A magnetic resonance (NMR) method for fast, dynamic, spatially resolved
measurement of the temporal changes in NMR signals by means of repeated
data acquisition in individual measurements (Acq) with measuring
sequences which are sensitive to a parameter to be observed, in an NMR
apparatus with shim coils for correcting the magnetic field is
characterized in that during data acquisition of each individual
measurement (Acq) in acquisition steps (S.sub.1 . . . S.sub.n) with a
time lag, the magnetic field distribution in the NMR apparatus is
measured, technically or physiologically based changes in the magnetic
field distribution are determined therefrom in a calculation step
(S.sub.calc) as well as a change in the currents in the magnetic field
required for compensation thereof, and the dynamic changes in the
magnetic field distribution are compensated for by means of the
correspondingly changed shim currents. The inventive method permits
dynamic detection of the changes in the magnetic field distribution
through the above-mentioned factors during the measurement and
compensation thereof through corresponding re-calculation of
.DELTA.y(x,y,z) or .DELTA.B.sub.0(x,y,z) and adjustment of the shim
currents to render the magnetic field distribution for subsequent
measurements again preferably identical to the initial magnetic field
distribution.