WO2024191654A1 - Magnetic field control of sabre hyperpolarized molecules for processing and administration - Google Patents

Abstract

In one aspect, the disclosure relates to a method for conserving hyperpolarization in a hyperpolarized molecule undergoing at least one processing step, the method including conducting the at least one processing step in a magnetic field having a magnetic field strength higher than the magnetic field strength of Earth. In an aspect, prior to the at least one processing step but following hyperpolarization, the molecule can be transferred into a processing magnetic field in an adiabatic manner. In still another aspect, following the processing step, the molecule can be transferred into a signal detection magnetic field in an adiabatic manner. Prior to performing the method, the hyperpolarized molecule can be produced using signal amplification by reversible exchange (SABRE). Also disclosed herein are hyperpolarized molecules prepared by the disclosed methods, contrast agents comprising the same, and methods for diagnosing a disease or monitoring the progress of disease treatment using the same.

Description

MAGNETIC FIELD CONTROL OF SABRE HYPERPOLARIZED MOLECULES FOR PROCESSING AND ADMINISTRATION

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/489,431 filed on March 10, 2023, which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under grant numbers EB029829 and MH129007 awarded by the National Institutes of Health. The government has certain rights in the invention.

BACKGROUND

[0003] Today's clinical approach to molecular imaging uses Positron Emission Tomography (PET). PET uses radioactive tracers that are associated with significant radiation doses and PET requires a large infrastructure to produce radiolabels, and detection occurs in expensive scanners. Furthermore, the radiation dose required does not permit frequent follow-up scans or longitudinal studies. Further of note is that PET signals are not inherently sensitive to molecular transformations. In contrast, hyperpolarization uses endogenous molecules, free of ionizing radiation, which directly report on metabolic transformations because the hyperpolarized MRI signal changes its frequency upon a change in molecular structure.

[0004] Hyperpolarized imaging as it is currently carried out has significant limitations, as well. Hyperpolarized MRI is currently in ~30 clinical trials and uses the so-called dissolution Dynamic Nuclear Polarization (d-DNP) approach. d-DNP is relatively expensive and slow in that a d-DNP polarizer costs well above $1M and it can only produce a hyperpolarization dose about once an hour.

[0005] Signal Amplification by Reversible Exchange (SABRE) is another method for hyperpolarizing nuclear spin states in molecules. SABRE can enhance magnetic resonance (MR) and magnetic resonance imaging (MRI) signals by many orders of magnitude. SABRE hyperpolarized molecules with associated strongly enhanced MR and MRI signals have a large scope of applications ranging from chemical analysis to medical imaging. Important fields of application include, but are not limited to, plant imaging, complex-mixture analysis, microscopic cell imaging, spectroscopy, medical molecular imaging, pre-clinical (i.e. animal) spectroscopy and imaging, biophysics, molecular structure elucidation, and any other application that MR and MRI are used for today. SABRE can provide continuous hyperpolarization and costs significantly less than other hyperpolarization techniques, as well as requiring less complex equipment than d-DNP techniques. However, current SABRE methods result in loss of hyperpolarization between the time of production of hyperpolarized molecules and deployment and/or measurement of the resulting MR signals.

[0006] Despite advances in hyperpolarization research, there is still a scarcity of methods for conservation of hyperpolarization in samples between the time of production and use, including reduction of hyperpolarization loss during processing steps prior to clinical use of hyperpolarized molecules. These needs and other needs are satisfied by the present disclosure.

SUMMARY

[0007] In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to a method for conserving hyperpolarization in a hyperpolarized molecule undergoing at least one processing step, the method including conducting the at least one processing step in a magnetic field having a magnetic field strength higher than the magnetic field strength of Earth. In a further aspect, the at least one processing step can include depressurization, precipitation, filtration, redissolution, performing at least one chemical reaction, performing a phase transfer process, or any combination thereof. In an aspect, prior to the at least one processing step but following hyperpolarization, the molecule can be transferred into a processing magnetic field in an adiabatic manner. In still another aspect, following the at least one processing step, the molecule can be transferred into a signal detection magnetic field in an adiabatic manner. In an aspect, prior to performing the method, the hyperpolarized molecule can be produced using signal amplification by reversible exchange (SABRE), hydrogenation, side-arm hydrogenation, or any other method useful for producing a hyperpolarized molecule. Also disclosed herein are hyperpolarized molecules prepared by the disclosed methods, contrast agents comprising the same, and methods for diagnosing a disease or monitoring the progress of disease treatment using the same.

[0008] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0010] FIG. 1 shows a process diagram for an exemplary method as disclosed herein.

[0011] FIG. 2 is an illustration of polarization transfer from an initial field Bj into a perpendicular field Bf For adiabatic polarization transfer the rate of change of the angle dO/dt has to be slower than the Larmor precession frequency co.

[0012] FIG. 3 is a comparative plot of the Larmor frequency co and the rate of change for the angle 0 as a function of polarization transfer time. The parameters used in this simulation are: initial field, Bj = 10k G, final field, Bf = 1 G, gyromagnetic ratio y = 430 Hz/G, sample velocity, v = 200 cm/s, exponential magnetic field gradient EG = 2/cm.

