title: Determination of oxygen extraction ratios by magnetic resonance imaging.
abstract: The oxygen extraction ratio (OER) of a tissue describes the interplay between oxygen delivery and consumption and, as such, directly reflects the viability and activity of any organ. It is shown that OER can be quantified using a single magnetic resonance imaging observable, namely the relaxation time T2 of venous blood draining from the tissue. This principle is applied to study local OER changes in the brain on visual stimulation in humans, unambiguously demonstrating a mismatch between changes in blood flow and oxygen metabolism on activation.
authors.affiliation: Department of Radiology, Johns Hopkins University Medical School, Baltimore, Maryland 21205, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Oja
authors.forename: J S
authors.initials: JS
authors.lastname: Gillen
authors.forename: R A
authors.initials: RA
authors.lastname: Kauppinen
authors.forename: M
authors.initials: M
authors.lastname: Kraut
authors.forename: P C
authors.initials: PC
authors.lastname: van Zijl
mesh_terms: D001921:Brain / Q000098:blood supply / Q000502:physiology*; D002560:Cerebrovascular Circulation; D006400:Hematocrit; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D010775:Photic Stimulation
chemical_list: D010100:Oxygen