Dual-mode line-field confocal optical coherence tomography for ultrahigh-resolution vertical and horizontal section imaging of human skin in vivo

Abstract

Line-field confocal optical coherence tomography (LC-OCT) is a recently introduced technique for ultrahigh-resolution vertical section (B-scan) imaging of human skin in vivo. This work presents a new implementation of the LC-OCT technique to obtain horizontal section images (C-scans) in addition to B-scans. C-scan imaging is achieved with this dual-mode LC-OCT system using a mirror galvanometer for lateral scanning along with a piezoelectric chip for modulation of the interferometric signal. A quasi-identical spatial resolution of ⇠ 1 µm is measured for both B-scans and C-scans. The images are acquired in both modes at a rate of 10 frames per second. The horizontal field of view of the C-scans is 1.2 ⇥ 0.5 mm 2 , identical to the vertical field of view of the B-scans. The user can switch between the two modes by clicking a button. In vivo cellular-resolution imaging of human skin is demonstrated in both B-scan and C-scan modes, with the possibility to navigate within the skin tissues in real time.

Invivocharacterization of healthy human skin with a novel, non‐invasive imaging technique: line‐field confocal optical coherence tomography

“…A LC-OCT device capable of producing three-dimensional (3D) images (both in the vertical and horizontal plane), currently under development, will be used for further studies. 15 This device will help to better understand not only the 3D structure of the skin, but also the distribution patterns of blood vessels and melanin thanks to 3D modelling. Another prospect under development is the automatic DEJ detection and epidermal thickness measurement.…”

“…Some interesting clinical applications of LC‐OCT are to be expected, including diagnosis of skin cancers and inflammatory diseases; biopsy guidance; identification of tumours' surgical margins, and follow‐up of topical/systemic treatments. A LC‐OCT device capable of producing three‐dimensional (3D) images (both in the vertical and horizontal plane), currently under development, will be used for further studies 15 . This device will help to better understand not only the 3D structure of the skin, but also the distribution patterns of blood vessels and melanin thanks to 3D modelling.…”

In vivo dual-mode full-field optical coherence tomography for differentiation of types of melanocytic nevi

“…High-resolution OCT can provide an excellent imaging technique for examining cellular characteristics and quantifying the properties of skin structures including full-field OCT (FF-OCT) 17 – 19 and line-field confocal OCT (LC-OCT). 20 , 21 Although FF-OCT is a good imaging tool for en face images, the frame rate of cross-sectional imaging (B-scan) is limited by the low brightness of light sources such as halogen lamps and light emitting diodes. 18 , 19 LC-OCT is a recently introduced technique for B-scan using a line camera and a supercontinuum light source that provides high-brightness capability for OCT imaging.…”

“…An en face imaging of LC-OCT could be achieved using a mirror galvanometer for lateral scanning. 20 However, as compared to one-dimensional scanning, higher en face rates can be achieved by FF-OCT with two-dimensional (2D) parallel detection owing to the commercially available 2D image sensors with high pixel rates. 22 , 23 In addition, an FF-OCT that utilizes a 2D camera can address speckle noise because of spatial compounding.…”

In vivo imaging of Sarcoptes scabiei infestation using line‐field confocal optical coherence tomography

“…LC-OCT is based on a two-beam interference microscope with line illumination and line detection using a broadband spatially coherent light source and a line-scan camera. 8 It has three imaging modalities: en-coupe (vertical), en-face and 3D, providing a cellular resolution (1.1 9 1.3 lm).…”