Video-rate confocal scanning laser microscope for imaging human tissues in vivo

TLDR

The microscope achieves resolution comparable to conventional histology of excised biopsies. The system uses optimized imaging parameters and custom skin‑holding fixtures and oral clamps to maintain stable contact and minimize motion. The microscope achieves video‑rate reflectance imaging of human skin and oral mucosa to depths of 350–450 µm with 0.5–1 µm lateral and 3–5 µm axial resolution, revealing normal and abnormal tissue morphology and dynamic processes.

Abstract

We have built a video-rate confocal scanning laser microscope for reflectance imaging of human skin and oral mucosa in vivo. Design and imaging parameters were determined for optimum resolution and contrast. Mechanical skin-holding fixtures and oral tissue clamps were made for stable objective lens-to-tissue contact such that gross tissue motion relative to the microscope was minimized. Confocal imaging was possible to maximum depths of 350 microm in human skin and 450 microm in oral mucosa, with measured lateral resolution of 0.5-1 microm and axial resolution (section thickness) of 3-5 microm at the 1064-nm wavelength. This resolution is comparable with that of conventional microscopy of excised biopsies (histology). Normal and abnormal tissue morphology and dynamic processes were observed.