Improvement of tissue analysis and classification using optical coherence tomography combined with Raman spectroscopy

Abstract

Optical coherence tomography (OCT) provides signi¯cant advantages of high resolution (approaching the histopathology level) real-time imaging of tissues without use of contrast agents. Based on these advantages, the microstructural features of tumors can be visualized and detected intra-operatively: However, it is still not clinically accepted for tumor margin delineation due to poor speci¯city and accuracy. In contrast, Raman spectroscopy (RS) can obtain tissue information at the molecular level, but does not provide real-time imaging capability. Therefore, combining OCT and RS could provide synergy. To this end, we present a tissue analysis and classi¯cation method using both the slope of OCT intensity signal vs depth and the principle components from the RS spectrum as the indicators for tissue characterization. The goal of this study was to understand prediction accuracy of OCT and combined OCT/RS method for classi¯cation of optically similar tissues and organs. Our pilot experiments were performed on mouse kidneys, livers, and small intestines (SIs). The prediction accuracy with¯ve-fold cross validation of the method has been evaluated by the support vector machine (SVM) method. The results demonstrate that tissue characterization based on the OCT/RS method was superior compared to using OCT structural information alone. This combined OCT/RS method k Corresponding authors.

Raman Microscopy: Progress in Research on Cancer Cell Sensing

“…Single-point Raman spectra were acquired to specifically characterize the biochemical fingerprint of ambiguous structures within the OCT tissue image [ 51 ]. Pilot experiments by Liu et al demonstrated successful proof-of-concept tumor margin prediction in near-clinical situations by the OCT-Raman system and potential as a novel optical biopsy technique for cancer detection [ 56 ].…”

Reagent- and separation-free measurements of urine creatinine concentration using stamping surface enhanced Raman scattering (S-SERS)

“…Compared to traditional analytical methods, Raman and SERS methods offer several advantages. They require no reagents or separation, are non-invasive, are capable of qualitative and quantitative measurements, and provide molecular structure information [14][15][16][17][18][19][20][21]. In particular, SERS is a highly-sensitive Raman spectroscopic technique where Raman scattering is enhanced primarily by near-field electromagnetic enhancement due to localized surface plasmon resonance (LSPR) [22].…”

Constrained regularization for noninvasive glucose sensing using Raman spectroscopy

“…2,7,14 Raman spectroscopy provides detailed quantitative information about sample composition, and is thus a promising technique for study of biological systems. [15][16][17][18][19][20][21] Glucose is a convenient analyte to study because its concentration can be conveniently altered and monitored in human volunteers. As shown below, numerical simulations and in vivo data collected noninvasively from the forearm of volunteers demonstrate that CR, when used with appropriate constraints, provides a calibration with signi¯cantly improved prediction accuracy compared to PLS.…”