Advances in optical coherence tomography for dermatology

TL;DR

This paper reviews recent advances in optical coherence tomography (OCT), especially full-field and line-field OCT, highlighting their high resolution, deeper imaging capabilities, and potential for in vivo skin imaging in dermatology.

Contribution

It introduces recent developments in FF-OCT and LF-OCT, emphasizing their improved imaging depth, speed, and suitability for dermatological applications.

Findings

LF-OCT offers deeper tissue imaging than FF-OCT.

LF-OCT enables faster B-scan imaging for in vivo use.

Both OCT methods achieve near cellular resolution in skin imaging.

Abstract

This paper reports on advances in optical coherence tomography (OCT) for application in dermatology. Full-field OCT is a particular approach of OCT based on white-light interference microscopy. FF-OCT produces en face tomographic images by arithmetic combination of interferometric images acquired with an area camera and by illuminating the whole field of view with low-coherence light. The major interest of FF-OCT lies in its high imaging spatial resolution ($\sim$ 1.0 $\mu$m) in both lateral and axial directions, using a simple and robust experimental arrangement. Line-field OCT (LF-OCT) is a recent evolution of FF-OCT with line illumination and line detection using a broadband spatially coherent light source and a line-scan camera in an interference microscope. LF-OCT and FF-OCT are similar in terms of spatial resolution. LF-OCT has a significant advantage over FF-OCT in terms of imaging penetration depth due to the confocal gate achieved by line illumination and detection. B-scan imaging using FF-OCT requires the acquisition of a stack of en face images, which usually prevents in vivo applications. B-scan imaging using LF-OCT can be considerably faster due to the possibility of using a spatially coherent light source with much higher brightness along with a high-speed line camera. Applied in the field of dermatology, the LF-OCT images reveal a comprehensive morphological mapping of skin tissues in vivo at a cellular level similar to histological images.