title: Slice profile and B1corrections in 2D magnetic resonance fingerprinting.
abstract: The goal of this study is to characterize and improve the accuracy of 2D magnetic resonance fingerprinting (MRF) scans in the presence of slice profile (SP) and B1imperfections, which are two main factors that affect quantitative results in MRF.
  
  
  
  The SP and B1imperfections are characterized and corrected separately. The SP effect is corrected by simulating the radiofrequency pulse in the dictionary, and the B1is corrected by acquiring a B1map using the Bloch-Siegert method before each scan. The accuracy, precision, and repeatability of the proposed method are evaluated in phantom studies. The effects of both SP and B1imperfections are also illustrated and corrected in the in vivo studies.
  
  
  
  The SP and B1corrections improve the accuracy of the T1and T2values, independent of the shape of the radiofrequency pulse. The T1and T2values obtained from different excitation patterns become more consistent after corrections, which leads to an improvement of the robustness of the MRF design.
  
  
  
  This study demonstrates that MRF is sensitive to both SP and B1effects, and that corrections can be made to improve the accuracy of MRF with only a 2-s increase in acquisition time. Magn Reson Med 78:1781-1789, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Ma
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Coppo
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Debra F
authors.initials: DF
authors.lastname: McGivney
authors.affiliation: Biomedical Engineering Department, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Shivani
authors.initials: S
authors.lastname: Pahwa
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Gulani
authors.affiliation: Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Griswold
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging
keywords: B1 correction; MR fingerprinting; T1; T2; slice profile correction