Comparison of the B0 Field and Shimming in Human Brains at 3T and 7T
Lupo J, Kelley D, Nelson S, Hammond K
University of California
This study introduces ROMP, Reconstruction of Multichannel Phase, a phase-sensitive reconstruction method which can be used to map the B0 field prior to shimming. ROMP mapping is used to demonstrate the increased inhomogeneity of the B0 field at 7T as compared to 3T. An analysis of shimming the field with linear and second order shims shows the need for higher-order shimming at high field strengths or for volumes placed over the sinuses.