title: Rapid field-cycling MRI using fast spin-echo.
abstract: OBJECTIVE
  Fast field-cycling MRI (FFC-MRI) is a technique that promises to expand upon the diagnostic capabilities of conventional MRI by allowing the main field, B0 , to be varied during a pulse sequence, thus allowing access to new types of endogenous contrast. However, this necessitates longer scan times, which can limit the technique's application to clinical research. In this paper, an adaptation of the fast spin-echo (FSE) pulse sequence for use with FFC-MRI is presented, known as field-cycling fast spin-echo (FC-FSE). This technique allows much faster image acquisition, thus shortening scan times significantly.
  
  
  METHODS
  Image quality and relaxometric accuracy were assessed by comparison of phantom images with data obtained using conventional techniques. As proof of principle, relaxometric images were obtained from the thighs of a human volunteer.
  
  
  RESULTS
  Image quality remains good for speedup factors of up to 4-fold. The accuracy of relaxometry data is in good agreement with conventional techniques. Results from a volunteer study were encouraging, demonstrating that the technique is sensitive enough to detect quadrupole peaks in vivo.
  
  
  CONCLUSIONS
  The technique has been demonstrated in phantom experiments with little loss of image quality or relaxometric accuracy. Initial in-vivo results pave the way for future clinical studies.
authors.affiliation: Aberdeen Biomedical Imaging Centre, Musculoskeletal group, School of Medicine and Dentistry, University of Aberdeen, United Kingdom.
authors.forename: P James
authors.initials: PJ
authors.lastname: Ross
authors.forename: Lionel M
authors.initials: LM
authors.lastname: Broche
authors.forename: David J
authors.initials: DJ
authors.lastname: Lurie
mesh_terms: D000328:Adult; D000465:Algorithms; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: dispersion curve; field-cycling; quadrupole peaks; relaxometric imaging