Apparatus and method for representing an organized organization and constructing a configurable phantom thereof.

Abstract

This invention provides components and construction methods for building a wide variety of configurable phantoms for use in MR imaging. [Solution] These phantoms generally comprise an external housing; at least one support plate having multiple locations for selectively receiving at least one element, which is located within the external housing and enables the creation of a configurable phantom; at least one element having anisotropic diffusion, isotropic diffusion, and / or perfusion characteristics, which is detachably connected to one of the multiple locations on the support plate; and a matrix material contained within the external housing, which is an aqueous fluid, wherein during MR imaging, the presence of the aqueous fluid and the direction of fluid molecular diffusion within or through the at least one element are recorded in the MR image.

Description

Technical Field

[0001] Cross-references to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 093,283 filed on October 18, 2021, the entire content of U.S. Provisional Patent Application No. 63 / 093,283 is incorporated herein in its entirety.

[0002] field The present disclosure relates to apparatuses and methods for constructing a medical phantom that can be configured to include anisotropic diffusion networks and modules, as well as isotropic modules and perfusion modules, for representing organized tissue that can be used in calibration and testing of MRI devices and medical devices, and for tissue models.

Background Art

[0003] background In the medical field, medical diagnostic imaging and medical devices have important utility. Medical diagnostic imaging procedures such as magnetic resonance imaging (MR or MRI) devices are used to diagnose the conditions and pathologies of specific diseases and identify medical conditions. MR imaging can be used to identify specific tissues and structures such as peripheral nerves, such that these specific tissues and structures are avoided during surgery, and when used for brain imaging, it can provide information related to surgical intervention such as the location, size and orientation of a medical condition such as a tumor or aneurysm, and details of the nature of the medical condition. MR imaging also helps to identify critical regions of the brain that should be avoided when attempting to resect a lesion. The MR imaging modality can also exploit different properties of water and fluids that travel through tissues in the body in different ways.

[0004] A modality of MR imaging called diffusion-weighted imaging (DWI) can be used to measure the degree and direction of water diffusion through biological tissues. When water diffuses through highly organized tissue, the directions available for water molecule diffusion are uneven and distinguishable. For example, the white matter of the brain is highly organized along white matter tracts, and myelinated axons physically restrict the radial (perpendicular to the direction of the tract) movement of water, while allowing axial (along the direction of the tract) diffusion in the spaces connected between the axons that make up the tract.

[0005] A category of diffusion-weighted imaging called diffusion tensor imaging (DTI) utilizes the differences in water diffusion properties across different tissue types to provide insights into tissue cohesion and organization in organs such as the brain, as well as specific health metrics, such as those for the kidneys. Tissue type, organization (e.g., structural location), architecture (e.g., structural collocation), directional variations, and the presence of barriers are all relevant. While conventional imaging methods help distinguish tissues with different densities or responses to electromagnetic radiation (EMR) at specific wavelengths, DTI helps distinguish between tissues with organized structures and those that are unorganized or essentially homogeneous. Furthermore, it can also distinguish between tissues with organized structures or multiple structures with different orientations.

[0006] Measuring changes in water diffusion and properties, such as mean diffusivity (MD) or water direction preference (e.g., anisotropy or FA), can be used to infer details about the brain's white matter microstructure, the areas surrounding structures (e.g., lesions or tumors), substructure, damaged areas, or lesions within organs such as the brain or kidneys. For example, with respect to the substructure, measuring water diffusion can help observe the presence of a bifurcated pathway at the connection between two regions of the brain and determine the relative size of the bifurcated path based on the relative differences in diffusion properties between the two arms of the bifurcated pathway.

[0007] DTI is a powerful imaging modality in that it does not require the delivery of ionizing radiation, chemical tracers, or contrast agents. Therefore, it is ideally suited for in vivo clinical applications where knowledge of white matter structures, their integrity, and the presence of abnormalities is relevant, such as in the planning of neurosurgical interventions. Using information about the location of specific pathways, it is possible to identify this structure, or the volume containing the structure, and clinicians can choose to avoid contact with, cross, or removal of this tissue.

[0008] For example, clinicians can avoid contact with tissues where the corticospinal tract has been identified, with the aim of preventing postoperative paralysis and maintaining the patient's quality of life.

[0009] DTI may also be used to confirm the destruction of tissue structure due to traumatic or other injury, such as traumatic brain injury (TBI), hemorrhage, or stroke, and may be used to monitor neurodegenerative conditions in patients.

[0010] Diffusion-weighted MR imaging applications are limited by numerous factors, particularly when used in vivo, including the lack of methods to verify data quality or to verify the characteristics of tissue imaged by other means, such as tissue orientation, the dimensions of the structures constituting the tissue, and / or tissue integrity. Therefore, DWI applications can be carried out using a calibration source that helps to confirm the specific orientation of water molecule movement relative to the composition of magnetic components within the MRI system. For example, the person assembling the acquired images needs to know a priori how water molecule movement appears when moving head to toe relative to movement from left to right across the scanner or from top to bottom across the scanner. This helps to establish the orientation of the 3D coordinates of the DWI data. Such coordinates are often represented using a color scheme that represents three orthogonal axes. In addition, the phantom can potentially function as "ground truth," thereby providing an objective, independent, and time-invariant measure of data quality and accuracy.

[0011] Generally, changes in measurements due to DWI imaging can be classified as qualitative, where the degree of diffusion may increase or decrease relative to adjacent locations measured in the same scan, and the resulting qualitative interpretation may be, for example, better / worse, damaged / less damaged / not damaged, or healthy / necrotic. DWI imaging has a low signal-to-noise ratio and is susceptible to imaging artifacts. Means of quality assurance and quality control for DWI datasets remain barriers to their broad applicability and use.

[0012] Knowledge of potential risks in interpreting imaging data is implicit. This, coupled with the lack of quality assurance systems for datasets, leads to uncertainty and underutilization of this modality, hindering its potential use for surgical planning and diagnosis.

[0013] Another type of flow through tissue, known as perfusion, describes the delivery of nutrients and oxygen through tissue. In neurological applications, an example of perfusion MR imaging is dynamic-sensitive contrast MRI (DSC-MRI), in which a contrast agent is injected and the measurement of signal loss is recorded by T2 imaging.

[0014] Perfusion imaging is used to estimate hemodynamic characteristics such as blood flow and blood volume, and can be applied to the evaluation and management of tumors, strokes, and aneurysms. [Overview of the Initiative]

[0015] In accordance with a broad aspect of the teachings herein, at least one embodiment of a phantom for use in MR imaging is provided, the phantom comprising: an external housing; at least one support plate having a plurality of locations for selectively receiving at least one element that is disposed within the external housing and enabling the creation of a configurable phantom; at least one element having anisotropic diffusion, isotropic diffusion, and / or perfusion characteristics and being detachably connected at one of the plurality of locations on the support plate; and a matrix material contained within the external housing, the matrix material being an aqueous fluid, wherein during MR imaging, the presence of the aqueous fluid and the direction of fluid molecular diffusion within or through the at least one element are recorded in the MR image. [Effects of the Invention]

[0016] In at least one embodiment, at least one element comprises an isotropic diffusion module.

[0017] In at least one embodiment, the isotropic diffusion module has a body having first and second ends, the first end having a sealing cap, and the second end having a connector, the body containing a fluid, the connector being adapted to removably engage with a first surface of at least one support plate.

[0018] In at least one embodiment, the isotropic diffusion module is provided with an undercut at a second end that forms a bubble containment chamber.

[0019] In at least one embodiment, at least one element comprises a perfusion module that can be coupled to an external fluid source and an external fluid drain, both located outside the phantom, so that during use, fluid can flow from the external fluid source through the perfusion module to the external fluid drain.

[0020] In at least one embodiment, at least one element comprises a plurality of perfusion modules connected in series to allow a fluid to pass from an external fluid source through a series of perfusion modules to an external storage unit during use.

[0021] In at least one embodiment, the perfusion module comprises a body having first and second ends, and a plurality of rods having axes arranged along the longitudinal axis of the body, wherein the first end includes a first cap, a first permeable plate having a first surface spaced apart from the inner surface of the end of the first cap to define a first reservoir between them, and a first tube connected to the first reservoir; and the second end includes a second cap having a connector on its outer surface adapted to removably engage with the first surface of at least one support plate, a second permeable plate having a first surface spaced apart from the inner surface of the end of the second cap to define a second reservoir between them, and a second tube connected to the second reservoir, wherein the first and second tubes are coupled to the outside of the phantom to receive fluid flowing through the perfusion module during MR imaging.

[0022] In at least one embodiment, the diameter of each rod of a plurality of rods is selected to define the amount of fluid flow through the perfusion module.

[0023] In at least one embodiment, at least one element is at least one anisotropic diffusion module having a scaffold and at least one fiber network, and a plurality of openings provide the locations of any terminations, edges, and nodes of the at least one fiber network.

[0024] In at least one embodiment, the at least one anisotropic diffusion module comprises at least one support post, the at least one element optionally comprises at least one crossbar connector, and the at least one support post is removably connected to a first surface of at least one support plate and is assembled to support a fiber network.

[0025] In at least one embodiment, the at least one support post comprises a body having a first end and a second end, the first end has a first connector for removable attachment to a first support post, and the second end has a second connector for removable attachment to a support plate or a second support post.

[0026] In at least one embodiment, the at least one crossbar connector comprises at least two end caps and a bar connecting the at least two end caps, each end cap having a recess for receiving a free end of a single support post.

[0027] In at least one embodiment, the at least one fiber network comprises a fiber having at least one edge coupled to two support posts, the fiber edge having a thickness selected to provide anisotropic diffusion within a desired volume element during MR imaging.

[0028] In at least one embodiment, the at least one fiber network comprises two fiber edges joined at a node.

[0029] In at least one embodiment, the fiber edges have different thicknesses.

[0030] In at least one embodiment, the at least one fiber network comprises fibers arranged according to a network structure selected based on physiological neural structure, at least two terminations, at least one additional node, at least one edge, and optionally at least one bifurcation.

[0031] In at least one embodiment, the phantom comprises (a) at least one isotropic diffusion module, (b) at least one anisotropic diffusion module, (c) at least one perfusion diffusion module, or (d) any two of (a), (b), and (c) that are removably connected to a first surface of at least one support plate.

[0032] In at least one embodiment, at least one support plate is an axial support plate having an orientation parallel to the base of the phantom.

[0033] In at least one embodiment, at least one support plate is a vertical support plate having an orientation perpendicular to the base of the phantom.

[0034] In at least one embodiment, the vertical support plate has a first fiber network attached to its first surface and / or a second fiber network attached to its second surface.

[0035] In at least one embodiment, the first surface of at least one support plate comprises a plurality of openings adapted to receive at least one element.

[0036] In at least one embodiment, the support plate comprises a second surface facing a first surface, the second surface including a machine-readable code pattern.

[0037] In at least one embodiment, the machine-readable code pattern is a unique binary code configured to provide traveler code functionality during manufacturing and is convertible to a product identifier that includes batch information after the phantom has been constructed.

[0038] In at least one embodiment, the phantom comprises a lower plate for an external housing for securing a predetermined support plate to the external housing of the phantom, and a plurality of spacers that engage with a first set of recesses on the upper surface of the lower plate and a second set of recesses on the second surface of the predetermined support plate closest to the lower plate.

