Diagnostic Imaging Online
June 11, 2002

Wireless camera pill voyages through small intestine

A disposable, swallowable camera, which seemed like a novelty a few years ago, is sending images of anatomy inaccessible by conventional endoscopy. Researchers at the Cedars-Sinai Medical Center found that the remote imaging tool was able to identify the cause of gastrointestinal bleeding in most of their study patients.

Led by Dr. Simon K. Lo, director of endoscopy at Cedars-Sinai, researchers imaged 37 patients referred for bleeding of undetermined origin. Three endoscopists independently evaluated all images and provided a consensus diagnosis. Lo and colleagues presented the study at the Digestive Disease Week conference in San Francisco in May.

The wireless capsule is about the size of a large megavitamin. It holds a camera, light source, radio transmitter, and battery and transmits pictures of the small intestine to a recorder worn on the patient's belt. Six to eight hours after the patient swallows the capsule, the images are downloaded to a computer, ready for interpretation.

The camera is not directed at all, according to Lo. It makes its way down the intestinal tract by gravity and the natural propulsions of the digestive process.

"In spite of this, it is hard to recognize that the camera is actually tumbling as it takes pictures," Lo said.

Gastrointestinal blockage would be the only contraindication to the procedure, he said.

The camera located a likely source of bleeding in 59% of patients and a probable source of bleeding in 16%. Identified abnormalities included:
? 11 arteriovenous malformations
? eight small intestine ulcers
? six small intestine bleeds without definite etiology
? one bleeding small intestine tumor
? one bleeding radiation enteritis
? one site of gastric bleeding

Camera images weren't quite as bright or clean as conventional endoscopy pictures on the whole. But in some instances, the technique provided very high quality pictures.

"When compared with the pictures taken by comparable sonde enteroscopy (using an extremely long 400-cm conventional endoscope), the small intestine pictures taken by these capsules are actually of vastly superior quality," Lo said.

Perhaps the most obvious benefit to the technique is patient tolerance. Patients actually looked forward to the test, according to Lo.

While no formal studies have been done to assess the cost-effectiveness of the technique, researchers felt that it could eliminate several unnecessary procedures, including endoscopies, colonoscopies, and bleeding nuclear medicine scans.

"These indirect data are pretty good evidence that this new technology is a valuable and cost-effective tool in the management of gastrointestinal bleeding," Lo said.

For more from the Diagnostic Imaging archives:

Virtual colonoscopy prepares to enter the mainstream

Training & Education: Chest x-rays illuminate gastrointestinal cases

-- By Merlina Trevino