (TOF) PET scanners and to achieve continuous DOI localization using single-ended readout. See U.S. Patent No. 6,223,499 to Frazao et al., the contents of which are incorporated herein by reference. These detector modules utilize energy-weighted averaging for crystal identification to produce a 1.53 × 1.53 × 15 mm 3 crystals and 3 x 3 mm 2Using SiPM pixels, we have achieved energy and DOI resolutions of 9% and 3 mm at full width half maximum (FWHM), respectively. However, these arrays suffer from poor crystal discrimination along edges and corners due to the lack of neighboring light sharing. This issue must be addressed, as edge and corner pixels account for 75% and 44% of the 4x4 and 8x8 SiPM readout chips, respectively. Furthermore, when using a uniform glass light guide, inter-crystal light sharing is inefficient. This is because many upward-traveling photons are reflected back into the primary column, while the remainder are isotropically shared with neighboring Gaussian intensity distributions. The problem with isotropic light sharing is the dispersion of low-intensity signals across many SiPMs. This integrity is significantly affected by dark counts, resulting in poor energy and DOI resolution.

[0007] Additionally, other PET detectors have been created to increase DOI resolution, but these detectors require a cylindrical geometry that must be large enough in diameter to span any part of the body, making the readings susceptible to geometric artifacts. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 5,059,059 [Patent Document 2] U.S. Patent Application Publication No. 16 / 899,636 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, what is desired is a PET detector system that overcomes the above-mentioned deficiencies and is cost-effective.Embodiments of the present disclosure provide devices and methods that address the above needs, as well as others. [Means for solving the problem]

[0010] In one aspect, the present disclosure relates to a device including a cavity formed by a plurality of rails connected to both a first support and a second support at predetermined intervals around the periphery of the first support and the second support, respectively, and at least one particle detection device operably connected to each rail of the plurality of rails.

[0011] In another aspect, the present disclosure is directed to a scanner and a processor that includes the device. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a PET device of the present disclosure. [Figure 2A] FIG. 1 is an exploded view of device 100 including additional elements. [Figure 2B] FIG. 1 is a cross-sectional view of a device 100. [Figure 2C] FIG. 1 is a cross-sectional view of a device 100. [Figure 3] FIG. 1 is a side view of the device 100. [Figure 4] 1 is a diagram of a PTE scanner including device 100. FIG. [Figure 5] 1 is a diagram of a PTE scanner including a device 100 and a patient. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following detailed description of the embodiments of the present disclosure is made with reference to the accompanying drawings. Descriptions of relevant functions or structures known in the art are omitted for clarity in understanding the concept of the present invention and to avoid obscuring the invention with unnecessary details. The embodiments described and disclosed herein are provided.

[0014] In the discussion and claims herein, the term "about" indicates that the listed value may vary slightly unless the variation results in a process or device non-compliance. For example, for some elements, the term "about" may refer to a variation of ±0.1%, while for other elements, the term "about" may refer to a variation of ±1% or ±10%, or any variation therein.

[0015] As used herein, the terms "substantially" or "nearly" are equally applicable when used in a negative sense to refer to completeness or near completeness lacking in an action, property, quality, state, structure, item, or result. For example, a "substantially" flat surface is completely flat or nearly so flat that it has the same effect as if it were completely flat.

[0016] As used herein, terms such as "a," "an," and "the" are not intended to refer to only a single entity, but rather include a general class of which a particular example can be used to illustrate.

[0017] As used herein, terms defined in the singular are intended to include terms defined in the plural and vice versa.

[0018] References herein to “one embodiment,” “particular embodiment,” “some embodiments,” or “embodiments” indicate that the described embodiment may include a particular feature or characteristic, but not all embodiments necessarily include the particular feature, structure, or characteristic. Furthermore, such terms do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is deemed within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly stated. For purposes of the following description, the terms “above,” “below,” “right,” “left,” “vertical,” “horizontal,” “up,” and “below,” and their derivatives, as they relate to the present invention, refer to directions in the drawings. The terms “overlying,” “above,” “located” or “located above” mean that a first element is above a second element, with an intervening element between the first and second elements. The terms “direct contact” or “attached” mean that a first element and a second element are connected without an intermediate element at the interface between the two elements.

[0019] Reference herein to any range of values ​​expressly includes each and every value within that range, including fractional and integer numbers. For purposes of illustration, reference herein to a range of "at least 50" or "at least about 50" includes all integers, such as 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers, such as 50.1, 50.2, 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In further explanation, references herein to ranges of "less than 50" or "less than about 50" include whole numbers such as the integers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, and decimals such as 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0.

