title: The change in cerebrovascular reactivity between 3 T and 7 T measured using graded hypercapnia.
abstract: Mapping cerebrovascular reactivity (CVR) to hypercapnia is important both clinically and for improved understanding of the haemodynamic properties of the BOLD effect. In this work, BOLD/R2 CVR was investigated by using a device which provided small, repeatable and stable steps in PETCO2, whilst maintaining a steady PETO2 level. Significant CVR was observed in both grey and white matter at both 3 and 7 T, whilst an approximately linear relationship found between R2 CVR and field strength has implications for BOLD models and calibration. Grey matter R2 CVR was 0.066+/-0.004 s(-1) mm Hg(-1) at 3 T and 0.141+/-0.008 s(-1) mm Hg(-1) at 7 T. White matter R2 CVR was 0.021+/-0.003 s(-1) mm Hg(-1) at 3 T and 0.040+/-0.007 s(-1) mm Hg(-1) at 7 T.
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Driver
authors.forename: Nicholas
authors.initials: N
authors.lastname: Blockley
authors.forename: Joseph
authors.initials: J
authors.lastname: Fisher
authors.forename: Susan
authors.initials: S
authors.lastname: Francis
authors.forename: Penny
authors.initials: P
authors.lastname: Gowland
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000502:physiology; D001931:Brain Mapping / Q000295:instrumentation* / Q000379:methods*; D002138:Calibration; D002245:Carbon Dioxide / Q000032:analysis*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology; D010100:Oxygen / Q000032:analysis* / Q000097:blood; D010101:Oxygen Consumption; D012119:Respiration; D013997:Time Factors; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen