title: Microvascular abnormality in relapsing-remitting multiple sclerosis: perfusion MR imaging findings in normal-appearing white matter.
abstract: OBJECTIVE
  To prospectively determine hemodynamic changes in the normal-appearing white matter (NAWM) of patients with relapsing-remitting multiple sclerosis (RR-MS) by using dynamic susceptibility contrast material-enhanced perfusion magnetic resonance (MR) imaging.
  
  
  METHODS
  Conventional MR imaging (which included acquisition of pre- and postcontrast transverse T1-weighted, fluid-attenuated inversion recovery, and T2-weighted images) and dynamic susceptibility contrast-enhanced T2*-weighted MR imaging were performed in 17 patients with RR-MS (five men and 12 women; median age, 38.4 years; age range, 27.6-56.9 years) and 17 control patients (seven men and 10 women; median age, 42.0 years; age range, 18.7-62.5 years). Absolute cerebral blood volume (CBV), absolute cerebral blood flow (CBF), and mean transit time (MTT) (referenced to an arterial input function by using an automated method) were determined in periventricular, intermediate, and subcortical regions of NAWM at the level of the lateral ventricles. Least-squares regression analysis (controlled for age and sex) was used to compare perfusion measures in each region between patients with RR-MS and control patients. Repeated-measures analysis of variance and the Tukey honestly significant difference test were used to perform pairwise comparison of brain regions in terms of each perfusion measure.
  
  
  RESULTS
  Each region of NAWM in patients with RR-MS had significantly decreased CBF (P <.005) and prolonged MTT (P <.001) compared with the corresponding region in control patients. No significant differences in CBV were found between patients with RR-MS and control patients in any of the corresponding areas of NAWM examined. In control patients, periventricular NAWM regions had significantly higher CBF (P =.03) and CBV (P =.04) than did intermediate NAWM regions. No significant regional differences in CBF, CBV, or MTT were found in patients with RR-MS.
  
  
  CONCLUSIONS
  The NAWM of patients with RR-MS shows decreased perfusion compared with that of controls.
authors.affiliation: Departments of Radiology and Neurology, New York University Medical Center, MRI Department, Schwartz Building, Basement HCC, 530 First Avenue, New York, NY 10016, USA. lawm01@med.nyu.edu
authors.forename: Meng
authors.initials: M
authors.lastname: Law
authors.forename: Amit M
authors.initials: AM
authors.lastname: Saindane
authors.forename: Yulin
authors.initials: Y
authors.lastname: Ge
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.forename: Glyn
authors.initials: G
authors.lastname: Johnson
authors.forename: Lois J
authors.initials: LJ
authors.lastname: Mannon
authors.forename: Joseph
authors.initials: J
authors.lastname: Herbert
authors.forename: Robert I
authors.initials: RI
authors.lastname: Grossman
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D001810:Blood Volume; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA