Thesis defense of: Weikai XUE

Thesis defense of Weikai XUE from the Biophotonics group, at 2pm on 11 May 2022 in the auditorium of the Institut d'Optique in Palaiseau and by videoconference, on the topic: "Line-field confocal optical coherence tomography (LC-OCT) based on a Mirau interferometer for skin cancer diagnosis."

Abstract: " Skin cancers are the most common type of cancer, but if detected early, their consequences can be easily stopped. However, nowadays, diagnoses are made after a simple visual examination, possibly followed by the extraction of a sample of suspicious skin. Histological sections are then extracted from this sample by slicing it thinly then staining it. It is a time-consuming process that can, nevertheless, ascertain the presence of a tumor by observing the sections with a microscope.
Linear-field confocal optical coherence tomography (LC-OCT) is a recent optical imaging technique particularly adapted to skin imaging: it can penetrate in the skin up to ~500 µm deep, which is sufficient to observe the dermal-epidermal junction where the growth of tumors becomes dangerous. LC-OCT offers a quasi-isotropic resolution of 1 µm to resolve details at a cellular level. To do so, it takes advantage of light wave interference that makes in vivo imaging possible in a non-invasive way, without needing biopsies. Making skin imaging easy thus results in better patient follow-up.
LC-OCT systems are usually based on a Linnik interferometer using two microscope objectives. This thesis presents the development of an LC-OCT system based on a Mirau interferometer that requires only one objective in order to facilitate its integration into a portable probe and to increase the image acquisition speed. This imaging system is able to acquire vertical sections of 940 µm×350 µm (lateral x × axial z) at 17 Hz, in addition to 3D images of 940 µm × 600 µm × 350 µm (x × y × z) with an anisotropic resolution of 1.9 µm × 1.3 µm × 1.1 µm (x × y × z) and with an image quality similar to those of conventional LC-OCT systems."