title: Spectrally resolved fully phase-encoded three-dimensional fast spin-echo imaging.
abstract: OBJECTIVE
  To develop and test the feasibility of a spectrally resolved fully phase-encoded (SR-FPE) three-dimensional fast spin-echo technique and to demonstrate its application for distortion-free imaging near metal and chemical species separation.
  
  
  METHODS
  In separate scans at 1.5 T, a hip prosthesis phantom and a sphere filled with gadolinium solution were imaged with SR-FPE and compared to conventional three-dimensional-fast spin-echo. Spectral modeling was performed on the SR-FPE data to generate the following parametric maps: species-specific signal (ρspecies), B0 field inhomogeneity, and R*2. The prosthesis phantom was also scanned using a 16-channel coil at 1.5 T. The fully sampled k-space data were retrospectively undersampled to demonstrate the feasibility of parallel imaging acceleration in all three phase-encoding directions, in combination with corner-cutting and half-Fourier sampling. Finally, SR-FPE was performed with an acetone/water/oil phantom to test chemical species separation.
  
  
  RESULTS
  High quality distortion-free images and parametric maps were generated from SR-FPE. A 4 h SR-FPE scan was retrospectively accelerated to 12 min while preserving spectral information and 7.5 min without preserving spectral data. Chemical species separation was demonstrated in the acetone/water/oil phantom.
  
  
  CONCLUSIONS
  This work demonstrates the feasibility of SR-FPE to perform chemical species separation and spectrally resolved imaging near metal without distortion, in scan times appropriate for the clinical setting.
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Artz
authors.forename: Diego
authors.initials: D
authors.lastname: Hernando
authors.forename: Valentina
authors.initials: V
authors.lastname: Taviani
authors.forename: Alexey
authors.initials: A
authors.lastname: Samsonov
authors.forename: Jean H
authors.initials: JH
authors.lastname: Brittain
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D044962:Data Compression / Q000379:methods*; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D013113:Spin Labels; C064572:gadobenic acid; D008536:Meglumine