[High concentration ferric ammonium citrate (FAC) solution as a negative bowel contrast agent]

Various concentrations of ferric ammonium citrate (FAC) solution were scanned with conventional SE, Turbo SE (TSE) and STIR sequences on a 0.5-T MR unit. High-concentration FAC solution showed significant signal loss on T2-weighted images. Signal loss was more prominent on heavily T2-weighted images with longer TR/TE using the TSE sequence. T1-weighted images did not show significant signal loss even with high-concentration solution. On STIR images, remarkable signal loss occurred at twice the concentration that had a T1 value similar to fat. We concluded that high-concentration FAC solution may employ as a negative contrast agent in upper abdominal MR imaging.