Milk does a body good for CT exams

Milk is just as good as a contrast agent for GI tract imaging with CT as the barium agent now used, according to research presented at the 2006 RSNA meeting.

Milk achieves bowel distension and enhancement similar to that seen with VoLumen, the commonly used contrast agent from E-Z-EM, for a fraction of the price, according to Dr. Lisa R. Shah-Patel, a radiology resident at St. Luke's-Roosevelt Hospital in New York. VoLumen costs $18 per patient. Whole milk costs $1.39. And patients like it.

"We found that patients are more willing to drink milk because it is part of their daily lives and they know what to expect," she said.

When CT of the GI tract is performed, typically to assess abdominal pain, a negative oral contrast agent is usually used to distinguish between the bowel cavity and soft tissue. Barium-based VoLumen is often administered with intravenous contrast. Milk, however, does a good job in place of VoLumen, filling the intestinal cavity and making it appear dark, while the intravenous contrast enhancement makes the intestinal wall appear bright. The dark intestinal cavity contrasting with the bright intestinal wall makes evidence of disease on the bowel wall more visible.

Shah-Patel and colleagues studied 179 adult patients undergoing CT with oral and intravenous contrast for abdominal discomfort to compare cost-effectiveness and patient tolerance for whole milk versus VoLumen. Sixty-two patients received VoLumen, and 117 received milk. About 40% of VoLumen patients reported cramps, diarrhea, or nausea, while only about 23% of the milk patients reported such responses.

"We hope that substituting milk for other contrast agents will reduce the number of people who refuse imaging tests because they do not want to drink the oral contrast, especially children," Shah-Patel said.