By Brenda Tilke

Pieces of undigested food in the intestines often look like malignancies, fooling even experienced radiologists, researchers at the Medical University of South Carolina (MUSC) in Charleston reported. The group's scientific exhibit, "Dinner at the Cafe Radiologique" describes the radiographic appearance of several types of food and explains how to differentiate the food from actual pathology. In barium enema studies, phytobezoars (undigested vegetable matter) can be mistaken for adenocarcinomas. Asking patients what types of vegetables they have eaten recently can help determine whether true pathology exists. In addition, the radiographic appearance of phytobezoars usually shows that they have not attached to intestinal wall. Corn, notoriously difficult to digest, can cause filling defects in the jejunum and ilium, and may look like polyps in the colon. Grains of rice can look like parasites.

Scientific exhibits at the RSNA meeting include a range of special interest topics, such as post-mortem imaging and the radiographic appearance of food not yet digested.

Not all ingested items qualify as food. Psychiatric patients often eat unusual and sometimes harmful substances. Not only can these substances be mistaken for tumors, but they can also cause medical conditions requiring intervention. One MUSC psychiatric patient ate a bread bag tab that caused an inflammation. Ingested hair can look like gastritis and may hide underlying conditions such as ulcers. On the other hand, the radiopaque appearance of dirt can mimic that of contrast agents, adding to the diagnostic confusion.

Radiographs of patients with motility disorders may also show puzzling images. The MUSC team showed an image of undigested hamburger in a patient with achalasia; the hamburger looked almost exactly like carcinosarcoma.

Although every effort should be made to cleanse the intestine before BEs, undigested food can sometimes remain and radiologists should be aware of the radiographic appearance of a variety of food items.