Systems and methods for producing hyperpolarized materials

Abstract

Systems and methods for generating hyperpolarized molecules with high molar polarization are disclosed. The systems and methods generally mitigate or suppress strong demagnetizing fields that would otherwise be generated by polarized high concentration molecules. Since such a demagnetizing field may interfere with polarization transfer, mitigation of such a field increases molar polarization. The systems and methods generally use novel pulse sequences that counteract the effects of the demagnetizing field.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 375,390, filed on September 13, 2022, titled "SYSTEMS AND METHODS FOR GENERATION OF HYPERPOLARIZED MATERIALS" and U.S. Provisional Patent Application No. 63 / 460,629, filed on April 20, 2023, titled "SYSTEMS AND METHODS FOR GENERATION OF HYPERPOLARIZED MATERIALS", each of which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The disclosed embodiments generally relate to the generation of hyperpolarized materials for nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), or similar applications. Background Art

[0004] Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are techniques with important applications in chemistry, biology, and medical imaging. Despite these successes, it is recognized that magnetic resonance applications can often be limited due to the small nuclear polarization of analytes at thermal equilibrium (typically on the order of 10 -5 levels). Compared to other analytical techniques such as mass spectrometry, this small nuclear polarization can result in limited sensitivity.

[0005] Increasing the nuclear spin polarization beyond its thermal equilibrium value can significantly improve magnetic resonance sensitivity. Known techniques can be used to increase nuclear spin polarization, such as dynamic nuclear polarization (DNP), parahydrogen - induced polarization (PHIP), PHIP - sidearm hydrogenation (PHIP - SAH), PHIP via proton - exchange relay (PHIP - X), and PHIP nuclear Overhauser effect systems (PHIPNOESYS). Using such techniques, the nuclear spin polarization of a material can be increased by a factor of typically more than 100, and in some cases by more than 10,000 or more. The enhanced nuclear spin polarization can lead to a proportional increase in the NMR / MRI signal.

[0006] These techniques can achieve high polarization at moderate concentrations, making them an attractive approach for various applications. For example, polarized molecules prepared via PHIP or PHIP-SAH can be directly used in NMR or MRI experiments. Alternatively, the polarized molecules can serve as a source for transferring polarization to other molecules via procedures such as PHIPNOESYS and PHIP-X. However, when the polarized molecules are present at high concentrations, the strong demagnetizing field originating from the dipolar field associated with the magnetization of the polarized molecules in the sample interferes with the polarization transfer, thereby limiting the achievable product of polarization and concentration (i.e., molar polarization). Thus, to date, PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X are limited in terms of the achievable molar polarization. SUMMARY OF THE INVENTION

[0007] According to the present disclosure, a solution containing hyperpolarized molecules dissolved therein can be obtained. The hyperpolarized molecules can include at least one nucleus having a molar polarization of at least 50 millimoles (mM). Prior to obtaining the solution, a nuclear spin hyperpolarization scheme can be performed on the hyperpolarized molecules, thereby imparting the molar polarization to the at least one nucleus. The nuclear spin hyperpolarization procedure can include: obtaining a solution containing a derivative of the hyperpolarized molecules, the derivative including at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1-C═C-R2 or R1-C≡C-R2, where R1 and R2 include side chains; hydrogenating the double bond or the triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecules, the parahydrogenated derivative having the form R1-CH * -CH * -R2 or R1-CH * ═CH * -R2, where H * represents a hydrogen atom derived from parahydrogen added across the double bond or the triple bond; and applying a polarization transfer waveform to transfer nuclear spin order from at least one of the hydrogen atoms derived from parahydrogen to the at least one nucleus, thereby imparting nuclear spin hyperpolarization to the at least one nucleus. The polarization transfer waveform can be configured to suppress the dipolar field associated with the magnetization generated during the buildup of the nuclear spin hyperpolarization. The polarization transfer waveform can include a dipolar decoupling sequence. The polarization transfer waveform can further include a cascaded drive field based on a parameter scan. The parameter scan can further include a transverse magnetic field (B 1 ) scan. For example, the polarization transfer waveform can include a B 1Scanning. The polarization transfer waveform may include a pulse sequence selected from the group consisting of polarization MREV-8, polarization BLEW-12, and polarization BR-24. The hyperpolarized molecules can be used for PHIP, PHIP-SAH, PHIPNOESYS, or PHIP-X experiments. The polarization transfer waveform may allow molar polarization that otherwise cannot be obtained due to magnetization accumulation during the polarization procedure.

[0008] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not restrictive of the disclosed embodiments as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings, which are a part of this specification, illustrate several embodiments and, together with the description, serve to explain the principles and features of the disclosed embodiments. In the drawings:

[0010] Figure 1 An exemplary method for generating high molar polarization in hyperpolarized molecules via a PHIP nuclear spin hyperpolarization scheme according to the disclosed embodiments is depicted.

[0011] Figure 2 An exemplary method 200 for generating high molar polarization in hyperpolarized molecules via a PHIP-SAH nuclear spin hyperpolarization scheme according to the disclosed embodiments is depicted.

[0012] Figure 3 Shows exemplary numerical simulations of the molar polarization of polarization MREV-8, polarization BLEW-12, polarization BR-24, and transverse magnetic field scans relative to concentration at the Lee-Goldburg frame pulse sequence for (1- 13 C,d 6 )-dimethyl maleate according to the disclosed embodiments.

[0013] Figure 4 Shows exemplary numerical simulations of the molar polarization of polarization MREV-8, polarization BLEW-12, polarization BR-24, and transverse magnetic field scans relative to concentration at the Lee-Goldburg frame pulse sequence for (1- 13 C)-fumaric acid according to the disclosed embodiments.

[0014] Figure 5 Shows exemplary numerical simulations of the molar polarization of polarization MREV-8, polarization BLEW-12, polarization BR-24, and transverse magnetic field scans relative to concentration at the Lee-Goldburg frame pulse sequence for (1,2-d 2 )-ethyl acetate according to the disclosed embodiments.

[0015] Figure 6 Shows the exemplary hyperpolarization (1- 13 C,d 6 )-dimethyl maleate as a function of concentration. 1 H molar polarization.

[0016] Figure 7 Shows the exemplary hyperpolarization (1- 13 C,d 6 )-dimethyl maleate as a function of the effective angle of Lee-Goldburg decoupling. 1 H spin polarization.

[0017] Figure 8 Shows the exemplary hyperpolarization of 1- 13 C-d 6 -dimethyl maleate acquired at a 9.41 T magnetic field after polarization transfer using a polarized MREV-8 sequence. 1 H spectrum. DETAILED DESCRIPTION

[0018] Exemplary embodiments will now be discussed in detail with reference to the accompanying drawings. In some cases, the same reference numerals will be used throughout the drawings and the following description to refer to the same or similar parts. Unless otherwise defined, technical and / or scientific terms have the meaning commonly understood by one of ordinary skill in the art. The disclosed embodiments are described in sufficient detail to enable one of ordinary skill in the art to practice the disclosed embodiments. It should be understood that other embodiments may be utilized and changes may be made without departing from the scope of the disclosed embodiments. Thus, the materials, methods, and examples are illustrative only and are not intended to be limiting necessarily.

[0019] NMR and MRI can be used in a variety of applications, including but not limited to determining the chemical structure in synthetic intermediates, determining the atomic-level structure and dynamics in proteins and nucleic acids, minimally invasive imaging of biological tissues or organisms, and even metabolic analysis of biological tissues or organisms. However, due to the combination of the tiny size of the nuclear magnetic resonance magnetic moment and the correspondingly small polarization at thermal equilibrium, NMR and MRI can have limited sensitivity. This limited sensitivity may impede the use of NMR and MRI in some applications and may make other applications of NMR and MRI impractically time-consuming or material-consuming.

[0020] The sensitivity of NMR and MRI can be enhanced by using higher magnetic fields and optimized detection systems. However, an alternative approach is to increase the NMR and MRI sensitivity by increasing the nuclear spin polarization to a level significantly greater than thermal equilibrium. Such hyperpolarization techniques can generally enhance the NMR and MRI sensitivity by a factor that is significantly greater than that obtained by increasing the magnetic field or using an optimized detection system.

[0021] A variety of techniques can be used to increase nuclear spin polarization, including dynamic nuclear polarization (DNP), parahydrogen-induced polarization (PHIP), PHIP-sidearm hydrolysis (PHIP-SAH), signal amplification by reversible exchange (SABRE), PHIP via proton exchange relay (PHIP-X), PHIP nuclear Overhauser effect system (PHIPNOESYS), spin exchange optical pumping (SEOP), optically initialized electron triplets (also known as photoexcited triplets, PETS), and other suitable methods. Among these techniques, parahydrogen-based methods (such as PHIP, PHIP-SAH, PHIP-X, and PHIPNOESYS) are particularly promising because they can be performed at high throughput using relatively low-cost equipment.

[0022] For example, recent work in NMR and MRI has demonstrated that the NMR and MRI signals associated with various bio-related contrast agents can be enhanced by many orders of magnitude using PHIP or PHIP-SAH. Such dramatic signal enhancements allow for spectroscopic analysis of bio-related contrast agents as they are metabolized by various tissues at different locations in the body. Analysis of the metabolic information determined by such spectroscopic imaging can allow for non-invasive determination of the health status of tissues in the body. For example, abnormal metabolism of bio-related contrast agents may signal a disease, such as cancer, at some locations in the body.

[0023] In PHIP and PHIP-SAH, a derivative (e.g., a precursor) of the molecule of interest is reacted with parahydrogen to form a parahydrogenated form of the derivative. The spin order is then transferred from the proton added via the parahydrogenation reaction to the relevant nuclei (such as carbon-13 nuclei) contained within the molecule of interest. In PHIP, the parahydrogenated form of the derivative is chemically identical to the molecule of interest and is distinguishable from the molecule of interest only by the spin order derived from the parahydrogenation reaction. In PHIP-SAH, the parahydrogenated form of the derivative is cleaved (e.g., hydrolyzed) to produce a hyperpolarized molecule of interest. In SABRE, the molecule of interest itself forms a coordination complex with a polarization transfer catalyst and parahydrogen. The spin order is then transferred from parahydrogen to the relevant nuclei within the molecule of interest via the coordination complex. The molecule of interest is then optionally purified and used in NMR or MRI procedures. PHIP-X and PHIPNOESYS utilize PHIP or PHIP-SAH to produce hyperpolarized materials (e.g., source compounds), and transfer the polarization from the source compound to the material used in NMR spectroscopy (e.g., target compound, target molecule, or molecule of interest). In PHIP-X, the transfer or polarization from the source compound to the target compound occurs via proton exchange from the source compound to the target compound. Subsequently, the polarization can be internally transferred within the target compound by the nuclear Overhauser effect (NOE) within the molecule. The polarization transfer from the source compound to the target compound in PHIPNOESYS occurs via an intermolecular NOE. PHIPNOESYS has been shown to increase the signal in NMR spectroscopy by nearly 2,000-fold, allowing NMR spectroscopy to be applied at concentrations significantly lower than those otherwise achievable.

[0024] The ultimate goal of hyperpolarization techniques such as PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X is to produce high concentrations of highly polarized molecules. However, when polarized molecules are present at high concentrations, the strong demagnetizing fields originating from the polarized molecules in the sample interfere with polarization transfer, thereby limiting the achievable product of polarization and concentration (i.e., molar polarization). Thus, to date, PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X have been limited in terms of achievable molar polarization. Accordingly, there is a need for systems and methods that counteract the effects of the large demagnetizing fields that arise when polarized molecules are present at high concentrations and that allow for the production of large molar polarizations.

[0025] As described herein, the challenges posed by the strong demagnetizing fields discussed above can be mitigated using novel pulse sequences that counteract the effects of the demagnetizing fields. The systems and methods described herein are capable of achieving effective polarization transfer even at high concentrations, without being limited by molar polarization. Such new pulse sequences open up exciting opportunities for the use of hyperpolarization techniques in a wide range of applications including MRI and drug discovery, and have potential implications for molecular imaging, materials science, and the like.

[0026] The disclosed embodiments produce hyperpolarized molecules dissolved in a solution. The hyperpolarized molecules typically contain at least one nucleus having a large molar polarization. The large molar polarization is generated by applying a polarization transfer waveform during the buildup of polarization on at least one nucleus. The polarization transfer waveform is typically configured to suppress the dipolar field associated with the magnetization generated during the buildup of polarization. For example, the polarization transfer waveform can include any one or more of the following: a dipolar decoupling sequence, a transverse magnetic field scan at, e.g., a Lee-Goldburg frame, a polarized MREV-8 pulse sequence, a polarized BLEW-12 pulse sequence, a polarized BR-24 pulse sequence, etc. After the polarization transfer waveform, at least one nucleus can be associated with a relatively high molar polarization. Then, in an NMR or MRI experiment, end users such as hospitals or clinics can use the hyperpolarized molecules.

[0027] Hyperpolarization and parahydrogen

[0028] As used in this disclosure, "polarization" refers to an imbalance in the orientation of electron or nuclear spins. In some embodiments, the polarization can be a normalized approximate difference of the number of spins in a first direction minus the number of spins in the opposite direction. As a non-limiting example, given 200,000 1 H nuclear spins, 2% polarization can correspond to 102,000 spins in a first direction and 98,000 spins in the opposite direction. In some embodiments, "hyperpolarization" can include polarization of a species (e.g., nucleons, electrons, etc.) that exceeds the typical polarization level of the species observed under thermal equilibrium in the presence of a particular magnetic field. As a non-limiting example, a sample of 1 H nuclear spins in a 1 Tesla (T) magnetic field at thermal equilibrium with a polarization exceeding 0.000341% can be hyperpolarized to have a 1 H nuclear spin polarization that is significantly higher (e.g., at least one or more orders of magnitude higher) than the 0.000341% thermal equilibrium polarization. As another non-limiting example, a sample of 13 C spins in a 3T magnetic field at thermal equilibrium with a polarization exceeding 0.000257% can be hyperpolarized. As another non-limiting example, a sample of 15 N spins in a 3T magnetic field at thermal equilibrium with a polarization exceeding 0.000103% can be hyperpolarized.

[0029] As used in this disclosure, "hyperpolarization" describes a condition where the absolute value of the difference between the spin state populations (e.g., nuclear spin states, proton spin states, etc.) in one state (e.g., spin-up) and the spin state populations in another state (e.g., spin-down) exceeds the absolute value of the corresponding difference under thermal equilibrium.

[0030] In accordance with the disclosed embodiments, parahydrogen can be used as a polarization source. As described herein, parahydrogen is a form of molecular hydrogen in which the two proton spins are in a singlet state. The disclosed embodiments are not limited to a particular method of generating parahydrogen. Parahydrogen can be formed in gaseous or liquid form. In some embodiments, parahydrogen in gaseous form is produced by flowing hydrogen gas at low temperature through a chamber having a catalyst (e.g., iron oxide or another suitable catalyst). The hydrogen gas can contain both parahydrogen and orthohydrogen. The low temperature can bring the hydrogen gas to thermodynamic equilibrium within the chamber, thereby increasing the parahydrogen population.

[0031] As used in this disclosure, the population difference between two spin states is the difference between the populations of the two spin states divided by the total population of the two spin states. The population difference can be expressed as a fractional population difference or a percentage population difference. In some embodiments, the fractional population difference is at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or more, at most about 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 or less, or within a range defined by any two of the foregoing values.

[0032] Hydrogen gas can exhibit a population difference between proton spin states that significantly exceeds the population difference between proton spin states at thermal equilibrium. Hydrogen gas containing a high concentration of parahydrogen can have a large population difference between the singlet spin state and any triplet spin state. In the case of Iz1Iz2, for example, there is a large population difference between the spin states |↑>|↓> and the spin state |↑>|↑>. The population difference of the proton spin states can be at least about 0.1 (e.g., a 10% difference in spin states or 55% of the parahydrogen molecules in the sample are in the singlet state and 45% are in the triplet state), 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or more, at most about 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 or less, or within a range defined by any two of the foregoing values.

[0033] As used in this disclosure, "molar polarization" refers to the product of the polarization and concentration of a particular nucleus. As used in this disclosure, molar polarization is typically cited in concentration units (such as millimolar (mM) units) and is obtained by multiplying the concentration of a particular nucleus by its polarization expressed as a fractional value. For example, a molecule may be present in a solution at a concentration of 100 mM. The molecule may contain a single carbon-13 nucleus with a nuclear spin polarization of 40% (i.e., the polarization is 0.4). In this disclosure, such a molecule will have a carbon-13 molar polarization of 100 mM multiplied by 0.4 = 40 mM. Similarly, a molecule present in a solution at a concentration of 100 mM will have a proton polarization of 60 mM, the molecule containing two identical protons each with a nuclear spin polarization of 30%. Thus, different molar polarizations can be obtained for different nuclei within a molecule.

[0034] Theoretical background

[0035] In conventional hyperpolarization experiments utilizing dynamic nuclear polarization (DNP), the concentration of the target nucleus is typically low enough such that the magnetic field generated by the target nucleus during polarization buildup is negligible. This is also the case for medium-concentration PHIP, PHIP-SAH, PHIP-X, and PHIPNOESYS experiments. However, numerical studies of high-concentration PHIP have shown that when the molar polarization exceeds a certain value, this is no longer the case. At this point, the magnetic field generated by the target nucleus can become strong enough to exceed the oscillation frequency associated with the splitting of the hydrogen pseudospin. This can lead to the nonlinear equations including the reaction of the nucleus as an average-field contribution becoming chaotic.

[0036] Although it may seem possible to eliminate the presence of the demagnetizing field in a spherical reaction chamber, this can only be achieved by a completely uniform spatial distribution of the nucleus and its polarization (i.e., polarization density). In reality, even in a spherical chamber, these quantities may fluctuate randomly, making it difficult to completely avoid the demagnetizing field. In a chaotic state, such random fluctuations can amplify very rapidly (e.g., growing exponentially in time), further exacerbating the problem. Additionally, in para-hydrogen-based polarization procedures, the para-hydrogenation reaction is subject to random fluctuations, which also makes it difficult to avoid the demagnetizing field solely through geometric considerations. Therefore, it is necessary to develop methods to suppress the influence of the demagnetizing field on the polarization dynamics.

