In vitro measurement conditions for optical coherence tomography (OCT)

Abstract

Conclusion. Tissue marking with soot-covered fine needles enables the optical coherence tomography (OCT) scanning plane to be localized within the histological specimen to an accuracy of ∼50 µm. Tissue water content is an especially important parameter for in vitro measurements. Dehydration tends to produce an increase in surface reflections and a reduction in imaging depth. Objectives. The aim of this in vitro study was to evaluate parameters relevant to the visualization and conservation process to allow optimal images to be generated for later differentiation between healthy and degenerated tissue in vivo. Materials and methods. Various methods of marking samples were applied in vitro to achieve accurate overlaps of the OCT scanning plane and the corresponding section of the histological specimen. The influence of temperature and tissue water content was investigated using both porcine and human tissue. Samples were marked using fine needles, ablation craters generated by laser application, and colour markers introduced into the tissue. Results. It was demonstrated that the water content of tissue exerts a direct influence on OCT imaging, whereas above 15°C temperature had no effect on image quality. With regard to the marking of samples, the best results were obtained using sooted fine needles.

• Optical coherence tomography (OCT)
• histological specimen