Probe with chest shielding for improved breast MRI.

The design and construction of an RF coil system for use in MR breast imaging is described. The two-ring, tuned Helmholtz coil, with its axis perpendicular to the chest, surrounds a single pendant breast and is coupled both internally and to the MRI transmitter/receiver by mutual induction. The addition of two symmetrical RF shields minimizes losses in the chest and significantly improves performance. Images obtained from eight healthy volunteers showed that the coil permitted imaging of breasts of diverse size with an in-plane resolution of 0.27 x 0.27 mm and a slice thickness of less than 2 mm at a field strength of 3 T as well as 1.5 T. The use of shields with surface coils in general is advocated as a method for improving signal-to-noise ratio. Magn Reson Med 43:917-920, 2000.