Technique for designing distributed radio frequency coils and

Abstract

A localized coil (30) is disposed in the temporally constant magnetic field of a magnetic resonance imaging system. The localized coil is designed in five steps: a static problem formulation step, a static current solution step, a discretization step, a current loop connection step, and a high frequency solution step. One radio frequency coil designed by this process to be carried on a circularly cylindrical former includes two coil sections (60, 62) disposed on opposite sides of the dielectric former. Each of the two coil sections includes a pair of inner loops (64.sub.1, 64.sub.2) disposed symmetrically relative to a z=0 plane of symmetry and a second pair of loops (68.sub.1, 68.sub.2) also disposed symmetrically about the plane of symmetry. To raise self-resonance frequency, the inner and outer loops are connected in parallel. The resonance frequency is fine-tuned with reactive elements (66.sub.1, 66.sub.2). To ensure balanced current flow between the two coil portions, the two portions are connected (78) in parallel.