[0013] FIGs. 4A-4F show In vivo spectra acquired on two female rats using a dynamic spectroscopy sequence and a different field of view on the liver (FIGs. 4A-4C) and kidneys (FIGs. 4D-4F). FIGs. 4A and 4D: Summed spectra of the complete dynamic spectroscopy acquisition. [B, E] Spectra overlay of the dynamic spectroscopy acquisition with lactate, alanine, and pyruvate integration regions highlighted. FIGs. 4C and 4F: Plot of the integrated acquisition for pyruvate, lactate, and alanine using the spectra shown in FIGs. 4B and 4E. The spectra in this temporal series are acquired with a 20-degree flip angle.

[0014] FIGs. 5A-5F show chemical imaging spectroscopy (CSI) experiments performed on two separate animals (shown in separate rows) on two different field of views (liver, FIGs. 5A-5C; kidney, FIGs. 5D-5F). FIGs. 5A and 5D: 8 x 8 array of the 64 spectra acquired in the respective CSI experiments. FIGs. 5B and 5E: Integration of the peaks shown in the spectra to obtain a heat map overlayed on top of the center anatomical slice of imaged region. FIGs. 5C and 5F: Linearly extrapolated heat map (32 * 32) for visualization of the CSI results. CSI results are acquired linearly in a 8x8 matrix using a 20-degree flip angle.

[0015] FIGs. 6A-6C show in vivo spectra acquired on one Wistar female rat using a dynamic spectroscopy sequence. FIG. 6A: Summed spectra of the complete dynamic spectroscopy acquisition. FIG. 6B: Spectra overlay of the dynamic spectroscopy acquisition with lactate, alanine, and pyruvate integration regions highlighted. FIG. 6C: Plot of the integrated acquisition for pyruvate, lactate, and alanine using the spectra shown in FIG. 6B. The spectra in this temporal series are acquired with a 20-degree flip angle and a 2s delay between acquisitions.

[0016] FIGs. 7A-7D show an exemplary experimental procedure of MRI in vivo studies. FIG. 7A: SABRE hyperpolarization takes place inside of mu-magnetic shields allowing for a PTF of 0.3 pT. While inside of the shield’s parahydrogen is bubbled for 90 seconds allowing for polarization buildup. FIG. 7B: The sample is transferred to a 1 T Halbach array for depressurization and ejection into a pre-filled saline syringe, taking 10 seconds. FIG. 7C: After ejection the sample is moved across the room and attached to the catheter for injection, this takes a variable amount of time. FIG. 7D: After injection a two-minute scan is applied with a 20° pulse and repetition time of 2 seconds.

[0017] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

DETAILED DESCRIPTION

[0018] Disclosed herein is method for conserving hyperpolarization in a hyperpolarized molecule undergoing at least one processing step, the method including the step of conducting the at least one processing step in a processing magnetic field having a magnetic field strength higher than the magnetic field strength of Earth. In some aspects, the molecule can be a drug ora metabolite. In another aspect, the at least one processing step can be depressurization, precipitation, filtration, redissolution, performing at least one chemical reaction, performing a phase transfer process, or any combination thereof. [0019] In another aspect, following the at least one processing step, the molecule can be transferred to a signal detection magnetic field in an adiabatic matter, wherein the condition for adiabaticity can be described by Y-B_eff » d<t>/dt wherein y is a gyromagnetic ratio of at least one hyperpolarized nucleus in the molecule; wherein B_eff is an effective magnetic field acting on the at least one hyperpolarized nucleus; and wherein diji/dT is a derivative of the phase of a hyperpolarized spin state of the at least one hyperpolarized nucleus with respect to time.

[0020] In another aspect, following hyperpolarization but prior to performing the at least one processing step, the molecule can be transferred to the processing magnetic field in an adiabatic manner, wherein the condition for adiabaticity is as described above.

[0021] Further in this aspect, B_eff can include a main magnetic field B_o, an applied oscillating field Bo, a local field on a molecular scale, or any combination thereof, while the local field on a molecular scale can be a J coupling, a dipolar interaction, or any combination thereof. In any of the foregoing aspects, the at least one hyperpolarized nucleus can be ¹H, ¹⁵N, ¹³C, or any combination thereof.

[0022] In another aspect, the processing and signal detection magnetic fields can have an axial or crosswise direction. In one aspect, the processing magnetic field, the signal detection magnetic field, or both have a strength of from about 100 pT to about 3 T, or of about 100, 200, 300, 400, 500, 600, 700, 800, or 900 pT, or about 1 , 50, 100, 200, 300, 400, 500, 600, 700, 800, or 900 mT, or about 1 , 2, or 3 T, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In some aspects, the processing and signal detection magnetic fields can be generated by an electromagnet, a Halbach array, another permanent magnet system, or any combination thereof.

[0023] In some aspects, the hyperpolarized molecule can be introduced into the processing magnetic field, the signal detection magnetic field, or both using a second magnetic field such as, for example, a pulsed magnetic field or a static magnetic field. In another aspect, a solution containing the hyperpolarized molecule is introduced into any magnetic field to which it is exposed in a single vessel or in multiple vessels. In some aspects, when multiple vessels are used, the solution can be transferred between individual vessels at a flow rate of less than about 5 standard liters per minute (slm), or less than about 4, 3, 2, or 1 slm, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0024] In one aspect, the solution can be transferred into the processing magnetic field, signal detection magnetic field, or both at a rate of from about 0.5 m/s to about 100 m/s, from about 1 m/s to about 50 m/s, from about 1 m/s to about 5 m/s, from about 5 m/s to about 7 ms, or less than about 0.5 m/s.

