2007 Volume 6 Issue 4 Pages 235-240
We investigated the effects of fast recovery (FR) to increase the sensitivity of fluorine-19 (19F) fast spin echo (FSE) in mapping 5-fluorouracil (5-FU) and its metabolites. We added an additional 90° pulse (which flips back longitudinal magnetization at the end of the sequence) to the chemical shift selective 19F FSE pulse sequence. In 5-FU solution, FR remarkably improved the signal-to-noise (S/N) ratio of 19F 5-FU images, having higher effects with shorter repetition time and smaller echo train numbers. In animal studies, FR produced a conspicuous increase in 19F signals in the urinary bladder. FR effects for 19F signals in the liver were smaller than those in other organs but still substantial. Utilization of FR in 19F FSE images promises more sensitive observation of 19F metabolite maps of 5-FU and other 19F-containing compounds that have relatively long relaxation times.
