Dynamic Bo Shimming at 7 Tesla

Introduction Dynamic Shimming is a technique for obtaining optimal Bo field homogeneity over a volume by updating the shim coil and gradient currents for every slice in a multislice acquisition in real time [1, 2]. Dynamic shimming can produce better field homogeneity within each slice than global volume shimming methods. It can therefore reduce signal losses and geometric distortions and can be especially useful in fast T2* weighted imaging sequences such as EPI and in multislice spectroscopic imaging. We have implemented dynamic shimming on a human 7T system. Results with human brain imaging and an evaluation of the improvements made are presented.