Design of a Shim Coil Array Matched to the Human Brain Anatomy

This study introduces a novel design method of a shim coil array specifically optimized for whole brain shimming and to compare the performance of the resulting coils to conventional spherical harmonic shimming.

Stream functions (A‐D) of the first four components and box plot of currents.
E, Box plot of standard deviation of the residual field inhomogeneity after different shimming methods for the data in the test set and the residual fields (F) on three typical slices of a representative field map in the test set after shimming using the first (SH1), fourth SH shapes (SH4), and SVD coil with 12 elements (SVD12TO5). — Stream functions (**A‐D**) of the first four components and box plot of currents. E, Box plot of standard deviation of the residual field inhomogeneity after different shimming methods for the data in the test set and the residual fields (F) on three typical slices of a representative field map in the test set after shimming using the first (SH1), fourth SH shapes (SH4), and SVD coil with 12 elements (SVD12TO5).

Stream functions (**A‐D**) of the first four components and box plot of currents.

E, Box plot of standard deviation of the residual field inhomogeneity after different shimming methods for the data in the test set and the residual fields (F) on three typical slices of a representative field map in the test set after shimming using the first (SH1), fourth SH shapes (SH4), and SVD coil with 12 elements (SVD12TO5).

In this work, a design method of a shim coil array specifically optimized for whole brain shimming in humans is proposed. The shim design is based on the stream function method applied to 84 target field maps acquired in 12 normal volunteers in seven different head positions, followed by the singular value decomposition. The leave‐one‐out cross validation is applied to determine the total number of required elements of the coil array. Statistical inference based on a bootstrap approach is introduced to verify the stability of the coil array design. Numerical results are presented to demonstrate the validity of the proposed design approach.

Jia F, Elshatlawy H, Aghaeifar A, Chu YH, Hsu YC, Littin S, Kroboth S, Yu H, Amrein P, Gao X, Yang W, LeVan P, Scheffler K, Zaitsev M.:

Design of a shim coil array matched to the human brain anatomy.

Magn Reson Med. 2020 Apr;83(4):1442-1457.