A novel double-surface coil approach to phosphorus-31 spectroscopy: a study of hemispheric brain injury in the rat

An arrangement of two surface coils was devised to allow phosphorus-31 (31P) NMR spectroscopy of a localized hemispheric brain injury model in the rat. Two elliptical (8 X 12 mm) surface coils are placed parallel to each other (3 mm apart) over each side of the rat head. Spectra are collected from either the normal or the injured side of the head using the appropriate surface coil. A passive detuning method was used to eliminate unwanted coil-coil interactions. 31P imaging results with the two coils on phantoms show excellent isolation (6% signal overlap) between the two coils. The two-coil setup was then used to follow a time course of injury from the hemispheric injury model.