title: Measure of magnetization transfer in multiple sclerosis demyelinating plaques, white matter ischemic lesions, and edema.
abstract: OBJECTIVE
  To define the percentage of magnetization transfer of multiple sclerosis (MS) plaques, ischemic white matter lesions, and vasogenic edema to determine whether this measurement can help differentiate these entities.
  
  
  METHODS
  Findings were compared in 25 patients with proved MS, 20 patients with white matter ischemic lesions, and 72 patients with white matter edema (caused by tumors, infections, or acute/subacute infarctions) in the periventricular system, centrum semiovale, and subcortical white matter. Magnetization transfer was performed using an on-resonance binomial pulse. The percentage of magnetization transfer of the normal white matter was also calculated.
  
  
  RESULTS
  Magnetization transfer was significantly higher in white matter ischemic lesions (range, 31% to 38%; mean, 34% +/- 0.6%) than in demyelinating plaques of MS (range, 19% to 28%; mean, 22.5% +/- 1%) and in edema (range, 29% to 37%; mean, 30.2% +/- 0.4%). No statistical difference in percentage of magnetization transfer was found among lesions in the periventricular system (34% +/- 0.6%), centrum semiovale (35% +/- 0.5%), or subcortical white matter (33% +/- 0.6%), or in vasogenic edema associated with tumors, infections, or infarction.
  
  
  CONCLUSIONS
  Differences in magnetization transfer suggest less change of demyelination in white matter ischemic lesions than in MS plaques and are significantly different in this respect from similar MS plaques. Magnetization transfer of edema was less than that of normal white matter or fell between ischemic abnormalities and MS plaques. Percentages of magnetization transfer below the mid-20% range is highly suggestive of demyelination. Vasogenic edema, our surrogate for increased water content of white matter, caused a decrease in the percentage of magnetization transfer.
authors.affiliation: Department of Radiology, Stanford University School of Medicine, CA 94305, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Mehta
authors.forename: G B
authors.initials: GB
authors.lastname: Pike
authors.forename: D R
authors.initials: DR
authors.lastname: Enzmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000175:diagnosis*; D002545:Brain Ischemia / Q000175:diagnosis*; D001932:Brain Neoplasms / Q000175:diagnosis; D002540:Cerebral Cortex / Q000473:pathology; D002544:Cerebral Infarction / Q000175:diagnosis; D002552:Cerebral Ventricles / Q000473:pathology; D003711:Demyelinating Diseases / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*