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Singapore, Singapore

Wang J.,Optical Bioimaging Laboratory | Zheng W.,Optical Bioimaging Laboratory | Huang Z.,Optical Bioimaging Laboratory
Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Raman spectroscopy represents a label-free vibrational spectroscopic technique for studying the biochemical and biomolecular compositions of human body. Raman probe is a key component to facilitate the in vivo diagnosis by using Raman spectroscopy. We investigated a compact Raman needle probe design to be integrated into a device that can also take biopsies of solid tissues for cytological assessment, enabling concurrent Raman spectroscopic interrogation and fine needle aspiration biopsy with a single needle penetration. We described the fabrication of the Raman needle probe and its assembly with the biopsy device. Example Raman spectra of various solid tissues are given. © 2015 SPIE. Source

Bergholt M.S.,Optical Bioimaging Laboratory | Wei Z.,Optical Bioimaging Laboratory | Lin K.,Optical Bioimaging Laboratory | Ho K.Y.,National University Hospital Singapore | And 4 more authors.
Journal of Biomedical Optics

Raman spectroscopy is an optical vibrational technology capable of probing biomolecular changes of tissue associated with cancer transformation. This study aimed to characterize in vivo Raman spectroscopic properties of tissues belonging to different anatomical regions in the upper gastrointestinal (GI) tract and explore the implications for early detection of neoplastic lesions during clinical gastroscopy A novel fiber-optic Raman endoscopy technique was utilized for real-time in vivo tissue Raman measurements of normal esophageal (distal, middle, and proximal), gastric (antrum, body, and cardia) as well as cancerous esophagous and gastric tissues from 107 patients who underwent endoscopic examinations. The non-negativity-constrained least squares minimization coupled with a reference database of Raman active biochemicals (i.e., actin, histones, collagen, DNA, and triolein) was employed for semiquantitative biomolecular modeling of tissue constituents in the upper GI. A total of 1189 in vivo Raman spectra were acquired from different locations in the upper GI. The Raman spectra among the distal, middle, and proximal sites of the esophagus showed no significant interanatomical variability. The interanatomical variability of Raman spectra among normal gastric tissue (antrum, body, and cardia) was subtle compared to cancerous tissue transformation, whereas biomolecular modeling revealed significant differences between the two organs, particularly in the gastroesophageal junction associated with proteins, DNA, and lipids. Cancerous tissues can be identified across interanatomical regions with accuracies of 89.3% [sensitivity of 92.6% (162/175); specificity of 88.6% (665/751)], and of 94.7% [sensitivity of 90.9% (30/33); specificity of 93.9% (216/230)] in the gastric and esophagus, respectively, using partial least squares-discriminant analysis together with the leave-one tissue site-out, cross validation. This work demonstrates that Raman endoscopy technique has promising clinical potential for real-time, in vivo diagnosis and detection of malignancies in the upper GI at the molecular level. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). Source

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