High resolution imaging of acne lesion development and scarring in human facial skin using OCT-based microangiography

Abstract

Background and Objective Acne is a common skin disease that often leads to scarring. Collagen and other tissue damage from the inflammation of acne give rise to permanent skin texture and microvascular changes. In this study, we demonstrate the capabilities of optical coherence tomography based microangiography in detecting high-resolution, three-dimensional structural and microvascular features of in vivo human facial skin during acne lesion initiation and scar development. Materials and Methods A real time swept source optical coherence tomography system is used in this study to acquire volumetric images of human skin. The system operates on a central wavelength of 1310 nm with an A-line rate of 100 kHz, and with an extended imaging range (~12 mm in air). The system uses a handheld imaging probe to image acne lesion on a facial skin of a volunteer. We utilize optical microangiography (OMAG) technique to evaluate the changes in microvasculature and tissue structure. Results Thanks to the high sensitivity of OMAG, we are able to image microvasculature up to capillary level and visualize the remodeled vessels around the acne lesion. Moreover, vascular density change derived from OMAG measurement is provided as an alternative biomarker for the assessment of human skin diseases. In contrast to other techniques like histology or microscopy, our technique made it possible to image 3D tissue structure and microvasculature up to 1.5 mm depth in vivo without the need of exogenous contrast agents. Conclusion The presented results are promising to facilitate clinical trials aiming to treat acne lesion scarring, as well as other prevalent skin diseases, by detecting cutaneous blood flow and structural changes within human skin in vivo.

In vivo tissue injury mapping using optical coherence tomography based methods

“…To visualize the transition from acne lesion initiation to scarring stages, longitudinal changes in a selected acne lesion on human facial skin is monitored using a swept-source OCT system (Thorlabs Inc.) descripted in [13]. Briefly in this system, the source is able to sweep the lasing wavelength across a broad spectral range near 1310 nm at a fixed repetition rate of 100 kHz with 15 μm axial resolution in tissue.…”

“…This takes approximately 20 seconds covering 3mm × 3mm area when the imaging rate is set at 100 fps. Details of this protocol can be found in [13]. These imaging protocols are repeated multiple times at multiple connected locations to create a final mosaic image to effectively increase the field of view.…”

“…During the last few years, OMAG technique has been intensively used to study the microvasculature of a variety of biological tissues in vivo . For example, OMAG has been recently used to investigate the vascular abnormalities in human facial skin with acne vulgaris [13]. It has also been used to study mouse cerebral microvasculature [14, 15], and to image capillary morphology inside a healthy and an inflamed human skin in vivo (16, 17).…”

Combined multi-modal photoacoustic tomography, optical coherence tomography (OCT) and OCT angiography system with an articulated probe for in vivo human skin structure and vasculature imaging

“…The functional extension of OCT angiography contrasts specifically blood flow against static tissue based on signal decorrelation without the need of contrast agents, thereby providing microvascular details with high contrast in strongly scattering tissue that are not visible with standard OCT [12]. OCT angiography has been applied to image facial or palmar human skin [13][14][15]. But even with focus field extension using Bessel beams or contrast enhancement algorithms to reduce the residual static artifacts, the effective angiographic imaging depth is well below 2 mm.…”

Automated segmentation and enhancement of optical coherence tomography-acquired images of rodent brain

“…OMAG has been used to study the microvasculature of a variety of tissues in vivo , including healthy and diseased human skin (Baran et al 2015a), human retina (Zhang et al 2015), and mouse cerebral microvasculature (Baran et al 2015c; Baran and Wang 2016). Moreover, OCT-based tissue injury mapping (TIM) depicts the changes in tissue properties by characterizing the attenuation of light inside the tissue (Baran et al 2015b).…”