[0039] In at least one embodiment, the phantom comprises a plurality of support plates, each support plate connected to a scaffold and associated fiber network.

[0040] In at least one embodiment, at least two of the associated fiber networks have different network patterns or the same network pattern, each having different fiber materials and / or fiber arrangements to simulate different degrees of health.

[0041] In at least one embodiment, the external housing comprises at least one port adapted to receive a medical device or component of a medical device, and during use, the medical device or component of a medical device is positioned adjacent to a diffusion structure located on at least one support plate for developing a medical device having desired imaging characteristics.

[0042] In at least one embodiment, the components of the medical device include a deep brain stimulation (DBS) lead.

[0043] In accordance with another broader aspect of the teachings herein, at least one embodiment of a method for creating an anisotropic diffusion network module for a phantom is provided, comprising the steps of: (a) defining a network pattern and positioning network elements within the network pattern including terminations, at least one fiber edge, optionally at least one bifurcation, and optionally at least one intersection; (b) defining the relative positions of the network elements and the connectivity between them; (c) defining the intersections between network elements as one of contact points, partially interwoven intersections, and fully interwoven intersections; (d) defining the positions of network elements including optionally at least one isotropic diffusion module using a scaffold placed on a support plate; (e) defining an origin position to begin assembling the network pattern using fiber material for creating a model of the network; and (f) constructing a fiber network by attaching the desired fiber material to the origin position on the scaffold and weaving the fiber material around the scaffold elements according to a weaving procedure and network pattern to form an anisotropic diffusion network module.

[0044] In at least one embodiment, the method optionally includes defining relative emphasis between at least two fiber edges connected via a bifurcation or intersection.

[0045] In at least one embodiment, the fiber network has intersections greater than 0 degrees and narrower than 180 degrees.

[0046] In at least one embodiment, the method includes the step of attaching the scaffolding and fiber network together with the support plate to the inner surface of the phantom.

[0047] In at least one embodiment, the anisotropic diffusion network module is constructed to simulate the diffusion properties of a natural physiological structure.

[0048] In at least one embodiment, the fiber material is woven around a scaffolding element to form a diffusion network having diffusion properties that mimic natural physiological structures during MR imaging.

[0049] In at least one embodiment, the natural physiological structure being modeled is the corticospinal tract or the corpus callosum.

[0050] In at least one embodiment, the method includes the step of using a composite fiber for the fiber material, the composite fiber comprising an "island in the sea" fiber which includes a polymer rod covered with a soluble material.

[0051] In at least one embodiment, the method includes the step of constructing a fiber network, which includes the step of generating a first arrangement in which the fibers are spaced apart from each other in the z direction.

[0052] In at least one embodiment, the method includes the steps of submerging a fiber network in water to dissolve the fiber components and optionally heating the water to about 30-40 degrees Celsius.

[0053] In at least one embodiment, after dissolving the fiber component, the method includes the step of folding the fiber into a second arrangement.

[0054] In at least one embodiment, after folding the fibers, the method includes the steps of applying a covering to the fiber network, applying tension to the fiber network, and / or moving the ends of the fiber network to generate a final arrangement for the fiber network.

[0055] According to another broader aspect of the teachings herein, at least one embodiment of a method for constructing a parametric model for representing DTI information of a neural structure is provided, comprising the steps of: modeling a set of connected neural structures using a mapping process based on steps (a) to (c) of a method for creating an anisotropic diffusion network module to create a parametric model by defining terminals, edges having length, intersections, relative positions of intersections, types of intersections, and density of each network connection to represent the neural structure; and saving the parametric model.

[0056] In at least one embodiment, the method further includes the step of using a parametric model to reduce the file size required to store DWI or DTI information.

[0057] In at least one embodiment, the method further includes the step of using a series of parametric models having different degrees of complexity at different distances from the region of interest in order to reduce the file size required to store DWI or DTI information.

[0058] Other features and advantages of this application will become apparent from the following detailed description, along with the accompanying drawings. However, please understand that the detailed description and specific examples are given for illustrative purposes only, as they illustrate preferred embodiments of this application, while various changes and modifications within the spirit and scope of this application will become apparent to those skilled in the art from this detailed description.

[0059] To better understand the various embodiments described herein and to more clearly illustrate how these various embodiments may be carried out, at least one exemplary embodiment is shown as an example, with reference to the accompanying drawings described below. The drawings are not intended to limit the scope of the teachings described herein. [Brief explanation of the drawing]

[0060] [Figure 1A] An exemplary embodiment of the Phantom is shown. [Figure 1B] An exemplary embodiment of the Phantom is shown. [Figure 1C] An exemplary embodiment of the Phantom is shown. [Figure 2A] An exploded view of an exemplary embodiment of the Phantom is shown. [Figure 2B] An exploded view of an exemplary embodiment of the Phantom is shown. [Figure 3A] The image shows a top view of the axial support plate. [Figure 3B] The bottom view of the axial support plate is shown. [Figure 4] A perspective view of the vertical support column is shown. [Figure 5] A perspective view of the spacer is shown. [Figure 6A] A perspective view of an isotropic diffusion module is shown. [Figure 6B] A cross-sectional perspective view of an isotropic diffusion module is shown. [Figure 7A] A perspective view of the perfusion module is shown. [Figure 7B] A cross-sectional perspective view of the perfusion module is shown. [Figure 8A] A perspective view of an exemplary embodiment of a crossbar connector is shown. [Figure 8B] A top view of an exemplary embodiment of a crossbar connector is shown. [Figure 9] A schematic diagram of an example of a mathematical network that can be used to represent the fiber network used in the phantom is shown. [Figure 10A] A schematic diagram of another example of a fiber network for constructing a phantom with anisotropic diffusion is shown. [Figure 10B] This shows the assembly of an isotropic diffusion module on an axial support plate. [Figure 10C] Figure 10A shows the weaving pattern for constructing the fiber network. [Figure 10D] Figure 10A shows a perspective view of an axial support plate having an anisotropic diffusion module constructed using the fiber network shown. [Figure 11A]A schematic diagram of another example of a fiber network for constructing a phantom is shown. [Figure 11B] The steps for constructing the exemplary fiber network shown in Figure 11A are illustrated in the diagram. [Figure 11C] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11D] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11E] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11F] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11G] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11H] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 11I] This specification shows exemplary embodiments of cross modules that can be used to construct a custom phantom according to the teachings herein. [Figure 12A] A schematic diagram of an exemplary fiber network with multiple crossings and possible types of crossings, as well as different crossing angles between fiber edges, is shown. [Figure 12B] A schematic diagram of an exemplary fiber network with multiple crossings and possible types of crossings, as well as different crossing angles between fiber edges, is shown. [Figure 13A] This shows the physiological fiber network for the corticospinal tract. [Figure 13B] This shows an example of a mapping used to convert a physiological fiber network to a phantom fiber network. [Figure 13C] Figure 13B shows the resulting fiber network from the mapping. [Figure 14] A flowchart illustrating an exemplary embodiment of the process for constructing a phantom to model a natural physiological structure is shown. [Modes for carrying out the invention]

[0061] Further aspects and features of the exemplary embodiments described herein will become apparent from the following description in conjunction with the accompanying drawings.

[0062] Detailed description of the embodiment Various embodiments of the teachings herein are described below to provide examples of at least one embodiment of the claimed subject matter. No embodiment described herein is limited to any claimed subject matter. The claimed subject matter is not limited to an apparatus, system, or method having all of any one feature of any apparatus, system, or method described below, or to features common to some or all of the apparatus, systems, or methods described herein. There may be apparatus, systems, or methods described herein that are not embodiments of any claimed subject matter. Subject matter described herein but not claimed herein may be subject matter of another means of protection, for example, a continuing patent application, and the applicant, inventor, or owner does not intend to abandon, deny, or dedicate to the public such subject matter by the disclosure herein.

[0063] For the purpose of simplifying and clarifying the illustrations, reference numerals may be repeated between figures to indicate corresponding or similar elements or processes, where appropriate. In addition, numerous specific details are given to provide a complete understanding of the exemplary embodiments described herein. However, it will be understood by those skilled in the art that the exemplary embodiments described herein can be carried out without these specific details. In other examples, well-known methods, procedures, and components are not described in detail so as not to obscure the exemplary embodiments described herein. Furthermore, it should be noted that the references to the figures are provided solely to provide examples of how various exemplary physical elements and methods function in accordance with the teachings herein and should not be considered to limit the scope of the claimed subject matter. Similarly, the written descriptions should not be considered to limit the scope of the embodiments described herein.

[0064] It should also be noted that the terms “combined” or “joined” as used herein can have several different meanings depending on the context in which they are used. For example, the terms “combined” or “joined” can have a mechanical meaning. For instance, as used herein, the terms “combined” or “joined” can indicate that two elements or devices can be directly connected to each other or can be connected to each other via one or more intermediate mechanical or physical elements.

[0065] Unless the context requires otherwise, throughout this Specified and Claims, the words “comprise” and its variations such as “comprises” and “comprising” should be interpreted as having an open and inclusive meaning, i.e., “including, but not limited to.”

[0066] It should also be noted that, as used herein, the phrase "and / or" is intended to be comprehensive—that is, (or). That is, "X and / or Y" is intended to mean, for example, X or Y or both. As a further example, "X, Y, and / or Z" is intended to mean X or Y or Z or any combination thereof.

[0067] It should also be noted that, as used herein, the phrase “at least one of X, Y, and Z” is intended to encompass all combinations of X, Y, and Z, including X, Y, Z, X and Y, X and Z, Y and Y, and X, Y, and Z.

[0068] It should be noted that as used herein, terms of degree such as “substantially,” “about,” and “approximately” mean a reasonable deviation of a term that is modified in such a way that the final result does not change significantly. These terms of degree may also be interpreted to include deviations of terms modified by, for example, 1%, 2%, 5%, or 10%, provided that the deviation does not negate the meaning of the term it modifies.

[0069] Furthermore, in this specification, an enumeration of numerical ranges by endpoint includes all numbers and decimals contained within that range (for example, the range 1–5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). It should also be understood that all numbers and their fractions are presumed to be modified by the term “approximately,” meaning a variation of up to a certain amount of the number mentioned, such as 1%, 2%, 5%, or 10%, where the final result does not change significantly.

[0070] Throughout this specification, any reference to “one embodiment,” “a certain embodiment,” “at least one embodiment,” or “several embodiments” means that one or more particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments, unless they are specifically designated as incompatible or as alternative options.

[0071] As used herein and in the appended claims, the singular forms “a,” “an,” and “it” refer to multiple objects unless the context explicitly indicates otherwise. It should also be noted that the term “or” is generally used in its broadest sense, i.e., to mean “and / or” unless the context explicitly indicates otherwise.

[0072] This disclosure describes a method and associated modular apparatus having various components that can be used to generate cerebrospinal anisotropic diffusion and perfusion phantoms. Through multiple possible designs and embodiments, these phantoms may provide baseline or "ground truth" data that expands applications enabled using diffusion-weighted imaging and perfusion imaging protocols. The teachings herein may also be used to generate custom phantom embodiments for specific tasks and applications.

