WO2017009856A1

WO2017009856A1 - Method and system for hyperpolarization of materials used in magnetic resonance imaging

Info

Publication number: WO2017009856A1
Application number: PCT/IL2016/050781
Authority: WO
Inventors: Uri Rapoport; Yoram Cohen
Original assignee: Aspect Imaging Ltd
Current assignee: Aspect Imaging Ltd
Priority date: 2015-07-16
Filing date: 2016-07-17
Publication date: 2017-01-19
Anticipated expiration: 2018-01-16

Abstract

A method for hyperpolarizing a material includes subjecting a material to a first magnetic field for a first duration. The material is subjected to a second magnetic field for a second duration, the first magnetic field and the second magnetic field each having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

Description

METHOD AND SYSTEM FOR HYPERPOLARIZATION OF MATERIALS USED IN MAGNETIC RESONANCE IMAGING

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present invention claims priority to and the benefit of U.S. Provisional Patent Application No. 62/193,135 filed on July 16, 2015, which is incorporated herein in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to hyperpolarization of materials, and particularly to hyperpolarization of materials used in magnetic measuring (e.g., magnetic resonance imaging (MRI)).

BACKGROUND OF THE INVENTION

[0003] Magnetic resonance devices (MRD) include devices that can perform magnetic resonance measurements, for example, magnetic resonance imaging (MRI) (a.k.a. nuclear magnetic resonance imaging (NMRI)). MRI is a magnetic imaging technique that may be used to image, for example, anatomic features of a body of a subject and/or physiological processes in those features. In another example, MRI images may also be used to accurately identify pathologies within a body of the subject, such as a human body and/or a laboratory animal. MRI scanning systems may apply magnetic fields and/or radio frequency signals to the subject to cause an electromagnetic emission in response from the subject. The electromagnetic emission can be the basis for forming the MRI images.

[0004] In some scenarios, MRI's can produce images with a sensitivity that is not sufficient for the purpose of the MRI. For example, low MRI sensitivity may impact oncological diagnoses where the accuracy in identifying cancer cells within a small region of tissue may be critical.

[0005] Hyperpolarized materials may be used as a contrasting agent to improve a soft contrast of MRI images and may be injected into the body of a subject, e.g., just prior to and/or during the MRI imaging. In some processes, hyperpolarized materials, e.g., contrasting agents, may be prepared using highly reactive chemicals, such as persistent radicals, which can be toxic if the material is not filtered prior to administering the contrasting agent to the subject, or patient. One type of contrasting agent, Pyruvic acid is a naturally occurring by-product of glucose breakdown in the human body, and thus when hyperpolarized can be non-toxic. Pyruvic acid can be hyperpolarized and used as a non-toxic, in vivo infusion fluid for the subject during MRI imaging.

[0006] Hyperpolarized materials that are used, for example, as MRI contrasting agents or in other suitable applications, such as in different spectroscopies, can be prepared prior to use. However, once prepared, the hyperpolarized materials may breakdown within time frames on the order of a few seconds to a few minutes, for example, depending on the ambient environment, the type of hyperpolarized material and/or other factors that are known in the art. The hyperpolarized materials may be typically prepared, for example, in reasonable proximity to the location in which the hyperpolarized materials are used to, for example, avoid breakdown of the material prior to use.

[0007] Dynamic nuclear polarization (DNP) is one current method for hyperpolarizing materials. However, a duration of time that it takes for a material to hyperpolarize using DNP can be undesirably long (e.g., on the order of a few hours) and/or the DNP equipment used to prepare the hyperpolarized material can be expensive.

[0008] Another difficulty with DNP is that the hyperpolarized material may be stale by the time the material is introduced to the subject, due to, for example, the long duration it takes to hyperpolarize using DNP and/or the amount of time the hyperpolarized material remains hyperpolarized once created. For example, in a hospital setting, a patient can need to be at the MRI machine at the exact time that the hyperpolarized material is created, for a hyperpolarized material that loses its hyperpolarization within seconds of being created. In hospital settings, getting patients to a particular location at a particular time can be difficult (e.g., due to slow elevators, or unexpected delay in staff availability). In some scenarios it can be difficult to have a patient waiting at the MRI for the hyperpolarized material to finish being created (e.g., a neonate on life support).

