The Impact of Oblique Slicing and Shim Inclusions on Dynamically Shimmed Global Homogeneity
Koch K, McIntyre S, Nixon T, Rothman D, de Graaf R
Dynamic shim updating (DSU) is a method used to improve global homogeneity through updating of locally optimized shim settings during a multi-volume acquisition. Given the established dependencies of static shimming on higher order shim inclusions and oblique slicing angle, we investigated the impact of these parameters on DSU-utilized global homogeneity. Oblique DSU is complicated by non-obvious shim degeneracies in oblique imaging planes. A method was thus developed to obliquely apply DSU using functional degeneracy analysis. Simulated shimming of measured data was then performed with this method as a function of single-oblique slicing angle and shim inclusion.