[0073] In one embodiment of the teachings herein, when creating a phantom using anisotropic diffusion modules, the relevant paths or natural substructures can be defined with respect to a network diagram having the locations of edges (paths), terminals (ends of paths), and nodes (intersections / junctions). The locations of the nodes may be confluences or bifurcations of paths along different paths. In the case of bifurcations (i.e., separation of paths), the proportion of fibers in each path can be determined proportionally, for example, by comparing the diameter or cross-sectional area of ​​the fiber paths, by the number of fibers in each path, or by the ratio of voxels filled by the structure, or by other means. The components described herein enable the creation of phantoms having structures that can model these bifurcations.

[0074] Referring now to Figures 1A-1C, there are perspective views of exemplary embodiments of several different phantoms 10, 50, and 70 that can be constructed according to the teachings herein. Phantoms 10, 50, and 70 include some common elements, but other elements can be included and arranged in different ways so that the phantoms have different properties and can be used to model different neural structures. The teachings herein can be used to produce a wide variety of configurable phantoms, not limited to the examples shown and / or discussed herein. The components of phantoms constructed according to the teachings herein can generally be made of MR-compatible materials. Examples include generally using acrylic for housing elements, vertical supports, and other rigid components (e.g., machined elements), and polypropylene for fibers.

[0075] Phantoms 10, 50, and 70 include an external housing sized to be compatible with scanning processes for human subjects, including compatibility with the head coil and arrangement in multiple configurations. Therefore, some exemplary embodiments for the phantoms are roughly the size of a human head and may have a diameter of about 7 inches and a length of about 170–190 mm. The external housing generally includes a cylinder 12 having side walls 12w, a top plate 14, and a substrate 16. The side walls 12w may be cylindrical or have a more complex shape closer to the shape of a biological structure, such as a head or torso. The external housing includes an internal housing. composition It includes certain components that can be called elements. The external housing and / or certain internal structures of the housing may include reference positions on its inner and outer surfaces.

[0076] In some embodiments, the external housing may include mounting locations for external connectors (e.g., for mounting pathways to access perfusion modules for providing fluid flow through them). In at least one embodiment, certain internal structures may include position indicators (such as internal reference marker positions, which can help orient the internal structures) and / or proposed internal placement locations for the medical device or its components. In at least one embodiment, the external housing may also include means (e.g., one or more ports) for inserting and positioning the medical device or components of the medical device in proximity to one or more diffusion modules mounted on the support plate 18 and positioned within the external housing, in order to determine the impact of simultaneous placement of the medical device on the data acquisition process. For example, openable ports (e.g., with screw fittings) may be used to allow placement of a deep brain stimulation (DBS) probe in proximity to an anisotropic diffusion network, for example, to see how imaging characteristics change, or to predict what imaging a patient may change after placement of the medical device. This can be used to develop a medical device with desired imaging characteristics or imaging compatibility. The outer housing is also filled with a fluid called the “matrix,” which may be water or an aqueous solution containing a disinfectant or a salt (e.g., a manganese salt or a nickel salt) that may alter the signal intensity (magnetic susceptibility) of the matrix. The top plate 14 may include taps 14t and screws (not shown), which are positioned near the edges of the plate and can be used to fill the outer housing with fluid.

[0077] Phantoms 10, 50, and 70 also generally include an axial support plate 18, spacers 20, 20a, and 20b, and various components that provide a scaffold (also called a scaffold structure) for the fiber network. The spacers 20, 20a, and 20b are mounted on the substrate 16, and the axial support plate 18 is mounted on the spacers 20, 20a, and 20b. The axial support plate 18 includes a number of openings 19 used to removably secure specific elements of the scaffold. The diameter of the axial support plate 18 is sized to be smaller than the inner diameter of the outer housing wall 12w so that it is slidably received within the wall 12w of the cylinder 12 with a small gap between them. The axial support plate 18 is coupled to the bottom plate 16 of the outer housing by the spacers 20, 20a, and 20b so that the internal components do not move relative to the outer housing of the phantom.

[0078] With respect to Figure 1A, the phantom 10 includes a scaffolding structure fabricated using support columns 24, 24a and 24b, as well as elements of a fiber network (e.g., fiber elements 26, 26a and 26b) that provide an anisotropic diffusion model. The fiber elements 26, 26a and 26b may be wrapped in a sheath in a specific manner around some of the support columns and are fixed at specific height positions on the support columns 24, 24a and 24b using fiber loops 25, 25a and 25b. The sheath helps to keep the fiber elements in place and maximize the surface area (voxels) per volume element for image scanning. The fiber elements 26, 26a and 26b, also referred to as fiber edges, intersect at a central node 27 which can be fixed using cable ties (other fastening elements may be used instead of cable ties).

[0079] With reference to Figures 1B and 2B, the phantom 50 includes a first anisotropic assembly 52a and a second anisotropic assembly 52b located at different levels (i.e., different horizontal planes (e.g., planes i.e., flat surfaces) or different heights), and includes different scaffolding structures 52 having scaffolding with associated fiber networks. In at least one embodiment, each fiber network may have different network patterns to simulate different degrees of health, including healthy and / or diseased states. Alternatively, in at least one embodiment, two fiber networks may be made of the same weaving pattern but of different fiber materials used, and the fiber material of each network may have different dimensions (e.g., different diameters, and / or cross-sectional shapes) to simulate different degrees of health. These network patterns may be determined according to the teachings herein.

[0080] For the sake of clarity, only specific elements are numbered in Figures 1B and 2B. Thus, the phantom 50 includes an axial support plate 18 and a second axial support plate 18a. The first anisotropic assembly 52a is detachably attached to the first axial support plate 18a and has a structural shape similar to the scaffolding of the phantom 10, but the first anisotropic assembly 52a uses shorter support columns so that the fibers are closer to the axial support plate 18a. The second anisotropic assembly 52b also includes shorter support columns compared to the phantom 10, but has more support columns and fiber elements arranged to have an X-shaped geometry. The axial support plates 18 and 18a are joined by connectors through openings in the axial support plates.

[0081] The two different anisotropic assemblies 52a and 52b can also be referred to as two different anisotropic diffusion modules. Thus, the anisotropic diffusion phantom can consist of multiple anisotropic diffusion modules on one axial support plate or on multiple axial support plates within the same external housing.

[0082] With respect to Figure 1C, the phantom 70 represents an isotropic diffusion phantom including a layout having two isotropic diffusion modules 72 and 72a that are detachably fixed to two openings in the support plate 18.

[0083] With respect to Figure 2A, an exploded view of Phantom 100 is shown, which includes components for constructing another different scaffold. In this case, the components include support columns 24, 24c, 24d, and 24e, isotropic diffusion modules 72 and 72a, and perfusion modules 102 and 102a. As shown, the support columns can generally be of different heights. For example, the height of support column 24 may be approximately 80 mm, while the heights of support columns 24c, 24d, and 24e may be approximately 20 mm. In other cases, the support columns may also have different circumferences to change the tension of the fiber network. The components shown in Figure 2A can be used to construct more complex phantoms. Phantoms with support columns of different heights can be used when there are two or more fiber networks attached to the same axial support plate at different heights, or when the fiber networks are arranged in directions not parallel to the plane of the axial support plate.

[0084] In accordance with the teachings of this specification, a number of components that can be found within the external housing of the configurable phantom will now be described in more detail.

[0085] Referring now to Figures 3A and 3B, which show the top and bottom views of the axial support plate 18. The axial support plate 18 is used to hold various modules and components, which can also be called elements, that constitute the internal housing of the phantom. The axial support plate 18 is typically positioned horizontally and appears in the plane of the axial slice of MR data when receiving MR imaging, so it can be said to have an axial orientation. However, in at least one alternative embodiment, the axial support plate 18 may have a different orientation and instead may be more generally called a “support plate”. The support plate 18 is typically transparent or at least translucent, allowing elements within the phantom to be viewed from various angles, which is useful when the phantom is placed in an MR unit or when confirming the placement of medical device elements within the phantom, such as DBS leads. However, the support plate 18 may not be transparent.

[0086] As previously described, the support plate 18 may have a diameter smaller than the inner diameter of the side wall 12w that provides the perimeter 18P, and is selected so that the support plate 18 can be received within the cylindrical housing 12. The thickness of the support plate 18 is generally selected to be large enough to provide sufficient physical space for an opening on one side to receive a male connector of an internal housing component and an opening on the opposite side to provide a location for a code to indicate a code. The code can be used to confirm the structure to be built, to trace a phantom during the construction process (e.g., to trace the work), or to indicate other information which will be described in more detail with respect to Figure 3B. The thickness of the support plate 18 may also be selected so that openings on either surface of the support plate do not interfere with each other even if they are in similar locations on either surface of the support plate 18.

[0087] The support plate 18 is mounted inside the cylindrical outer housing 12 and includes a plurality of openings 19 on its upper surface 18U that function as female connectors for mounting positions, and can be used to define the terminal positions, fiber network intersections, one or more anisotropic diffusion modules, one or more elements of anisotropic diffusion networks, one or more isotropic diffusion chambers and perfusion modules, etc. Components It can be used to detachably receive various elements of the phantom. One of the openings, namely opening 110, serves as the central reference point of the support plate 18, corresponding to the central axis of the phantom, and in Figure 3A, is perpendicular to the plane on which the support plate 18 is located. In the embodiments shown herein, the position of opening 19 can be positioned such that, in addition to opening 110, there are multiple locations equidistant from the central position.

[0088] Generally, the opening 19 includes threads that complement the threads on the male connecting column of the element that rotatably engages with the axial support plate 18. In an alternative embodiment, the opening 19 may be a channel with smooth sidewalls that can slidably receive the male connecting column (having a smooth outer wall) of the element attached to the support plate 18. In another embodiment, the support plate 18 may have several openings 19 with smooth sidewalls and several openings 19 with threaded sidewalls.

[0089] The upper surface 18U of the support plate 18 may also include internal reference markers 108 that enable the phantom to be registered in imaging scan data. Several internal reference markers may be present. For example, in some embodiments, there may be about five reference markers on the outside of the upper plate 14 and two reference markers located somewhere within the outer housing. Reference markers may also be present on the cylindrical edge around the perimeter 18P of the support plate 18.

[0090] The support plate 18 also has a lower surface 18L that includes recesses 21, 21a, and 21b for receiving spacers 20, 20a, and 20b, respectively. The spacers 20, 20a, and 20b connect the lower surface of the support plate 18 to the inner surface of the lower plate 16 of the outer housing 12. The spacers may have a cubic or parallelepiped shape.

[0091] The lower surface 18L of the support plate 18 may also include a grid 106 that can be used to create a unique identifier, such as a binary code, for verifying the phantom. For example, the grid 106 may include a number of openings 112 that can receive round pegs (e.g., code pin dowels) to create a machine-readable code pattern, such as a binary code pattern. In at least one exemplary embodiment, the grid 106 may include enough openings 112 to allow a 64-bit code to be debossed onto the lower surface 18L of the support plate 18. An indicator 114 may specify the orientation of the code. The binary code patterns can provide various data and functions for each support plate to which they apply, including, but are not limited to, (a) a step of confirming a specific configuration of modules for a phantom embodiment, (b) a step of confirming a series of manufacturing steps for constructing a desired / required module, (c) a step of acting as a traveler throughout the entire manufacturing process to confirm components or work in progress, (d) a step of indicating which modules to mount on the axial support plate 18, (e) a step of converting the product type identification code into a final product code for shipment to the customer, and (f) a step of assisting quality control checks to verify whether the correct phantom has been assembled. In another exemplary use, the ID code can identify anisotropic diffusion modules placed on the support plate, or once the phantom assembly process is complete, the ID code can be used to provide a complete description and unique identifier for the phantom product.