[0009] Another method to prepare hyperpolarize materials may include the use of placing together para-hydrogen with a material to cause a chemical reaction, and subjecting the para- hydrogen and the material to magnetic fields. However, this method may not be used to hyperpolarize any material, and particularly may not be used to hyperpolarize pyruvic acid since, for example, para-hydrogen does not typically bond to pyruvic acid. [0010] Another difficulty with current methods for creating hyperpolarized material is that current methods can require manual placement of the material in/out of a magnetic field(s), thus, for example, causing the reproducibility of the hyperpolarization difficult.

Thus, it can be desirable to have an inexpensive device for hyperpolarizing materials. It can be desirable to hyperpolarize materials with a fast speed (e.g., on the order of minutes/seconds). It can be desirable to provide a patient a contrasting agent that is made substantially at the same time interval the patient is having an MRI taken. It can be desirable to have automated hyperpolarization that does not require manual intervention to change magnetic fields surrounding the material. It can be desirable to have fast hyperpolarization of any material.

SUMMARY OF THE INVENTION

[0011] One advantage of the invention may include that it provides an inexpensive method/device for hyperpolarizing materials. Another advantage of the invention can include hyperpolarization of materials with a fast speed (e.g., on the order of minutes/seconds). Another advantage of the invention can be providing a patient a contrasting agent that is made substantially at the same time interval the patient is having an MRI taken. Another advantage of the invention can be automated hyperpolarization that does not require manual intervention to change magnetic fields surrounding the material.

[0012] There is thus provided, in accordance with some embodiments of the present invention, a method for hyperpolarizing a material, the method including subjecting a material to a first magnetic field for a first duration. The material is subjected to a second magnetic field for a second duration, the first magnetic field and the second magnetic field each having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

[0013] In accordance with some embodiments of the present invention, subjecting the material to the first magnetic field further includes positioning the material within a zero gauss chamber.

[0014] In accordance with some embodiments of the present invention, subjecting the material to a second magnetic field further includes generating the second magnetic field within the zero gauss chamber. [0015] In accordance with some embodiments of the present invention, the first magnetic field is less than or equal to 100 nanoTesla.

[0016] In accordance with some embodiments of the present invention, the second magnetic field varies in magnitude between 100 nanoTesla and 50 microTesla.

[0017] In accordance with some embodiments of the present invention, the second magnetic field includes a magnitude, direction, or any combination thereof that varies over time.

[0018] In accordance with some embodiments of the present invention, the varying magnitude, direction, or any combination thereof of the second magnetic field is based on a predefined waveform.

[0019] In accordance with some embodiments of the present invention, the predefined waveform is based on a type of the material.

[0020] In accordance with some embodiments of the present invention, subjecting the material to the first magnetic field and the second magnetic field further includes flowing the material through a first portion of a conduit, the first portion of the conduit having the first magnetic field, and flowing the material through a second portion of the conduit, the second portion on the conduit having the second magnetic field.

[0021] There is further provided, in accordance with some embodiments of the present invention, a system for hyperpolarizing a material including a controller, a zero gauss chamber formed from at least one layer of mu-metal, the zero gauss chamber having a first magnetic field within the zero gauss chamber, and a coil positioned within the zero gauss chamber. The controller is coupled to a coil, to cause the coil to generate a second magnetic field within the zero gauss chamber, the second magnetic field having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

[0022] In accordance with some embodiments of the present invention, the controller causes the coil to generate the second magnetic field over a time duration with a varying magnitude, direction, or any combination thereof.

[0023] There is further provided, in accordance with some embodiments of the present invention, a system for hyperpolarizing a material including a flow generator, a zero gauss chamber formed from at least one layer of mu-metal, the zero gauss chamber having a first magnetic field within the zero gauss chamber, and a conduit having a first section that is positioned within the zero gauss chamber and a second section that is positioned outside of the zero gauss chamber. The flow generator is coupled to the conduit, the flow generator causing the material to flow through the first magnetic field in a first time duration and through a second magnetic field in a second time duration, the second magnetic field having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

[0024] In accordance with some embodiments of the present invention, the second section of the conduit includes a helical shape.

