Patent ID: 8085041

Claim:
An MRI apparatus comprising: a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module configured to transmit RF signals to an RF coil assembly in order to acquire MR images; and a computer having a non-transitory computer readable medium programmed to: acquire a first data point at a first location in a first phase image data set, wherein the first phase image data set is acquired at a first echo time (TE); acquire a second data point at the first location in a second phase image data set, wherein the second phase image data set is acquired at a second TE larger than the first TE such that phase wrapping does not occur between the first and second phase image data sets; acquire a third data point at the first location in a third phase image data set, wherein the third phase image data set is acquired at a third TE larger than the second TE such that phase wrapping occurs between the second and third phase image data sets; and determine a magnetic field inhomogeneity, wherein the determination of the magnetic field inhomogeneity is based on a phase of the first, second, and third data points at the first location.