1. A coil system for use with magnetic resonance imaging to form images of a region of interest, the coil system comprising: a phased array having at least two coils; means for driving each coil of said phased array at an amplitude and phase determined to focus at a target region; and an interface subsystem linking said phased array to a magnetic resonance imaging system, said magnetic resonance imaging system transmitting a substantially uniform magnetic field through said phased array to said region of interest and receiving a response to said substantially uniform magnetic field from said region of interest.