Proton-decoupled 19F spectroscopy of 5-FU catabolites in human liver.

An RF network and a dual-tuned surface coil are described for obtaining proton-decoupled, NOE enhanced 19F spectra from a whole body clinical imager operating at 1.5 Tesia. The network removes 19F frequency noise from the decoupler transmitter, and prevents preamplifier saturation from high-level decoupling signals. Proton decoupling of 19F spectra was optimized using a sample of urine containing 5-fluorouracil (5-FU) and its catabolite fluoro-beta-alanine (FBAL). Proton-decoupled 19F spectroscopy in vivo is demonstrated by obtaining both nonlocalized spectra and spectra localized with three-dimensional chemical shift imaging from the liver of patients undergoing 5-FU chemotherapy.