Line-Field Confocal Optical Coherence Tomography (LC-OCT) for Skin Imaging in Dermatology

Abstract

Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive optical imaging technique based on a combination of the principles of optical coherence tomography and reflectance confocal microscopy with line-field illumination, which can generate cell-resolved images of the skin in vivo. This article reports on the LC-OCT technique and its application in dermatology. The principle of the technique is described, and the latest technological innovations are presented. The technology has been miniaturized to fit within an ergonomic handheld probe, allowing for the easy access of any skin area on the body. The performance of the LC-OCT device in terms of resolution, field of view, and acquisition speed is reported. The use of LC-OCT in dermatology for the non-invasive detection, characterization, and therapeutic follow-up of various skin pathologies is discussed. Benign and malignant melanocytic lesions, non-melanocytic skin tumors, such as basal cell carcinoma, squamous cell carcinoma and actinic keratosis, and inflammatory and infectious skin conditions are considered. Dedicated deep learning algorithms have been developed for assisting in the analysis of LC-OCT images of skin lesions.

Line‐field confocal optical coherence tomography: Characteristic hints for the diagnosis of scarring alopecia due to lupus erythematodes: A preliminary study

“…In recent years, LC‐OCT has emerged as an innovative noninvasive imaging method that combines the advantages of both methods due to its higher resolution than OCT and increased penetration depth compared to RCM. 25 , 26 It has already proven its value in the diagnosis of numerous tumorous and inflammatory dermatoses. Rudnicka et al.…”

Effects of refractive index mismatch between sample and immersion medium in line-field confocal optical coherence tomography

“…We will now establish an explicit expression of the signal attenuation by simplifying the expression of function c(z). Typical values of the experimental parameters in LC-OCT are k 0 = 750 nm, Dk = 200 nm, NA = 0.5 and n im = 1.40 [1][2][3][4][5]. Considering a sample with n = 1.45 yields Dz foc % 10 lm (Eq.…”

“…LC-OCT has been designed so far for imaging of skin tissues [1,5]. The superficial skin layer (stratum corneum) has a refractive index in the near infrared around n = 1.54, and a thickness of 10-30 lm.…”

“…Line-field confocal optical coherence tomography (LC-OCT) is a recent imaging technique based on low-coherence interference microscopy [1][2][3][4]. LC-OCT uses line illumination with broadband spatially coherent light and detection with a line camera to acquire cross-sectional images of semi-transparent samples, including skin tissues [5][6][7][8][9][10][11][12][13]. The focus is dynamically adjusted during the scan of the sample depth, allowing the use of a microscope objective to image with high lateral resolution.…”

An Update on Non-Invasive Skin Imaging Techniques in Actinic Keratosis—A Narrative Review

“…One of the recently introduced methods in the assessment of skin tumors is line-field optical coherence tomography (LC-OCT). It is a new imaging modality that is based on a combination of optical coherence tomography and reflectance confocal microscopy with line-field illumination, which presents cell-resolved images of the skin in vivo [94]. Its application in dermatooncology, including AK, has recently been published [95] and allows AKs to be differentiated from SCC [96].…”