[0092] Furthermore, if the code is already being used to identify a specific product, for example, , solid Identification number (UIN)The code can be modified or added to uniquely identify clones of this product by using it. Furthermore, the traveler identification coded in grid 106 may be functionally translated into a product identification code, including product batch information, manufacturing date, location and site information, and other information related to phantom use, or for tracing, authentication, and / or identification purposes. In addition, the binary code used for traveler identification may be displayed in the image dataset output from an image scan (e.g., MR image slices), thereby being compatible with MR imaging to enable further tracing and other applications of the dataset (e.g., verifying that the same phantom was scanned at two locations and directly comparing other (e.g., patient) datasets using the phantom data as known data points).

[0093] In another embodiment, the support plate may be oriented at a 90° angle to the above and may include upright positions on both of its surfaces. The primary processing step is used to create the structure for the fiber network, i.e., it may be arranged in such a way that connections to support columns on both sides of the support plate are required during the secondary assembly process. For example, in one exemplary embodiment of a cerebral phantom, the position of the support plate corresponds to a sagittal axial plane in the brain, and the diffusion network (i.e., scaffolding and optionally fiber network) attached to the support plate represents the corpus callosum tract traversing this plane. In such a case, the support plate may be called a sagittal support plate or a vertical support plate.

[0094] Alternatively, in at least one embodiment, the phantom may include a plurality of support plates, each containing a plurality of diffusion network patterns, which can be assembled together and placed within an external housing unit. In such a case, the support plates can be modified to have through-holes to allow for the placement of fiber network edges through the planes of the support plates.

[0095] Generally, support plates can be used to support various modules, such as one or more anisotropic diffusion modules, perfusion modules, one or more isotropic diffusion modules, multiple perfusion modules, or any combination of isotropic diffusion modules, perfusion modules, and anisotropic diffusion networks.

[0096] Referring to Figure 4, it shows a perspective view of a vertical support column 24, which may also be called an upright support column. The support columns 24 may be temporary, but collectively, they can be used during the primary processing step when the fiber network structure is created on a scaffold, which is a support plate containing the required set of support columns. Alternatively, one or more support columns may be permanent and remain in place as part of the final phantom product. Generally, support columns are upright column pieces that can be used in a fiber network to define network terminations, intersection / node locations, or to create the radius of curvature of turning fibers. The support columns 24 can be removably attached to the axial support plate 18 using the reversible mating function described above. Thus, the support columns 24 can be removed, fibers can be tensioned, the support columns 24 can be repositioned to a different location on the support plate 18, and / or the support columns 24 can be rotated (e.g., 360 degrees) to incorporate twists into the fibers.

[0097] The support column 24 generally has a first end 152 and includes a body 150 formed by a cylinder or tube as a second end 154. The first end 152 includes a channel forming a female connector 150 and an annular surface around the channel forming a first shoulder or end face 158. The second end 154 includes a threaded column having a smaller diameter than the body 150, which provides a male connector 160 and an annular surface around the threaded column to form a second shoulder or annular ring 162. In some cases, if the support column 24 is intended to be permanently attached to a support plate, an adhesive or some other fastening material may be applied to the annular surface or the male connector 160. In alternative embodiments, the threaded column may have substantially the same diameter as the body 150 so that there is no annular surface. In any case, the female connector 156 is adapted to receive a male connector from another support column (not shown). The male connector 160 is adapted to be detachably connected to a female connector on another support column (not shown) or to be detachably connected at an opening 19 on the support plate 18. The support columns have bodies of different lengths, thereby providing different heights when the support columns are attached to the support plate 18. Support columns of different heights can be used in the same phantom. In some embodiments, the support columns may have different body thicknesses to support different radii of curvature for fiber network edges rotating around the support column.

[0098] When defining the origin position of the starting point of a fiber network, the position of the support plate 18 in the plane (e.g., the XY plane) can be defined by the Z coordinate defined by the position of the female used in the support plate 18 and the direction of the support column 24. In an alternative embodiment, two support columns can be connected to each other to form a higher support column, and if the male connector of the upper column engages with the female connector of the lower column, the fiber may be fixed via interference fit at a position located between them. This allows the end of the fiber to be located at the defined origin position. Using the support columns arranged on the support plate 18, an anisotropic diffusion network module, also known as a diffusion network, can be created, which is similar to a three-dimensional network diagram, having various numbers (including zero) of terminations, bifurcations, intersections, edges and / or touching or contact positions (e.g., "kiss positions") between the surfaces of adjacent edges of the network or set of networks.

[0099] Referring to Figure 5, a perspective view of the spacer 20 is shown. The spacer 20, which may also be called a standoff connector, is used to connect the support plate 18 to the inner surface of the outer housing 12. The lower surface 204 (not shown) of the spacer 20 is used to connect to the outer housing (i.e., the upper surface of the bottom plate 16), and the upper surface 202 of the spacer 20 is used to connect to the lower surface 18L of the axial support plate 18. The remaining four surfaces of the spacer (two surfaces 206 and 207 are shown) may include directional features debossed on them, such as the letter "L" on surface 206 indicating leftward direction, and the letter "A" (208) indicating forward direction (anterior-posterior). In the case of symmetrical features such as the letter "A", further directional data can be added, for example, by adding a debossed circle 210 on surface 207. If the debossed circle is on the wrong side of A in the dataset, it could mean that the dataset is reflected (mirror image), for example, with the left and right orientations reversed, which could lead to misinterpretation of the data if it's not particularly noticeable.

[0100] Figures 6A and 6B, which refer to the isotropic diffusion module 72, show a perspective view and a cross-sectional perspective view, respectively. The isotropic diffusion module is a sealed chamber configured to be mounted on the axial support plate 18 and contains a solution modified to control the viscosity characteristics of the isotropic diffusion module. For example, an aqueous solution of polyvinylpyrrolidone may be used.

[0101] The isotropic diffusion module 72 includes a body 252 having side walls 252w defining a chamber 252c internally, a first end 254, and a second end 256. The body 252 and side walls 252w may be cylindrical or of another shape in at least one embodiment, as long as one end is flat for connection to a support plate. The first end 254 of the isotropic diffusion module 72 includes a shoulder or ridge 258 and an end cap 260. The second end 256 of the isotropic diffusion module 72 includes a shoulder or ridge 262 and an end cap 264, where a male connector 266 and rib 268 define an undercut for forming a bubble containment chamber 270 between the rib 268 and the inner surface of the cap 264. The end caps 260 and 264 are sometimes referred to as sealing caps. The bubble containment chamber 270 can be used to capture bubbles below / behind the rib 268 if one or more bubbles form when the phantom is placed to its side during an MR scan procedure. Thus, any bubbles that may form are prevented from moving within the chamber 252c, which could otherwise have an undesirable effect during imaging. The cap 264 also has a flat annular surface around the male connector 266. In this exemplary embodiment, the male connector 266 is a threaded column. The male connector 266 is fitted to removably engage with the opening 19 in the upper surface 18U of the support plate 18. When a fluid of the desired viscosity is contained within the chamber 252c, and the main matrix fluid is contained within the external housing of the phantom, the sealing cap 260 isolates it from the main matrix fluid at the opposite end.

[0102] Referring to Figures 7A and 7B, perspective and cross-sectional perspective views of the perfusion module 102 are shown. The perfusion module is a chamber capable of simulating the perfusion of fluid (e.g., contrast agent, blood, or nutrients) through tissue. In this example, multiple polymer rods are used within the perfusion module 102 to divide the flow and emulate the perfusion of blood through tissue. A manifold containing the perfusion module 102 is created within the phantom, and the inlet of the perfusion module 102 may be connected to the outer surface of the phantom via a first tube, and the outlet of the perfusion module 102 may be connected to the outside of the phantom via a second tube, so that the fluid can pass from an external fluid source outside the phantom through the perfusion module 102 to an external fluid drain outside the phantom via a pump, syringe pump, or other means. In another embodiment, two or more perfusion modules may be connected in series so that the fluid passes through a series of perfusion modules before leaving the phantom. Biological structures can also be represented using the perfusion module 102. Some examples of such biological structures include, but are not limited to, the gray or white matter of the brain, or the interior of blood vessels or the interior of blood vessels including aneurysms.

[0103] As shown in Figures 7A and 7B, the perfusion module 102 generally includes a body 300 having a side wall 300w, a first end 302, and a second end 304. The body 300 and the side wall 300w may be cylindrical or of another shape in at least one embodiment, as long as one end is flat for connection to a support plate. The first end 302 of the perfusion module 300 includes an end cap 306 having a side wall 308, a tube 310, and a first permeable layer 312 (also known as a permeable plate). The side wall 308 of the end cap 306 is slidably received by the first end of the side wall 300w, where it friction-fits. Both ends of the side wall 302 and the side wall 308 have openings for receiving the tube 310. Depending on the direction of fluid flow, the tube 310 may function as an inlet port or an outlet port for receiving or discharging fluid, respectively. In at least one embodiment, the opening for receiving the tube 310 may be located in the end cap 306. The space between the interior of the end cap 306 and the upper surface of the permeable layer 312 provides a chamber 313. As the fluid moves from the first end 302 to the second end 304, the chamber 313 may create a fluid collection with substantially the same cross-sectional area inside the body 300 so that the fluid moves through substantially the entire interior of the perfusion module 102. The permeable layer 312 may be a permeable frit (e.g., frit glass) or another suitable structure that allows fluid flow through it.

[0104] The second end 306 of the perfusion module 300 includes an end cap 314 having a side wall 316, a male connector 318, an end face in the shape of an annular ring 320 positioned around the male connector, a tube 322, and a second permeable layer 324. The side wall 316 of the end cap 314 is slidably received by the second end of the side wall 300w, where it friction-fits. Both the second end of the side wall 304 and the side wall 316 have openings for receiving the tube 322. Depending on the direction of fluid flow, the tube 322 may function as an inlet port or an outlet port for receiving or discharging fluid, respectively. In at least one embodiment, the opening for receiving the tube 322 is located within the end cap 314, and the tube 322 may pass through the inside of the male connector 318. The area defined by the inner surfaces of the side walls 316 and end caps 314 and the lower surface of the second permeable layer 324 (also known as a permeable plate) defines the chamber 325 (which may also be referred to as a storage chamber). The chamber 325 can operate in the same manner as the chamber 313 to allow equivalent setups for fluid flow in both directions. A male connector 318 is used to removably connect the perfusion module to the support plate 18.