[0025] In accordance with some embodiments of the present invention, the first time duration and the second time duration are controlled by varying a flow rate of the fluid in the conduit.

[0026] In accordance with some embodiments of the present invention, the system further includes a coil positioned within the zero gauss chamber and a controller coupled to the coil, to cause the coil to generate the second magnetic field within the zero gauss chamber.

[0027] In accordance with some embodiments of the present invention, the system further includes a coil positioned near the second section of the conduit and a controller coupled to the coil, to cause the coil to generate the second magnetic field in the second section of the conduit.

[0028] In accordance with some embodiments of the present invention, the material is an infusion fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order for the present invention, to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0030] Fig. 1A illustrates a zero-gauss chamber (ZGC) encased by an inner shell including layers of mu-metal and an outer shell of a standard metal, in accordance with some embodiments of the present invention;

[0031] Fig. IB illustrates a cross-section of a zero-gauss chamber (ZGC), in accordance with some embodiments of the present invention;

[0032] Fig. 1C illustrates a system for hyperpolarizing material in a zero-gauss chamber (ZGC) including a receptacle and a coil, in accordance with some embodiments of the present invention; [0033] Fig. 2 is a graph of a linearly varying magnetic field time sequence causing material to hyperpolarize, in accordance with some embodiments of the present invention;

[0034] Fig. 3 is a graph of a non-linearly varying magnetic field time sequence causing material to hyperpolarize, in accordance with some embodiments of the present invention;

[0035] Fig. 4A schematically illustrates a system for hyperpolarizing a fluid, in accordance with some embodiments of the present invention.

[0036] Fig. 4B is graph of a magnetic field time sequence causing fluid to hyperpolarize while traversing a conduit, in accordance with some embodiments of the present invention;

[0037] Fig. 5 schematically illustrates a system for passively hyperpolarizing a fluid, in accordance with some embodiments of the present invention;

[0038] Fig. 6 schematically illustrates an automated system to hyperpolarize an infusion fluid prior to administering to a subject, in accordance with some embodiments of the present invention; and

[0039] Fig. 7 is a flowchart depicting a method for hyperpolarizing a material, in accordance with some embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0040] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

[0041] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer' s registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, us of the conjunction "or" as used herein is to be understood as inclusive (any or all of the stated options).

[0042] Embodiments of the present invention described herein include methods and systems for the hyperpolarization of materials. The materials to be hyperpolarized may be placed in a first magnetic field for a first duration (e.g., typically a zero gauss magnetic field < 100 nT for 500 ms duration) and in a second magnetic field for a second duration (e.g., a constant or varying field between HOnT and 50μΤ for 2 sec duration), where the first and the second magnetic fields cause the material to hyperpolarize. In some embodiments, the second magnetic field may be used to subject the material to a slow linearly increasing the magnetic field to cause the material to hyperpolarize. In some embodiments, the material may be subject to a non-linear magnetic field to cause the material to hyperpolarize.

[0043] In some embodiments of the present invention, a hyperpolarization of materials such as infusion fluids, for example, may be used in a body of a subject undergoing MRI scans so as to improve a soft contrast of the MRI images of the subject. Hyperpolarized infusion fluids may be used as contrasting agents during MRI scans to further improve the soft tissue contrast in magnetic resonance imaging (MRI) images of the subject by, for example, 100,000 times.

[0044] Fig. 1A illustrates a zero-gauss chamber (ZGC) 120 encased by an inner shell including layers of mu-metal 130 and a metal outer shell 140, in accordance with some embodiments of the present invention. The ZGC 120 may be formed from at least one mu- metal layer. The at least one mu-metal layer may be used to absorb magnetic energy within the chamber. The ZGC 120 may be a magnetic shield made from mu -Metal to provide a chamber isolated from the earth's natural magnetic field (e.g., 50 μΤ). The magnitude of the magnetic field within the ZGC 120 may be less than or equal to 100 nano-Teslas (nT). Any suitable material may be used for magnetic shielding.

