Abstract #2745

Impact of Three B1 Mapping Techniques on Variable Flip Angle T1 Measurements

Christine Lucas Tardif¹, Nikola Stikov¹, Ives R. Levesque², G. Bruce Pike¹

¹McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, Quebec, Canada; ²Department of Electrical Engineering, Stanford University, Stanford, CA, United States

Variable flip angle (VFA) T1 mapping has become a popular tool to estimate T1 times in vivo due to its time-efficient high-resolution 3D coverage. For accurate T1 estimates at 3 Tesla, the acquisition of a B1 map is essential to correct the nominal flip angles. This work evaluates the impact of three published B1 mapping techniques (the 2D double angle method (DAM), 3D actual flip angle imaging (AFI) and 3D Bloch-Siegert shift (BS)) to correct VFA T1 measurements in phantoms. Optimally spoiled VFA T1 mapping with DAM B1 correction yields the most accurate results. The errors in AFI and BS B1 maps result in broadening and/or shifting of the T1 histograms.