[0105] The perfusion module 102 also includes a plurality of rods 326 extending axially within the body 300 of the perfusion module 102 and arranged in a cylindrical or other configuration. The rods 326 generally have a circular cross-section and are solid. In alternative embodiments, the rods 326 may have a non-circular cross-section, such as elliptical, irregular, or another shape, as long as a space is created between the rods 326. Furthermore, or in other alternative embodiments, the rods 326 may be non-solid. For example, the rods may be pipes. In at least one embodiment, the pipes may have an internal cross-sectional area substantially the same as the space 327 between the rods, so that fluid can also flow through them. Generally, the rods 326 or pipes may have a diameter in a different range, but are not limited, which can vary by an order of magnitude or more, such as 2 to 10 micrometers or 100 to 150 micrometers. The cylindrical arrangement of the rods 326 allows for the formation of a plurality of conduits or channels between the rods 326 to enable fluid flow between the tubes 310 and 322. The volume of fluid within the perfusion module 102 can be modified by changing the diameter of the rod 326. Perfusion modules 102 with a smaller volume of fluid passing through them and a lower flow rate can be used to model physiological structures with different perfusion characteristics.

[0106] The diameter of the rods 326 in the perfusion module 102 can be selected so that the space 327 between the rods 326 supports different perfusion velocities. As the diameter of the rods 326 increases, the spacing 327 between them also increases, resulting in increased fluid flow during imaging. Therefore, the size (e.g., diameter) and / or number of the rods 326 can be selected to model different perfusion velocities through the module. For example, to model / simulate cerebral perfusion pressure, the diameter of the rods 326 and the fluid flow may be selected to provide injection velocities corresponding to a pressure gradient in the range of approximately 55–85 mgHg (mercury).

[0107] Tubes 310 and 322 are connected to the phantom's external housing and facilitate the flow of fluid through the perfusion module 102. In one exemplary embodiment, a certain length of tubing is connected to a syringe pump located at a safe distance from the MR hardware (e.g., in the control room). The syringe pump maintains a desired fluid velocity via a perfusion module manifold located on the side wall or bottom or top plate of the body of the phantom's external housing. In one example, the fluid may be a contrast agent, and the perfusion module 102 is used to verify the use of the contrast agent for structural visualization during a given scan protocol.

[0108] During use, the liquid / solution under study enters the perfusion module 102 through the inlet port of tube 310, moves to the storage chamber 313, and may enter a portion of the cylindrical body 100, including the rod 326, through the permeable layer 312. In other words, the permeable layer 312 is used to deliver the material to be perfused throughout the perfusion module 102 in the chamber 313. The rod 326 can be selected to modify the velocity of the fluid passage through the cylindrical body 100. The fluid then enters the chamber 325 through a second permeable layer 324 and exits the perfusion module 100 through tube 322, which provides an output port. The purpose of the permeable layer 314 is similar to that of the permeable layer 312, allowing for the reversal of the fluid flow within the perfusion module 102. The fluid then exits the phantom through a tube, which may be similar to the one used to introduce the fluid into the phantom.

[0109] In another embodiment, alternative embodiments of the isotropic diffusion module may exist to customize the isotropic diffusion module by allowing changes in the properties of the liquid contained within the isotropic diffusion module to suit specific needs, in accordance with the teachings of this specification. For example, the viscosity properties of the liquid may be adjusted by creating a liquid, for example, by mixing water with different amounts of polyvinylpyrrolidone (PVP) (e.g., 10 wt% PVP in water, 20-40 wt%). Once the liquid is placed in the isotropic diffusion module and the isotropic diffusion module is sealed using a sealing cap, the diffusion properties of the isotropic diffusion module are fixed.

[0110] In both isotropic diffusion modules and perfusion diffusion modules, the male connector allows the chambers of these modules to be positioned at specified locations relative to the support plate 18. In addition, in some phantoms, the outer surface of the body of the isotropic diffusion module and / or perfusion diffusion module may be used to create radii of curvature of elements of the anisotropic diffusion module, such as the edges of modules in a fiber diffusion network, but are not limited to these. For example, a phantom may have one or more elements with pre-selected radii of curvature to provide an anisotropic diffusion network that changes direction or follows curved paths within the phantom in order to model a particular physiological structure.

[0111] In accordance with the teachings herein, in another exemplary embodiment of a phantom, the phantom may have an isotropic diffusion module configuration including two or more isotropic diffusion modules having different isotropic properties, which are positioned at equal distances from the central axis of the phantom to obtain measurements of different isotropic properties. These different isotropic properties may be specified, for example, by the customer or by various health or scientific organizations such as the National Institute of Science and Technology (NIST).

[0112] In accordance with the teachings of this specification, in another exemplary phantom embodiment, the phantom may have an isotropic diffusion module configuration that includes two or more isotropic diffusion modules having equal isotropic diffusion properties, which are positioned at different locations within the phantom to confirm differences in diffusion properties (i.e., different locations) as a result of these variables.

[0113] Referring to Figures 8A and 8B, perspective and top views, respectively, of exemplary embodiments of crossbar connectors 360 and 370 are shown. Crossbar connectors 360 and 370 can be used to connect vertical support bars and can be positioned at a desired height to hold the ends in place or to maintain a desired radius of curvature for rotating the fibers. Crossbar connectors can also generally provide structural support by reinforcing extension or cantilever structures (for example, when a phantom is placed inside an imaging scanner, as modules of the diffusion network are oriented horizontally). Crossbar connectors may include caps connected by horizontal elements such as bars or rods. For example, crossbar connector 360 includes caps 362 and 364 connected by a bar 366. Caps 362 and 364 each have recesses 362R and 364R or cylindrical compartments for receiving the free ends of phantom scaffolding components, such as the free ends of vertical support columns, thereby allowing the crossbar connector 360 to connect these scaffolding components more securely. In some cases, adhesive may be used in recesses 362R and 364R. The crossbar 370 has more caps to more securely connect more vertical scaffolding components and is used in a similar manner to the crossbar connector 360. The crossbar 370 includes caps 372, 374, 376 and 378 having corresponding recesses (not shown), and a bar 376 having four arms to which each of the caps 372, 374, 376 and 378 is attached. The crossbars 360 and 370 can also be used to connect scaffolding components oriented horizontally or diagonally. In at least one embodiment, multiple crossbars (i.e., multiple) or a single crossbar may be optional. In at least one embodiment, if the crossbar is positioned at a vertical midpoint along a vertical support bar, or at a connection point between two vertical support bars joined together, at least one crossbar may not include a cap.

[0114] For alternative representations of terminations, such as a fan-shaped pattern, the phantom may include a holder with a vise or window having a shape that can be used to ensure that the fiber end is included in the desired pattern for the fiber termination.

[0115] The fibers used in the fiber network within the phantom may be made of certain materials, such as microfibers, and may have specific dimensions selected to give the desired diffusion characteristics in the final phantom product, for example, by varying the length and / or cross-sectional area of ​​the fibers. A typical example of a fiber may have a circular cross-section, which may be 0.5 to 10 microns in diameter. In at least one embodiment, the fiber diameter may be homogeneous, and the diameter of all strands is substantially equal. Alternatively, in at least one embodiment, the fibers may not be homogeneous, and the strands have a diameter in a range (e.g., about 0.5 to 2 microns). Alternatively, in at least one embodiment, there may be two or more fiber networks, one or more of which have homogeneous strands and one or more of which have non-uniform strands. Similarly, the fibers may be of the same type or a mixture of types. The fibers may be made using various polymer materials, such as polypropylene or polyethylene, but are not limited.

[0116] Anisotropic diffusion increases at the fiber surface, and by using densely packed strands of fiber, the amount of fiber surface area per unit volume can be concentrated. By changing the type of fiber or microfiber material, the amount and range of fiber surface area can be adjusted to increase or decrease the magnitude of the anisotropic diffusion signal in the image scanning protocol. Microfibers are fibers with a circular cross-section on the order of micrometers, such as about 0.5 microns, or in the range of about 1 to 50 microns. An example of a microfiber material is Islands in the Sea (INS) material, in which multiple rods of polypropylene are supplied in a soluble polyvinyl alcohol (PVA) sea.

[0117] Furthermore, by defining overlapping and intersecting nodes within a fiber network and following instructions for weaving the fibers, the assembly process can be systematized. An overlapping node in a fiber network occurs when two or more fibers in the fiber network overlap each other but are spaced vertically apart so that they do not intersect (see, for example, the image labeled 528 in Figure 11B). An intersecting node in a fiber network occurs when two or more fiber edges pass each other. Several types of intersecting nodes are possible, where fibers intersect at various angles from 0 degrees to less than 180 degrees, with 0 degrees being non-intersecting. A further understanding of the function and form of diffusion networks can be achieved through the illustrative descriptions and drawings provided herein. For example, Figures 11C–11G show various examples of bifurcated and intersecting modules that can be used to construct a custom phantom according to the teachings herein.

[0118] The external housing includes a housing 12 and upper and lower plates 14 and 16. The phantom's external housing contains internal structures and modules to facilitate additional utility. In one exemplary embodiment, the body of the housing 12 is cylindrical and includes a debossed reference position thereon, which can receive reference markers during use and support the registration of image data by a navigation system to transform different sets of image data into a single coordinate system. In some use case scenarios, this allows image datasets and hardware to be placed in the same location in the same augmented reality space. In at least one embodiment, the external housing may include ports in its side walls, bottom plate, or top plate, which may allow measurement of the phantom's internal temperature by inserting a thermometer through the ports. The ports may also provide means for inserting medical devices, such as, for example, a DBS (deep brain stimulation) lead. In at least some embodiments, the external housing may include localization markers labeled with location information, such as the head, nose, chin, or toes, to verify a specific location.

[0119] When building a fiber network, A) The absolute positions of the terminals and nodes, their relative positions to each other, and the amount of fiber used to create each edge that is joined to one or more terminals and / or one or more nodes; B) Node parameters including the following: 1) The existence and location of any binary branch; and 2) The existence and location of any intersection, including the type of intersection (e.g., partial intersection, complete intersection) and the angle of intersection, as well as the positions of those intersections on the support plate 18 having support columns. Each of these locations is defined on the support plate 18 having an opening 19; and C) Fiber origin, which is the starting position on the scaffolding support column for creating a desired fiber network having one continuous strand (multiple fiber networks may each contain their own continuous fibers), or discontinuous strands (e.g., due to lot variations), or doubling the amount of fiber distributed in each step, or having two types of fibers in the network, and mixing two fibers at once to obtain diffusion characteristics. Various parameters, including these, are defined.

[0120] If the fibers used in the fiber network require post-treatment to dissolve fiber components, such as polyvinyl alcohol (PVA) in a composite fiber containing multiple polypropylene strands held together within / by a soluble PVA domain surrounding polypropylene (or other polymer material), the fiber network may be arranged by repeatedly arranging the fibers such that some of the fibers are offset from each other along the Z direction (e.g., perpendicular to the support plate 18) to maximize the total surface area of ​​adjacent fiber portions (e.g., woven along a scaffold). The fiber arrangement on the scaffold may then be immersed in a water reservoir or an ultrasonic bath to dissolve the soluble components of the fibers. In at least one embodiment, gentle heat (e.g., 30-40 degrees Celsius) may be applied to accelerate the process.

[0121] The fiber material along each edge of the fiber network can be integrated and contained within a common sheath by removing the vertical support column at one end of the fiber network and arranging a sheath along this edge portion of the fiber connected to the end, in order to maximize the surface area density per voxel when the phantom is imaged.

