Self-contained ct scintillators within 3d-printed collimator

Abstract

To provide post-patient collimators and methods of manufacturing post-patient collimators.SOLUTION: A method includes: additively manufacturing a collimator array having a plurality of tapered cavities; positioning a plurality of scintillator pixels within the tapered cavities of the collimator array; and hardening the pixels within the tapered cavities. An example post-patient collimator 400 includes: a collimator array including a plurality of cavities, where each of the cavities 406 includes tapered walls 502; a scintillator including a plurality of pixels, each of the pixels positioned with one of the cavities of the collimator; and a reflector positioned on a top of each of the pixels.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE

[0002] Embodiments of the subject matter disclosed herein relate to diagnostic medical imaging, and more particularly, to post-collimated computed tomography imaging devices. [Background technology]

[0002] X-ray radiation detectors (detectors used in CT imaging systems) include a post-collimator assembly having a collimator and a scintillator. Typically, existing post-collimator assemblies are separate components that can be attached to one another (e.g., a collimator disposed above the scintillator or between the X-ray radiation source and the scintillator). The post-collimator assembly can be coupled to a photodiode so that data about a patient or subject being scanned in the CT imaging system can be acquired and an image can be reconstructed. Summary of the Invention

[0003] In one embodiment, a post-collimator for x-ray radiation includes a collimator array including a plurality of cavities, each cavity of the plurality of cavities including a tapered wall. The collimator array is additively manufactured. A scintillator includes a plurality of pixels, each pixel disposed in one of the plurality of cavities of the collimator. A reflector is disposed on top of each pixel of the plurality of pixels.

[0004] In another embodiment, a method of manufacturing a post-collimator for X-ray radiation includes additively manufacturing a collimator array having a plurality of tapered cavities, disposing a plurality of scintillator pixels within the collimator array, each pixel of the plurality of pixels being disposed in one of the plurality of tapered cavities, disposing a plurality of scintillator pixels within the collimator array, and curing the plurality of scintillator pixels within the tapered cavities.

[0005] It should be appreciated that the foregoing brief summary is provided to introduce in a simplified form some of the concepts that are further described in the detailed description. It is not intended to identify key features or essential features of the claimed subject matter, the scope of which is defined solely by the claims. Moreover, the claimed subject matter is not limited to implementations that solve the disadvantages noted above or anywhere in the disclosure. [Brief description of the drawings]

[0006] The invention will be better understood on reading the following description of non-limiting embodiments, with reference to the accompanying drawings, in which: [Figure 1] 1 shows a diagram of an imaging system according to one embodiment of the present invention. [Diagram 2] 1 shows a block schematic diagram of an exemplary imaging system in accordance with an embodiment of the present invention. [Diagram 3] 1 shows a current post-collimator assembly including a collimator and a scintillator. [Figure 4A-G] 4 illustrates a manufacturing process for the post-collimator assembly described herein. [Diagram 5] 4A-4G depict cross-sectional views of the exemplary post-collimator assembly. [Figure 6] FIG. 6 illustrates a top view of the exemplary post-collimator assembly shown in FIGS. 4A-5. [Figure 7] FIG. 7 illustrates a bottom view of the exemplary post-collimator assembly shown in FIGS. 4A-6. [Figure 8] 8 is an exemplary method of manufacturing the post-collimator assembly shown in FIGS. 4A-7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Described below is one or more specific embodiments. As it is intended to provide a concise description of these embodiments, not all features of an actual implementation are described herein. It should be understood that the development of any actual implementation is, like an engineering or design project, one in which numerous implementation-specific decisions must be made to achieve the developer's particular goals (such as adhering to system-related and business-related constraints that may vary from implementation to implementation). Moreover, while such a development effort may be complex and time-consuming, those of ordinary skill in the art having the benefit of this disclosure should understand that the development effort is a routine undertaking of design, fabrication, and manufacture.

[0008] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the element. The terms "comprising," "including," "having," and "including" are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the numerical examples in the following description are intended to be non-limiting, and therefore, additional numerical values, ranges, and percentages are within the scope of the disclosed embodiments.

