Pill-sized imaging system offers detailed images of esophageal lining

An imaging system enclosed in a pill-sized capsule may soon provide a method to screen patients for Barrett’s esophagus, according to a report published online Jan. 13 in Nature Medicine. Researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital in Boston said the system, which creates detailed, microscopic images of the esophageal wall, has several advantages over traditional endoscopy.

"This system gives us a convenient way to screen for Barrett's that doesn't require patient sedation, a specialized setting and equipment or a physician who has been trained in endoscopy," Gary Tearney, MD, PhD, said in a press release. "By showing the three-dimensional, microscopic structure of the esophageal lining, it reveals much more detail than can be seen with even high-resolution endoscopy."

Tearney and colleagues developed the capsule containing a technology called optical frequency domain imaging (OFDI). This technology uses a rapidly rotating laser tip emitting a beam of near-infrared light and sensors that record light reflected back from the esophageal lining.  An attached string-like tether connects the capsule to an imaging console and also allows the physician or other professional to control the system.

The capsule is designed to be swallowed by a patient and carried down the esophagus by normal contraction of the surrounding muscles. Once it’s reached the entrance to the stomach, the capsule is pulled back up by the tether, and OFDI images are taken throughout the process.

Tearney and colleagues tested the system in 13 unsedated participants, six of whom had Barrett’s esophagus and seven who served as healthy volunteers. Images were able to clearly distinguish cellular changes that signified Barrett’s esophagus, reported the researchers.

“Other methods we have tried can compress the esophageal lining, making it difficult to obtain accurate, three-dimensional pictures,” said Tearney. “The capsule device provides additional key diagnostic information by making it possible to see the surface structure in greater detail."

Another advantage of the new device over endoscopy is the short procedure time. An endoscopy exam can take approximately 90 minutes; the authors reported the capsule system can image the entire esophagus in less than a minute, with a procedure involving four passes completed in approximately six minutes. Study participants who had previously undergone endoscopy indicated they preferred the new procedure.