[0122] To define a predetermined intersection location in the fiber network, after the support bars fixed to the support plate 18 are removed, the predetermined intersection of two portions of fiber may be constrained by a temporary fixing mechanism such as a cable tie, with the termination and edge fixed, and then the tension at the intersection is adjusted by manipulating the fiber portions at the intersection, for example by adjusting the tension along the edges near the intersection by appropriately adjusting the position of the sheath along those edges, and thus (for example by pushing the sheath toward the intersection) by incorporating a twist into the fiber portions along those edges, and by adjusting the angle of the intersection and / or the termination position of the termination (for example by removing the termination support post and moving it to a different location on the support plate). These fiber operations, including the step of applying the sheath, are sometimes called secondary operations.

[0123] After all operations, or secondary processes, have been performed to construct a fiber network having the desired characteristics (i.e., the location of nodes and terminations, and the adjustment of fiber tension for one or more edges), the support plate 18 and upright scaffolding (including vertical support bars, isotropic diffusion modules, and any combination of anisotropic diffusion modules and perfusion modules) are placed within the outer housing 12 of the phantom, along with the desired fiber network in place, and secured to the bottom plate 16 using spacers 20, 20a, and 20b. Examples of combinations of fiber networks and anisotropic diffusion modules are shown in Figures 1A, 1B, and 2B. The interior of the phantom is then filled with an aqueous solution of the phantom matrix, or an aqueous solution containing a disinfectant. The top plate 14 can then be removably secured to the top of the housing 12. It should be noted that there may be many different types of phantoms that can be constructed according to the teachings herein, including various combinations of one or more isotropic modules, fiber networks, perfusion modules, and anisotropic diffusion modules.

[0124] Steps for building a spreading network The fiber network supports anisotropic diffusion through any intersections and bifurcations within the fiber network, defined by the construction of these intersections along the direction of its edges. The fiber network may be called anisotropic diffusion module and is held in place by the arrangement of support plates, support columns, and optionally crossbars. The support plates and support columns may collectively be referred to as the scaffolding of the anisotropic diffusion module. Thus, the scaffolding may include (a) support plates, (b) at least one support column, and optionally (c) at least one crossbar connector. Note that crossbars are optional, depending on whether additional support for the fiber network is required or not.

[0125] If a phantom does not contain anisotropic diffusion modules, a scaffold is not required for the phantom. An isotropic diffusion phantom includes one or more isotropic diffusion modules placed on a support plate. An anisotropic phantom includes at least one anisotropic diffusion module and optionally at least one isotropic diffusion component and / or at least one perfusion module. A perfusion phantom includes at least one perfusion module.

[0126] When creating an anisotropic diffusion network, a primary processing step is performed to position various components of the scaffold at desired locations and to arrange the fiber network along the scaffold to follow a desired network pattern. Subsequently, a post-processing step may be applied to the fiber material to alter its material properties. For example, in the case of composite fibers containing polypropylene filaments in soluble polyvinyl alcohol (PVA) domains, the fiber network arranged in the primary processing step may be immersed in water to dissolve the PVA component. Subsequently, a secondary processing step may be applied to the fiber material to provide specific properties to various edges, terminals, and nodes so that the diffusion network has the desired diffusion properties. Examples of secondary processing steps include applying sheaths to the edges and / or adjusting the tension at the fiber edges.

[0127] Disclosed herein is at least one exemplary embodiment of a set of steps comprising a sequence of steps that can be performed to create a desired network pattern for an anisotropic spread network for a phantom, the steps resulting in an anisotropic spread network having desired and specific properties for each intersection, edge, and termination in the network. These steps may include selecting edge lengths, selecting types of intersections, selecting node locations, selecting origin locations for assembling the fiber network, and any other steps used to define the anisotropic spread network.

[0128] These procedures can be used to generate multiple anisotropic diffusion networks with equivalent properties. Therefore, multiple copies of a phantom product can be manufactured, for example, using anisotropic diffusion modules that allow for direct comparison of diffusion-weighted MR datasets acquired from equivalent but different MR units.

[0129] Furthermore, machine-readable information can be collected from binary patterns (e.g., binary codes) within a support plate that verify the intended characteristics of modules contained within the phantom product (e.g., on or on the support plate). Having a unique binary pattern allows for the identification of a specific product unit and the tracking of its entire usage.

[0130] A desired pattern of anisotropic diffusion can be described and defined by following a network diagramming method that includes the step of defining arbitrary edges, intersections, nodes and their physical properties, and then following a sequential program of stepwise procedures for creating a physical anisotropic diffusion network.

[0131] For example, referring to Figure 9, there is a schematic diagram of an example of Network 400 that can be used to represent a fiber network that may be used in a phantom. A mathematical network is defined by the locations of edges, nodes, and terminations, and their positions relative to each other. In the case of a fiber network, the ends of the fiber network can be defined as terminations (collectively, "termini"), the bifurcates and / or intersections within the fiber can be defined as nodes, and the fiber paths between terminations and nodes can be defined as edges.

[0132] Example 1 Referring now to Figure 10A, a schematic diagram of an example of a fiber network 450 for constructing a phantom with anisotropic diffusion is shown. The fiber network 450 includes three terminations 452, 454, and 456 at locations A, B, and C, a node 458 located at location X, and edges 460, 462, and 464. Referring now to Figure 10B, the fiber network 450 can be created by arranging four vertical support columns 474, 474a, 474b, and 474c at locations A, B, C, and X on a support plate 472, and fixing fiber or microfiber material at a selected origin position by using interference fitting between the upper surface of a first support column and the lower surface of a second support column, which are vertically arranged using appropriate knots or adhesives, for example, as two vertical support columns or through holes made in the vertical support columns, or by using a combination of processes for fixing one end of a fiber or microfiber thereto. For example, the origin position may be selected to be location A.

[0133] Fibers or microfibers may be woven in a pattern to create a network that includes nodes at position X, terminations at positions A, B, and C, and edges |AX|, |BX|, and |CX|, as well as relative emphasis between these edges. For example, edge |AX| may be evenly divided at node X between |BX| and |CX|, and the weaving pattern may follow as shown graphically in Figure 10C and listed in Table 1. Steps 1-8 can be repeated to create fiber networks with a larger quantity of fibers and a larger diameter.

[0134] Table 1 - Process for creating network 450 [Table 1]

[0135] For the ratio of edges |BX|:|CX|, if there are different emphasis ratios between two edges, such as 75%:25%, steps 1-4 may be repeated three times for each of steps 5-8.

[0136] An example of a fiber network in this respect is shown as fiber network 470 in Figure 10D, where the edges |AX|, |BX|, and |CX| are represented by fiber portions 480, 480a, and 480b, and node X is represented by fiber crossing 484.

[0137] The weaving processes described in Table 1 can be collectively referred to as the primary fiber network assembly process.

[0138] If terminals B and C are nodes, and the fiber is further divided into multiple smaller branches from there, more complex division patterns may be possible.

[0139] Secondary processing step The processing steps described in the paragraphs of this section can be collectively referred to as secondary processing steps.

[0140] In some cases, the fibers used to create the diffusion network pattern may require post-processing, such as applying chemical treatment to the fibers, but are not limited to these. For example, when using a composite fiber called an island-in-the-sea fiber, which contains microrods of polymer material encapsulated in a water-soluble PVA material, post-processing can be performed by exposing the fiber network to water to dissolve the water-soluble PVA material. This may be done to position the microrods of polymer material so that tension can be adjusted along one or more edges of the fiber network. For example, positions A, B, C and X may be defined within a common plane, and the iterative weaving process may be offset in a direction perpendicular to this plane (see, for example, process 528 in Figure 11B) to maximize the surface area of ​​the fiber material available for post-processing.

[0141] Continuing with the example in Figure 10B, the support plate 472, together with the support columns 474, 474a, 474b, and 474c, holds the edges of the fiber network in place and allows them to be manipulated individually. For example, some of the fibers deposited by steps 1, 4, 5, and 8 in Table 1 may be adjusted by collapsing the fiber or microfiber edges into a single larger network edge |AX|, removing the vertical column 474b at position A, wrapping the network edge |AX| in the sheath, reinserting the vertical support column 474b through the fiber loop at position A, and reattaching the vertical support column 474b to the support plate 472.

[0142] For fiber materials where post-processing alters the tension within the fiber along the network edge, the tension can be adjusted by removing a vertical support column from a predetermined location on a support plate representing the end of the fiber edge, rotating the vertical support plate to introduce twist into the fiber edge, and replacing the vertical support column at the predetermined location on the support plate. Furthermore, to maintain or adjust the tension of a portion of the fiber network, the diameter of the support column(s) adjacent to that portion of the fiber network may be changed.

[0143] Example 2 In Example 2, the fiber network 500, whose schematic diagram is shown in Figure 11A, can be described as having four terminations at locations A, B, C, and D, intersecting at a node at location X, and having edges |AX|, |BX|, |CX|, and |DX|. There are more options for defining this intersection X. Vertical support columns 502, 504, 506, 508, and 510 are positioned in openings on support plates at locations A, B, C, D, and X. A procedure 520 for forming the fiber network 500 is shown in Figure 11B, in which a first step 522 includes positioning the support columns at locations A, B, C, D, and X.

[0144] Next, as shown in step 524, the weaving begins by defining the support column 502 at location A as the origin, wrapping the end of the fiber around the support column 502, and then proceeding to wrap the fiber around the support column 506 at location C. For a fiber network having a contact point at node X, where the fibers touch or kiss at node X and have equal weight N, the weaving may include the step of weaving the loop of the fiber N times clockwise around both support columns 502 and 506 at locations A and C to form edge |AC|, and then weaving |AXB| clockwise around support column 510 at location X, and then around support column 504 at location B, as shown in step 526. Next, as shown in step 528, the weaving includes the step of weaving the loop of the fiber N times clockwise around support columns 504 and 508 at locations B and D to form edge |BD|. By appropriately increasing the value of N, the effect of weaving |AXB| clockwise around the support column 510 at position X is minimized.

[0145] For example, the diffuse network pattern shown in Figure 11A can be described as having two intersecting diffuse edges (i.e., two intersecting fibers), where the first edge |AC| is located between terminals A and C at an intersecting node located at position X, and the second edge |BD| is located between terminals B and D. The assembly procedure for a fiber with its origin at A is as follows: 1. The process of forming edge |AC| by starting from support column 502 at location A and then looping the fiber clockwise around support column 506 at location C; 2. The process of forming an edge |CA| by looping the fiber clockwise around the support column 502 at location A; 3. The process of forming the edge |AX| by looping the fiber clockwise around the support column 510 at location X; 4. The process of forming edge |XB| by looping the fiber clockwise around support column 504 at location B; 5. The process of forming the edge |BD| by looping the fiber clockwise around the support column 508 at location D; 6. The process of forming edge |DB| by looping the fiber clockwise around the support column 504 at location B; 7. The process of forming an edge |BX| by looping the fiber counterclockwise around the support column 510 at location X; and 8. The process of forming edge |XA| by looping the fiber clockwise around the support column 502 at location A. It may be defined as follows, and by repeating steps 1 and 2 N times, a larger edge |AC| can be created; steps 3 and 4 are performed once; and by repeating steps 5 and 6 M times, a larger edge |BD| can be created. The integers M and N may be varied from 1 to approximately 1,000 to 10,000 or more in order to increase the thickness of the desired fiber edge. When M is equal to N, fibers of equal size are constructed for edges |AC| and |BD|.

