title: Two-dimensional and three-dimensional oxygen mapping by 3He-MRI validation in a lung phantom.
abstract: The aim of this study was to validate oxygen-sensitive 3He-MRI in noninvasive determination of the regional, two- and three-dimensional distribution of oxygen partial pressure. In a gas-filled elastic silicon ventilation bag used as a lung phantom, oxygen sensitive two- and three-dimensional 3He-MRI measurements were performed at different oxygen concentrations which had been equilibrated in a range of normal and pathologic values. The oxygen partial pressure distribution was determined from 3He-MRI using newly developed software allowing for mapping of oxygen partial pressure. The reference bulk oxygen partial pressure inside the phantom was measured by conventional respiratory gas analysis. In two-dimensional measurements, image-based and gas-analysis results correlated with r=0.98; in three-dimensional measurements the between-methods correlation coefficient was r=0.89. The signal-to-noise ratio of three-dimensional measurements was about half of that of two-dimensional measurements and became critical (below 3) in some data sets. Oxygen-sensitive 3He-MRI allows for noninvasive determination of the two- and three-dimensional distribution of oxygen partial pressure in gas-filled airspaces.
authors.affiliation: Department of Radiology, Johannes Gutenberg University Hospital, Langenbeckstrasse 1, 55131, Mainz, Germany. kgast@radiologie.klinik.uni-mainz.de
authors.forename: Klaus Kurt
authors.initials: KK
authors.lastname: Gast
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Schreiber
authors.forename: Annette
authors.initials: A
authors.lastname: Herweling
authors.forename: Frank
authors.initials: F
authors.lastname: Lehmann
authors.forename: Gabor
authors.initials: G
authors.lastname: Erdös
authors.forename: Joerg
authors.initials: J
authors.lastname: Schmiedeskamp
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Balthasar
authors.initials: B
authors.lastname: Eberle
mesh_terms: D006371:Helium; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D001239:Inhalation / Q000502:physiology; D007554:Isotopes; D008168:Lung / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000008:administration & dosage; D010101:Oxygen Consumption / Q000502:physiology*; D010313:Partial Pressure; D019047:Phantoms, Imaging
chemical_list: D007554:Isotopes; D006371:Helium; D010100:Oxygen