[0009] The following description relates to various embodiments of X-ray imaging of a subject. In particular, systems and methods are provided for CT imaging using a post-collimator assembly, the post-collimator assembly including a collimator and a scintillator. FIGS. 1-2 show an exemplary embodiment of an imaging system including a post-collimator assembly disposed between a patient or subject and a detector. FIG. 3 shows an example of a prior art post-collimator assembly in which a collimator is disposed between an X-ray source and a scintillator. In particular, the collimator is layered on top of the scintillator. FIGS. 4A-4G show an exemplary manufacturing process of a collimator assembly described herein in which the collimator and scintillator are integrated. FIGS. 5-7 show an exemplary post-collimator assembly described herein, which can be manufactured using the manufacturing process shown in FIGS. 4A-4G. FIG. 8 is a flow chart showing an exemplary method of manufacturing the post-collimator of FIGS. 5-7.

[0010] Although a CT system is described as an example, it should be understood that the techniques of the present invention are useful when applied to images acquired using other imaging modalities (tomosynthesis, C-arm angiography, etc.) The CT imaging modality is described merely as an example of one suitable imaging modality.

[0011] Various embodiments may be implemented in various types of imaging systems. For example, various embodiments may be implemented in a CT imaging system in which a radiation source is collimated to lie in the xy plane of a Cartesian coordinate system and emits a fan- or cone-shaped beam, commonly referred to as an "imaging plane." An x-ray beam passes through an imaging object (such as a patient). After being attenuated by the imaging object, the x-ray beam impinges on an array of radiation detectors. The intensity of the attenuated radiation beam received at the detector array depends on the attenuation of the x-ray beam by the imaging object. Each detector element of the array produces a separate electrical signal that is a measurement of the beam intensity at the detector location. The resulting intensity measurements from all detectors are acquired separately to produce a transmission profile.

[0012] In third generation CT systems, the radiation source and detector array are rotated by the gantry in the imaging plane around the imaging object (such as a region of a subject), and the angle at which the x-ray beam intersects the imaging object is constantly changing. A full 360 degree rotation of the gantry results in a complete rotation of the gantry. A group of x-ray attenuation measurements (e.g., projection data) obtained from the detector array at one gantry angle is called a "view." Thus, a view is each incremental position of the gantry. In a "scan" of an object, a set of views are obtained at different gantry angles (view angles) during one revolution of the x-ray source and detector. In an axial diagnostic scan, the projection data is processed to construct an image corresponding to a two-dimensional slice across the imaging object. A scout scan (also referred to herein as a localizer scan) provides projection views along the longitudinal axis of the imaging object, typically providing multiple clusters, each cluster containing the internal structure of the object. One method of reconstructing an image from a set of projection data is known in the art as filtered backprojection. This process converts the attenuation measurements obtained from the scan into integers called "CT numbers" or "Hounsfield units" (HU), which are used to control the brightness of the corresponding pixel on a display.

[0013] FIG. 1 illustrates an exemplary computed tomography (CT) imaging system 10, and FIG. 2 illustrates an exemplary block diagram of an exemplary imaging system according to an embodiment of the present invention. The CT imaging system includes a gantry 12. The gantry 12 has an x-ray source 14 that generates and directs an x-ray beam 16 toward a detector assembly 15 on the opposite side of the gantry 12. The x-ray source 14 directs the x-ray beam 16, which passes through a pre-collimator assembly 13. The pre-collimator assembly 13 determines the size and shape of the x-ray beam 16, for example, using one or more filters. The detector assembly 15 includes a collimator assembly 18 (post-collimator assembly), multiple detector modules 20 (e.g., detector elements or detector sensors), and a data acquisition system (DAS) 32. The multiple detector modules 20 detect projected x-rays that pass through a subject or object 22 being imaged, and the DAS 32 converts the data into digital signals for further processing. In conventional systems, each detector module 20 generates an analog electrical signal. The analog electrical signal represents the intensity of the incident x-ray beam, and hence the attenuated beam as it passes through the subject or object 22. During a scan to acquire x-ray projection data, gantry 12 and the components mounted on the gantry rotate about a center of rotation 25 (e.g., an isocenter) to collect attenuation data from multiple view angles relative to the imaging volume.