[0045] Although Fig. 1A shows the inner shell of the ZGC 120 including three layers of mu- metal 130, any number of mu-metal layers may be used. Any suitable metal as is currently known in the art for making zero gauss chambers may be used for the outer shell 140 in forming the ZGC 120.

[0046] Fig. IB illustrates a cross-section of ZGC 120, in accordance with some embodiments of the present invention. Fig. IB shows the cross-section of the ZGC 120 as a circular shape. In various embodiments, the ZGC 120 is square, rectangle, triangle, or any shape.

[0047] Fig. 1C illustrates a system 100 for hyperpolarizing material in the ZGC 120 including a receptacle 160 and a coil 150, in accordance with some embodiments of the present invention. The ZGC 120 has a magnetic field (e.g., a first magnetic field) therein. In some embodiments, the first magnetic field is less than 100 nT. The coil 150 may be positioned within the ZGC 120 so as to generate a magnetic field (e.g., a second magnetic field) within the ZGC 120. The second magnetic field can be based on a type of material to be hyperpolarized. In Fig. 1C, the coil 150 may include a solenoid coil, which is coiled around the receptacle 160. The coil 150 may be formed from materials, such as copper, for example. The receptacle 160 may hold, for example, the material to be hyperpolarized.

[0048] A controller 110 such as a signal generator may be coupled to the coil 150 via a cable 170. The cable 170 may include, for example, a shielded two-wire, noise reducing cable, the first wire of which may be used for conducting the electrical current from the controller 110 to the coil 150 as shown connected to the coil 150 in Fig. 1C. A second wire may be connected to the shield of the two- wire cable and to the inner shell of the ZGC 120 including the at least one mu-metal layer. The second wire may be used as a noise-reducing, artificial ground. The cable 170 may include a coaxial cable for electromagnetic shielding. The cable 170 may include a twisted pair cable for further reducing electromagnetic induction between the first and second wires, e.g., cross-talk. Any magnetic noise, or ambient induction, generated within the ZGC 120 can be larger than the zero gauss state fields on the order of 100 nT. Hence, magnetic noise reducing strategies may be used such as deploying the cabling as described above.

[0049] In some embodiments of the present invention, the coil 150 may be used for producing a low-intensity magnetic field in ZGC 120. The controller 110 coupled to the coils 150 may be used drive current into the coil 150 so as produce the second magnetic field, e.g., a magnetic field with a magnitude up to about 50 μΤ (micro-Teslas) in ZGC 120. When the current in the coil is zero, the magnitude of the magnetic field in the chamber is the first magnetic field (e.g., may be less than or equal to 100 nT). [0050] Controller 110 may generate and/or receive as an input a predefined waveform such as a predefined current waveform. The predefined current waveform when applied to coil 150 may generate a magnetic field in ZGC 120 with a varying magnitude, direction, or any combination thereof. The varying magnetic field based on the predefined current waveform may then be used to hyperpolarize material place in receptacle 160. In other embodiments, receptacle 160 may include a conduit through which the material such as an infusion fluid may flow.

[0051] In some embodiments of the present invention, the predefined waveform used to hyperpolarize the material may be based on the type of material to be hyperpolarized.

[0052] In some embodiments of the present invention, the material to be hyperpolarized may be placed receptacle 160 in Fig. 1C. Receptacle 160 may include a test tube or a capsule. System 100 may use a conveyor belt or a robotic arm to move the capsule through the magnetic field in ZGC 120 generated by coil 150 positioned in ZGC 120.

[0053] Fig. 2 is a graph of a linearly varying magnetic field time sequence causing material to hyperpolarize, in accordance with some embodiments of the present invention. The material placed in the receptacle 160, for example, may be subject to magnetic field states sequenced with the time durations denoted (a)-(e) as shown in Fig. 2. The controller 110 may generate a current applied to the coil 150 to produce a starting field value in region (a) of 50 μΤ. The current may be ramped down so as to produce a fast linear drop in the magnitude of the magnetic field over a time period of 50 mS as shown in region (b) from 50 μΤ to 100 nT. The zero gauss magnetic field with a magnitude of 100 nT or less may be maintained for a period of 500 mS as in region (c). The predefined current waveform from the controller 110 may be slowly ramped to produce a linear magnetic field as shown in region (d) over a duration of 2 seconds from 100 nT up to 50 μΤ as in region (e). The material in the receptacle 160 is hyperpolarized when subject to the time varying magnetic field sequence shown in Fig. 2.