[0146] An offset weave node may be created by combining a contact operation and a weaving operation. An example of a contact operation is when fiber edges are positioned adjacent to each other and then folded into the fiber edges, an example of which is step 530 in Figure 11B. An example of a weave operation is when, before following the weave operation described above, fibers are repeatedly distributed from support column 502 at location A to support column 506 at location C, and then back from support column 506 at location C to support column 502 at location A, and then the loop is repeated from support column 504 at location B to support column 508 at location D, and then back from support column 508 at location D to support column 504 at location B, thereby creating a weave node at a location such as location X.

[0147] In this example, the interwoven fibers pass straight through the intersection at a 90-degree crossing angle, but the fibers may also be rotated 90 degrees at the intersection, resulting in the intersection of edge |AB| with edge |CD| instead of the intersection of edge |AC| with edge |BD|, where each of edges |AB| and |CD| includes a 90-degree angle at the intersection X. By swapping the assembly process of the diffusion network, the properties of intersections of different pathways in the neural structure can be modeled, and the crossing angle can be controlled for different edges in the modeled and idealized structures.

[0148] Furthermore, in alternative embodiments, multiple different angles can be implemented within the fiber network.

[0149] For example, referring to Figure 11C, there is an example of a phantom containing three modules: a 180-degree crossing network (e.g., Figure 11F) and a 90-degree crossing network (e.g., Figure 11G) at the bottom layer of the phantom, and an asymmetric binary branch network (e.g., Figures 11D and 11E) at the top layer of the phantom. Modules ABCD are 180-degree lines of sight with fibers passing straight through the intersections. Branch AX = 55 mm long, 1 / 4 inch in diameter, containing 48,000 fibers; Branch BX = 20 mm long, 1 / 4 inch in diameter, containing 48,000 fibers; Branch CX = 14 mm long, 1 / 4 inch in diameter, containing 48,000 fibers; Branch DX = 25 mm long, 1 / 4 inch in diameter, containing 48,000 fibers. Modules EFGH are 90-degree lines of sight where the fibers rotate 90 degrees at the intersections. Branch EX = 23 mm in length, 1 / 4 inch in diameter, containing 36,000 fibers; Branch FX = 55 mm in length, 1 / 4 inch in diameter, containing 36,000 fibers; Branch GX = 16 mm in length, 1 / 4 inch in diameter, containing 36,000 fibers; Branch HX = 25 mm in length, 1 / 4 inch in diameter, containing 36,000 fibers. In asymmetrical bibranch modules, Branch AX = 60 mm in length, 3 / 4 inch in diameter, containing 174,000 fibers; Branch BX = 48 mm in length, 1 / 4 inch in diameter, containing 78,000 fibers; Branch CX = 38 mm in length, 1 / 4 inch in diameter, containing 48,000 fibers; and Branch DX = 50 mm in length, 1 / 4 inch in diameter, containing 48,000 fibers.

[0150] Referring now to Figure 11D, it shows an exemplary embodiment of a bifurcated model construction including branch AX with 1,450 loops and 174,000 fibers, branch BX with 650 loops and 78,000 fibers, branch CX with 400 loops and 48,000 fibers, and branch D-XX with 400 loops and 48,000 fibers. Figure 11E shows an example of a real bifurcated model corresponding to the model shown in Figure 11D.

[0151] Referring now to Figure 11F, an exemplary embodiment of a 180-degree cross model can be used with phantoms in which fiber networks are arranged vertically and horizontally. The 180-degree cross model includes branch AX with 400 loops and 48,000 fibers, branch BX with 400 loops and 48,000 fibers, branch CX with 400 loops and 48,000 fibers, and branch DX with 400 loops and 48,000 fibers. A step-by-step method for constructing the 180-degree cross model is shown in Figure 11H.

[0152] Referring now to Figure 11G, there is an exemplary embodiment of a 90-degree cross model in which the fiber network is arranged vertically and horizontally, but which can be used with a phantom that encloses a portion of the support column that is bent at 90 degrees. The 90-degree cross model includes branch E-XX with 300 loops and 36,000 fibers, branch F-XX with 300 loops and 36,000 fibers, branch G-XX with 300 loops and 36,000 fibers, and branch H-XX with 300 loops and 36,000 fibers. A step-by-step method for constructing a 180-degree cross model is shown in Figure 11I.

[0153] In at least one embodiment, the weaving operation may be performed by a machine according to a software procedure.

[0154] Example 3 Based on the above example 2, it can be inferred that more complex network patterns can be created using multiple types of intersections present within the same fiber network. Schematic diagrams of such fiber network examples are shown in Figures 12A and 12B as fiber networks 535 and 540, respectively. Furthermore, the fiber networks can be assembled independently through secondary processing steps combined on the same scaffolding structure. Therefore, multiple diffusion network modules can be held using a scaffolding structure equipped with support plates and vertical support columns.

[0155] Example 4 Examples 1, 2, and 3 illustrate an ideal structure. In this example, a natural physiological structure such as the human corticospinal tract shown in Figure 13A can be modeled by defining the location and connectivity of specific elements, such as the eight elements shown in Figure 13B, and these elements are then transformed into two simple networks A and B that can be used to construct a fiber network using the method described above, as shown in Figure 13C. Figure 14 shows a flowchart of an exemplary embodiment of Method 600 that can be used to create a phantom using the network diagram shown in Figure 13C. Elements defined for the natural physiological structure shown in Figure 13B include terminals (1, 6, and 7), bifurcations (4, and 8), and crossing or contact points (5). Step 602 of Method 600 is performed first, which includes defining and positioning network elements, including terminals, at least one bifurcation, at least one crossing, and at least one edge, to be used in the fiber network to model the natural structure. Depending on the natural physiological structure, at least one crossing and at least one bifurcation may be optional. Next, step 604 of method 600 is performed, which includes defining the relative positions of network elements and the connectivity between these elements. For example, the connectivity between the eight elements in Figure 13B is defined by the edges in Figure 13C to biomimetic the same connectivity found in natural structures. Next, step 606 of method 600 is performed, which selects the characteristics of a bifurcation by defining the relative emphasis between fiber edges connected via bifurcation or crossing, with emphasis assigned to different edges. Different weights of edges can be achieved by changing the amount of fiber within the edge, thereby changing the amount of surface area of ​​fiber contained within a given edge element of the fiber network. Next, step 608 of method 600 is performed, which includes defining the properties of any crossing used, such as whether the crossing is a contact point, pinched, partially interwoven, or completely pinched. For example, bifurcation section 4 in Figure 13B can be fabricated using a 50:50 fiber distribution at terminals 2 and 3 in Figure 13C.Next, step 610 of Method 600 is performed to define these locations within the hardware model (i.e., the scaffold structure and any optional diffusion module). Steps 612 and 614 of Method 600 define the origin location to begin assembling the network pattern using fiber material to create a model of the network, and then apply the fibers to the scaffold using the desired fiber material, and perform a weaving procedure, such as those shown in Examples 1 and 2, to construct a diffusion network for a phantom that mimics the target structure shown in Figure 13A. In this particular example, the end of network A at location 1 can be placed within an enclosure, such as a holder with a vise or window that constrains its position to create a fanning end of the structure to be modeled, as described earlier.

[0156] Once the anisotropic diffusion network or assembly of anisotropic diffusion networks is assembled, Method 600 proceeds to step 616, in which a scaffold including support plates and vertical support columns is attached to the inner surface of the phantom's outer housing, along with the fiber network(s). The interior of the outer housing may then be filled with water or another aqueous solution, and then the upper support plates may be fixed to the outer housing to complete the phantom.

[0157] Matrix materials The material filling the outer housing is called the aqueous matrix material. The aqueous matrix material may be a fluid such as water, or an aqueous-based solution of a salt such as copper sulfate, or another aqueous material, or it may contain, for example, a disinfectant. The interior of the phantom is filled with liquid. Small bubbles may remain in each domain that can absorb pressure changes due to temperature changes of the liquid that may occur during transport and storage. The term "domain" refers to a separate continuous volume within the phantom. For example, the interior space of the phantom containing the aqueous matrix material can be considered the first domain, the interior of the isotropic diffusion module can be considered the second domain, and the interior of the perfusion module, including the inside of the tubes connecting the perfusion module to the outside of the outer housing, can be considered the third domain. During MR imaging, the presence and direction of diffusion of the fluid are recorded in the MR image. Fluid diffusion is the movement of molecules that can be characterized as isotropic (i.e., fluid molecules move equally in all directions) or anisotropic (i.e., fluid molecules move in a specific direction within the fiber network).

[0158] Examples of Phantom use based on the instructions in this specification The diffusion phantom described herein can be used as a calibration device for various diffusion-weighted magnetic resonance imaging (DW-MRI) modalities.

[0159] Phantoms constructed according to the teachings herein have a defined structure with known properties, including edge length and known types of intersections, thereby enabling reproducible accuracy, precision, and artifact assessment when evaluating datasets obtained by applying DW-MRI imaging protocols to these phantoms.

[0160] In another embodiment, a phantom can be used to post-process primary image data created in a diffusion imaging process, and an algorithm, such as processing software, can evaluate whether it correctly interprets the primary image data describing the crossings and outputs the correct paths of fibers through the crossings. This could potentially validate magnetic resonance scanning protocols and verify how they indicate which regions of the brain are connected, how they are connected by which paths, and the extent of the connections.

[0161] To mimic white matter with different diffusion properties, fiber or microfiber materials with different diffusion properties (such as larger diameter, smaller diameter, and mixed diameter) may be used to adjust the fiber surface area and amount of water within each voxel of the image data, as well as the degree to which water diffusion is restricted. By changing the dimensions of the material used for the fiber, such as the diameter of the material, it is possible to model the properties of different tissue types, such as white matter, including healthy tissue, diseased states, and developmental states, within different phantoms or as modules within the same phantom.

[0162] As mentioned above, access ports within the side walls, top plate, or bottom plate of the external housing may allow for the placement of medical devices such as deep brain simulation (DBS) leads to probe changes in image data resulting from altered proximity of the medical device to the phantom portion simulating the fiber pathway. Through the process of scanning the medical device and anisotropic diffusion network, the impact of the placement of the medical device and implant on the ability to image patients after medical procedures can be evaluated and quantified, and changes in the development of medical devices can be predicted and explained. Furthermore, the interpretation of scan results from patients with these medical implants can be better predicted and interpreted.

