title: Hyperpolarized (129) Xe MRI using isobutene as a new quenching gas.
abstract: The use of a quenching gas, isobutene, with a low vapor pressure was investigated to enhance the utility of hyperpolarized (129) Xe (HP Xe) MRI. Xenon mixed with isobutene was hyperpolarized using a home-built apparatus for continuously producing HP Xe. The isobutene was then readily liquefied and separated almost totally by continuous condensation at about 173 K, because the vapor pressure of isobutene (0.247 kPa) is much lower than that of Xe (157 kPa). Finally, the neat Xe gas was continuously delivered to mice by spontaneous inhalation. The HP Xe MRI was enhanced twofold in polarization level and threefold in signal intensity when isobutene was adopted as the quenching gas instead of N2 . The usefulness of the HP Xe MRI was verified by application to pulmonary functional imaging of spontaneously breathing mice, where the parameters of fractional ventilation (ra ) and gas exchange (fD ) were evaluated, aiming at future extension to preclinical studies. This is the first application of isobutene as a quenching gas for HP Xe MRI.
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Hodono
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Imai
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Kawamura
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Okumura
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. kimura@sahs.med.osaka-u.ac.jp.
authors.forename: Atsuomi
authors.initials: A
authors.lastname: Kimura
mesh_terms: D000280:Administration, Inhalation; D000475:Alkenes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D003287:Contrast Media; D005740:Gases; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000494:pharmacology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014979:Xenon Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D000475:Alkenes; D003287:Contrast Media; D005740:Gases; D019275:Radiopharmaceuticals; D014979:Xenon Isotopes; C008176:isobutylene
keywords: fractional ventilation; gas exchange; hyperpolarized 129Xe; isobutene; quenching gas