title: Quantitative tissue oxygen measurement in multiple organs using 19F MRI in a rat model.
abstract: Measurement of individual organ tissue oxygen levels can provide information to help evaluate and optimize medical interventions in many areas including wound healing, resuscitation strategies, and cancer therapeutics. Echo planar (19) F MRI has previously focused on tumor oxygen measurement at low oxygen levels (pO(2)) <30 mmHg. It uses the linear relationship between spin-lattice relaxation rate (R(1)) of hexafluorobenzene (HFB) and pO(2). The feasibility of this technique for a wider range of pO(2) values and individual organ tissue pO(2) measurement was investigated in a rat model. Spin-lattice relaxation times (T(1) = 1/R(1)) of hexafluorobenzene were measured using (19) F saturation recovery echo planar imaging. Initial in vitro studies validated the linear relationship between R(1) and pO(2) from 0 to 760 mmHg oxygen partial pressure at 25, 37, and 41°C at 7 Tesla for hexafluorobenzene. In vivo experiments measured rat tissue oxygen (ptO2) levels of brain, kidney, liver, gut, muscle, and skin during inhalation of both 30 and 100% oxygen. All organ ptO(2) values significantly increased with hyperoxia (P < 0.001). This study demonstrates that (19) F MRI of hexafluorobenzene offers a feasible tool to measure regional ptO2 in vivo, and that hyperoxia significantly increases ptO2 of multiple organs in a rat model.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143-0464, USA.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Liu
authors.forename: Sameer J
authors.initials: SJ
authors.lastname: Shah
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Wilmes
authors.forename: John
authors.initials: J
authors.lastname: Feiner
authors.forename: Vikram D
authors.initials: VD
authors.lastname: Kodibagkar
authors.forename: Michael F
authors.initials: MF
authors.lastname: Wendland
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Mason
authors.forename: Nola
authors.initials: N
authors.lastname: Hylton
authors.forename: Harriet W
authors.initials: HW
authors.lastname: Hopf
authors.forename: Mark D
authors.initials: MD
authors.lastname: Rollins
mesh_terms: D000818:Animals; D017352:Echo-Planar Imaging / Q000379:methods*; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014781:Viscera / Q000502:physiology*
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D010100:Oxygen