[0014] Rotation of gantry 12 and operation of x-ray source 14 are controlled by a control system 26 of CT imaging system 10. Control system 26 includes an x-ray controller 28, which provides power and timing signals to x-ray source 14, a collimator controller 29, which controls the aperture length and width of pre-collimator 13 (and thus the size and shape of x-ray beam (e.g., x-ray beam) 16), and a gantry motor controller 30, which controls the rotational speed and rotational position of gantry 12. An image reconstructor 34 receives sampled and digitized x-ray data from DAS 32 and performs high speed image reconstruction. The reconstructed image is applied as an input to computer 36, which stores the image in storage device 38. Computer 36 also receives commands and scanning parameters from an operator through console 40. An associated display 42 allows the operator to observe the reconstructed image and other data from computer 36. The commands and parameters provided by the operator are used by computer 36 to provide control signals and information to DAS 32, x-ray controller 28, collimator controller 29, and gantry motor controller 30. Computer 36 also operates a table motor controller 44. Table motor controller 44 controls a motorized table 46 to position subject 22 and gantry 12. In particular, table 46 moves a portion of subject 22 through an opening or bore 48 in the gantry.

[0015] 3 illustrates a current post-collimator assembly 300 including a collimator 302 and a scintillator 304. An exemplary current post-collimator assembly 300 includes a collimator 302 including a plurality of collimator plates 306. The exemplary plates may be fabricated from tungsten. Alternatively, other radiation shielding materials may be used. The plurality of collimator plates 306 are shown arranged at a plurality of angles such that a row of the plurality of tungsten plates forms a curved collimator 302 that corresponds to the curvature of the gantry of the CT imaging system 10, for example, such that each x-ray radiation beam 16 travels approximately the same distance from the x-ray source 14 to the collimator 302. In an alternative example, such as that used in a standard x-ray detector, the collimator plates 306 may be arranged parallel to one another such that the plurality of collimator plates 306 form a row perpendicular to the x-ray source 14.

[0016] The exemplary post-collimator assembly 300 of FIG. 3 also includes a scintillator 304. The exemplary scintillator 304 includes a plurality of scintillator elements or pixels 308 arranged such that each scintillator element 308 is located between two of the collimator plates 306 of the collimator 302. The scintillator elements or pixels 308 may be made of a ceramic material. In the illustrated embodiment, the scintillator elements 308 are at least partially encapsulated with epoxy 310 such that the scintillator elements or pixels 308 are held in place. The scintillator elements or pixels 308 are arranged parallel to one another to form linear rows in the scintillator 302. In the illustrated example, the epoxy 310 covers the top and sides of each scintillator element or pixel 308.

[0017] An optical coupler 312 and a photodiode 314 are attached to the bottom surface of the plurality of scintillator elements 308. The exemplary optical coupler 312 may act as an optical collimator to improve the light collection efficiency of the photodiode 314. The optical coupler 312 may be attached to the scintillator element 308 by adhesive and / or epoxy 310. The exemplary photodiode 314 receives optical energy from the scintillator 302 through the optical coupler 312 and generates a corresponding electrical signal that is provided to the DAS 32 for image reconstruction.

[0018] 4A-4G illustrate a manufacturing process for a post-collimator assembly 400 as described herein. The manufacturing process for an exemplary collimator assembly begins with the fabrication of a scintillator pixel or element 402. The exemplary compact pixel or element 402 may be in the form of a compact powder of, for example, a ceramic material. The compact powder may be compressed into a truncated cone shape or a truncated pyramid shape to form a single pixel element or pixel 402. In some embodiments, the compact powder pixel or element 402 may be fabricated in a mold or using a press. In an alternative example, the scintillator pixel or element 402 is fabricated using additive manufacturing (e.g., 3D printing) from ceramic and / or resin powders.

[0019] Further, the manufacturing process of the exemplary collimator includes manufacturing an additively manufactured collimator array 404. The exemplary collimator array 404 includes a plurality of cavities or openings 406 having a truncated cone shape or a truncated pyramid shape corresponding to the shape of the exemplary scintillator elements or pixels 402. The shape of the cavities 406 results in a tapered cavity in the collimator array 404. The exemplary collimator array 404 is manufactured from tungsten. Alternatively, other materials capable of blocking x-ray radiation may be used. The exemplary collimator array 404 is preferably additively manufactured (e.g., 3D printed), although any means sufficient to manufacture the exemplary collimator array 404 may be used. In some embodiments, the exemplary collimator array 404 and the scintillator pixels 402 may be additively manufactured in tandem (i.e., each pixel is additively manufactured in a corresponding cavity simultaneously with the additive manufacturing of the collimator array) either separately or together. The truncated cone or truncated pyramid shape of the exemplary pixels 402 and cavities 406 of the collimator array 404 improves alignment of the focal spot of the X-ray radiation beam to provide optimized collimation (i.e., the cavities 406 and / or pixels 402 of the collimator assembly are focally aligned).