[0020] A perspective view of a device 100 of the present disclosure is shown in FIG. 1. The device 100 comprises a cavity 2 extending along an axial length axis 4. The cavity 2 is formed by a plurality of rails 6 (two of which are shown in FIG. 1 ) each extending therethrough. In some embodiments, the plurality of rails 6 extend substantially parallel to the axis 4. While FIG. 1 includes 14 rails 6, in other embodiments, the device 100 may include one rail 6, two or more rails 6, any integer number between two and eighteen rails 6 (e.g., eight rails 6, ten rails 6, twelve rails 6, etc.), or more than nineteen rails 6. In some embodiments, coolant may be transmitted through any portion of each rail 6 and contact one or more portions of each particle detection device 12.

[0021] Each rail 6 may be a separate element (rod, pipe, etc.) from an individual particle detection device 12 (described in further detail below), and / or each rail may be formed by coupling adjacent detection devices 12 together in any suitable manner.

[0022] The plurality of rails 6 are connected to both the first support 8 and the second support 10 in any suitable manner (e.g., by mechanical connections such as bolts, rivets, and / or by welding). The plurality of rails 6 are connected to both the first support 8 and the second support 10 at predetermined intervals around the circumference of the first support 8 and the second support 10. These predetermined intervals are determined by the diameters of the first support 8 and the second support 10, respectively, and the number of rails 6 required to be included. Furthermore, the predetermined intervals may be the same interval between adjacent rails or may be variable intervals between adjacent rails.

[0023] Operatively connected to each rail 6 is at least one particle detection device 12. In this embodiment, each rail 6 includes ten particle detection devices 12. However, in other embodiments, each rail 6 may include one particle detection device 12, two particle detection devices 12, two to twelve particle detection devices 12, or thirteen or more particle detection devices 12. These particle detection devices 12 are discussed in more detail in U.S. Patent Application Publication No. 2007 / 0129994, the entire contents of which are incorporated by reference. Each particle detection device 12 includes at least a scintillator array including a plurality of scintillator crystals, a plurality of detectors disposed at a lower end of the scintillator array, and a plurality of prismatoids 16 components 14 disposed at an upper end of the scintillator array, each prismatoid configured to redirect particles between the upper ends of the scintillator crystals of the scintillator array, the lower ends of a first group of scintillator crystals of the scintillator array configured to direct particles toward a first detector of the plurality of detectors, and the lower ends of a second group of scintillator crystals of the scintillator array configured to direct particles toward a second detector substantially adjacent the first detector. Each of these components 12 is discussed in more detail in U.S. Patent Application Publication No. 2009 / 0129994, the entire contents of which are incorporated by reference.

[0024] The plurality of prismatoids 16 of each particle detection device 12 are directed toward the cavity 2 of the device 100. Additionally, the plurality of prismatoids 16 of each particle detection device 12 for each of the plurality of rails 6 form a substantially planar (subject to variations due to individual prismatic shapes) prismatoid surface 18, which forms a substantially planar prismatoid rail surface 20 when one or more particle detection devices 12 are operably connected to the rails 6. Thus, when the device 100 is in the configuration shown in FIG. 1, there are 14 substantially planar prismatoid rail surfaces 20.

[0025] An inner edge 9 of the first support 8 and an inner edge of the second support 10 (not visible in this view) may include a plurality of substantially flat portions that substantially correspond to the respective substantially planar prismatoid rail surfaces 20. The first support 8 and the second support 10, respectively (together with their corresponding substantially planar prismatoid rail surfaces 20) provide a cavity 2 that is substantially non-cylindrical in shape.

[0026] An exploded view of device 100 including additional elements is shown in FIG. 2A. As shown in the embodiment of FIG. 2A, an additional internal shield 30 is configured to be between each of the plurality of particle detection devices 12 and cavity 2. Internal shield 30 may be formed of any suitable material (e.g., plastic, metal, carbon-based material, ceramic, glass, combinations thereof, etc.) and may be of any suitable thickness. Internal shield 30 may include multiple substantially flat panels 31, which may be angled panels of a single piece of material or one or more pieces of material joined together to form internal shield 30. Substantially flat panels 31 may substantially correspond to each of the substantially planar prismatoid rail surfaces 20.

