Magnetic resonance imaging of the gastrointestinal tract: investigation of baby milk as a low cost contrast medium.

After the incidental observation of the high signal intensity of the upper GI tract in a nourished baby, we tested eight baby milks; five different fresh commercial milks, one sweetened and condensed and two lyophilized milks in order to compare their ability to contrast MR images. The images were obtained with a 1.5 T magnet whereas the "in vitro" water proton relaxation time (T1 and T2) measurements were carried out at 0.5 T. After having selected the most effective lyophilized product, that was prepared according to the manufacturer's instructions, a group of 23 adult patients, 17 males and 6 females, with a mean age of 55.8 years (range 37 to 71 years) were examined. Thirteen patients had gastric cancer and ten patients had rectal or rectosigmoid junction tumors. The most effective imaging sequence was a spin-echo T1.w. After oral intake of milk a good contrast of the stomach, with sufficient distribution in the duodenum and the very proximal bowel, was achieved in all 13 patients with gastric cancer, as was a good depiction of the rectum and the recto-sigmoid junction after enema achieved in the 10 patients with rectal cancers. Disadvantages of lyophilized milk as a contrast agent are due to partial intestinal absorption, inhomogeneous distribution and irregular intestinal passage, whereas a clear advantage of lyophilized milk as a contrast agent is its good acceptance and palatable, inexpensive and non invasive properties. Because of these limitations lyophilized milk cannot be considered a real oral contrast medium but it can enhance MR imaging of the upper abdomen, and mainly of the lower GI tract in infants and adults.