title: Multiple sclerosis lesion geometry in quantitative susceptibility mapping (QSM) and phase imaging.
abstract: OBJECTIVE
  To demonstrate the phase and quantitative susceptibility mapping (QSM) patterns created by solid and shell spatial distributions of magnetic susceptibility in multiple sclerosis (MS) lesions.
  
  
  METHODS
  Numerical simulations and experimental phantoms of solid- and shell-shaped magnetic susceptibility sources were used to generate magnitude, phase, and QSM images. Imaging of 20 consecutive MS patients was also reviewed for this Institutional Review Board (IRB)-approved MRI study to identify the appearance of solid and shell lesions on phase and QSM images.
  
  
  RESULTS
  Solid and shell susceptibility sources were correctly reconstructed in QSM images, while the corresponding phase images depicted both geometries with shell-like patterns, making the underlying susceptibility distribution difficult to determine using phase alone. In MS patients, of the 60 largest lesions identified on T2 , 30 lesions were detected on both QSM and phase, of which 83% were solid and 17% were shells on QSM, and of which 30% were solid and 70% were shell on phase. Of the 21 shell-like lesions on phase, 76% appeared solid on QSM, 24% appeared shell on QSM. Of the five shell-like lesions on QSM, all were shell-like on phase.
  
  
  CONCLUSIONS
  QSM accurately depicts both solid and shell patterns of magnetic susceptibility, while phase imaging fails to distinguish them.
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Eskreis-Winkler
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Kofi
authors.initials: K
authors.lastname: Deh
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Medimagemetric, LLC, New York, NY, USA.
authors.forename: Tian
authors.initials: T
authors.lastname: Liu
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.|Bioengineering Department, Cornell University, Ithaca, NY, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wisnieff
authors.affiliation: Bioengineering Department, Cornell University, Ithaca, NY, USA.
authors.forename: Moonsoo
authors.initials: M
authors.lastname: Jin
authors.affiliation: Neurology Department, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Gauthier
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.|Bioengineering Department, Cornell University, Ithaca, NY, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Radiology Department, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Pascal
authors.initials: P
authors.lastname: Spincemaille
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology*
keywords: iron; multiple sclerosis; phase; quantitative susceptibility mapping