Quantitative oxygen extraction fraction from 7-Tesla MRI phase: reproducibility and application in multiple sclerosis

J Cereb Blood Flow Metab. 2015 Jan;35(1):131-9. doi: 10.1038/jcbfm.2014.187. Epub 2014 Oct 29.


Quantitative oxygen extraction fraction (OEF) in cortical veins was studied in patients with multiple sclerosis (MS) and healthy subjects via magnetic resonance imaging (MRI) phase images at 7 Tesla (7 T). Flow-compensated, three-dimensional gradient-echo scans were acquired for absolute OEF quantification in 23 patients with MS and 14 age-matched controls. In patients, we collected T2*-weighted images for characterization of white matter, deep gray matter, and cortical lesions, and also assessed cognitive function. Variability of OEF across readers and scan sessions was evaluated in a subset of volunteers. OEF was averaged from 2 to 3 pial veins in the sensorimotor, parietal, and prefrontal cortical regions for each subject (total of ~10 vessels). We observed good reproducibility of mean OEF, with intraobserver coefficient of variation (COV)=2.1%, interobserver COV=5.2%, and scan-rescan COV=5.9%. Patients exhibited a 3.4% reduction in cortical OEF relative to controls (P=0.0025), which was not different across brain regions. Although oxygenation did not relate with measures of structural tissue damage, mean OEF correlated with a global measure of information processing speed. These findings suggest that cortical OEF from 7-T MRI phase is a reproducible metabolic biomarker that may be sensitive to different pathologic processes than structural MRI in patients with MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / blood supply
  • Brain / metabolism*
  • Brain / pathology
  • Case-Control Studies
  • Cerebral Veins / metabolism
  • Cognition / physiology
  • Energy Metabolism*
  • Female
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Multiple Sclerosis / metabolism*
  • Multiple Sclerosis / pathology*
  • Multiple Sclerosis / psychology
  • Neuropsychological Tests
  • Oxygen / blood
  • Oxygen / metabolism*
  • Prospective Studies
  • Reproducibility of Results


  • Oxygen