[0037] The systems and methods described herein solve this problem by combining dipolar decoupling schemes (including but not limited to Lee - Goldburg decoupling, MREV - 8 decoupling, BLEW - 12 decoupling, or BR - 24 decoupling) and cascaded drive fields to develop novel polarization schemes (referred to herein as transverse magnetic field scans at the Lee - Goldburg frame, polarized MREV - 8, polarized BLEW - 12, or polarized BR - 24, respectively) based on a parameter scan that is highly robust and not limited by the molecular concentration undergoing the hyperpolarization procedure.

[0038] Accepted system

[0039] To describe PHIP and hyperpolarization in high concentrations, a model similar to that introduced in the following is used: M.C. Korzeczek et al., “Towards a unified picture of polarization transfer – equivalence of DNP and PHIP,” arXiv:2303.07478 (2023) (hereinafter referred to as “Korzeczek2023”) and J. Eills et al., “Singlet order conversion and parahydrogen - induced hyperpolarization of 13 13C nuclei in near - equivalent spin systems,” J. Magn. Reson. 274, 163 - 172 (2017), each of which is incorporated herein by reference in its entirety for all purposes. This model is combined with a semi - classical mean - field description of the effects from intermolecular dipole - dipole coupling and dipolar fields (see, e.g., M.H. Levitt, “Demagnetization field effects in two - dimensional solution NMR,” Conc. Magn. Reson. 8, 77 - 103 (1996), which is incorporated herein by reference in its entirety for all purposes). For the derivation of the transfer sequence, a two - spin system in Korzeczek 2023 is considered.

[0040] The full dynamics are described by: i) the single - molecule Hamiltonian H 0 , ii) the magnetic field H BThe influence of, and iii) intermolecular coupling as described by the dipole field H dip The intermolecular coupling described by dip .

[0041]

[0042] The molecule is described by two (pseudo) spins S and I, where the former is driven by a driver (such as a radio frequency (RF) driver, a transverse magnetic field (B 1 ) driver, etc.). The spins are coupled by terms of the form The magnetic field is decomposed into and it is assumed that the non-constant field only affects the S spin (due to the frequency of the non-constant field). Additionally, it is assumed that the amplitudes of the subsequent contributions decrease, which ensures the validity of the rotating wave approximation (RWA) for a linearly polarized RF field. Among them it is found that the corresponding Hamiltonian function term is where H B0 corresponds to the constant B 0 field, and the sequence can use additional driving fields (B 1 (t), …). Here, γ S is the nuclear gyromagnetic ratio of the spin S. The contribution of a single molecule in a constant field is given by:

[0043]

[0044] Here, ω S =γ S B 0 and ω I =γ H B 0 are the Larmor frequencies of the S and I spins induced by the magnetic field of amplitude B 0 and pointing along the z-axis. As shown in Korzeczek 2023, this Hamiltonian function allows the analysis of the characteristics of different transfer schemes.

[0045] To describe the influence of dipole-dipole coupling between molecules in a high-concentration sample, a semi-classical mean-field description of the dipole field is used. However, it should be noted that all transfer schemes that suppress the contribution of the dipole field also suppress the contribution from the full quantum description of the dipole-dipole coupling.

[0046] For the mean-field description, it is first assumed that there is no coherence accumulation between different molecules, such that the dipole coupling between the S spins {S } at positions i across the sample results in a coupled Hamiltonian function:

[0047]

[0048] Here,​ Now, the mean-field assumption allows for the decoupling of the Hamiltonian function, but requires the magnetization across the samples to remain aligned throughout the experiment. In this case, the initial state of all molecules is and the pulses are designed to affect all samples equally. In a more general case, for example, the use of gradient pulses invalidates the mean-field description and gives rise to highly complex behavior. The mean-field Hamiltonian function is:

[0049]

[0050] Thus,[[]] it generally depends on the molecule i under consideration, and the dependence is parameterized by the matrix D i which depends on the particle positions. In practice, diffusion in liquid samples gives rise to a strong averaging of the interactions at positions that suppress the contributions from nearby molecules. However, the overall form of the terms remains the same.[[]]

[0051] Before entering the frame that co-rotates with the Larmor precession of S, the first field B 1 (t) is parameterized as where the detuning Δ 0 = ω s - ω 1 for the spin S.[[]]

[0052] Now one can enter the "(0)" frame that co-rotates with the (detuned) Larmor precession of S, ω S - Δ 0 to simplify the description. Using ω S >> Ω, ||D i ||, Δ 0 , one can discard the oscillatory terms and arrive at:

[0053]

[0054] Here,[[]] is a single scalar parameter that can vary for different molecules in the sample. In this work, the dynamics for a single fixed value of Δ dip (discarding the index i) will be considered, and the range within which controlled polarization transfer remains successful will be explored. As long as all molecules in the sample have values of Δ dip lying within this range, the combined dynamics will be adequately described by the mean-field description. In some cases (e.g., for certain choices of B 1 ), the combined dynamics can be adequately described by the mean-field description even for values of Δ dip outside this range. Complicating the given definition of , the true contributions from nearby molecules will be suppressed by motional diffusion because The spherical average value is zero. In this case, this removes the strong contributions from neighboring molecules and does not affect the validity of the representative description with a single parameter Δ dip of the representative description.

[0055] Effect of dipole field on non-adaptive sequences

[0056] For all typical polarization sequences, the rotation frame operator in the "(1)" frame is mainly oriented along a two-dimensional plane orthogonal to the direction of polarization accumulation. Here, it is assumed to be the z-axis without loss of generality. The reason for this shared property is that the contribution along the third (i.e., z) dimension does not contribute to the transfer, such that the maximum transfer rate implies the use of a two-dimensional plane. This property ensures that the vanishing and the effective interaction generated by the average Hamiltonian theory is equivalent to:

[0057]

[0058] Here, the dip contribution is removed from H . When the initial state corresponds to and the transfer A * produces z magnetization that is not affected by the dipolar field term. Using to describe the state with dimensionless magnetization m z (t). Note that the frame label "(1)" of has been omitted to emphasize that the symmetry of this term makes it independent of any rotation of only the spin S. In this effective interaction, now see that Δ dip m z (t) directly causes the resonance shift of the transition driven by A * . Therefore, polarization sequences that are not explicitly adjusted to work in the presence of a dipolar field cannot achieve the value Δ dip m z (t) >> A * .

[0059] Amplitude scan

[0060] For amplitude scans, assume an initial π / 2 pulse with phase -Y followed by a continuous wave pulse with amplitude Ω(t) and phase X. Later, this will be chosen as a linear amplitude scan. By During the pulse, there is:

[0061]

[0062]

[0063] Inserted into the complete Hamiltonian function and using a similar argument as before, this gives:

[0064]

[0065] Here, the fact that the S spin accumulates only the z magnetization is used to arrive at the second equality. By switching to a frame that co-rotates with the remaining dipolar field terms it is found that the corrected Rabi amplitude Ω′(t) = Ω(t) - Δ dip m z (t) is sufficient to formally recover the dipole-field-free behavior. By and one obtains:

[0066]

[0067] From this, it can be seen that reliable transfer via adiabatic amplitude scanning can be up to significantly higher than the demagnetizing fields of unadjusted sequences that are effective in demagnetizing fields. Next, consider how dynamical decoupling brings additional improvements.

[0068] Transfer during Lee-Goldburg decoupling

[0069] In this section, a sequence using two layers of driving fields and is introduced, where the first layer is a continuous-wave Lee-Goldburg decoupling (LG driver) that suppresses the dipolar-dipole interaction on a fast time scale without completely removing the interaction terms required for polarization transfer. The second driving field is chosen to correspond to the transfer scheme in the effective frame generated by the first driver.

[0070] To describe the LG driver, choose the constant and include the detuning as This gives:

[0071]

[0072] Here, μ = {x,y,z}, α x = 0, α y = 2π / 3 and α z = 4π / 3. This shows the rapid oscillation of the frequency . An important property of

[0073]

[0074] Note that for Eq. (19) to hold, the state ρ (1) (t) must be quasi-static within the integration period, which is assumed by Ω1 >>Ω 2 Satisfied. Select As The appropriate amplitude - modulated and phase - shifted “orthogonal” version of, we can obtain:

[0075]

[0076] Now define:

[0077]

[0078] Equations (22)-(24) form an S - and Orthogonal basis. Through all of these, we obtain the (1') - frame Hamiltonian function:

[0079]

[0080] This exactly corresponds to the (0) - frame Hamiltonian function with Δ dip = 0 and appropriately re - defined parameters and basis. Due to imperfect Will not completely cancel Δ dip , so select adiabatic amplitude scanning from the previous part as As the sequence of polarization transfer during the time period T. After the scan, the polarization accumulated on the spin S will be oriented along Which can be combined with a π / 2 pulse of the phase Y of To be re - oriented along Finally, the magnetization oriented along Can be returned to 1 By adiabatically reducing Ω to zero while During this time period, Rather than Ensuring that the state is not affected by the dipole field.

[0081] General dipole decoupling sequence as the basis of polarization transfer

[0082] Similar to how continuous - wave Lee - Goldburg decoupling acts in the previous part to suppress dipole coupling without suppressing (Allowing the addition of drivers to induce unhindered polarization transfer) basis, a similar method can be applied to any dipole - decoupling sequence. Such sequences can include frequency - switched Lee - Goldburg or full - pulse sequences such as MREV - 8, BLEW - 12, or BR - 24, etc. The defining characteristics of such dipole - decoupling sequences are:

[0083]

[0084] These properties are sufficient to ensure that in the approximate Hamiltonian theory approximation:

[0085]

[0086] This corresponds to the case where there is no dipole field. Achievable:

[0087]

[0088] Through this, it is possible to achieve:

[0089]

[0090] In principle, it will be necessary to use a The specific dipole decoupling sequence given by Typically, nonzero Item will be The frequency contribution in is generated, such as in the (0) frame, which is considered to be 1 / T 1 The repetition rate is an integer multiple of cause.

