Hyperpolarized magnetic resonance spectroscopy (HP-MRS) using dynamic nuclear polarization (DNP) is a technique that has greatly enhanced the sensitivity of detecting ¹³C nuclei¹. However, the polarization decays in the liquid state according to the spin-lattice relaxation time (T₁) of the nucleus. Sampling of the signal also destroys polarization, resulting in a limited temporal ability to observe biologically interesting information. There have been several methods attempted to preserve nuclear polarization after dissolution, including converting polarization to a nuclear singlet-state² as well as substituting exchangeable protons on labeled molecules with deuterium^3-5. Nevertheless, accessing the singlet-state can only be achieved with a limited class of chemical structures while deuterating substrates can be prohibitive due to high costs. The purpose of this abstract is to demonstrate that sampling hyperpolarized signals using a permanent magnet at 1 Tesla (1T) can be a simple and cost effective method to significantly increase T₁s without sacrificing signal to noise.¹³C metabolites were prepared for HP according to published reports using a prototype SpinLab (General Electric, Nisakayuna, New York, USA) for approximately 90 minutes before dissolving with appropriate buffers. For bioreactor experiments, cells were resuspended in a sodium alginate solution and extruded through a 23G needle to beads of approximately 500μm in diameter. On the day of imaging, beads were inserted into a 5mm NMR tube. NMR studies were performed on a 1T Magritek Spectrometer (Magritek, San Diego, CA) using a 5mm ¹H/¹³C dual-tuned coil.Figure 1B demonstrates the clear distinction and measurement of the spin-spin coupling between the ¹³C-labeled carbon and the adjacent natural abundance carbons. Excellent signal-to-noise ratios (SNR) enable observation of these scalar couplings within the first scan of the experiment, allowing rapid determination of the chemical environment surrounding the labeled atom. Interestingly, the coupling between carbons and protons is also visible at this field strength by switching off the decoupling function of the spectrometer as evidenced by Figure 1C. To demonstrate that sampling at 1T preserves the T₁ of a variety of molecules, we polarized and dissolved a range of molecules enriched at different functional groups. Table 1 summarizes the T₁ of HP compounds that we have measured at 1T compared to literature values. There was an appreciable lengthening of the T₁ times regardless of the functional group of the labeled ¹³C. In alginate-encapsulated PC3 prostate cancer cells, an injection of hyperpolarized [1-¹³C] pyruvate resulted in the production of [1-¹³C] lactate. Significantly, the lactate signal was visible almost 10 minutes after injection of the HP substrate, suggesting that the T₁-induced decay of the lactate signal was prolonged in an external magnetic field of 1T. The dual-tuned ¹H-¹³C coil of the 1T permanent magnet also permitted the detection of metabolites using proton spectroscopy. We were able to observe peaks of total choline (tCho) and lactate in alginate-encapsulated cells after the application of a water saturation pulse. The presence of high concentrations of tCho in PC3 cells was confirmed by proton NMR spectroscopy on cell extracts using a 600Mhz research magnet.HP MRI has been very informative in many fields including tumor metabolism⁶, cardiac biology⁷ as well as inflammation⁸. We have demonstrated that permanent magnets can function as a viable alternative to superconducting, cryogen-cooled magnets. We believe this study represents the first systematic demonstration that HP MRI can be reliably performed using permanent magnets at 1T. Another significant advantage in using 1T systems is the ability to achieve longer T₁s. We have observed this phenomenon across a number of different molecules with ¹³C labeled at different functional groups. While other methods for lengthening the lifetime of the HP signal have been described, we believe the utilization of a permanent 1T magnet will be the simplest and most cost-effective method of achieving this aim. Sampling HP MRI experiments using permanent magnets is a cheaper alternative to superconducting magnets that will allow widespread adoption of this technology. There are benefits in terms of the ability to observe scalar couplings in HP molecules as well as lengthened T₁s. We also believe that HP experiments in vivo will especially benefit from the lengthened T₁s because the longitudinal relaxation time of HP molecules have been shown to be shorter in vivo as compared to in solution. Future studies at field strengths closer to clinical magnets are essential to predict behavior of HP molecules as more compounds are scheduled for approval in patients.