title: XeNA: an automated 'open-source' (129)Xe hyperpolarizer for clinical use.
abstract: Here we provide a full report on the construction, components, and capabilities of our consortium's "open-source" large-scale (~1L/h) (129)Xe hyperpolarizer for clinical, pre-clinical, and materials NMR/MRI (Nikolaou et al., Proc. Natl. Acad. Sci. USA, 110, 14150 (2013)). The 'hyperpolarizer' is automated and built mostly of off-the-shelf components; moreover, it is designed to be cost-effective and installed in both research laboratories and clinical settings with materials costing less than $125,000. The device runs in the xenon-rich regime (up to 1800Torr Xe in 0.5L) in either stopped-flow or single-batch mode-making cryo-collection of the hyperpolarized gas unnecessary for many applications. In-cell (129)Xe nuclear spin polarization values of ~30%-90% have been measured for Xe loadings of ~300-1600Torr. Typical (129)Xe polarization build-up and T1 relaxation time constants were ~8.5min and ~1.9h respectively under our spin-exchange optical pumping conditions; such ratios, combined with near-unity Rb electron spin polarizations enabled by the high resonant laser power (up to ~200W), permit such high PXe values to be achieved despite the high in-cell Xe densities. Importantly, most of the polarization is maintained during efficient HP gas transfer to other containers, and ultra-long (129)Xe relaxation times (up to nearly 6h) were observed in Tedlar bags following transport to a clinical 3T scanner for MR spectroscopy and imaging as a prelude to in vivo experiments. The device has received FDA IND approval for a clinical study of chronic obstructive pulmonary disease subjects. The primary focus of this paper is on the technical/engineering development of the polarizer, with the explicit goals of facilitating the adaptation of design features and operative modes into other laboratories, and of spurring the further advancement of HP-gas MR applications in biomedicine.
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, TN, 37232, United States; Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL. Electronic address: peter.nikolaou@vanderbilt.edu.
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Nikolaou
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, TN, 37232, United States; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, United States.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Coffey
authors.affiliation: Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Walkup
authors.affiliation: Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL.
authors.forename: Brogan M
authors.initials: BM
authors.lastname: Gust
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, NG7 2RD, Nottingham, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Whiting
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, NG7 2RD, Nottingham, UK.
authors.forename: Hayley
authors.initials: H
authors.lastname: Newton
authors.affiliation: Department of Radiology, Brigham & Women's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Iga
authors.initials: I
authors.lastname: Muradyan
authors.affiliation: Department of Radiology, Brigham & Women's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Mikayel
authors.initials: M
authors.lastname: Dabaghyan
authors.affiliation: Department of Physics, Southern Illinois University, Carbondale, IL.
authors.forename: Kaili
authors.initials: K
authors.lastname: Ranta
authors.affiliation: Graduate School Central Research Shop, Southern Illinois University, Carbondale, IL.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Moroz
authors.affiliation: MGH/A.A. Martinos Center for Biomedical Imaging, Boston, MA; Department of Physics, Harvard University, Cambridge, MA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Rosen
authors.affiliation: Department of Radiology, Brigham & Women's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Patz
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, NG7 2RD, Nottingham, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Barlow
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, TN, 37232, United States; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, United States; Department of Biochemistry, Vanderbilt University, Nashville, TN, 37205, United States.
authors.forename: Eduard Y
authors.initials: EY
authors.lastname: Chekmenev
authors.affiliation: Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL. Electronic address: bgoodson@chem.siu.edu.
authors.forename: Boyd M
authors.initials: BM
authors.lastname: Goodson
mesh_terms: D004867:Equipment Design; D004868:Equipment Failure; D017022:Flow Injection Analysis / Q000295:instrumentation*; D006361:Heating / Q000295:instrumentation*; D007553:Isotope Labeling / Q000295:instrumentation*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000302:isolation & purification; D012371:Robotics / Q000295:instrumentation*; D013057:Spectrum Analysis / Q000295:instrumentation*; D014979:Xenon Isotopes / Q000138:chemical synthesis* / Q000302:isolation & purification*
chemical_list: D019275:Radiopharmaceuticals; D014979:Xenon Isotopes
keywords: Hyperpolarization; Laser-polarized xenon; Lung imaging; MRI; Optical pumping