[0027] The dimensions of inner shield 30, and first support 8 and second support 10 are all configurable and dimensioned to substantially enclose different body parts of mammals, including, but not limited to, primates (e.g., humans and non-human primates), laboratory animals (e.g., rodents such as mice, rats, etc.), livestock (cows, pigs, sheep, horses, etc.), and domestic animals (dogs, cats, etc.). One example of a body part for which device 100 may be sized is the head and / or neck of a mammal, and another example of a body part for which device 100 may be sized is the torso of a mammal.

[0028] In this context, "sized" refers to a diameter sufficient to allow a body part to pass through with a relatively small amount of clearance between the body part and the device. In some embodiments, this size may include a more oval shape rather than the more circular shape shown in the figures. For example, when device 100 is sized for a human head, device 100 is substantially oval, such that the left-to-right dimension (minor axis) is smaller than the up-to-down dimension (major axis), approximating the oval cross-section of a human head.

[0029] An example of a device having a substantially circular cross-sectional shape is shown in FIG. 2B, where only the first support 8 is shown for illustrative purposes. As shown, the shape of the first support 8 is substantially circular with a substantially constant radius 42. Another embodiment is shown in FIG. 2C, where only the first support 8 is shown for illustrative purposes. As shown, the shape of the first support 8 is substantially oval (or substantially elliptical, substantially semicircular, substantially polygonal, or a substantially oval overall shape), with a minor axis 44 that is shorter than the major axis 46. The minor axis 44 may be shorter than the major axis 46 by any amount, such as, for example, about 0.1%, about 0.5%, about 1%, about 2.5%, about 5%, about 7.5%, about 12.5%, about 15% shorter, about 17.5%, about 20%, about 25%, about 30%, about 35%, about 40%, about 50%, about 60% or more.

[0030] In the example of FIG. 2C , when device 100 is used on a human head, the portion of device 100 near minor axis 44 would be relatively close to the human ear, while the portion of the device near major axis 46 would be relatively close to the human forehead and back of the head. Furthermore, while FIG. 2C illustrates a substantially horizontal minor axis, in other embodiments, both the minor and major axes can be at any rotational position through 360°. In both figures, first support 8 is shown without interior edge 9 in FIGS. 2B and 2C , but device 100 can be in any of the configurations shown in FIGS. 2B and 2C and still include interior edge 9, which causes device 100 to appear as a polygon, such as a three-sided polygon, a four-sided polygon, a five-sided polygon, a six-sided polygon, a seven-sided polygon, an eight-sided polygon, a nine-sided polygon, a ten-sided polygon, an eleven-sided polygon, a twelve-sided polygon, or a polygon with more sides.

[0031] Also, as shown in Figure 2A, between each of the multiple rails 6, additional internal guards 32 may extend axially along axis 4 to substantially separate adjacent rails 6 (and the particle detection devices 12 on adjacent rails 6) so that they do not have line-of-sight with one another. While Figure 2A shows an internal guard 32 between each adjacent rail 6, in other embodiments, only one internal guard 32 is included between a pair of adjacent rails 6. In other embodiments, two or more internal guards 32 are included between two or more, but not all, pairs of adjacent rails.

[0032] 2A is an additional external guard 34. The external guard 34 is configured to be between the rails 6 (and their associated particle detection device(s) 12) and the exterior of the device 100, such that along the axis 4, the additional external guard 34 separates the rails 6 (and their associated particle detection device(s) 12) from other devices and / or users of the device 100. The external guard 34 may be formed of any suitable material (e.g., plastic, metal, carbon-based material, ceramic, glass, or a combination thereof, etc.) and may be of any suitable thickness.

[0033] The outer guard 34 optionally includes a plurality of openings 36, which as shown in FIG. 2A may be axial, but in other embodiments may be in any position and in any pattern.

[0034] Device 100 may also include an additional first cap 38 and / or an additional second cap 40. First cap 38 and second cap 40 are substantially perpendicular to axis 4, each extending circumferentially in the space existing between the inner shield 30 and the outer guard 34, if both are included, and operably connecting to both the inner shield 30 and the outer guard 34. In other embodiments, only one of the inner shield 30 and the outer guard 34 is present, and in such embodiments, first cap 38 and second cap 40 are operably connected to either the inner shield 30 or the outer guard 34.

[0035] Figure 3 is a diagram of device 100 including the additional elements described with reference to Figure 2A. In this figure, device 100, including external guard 34, is in an operational configuration that may be included as part of a positron emission tomography (PTET) scanner for acquiring PET images, as shown in Figure 4.