[0054] In some embodiments of the present invention, the magnetic field profile as shown in Fig. 2 may be calculated, for example, using quantum mechanical models. Any suitable model and/or a different process modeling may be used to generate a magnetic field time sequence that causes the material to hyperpolarize.

[0055] Fig. 3 is a graph of a non-linearly varying magnetic field time sequence causing material to hyperpolarize, in accordance with some embodiments of the present invention. The varying magnetic field of Fig. 3 generated by applying a predefined waveform to the coil 150 is similar to that shown in Fig. 2 except that in region (d), the magnetic field may be a non-linear pulse waveform in transitioning from 100 nT to 50 μΤ. In some embodiments, the shape of the non-linear pulsed magnetic field as well as the curvature of the pulses may be changed according to the type of material so as to produce useful variations of the hyperpolarized material. Applying the magnetic field time sequences such as in Figs. 2-3 to materials to cause hyperpolarization of the material may also be referred to herein as field cycling.

[0056] Fig. 4A schematically illustrates a system 400 for hyperpolarizing a fluid 200, in accordance with some embodiments of the present invention. The system 400 includes a conduit 405, a flow generator 300, a coil 410, and the ZGC 120. A first section of the conduit 405 may be positioned within the ZGC 120 and a second section may be positioned outside of the ZGC 120. The coil 410 may be coiled around, or positioned near the second portion of the conduit 405 external to the ZGC 120 and may be driven by a controller (not shown in Fig. 4 A), such as the controller 110 in Fig. 1C, so as to subject the fluid 200 flowing in the second portion of the conduit to the second magnetic field generated by the coil 410.

[0057] The flow generator 300 may be used to control the flow rate of the fluid 200 in the conduit 405 such that the fluid 200 may be subject a zero gauss magnetic field in the ZGC 120 (e.g., 100 nT or less), or the first magnetic field in a first time duration, and a second magnetic field in the second portion of the conduit in a second time duration.

[0058] In some embodiments of the present invention, more than one flow generators may be used such as, for example, a second flow generator 350 as shown in Fig. 4A

[0059] Fig. 4B is graph of a magnetic field time sequence causing the fluid 200 to hyperpolarize while traversing the conduit 405, in accordance with some embodiments of the present invention. The coil 410 coiled around, or placed near to the second section of the conduit 405 exiting the ZGC 120 may be used to generate the second magnetic field. Initially the fluid outside of the ZGC 120 is subject to a magnetic field strength of approximately 50 μΤ, for example, in region (a). The fluid passing into the ZGC 120 is subject to a linear drop in the magnetic field from 50 μΤ to 100 nT for a time duration of 50 ms in region (b). The fluid remains in a magnetic field of 100 nT for a time duration of 500 ms in region (c). The fluid 200 exits the ZGC 120 where the coil 160 is positioned near the second section of the conduit 405 and used to generate a linearly increasing magnetic field from 100 nT to 50 μΤ for a duration of 2 seconds in region (d). The fluid is subject to a magnetic field of 50 μΤ in region (e). [0060] Changing the flow rate of the fluid flowing in the conduit by using a flow generator, changing the predefined current waveform from the controller applied to the coil 410 or any combination thereof, may be used to subject the fluid 200 to any suitable combination of magnetic fields (e.g, magnitude and direction) for any suitable time durations, which cause the fluid to hyperpolarize.

[0061] In some embodiments of the present invention, the coil 410 may not be present or may not operate. The fluid may be hyperpolarized fluids without having to generate a low-intensity magnetic field using a current-driven coil, for example. The material or fluid in the second portion of the conduit exiting the ZGC 120 may be subject to a step in the magnitude of magnetic field from 100 nT or less inside the ZGC 120 to 50 μΤ in the second portion outside of the ZGC 120. The flow generator may be used to control the flow rate such that the fluid may be hyperpolarized when subject to a slowly varying change in the two magnetic field states as the fluid slowly moves from inside the ZGC 120 to outside of the ZGC 120.

