title: Dynamic Blood Oxygen Level-dependent MR Imaging of Muscle: Comparison of Postocclusive Reactive Hyperemia in Young Smokers and Nonsmokers.
abstract: OBJECTIVE
  The role of early stage functional assessment of muscle blood flow response (MFR) by dynamic muscle blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging is unknown. We investigated the effect of smoking on vascular function according to MFR derived from dynamic muscle BOLD MR imaging during postocclusive reactive hyperemia in young smokers and nonsmokers.
  
  
  METHODS
  Sixteen healthy male volunteers (8 smokers, 8 nonsmokers; mean age, 30.4 ± 4.6 years) underwent BOLD MR imaging of the left calf muscle. During reactive hyperemia provoked by a cuff-compression technique, we measured muscle BOLD (mB) using a 3-tesla single-shot multi-echo gradient-echo echo-planar imaging sequence. The 2 key mB variables in the reactive hyperemic phase that we studied were times to half hyperemic peak (T(1/2peak)) and peak (TTP), each measured from cuff deflation. We used the Welch test to assess differences in these between smokers and nonsmokers.
  
  
  RESULTS
  T(1/2peak) and TTP were significantly longer in smokers (P < 0.05) in reactive hyperemia. T(1/2peak) was 13.8 ± 5.4 s in smokers and 7.6 ± 1.5 s in nonsmokers, and TTP was 67.5 ± 18.8 s in smokers and 45.4 ± 7.1 s in nonsmokers.
  
  
  CONCLUSIONS
  Dynamic BOLD MR imaging of calf muscle during postocclusive reactive hyperemia demonstrated statistically significant differences in T(1/2peak) and TTP between young smokers and nonsmokers, indicating the presence of early stage smoking-related deterioration in MFR.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishii
authors.forename: Atsushi K
authors.initials: AK
authors.lastname: Kono
authors.forename: Mizuho
authors.initials: M
authors.lastname: Nishio
authors.forename: Katsusuke
authors.initials: K
authors.lastname: Kyotani
authors.forename: Kouya
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D006940:Hyperemia / Q000097:blood*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007511:Ischemia; D007866:Leg / Q000098:blood supply; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D012907:Smoking / Q000097:blood*; D055815:Young Adult
chemical_list: D010100:Oxygen