title: MR parameter quantification with magnetization-prepared double echo steady-state (MP-DESS).
abstract: OBJECTIVE
  The mapping of MR relaxation times and proton density has been the subject of research in medical imaging for many years, as it offers the possibility for longitudinal investigation of disease and the correlation with related biochemical processes. The purpose of this study is to provide a fast mapping protocol, which simultaneously acquires MR relaxation times and relative proton density without compromising accuracy and precision.
  
  
  METHODS
  This work presents a novel magnetization-prepared double echo steady-state (MP-DESS) sequence, which was designed to be sensitive to parameter variations of interest, and insensitive to variations of confounding variables. It provides high sensitivity against variations of the MR relaxation times, high acquisition efficiency, and it is insensitive to off-resonance. Accurate phase graph modeling of the MP-DESS signal is used to obtain unbiased parameter estimates.
  
  
  RESULTS
  The approach is validated in phantom and in vivo measurements. A whole-brain acquisition of 1.4-mm isotropic resolution was acquired in 15 min. Comparisons to gold-standard methods suggest a mapping precision of 5% for T1 and M0 , and below 10% for T2.
  
  
  CONCLUSIONS
  A new quantitative imaging technique is introduced that allows fast and isotropic simultaneous MR parameter mapping of T1, T2, and M0.
authors.affiliation: Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich, Juelich, Germany.
authors.forename: Tony
authors.initials: T
authors.lastname: Stöcker
authors.forename: Fabian
authors.initials: F
authors.lastname: Keil
authors.forename: Kaveh
authors.initials: K
authors.lastname: Vahedipour
authors.forename: Daniel
authors.initials: D
authors.lastname: Brenner
authors.forename: Eberhard
authors.initials: E
authors.lastname: Pracht
authors.forename: N Jon
authors.initials: NJ
authors.lastname: Shah
mesh_terms: D000465:Algorithms; D001931:Brain Mapping / Q000379:methods; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011522:Protons; D012680:Sensitivity and Specificity
chemical_list: D011522:Protons
keywords: double echo steady state; extended phase graph; magnetization preparation; qMRI