[0091] Without loss of generality, we now assume that we have access to the appropriate (0) frame Caused by The (1') frame pulse given And use To describe This yields the (1')-frame Hamiltonian:

[0092]

[0093] Surrounded by Initial (α) -β Pulse and final (α) β Pulse resonance to ω I Any polarization sequence of Polarization transfer.

[0094] Dipole decoupling polarization sequence

[0095] By recognizing the linearity of the dipole decoupling sequence Term added slowly (resonance to ω I ) carry changes its characteristics to a polarization sequence without strongly affecting the dipole decoupling characteristics. Sequences such as MREV-8, BLEW-12, and BR-24 can be modified to act as polarization sequences. The modified sequence can be redefined as follows.

[0096] Polarized MREV-8:

[0097]

[0098] Here, the total duration is T = 12τ, and the resonance condition is For the sequence returns to the original non-polarized MREV-8.

[0099] Polarized BLEW-12:

[0100]

[0101] Here, the total duration is T = 12τ, and the resonance condition is For the sequence returns to the original non-polarized BLEW-12.

[0102] Polarized BR-24:

[0103]

[0104] Here, the total duration is T = 24τ, and the resonance condition is For the sequence returns to the original non-polarized BR-24.

[0105] The same principle for constructing polarized MREV-8, BLEW-12, and BR-24 sequences can be used to modify any decoupling sequence (i.e., a sequence that does not decouple chemical shifts) having ...

[0106] Similarly, the principles described herein can be used to construct pulse sequences that allow for the generation of pulse sequences that enhance the molar polarization in hyperpolarized molecules prepared by alternative hyperpolarization techniques, such as DNP or dissolved DNP.

[0107] Method for generating high molar polarization

[0108] Figure 1 Exemplary method 100 for generating high molar polarization in hyperpolarized molecules via a PHIP nuclear spin hyperpolarization scheme in accordance with the disclosed embodiments is depicted. In some embodiments, the hyperpolarized molecule comprises at least one nucleus. In some embodiments, the at least one nucleus comprises at least one NMR-active nucleus, such as at least one proton, deuteron, carbon-13 nucleus, nitrogen-15 nucleus, oxygen-17 nucleus, fluorine-19 nucleus, phosphorus-31 nucleus, etc.

[0109] In some embodiments, method 100 imparts molar polarization to at least one nucleus. In some embodiments, the molar polarization is at least about 50 mM, 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM, 340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM, 440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM, 540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM, 640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM, 740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM, 840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM, 940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM, 1,000 mM or more.In some embodiments, the molar polarization is at least about 1,000 mM, 990 mM, 980 mM, 970 mM, 960 mM, 950 mM, 940 mM, 930 mM, 920 mM, 910 mM, 900 mM, 890 mM, 880 mM, 870 mM, 860 mM, 850 mM, 840 mM, 830 mM, 820 mM, 810 mM, 800 mM, 790 mM, 780 mM, 770 mM, 760 mM, 750 mM, 740 mM, 730 mM, 720 mM, 710 mM, 700 mM, 690 mM, 680 mM, 670 mM, 660 mM, 650 mM, 640 mM, 630 mM, 620 mM, 610 mM, 600 mM, 590 mM, 580 mM, 570 mM, 560 mM, 550 mM, 540 mM, 530 mM, 520 mM, 510 mM, 500 mM, 490 mM, 480 mM, 470 mM, 460 mM, 450 mM, 440 mM, 430 mM, 420 mM, 410 mM, 400 mM, 390 mM, 380 mM, 370 mM, 360 mM, 350 mM, 340 mM, 330 mM, 320 mM, 310 mM, 300 mM, 290 mM, 280 mM, 270 mM, 260 mM, 250 mM, 240 mM, 230 mM, 220 mM, 210 mM, 200 mM, 190 mM, 180 mM, 170 mM, 160 mM, 150 mM, 140 mM, 130 mM, 120 mM, 110 mM, 100 mM, 90 mM, 80 mM, 70 mM, 60 mM, 50 mM or less. In some embodiments, the molar polarization is within the range defined by any two of the foregoing values.

[0110] In the illustrated example, a solution is obtained at 110. In some embodiments, the solution comprises a derivative of a hyperpolarized molecule. In some embodiments, the derivative comprises at least one unsaturated carbon-carbon double bond or at least one unsaturated carbon-carbon triple bond. In some embodiments, the derivative has the form R1-C═C-R2 or R1-C≡C-R2. Here, R1 and R2 represent side chains, ═ represents a carbon-carbon double bond, and ≡ represents a carbon-carbon triple bond.

[0111] In some embodiments, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is configured to undergo a hydrogenation reaction with secondary hydrogen. Thus, at 120, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is hydrogenated with secondary hydrogen to form a secondary hydrogenated derivative of the hyperpolarized molecule. In some embodiments, the secondary hydrogenated derivative has the form R1-CH * -CH * -R2 or R1-CH * ═CH *-R2. Here, R1 and R2 represent side chains, - represents a carbon-carbon single bond, = represents a carbon-carbon double bond, and H * represents a hydrogen atom derived from secondary hydrogen added across a double or triple bond during a hydrogenation reaction.

[0112] In some embodiments, the hydrogenation reaction is carried out by mixing secondary hydrogen gas into a solution such that the secondary hydrogen gas is mixed with the derivative. In some embodiments, the first solution contains a hydrogenation catalyst. In some embodiments, the secondary hydrogen gas is mixed with the derivative in the presence of a hydrogenation catalyst. In some embodiments, in the presence of a hydrogenation catalyst, the mixture of the secondary hydrogen gas and the derivative molecules induces a secondary hydrogenation reaction between the secondary hydrogen gas and the derivative.

[0113] At 130, a polarization transfer waveform is applied. In some embodiments, the polarization transfer waveform transfers nuclear spin order from at least one of the hydrogen atoms derived from secondary hydrogen to at least one nucleus. In some embodiments, the polarization transfer waveform thus imparts nuclear spin hyperpolarization to at least one nucleus. In some embodiments, operation 130 is applied after operation 120. In some embodiments, the polarization transfer waveform is configured to suppress the dipolar field associated with the magnetization generated during the accumulation of nuclear spin hyperpolarization. In some embodiments, the polarization transfer waveform comprises any one or more of the following: a dipolar decoupling sequence, a transverse magnetic field, a (B 1 ) scan, and a pulse sequence selected from the group consisting of: polarized MREV-8, polarized BLEW-12, and polarized BR-24.

[0114] In some embodiments, operations 110, 120, and 130 produce hyperpolarized molecules. That is, in some embodiments, operations 110, 120, and 130 form a PHIP nuclear spin polarization scheme.

[0115] In some embodiments, the hyperpolarized molecules comprise any of the molecules of interest described herein. In some embodiments, the hyperpolarized molecules are used in NMR or MRI experiments.

[0116] In other embodiments, the nuclear spin polarization from the hyperpolarized molecules is transferred to any of the molecules of interest described herein, and the molecules of interest are used in NMR or MRI experiments. In some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecules to the molecules of interest by a PHIPNOESYS program or a PHIP-X program. That is, in some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecules to the molecules of interest by an intermolecular NOE between the hyperpolarized molecules and the molecules of interest or by proton exchange between the hyperpolarized molecules and the molecules of interest.

[0117] In some embodiments, method 100 further includes performing at least one purification protocol on the hyperpolarized molecule or the molecule of interest. Examples of purification protocols are described, for example, in WO2022018514 and WO2022269350, each of which is incorporated herein by reference in its entirety for all purposes.

[0118] Figure 2 Exemplary method 200 for generating high molar polarization in a hyperpolarized molecule via a PHIP-SAH nuclear spin hyperpolarization protocol according to the disclosed embodiments is depicted. In some embodiments, the hyperpolarized molecule includes at least one nucleus. In some embodiments, the at least one nucleus includes any NMR-active nucleus described herein with reference to Figure 1 any NMR-active nucleus described herein.

[0119] In some embodiments, method 200 imparts molar polarization to at least one nucleus. In some embodiments, the molar polarization is any molar polarization described herein with reference to Figure 1 any molar polarization described herein.

[0120] In the illustrated example, a solution is obtained at 210. In some embodiments, the solution includes a derivative of the hyperpolarized molecule. In some embodiments, the derivative includes at least one unsaturated carbon-carbon double bond or at least one unsaturated carbon-carbon triple bond. In some embodiments, the derivative has the form R1-C═C-R2 or R1-C≡C-R2. Here, R1 and R2 represent side chains, ═ represents a carbon-carbon double bond, and ≡ represents a carbon-carbon triple bond.

