title: Phase-sensitive sodium B1 mapping.
abstract: Quantitative sodium MRI requires accurate knowledge of factors affecting the sodium signal. One important determinant of sodium signal level is the transmit B(1) field strength. However, the low signal-to-noise ratio typical of sodium MRI makes accurate B(1) mapping in reasonable scan times challenging. A new phase-sensitive B(1) mapping technique has recently been shown to work better than the widely used dual-angle method in low-signal-to-noise ratio situations and over a broader range of flip angles. In this work, the phase-sensitive B(1) mapping technique is applied to sodium, and its performance compared to the dual-angle method through both simulation and phantom studies. The phase-sensitive method is shown to yield higher quality B(1) maps at low signal-to-noise ratio and greater consistency of measurement than the dual-angle method. An in vivo sodium B(1) map of the human breast is also shown, demonstrating the phase-sensitive method's feasibility for human studies.
authors.affiliation: Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah 84602, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Allen
authors.forename: Glen R
authors.initials: GR
authors.lastname: Morrell
authors.forename: Brock
authors.initials: B
authors.lastname: Peterson
authors.forename: Danny
authors.initials: D
authors.lastname: Park
authors.forename: Garry E
authors.initials: GE
authors.lastname: Gold
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Kaggie
authors.forename: Neal K
authors.initials: NK
authors.lastname: Bangerter
mesh_terms: D000328:Adult; D000465:Algorithms; D001940:Breast / Q000033:anatomy & histology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012964:Sodium
chemical_list: D003287:Contrast Media; D012964:Sodium