[MR imaging oral contrast agent mixed with milk for the small intestine]

To investigate the usefulness of MRI oral contrast media in enhancing the entire small intestine using FerriSeltz (Otsuka Pharmaceuticals, Tokyo), which contains ferric ammonium citrate, we compared the relaxation times and taste of 7 kinds of contrast media (Milk FerriSeltz A-G) that contain FerriSeltz dissolved in 7 different ratios of distilled water-milk. We also compared the homogeneity of the contrast enhancement of the entire small intestine on T1-weighted images between Milk FerriSeltz-F (a mixture of distilled water and milk at a ratio of 1:5 with FerriSeltz), which was found to be the best contrast medium based on the relaxation times and taste, and Milk FerriSeltz-A (distilled water with FerriSeltz) in 10 healthy volunteers. The T1 and T2 values decreased as the proportion of milk increased. The T1 and T2 values of Milk FerriSeltz-F were 71 msec and 28 msec, markedly shorter than those of Milk FerriSeltz-A (340 msec and 290 msec). T1-weighted images taken with Milk FerriSeltz-F showed more homogeneous enhancement of the entire small intestine than those taken with Milk FerriSeltz-A. There were no adverse effects in these 10 volunteers. Milk FerriSeltz-F seems to be an ideal oral contrast medium for enhancement of the entire small intestine.