title: Cerebral white matter: technical development and clinical applications of effective magnetization transfer (MT) power concepts for high-power, thin-section, quantitative MT examinations.
abstract: OBJECTIVE
  To evaluate white matter disorders with magnetization transfer (MT) techniques.
  
  
  METHODS
  In 46 healthy volunteers and 46 clinical patients, MT Z spectra were obtained with various continuous-wave-equivalent MT powers (B1CW) and frequency offsets.
  
  
  RESULTS
  With B1CW of 270 Hz and 4,000-Hz frequency offset, the MT ratio of normal callosal white matter was 59.2% +/- 1.5 (standard deviation), with less than 5% contribution from direct saturation and spin locking. A small statistically significant (P < .01) regional variation in normal white matter was seen. Plaques in MS patients had a broad (or wide) range of MT ratios; normal appearing white matter had a slightly reduced MT ratio. Vasogenic edema had a minimal effect on MT ratio, and radiation necrosis showed prominent reductions in MT ratio.
  
  
  CONCLUSIONS
  High MT power techniques can expand the dynamic range of MT ratios, maintain a relatively pure MT effect, and be used effectively in MT imaging to evaluate white matter disorders.
authors.affiliation: Department of Radiology, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, OH 44109-1998, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Finelli
authors.forename: G C
authors.initials: GC
authors.lastname: Hurst
authors.forename: P
authors.initials: P
authors.lastname: Amantia
authors.forename: R P
authors.initials: RP
authors.lastname: Gullapali
authors.forename: A
authors.initials: A
authors.lastname: Apicella
mesh_terms: D001921:Brain / Q000033:anatomy & histology / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D016022:Case-Control Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009103:Multiple Sclerosis / Q000473:pathology*; D019047:Phantoms, Imaging