[0020] FIG. 4C illustrates a process of inserting one of the exemplary scintillator pixels 402 into one of the cavities 406 of the scintillator array 404. The process of inserting the exemplary scintillator pixel 402 into the cavity 406 of the collimator array 404 is performed when the exemplary scintillator pixel 402 is manufactured separately (i.e., not manufactured as an entire part). In an example where the scintillator pixel 402 and the collimator array 404 are additively manufactured in a single piece or as an entire part (e.g., using a 3D printer capable of printing with multiple materials simultaneously), the process illustrated in FIG. 4C is not necessary. Alternatively, in some exemplary manufacturing methods, the process of inserting the exemplary pixel 402 includes pouring a liquid ceramic material into the formed cavity 406 of the collimator array 404. In such an example, the manufacturing process does not include forming a pixel, but instead includes mixing a liquid ceramic material.

[0021] 4D illustrates a process of melting or curing the ceramic and / or resin powder of the exemplary scintillator pixel 402 using a sintering process or hot isostatic pressing. Melting or curing the scintillator pixel 402 in place within the collimator array cavity 406 forms a non-separable part that includes both the collimator and the scintillator in a single piece, rather than the collimator and scintillator stacked on top of each other (such as the prior art post-collimator assembly shown in FIG. 3).

[0022] 4E illustrates the process of abrading the bottom layer 408 of the collimator assembly 404 so that the bottom 410 of the scintillator pixel 402 is exposed, allowing x-ray radiation to pass completely through the pixel 402. The bottom layer 408 of the collimator array can be abraded using any means suitable for abrading the tungsten material of the collimator array 404.

[0023] In FIG. 4F, a reflective material or coating 412 is shown added to the top surface 414 of the scintillator pixel 402. The reflective material allows light to pass through in a first direction (e.g., downward through the pixel 402) but prevents light from passing through in a second direction (e.g., upward away from the pixel 402). The reflective material helps focus the light emitted from the bottom surface 410 of the pixel 402. In some examples, the reflective material can be a film attached to the top surface 414 of the pixel 402. In some examples, the reflective material can be a plate attached to the top surface 414 of the pixel. In some examples, the reflective material is an epoxy with reflective pigments (e.g., a reflective epoxy).

[0024] 4G illustrates a final step in fabricating an exemplary post-collimator assembly 400 as described herein. In an exemplary final step, a photodiode 416 is attached to the bottom surface of the pixel 402 and the bottom surface 418 of the polished collimator array 404. In some embodiments, an optical coupler 417 can be disposed between the bottom surface 418 and the photodiode 416. The exemplary photodiode 416 can be attached by adhesive, epoxy, or other suitable means. Fabricating the post-collimator assembly 400 in this manner reduces alignment errors that would typically occur if the scintillator pixel were positioned next to the scintillator array as shown in FIG. 3. This manufacturing process therefore produces a more efficient post-collimator assembly 400.

[0025] FIG. 5 shows a cross-sectional side view of the exemplary post-collimator assembly 400 shown in FIGS. 4A-4G, FIG. 6 shows a top view of the exemplary post-collimator assembly 400, and FIG. 7 shows a bottom view of the exemplary post-collimator assembly 400. As shown in FIG. 5, the multiple conical or pyramidal cavities 406 can be truncated cones and pyramidal shapes, as well as walls 502 extending between the cavities can be angled at various angles to aid in focusing the X-ray beam. For example, the walls 502 closer to the center of the post-collimator assembly 400 can be positioned at a substantially perpendicular angle (e.g., 90 degrees) to the photodiode 416. The walls 502 positioned closer to the edge 504 of the post-collimator assembly 400 can be positioned at angles that increase away from the perpendicular (e.g., less than 90 degrees, more than 90 degrees) the further away from the center the walls 502 are. 5 illustrates the post-collimator assembly 400 including six pixels 402 in cross section, however, any number of pixels may be used for the post-collimator assembly 400. Additionally, the exemplary CT imaging system 10 may include one or more of the exemplary one or more post-collimator assemblies 400 arranged adjacent to one another in a row, column, and / or multiple rows and columns to form a detector array.

