Novel in-vivo Confocal micro-endoscopic imaging, for screening and cancer diagnosis

Objectives: Higher quality optical images can be gained from rigid, lens based endoscopes rather than fibre bundle instruments, especially from accessible regions e.g. the aero-digestive tract. To enhance their investigative and diagnostic versatility, a research instrument has been developed, that permits both conventional endoscopic navigation and near concurrent real-time high contrast confocal micro-endoscopic imaging, from within the living patient. The aim of developing this technology is to provide instant diagnostic information such as basement membrane integrity; unlike conventional endoscopic biopsy and subsequent soft tissue histopathological analysis. Methods: The imaging system developed, was based around a lenslet-array real-time tandem scanning laser confocal microscope head (Yokogawa CSU 10 Ultraview, Perkin Elmer Life Sciences, UK), incorporating a novel flexible arm with four degrees of freedom, and “Hopkins Rod” distal endoscopic optics. The relative light efficiency of the instrument allowed configuration for both laser fluorescence and bright-field incoherent illumination imaging. Results: Cellular detail was imaged from within and below the basement membrane of both extra and intra-oral soft tissues. Confocal fluorescence modes showed tissue structure, while incoherent reflected light imaging demonstrated red blood cell movement in the subjacent tissue capillary networks. Sub-surface confocal optical sections of prepared extracted tooth material were also possible using the instrument, demonstrating both restoration structure and distribution of fluorescent labelled adhesives used in their preparation. Conclusion: Real-time endoscopic confocal and high contrast incoherent illumination microscopy is achievable for both soft and hard tissues, via a single instrument. Multi-mode remote imaging holds great research and diagnostic significance, providing the potential to acquire and review structural information in vivo, avoiding local surgical interventions which may jeopardise subsequent tissue physiology and behaviour. This work was supported by MRC Grant G9817920 & DoH Clinician Scientist Fellowship BS/DHCS/03/G121/55. The authors wish to acknowledge the technical assistance of Mr Peter Pilecki of GKT Dental Institute.