[0121] In some embodiments, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is configured to undergo a hydrogenation reaction with secondary hydrogen. Thus, at 220, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is hydrogenated with secondary hydrogen to form a secondary hydrogenated derivative of the hyperpolarized molecule. In some embodiments, the secondary hydrogenated derivative has the form R1-CH * -CH * -R2 or R1-CH * ═CH * -R2. Here, R1 and R2 represent side chains, - represents a carbon-carbon single bond, ═ represents a carbon-carbon double bond, and H * represents a hydrogen atom derived from secondary hydrogen added across the double bond or triple bond during the hydrogenation reaction.

[0122] In some embodiments, the hydrogenation reaction is performed by mixing secondary hydrogen gas into the solution such that the secondary hydrogen gas is mixed with the derivative. In some embodiments, the first solution contains a hydrogenation catalyst. In some embodiments, the secondary hydrogen gas is mixed with the derivative in the presence of the hydrogenation catalyst. In some embodiments, in the presence of the hydrogenation catalyst, the mixture of the secondary hydrogen gas and the derivative induces a secondary hydrogenation reaction between the secondary hydrogen gas and the derivative.

[0123] At 230, a polarization transfer waveform is applied. In some embodiments, the polarization transfer waveform transfers nuclear spin order from at least one para-hydrogen-derived hydrogen atom in para-hydrogen-derived hydrogen atoms to at least one nucleus. In some embodiments, the polarization transfer waveform thus confers nuclear spin hyperpolarization to at least one nucleus. In some embodiments, operation 230 is applied after operation 220. In some embodiments, the polarization transfer waveform is configured to suppress the dipolar field associated with the magnetization generated during the accumulation of nuclear spin hyperpolarization. In some embodiments, the polarization transfer waveform includes the polarization transfer waveform described herein with reference Figure 1 to the polarization transfer waveforms described.

[0124] At 240, the para-hydrogenated derivative is hydrolyzed. In some embodiments, hydrolyzing the para-hydrogenated derivative forms hyperpolarized molecules. In some embodiments, the para-hydrogenated derivative is mixed with a hydrolyzing agent such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). In some embodiments, the hydrolyzing agent hydrolyzes the para-hydrogenated derivative of the molecule of interest, thereby forming a hydrolyzed side arm and hyperpolarized molecules via PHIP-SAH interactions. Examples of PHIP-SAH interactions can be found, for example, in WO2022157534, WO2022018514, and WO2021198776, each of which is incorporated herein by reference in its entirety for all purposes.

[0125] In some embodiments, operations 210, 220, 230, and 240 produce hyperpolarized molecules. That is, in some embodiments, operations 210, 220, 230, and 240 form a PHIP-SAH nuclear spin polarization scheme.

[0126] In some embodiments, the hyperpolarized molecules include any molecule of interest described herein. In some embodiments, the hyperpolarized molecules are used in NMR or MRI experiments.

[0127] In other embodiments, the nuclear spin polarization from the hyperpolarized molecules is transferred to any molecule of interest described herein, and the molecule of interest is used in NMR or MRI experiments. In some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecules to the molecule of interest by a PHIPNOESYS procedure or a PHIP-X procedure. That is, in some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecules to the molecule of interest by an intermolecular NOE between the hyperpolarized molecules and the molecule of interest or by proton exchange between the hyperpolarized molecules and the molecule of interest.

[0128] In some embodiments, method 200 further includes performing at least one purification scheme on the hyperpolarized molecules or the molecule of interest. In some embodiments, the at least one purification scheme includes that described herein with respect to Figure 1Any of the described purification schemes.

[0129] Molecules of interest and biologically relevant contrast agents

[0130] The disclosed embodiments include systems and methods for generating and utilizing molecules of interest at clinically relevant polarizations, concentrations, volumes, or purities. In some embodiments, the methods are used to prepare NMR materials (also referred to herein as "molecules of interest"). In some embodiments, the NMR materials are suitable for use in NMR or MRI operations. In some embodiments, the NMR materials increase the NMR or MRI signal and signal-to-noise ratio (SNR). In some embodiments, the NMR materials are suitable for solution NMR spectroscopy. In some embodiments, the NMR materials are chemical compounds. In some embodiments, the NMR materials are metabolites (e.g., molecules with biological relevance such as amino acids, sugars, their derivatives, etc.), such as metabolites suitable for NMR metabolomics applications. In some embodiments, the NMR materials are suitable for in vitro probing of the metabolism of cell cultures or other biological tissues. In some embodiments, the NMR materials are used in NMR probes to study transient effects where high signal enhancements due to hyperpolarization are required, such as proton exchange between water and biomolecules. In some embodiments, the NMR materials are small molecules or metabolites suitable for injection into cells, tissues, or organisms for detection in MRI scans. In some embodiments, the NMR materials are introduced into a chamber for further analysis by NMR or MRI operations. In some embodiments, the NMR materials are enriched in one or more deuterium ( 2 H) or carbon-13 ( 13 C) atoms.

[0131] Consistent with the disclosed embodiments, the NMR material can include a bio-related contrast agent. In some embodiments, the bio-related contrast agent can be applicable to NMR or MRI operations. In some embodiments, the bio-related contrast agent can increase the NMR or MRI signal or the signal-to-noise ratio (SNR). In some embodiments, the bio-related contrast agent can be applicable to solution NMR spectroscopy. In some embodiments, the bio-related contrast agent can be a metabolite (e.g., a molecule with biological relevance such as an amino acid, sugar, its derivatives, etc.), such as a metabolite applicable to NMR metabolomics applications. In some embodiments, the bio-related contrast agent is used for perfusion imaging or contrast-enhanced imaging in MRI scans. In some embodiments, the bio-related contrast agent is suitable for in vitro detection of the metabolism of cell cultures or other biological tissues. In some embodiments, the bio-related contrast agent is used for in vitro detection of the metabolism of cell cultures or other biological tissues. In some embodiments, the bio-related contrast agent is used in an NMR probe to study transient effects, where high signal enhancement due to hyperpolarization is required, such as proton exchange between water and biomolecules. In some embodiments, the bio-related contrast agent is a small molecule or metabolite suitable for injection into cells, tissues, or organisms for detection in MRI scans. In some embodiments, the bio-related contrast agent is introduced into a chamber for further analysis by NMR or MRI operations. In some embodiments, the bio-related contrast agent is enriched with one or more 2 H or 13 C atoms.

[0132] In some embodiments, the bio-related contrast agent includes pyruvate, lactate, α-ketoglutarate, bicarbonate, fumarate, urea, dehydroascorbate, glutamate, glutamine, acetate, dihydroxyacetone, acetoacetate, glucose, ascorbate, ketoacetate, alanine, fructose, imidazole, nicotinamide, nitroimidazole, pyrazinamide, isoniazid, a conjugated acid of any one of the above natural and unnatural amino acids, its ester, or an 2 H, 13 C or nitrogen-15 ( 15 N)-enriched version. In some embodiments, the bio-related contrast agent includes pyruvate, lactate, α-ketoglutarate. In some embodiments, the bio-related contrast agent includes pyruvate. In some embodiments, the bio-related contrast agent includes lactate. In some embodiments, the bio-related contrast agent includes α-ketoglutarate (e.g., ethyl α-ketoglutarate).

[0133] In some embodiments, the bio-related contrast agent includes at least one non-hydrogen nuclear spin. In some embodiments, the non-hydrogen nucleus includes at least one spin-1 / 2 atom. In some embodiments, the non-hydrogen nuclear spin includes 13 C or 15N. In some embodiments, the bio-related contrast agent is at least partially isotopically labeled with non-hydrogen nuclear spins. In some embodiments, the bio-related contrast agent is at least partially enriched in non-hydrogen nuclear spins when compared to an analogue of the bio-related contrast agent that characterizes non-hydrogen nuclear spins at their natural abundance. In some embodiments, the bio-related contrast agent is enriched to characterize the non-hydrogen nuclear spins at an abundance of at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more, up to about 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or less, or within a range defined by any two of the foregoing values.

[0134] In some embodiments, the non-hydrogen nuclear spins replace NMR-inactive (i.e., spin-0) nuclei (e.g., 12 C or quadrupolar (i.e., spin > 1 / 2) nuclei) (e.g., nitrogen-14, 14 N) of an analogue of the bio-related contrast agent that characterizes non-hydrogen nuclear spins at their natural abundance. For example, an analogue of pyruvate that characterizes 13 C may contain about 98.9% 3 C and about 1.1% 12 C at any one of the C* in the structure H 13 C-C*(=O)-C*OOH. As a bio-related contrast agent, pyruvate may alternatively be enriched with 13 C isotopes such that one or both of the C* include 13 C at any of the abundances described herein. As used herein, *C and C* describe carbons that may be 12 C or 13 C carbon isotopes. Again, an analogue of urea that characterizes 15 N may include about 99.6% 2 N and about 0.4% 2 N at any one of the N* in the structure H 14 N*-C(=O)-*NH 15 . As a bio-related contrast agent, urea may alternatively be enriched in 15 N isotopes such that one or both of the N* contain15 N. As used herein, *N and N* describe nitrogen that can be 14 N or 15 nitrogen of N nitrogen isotopes.