[0062] In some embodiments of the present invention, the coil 410 may be coiled around the first portion of the conduit (e.g., as in Fig. 1C) such that the fluid is subject to both the first and second magnetic fields within the ZGC 120. The fluid in the second portion of the conduit may be subject to a magnetic field of about 50 μΤ.

[0063] Fig. 5 schematically illustrates a system 500 for passively hyperpolarizing fluid 200, in accordance with some embodiments of the present invention. The system 500 may include the flow generator 300, the ZGC 120, and the conduit 405 with a first portion in the ZGC 120 coupled to a helical-shaped conduit 505 in the second section, or portion, outside of the ZGC 120. The flow generator 300 may be used to control the flow of fluid 200 in the first section of the conduit 405 and in the second section of the helical-shaped conduit 505. The fluid 200 may be subject a zero gauss magnetic field (e.g., 100 nT or less) over a first time duration and a second magnetic field (e.g., 50 μΤ) in a second time duration. The helical- shaped conduit 505 may include any number of loop winding in any suitable shape and/or configuration.

[0064] In some embodiments of the present invention, the coil 410 may be coiled around the helical shaped conduit to control the second magnetic field in the second portion of the conduit. In some embodiments, the coil 410 may be coiled around the first portion of the conduit in the ZGC 120.

[0065] Fig. 6 schematically illustrates an automated system 650 to hyperpolarize an infusion fluid 605 prior to administering to a subject 620, in accordance with some embodiments of the present invention. The system 650 may include the infusion fluid 605 that may be hyperpolarized in a hyperpolarization system 610. The system 610 may be implemented, for example, by the system 400 as shown in Fig 4A. The subject 620 may be infused with the hyperpolarized fluid 605 through an infusion tube 615 while being imaged in a magnetic resonance imaging (MRI) system 600. The MRI system 600 may also be referred to as a magnetic resonance imaging device (MRD) 600.

[0066] The system 610 may cause the infusion fluid to hyperpolarize by implementing the steps of any suitable chemical process and/or by subjecting the infusion fluid to any suitable magnetic field time sequence in a zero gauss chamber. A breakdown of the fluid may be prevented by administering the fluid 605 to the subject 620 upon hyperpolarizing the fluid.

[0067] Flow generators may be used in the system 650 to cause the infusion fluid 605 to flow in the system 650. Non-magnetic infusion pumps may be used so as not to induce a breakdown in the infusion fluid after hyperpolarization

[0068] In some embodiments of the present invention, the system 650 may be used for cancer cell detection and mapping the location of cancer cells in the subject 620.

[0069] In some embodiments of the present invention, the infusion fluid 605 may include a metabolic marker.

[0070] In some embodiments of the present invention, the system 600 in Fig. 6 when implemented by the system 400 may be used to monitor physical and chemical phenomena that occur during a plug-flow reaction. The different components of the system 400 (e.g., flow generators) may be configured to produce plug-flow conditions at one or more points in the fluid cycle.

[0071] In some embodiments of the present invention, the MRD 600 may be used to measure the resonance properties of the infusion fluid in the subject 620.

[0072] In some embodiments of the present invention, the infusion fluid 605 may flow through the ZGC 120 after exiting the subject 620.

[0073] Fig. 7 is a flowchart depicting a method 700 for hyperpolarizing a material, in accordance with some embodiments of the present invention. The method 200 includes a subjecting 705 a material to a first magnetic field for a first duration. The method 200 includes subjecting 710 the material to a second magnetic field for a second duration, the first magnetic field and the second magnetic field each having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field. [0074] In some embodiment of the present invention, subjecting the material to the first magnetic field (step 705) and the second magnetic field (step 710) further includes flowing the material through a first portion of a conduit (e.g., conduit 405), the first portion of the conduit having the first magnetic field, and flowing the material through a second portion of the conduit, the second portion on the conduit having the second magnetic field.

