title: An investigation of pipeline materials for continuous hyperpolarized 129Xe gas spectroscopy.
abstract: In order to establish a continuous hyperpolarized xenon-129 (HP-129Xe) gas delivery system for MR imaging, the effect of the metallic materials in the gas pipeline on the signal intensity was investigated. In the gas pipeline, an appropriate surface is needed to minimize wall relaxation by the HP-129Xe gas caused by the interaction between the HP gas and the surface, which can lead to signal loss. Although Pyrex glass is a popular material for the HP gas chamber, it is fragile under heat or physical stress. In this study, five stainless steel tubes (STs) prepared with different surface film-forming processes were examined. The MR signal intensities of HP-129Xe gas that passed through each tube were then compared. The film passivated by iron fluoride maintained the highest level of hyperpolarization, whereas that passivated by chromium oxide maintained the lowest. A ST with an appropriate passive film may be a useful alternative to a Pyrex glass pipeline.
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Osaka 563-8577, Japan. moyoko-saitou@aist.go.jp
authors.forename: Moyoko
authors.initials: M
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Hiraga
authors.forename: Mineyuki
authors.initials: M
authors.lastname: Hattori
authors.forename: Shumei
authors.initials: S
authors.lastname: Murakami
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Nakai
mesh_terms: D004867:Equipment Design; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D005741:Noble Gases; D014979:Xenon Isotopes
chemical_list: D005741:Noble Gases; D014979:Xenon Isotopes