[0025] In another aspect, the solution can be transferred into the processing and/or signal detection magnetic fields at a flow rate of from about 0.2 to about 10 slm, or at a flow rate of less than about 0.2, 0.2, 0.5, 1 , 5, or 10 slm, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values..

[0026] In any of these aspects, prior to performing the method, the hyperpolarized molecule can be produced using signal amplification by reversible exchange (SABRE), hydrogenation, sidearm hydrogenation, or another method. Exemplary methods for producing hyperpolarized molecules are described in WO2021207297A1. In another aspect, SABRE can be performed at from about -30 °C to about 100 °C, or at about -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, or about 100 °C, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In another aspect, SABRE can be performed in a magnetic field of from about 0 pT to about 100 mT, or at about 0, 5, 25, 50, 100, 200, 200, 300, 400, 500, 600, 700, 800, or 900 pT, or about 1 , 5, 25, 50, or 100 mT, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0027] Also disclosed are hyperpolarized molecules prepared by the disclosed methods, and biocompatible contrast agents including the hyperpolarized molecules.

[0028] Further disclosed herein is a method for diagnosing a disease or monitoring progress of a treatment of a disease in a subject, the method including at least the steps of: administering a disclosed hyperpolarized molecule or contrast agent to the subject; and performing imaging on the subject, wherein performing imaging enables visualization of the hyperpolarized molecule or contrast agent in the subject.

[0029] In an aspect, the subject can be a mammal such as, for example, a human, mouse, rat, pig, hamster, guinea pig, sheep, dog, cat, or horse. In one aspect, the hyperpolarized molecule or contrast agent can be administered to the subject in a single injection, or can be administered to the subject continuously for a period of from about 30 seconds to about 1 hour, or for 30 seconds, 1 , 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55 minutes, or about 1 hour, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0030] In a further aspect, the disease can be cancer, cardiovascular disease, or a metabolic disorder. In one aspect, the cancer can be prostate cancer, breast cancer, or brain cancer, or the metabolic disorder can be diabetes, pyruvate dehydrogenase complex deficiency, or pyruvate carboxylase deficiency. In any of these aspects, the imaging can be MRI, which can be carried out using a cryogen-cooled superconducting magnet or a cryogen-free magnet.

[0031] Many modifications and other embodiments disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

[0032] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0033] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0034] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification. [0035] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0036] While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class.

[0037] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0038] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.

Definitions

[0039] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by,” “comprising,” “comprises,” “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of” and “consisting of.” Similarly, the term “consisting essentially of” is intended to include examples encompassed by the term “consisting of. [0040] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a catalyst,” “a non-polar organic solvent,” or “a buffer,” include, but are not limited to, mixtures or combinations of two or more such catalysts, non-polar organic solvents, or buffers, and the like.

[0041] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0042] When a range is expressed, a further aspect includes from the one particular value and/or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “x to y” includes the range from ‘x’ to ‘y’ as well as the range greater than ‘x’ and less than ‘y.’ The range can also be expressed as an upper limit, e.g. 'about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x,’ ‘about y’, and ‘about z’ as well as the ranges of ‘less than x’, less than y’, and ‘less than z’. Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x,’ ‘about y,’ and ‘about z’ as well as the ranges of ‘greater than x,’ greater than y,’ and ‘greater than z.’ In addition, the phrase “about x’ to ‘y’”, where x’ and ‘y’ are numerical values, includes “about ‘x’ to about ‘y’”.

[0043] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or subranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1 % to 5%” should be interpreted to include not only the explicitly recited values of about 0.1 % to about 5%, but also include individual values (e.g., about 1%, about 2%, about 3%, and about 4%) and the sub-ranges (e.g., about 0.5% to about 1.1%; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0044] As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that “about” and “at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0045] As used herein, the term “effective amount” refers to an amount that is sufficient to achieve the desired modification of a physical property of the composition or material. For example, an “effective amount” of a polarization transfer catalyst refers to an amount that is sufficient to achieve the desired improvement in the property modulated by the formulation component, e.g. achieving the desired level of hyperpolarization. The specific level in terms of wt% in a composition required as an effective amount will depend upon a variety of factors including the amount and type of catalyst, amount and type of target molecule or substrate, amount and type of solvent, and presence and identity of any co-ligands.

[0046] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0047] Unless otherwise specified, temperatures referred to herein are based on atmospheric pressure (i.e. one atmosphere).

[0048] “Thermal polarization” as used herein refers to the fraction of nuclear spins that align with a magnetic field under normal conditions. This is typically a small number and can be measured in units of parts per million (ppm), even in a strong magnetic field. [0049] By contrast, “hyperpolarization” refers to nuclear spin polarization far beyond thermal equilibrium conditions. In one aspect, hyperpolarization aligns almost all spins with the magnetic field, achieving signal enhancements of up to 10,000,000-fold when compared to thermal polarization.

[0050] “Orthohydrogen” (o-H₂) is an isomeric form of molecular hydrogen. In o-H₂, the spins of both nuclei are symmetrically aligned. In one aspect, at room temperature and thermal equilibrium, approximately 75% of an H₂ sample is in the orthohydrogen (triplet) state.