[0135] Precipitation

[0136] In various embodiments, the hyperpolarized molecule or the molecule of interest can crystallize or precipitate out of the solutions described herein. The disclosed embodiments are not limited to any particular method of inducing such precipitation. For example, such precipitation can be induced by: changing the temperature or pH, applying electromagnetic stimulation (e.g., optical radiation such as ultraviolet radiation or optical radiation of another or multiple suitable wavelengths), mechanical stimulation (e.g., ultrasound, agitation, or another suitable mechanical stimulation), adding another solute or solvent to the solution, or another suitable method or any combination thereof. In some embodiments, after precipitation, the molecule of interest can be separated from the solution (e.g., using a filter or another suitable method). In some embodiments, the molecule of interest can then be combined or redissolved in another solution. This solution can have the properties desired for the intended NMR or MRI application (e.g., biocompatibility, concentration, volume, temperature, pH, polarity, or other relevant properties, or any combination thereof).

[0137] Use of molecules of interest and biologically relevant contrast agents

[0138] In some embodiments, at least a portion of the molecule of interest can be injected into a subject or patient for an MRI experiment. In various embodiments, at least a portion of the molecule of interest can be used for NMR spectroscopy. At least one NMR or MRI pulse sequence can be applied to the molecule of interest.

[0139] The foregoing description is presented for purposes of illustration. It is not exhaustive and is not limited to the precise forms or embodiments disclosed. Modifications and adaptations of the embodiments will be apparent by considering the specification and the practice of the disclosed embodiments. For example, the described embodiments include hardware, but systems and methods consistent with the present disclosure can be implemented with hardware and software. Additionally, although certain components have been described as being coupled to each other, such components can be integrated with each other or distributed in any suitable manner.

[0140] In addition, while illustrative embodiments have been described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., combinations of aspects of various embodiments), adaptations or alterations based on the present disclosure. Elements in the claims will be broadly interpreted based on the language employed in the claims and not limited to the examples described in the specification or during the implementation of the application, which examples are to be construed as non-exclusive. Further, the steps of the disclosed methods can be modified in any manner, including reordering steps or inserting or deleting steps.

[0141] The features and advantages of the present disclosure are apparent from the detailed description, and thus the appended claims are intended to cover all systems and methods falling within the true spirit and scope of the present disclosure. As used herein, the indefinite articles "a" and "an" mean "one or more." Similarly, unless the use of a plural term is clear in a given context, it does not necessarily denote a plural. Further, since various modifications and changes will readily occur to those of skill in the art by studying the present disclosure, it is not desired to limit the present disclosure to the exact construction and operation shown and described, and thus all suitable modifications and equivalents may be resorted to and fall within the scope of the present disclosure.

[0142] As used herein, unless otherwise specifically stated, the term "or" encompasses all possible combinations (both conjunctive and disjunctive), unless infeasible. For example, if it is stated that a component can include A or B, then unless otherwise specifically stated or infeasible, the component can include A alone, or B alone, or A and B. As a second example, if it is stated that a component can include A, B, or C, then unless otherwise specifically stated or infeasible, the component can include A alone, or B alone, or C alone, or A and B, or A and C, or B and C, or A and B and C.

[0143] Examples

[0144] Example 1: Numerical simulation of polarization transfer kinetics

[0145] The systems and methods herein are for digitally evaluating the polarization transfer kinetics of various molecules using various unadjusted and adjusted pulse sequences. The Hamiltonian function used corresponds to a two-spin system for describing homonuclear PHIP with the following correspondences. A pair of hydrogens with a J-coupling having an intensity ω I = J is driven by a pulse, and A ⊥ = J (1) -J (2) with heteronuclear 13The differential coupling of C spins provides terms that allow transitions between singlet and triplet states of hydrogen nuclei. In the numerical simulations, the homonuclear case was considered, where the drive affects hydrogen and the heteronuclear spins only act as a background inducing the necessary chemical shifts. A suitable driver cancels the Hamiltonian terms of the two individual spins and thus also decouples the combined states.

[0146] For the numerical simulations, parameters from three different molecules (carbon-13 labeled dimethyl-d-malate, carbon-13 labeled fumaric acid, and d-ethyl acetate) were used. For fumaric acid, the molecule without carbon-13 spin labeling was used. Thus, to induce the chemical shift, a magnetic field amplitude of 100 millitesla (mT) was used instead of 100 microtesla (μT) for the other two molecules to simulate fumaric acid. The numerical simulations explicitly simulated all 3 (2 for ethyl acetate) spins, rather than the representative Hamiltonian in the previous section. The J-coupling between hydrogens J, and (where applicable) the heteronuclear J-coupling between two hydrogens and carbon spins J (1) and J (2) In the case of, the relevant parameters for different molecules become (1- 13 C,d 6 )-dimethyl-d-malate: J = (2π)12.2 Hz, J (1) = (2π)13.1 Hz, J (2) = (2π)2.7 Hz; (1- 13 C)-fumaric acid: J = (2π)7.1 Hz, J (1) = (2π)3.2 Hz, J (2) = (2π)0.4 Hz; (1,2-d 2 )-ethyl acetate: J = (2π)15.9 Hz, A = 100 mT, chemical shift = 2.88 parts per million (ppm) ≈ (2π)12.3 Hz.

[0147] Example 2: (1- 13 C,d 6 ) - The polarization of dimethyl maleate by MREV-8, BLEW-12, BR-24 and at Numerical simulation of transverse magnetic field scan at Lee-Goldburg frame

[0148] Figure 3 Shows the molar polarization of (1- 13 C,d 6 )-dimethyl-d-malate relative to the polarization MREV-8 ( Figure 3 "MREV-8adj" in Figure 3 ), the polarization BLEW-12 ( Figure 3 "BLEW-12adj" in Figure 3Exemplary numerical simulations of the concentration of “LG + scan” in. Perform numerical simulations as described herein for Example 1. Also simulated SLIC and pure transverse magnetic field scans ( Figure 3 “scan” in) to enable a proper comparison between the pulse sequences described herein and prior pulse sequences. For ease of performing the simulations, the concentration is expressed in units of (2π) Hz. As discussed herein, the concentration can be converted to mM units by multiplying by a proportionality constant. Similarly, the molar polarization is expressed in units of (fractional) polarization multiplied by (2π) Hz and can be converted to molar polarization (in mM) by multiplying by a proportionality constant. As shown in Figure 3 , the pulse sequences described herein are significantly superior to SLIC and pure transverse magnetic field scan methods, where the transverse magnetic field scan at the Lee - Goldburg frame achieves the highest molar polarization.

[0149] Example 3: (1- 13 C)-Polarized MREV-8, polarized BLEW-12, polarized BR-24 of fumaric acid, and in Lee-Goldburg Numerical simulation of transverse magnetic field scan at the frame

[0150] Figure 4 Shows the molar polarization of (1 - 13 C) - fumaric acid relative to polarization MREV - 8 ( Figure 4 “MREV - 8adj” in), polarization BLEW - 12 ( Figure 4 “BLEW - 12adj” in), polarization BR - 24 ( Figure 4 “BR - 24adj” in) and the transverse magnetic field scan at the Lee - Goldburg frame pulse sequence ( Figure 4 “LG + scan” in). Perform numerical simulations as described herein for Example 1. Also simulated SLIC and pure transverse magnetic field scans ( Figure 4 “scan” in) to enable a proper comparison between the pulse sequences described herein and prior pulse sequences. For ease of performing the simulations, the concentration is expressed in units of (2π) Hz. As discussed herein, the concentration can be converted to mM units by multiplying by a proportionality constant. Similarly, the molar polarization is expressed in units of (fractional) polarization multiplied by (2π) Hz and can be converted to molar polarization (in mM) by multiplying by a proportionality constant. As shown in Figure 4 , the pulse sequences described herein are significantly superior to SLIC and pure transverse magnetic field scan methods, where the transverse magnetic field scan at the Lee - Goldburg frame achieves the highest molar polarization.

[0151] Example 4: (1,2-,d 2 )-ethyl acetate polarization MREV-8, polarization BLEW-12, polarization BR-24 and in Lee- Numerical simulation of transverse magnetic field scan at Goldburg frame

[0152] Figure 5 Shows (1,2 - d 2)-The molar polarization of ethyl acetate relative to the polarization MREV-8( Figure 5 “MREV-8adj” in Figure 5 ), the polarization BLEW-12( Figure 5 “BLEW-12adj” in Figure 5 ), the polarization BR-24( Figure 5 “BR-24adj” in Figure 5 ), and an exemplary numerical simulation of the concentration of the transverse magnetic field scan at the Lee-Goldburg frame pulse sequence(

[0153] Example 5: Using a transverse magnetic field scan at the Lee-Goldburg frame for (1- 13 C,d 6 ) dimethyl maleate Experimental demonstration of high molar polarization

[0154] “LG+ scan” in 13 C,d 6 ). The numerical simulation was performed as described herein for Example 1. Simulations were also performed on SLIC and a pure transverse magnetic field scan( 4 “scan” in 6 ), to enable a proper comparison between the pulse sequences described herein and previous pulse sequences. For ease of performing the simulations, the concentration is expressed in units of (2π)Hz. As discussed herein, the concentration can be converted to mM units by multiplying by a proportionality constant. Similarly, the molar polarization is expressed in units of (fractional) polarization multiplied by (2π)Hz, and can be converted to molar polarization (in mM) by multiplying by a proportionality constant. As shown in 13 C,d 6 ), the pulse sequences described herein are significantly superior to SLIC and pure transverse magnetic field scan methods, where the transverse magnetic field scan at the Lee-Goldburg frame achieved the highest molar polarization. 13 C,d 6 ), to enable a proper comparison between the pulse sequences described herein and previous pulse sequences. For ease of performing the simulations, the concentration is expressed in units of (2π)Hz. As discussed herein, the concentration can be converted to mM units by multiplying by a proportionality constant. Similarly, the molar polarization is expressed in units of (fractional) polarization multiplied by (2π)Hz, and can be converted to molar polarization (in mM) by multiplying by a proportionality constant. As shown in

[0155] The systems and methods described herein are used to impart a high molar polarization of up to 450 mM in dimethyl (1- 13 C,d 6 )-maleate. A precursor solution of dimethyl (1- 4 )-maleate is prepared by dissolving 5 mM [Rh(dppb)(COD)]BF 6 catalyst (CAS number: 79255-71-3) into acetone-d 13 C,d 6 ). Different amounts of dimethyl (1- 13 C,d 6 )-acetylenedicarboxylate are mixed for different experiments: each concentration point in the data series provided herein is 20 mM, 40 mM, 80 mM, 160 mM, 320 mM, 640 mM, and 1080 mM. Parahydrogen is generated by an ARS parahydrogen generator filled with an iron catalyst monohydrate, which operates at a temperature of 22 K and produces a gas with a para-enrichment level of approximately 93%.

