Patent ID: 7009476

Claim:
A vertical field type MRI apparatus for forming magnetic resonance images, including: at least one first field generating superconducting coil system for producing a substantially homogeneous magnetic field in an imaging volume of the apparatus, which coil system includes: a round outer coil arranged in an outer coil plane; and a round supplementary coil arranged within the outer coil, wherein the energizing of the outer coil and of the supplementary coil generates magnetic fields of opposite direction, wherein the supplementary coil is located in the outer coil plane, and wherein the ratio D a /D o of the diameter D a of the supplementary coil to the diameter D o of the outer coil is between 0.7 and 0.9; and a second field generating superconducting coil system for producing the substantially homogeneous magnetic field in the imaging volume of the apparatus, which second coil system includes: a second round outer coil arranged in a second outer coil plane and having a diameter that is larger than the diameter of the first outer coil, and a second round supplementary coil arranged within the second outer coil and in the second outer coil plane, wherein the energizing of the second outer coil and of the second supplementary coil generates magnetic fields of opposite direction.