[0036] As shown in FIG. 4, a PET scanner 200 for acquiring PET images is shown. Shown within a suitable housing 202 of the scanner 200 is the device 100. Within a patient opening 204 (substantially coaxial with axis 4 and substantially coexistent with cavity 2), a patient support 206 can be configured to be axially (substantially coaxially) movable to expose one or more selected regions of the patient for the PET scan. PET scans can be acquired in several regions, and depending on the number of positions of the patient support 206 required to cover the region to be scanned, a complete PET scan can take approximately 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 60 minutes, or more. The device 100 of the scanner 200 has the capability to scan a total axial length of up to approximately 100 cm or more.

[0037] The scanner 200 may include at least one hardware processor 208 configured to operatively communicate with each of the multiple detectors of each of the at least one particle detection device 12, either within the housing 202 of the scanner 200 itself or in a well-connected (wireless or wired) manner.

[0038] The at least one processor 208 is configured to process a plurality of algorithms, examples of which include, but are not limited to, supervised machine learning algorithms configured to perform three-dimensional (3D) gamma ray localization of at least one interaction site within at least one scintillator crystal of the plurality of scintillator crystals of one of the at least one particle detection device 12.

[0039] The at least one processor 208 may also be configured to determine Compton event localization by recovering at least one Compton event scattered among the plurality of scintillator crystals and localize the at least one Compton event at the scintillator level based on the 3D gamma-ray localization for each of the at least one particle detection device 12. The at least one processor 208 may further be configured to perform Depth of Interaction (DOI) localization within the scintillator crystals using an algorithm such as an energy weighting algorithm. The at least one processor 208 may further be configured to localize the at least one Compton event based on resolved energy of at least two interactions absorbed in the plurality of scintillator crystals, the resolved energy being based on at least one light sharing pattern and one of the at least one light sharing pattern based on positions of the plurality of scintillator crystals relative to the plurality of detectors and the plurality of prismatoids of each particle detection device 12.

[0040] Based on the various processes of processor 208 described above, processor 208 may also be configured to reconstruct both two-dimensional and three-dimensional cross-sectional images of the patient's region of interest using any suitable reconstruction algorithm.

[0041] The reconstructed image may be displayed on the display 210. As one example of the use of the display 210, the processor 208 may reconstruct the region of the patient or object being scanned from the TOF data. The reconstruction may then be used for three-dimensional rendering, multi-planar reconstruction, or two-dimensional imaging of the patient's tissue features. The image may then be displayed on the display 210. The display 210 may be a CRT, LCD, plasma screen, projector, printer, or other output device for displaying images and may be sufficiently connected (wired or wireless) to the at least one processor 208.

[0042] Furthermore, the scanner may include a control device 212 that may be configured to control the scanner 200 and the device 100. The control device 212 may have a storage medium 214 on which a computer program for controlling the scanner 200 and the device 100 is executablely stored. The scanner 200 also has an input 216 for inputting control information, e.g., imaging and examination parameters, and an output for outputting the control information and the reconstructed image.

[0043] Scanner 200 is also shown in Figure 1. In this example, the head of patient 218 is inserted into patient opening 204 in preparation for a PTE scan of the head of patient 218.

[0044] This application includes the following definitions: The term "processor" or the term "controller" may be replaced with the term "circuitry." The term "processor" refers to, is a part of, or may include processor hardware (shared, dedicated, or group) that executes code and memory hardware (shared, dedicated, or group) that stores code that is executed by the processor hardware.

[0045] A processor may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given processor of the present disclosure may be distributed among multiple processors connected via interface circuits. For example, multiple processors may enable load balancing. In a further example, a server processor (also known as a remote or cloud) may perform some or all functions on behalf of a client processor.

[0046] Furthermore, at least one embodiment of the present invention relates to a non-transitory computer-readable storage medium including electronically readable control information stored thereon, the storage medium being configured to perform at least one of the method embodiments when used in a controller of a magnetic resonance device.

[0047] Furthermore, any of the aforementioned methods can be embodied in the form of a program. The program can be stored on a non-transitory computer-readable medium and is adapted to perform any of the aforementioned methods when executed on a computing device (a device including a processor). Thus, a non-transitory, tangible computer-readable medium is adapted to store information and to interact with a data processing facility or computing device to execute the program of any of the above embodiments and / or to perform any of the methods of the above embodiments.

