Effects of static and radiofrequency magnetic field inhomogeneity in ultra-high field magnetic resonance imaging

Abstract: To characterize the severe static (B 0) and radiofrequency (B 1) magnetic field inhomogeneity in ultra-high field (≥7 T) magnetic resonance imaging, gradient echo (GE) and spin echo (SE) images of in vivo and postmortem human brains were acquired. The B 0 and B 1 inhomogeneity were experimentally mapped and/or numerically simulated, and correlated with the image artifacts. Whereas B 0 inhomogeneity affects predominantly GE images near air/tissue interfaces, B 1 inhomogeneity affects SE images more severely and shows nonintuitive patterns. Mapping of the B 0 and B 1 inhomogeneity is important in characterizing image artifacts. This will help develop better B 0 and B 1 inhomogeneity correction methods. [Copyright &y& Elsevier]