Optical coherence tomography (OCT) is an advanced optical imaging technology for imaging material based on their optical scattering properties. OCT provides high-resolution 2D (en face or cross-sectional) and 3D images from the surface and subsurface tissue microstructures within a few mm depth. The first article on OCT was published in 1991 by D. Huang et. al. . More than 15000 articles have been published since 1991 on different applications of OCT. However, the technique has so far entered the clinical routine only within ophthalmology and cardiovascular imaging in which the majority of the articles have been published . OCT is a capable technology with great potentials for further translational research and implementation in additional clinical fields. One potential application of OCT is within cancer detection intraoperatively or post operatively for providing an on-site fast diagnosis. In this study, OCT’s ability to differentiate histology and pathology for application in tissue identification, pathological diagnosis and cancer staging was investigated.
Material and Method:
The technology uses near infrared or infrared light for imaging tissue structures that havedifferent optical scattering properties. The technique is based on low coherence interferometryand measures the backscattered light from the tissue. The scanning dimensions and resolutions are dependent on the type of the OCT system. In this study a TELESTO IITM system (Thorlabs, Inc., NJ, USA) was used. The maximum lateral and axial resolution of the system were 13 and 5.5 μm, respectively. A total of eleven patients undergoing brain, thyroid and parathyroid surgery were included in the study.
Figure 1 shows a 3D scan of the fingertip taken by the described OCT system as an example. The skin layers (epidermis and dermis) including the fingerprint and a sweat gland (the spiral structure) are visible. Various tissue type specimens involved in thyroid and parathyroid surgeries and brain tumor surgery were evaluated.