MR method for determining the magnetic field inhomogeneity in an examination zone, and MR apparatus for carrying out the method
 The invention relates to an MR method for determining the frequency map in an examination zone as well as to an appropriate sequence in which the nuclear magnetization is read in conjunction with the read gradient of varying direction. Subsequent to an excitation of the nuclear magnetization, a plurality of MR echo signals are acquired. From the sub-images acquired with different echo times on the one hand the frequency map can be derived whereas on the other hand these sub-images can be combined so as to form an MR overall image of higher spatial resolution. The invention also relates to a device for carrying out this method. 
U.S. Philips Corporation
G
G01R
inventional
Volker
Rasche