[0051] “Parahydrogen” (p-H₂) is a second isomeric form of molecular hydrogen. In p-H₂, the spins of both nuclei are anti-symmetrically aligned. In one aspect, at room temperature and thermal equilibrium, approximately 25% of an H₂ sample is in the parahydrogen (singlet) state. In a further aspect, use of parahydrogen exhibits hyperpolarized signals in NMR spectra. In one aspect, the reactor and process disclosed herein use parahydrogen to induce transfer spin in order to induce hyperpolarization in samples for NMR and MRI analysis. “Parahydrogen Induced Polarization” or “PHIP” is a hyperpolarization technique using p-H₂ as a source of spin transfer for inducing hyperpolarization. In one aspect, PHIP involves chemical reaction of p-H₂.

[0052] As used herein, a “cryogen-free magnet” can refer to a solid state magnet array or to a “dry” magnet that does not consume liquid helium or liquid nitrogen but rather uses compressed recycled helium, which can be liquefied, to cool the magnet.

[0053] “Signal amplification by reversible exchange” or “SABRE” is a technique that can increase the visibility of compounds for the purpose of NMR and MRI analysis, which in turn allows lower detection limits and shorter scan times in NMR, as well as higher contrast and higher resolution in MRI imaging. In one aspect, a metal-containing catalyst transfers spin from parahydrogen to a substrate, which can then be imaged or analyzed as appropriate.

[0054] As used herein, a “polarization transfer catalyst” is a metal containing catalyst that transiently binds both a substrate molecule and p-H₂, thereby allowing polarization to transfer from the p-H₂ to the substrate in a magnetic field. In some aspects, the metal in the polarization transfer catalyst is iridium. In another aspect, the iridium is typically coordinated with species containing aromatic rings and/or nitrogen heterocycles.

[0055] In some aspects, a “co-ligand” can be used in the disclosed methods. As used herein, “co-ligand” refers to a molecule capable of coordinating with the metal center in a polarization transfer catalyst. A co-ligand can, in some aspects, enhance polarization transfer efficiency to a target molecule, or can enhance binding efficiency of target molecules to the polarization transfer catalyst, or any combination thereof. Useful co-ligands disclosed herein include, but are not limited to, DMSO, water, and combinations thereof.

[0056] As used herein, “substrate” and “target molecule” refer to a molecule or chemical species to which polarization transfer is desired. Substrate and/or target molecules may be bound to a polarization transfer catalyst, may be free in solution, or a combination thereof.

[0057] As used herein, a “metabolite” is any substance formed by a metabolic process or necessary for a metabolic process. In this aspect, a metabolite can be a protein, peptide, nucleic acid, sugar, lipid, vitamin, or a subunit or component thereof (e.g. amino acid, nucleobase, nucleoside, nucleotide, monosaccharide, disaccharide, fatty acid, cofactor, or any combination thereof). Meanwhile, as used herein, “drug” refers to any substance that has a physiological effect when introduced to at least one tissue or organ system. In an aspect, both metabolites and drugs can include small molecules produced by animals, plants, bacteria, fungi, algae, and/or other organisms including, but not limited to, plant secondary metabolites (e.g. alkaloids, terpenoids, phenolic compounds, polyketides, non-ribosomal peptides), antibiotics, and the like. In a further aspect, drugs can additionally include synthetic and semi-synthetic compounds.

[0058] As used interchangeably herein, “subject,” “individual,” or “patient” can refer to a vertebrate organism, such as a mammal (e.g. human). "Subject" can also refer to a cell, a population of cells, a tissue, an organ, or an organism, preferably to human and constituents thereof.

[0059] Unless otherwise specified, pressures referred to herein are based on atmospheric pressure (i.e. one atmosphere).

[0060] All volumes, pressures, concentrations, magnetic fields, chemicals, and other details below are given as examples for the purpose of the technical description of this technology for a generic and descriptive sense only and not for purposes of limitation.

[0061] Now having described the aspects of the present disclosure, in general, the following Examples describe some additional aspects of the present disclosure. While aspects of the present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit aspects of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the present disclosure. ASPECTS

[0062] The present disclosure can be described in accordance with the following numbered aspects, which should not be confused with the claims.

[0063] Aspect 1. A method for conserving hyperpolarization in a hyperpolarized molecule undergoing at least one processing step, the method comprising conducting the at least one processing step in a processing magnetic field having a magnetic field strength higher than a magnetic field strength of Earth.

[0064] Aspect 2. The method of aspect 1, wherein the hyperpolarized molecule comprises a drug or a metabolite.

[0065] Aspect 3. The method of aspect 1 or 2, wherein the at least one processing step comprises depressurization, precipitation, filtration, redissolution, performing at least one chemical reaction, performing a phase transfer process, or any combination thereof.

[0066] Aspect 4. The method of any one of aspects 1-3, wherein following hyperpolarization but prior to performing the at least one processing step, the molecule is transferred into the processing magnetic field in an adiabatic manner, wherein the condition for adiabaticity is described by: y-Beff » d /dt wherein y is a gyromagnetic ratio of at least one hyperpolarized nucleus in the molecule; wherein B_eff is an effective magnetic field acting on the at least one hyperpolarized nucleus; and wherein d<|)/dT is a derivative of the phase of a hyperpolarized spin state of the at least one hyperpolarized nucleus with respect to time.