[0048] A computer-readable medium or storage medium may be an internal medium installed within a computer device or a removable medium arranged so as to be separated from the computer device. As used herein, the term computer-readable medium does not include transient electrical or electromagnetic signals (such as on a carrier wave) propagating through a medium. 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 (e.g., including flash memory devices, erasable programmable read-only memory devices, or masked read-only memory devices); volatile memory devices (e.g., including static random access memory devices or dynamic random access memory devices); magnetic storage media (e.g., including analog or digital magnetic tape or hard disk drives); and optical storage media (e.g., including CDs, DVDs, or Blu-ray discs). Examples of media incorporating rewritable non-volatile memory include, but are not limited to, memory cards; and media incorporating ROM, including, but not limited to, ROM cassettes. Additionally, various information about the stored images, such as property information, may be stored in other formats or provided in other ways.

[0049] The term "memory hardware" is a subset of the term "computer-readable medium." As used herein, the term "computer-readable medium" does not include transient electrical or electromagnetic signals (e.g., on carrier waves) propagating through a medium. Thus, 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 (e.g., including flash memory devices, erasable programmable read-only memory devices, or masked read-only memory devices); volatile memory devices (e.g., including static random access memory devices or dynamic random access memory devices); magnetic storage media (e.g., including analog or digital magnetic tape or hard disk drives); and optical storage media (e.g., including CDs, DVDs, or Blu-ray discs). Examples of media incorporating rewritable, non-volatile memory include, but are not limited to, memory cards; and media incorporating ROM, including, but not limited to, ROM cassettes. Furthermore, various information about stored images, such as property information, may be stored in other formats or provided in other ways.

[0050] The described embodiments and examples of the present disclosure are intended to be illustrative rather than limiting, and are not intended to represent all embodiments or examples of the present disclosure. While essential novel features of the present disclosure as applied to various specific embodiments thereof have been shown, described, and pointed out, various omissions, substitutions, and changes in the form and details of the illustrated devices and their operation may be made by those skilled in the art without departing from the spirit of the present disclosure. For example, all combinations of these elements and / or method steps that perform substantially the same function in substantially the same way to achieve the same results are expressly intended to be within the scope of the present disclosure. Furthermore, it is recognized that structures and / or elements and / or method steps shown and / or described in connection with any disclosed form or embodiment of the present disclosure may be incorporated into any other disclosed or described or proposed form or embodiment as a matter of general design choice. Moreover, various modifications and variations may be made without departing from the spirit or scope of the disclosure, both literally and in equivalents recognized in law, as set forth in the following claims. [Explanation of symbols]

[0051] 2 cavities 6 Rail 8 First Support 9 Internal Edges 10 Second Support 12 Particle detection devices 16 Prismatoid 18 Prismatoid surface 20 Prismatoid Rail Surface 30 Inner Shield Panel 31 32 Internal Guard 34 External Guard 36 Opening 38 First Cap 40 Second Cap 100 devices 200 PET scanners 202 Housing 204 Patient opening 206 Patient Support 208 processors 210 Display 212 Control Device 214 Storage medium 216 Input section 218 patients

Claims

[Claim 1] a first support; a second support axially spaced from the first support; a plurality of rails coupled to an outwardly facing side of the first support and an outwardly facing side of the second support, the plurality of rails extending between the first support and the second support, wherein at least a portion of the plurality of rails is perpendicular to the first support and the second support, the plurality of rails, the first support, and the second support define a cavity, the outwardly facing side of the first support and the outwardly facing side of the second support being opposite the sides of the first support and the second support facing the cavity, and the plurality of rails being spaced apart at predetermined intervals around the periphery of the first support and the second support; and a plurality of particle detection devices operably connected to respective ones of the plurality of rails in an array of particle detection devices, each rail radially overlapping a portion of the array of particle detection devices; each said particle detection device comprising: a scintillator array including a plurality of scintillator crystals; a plurality of detectors disposed at a first end of the scintillator array; and a plurality of prismoids disposed at a second end of the scintillator array, each of the plurality of prismoids configured to redirect between the second ends of scintillator crystals of the scintillator array; Equipped with a first end of a first group of scintillator crystals of the scintillator array configured to direct particles toward a first detector of a plurality of detectors; a first end of a second group of scintillator crystals of the scintillator array configured to direct particles toward a second detector substantially adjacent to the first detector; the plurality of prismoids of each of the particle detection devices are oriented toward the cavity; a plurality of particle detection devices operably connected to respective rails of the row of particle detection devices, wherein each of the rails radially overlaps at least a portion of the row of particle detection devices.

Images