Patent ID: 6897653

Claim:
A magnetic resonance imaging method comprising the steps of: a.) generating magnetic resonance signals, having signal amplitudes and phases, by: i.) producing a uniform magnetic field, utilizing a main coil system comprising a plurality of main coils to produce said uniform magnetic field; ii.) generating RF excitation pulses, utilizing a transmission coil to generate said RF excitation pulses, such that said RF excitation pulses excite nuclear spins in an object that is to be imaged, which is residing within said uniform magnetic field; iii.) terminating said RF excitation pulses to relax said nuclear spins and thereby emit magnetic resonance signals; b.) generating temporary magnetic gradient fields, utilizing a plurality of gradient coils, by applying a temporary gradient pulse to said gradient coils to generate said temporary magnetic gradient fields; c.) superposing said temporary magnetic gradient fields on said uniform magnetic field to provide spatial encoding of the magnetic resonance signals being emitted; d.) receiving said spatially encoded magnetic resonance signals, utilizing a receiving coil; e.) correcting said signal amplitudes of said spatially encoded magnetic resonance signals, or quantities calculated from said spatially encoded signal amplitudes for deviations based on spatial non-linearities in the magnetic field strength of said temporary magnetic gradient fields, utilizing correction means, to produce corrected magnetic resonance signals, said step of correcting including calculating deviations of actual magnetic gradient field from an ideal gradient field using the geometrical shape of the gradient coils and the time profile of the temporary current pulse through the gradient coils; and f.) outputting said corrected magnetic resonance signals, utilizing output means, to form a magnetic resonance image.