[0067] Aspect 5. The method of any one of aspects 1-4, wherein following the at least one processing step, the molecule is transferred into a signal detection magnetic field in an adiabatic manner, wherein the condition for adiabaticity is described by: y-B_eff » d<|)/dt wherein y is a gyromagnetic ratio of at least one hyperpolarized nucleus in the molecule; wherein B_eff is an effective magnetic field acting on the at least one hyperpolarized nucleus; and wherein d<|)/dT is a derivative of the phase of a hyperpolarized spin state of the at least one hyperpolarized nucleus with respect to time.

[0068] Aspect 6. The method of aspect 4 or 5, wherein Betr comprises a main magnetic field Bo, an applied oscillating field B_o, a local field on a molecular scale, or any combination thereof.

[0069] Aspect 7. The method of aspect 6, wherein the local field on a molecular scale comprises a J coupling, a dipolar interaction, or any combination thereof.

[0070] Aspect 8. The method of any one of aspects 1-7, wherein the processing magnetic field, the signal detection magnetic field, or both have an axial or crosswise direction.

[0071] Aspect 9. The method of any one of aspects 1-8, wherein the processing magnetic field, the signal detection magnetic field, or both have a strength of from about 100 T to about 3 T.

[0072] Aspect 10. The method of any one of aspects 1-9, wherein the processing magnetic field, the signal detection magnetic field, or both are generated by an electromagnet, a Halbach array, another permanent magnet system, or any combination thereof.

[0073] Aspect 11. The method of any one of aspects 1-10, wherein the hyperpolarized molecule is introduced into the processing magnetic field, the signal detection magnetic field, or both using a second magnetic field.

[0074] Aspect 12. The method of aspect 11 , wherein the second magnetic field is a pulsed magnetic field or a static magnetic field.

[0075] Aspect 13. The method of any one of aspects 1-12, wherein a solution comprising the hyperpolarized molecule is introduced into the processing magnetic field, the signal detection magnetic field, or both in a single vessel or in multiple vessels.

[0076] Aspect 14. The method of aspect 13, wherein the solution is transferred between vessels at a flow rate of less than about 5 standard liters per minute (slm).

[0077] Aspect 15. The method of aspect 13 or 14, wherein the solution is transferred at a speed of from about 0.5 m/s to about 100 m/s into the processing magnetic field, the signal detection magnetic field, or both.

[0078] Aspect 16. The method of any one of aspects 13-15, wherein the solution is transferred into the processing magnetic field, the signal detection magnetic field, or both using a flow rate of from about 0.2 slm to about 10 slm inner diameter tubing. [0079] Aspect 17. The method of any one of aspects 4-16, wherein the at least one hyperpolarized nucleus comprises ¹H, ¹⁵N, ¹³C, or any combination thereof.

[0080] Aspect 18. The method of any one of aspects 1-17, wherein prior to performing the method, the hyperpolarized molecule is produced using signal amplification by reversible exchange (SABRE), hydrogenation, side-arm hydrogenation, another method, or a combination thereof.

[0081] Aspect 19. The method of aspect 18, wherein SABRE is performed at a temperature of from about -30 °C to about 100 °C.

[0082] Aspect 20. The method of aspect 18 or 19, wherein SABRE is performed in a magnetic field of from about 0 pT to about 100 mT.

[0083] Aspect 21 . A hyperpolarized molecule prepared by the method of any one aspects 1-

[0084] Aspect 22. A biocompatible contrast agent comprising the hyperpolarized molecule of aspect 21.

[0085] Aspect 23. A method for diagnosing a disease or monitoring progress of treatment of a disease in a subject, the method comprising:

(a) administering the hyperpolarized molecule of aspect 21 or the contrast agent of aspect 22 to the subject; and

(b) performing imaging on the subject, wherein performing imaging enables visualization of the hyperpolarized molecule or contrast agent in the subject.

[0086] Aspect 24. The method of aspect 23, wherein the subject is a mammal.

[0087] Aspect 25. The method of aspect 24 wherein the mammal is a human, mouse, rat, pig, hamster, guinea pig, sheep, dog, cat, or horse.

[0088] Aspect 26. The method of any one of aspects 23-25, wherein the hyperpolarized molecule or the contrast agent is administered to the subject in a single injection.

[0089] Aspect 27. The method of any one of aspects 23-25, wherein the hyperpolarized molecule or the contrast agent is administered to the subject continuously for a period of from about 30 seconds to about 1 hour. [0090] Aspect 28. The method of any one of aspects 23-27, wherein the disease comprises cancer, cardiovascular disease, or a metabolic disorder.

[0091] Aspect 29. The method of aspect 28, wherein the cancer comprises prostate cancer, breast cancer, or brain cancer.

[0092] Aspect 30. The method of aspect 28, wherein the metabolic disorder comprises diabetes, pyruvate dehydrogenase complex deficiency, or pyruvate carboxylase deficiency.

[0093] Aspect 31 . The method of any one of aspects 23-30, wherein the imaging is magnetic resonance imaging (MRI).

[0094] Aspect 32. The method of aspect 31 , wherein magnetic resonance imaging is carried out using a cryogen-cooled superconducting magnet.

[0095] Aspect 33. The method of aspect 31 , wherein magnetic resonance imaging is carried out using a cryogen-free magnet.

EXAMPLES

[0096] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.gr, amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.