[0155] Each experiment began with injecting 500 microliters (μL) of solution into a tube, and bubbling para - enriched hydrogen gas through the solution at a pressure of 10 bar under a bias magnetic field of 96 μT. Subsequently, nitrogen gas was bubbled at 10 bar to stop further progression of the reaction. To avoid rapid singlet state decay, 1 H decoupling was provided throughout the bubbling period, and in all experiments, the decoupling was fixed at 30 seconds (s).

[0156] Polarization transfer was performed in two different ways. The first method consisted of a transverse field with an amplitude (relative to 1 H) scanned upward from 0 Hz to 25 Hz, followed by an adiabatic pulse. The pulse was arranged by ramping down the transverse field amplitude with a gradual carrier frequency offset of - 200 Hz within 1 second.

[0157] The second method involved non - resonant driving during polarization transfer such that the effective field θ e was at an angle B e with respect to the bias magnetic field. For the experiments described regarding Figure 6 and Figure 7 , the effective field amplitudes were set to 600 Hz and 400 Hz respectively. After performing the transfer flip pulse by ramping down the transverse field amplitude with a gradual carrier frequency offset of - 200 Hz within 1 second. The polarization transfer was completed by ramping up the modulation of the non - resonant driving field amplitude from 0 Hz to 25 Hz (relative to 1 H). The modulation frequency was set to match the effective field amplitude. To perform an adiabatic pulse along the effective field, the modulation amplitude was ramped down within 1 second, where the gradual modulation frequency offset was - 200 Hz.

[0158] 1 The 1H free induction decay was initiated by a small flip - angle hard pulse with a 20 kHz radio - frequency (RF) amplitude and recorded at a spectral width of 400 ppm with a 131 - point density. All experiments used additional 1H decoupling. The thermal equilibrium 1 H spectrum was recorded at room temperature with a recycle delay of 90 seconds and a 90 - degree flip - angle pulse. When estimating the polarization level, the flip - angle scaling factor was taken into account.

[0159] Figure 6 Shows exemplary 13 C,d 6 ) - dimethyl maleate of hyperpolarized (1 - 1H molar polarization. Data points were acquired by transverse magnetic field scans at the Lee - Goldburg frame (black dots) and amplitude - scanned SLIC (gray dots) pulse sequences. The amplitude - scanned SLIC duration was set to 2 s, and the Lee - Goldburg effective field amplitude was set to 600 Hz. The dashed line represents the linear correlation for a fixed polarization level of 47%. Note that the molar polarization is calculated as polarization times concentration times a factor of two to account for the presence of two polarized protons in dimethyl maleate after PHIP polarization. For clarity, a rescaled inset is provided. As shown in Figure 6 Compared to a molar polarization level of approximately 50 mM using the standard amplitude - scanned SLIC pulse sequence, transverse magnetic field scans at the Lee - Goldburg frame pulse sequence achieved a molar polarization level of up to 450 mM.

[0160] Figure 7 Exemplary hyperpolarized (1 - 13 C,d 6 ) - dimethyl maleate 1 H spin polarization as a function of the effective angle of Lee - Goldburg decoupling is shown. Data points acquired at concentrations of 17 mM and 223 mM are shown in gray and black, respectively. The amplitude - scanned SLIC duration was set to 4 s, and the Lee - Goldburg effective field amplitude was set to 400 Hz. The dashed lines indicate the polarization levels obtained by transverse magnetic field scans at the Lee - Goldburg frame pulse sequence derived in this work at high and low concentrations. The magic angle of approximately 54.7° is indicated. As shown in Figure 7 the polarization is maximized at the magic angle.

[0161] Example 6: Experimental demonstration of the high molar polarization of (1- 13 C,d 6 )-dimethyl maleate using polarized MREV-8

[0162] Figure 8 Exemplary hyperpolarized 13 C - d 6 - dimethyl maleate 1 H spectra acquired at a 9.41 T magnetic field after polarization transfer using the polarization MREV - 8 sequence are shown. After the hyperpolarization experiment, the following thermally polarized spectra were acquired at room temperature. The MREV - 8 sequence was performed in a 200 μT offset magnetic field, the pulse amplitude was set to 400 Hz relative to the 1 H nutation, the free evolution time was set to 0.625 ms, and 30 loops were used, with a total duration of 0.3 s. Hydrogenation was performed by bubbling para - hydrogen at 10 bar for 25 s and nitrogen at 10 bar for 5 s under 1 H continuous - wave decoupling with an amplitude of 3 μT. As shown in Figure 8As shown, for a concentration of about 1 mole (M) = 1,000 mM of 1- 13 C-d 6 -dimethyl maleate, a polarization of about 20% was achieved. Since dimethyl maleate contains two polarized protons after PHIP polarization, this corresponds to a molar polarization of about 400 mM.

[0163] Description of the examples

[0164] Example 1. A method comprising:

[0165] (a) obtaining a solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of at least 50 millimolar (mM).

[0166] Example 2. The method according to Example 1, further comprising, prior to (a), performing a nuclear spin hyperpolarization protocol on the hyperpolarized molecule, thereby imparting the molar polarization to the at least one nucleus.

[0167] Example 3. The method according to Example 2, wherein the nuclear spin hyperpolarization protocol comprises:

[0168] (b) obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1-C═C-R2 or R1-C≡C-R2, wherein R1 and R2 comprise side chains;

[0169] (c) hydrogenating the double bond or the triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R1-CH * -CH * -R2 or R1-CH * ═CH * -R2, wherein H * represents a hydrogen atom derived from parahydrogen added across the double bond or the triple bond; and

[0170] (d) applying a polarization transfer waveform to transfer nuclear spin order from at least one of the hydrogen atoms derived from parahydrogen to the at least one nucleus, thereby imparting nuclear spin hyperpolarization to the at least one nucleus.

[0171] Example 4. The method according to Example 3, wherein the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization generated during the buildup of the nuclear spin hyperpolarization.

[0172] Example 5. The method according to Example 3 or 4, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

[0173] Example 6. The method according to Example 4 or 5, wherein the polarization transfer waveform further comprises a cascaded drive field based on a parameter scan.

[0174] Example 7. The example according to Example 6, wherein the parameter scan comprises a transverse magnetic field (B 1 ) scan.

[0175] Example 8. The method according to any one of Examples 3 to 7, wherein the polarization transfer waveform comprises a B 1 scan at the Lee - Goldburg frame.

[0176] Example 9. The method according to any one of Examples 3 to 7, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarized MREV - 8, polarized BLEW - 12, and polarized BR - 24.

[0177] Example 10. The method according to any one of Examples 3 to 9, wherein (b)-(d) generate the hyperpolarized molecule.

[0178] Example 11. The method according to any one of Examples 3 to 9, further comprising: (e) hydrolyzing the secondary hydrogenated derivative, thereby forming the hyperpolarized molecule.

[0179] Example 12. The method according to Example 10 or 11, further comprising using the hyperpolarized molecule in a nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiment, wherein the hyperpolarized molecule comprises the molecule of interest.

[0180] Example 13. The method according to Example 10 or 11, further comprising: (f) transferring nuclear spin polarization from the hyperpolarized molecule to the molecule of interest; and (g) using the molecule of interest in an NMR or MRI experiment.

[0181] Example 14. The method according to Example 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a para - hydrogen - induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure.

[0182] Example 15. The method according to Example 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by para - hydrogen - induced polarization relayed via a proton exchange (PHIP - X) procedure.

[0183] Example 16. The method according to Example 12 or 13, wherein the molecule of interest comprises a biologically relevant contrast agent.

[0184] Example 17. The method according to Example 16, wherein the biorelevant contrast agent is selected from the group consisting of pyruvate, glutamate, glutamine, lactate, acetate, acetoacetate, zymonate, alanine, fructose, fumarate, bicarbonate, urea, dehydroascorbate, α-ketoglutarate, dihydroxyacetone, glucose, ascorbate, and conjugated acids thereof.

[0185] Example 18. The method according to any one of Examples 1 to 17, wherein the molar polarization comprises the product of the concentration of the at least one nucleus and the nuclear spin polarization of the at least one nucleus.

