"Excisional biopsy is one of the gold standards for the diagnosis of cancer, but is a sampling procedure. If the biopsy is taken in a normal region of tissue and misses the cancer, the biopsy result is negative although the patient still has cancer," notes Fujimoto, whose team is one of a number of research groupsincluding at Johns Hopkins University; the University of California, Irvine; Case Western University; and Massachusetts General Hospitalthat are actively pursuing the development of smaller, faster endoscopic OCT systems.
Endoscopic OCT requires miniature optical catheters or probesjust a few millimeters in diameterthat can scan an optical beam in two dimensions to generate high-resolution 3-D data sets. Scanning the beam in one transverse direction generates an image in a cross-sectional plane, whereas scanning the beam in two directions generates a stack of cross-sectional imagesthat is, a 3-D (or volumetric), image.
"This device development is one of the major technical challenges in endoscopic OCT because probes must be small enough so that they can be introduced into the body, but still be able to scan an optical beam at high speeds," Fujimoto says. "Increasing imaging speeds has also been an important research objective because high-resolution volumetric imaging requires very large amounts of data in order to cover appreciable regions of tissue, so rapid image acquisition rates are a powerful advantage."
The optical catheter developed by the MIT researchers and their collaborators uses a piezoelectric transducer, a miniature device that bends in response to electrical current, allowing a laser-light emitting optical fiber to be rapidly scanned over the area to be imaged.
So far, the devicewhich must be further reduced in size, Fujimoto notes, before it can be deployed with the standard endoscopes now us
|Contact: Angela Stark|
Optical Society of America