[0075] In some embodiments of the present invention, the system 400 may be used to produce hyperpolarized toxin detection fluid. The hyperpolarized toxin detection fluid may be introduced into the water supply. The MRD 600 may be used detect dangerous contaminants in the water supply by identifying changes in contrast in MRI images enhanced by the hyperpolarized toxin detection fluid across different regions of the water supply.

[0076] It should be understood with respect to any flowchart referenced herein that the division of the illustrated method into discrete operations represented by blocks of the flowchart has been selected for convenience and clarity only. Alternative division of the illustrated method into discrete operations is possible with equivalent results. Such alternative division of the illustrated method into discrete operations should be understood as representing other embodiments of the illustrated method.

[0077] Similarly, it should be understood that, unless indicated otherwise, the illustrated order of execution of the operations represented by blocks of any flowchart referenced herein has been selected for convenience and clarity only. Operations of the illustrated method may be executed in an alternative order, or concurrently, with equivalent results. Such reordering of operations of the illustrated method should be understood as representing other embodiments of the illustrated method.

[0078] Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0079] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A method for hyperpolarizing a material, the method comprising:

subjecting a material to a first magnetic field for a first duration; and

subjecting the material to a second magnetic field for a second duration, the first magnetic field and the second magnetic field each having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

2. The method of claim 1 , wherein subjecting the material to the first magnetic field further comprises positioning the material within a zero gauss chamber.

3. The method of claim 2, wherein subjecting the material to a second magnetic field further comprises generating the second magnetic field within the zero gauss chamber.

4. The method of claim 1 , wherein the first magnetic field is less than or equal to 100 nanoTesla.

5. The method of claim 1 , wherein the second magnetic field varies in magnitude between 100 nanoTesla and 50 microTesla.

6. The method of claim 1 , wherein the second magnetic field comprises a magnitude, direction, or any combination thereof that varies over time.

7. The method of claim 6, wherein the varying magnitude, direction, or any combination thereof of the second magnetic field is based on a predefined waveform.

8. The method of claim 7, wherein the predefined waveform is based on a type of the material.

9. The method of claim 1 wherein subjecting the material to the first magnetic field and the second magnetic field further comprises: flowing the material through a first portion of a conduit, the first portion of the conduit having the first magnetic field; and

flowing the material through a second portion of the conduit, the second portion on the conduit having the second magnetic field.

10. A system for hyperpolarizing a material, the system comprising:

a zero gauss chamber formed from at least one layer of mu-metal, the zero gauss chamber having a first magnetic field within the zero gauss chamber;

a coil positioned within the zero gauss chamber; and

a controller coupled to a coil, to cause the coil to generate a second magnetic field within the zero gauss chamber, the second magnetic field having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

11. The system of claim 10, wherein the controller causes the coil to generate the second magnetic field over a time duration with a varying magnitude, direction, or any combination thereof.

12. The system of claim 1 1, wherein the varying magnitude, direction, or any combination thereof is based on a predefined waveform.

13. The system of claim 12, wherein the predefined waveform is based on a type of the material.

14. A system for hyperpolarizing a material, the system comprising:

a conduit having a first section that is positioned within the zero gauss chamber and a second section that is positioned outside of the zero gauss chamber; and

a flow generator coupled to the conduit, the flow generator causing the material to flow through the first magnetic field in a first time duration and through a second magnetic field in a second time duration, the second magnetic field having a magnitude and direction to cause the material to hyperpolarize, the second magnetic field being different than the first magnetic field.

15. The system according to claim 14, wherein the second section of the conduit comprises a helical shape.

16. The system according to claim 14, wherein the first time duration and the second time duration are controlled by varying a flow rate of the fluid in the conduit.

17. The system according to claim 14, further comprising a coil positioned within the zero gauss chamber and a controller coupled to the coil, to cause the coil to generate the second magnetic field within the zero gauss chamber.

18. The system according to claim 14, further comprising a coil positioned near the second section of the conduit and a controller coupled to the coil, to cause the coil to generate the second magnetic field in the second section of the conduit.

19. The system according to claim 14, wherein the material is an infusion fluid.