Capsule endoscopy (CE) displays the small bowel's entire length (as long as 25 feet) as the intestine's involuntary muscles push this "camera pill" forward. CE heralds an important step forward in the diagnosis of small bowel disorders, demonstrating more abnormalities than standard small bowel imaging techniques. But its greater promise may lie in conjunction with computed tomography (CT). CE does a good job of indicating the presence of abnormalities, but does not tell their location.
The video capsule - the size of a large vitamin pill - is swallowed by a patient after an eight-hour fast. Eliminated about eight hours later, the capsule transmits a continuous stream of digital images to a small data recorder worn around the patient's waist. The physician then downloads the data and analyzes the images at a workstation.
"As the camera tumbles through the intestine, you don't know exactly where the mass is located. CT, by contrast, provides a very good global view of the body, and specialized parameters can be employed to localize lesions," said lead author Amy K. Hara, M.D., diagnostic radiologist at Mayo Clinic in Scottsdale, Ariz.
Among those who may benefit from CE are people with Crohn's disease, a form of inflammatory bowel disease that occurs most often in the lower portion of the small intestine and is marked by diarrhea, abdominal pain and bleeding.
Unlike standard endoscopy, CE-also known as wireless endoscopy-can examine the entire small intestine. Endoscopy, which uses a fiberoptic scope, reaches only the upper and very lower portion of the small intestine.
CE also demonstrated more tumors, ulcers, vascular malformations and other small bowel abnormalities than ingested barium exams or CT, the current diagnostic standards for small intestine disorders.
The Mayo study reviewed data on the first 52 patients to undergo CE at the clinic following a barium study or CT for unexplained gastrointestinal bleeding, inflammatory bowel disease or chronic abdominal pain. Forty patients received a barium study and CE. Of those, CE helped radiologists detect abnormalities in 22 patients (55 percent), while barium studies yielded abnormal results in only 1 patient (3 percent). Nineteen patients underwent CT examination as well as CE. Of those, CE helped radiologists detect abnormalities in 12 patients (63 percent), while CT yielded abnormal results in 4 patients (21 percent).
"We wanted to see what we were missing or not missing with standard radiology techniques," said Dr. Hara, principal author of the study. "The information we are gaining from CE will allow us to improve our use of CT for better diagnoses and determine when to pair the two technologies."
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"Small Bowel Findings: Comparison of Capsule Endoscopy, Barium Studies, and CT." Collaborating with Dr. Hara on this paper were Jonathan A. Leighton, M.D., Virender K. Sharma, M.D., and David E. Fleischer, M.D.