Patent ID: 6236208
Filing Date: 2001-05-22
Classification: G01R

Abstract:
A magnetic resonance imaging apparatus which includes a gradient coil system for generating a magnetic gradient field in an imaging volume of the apparatus, the gradient coil system comprising:a first coil for generating a first part of the gradient field, anda second coil for generating a second part of the gradient field,wherein the second coil is proportioned in such a manner that in the second part of the gradient field generated by this coil the ratio R=(max.sub.dev)/(max.sub.lin) is larger than 1, where max.sub.lin is the maximum value of the linear component of the second part of the gradient field in the imaging volume and max.sub.dev is the maximum value of the deviation of the linear component of the second part of the gradient field in the imaging volume,wherein the apparatus further comprises switching means for driving the first and the second coil, mutually independently or not, as desired, andwherein the apparatus also includes a first and a second drive amplifier for driving the first coil and the second coil, respectively.