[0026] 6 and 7 show top and bottom views, respectively, of an exemplary post-collimator assembly 400. The top and bottom views show pixels 402 within a cavity 402 arranged in a grid. In the illustrated embodiment, a grid including nine pixels 402 is shown, however, the exemplary post-collimator assembly 40 can include a different number of pixels depending on the size of the CT imaging system, the desired size of the detector, the number of other post-collimator assemblies 402 that are combined to form a detector, and / or manufacturing constraints on the size of the post-collimator assemblies that can be manufactured using the exemplary methods described herein.

[0027] As shown in the top view of the post-collimator assembly in FIG. 6, the top surface 602 of the exemplary pixel 402 and / or reflective material is smaller than the opening 604 of the cavity 406. FIG. 7 shows the bottom surface of the exemplary post-collimator assembly 702 without the photodiode 416 attached. The bottom surface of the pixel 402 is exposed. FIGS. 6 and 7 show the cavity 406 and pixel 402 having a shape of a truncated pyramid, as shown by the square top surface 602, opening 604, and bottom surface 606. Alternatively, if the pixel 402 and cavity 406 are in the shape of a truncated cone, the top surface, opening, and bottom surface can have a circular shape.

[0028] FIG. 8 is an exemplary method 800 for fabricating the post-collimator shown in FIGS. 4A-7. The exemplary method 800 begins with fabricating a collimator with a tapered cavity or opening using a process such as additive manufacturing (step 802). As discussed above, the tapered opening can have a tapered cone shape or a tapered pyramid shape. In step 804, pixels are fabricated from a powdered resin or ceramic material. The exemplary pixels have a shape that corresponds to the shape of the cavity of the collimator. In some embodiments, the pixels are fabricated using an additive manufacturing process at the same time as the exemplary collimator, either separately as a single part or together as a single part. In some embodiments, the method 800 proceeds to step 806, placing the pixels in the cavities. Step 806 is only required if the pixels are fabricated separately from the collimator. Then, in step 808, the pixels are cured or fused in the cavities. Step 808 can include sintering, hot isostatic pressing, or other suitable means of melting or curing the material of the pixels in the cavities. The method continues with step 810, which includes skiving the bottom layer of the collimator to expose the bottom of the pixel, which can be done using any means capable of skiving away material of the collimator. Finally, a reflective coating is added to the top surface of the pixel. The reflective coating may be applied using an adhesive or may be an epoxy with reflective pigment that is cured on the top surface of the pixel (step 812). Additionally, in some examples, the method may include attaching a photodiode to the bottom surface (step 814), for example using an adhesive or any other suitable means of attaching the photodiode to the scintillator and collimator. Method 800 is complete.

[0029] 1-7 show exemplary configurations of the relative positional relationships of various components. When elements are shown to be in direct contact with each other or to be directly connected to each other, such elements can, at least in one example, be referred to as being in direct contact with each other or directly connected to each other. Similarly, elements shown to be continuous or adjacent to each other can, at least in one example, be referred to as being continuous with each other or adjacent to each other. As an example, components that are in surface contact with each other can be referred to as being in surface contact with each other. As another example, in at least one example, elements that are spaced apart from each other, where there is only space between the elements and no other components, can be referred to as being spaced apart from each other. As yet another example, elements shown above / below each other, opposite each other, or left / right of each other can be referred to as being shown above / below each other, opposite each other, or left / right of each other. Furthermore, as shown in the figures, in at least one example, the top element or a point on the top element can be referred to as the "top" of the element, and the bottom element or a point on the bottom element can be referred to as the "bottom" of the element. As used herein, top / bottom, upper / lower, above / below are relative to the vertical axis of the figure and can be used to describe the relative location of elements of the figure with respect to one another. Thus, an element shown on top of another element is, in one example, disposed on top of the other element and in a vertical position with respect to the other element. As yet another example, the shapes of elements shown in the figures can be referred to as having those shapes (e.g., circular, rectilinear, planar, curved, rounded, chamfered, angled, etc.). Furthermore, elements shown to intersect with one another can, at least in one example, be referred to as intersecting elements or intersecting with one another. Furthermore, elements shown within or outside of another element can, in one example, be referred to as being within or outside of another element.

