Confocal microscopy from the bench to the bedside.

摘要

Confocal microscopy is a powerful tool for performing high-resolution imaging in optically thick biologic tissue using the process of optical sectioning. The basic principle is shown in Figure 1, where light emerging from a fiber is focused by an objective lens into the tissue. Scattered light originating from the in-focus plane converges back into the fiber, whereas light from the out-of-focus planes is inefficiently collected. Confocal microscopy is sensitive to fluorescence, unlike optical coherence tomography, another method being developed for performing optical sectioning and, thus, can provide greater image contrast and observe mucosal function. Conventional confocal microscopes are large laboratory instruments that use complex, high numerical aperture objectives to achieve subcellular resolution. Previously, the primary challenge that has limited the in vivo use of confocal microscopy was the ability to reduce the optics and the scanning mechanism to an endoscope-compatible size. In this issue of Gastrointestinal Endoscopy, Polgase et al describe the use of a novel, confocal imaging prototype that uses 488-nm illumination to produce fluorescence images from normal esophagus, antrum, duodenum, ileum, colon, and rectum in vivo. These images reveal sharp cellular and subcellular details that provide a striking comparison with corresponding histology.