[Elimination of bowel fluid artifact on abdominal DWI using oral contrast agent ferric ammonium citrate]

The clinical usefulness, as well as the advantages and limitations of DWI in the abdomen and pelvis, currently are under discussion. One of the limitations is the artifact from bowel fluid that may obscure lesion signals or make it difficult to detect them. The purpose of this study was to examine evidence as to whether an oral contrast agent of ferric ammonium citrate could eliminate this artifact from the bowel loop. The study consisted of a phantom study and clinical study. The density of the phantom compounded it to 1-6 times, 8 times and 12 times. We changed the density with ferric ammonium citrate to find the best density. The pulse sequence used SE-PEI and, variable parameter changed TE and b value. The signal intensity of the phantoms was visually analyzed. We took the results to an outside observer as a clinical study and confirmed the effect visually. When a signal of ferric ammonium citrate extended TE time and increased b value, it fell. As it thickened the density of phantom, it was the result that the signal deteriorated, and was good. However, an artifact from ferric ammonium citrate appeared when we exceeded 5x density. The signal of the bowel fluid artifact disappeared by having a normal person take the 4x density as in the clinical study. Elimination of bowel fluid artifact on abdominal DWI was able to suggest the possibility of taking the ferric ammonium citrate solution at 4x density.