[0163] A utility that represents DTI using a set of parameters. DTI is a representation of neural structures derived from the estimation of water molecule diffusion pathways. Traditionally, fully representing such neural structures requires high initial computational costs to model the various pathways of water molecules. This challenge is further exacerbated by the large storage requirements for saving the generated 3D representations. Such large storage requirements limit the ability to store a large number of such representations of different human or animal subjects / patients. Such large storage requirements limit the number of transmissions, by the time required for each transmission and / or the system capacity. Also, the efficient transmission of such neural structure representations is limited, as large amounts of data need to be transmitted electronically between devices such as, but not limited to, data stores, servers and desktop computers, laptops, tablets and smartphones, and at least two user devices. For this reason, standard medical image representation formats such as DICOM create 2D slices of such 3D representations, and each 2D slice is stored as a simple bitmap image. An alternative representation that can retain the necessary structural and directional information is the use of parametric representations (e.g., parametric models) that model the prominent structural elements. As described in Example 4 (above), the following network elements can be used to model a set of connected neural structures: ·Termination, ·length, • Crossing, • Relative position of intersection • Types of intersections, and • Density of each network connection.

[0164] Therefore, the representation of some fine structures can be replaced with a predetermined number of parameters using a mapping process, an example of which is shown in Example 4. While such modeling is known to lose fidelity, not all clinical and research applications require high fidelity. For example, if a researcher is investigating the ability of a particular drug to prevent further deterioration of frontal lobe neural connectivity due to dementia, or the effects of another drug such as a drug for Alzheimer's disease, Parkinson's disease, or MS, he / she does not need a complete DTI representation of the entire brain to track the establishment of such effectiveness in the course of administering the particular drug therapy. This parametric representation of complex DTIs can be considered irreversible data compression because the amount of information required to represent specific structural information in the brain is reduced to a finite set of parameters. Storing and transmitting parameterized representations of neural structures is more efficient than representing complete DTI information. Furthermore, the irreversible compression can be slightly or moderately adjacent to the region of interest and can be further compressed from the region of interest. This can be expressed by using a series of parametric models of varying complexity at different distances from the region of interest to reduce the file size required to store DTI information (or the DWI information mentioned above, which is also related to DWI). This method is also similar to estimating the network topology of a neural structure using a restricted set of acceptable topological elements.

[0165] In at least one embodiment, at least one extension plate is used when a larger fiber network has a primary network pattern larger than that of the support plate in its primary arrangement. In these cases, one or more extension plates are used together with the support plate to construct a larger fiber network, and then the network can be physically manipulated through a secondary processing step to position the desired / intended fiber network in a desired 3D pattern that conforms to the support plate (e.g., plate 18) for placement in the external housing. The shape of the fiber network is fixed in the final arrangement. The support plate is then placed in the external housing of the phantom together with the fiber network.

[0166] The applicant's teachings described herein are accompanied by various embodiments for illustrative purposes; however, since the embodiments described herein are intended to be examples, the applicant's teachings are not intended to be limited to such embodiments. Rather, the applicant's teachings described and illustrated herein encompass a variety of alternatives, modifications, and equivalents without departing from the embodiments described herein, the general scope of which is defined in the appended claims. For example, different shapes and sizes may be used for the support column housing, isotropic diffusion module, spacer, and perfusion diffusion module, as well as the phantom external housing. Furthermore, the phantom external housing constructed according to the teachings herein may be made using cylinders of different diameters and alternative shapes to represent different physiological structures, such as the head, torso, or part or section of the spine of a human or other type of animal such as a dog, cat, or horse.

Claims

1. A method for creating an anisotropic spread network module for a phantom, the method being: (a) Define a network pattern and position network elements within the network pattern that include a termination, at least one fiber edge, optionally at least one bifurcation, and optionally at least one intersection, (b) Defining the relative positions of the network elements and the connectivity between the network elements, (c) The intersections between the network elements are defined as one of the following: a contact point, a partially interwoven intersection, and a fully interwoven intersection. (d) Optionally, define relative emphasis between at least two fiber edges connected via bifurcation or crossing, (e) Using scaffolding elements placed on a support plate, define the position of network elements that optionally include at least one isotropic diffusion module, (f) Using fiber material to create the network model, the origin position for starting the assembly of the network pattern is defined using one of the scaffolding elements placed on the support plate, (g) Constructing a fiber network by attaching a desired fiber material to the scaffolding element that defines the origin position, weaving at least one strand of the fiber material around one or more of the scaffolding elements according to a weaving procedure and a network pattern, thereby forming the anisotropic diffusion network module, Methods that include...

2. The method according to claim 1, wherein the fiber network has intersections greater than 0 degrees and narrower than 180 degrees.

3. The method according to any one of claims 1 to 2, further comprising attaching the scaffolding element and the fiber network to the inner surface of the phantom together with the support plate.

4. The method according to any one of claims 1 to 3, wherein the anisotropic diffusion network module is constructed to simulate the diffusion properties of a natural physiological structure.

5. The method according to claim 4, wherein the fiber material is woven around the scaffolding element to form a diffusion network having diffusion properties that mimic the natural physiological structure during MR imaging.

6. The method according to claim 4 or 5, wherein the natural physiological structure being modeled is the corticospinal tract or the corpus callosum.

7. The method according to any one of claims 1 to 6, wherein the fiber material is a composite fiber material comprising a polymer rod covered with a soluble material, and the method comprises weaving strands of the fiber material around one or more of the scaffolding elements before dissolving the soluble material.

8. The method according to any one of claims 1 to 7, wherein constructing the fiber network includes generating a first arrangement in which the fibers are spaced apart from each other in the Z direction.

9. The method according to claim 8, further comprising submerging the fiber network in water to dissolve the soluble material, and optionally heating the water to about 30 to 40 degrees Celsius.

10. The method according to claim 9, wherein the method comprises dissolving the soluble material and then folding the fibers into a second arrangement.

11. The method according to claim 10, wherein the method comprises, after folding the fibers, applying a covering to the fiber network, applying tension to the fiber network, and / or moving the ends of the fiber network to generate a final arrangement for the fiber network.

12. The method according to claim 1, comprising constructing two fiber networks using the same weaving pattern but with different fiber materials used, wherein the fiber material for each of the fiber networks has different dimensions to simulate different degrees of health.

13. A method for constructing a parametric model for representing DTI information of a neural structure, wherein the method is Modeling a set of connected neural structures by using a mapping process based on steps (a) to (c) of claim 1 to create the parametric model by defining terminals, edges having length, crossings, relative positions of crossings, types of crossings, and the density of each network connection in order to represent the neural structure, Saving the aforementioned parametric model, Using the parametric model to reduce the file size required to store DWI or DTI information, Methods that include...

14. The method according to claim 13, further comprising the step of using a series of parametric models having different degrees of complexity at different distances from the region of interest in order to reduce the file size required to store DWI or DTI information.

15. A phantom for use in MR imaging, wherein the phantom is An external housing that defines the internal volume, Displaced within the internal volume of the external housing, at least one support plate having a first surface having a plurality of connection locations for selectively receiving a connector for at least one anisotropic diffusion network module, wherein the connector is removably mated and connected at one or more of the plurality of connection locations on the first surface of the support plate, and the at least one anisotropic diffusion network module is Scaffolding and, A fiber network comprising at least one fiber network, wherein the plurality of connection locations provide the locations of any termination, edge, and node of the at least one fiber network, A support plate, A matrix material contained within the internal volume of the external housing, wherein the matrix material is an aqueous fluid, and during MR imaging, the presence of the aqueous fluid and the direction of fluid molecular diffusion within or through the at least one element are recorded in the MR image. The Phantom, equipped with these features.

16. The phantom according to claim 15, wherein the at least one anisotropic diffusion network module has at least one support column, the at least one element optionally comprises at least one crossbar connector, and the at least one support column is detachably connected to a first surface of the at least one support plate and assembled to support the fiber network.

17. The phantom according to claim 16, wherein the at least one support column comprises a body having a first support column end and a second support column end, the first support column end having a first connector for removable attachment to the first support column, and the second support column end having a second connector for removable attachment to the first surface of the support plate or to the second support column.

18. The phantom according to claim 16 or 17, wherein the at least one crossbar connector comprises at least two end caps and a bar connected to the at least two end caps, each end cap having a recess for receiving the free end of a single support column.

19. The phantom according to any one of claims 15 to 18, wherein the at least one fiber network comprises a fiber having at least one edge coupled to two support columns, the fiber edge having a thickness selected to provide anisotropic diffusion within an element of a desired volume during MR imaging.

20. The phantom according to any one of claims 15 to 19, wherein the at least one fiber network comprises two fiber edges joined at a node.

21. The phantom according to claim 20, wherein the fiber edges have different thicknesses.

22. The phantom according to any one of claims 15 to 21, wherein the at least one fiber network comprises fibers arranged according to a network structure selected based on physiological neural structure, at least two terminations, at least one additional node, at least one edge, and optionally at least one bifurcation.

23. The at least one fiber network comprises a network pattern, the network pattern having network elements including a termination, at least one fiber edge, optionally at least one bifurcated branch, and optionally at least one intersection between network elements. The aforementioned network pattern defines the relative positions of the network elements and the connectivity between the network elements. The aforementioned at least one intersection is defined as one of a contact point, a partially interwoven intersection, and a fully interwoven intersection. Optionally, the network pattern has a defined relative emphasis between at least two fiber edges connected via a bifurcation or crossover. The position of the network element is defined using one or more scaffolding elements placed on a support plate, and optionally includes at least one isotropic diffusion module. The origin position for the network pattern is defined using one of the scaffolding elements placed on the support plate, and the origin position is used to initiate the assembly of the network pattern using fiber material to create a model of the network pattern. The phantom according to claim 15, wherein the fiber material is attached to a scaffolding element that defines the origin position, and at least one strand of the fiber material is woven around one or more of the scaffolding elements according to a weaving procedure and the network pattern in order to form the anisotropic diffusion network module.

24. The phantom according to claim 23, wherein the at least one intersection is greater than 0 degrees and narrower than 180 degrees.

25. The phantom according to any one of claims 23 to 24, wherein one or more scaffolding elements and at least one fiber network are attached to the inner surface of the phantom together with a support plate.

26. The phantom according to any one of claims 23 to 25, wherein the at least one anisotropic diffusion network module is constructed to simulate the diffusion properties of a natural physiological structure.

27. The phantom according to claim 26, wherein the fiber material is woven around one or more scaffolding elements to form a diffusion network having diffusion properties that mimic the natural physiological structure during MR imaging.

28. The phantom according to claim 26 or claim 27, wherein the aforementioned natural physiological structure is the corticospinal tract or the corpus callosum.

29. The phantom according to any one of claims 23 to 28, wherein the fiber material is a composite fiber material comprising polymer rods covered with a soluble material, and the strands of the fiber material are woven around one or more scaffolding elements before the soluble material is dissolved.

30. The phantom according to any one of claims 23 to 29, wherein the at least one fiber network comprises a first arrangement in which the fibers are spaced apart from each other in the Z direction.

31. The phantom according to claim 30, wherein the at least one fiber network is submerged in water to dissolve the soluble material, and optionally the water is heated to about 30-40 degrees Celsius.

32. The phantom according to claim 31, wherein the fibers of the at least one fiber network are folded into a second arrangement after the soluble material has been dissolved.

33. The phantom according to claim 32, wherein after the fibers are folded, a covering is applied to the at least one fiber network, and then the at least one fiber network is stretched and / or the ends of the fiber network are moved to produce a final arrangement for the at least one fiber network.

34. The phantom according to claim 15, wherein the phantom is made with the same weaving pattern but comprises two different fiber networks of fiber materials having different dimensions to simulate different degrees of health.

Images