Described herein is a magnet system for use in imaging a volume that includes a main magnet and at least one magnet coil assembly positioned between the main magnet and the imaging volume. A gradient coil assembly including an inner primary gradient coil alone or with the addition of an outer secondary gradient coil may also exist between the main magnet and imaging volume. The magnet coil assembly may then be positioned between the inner primary gradient coil and the imaging volume, between the inner primary gradient coil and outer secondary gradient coil, or in both positions. Also described herein is an MRI system incorporating the magnet system with additional magnet coil assemblies, and the process for improving the homogeneity of a magnet system using the additional magnet coil assemblies.