Pill-sized device eases gut imaging

Physicians may soon have a new and easy way to screen the esophagus, or gut, for a precancerous condition caused by chronic exposure to stomach acid, according to an American study.

Researchers at the Wellman Centre for Photomedicine at Massachusetts General Hospital (MGH) have developed a capsule sized imaging device that creates detailed, microscopic images of the esophageal (gut) wall. It 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,” says Gary Tearney, pathologist of the Wellman Centre of the MGH and study co-author, the journal Nature Medicine.

“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,” adds Tearney, according to an MGH statement.

The system developed by Tearney and his colleagues involves a capsule containing optical frequency domain imaging (OFDI) 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. The OFDI images are taken throughout the capsule’s transit down and up the esophagus.

The researchers tested the system in a group of unsedated participants – some are known to have Barrett’s esophagus and others were healthy volunteers.

The physicians operating the system were able to image the entire esophagus in less than a minute, and a procedure involving four passes – two down the esophagus and two up – could be completed in around six minutes. A typical endoscopic examination requires that the patient stay in the endoscopy unit for approximately 90 minutes.

Reference:
Michalina J Gora, Jenny S Sauk, Robert W Carruth, Kevin A Gallagher, Melissa J Suter, Norman S Nishioka, Lauren E Kava, Mireille Rosenberg, Brett E Bouma, Guillermo J Tearney. Tethered capsule endomicroscopy enables less invasive imaging of gastrointestinal tract microstructure. Nature Medicine, 2013; DOI: 10.1038/nm.3052