Researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital, Boston, have developed an imaging system enclosed in a capsule about the size of a multivitamin pill that creates detailed, microscopic images of the esophageal wall and has several advantages over traditional endoscopy.
This will enable physicians to screen patients for Barrett's esophagus, a precancerous condition usually caused by chronic exposure to stomach acid, they say, without patient sedation, a specialized setting and equipment, or a physician trained in endoscopy.
The system developed by Tearney and colleagues involves a capsule containing optical frequency domain imaging technology—a rapidly rotating laser tip emitting a beam of near-infrared light and sensors that record light reflected back from the esophageal lining. The capsule is attached to a string-like tether that connects to the imaging console and allows a physician or other health professional to control the system.
After the capsule is swallowed by a patient, it is carried down the esophagus by normal contraction of the surrounding muscles. When the capsule reaches the entrance to the stomach, it can be pulled back up by the tether. Images are taken throughout the capsule's transit down and up the esophagus.
An entire procedure can be completed within six minutes, as opposed to a standard endoscopy examination that requires that the patient stay in the endoscopy unit for approximately 90 minutes. The detailed microscopic images produced by the OFDI system revealed subsurface structures not easily seen with endoscopy and clearly distinguished the cellular changes that signify Barrett's esophagus.
