Simulation of B0 Magnetic Field Conditions in the Human Heart for Improved B0 Shimming in Cardiovascular MRI

Abstract

Motivation: Balanced SSFP sequences in cardiovascular MRI suffer from dark band artifacts due to B0 inhomogeneity. Limited detail of in vivo B0 conditions apparent in various population groups impede the development of optimal cardiac B0 shim methods. Goal(s): To validate our recently-published high-resolution B0 simulation approach of B0 conditions in the human heart based on structural CT images. Approach: Validation was achieved through direct comparison of B0 conditions computationally derived from structural CT images, vs. in vivo B0 maps obtained experimentally on the same five subjects. Results: Excellent agreement occurred between simulated and in vivo B0 maps, with an average spatial correlation of 0.91. Impact: The validated cardiac B0 simulation from readily-available structural CT images enables characterization of B0 conditions in populations with wide-spread demographics of age, sex, height, weight and the development of advanced B0 shimming methods to improve diagnostic accuracy in cardiovascular MRI.