title: Magnetization transfer in lamellar liquid crystals.
abstract: OBJECTIVE
  This study examines the relationship between quantitative magnetization transfer (qMT) parameters and the molecular composition of a model lamellar liquid crystal (LLC) system composed of 1-decyl alcohol (decanol), sodium dodecyl sulfate (SDS), and water.
  
  
  METHODS
  Samples were made within a stable lamellar mesophase to provide different ratios of total semisolid protons (SDS + decanol) to water protons. Data were collected as a function of radiofrequency power, frequency offset, and temperature. qMT parameters were estimated by fitting a standard model to the data. Fitting results of four different semisolid line shapes were compared.
  
  
  RESULTS
  A super-Lorentzian line shape for the semisolid component provided the best fit. The estimated amount of semisolids was proportional to the ratio of decanol-to-water protons. Other qMT parameters exhibited nonlinear dependence on sample composition. Magnetization transfer ratio (MTR) was a linear function of the semisolid fraction over a limited range of decanol concentration.
  
  
  CONCLUSIONS
  In LLC samples, MT between semisolid and water originates from intramolecular nOe among decanol aliphatic chain protons followed by proton exchange between decanol hydroxyl and water. Exchange kinetics is influenced by SDS, although SDS protons do not participate in MT. These studies provide clinically relevant range of semisolid fraction proportional to detected MTR.
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Dariya I
authors.initials: DI
authors.lastname: Malyarenko
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Zimmermann
authors.forename: Jeremy
authors.initials: J
authors.lastname: Adler
authors.forename: Scott D
authors.initials: SD
authors.lastname: Swanson
mesh_terms: D005233:Fatty Alcohols / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008962:Models, Theoretical; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*
chemical_list: D005233:Fatty Alcohols; D011522:Protons; D012967:Sodium Dodecyl Sulfate; C029383:n-decyl alcohol
keywords: MRI; MT phantom; magnetization transfer; super-Lorentzian