Optical coherence tomography angiography offers comprehensive evaluation of skin optical clearingin vivoby quantifying optical properties and blood flow imaging simultaneously

Abstract

Abstract. Tissue optical clearing (TOC) is helpful for reducing scattering and enhancing the penetration depth of light, and shows promising potential in optimizing optical imaging performances. A mixture of fructose with PEG-400 and thiazone (FPT) is used as an optical clearing agent in mouse dorsal skin and evaluated with OCT angiography (Angio-OCT) by quantifying optical properties and blood flow imaging simultaneously. It is observed that FPT leads to an improved imaging performance for the deeper tissues. The imaging performance improvement is most likely caused by the FPT-induced dehydration of skin, and the reduction of scattering coefficient (more than ∼40.5%) and refractive-index mismatching (more than ∼25.3%) in the superficial (epidermal, dermal, and hypodermal) layers. A high correlation (up to ∼90%) between the relative changes in refractive-index mismatching and Angio-OCT signal strength is measured. The optical clearing rate is ∼5.83 × 10 −5 cm∕s. In addition, Angio-OCT demonstrates enhanced performance in imaging cutaneous hemodynamics with satisfactory spatiotemporal resolution and contrast when combined with TOC, which exhibits a powerful practical application in studying microcirculation. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Biophotonics in China

“…The depth range is extended to be over 200 mm , the lateral field of view is increased to 35 mm , and the axial resolution is improved to 0.9 μm. Angio‐OCT with enhanced contrast was developed for vasculature mapping . It is known that the lateral resolution and depth of focus in an optical imaging system are coupled and a compromise between them has to be made.…”

Control of optical transparency and infrared laser heating of costal cartilage via injection of iohexol

“…Optical clearing (OC) of biological tissues by injection of hyperosmotic agents enables to reduce the interstitial scattering of incoming laser radiation to achieve better tissue penetration for diagnostic imaging and light therapy . OC approach was successfully applied to enhance tissue visualization by different optical modalities, such as optical coherent tomography , confocal laser microscopy , fluorescent imaging including quantitative analysis , polarized photon scattering and others. While OC has a number of serious limitations in living systems associated with the rapid elution of agent and long times needed for accumulation of a proper concentration, ex vivo application is more easily controlled and can be carried out within acceptable time limits.…”

FSOCA‐induced switchable footpad skin optical clearing window for blood flow and cell imaging in vivo

“…It was well known that surgical operations were always accompanied with bleeding and changes of the normal physiological environment during process of model establishment . Recently, the rapidly developed tissue optical clearing (TOC) technique provides an alternative solution through topical application of optical clearing agents (OCAs) on the dorsal skin, which demonstrated its powerful capacity in optimizing the imaging performances, including the imaging depth, resolution, contrast and sensitivity, of various optical imaging modalities, e. g. laser speckle contrast imaging , photoacoustic microscopy , optical coherence tomography , confocal microscopy , two‐photon microscopy and flow cytometry , etc.…”