title: Detection of brown adipose tissue and thermogenic activity in mice by hyperpolarized xenon MRI.
abstract: The study of brown adipose tissue (BAT) in human weight regulation has been constrained by the lack of a noninvasive tool for measuring this tissue and its function in vivo. Existing imaging modalities are nonspecific and intrinsically insensitive to the less active, lipid-rich BAT of obese subjects, the target population for BAT studies. We demonstrate noninvasive imaging of BAT in mice by hyperpolarized xenon gas MRI. We detect a greater than 15-fold increase in xenon uptake by BAT during stimulation of BAT thermogenesis, which enables us to acquire background-free maps of the tissue in both lean and obese mouse phenotypes. We also demonstrate in vivo MR thermometry of BAT by hyperpolarized xenon gas. Finally, we use the linear temperature dependence of the chemical shift of xenon dissolved in adipose tissue to directly measure BAT temperature and to track thermogenic activity in vivo.
authors.affiliation: Department of Physics and Astronomy, Biomedical Research Imaging Center, and rtbranca@unc.edu.
authors.forename: Rosa Tamara
authors.initials: RT
authors.lastname: Branca
authors.affiliation: Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599; and.
authors.forename: Ting
authors.initials: T
authors.lastname: He
authors.affiliation: Department of Physics and Astronomy, Biomedical Research Imaging Center, and.
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Physics and Astronomy.
authors.forename: Carlos S
authors.initials: CS
authors.lastname: Floyd
authors.affiliation: Medical Physics Graduate Program, Duke University, Durham, NC 27708.
authors.forename: Matthew
authors.initials: M
authors.lastname: Freeman
authors.affiliation: Department of Physics and Astronomy.
authors.forename: Christian
authors.initials: C
authors.lastname: White
authors.affiliation: Department of Physics and Astronomy, Biomedical Research Imaging Center, and.
authors.forename: Alex
authors.initials: A
authors.lastname: Burant
mesh_terms: D002001:Adipose Tissue, Brown / Q000098:blood supply / Q000502:physiology*; D000818:Animals; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D013057:Spectrum Analysis; D013696:Temperature; D022722:Thermogenesis / Q000502:physiology*; D014979:Xenon Isotopes
chemical_list: D014979:Xenon Isotopes
keywords: FDG-PET; MRI; brown adipose tissue; hyperpolarized 129Xe; thermometry