Imaging of ex vivo nonmelanoma skin cancers in the optical and terahertz spectral regions Optical and Terahertz skin cancers imaging

Abstract

We tested the hypothesis that polarization sensitive optical and terahertz imaging may be combined for accurate nonmelanoma skin cancer (NMSC) delineation. Nine NMSC specimens were imaged. 513 μm and 440 nm wavelengths were used for terahertz and optical imaging, respectively. Histopathology was processed for evaluation. Terahertz reflectance of NMSC was quantified. Our results demonstrate that cross-polarized terahertz images correctly identified location of the tumours, whereas cross-polarized and polarization difference optical images accurately presented morphological features. Cross-polarized terahertz images exhibited lower reflectivity values in cancer as compared to normal tissue. Combination of optical and terahertz imaging shows promise for intraoperative delineation of NMSC.

Optical feedback effects on terahertz quantum cascade lasers: modelling and applications

“…[9][10][11] Due to the inherently low penetration depth of THz radiation in hydrated biological tissue, biological and particularly superficial skin imaging are applications to which THz frequency imaging is well suited. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] As such, imaging of superficial skin employing THz QCLs in confocal reflection-mode system geometry is an ideal application for the technique. 31,32 Laser feedback interferometry (LFI) with THz QCLs exploits the interferometric nature of optical feedback in a THz QCL to create a homodyning THz transceiver operating in confocal configuration.…”

High-contrast coherent terahertz imaging of porcine tissue via swept-frequency feedback interferometry

“…These differing THz properties offer a new means of understanding the structure and function of specialised tissue, as well as the potential for discriminating normal from pathological material [5][6][7]. Of particular interest are THz biomedical images, which have the potential to highlight different information than those acquired at other frequencies, thereby providing an augmented picture of biological structures [8]. One important class of these THz images are functional images of relative water saturation, made possible due to the strong absorption of THz radiation by liquid water [9].…”

THz QCL self-mixing interferometry for biomedical applications

“…The potential of skin tissue imaging at terahertz wavelengths for the discrimination between healthy and pathological tissue has been explored in a number of studies. [1][2][3][4][5][6] Imaging skin in different frequency bands provides complementary information about skin. Terahertz (THz) frequency radiation is particularly well suited for this largely functional, biological imaging due to its sensitivity to water content, as a consequence of high absorption of THz radiation in water.…”