Example 1 : General Method

[0097] Referring to FIG. 1, a solution is hyperpolarized with SABRE or other parahydrogen method in hyperpolarization vessel 110 at magnetic field S 100. The solution is adiabatically transferred to processing vessel 210 as disclosed herein using adiabatic transfer apparatus 150 at a rate equal to or less than 1 m/s or 1 slm in 1/8 inch (3.175 mm) inner diameter tubing or 0.25 slm in 1/16 (1.6 mm) inch inner diameter from magnetic field S 100 to magnetic field P 200. Magnetic field S 100 can be less than 100 pT, less than 50 pT, 0.3 pT, 0 pT or another value as disclosed herein. Magnetic field P 200 can be 3 T, 1 T, 500 mT, 400 mT, or 100 mT or another value as disclosed herein. Vessels 110 and 210 can be different vessels or the same vessel. [0098] The solution may undergo at least one processing step in vessel 210, or in another in-line or parallel component contained in magnetic field P 200. Processed hyperpolarized solution is adiabatically transferred to transfer vessel 310 using adiabatic transfer apparatus 250 as disclosed herein at equal to or less than a rate of 1 m/s or 1 slm in 1/8 inch (3.175 mm) inner diameter tubing or 0.25 slm in 1/16 (1.6 mm) inch inner diameter from magnetic field P 200 to magnetic field T 300. Magnetic field T 300 can be 1 T, 500 mT, 100 mT, or EMF, or another value as disclosed herein. Vessels 210 and 310 can be different vessels or the same vessel. In one aspect, 310 is a sterile syringe. In another aspect, 310 is a sterile vial. Processed hyperpolarized solution is adiabatically transferred from magnetic field T 300 to magnetic field D 400 using adiabatic transfer apparatus 350. This adiabatic transfer process can include the injection of the sample into an MRI phantom vessel, NMR sample, animal subject, human subject, or similar detection vessel or subject 410. Signal detection occurs within magnetic field D 400. Magnetic field D 400 can be 20 T, 10 T, 3 T, 1.5 T, 1 T, 500 mT, 300 mT, or 100 mT or another value as disclosed herein.

[0099] The process described above can contain any or all of these steps or sub-steps (e.g. processing, injection, etc.).

Example 2: Exemplary Protocol

[0100] A solution was hyperpolarized with SABRE using an iridium IMes catalyst concentration of 6 mM, DMSO concentration of 20 mM, and [1-¹³C]pyruvate concentration of 65 mM in 2 ml_ of methanol. The solution was pressurized to 100 psi and activated with parahydrogen bubbling for 10 minutes at 5 °C. The solution was then cooled to 0 °C for 1.5 minutes. After pre-cooling, the solution was transferred to an ambient temperature atmosphere (~20 °C) at a magnetic field of 0.3 pT inside of mu-metal shielding. The solution was then hyperpolarized by bubbling parahydrogen gas at 200 seem for 90 seconds. The solution was then adiabatically moved from the hyperpolarization vessel at 0.3 microtesla to a second vessel at 0.35 T field using backpressure and a mass-flow controller to achieve a controlled solution flow rate of 200 seem (0.2 slm). The solution was then depressurized (hydrogen pressure released) inside of the 0.35 T field and the solution was immediately withdrawn into a syringe at a rate of less than 0.5 slm. The hyperpolarized solution in the syringe was moved adiabatically into a magnetic field of -100 G (stray magnetic field of an MRI magnet) and injected into an animal subject through the tail vein. An MRI sequence was then used to capture the hyperpolarized signal in the animal subject.

Example 3: Retaining Adiabaticity During Sample Processing and Transport [0101] To remain in an adiabatic regime, when a sample is transported from an initial field Bi to a final field B_f, the rate of change of the angle 0 between the initial field Bi and the final B_f, fields (or more precisely initial Hamiltonian Hi and final Hamiltonian H_f) has to be much slower than the rate of precession of the spins about the magnetic field/Hamiltonian at any point in time during the transport. In FIG. 2, the change of the Hamiltonian is shown as going from an initial field Bi to a second, final, and as depicted, perpendicular guiding field Bf. The Laromor precession frequncy around the field is indicated by a cone around the field containing both componets of Bi and B_f during the transfer.

[0102] Making use of the fact that the angle 0 between Bi and B_f is given as 0(t) = arctan(B_f / Bi), d0/dt can be evaluated and the frequency of precession can be compared with the rate of change of the angle 0 as a function of transfer time as plotted in FIG. 3. The rate of change of the angle 0 is largest when the two fields Bi and B_f are comparable in size. In the favorable/adiabatic case, as plotted, the d0/dt has to remain significantly smaller than the nutation frequency co.

[0103] Any system has to be designed in such a way that the rate of change of the angle 0, has to be much smaller than the local frequency co experienced at any given position during the transport (i.e., d0/dt«co has to be fulfilled).

Example 4: SABRE-Hyperpolarized [1-¹³C]pyruvate Metabolism Detected In Vivo

Preclinical Scanner (4.7 T) In Vivo Experiments

[0104] 1-¹³C Pyruvate was hyperpolarized using a bubbling system and a Polarization Transfer Field (PTF) of 0.3 pT, then depressurized in a 1 T Halbach array. The 500 pL sample containing 6 mM Iridium-lmes catalyst, 24 mM DMSO, and 65 mM 1-¹³C pyruvate, was ejected into a prefilled 1.5 mL saline solution diluting the sample 3:1. These concentrations correspond to a dosage of xx mg/kg of pyruvate injected into -250 g Wistar rats. The dosage of pyruvate injected is much smaller than other hyperpolarization motifs in MRI studies. Spectroscopic data was obtained using a 20° pulse with a repetition time (TR) of 2 seconds.