[0186] Example 19. The method according to any one of Examples 1 to 18, wherein the molar polarization is at least 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM, 340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM, 440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM, 540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM, 640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM, 740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM, 840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM, 940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM or 1,000 mM.

[0187] Example 20. The method according to any one of Examples 1 to 19, wherein the at least one nucleus comprises at least one proton ( 1 H), carbon-13 ( 13 C), nitrogen-15 ( 15N), fluorine-19 ( 19 F) or phosphate-31 ( 31 P) nucleus.

[0188] Example 21. A composition comprising:

[0189] A solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of 50 millimoles (mM).

[0190] Example 22. The composition according to Example 21, wherein the hyperpolarized molecule is generated by performing a nuclear spin hyperpolarization scheme on the hyperpolarized molecule, thereby imparting the molar polarization to the at least one nucleus.

[0191] Example 23. The composition according to Example 22, wherein the nuclear spin hyperpolarization scheme comprises:

[0192] (a) Obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1-C═C-R2 or R1-C≡C-R2, wherein R1 and R2 comprise side chains;

[0193] (b) Hydrogenating the double bond or the triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R1-CH * -CH * -R2 or R1-CH * ═CH * -R2, wherein H * represents a hydrogen atom derived from parahydrogen added across the double bond or the triple bond; and

[0194] (c) Applying a polarization transfer waveform to transfer nuclear spin order from at least one of the hydrogen atoms derived from parahydrogen to the at least one nucleus, thereby imparting nuclear spin hyperpolarization to the at least one nucleus.

[0195] Example 24. The composition according to Example 23, wherein the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization generated during the accumulation of the nuclear spin hyperpolarization.

[0196] Example 25. The composition according to Example 23 or 24, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

[0197] Example 26. The composition according to Example 24 or 25, wherein the polarization transfer waveform further comprises a cascaded drive field based on a parameter scan.

[0198] Example 27. The composition according to Example 26, wherein the parameter scan comprises a transverse magnetic field (B 1 ) scan.

[0199] Example 28. The composition according to any one of Examples 23 to 27, wherein the polarization transfer waveform comprises a B 1 scan at the Lee-Goldburg frame.

[0200] Example 29. The composition according to any one of Examples 23 to 27, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarized MREV-8, polarized BLEW-12, and polarized BR-24.

[0201] Example 30. The composition according to any one of Examples 23 to 29, wherein (a)-(c) generate the hyperpolarized molecule.

[0202] Example 31. The composition according to any one of Examples 23 to 29, wherein the hyperpolarized molecule is further generated by: (d) hydrolyzing the secondary hydrogenated derivative, thereby forming the hyperpolarized molecule.

[0203] Example 32. The composition according to Example 30 or 31, wherein the hyperpolarized molecule is used in nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiments, wherein the hyperpolarized molecule comprises the molecule of interest.

[0204] Example 33. The composition according to Example 31 or 32, wherein the hyperpolarized molecule is used for: (e) transferring nuclear spin polarization from the hyperpolarized molecule to the molecule of interest; and (f) using the molecule of interest in NMR or MRI experiments.

[0205] Example 34. The composition according to Example 33, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a para-hydrogen induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure.

[0206] Example 35. The composition according to Example 33, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by para-hydrogen induced polarization relayed via a proton exchange (PHIP-X) procedure.

[0207] Example 36. The composition according to Example 34 or 35, wherein the molecule of interest comprises a biologically relevant contrast agent.

[0208] Example 37. The composition according to Example 36, wherein the bio-related contrast agent is selected from the group consisting of pyruvate, glutamate, glutamine, lactate, acetate, acetoacetate, ketoisocaproate, alanine, fructose, fumarate, bicarbonate, urea, dehydroascorbate, α-ketoglutarate, dihydroxyacetone, glucose, ascorbate, and conjugated acids thereof.

[0209] Example 38. The composition according to any one of Examples 21 to 37, wherein the molar polarization comprises the product of the concentration of the at least one nucleus and the nuclear spin polarization of the at least one nucleus.

[0210] Example 39. The composition according to any one of Examples 21 to 38, wherein the molar polarization is at least 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM, 340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM, 440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM, 540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM, 640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM, 740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM, 840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM, 940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM or 1,000 mM.

[0211] Example 40. The composition according to any one of Examples 21 to 39, wherein the at least one nucleus comprises at least one proton ( 1 H), carbon-13 ( 13 C), nitrogen-15 ( 15 N), fluorine-19 ( 19(F) or phosphate-31 ( 31 P) nucleus.

Claims

1. A method, comprising: (a) obtaining a solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of at least 50 millimoles (mM).

2. The method according to claim 1, further comprising, prior to (a), performing a nuclear spin hyperpolarization protocol on the hyperpolarized molecule, thereby imparting the molar polarization to the at least one nucleus.

3. The method according to claim 2, wherein the nuclear spin hyperpolarization protocol comprises: (b) obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1-C═C-R2 or R1-C≡C-R2, wherein R1 and R2 comprise side chains; (c) hydrogenating the double bond or the triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R1-CH * -CH * -R2 or R1-CH * =CH * -R2, where H * represents a hydrogen atom derived from parahydrogen added across the double bond or the triple bond; and (d) applying a polarization transfer waveform to transfer nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus, thereby imparting nuclear spin hyperpolarization to the at least one nucleus.

4. The method according to claim 3, wherein the polarization transfer waveform is configured to suppress the dipolar field associated with the magnetization generated during the buildup of the nuclear spin hyperpolarization.

5. The method according to claim 3 or 4, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

6. The method according to claim 4 or 5, wherein the polarization transfer waveform further comprises a cascade drive field based on a parameter scan.

7. The method according to claim 6, wherein the parameter scan includes a scan of a transverse magnetic field (B 1 ).

8. The method according to any one of claims 3 to 7, wherein the polarization transfer waveform comprises B at a Lee-Goldburg frame 1 scan.

9. The method according to any one of claims 3 to 7, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarization MREV-8, polarization BLEW-12, and polarization BR-24.

10. The method according to any one of claims 3 to 9, wherein (b)-(d) produce the hyperpolarized molecule.

11. The method according to any one of claims 3 to 9, further comprising: (e) hydrolyzing the parahydrogenated derivative, thereby forming the hyperpolarized molecule.

12. The method according to claim 10 or 11, further comprising using the hyperpolarized molecule in a nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiment, wherein the hyperpolarized molecule comprises the molecule of interest.

13. The method according to claim 10 or 11, further comprising: (f) transferring nuclear spin polarization from the hyperpolarized molecule to the molecule of interest; and (g) using the molecule of interest in an NMR or MRI experiment.

14. The method according to claim 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure.

15. The method according to claim 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by parahydrogen-induced polarization relayed via a proton exchange (PHIP-X) procedure.

16. A composition comprising: A solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of at least 50 millimoles (mM).

17. The composition according to claim 16, wherein the hyperpolarized molecule is produced by performing a nuclear spin hyperpolarization protocol on the hyperpolarized molecule, thereby imparting the molar polarization to the at least one nucleus.

18. The composition according to claim 17, wherein the nuclear spin hyperpolarization protocol comprises: (a) obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1-C═C-R2 or R1-C≡C-R2, wherein R1 and R2 comprise side chains; (b) Hydrogenating the double bond or the triple bond with para-hydrogen to form a para-hydrogenated derivative of the hyperpolarized molecule, the para-hydrogenated derivative having the form R1-CH * -CH * -R2 or R1-CH * =CH * -R2, where H * represents a hydrogen atom derived from para-hydrogen added across the double bond or the triple bond; and (c) applying a polarization transfer waveform to transfer nuclear spin order from at least one parahydrogen-derived hydrogen atom among the parahydrogen-derived hydrogen atoms to the at least one nucleus, thereby imparting nuclear spin hyperpolarization to the at least one nucleus.

19. The composition according to claim 18, wherein the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization generated during the buildup of the nuclear spin hyperpolarization.

20. The composition according to claim 18 or 19, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

21. The composition according to claim 19 or 20, wherein the polarization transfer waveform further comprises a cascade drive field based on a parameter scan.

22. The composition according to claim 21, wherein the parameter scan comprises a transverse magnetic field (B 1 ) scan.

23. The composition according to any one of claims 18 to 22, wherein the polarization transfer waveform comprises a B at the Lee-Goldburg frame 1 scan.

24. The composition according to any one of claims 18 to 22, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarization MREV-8, polarization BLEW-12, and polarization BR-24.

25. The composition according to any one of claims 18 to 24, wherein (a)-(c) produce the hyperpolarized molecule.

26. The composition according to any one of claims 18 to 24, wherein the hyperpolarized molecule is further produced by: (d) hydrolyzing the parahydrogenated derivative, thereby forming the hyperpolarized molecule.

27. The composition according to claim 25 or 26, wherein the hyperpolarized molecule is used in nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiments, wherein the hyperpolarized molecule comprises the molecule of interest.

28. The composition according to claim 25 or 26, wherein the hyperpolarized molecule is used for: (e) transferring nuclear spin polarization from the hyperpolarized molecule to the molecule of interest; and (f) using the molecule of interest in NMR or MRI experiments.

29. The composition according to claim 28, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure.

30. The composition according to claim 28, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by means of parahydrogen-induced polarization relayed via a proton exchange (PHIP-X) procedure.

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