[0030] In this specification, an element or step described in the singular and preceded by the word "a" or "an" should be understood as not excluding a plurality of elements or steps, unless the exclusion is expressly stated. Furthermore, references to "one embodiment" of the invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, unless expressly stated to the contrary, an embodiment "comprising," "including," or "having" an element or elements having a particular characteristic may include additional elements that do not have that characteristic. The terms "including" and "in which" are used as the plain-language equivalents of the terms "comprising" and "wherein," respectively. Furthermore, terms such as "first," "second," and "third" are used merely as labels, and are not intended to impose numerical requirements and a specific positional order on the objects.

[0031] The description set forth herein uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any devices or systems, and performing any methods incorporated herein. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they contain structural elements that do not differ from the literal language of the claims, or if they contain equivalent structural elements that do not differ substantially from the literal language of the claims. [Explanation of symbols]

[0032] 10 CT Imaging System 12 Gantry 14 X-ray source 15 Detector Assembly 18 Collimator Assembly 20 Detector Module 22 Object 25 Rotation Center 26 Control System 28 X-ray Controller 29 Collimator Controller 30 Gantry motor controller 32 Data Acquisition System (DAS) 34 Configurator 36 Computer 38 Storage device 42 Display 44 Table motor controller 46 Table 48 Bore 300 Post-collimator assembly 304 Scintillator 306 Collimator Plate 310 Epoxy 312 Optical Coupler 314 Photodiode 408 Bottom layer 412 Coating 414 Top surface 416 Photodiode 417 Optical Coupler 418 Bottom 502 Wall 504 Edge 602 Top surface 604 Opening 606 Bottom 702 Post collimator assembly

Claims

1. 1. A method for manufacturing a post-collimator, comprising the steps of: Additively manufacturing a collimator array having a plurality of tapered cavities; Arranging a plurality of scintillator pixels in the collimator array, each scintillator pixel of the plurality of scintillator pixels being disposed in one of the plurality of tapered cavities; and curing the plurality of scintillator pixels within the tapered cavity; A method comprising:

2. The method of claim 1 , further comprising manufacturing the compressed pixels using additive manufacturing techniques.

3. The method of claim 1 , wherein arranging a plurality of pixels in the collimator array comprises additively fabricating each scintillator pixel of the plurality of scintillator pixels in a respective tapered cavity of the plurality of tapered cavities.

4. The method of claim 1 , further comprising polishing a bottom layer of the collimator array to expose bottom surfaces of the scintillator pixels.

5. The method of claim 1 , further comprising applying a reflective coating to a top layer of each scintillator pixel.

6. The method of claim 5 , wherein the reflective coating is a reflective epoxy or a pigmented epoxy.

7. The method of claim 5 , wherein the reflective coating is adhered to a top layer of each scintillator pixel.

8. The method of claim 1 , wherein the collimator array is additively manufactured using tungsten.

9. The method of claim 1 , wherein each scintillator pixel is a compact powder ceramic material.

10. The method of claim 1 , wherein each scintillator pixel is additively manufactured using a ceramic material.

11. The method of claim 1 , wherein disposing the plurality of scintillator pixels comprises pouring a liquid ceramic material into the plurality of tapered cavities.

12. The method of claim 1 , wherein curing the plurality of scintillator pixels comprises sintering.

13. The method of claim 1 , wherein curing the plurality of scintillator pixels comprises hot isostatic pressing.

14. 1. A post-collimator for X-ray radiation, said post-collimator comprising: a collimator array including a plurality of cavities, each cavity of the plurality of cavities including a tapered wall, the collimator array being additively manufactured; a scintillator including a plurality of pixels, each pixel of the plurality of pixels being disposed in one of the plurality of cavities of the collimator array; and A reflector disposed on each of the plurality of pixels. Including a post collimator.

15. The post-collimator of claim 14 , wherein the collimator array is additively manufactured using tungsten.

16. The post-collimator of claim 14 , wherein the pixels are additively manufactured using ceramic.

17. 15. The post-collimator of claim 14, wherein the tapered walls of each cavity of the plurality of cavities form a truncated cone-shaped cavity in which each pixel is located.

18. The post-collimator of claim 14 , wherein the tapered walls of the cavities are focused.

19. The post-collimator of claim 14, wherein the reflector is a reflective epoxy or a pigmented epoxy.

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