In Vivo Spectroscopy

[0105] The first demonstration of employing SABRE to hyperpolarize 1-¹³C pyruvate for dynamic studies and metabolic conversion monitoring in vivo. Utilizing a 4.7 T MRI, spectroscopic in vivo data highlighting 1-¹³C pyruvate and its downstream metabolic turnovers was obtained. The liver and kidney were studied to observe different in-vivo chemical environments that are commonly researched due to differing metabolic turnovers. This work used surface coils on the target areas for precise locational measurements. The data was summed across all scans (FIGs. 4A and 4D) showing hyperpolarized pyruvate, along with its downstream metabolic derivatives lactate, and alanine as well as other byproducts of pyruvate hydrate and bicarbonate. These byproducts all retain the hyperpolarized labeled ¹³C allowing detection in the scans even though the relative amount of each is small. The dynamic acquisition allows us to monitor the decay of hyperpolarized signal across tens of seconds (FIGs. 4C and 4F). Lactate and alanine show a small buildup after injection once the pyruvate has time to metabolically convert. It is worth noting that the liver of the rat produced much more lactate and alanine compared to the kidney, due to the liver having a higher metabolic turnover rate for pyruvate.

In Vivo Spectroscopic Imaging

[0106] In addition to acquisition of the spectroscopic data, Chemical Shift Imaging (CSI) was implemented, elucidating locational information of the hyperpolarized ¹³C-pyruvate within the kidney (renal vein) and liver (hepatic vein) (FIGs. 5A and 5D). The individual spectra were integrated and turned into a heat map over the center anatomical slice of the imaged region (FIGs. 5B and 5E). The heat map was then linearly extrapolated to assist with visualization (FIGs. 5C and 5F). The pulse applied for these images only excited the ¹³C-pyruvate peak to ensure visibility. To assess the metabolic derivates a pulse program would need to be optimized that hit all of the different frequencies needed. The heat map allows one to visualize the location of pyruvate buildup within the organ. The CSI data will be critical in future studies utilizing a diseased model, where the production of lactate is greatly increased in the presence of a tumor via the Warburg effect. With the increase of lactate production one can map out cancerous cells in vivo through the use of SABRE and a CSI pulse.

Cryogen-Free Scanner (1.5 T) In Vivo Experiments

[0107] 1-¹³C pyruvate was hyperpolarized using a bubbling system and a polarization transfer field (PTF) of 0.3 pT, then depressurized in a 1 T Halbach array. The 500 pL sample containing 6 mM Iridium-lmes catalyst, 24 mM DMSO, and 65 mM 1-¹³C pyruvate, was ejected into a prefilled 1 mL saline solution diluting the sample 2:1. Spectroscopic data was obtained using a 20° pulse with a repetition time (TR) of 2 seconds (FIG. 6B).

In Vivo Spectroscopy [0108] Experiments were also conducted using a cryogen free variable field MRI. The use of a cryogen free MRI negates the necessity for large amounts of helium, reducing operation cost and maintenance. The variable fields of this MRI (0.5 - 3.5 T) make translation into clinical settings easier, as the common clinical field is 1 .5 - 3 T. Whole body scans used a volume coil in place of a surface coil. The magnetic field applied during these experiments was 1.5 T so direct correlation to clinical settings could be made. Summed spectra (FIG. 6A) show hyperpolarized pyruvate, along with its downstream metabolic derivatives lactate, and alanine as well as other byproducts of pyruvate hydrate and bicarbonate. The 1.5 T data is procured using a full body coil, so the signal achieved is an average across the whole body, resulting in lower metabolic derivative signal in comparison to 1-¹³C pyruvate signal. The shims of the 1.5 T device are worse as can be seen in FIG. 6A in comparison to FIGs. 4A and 4C, giving rise to lower signal and broader splitting. The experiments shown in FIGs. 6A-6C indicate the successful combination of low-cost hyperpolarization with low-cost MRI to achieve high-sensitivity in vivo molecular imaging, pushing forward this technology towards clinical adaptation.

Discussion

[0109] The first SABRE hyperpolarized in vivo studies were performed here using 1-¹³C pyruvate as the target substrate. 1-¹³C pyruvate was chosen due to its metabolic relevance in many disease pathways. In vivo studies were performed on two different instruments, a 4.7 T magnet and a 1.5 T magnet. The 4.7 T magnet benefits from a higher field strength, but the 1.5 T magnet is closer in field strength to clinical settings (1.5 - 3 T), while also being cryogen free. Both systems show large amounts of polarization on 1-¹³C pyruvate.

Sample Preparation

[0110] Under inert gas conditions, [1-¹³C]pyruvate, Ir(IMes) (IMes= 1 ,3 bis(2,4,6- trimethylphenyl)imidazole-2-ylidene) catalyst, and DMSO were mixed giving absolute concentrations of 65 mM [1 ,2-¹³C2]pyruvate, 24 mM DMSO, and 6 mM Ir-IMes in CD3OD. Ir-IMes catalyst was synthesized using a literature method. CD₃OD was used dry from the supplier (Cambridge Isotopes) and degassed using 5 freeze-pump-thaw cycles. All other chemicals were purchased from Millipore Sigma.

