Complex refractive index of normal and malignant human colorectal tissue in the visible and near-infrared.
A multi-wavelength prism coupling refractometer is utilized to measure the angular reflectance of freshly excised human intestinal tissue specimens. Based on reflectance data, the real and imaginary part of the refractive index is calculated via Fresnel analysis for three visible (blue, green, red) and two near-infrared (963 nm and 1551 nm) wavelengths. Averaged values of the complex refractive index and corresponding Cauchy dispersion fits are given for the mucosa, submucosa and serosa layers of the colorectal wall at the normal state. The refractive constants of tumorous and normal mucosa are then cross-compared for the indicative cases of one patient diagnosed with a benign polyp and three patients diagnosed with adenocarcinomas of different phenotype. Significant index contrast exists between the normal and diseased states, indicating the potential use of refractive index as a marker of colorectal dysplasia.
Laboratory of Electronic Devices and Materials, Department of Electronic Engineering, Technological Educational Institute of Athens, Athens, 12210, Greece.
Panagiotis
P
Giannios
Laboratory of Electronic Devices and Materials, Department of Electronic Engineering, Technological Educational Institute of Athens, Athens, 12210, Greece.
Spyridon
S
Koutsoumpos
First Department of Propaedeutic Surgery, Hippocration Hospital, Athens Medical School, National and Kapodistrian University of Athens, Athens, 11525, Greece.
Konstantinos G
KG
Toutouzas
First Department of Propaedeutic Surgery, Hippocration Hospital, Athens Medical School, National and Kapodistrian University of Athens, Athens, 11525, Greece.
Maria
M
Matiatou
First Department of Propaedeutic Surgery, Hippocration Hospital, Athens Medical School, National and Kapodistrian University of Athens, Athens, 11525, Greece.
George C
GC
Zografos
Laboratory of Electronic Devices and Materials, Department of Electronic Engineering, Technological Educational Institute of Athens, Athens, 12210, Greece.
Konstantinos
K
Moutzouris
D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D012031:Refractometry; D019265:Spectroscopy, Near-Infrared
colorectal cancer; refractive index; tissue optics