Steven Paul Allen1, Glen R. Morrell2,
  Brock Peterson1, Daniel Park1, Josh Kaggie2,
  Ernesto Staroswiecki3, Neal K. Bangerter1
1Department of Electrical and Computer
  Engineering, Brigham Young University, Provo, UT, United States; 2Department
  of Radiology, University of Utah, Salt Lake City, UT, United States; 3Department
  of Radiology, Stanford University, Stanford, CA, United States
Accurate
  quantification of tissue sodium concentration is an important component of
  several potential applications of sodium MRI.
Quantitative analysis of sodium concentrations requires accurate
  measurement of B1. However, the low
  SNR typical in sodium MRI makes accurate B1 mapping in a reasonable time
  challenging. Phase-sensitive B1
  mapping techniques are particularly robust in low SNR environments. In this work, we apply phase sensitive B1
  mapping to sodium MRI, and compare it to a standard dual angle B1 mapping
  method. The phase sensitive method is
  shown to perform much better than the dual angle method, allowing rapid
  acquisition of reliable sodium B1 maps.
Keywords