[0111] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the abovedescribed embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

CLAIMS What is claimed is:

1. A method for conserving hyperpolarization in a hyperpolarized molecule undergoing at least one processing step, the method comprising conducting the at least one processing step in a processing magnetic field having a magnetic field strength higher than a magnetic field strength of Earth.

2. The method of claim 1 , wherein the hyperpolarized molecule comprises a drug or a metabolite.

3. The method of claim 1 , wherein the at least one processing step comprises depressurization, precipitation, filtration, redissolution, performing at least one chemical reaction, performing a phase transfer process, or any combination thereof.

4. The method of claim 1 , wherein following hyperpolarization but prior to performing the at least one processing step, the molecule is transferred into the processing magnetic field in an adiabatic manner, wherein the condition for adiabaticity is described by: y-Beff » dc|)/dt wherein y is a gyromagnetic ratio of at least one hyperpolarized nucleus in the molecule; wherein Ben is an effective magnetic field acting on the at least one hyperpolarized nucleus; and wherein d<|)/dT is a derivative of the phase of a hyperpolarized spin state of the at least one hyperpolarized nucleus with respect to time.

5. The method of claim 1 , wherein following the at least one processing step, the molecule is transferred into a signal detection magnetic field in an adiabatic manner, wherein the condition for adiabaticity is described by:

Y-B_eff » dc|)/dt wherein y is a gyromagnetic ratio of at least one hyperpolarized nucleus in the molecule; wherein B_etf is an effective magnetic field acting on the at least one hyperpolarized nucleus; and wherein d<|)/dT is a derivative of the phase of a hyperpolarized spin state of the at least one hyperpolarized nucleus with respect to time.

6. The method of claim 4 or 5, wherein B_eff comprises a main magnetic field B_o, an applied oscillating field B_o, a local field on a molecular scale, or any combination thereof.

7. The method of claim 6, wherein the local field on a molecular scale comprises a J coupling, a dipolar interaction, or any combination thereof.

8. The method of claim 1 , wherein the processing magnetic field, the signal detection magnetic field, or both have an axial or crosswise direction.

9. The method of claim 1 , wherein the processing magnetic field, the signal detection magnetic field, or both have a strength of from about 100 pT to about 3 T.

10. The method of claim 1 , wherein the processing magnetic field, the signal detection magnetic field, or both are generated by an electromagnet, a Halbach array, another permanent magnet system, or any combination thereof.

11. The method of claim 1 , wherein the hyperpolarized molecule is introduced into the processing magnetic field, the signal detection magnetic field, or both using a second magnetic field.

12. The method of claim 11 , wherein the second magnetic field is a pulsed magnetic field or a static magnetic field.

13. The method of claim 1 , wherein a solution comprising the hyperpolarized molecule is introduced into the processing magnetic field, the signal detection magnetic field, or both in a single vessel or in multiple vessels.

14. The method of claim 13, wherein the solution is transferred between vessels at a flow rate of less than about 5 standard liters per minute (slm).

15. The method of claim 13, wherein the solution is transferred at a speed of from about 0.5 m/s to about 100 m/s into the processing magnetic field, the signal detection magnetic field, or both.

16. The method of claim 13, wherein the solution is transferred into the processing magnetic field, the signal detection magnetic field, or both using a flow rate of from about 0.2 slm to about 10 slm inner diameter tubing.

17. The method of claim 4 or 5, wherein the at least one hyperpolarized nucleus comprises ¹H, 1⁵N, ¹³C, or any combination thereof.

18. The method of claim 1 , wherein prior to performing the method, the hyperpolarized molecule is produced using signal amplification by reversible exchange (SABRE), hydrogenation, side-arm hydrogenation, another method, or a combination thereof.

19. The method of claim 18, wherein SABRE is performed at a temperature of from about -30 °C to about 100 °C.

20. The method of claim 18, wherein SABRE is performed in a magnetic field of from about 0 T to about 100 mT.

21. A hyperpolarized molecule prepared by the method of claim 1.

22. A biocompatible contrast agent comprising the hyperpolarized molecule of claim 21.

23. A method for diagnosing a disease or monitoring progress of treatment of a disease in a subject, the method comprising:

(a) administering the hyperpolarized molecule of claim 21 or the contrast agent of claim 22 to the subject; and

(b) performing imaging on the subject, wherein performing imaging enables visualization of the hyperpolarized molecule or contrast agent in the subject.

24. The method of claim 23, wherein the subject is a mammal.

25. The method of claim 24 wherein the mammal is a human, mouse, rat, pig, hamster, guinea pig, sheep, dog, cat, or horse.

26. The method of claim 23, wherein the hyperpolarized molecule or the contrast agent is administered to the subject in a single injection.

27. The method of claim 23, wherein the hyperpolarized molecule or the contrast agent is administered to the subject continuously for a period of from about 30 seconds to about 1 hour.

28. The method of claim 23, wherein the disease comprises cancer, cardiovascular disease, or a metabolic disorder.

29. The method of claim 28, wherein the cancer comprises prostate cancer, breast cancer, or brain cancer.

30. The method of claim 28, wherein the metabolic disorder comprises diabetes, pyruvate dehydrogenase complex deficiency, or pyruvate carboxylase deficiency.

31. The method of claim 23, wherein the imaging is magnetic resonance imaging (MRI).

32. The method of claim 31 , wherein magnetic resonance imaging is carried out using a cryogen- cooled superconducting magnet.

33. The method of claim 31 , wherein magnetic resonance imaging is carried out using a cryogen- free magnet.