Miniature microscope can improve disease detection, diagnosis and treatment

Miniature microscope can improve disease detection, diagnosis and treatment

November 3, 2009

New imaging technology using one of the world's smallest flexible microscopes enables physicians to look--at the cellular level--at living, moving tissue in the lungs and gastrointestinal tract so they can make a rapid diagnosis or carefully select tissue for biopsy.

With the probe-based, confocal, laser-endomicroscopy system known as Cellvizio®, which is used through a standard endoscope or bronchoscope, University of Chicago physicians can examine tissue in the gastrointestinal tract or look deep into the lungs to examine and assess early stages of disease.

With magnification 500 to 1,000 times that of a standard scope and 10 to 50 times that of a magnifying scope, the Cellvizio system, one of about 40 in the United States, can help doctors distinguish between normal and cancerous tissue without taking samples. If they do need samples, the probe helps them collect exactly the tissue they need for a biopsy rather than extracting multiple samples from the general vicinity of suspected disease.

"Until now, if we found suspicious tissue during a diagnostic procedure, we had to take out tissue almost randomly and send it to a laboratory for analysis," said Irving Waxman, MD, professor of medicine and surgery at the University of Chicago, the first center in Illinois to use the system. "This meant that cancerous tissue could be missed."

"With this scope," said Waxman, "we can pinpoint abnormal tissue during the initial diagnostic exam, remove it, and then go back to be certain that we got what we needed."

The tiny microscope, produced by Mauna Kea Technologies of Paris, France, (known as Cellvizio in the U.S.) is approved by the Food & Drug Administration for use in the gastrointestinal tract and lungs. It consists of a laser light system coupled with a miniprobe made of tens of thousands of individual optical fibers capped by microlenses. The scope is only 2.5 mm in diameter, small enough to pass through accessory channels on most standard GI or pulmonary scopes. Specialists worldwide have used the device for more than 3,000 procedures to date.

The tiny flexible device is inserted through a channel in a standard scope. The tip is placed on the tissue to be examined. It sends back 12 high-resolution video images per second. By adjusting the focus, the probe can also provide clear, detailed images of tissue slightly beneath the surface.

Recent studies have demonstrated the value of the technology in multiple areas. "We currently use it to identify precancerous areas in Barrett's esophagus (the major risk factor for esophageal cancer) for improved detection and targeting of minimally invasive endoscopic therapy," said Vani Konda, MD, instructor of medicine at the University of Chicago. "The technology can also be applied in the colon, bile duct and pancreas to try to differentiate cancer from inflammatory (benign) disorders."

The microscope does a good job of catching early cancers and diagnosing them immediately, without having to wait for a pathology report, according to Mauna Kea Chief Executive Sacha Loiseau. "It's especially useful in getting into tiny bile ducts," he adds.

"Detailed microscopic images of the esophagus or the bile ducts can help us reduce the risk of biopsy-related complications," said Waxman. "By identifying in vivo the area of interest we can move right then to follow with a therapeutic application."

"The tiny miniprobe can also be inserted through the bronchoscope and extended well into the lungs, even to the smaller branches of the bronchial tree," said pulmonologist Kyle Hogarth, MD, FCCP, assistant professor of medicine and director of bronchoscopy at the University of Chicago. "Better visualization could help us perform fewer, more-targeted biopsies," he said. "It lets us examine and sample tissues that were previously inaccessible without surgery."