Mohammad Mehdi Khalighi1, Laura I. Sacolick2,
Brian K. Rutt3
1Applied Science Lab, GE Healthcare,
Menlo Park, CA, United States; 2Imaging Technologies Lab, General
Electric Global Research, Garching b. Munchen, Germany; 3Department
of Radiology, Stanford University, Stanford, CA
The
Bloch-Siegert method (BS) has been recently introduced as a fast, robust and
accurate method for B1+ mapping. To compare it with
other existing methods, we derived analytical expressions for SNR in BS,
Actual Flip Angle Imaging (AFI) and Double Angle (DA) B1+
maps. Both theoretical and experimental comparisons show that the BS method
has a higher SNR at low flip angles than the other methods, despite the
shorter scan time of the BS method, making it a promising choice for B1+
mapping for parallel transmit pulse design, especially in situations where
there is highly non-uniform B1+ across the object.
Keywords