1.7-Micron Optical Coherence Tomography Angiography for Characterization of Skin Lesions–A Feasibility Study

Abstract

Optical coherence tomography (OCT) is a noninvasive diagnostic method that offers real-time visualization of the layered architecture of the skin in vivo. The 1.7-micron OCT system has been applied in cardiology, gynecology and dermatology, demonstrating an improved penetration depth in contrast to conventional 1.3-micron OCT. To further extend the capability, we developed a 1.7micron OCT/OCT angiography (OCTA) system that allows for a visualization of both morphology and microvasculature in the deeper layers of the skin. Using this imaging system, we imaged human skin with different benign lesions and described the corresponding features of both structure and vasculature. The significantly improved imaging depth and additional functional information suggest that the 1.7-micron OCTA system has great potential to advance both dermatological clinical and research settings for characterization of benign and cancerous skin lesions.

Intravascular polarization-sensitive optical coherence tomography based on polarization mode delay

“…To address this issue, the imaging range can be increased through doubling the k-clock frequency or through dual edge sampling. In addition, a swept-source laser with a longer center wavelength, such as 1.7 μm, can be utilized to further improve penetration depth 39 – 41 .…”

Measuring collagen injury depth for burn severity determination using polarization sensitive optical coherence tomography

“…In the long run, the speed and range of OCT imaging continue to increase with fundamental advances such as ultrafast laser sources 31 and circular ranging 32 , which promise to enable substantially larger-scale PS-OCT imaging in the future. Another potential limitation of OCT is its penetration depth; while 1-1.5mm is enough to assess the dermis at many anatomical locations, OCT sources at longer wavelengths (1.7 micron) could provide even deeper characterization of skin 33 .…”

Advances in Endoscopic Photoacoustic Imaging

“…In addition, diagnostic accuracy is limited by sample number and size [92][93][94]. To address the limitations of a conventional colonoscopy, endoscopic US, OCT, NIRF, and multiphoton have been applied in the GI tract to visualize the layered architecture and microvasculature, detect early stage disease, and assess treatment response with exogenous optical contrast agents, which represents a significant step toward noninvasive comprehensive characterization of GI disease [3,38,[95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111]. However, one of the key parameters, SO 2 saturation, is still lacking.…”