D. Tokarz, R. Cisek, Ahmad Golaraei, S. Krouglov, R. Navab, Carolyn J. Niu, S. Sakashita, K. Yasufuku, M. Tsao, S. Asa, V. Barzda, B. Wilson
{"title":"Tumor tissue characterization using polarization-sensitive second harmonic generation microscopy","authors":"D. Tokarz, R. Cisek, Ahmad Golaraei, S. Krouglov, R. Navab, Carolyn J. Niu, S. Sakashita, K. Yasufuku, M. Tsao, S. Asa, V. Barzda, B. Wilson","doi":"10.1117/12.2180969","DOIUrl":"https://doi.org/10.1117/12.2180969","url":null,"abstract":"Changes in the ultrastructure of collagen in various tumor and non-tumor human tissues including lung, pancreas and thyroid were investigated ex vivo by a polarization-sensitive second harmonic generation (SHG) microscopy technique referred to as polarization-in, polarization-out (PIPO) SHG. This involves measuring the orientation of the linear polarization of outgoing SHG as a function of the linear polarization orientation of incident laser radiation. From the PIPO SHG data, the second-order nonlinear optical susceptibility tensor component ratio, χ(2) ZZZ’/χ(2) ZXX’, for each pixel of the SHG image was obtained and presented as color-coded maps. Further, the orientation of collagen fibers in the tissue was deduced. Since the χ(2) ZZZ’/χ(2) ZXX’ values represent the organization of collagen in the tissue, theses maps revealed areas of altered collagen structure (not simply concentration) within tissue sections. Statistically-significant differences in χ(2) ZZZ’/χ(2) ZXX’ were found between tumor and non-tumor tissues, which varied from organ to organ. Hence, PIPO SHG microscopy could potentially be used to aid pathologists in diagnosing cancer. Additionally, PIPO SHG microscopy could aid in characterizing the structure of collagen in other collagen-related biological processes such as wound repair.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126975175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Borys Mogilevych, L. dos Santos, J. L. Rangel, K. Grancianinov, Mariane P J Sousa, A. Martin
{"title":"Analysis of the in vivo confocal Raman spectral variability in human skin","authors":"Borys Mogilevych, L. dos Santos, J. L. Rangel, K. Grancianinov, Mariane P J Sousa, A. Martin","doi":"10.1117/12.2181030","DOIUrl":"https://doi.org/10.1117/12.2181030","url":null,"abstract":"Biochemical composition of the skin changes in each layer and, therefore, the skin spectral profile vary with the depth. In this work, in vivo Confocal Raman spectroscopy studies were performed at different skin regions and depth profile (from the surface down to 10 μm) of the stratum corneum, to verify the variability and reproducibility of the intra- and interindividual Raman data. The Raman spectra were collected from seven healthy female study participants using a confocal Raman system from Rivers Diagnostic, with 785 nm excitation line and a CCD detector. Measurements were performed in the volar forearm region, at three different points at different depth, with the step of 2 μm. For each depth point, three spectra were acquired. Data analysis included the descriptive statistics (mean, standard deviation and residual) and Pearson's correlation coefficient calculation. Our results show that inter-individual variability is higher than intraindividual variability, and variability inside the SC is higher than on the skin surface. In all these cases we obtained r values, higher than 0.94, which correspond to high correlation between Raman spectra. It reinforces the possibility of the data reproducibility and direct comparison of in vivo results obtained with different study participants of the same age group and phototype.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116675142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Full-field optical coherence tomography for tissue imaging","authors":"A. Dubois","doi":"10.1117/12.2186645","DOIUrl":"https://doi.org/10.1117/12.2186645","url":null,"abstract":"Full-field optical coherence tomography (FF-OCT) is a biomedical imaging technique based on white-light interference microscopy. FF-OCT produces tomographic images by arithmetic combination of interferometric images acquired with an area camera and by illuminating the whole field to be imaged with low-coherence light. The major interest for FFOCT lies in its high imaging resolution in both transverse and axial directions using a simple and robust experimental arrangement. This paper provides an overview of the principle of FF-OCT. The system characteristics are reported in details, including the detection sensitivity and spatial resolution. Several of the challenges, advantages and drawbacks of the technique are discussed and compared with other optical imaging techniques such as conventional OCT and confocal microscopy. Images of normal and diseased human breast tissue are presented to illustrate the potential of FF-OCT for cellular-level anatomopathological examinations without sample processing.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127403255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Morales-Delgado, I. Papadopoulos, S. Farahi, D. Psaltis, C. Moser
{"title":"Delivery of ultrashort spatially focused pulses through a multimode fiber for two photon endoscopic imaging","authors":"E. Morales-Delgado, I. Papadopoulos, S. Farahi, D. Psaltis, C. Moser","doi":"10.1117/12.2180332","DOIUrl":"https://doi.org/10.1117/12.2180332","url":null,"abstract":"Due to their high number of supported modes, multimode optical fibers carry large amount of spatio-temporal information. However, propagation of a light pulse through a multimode optical fiber suffers from spatial distortions due to superposition of the various exited modes and from time broadening due to modal dispersion. Here, we present a method based on digital phase conjugation to selectively excite specific optical fiber modes in a multimode fiber that follow similar optical paths as they travel through the fiber. In this way, they can be made to interfere constructively at the fiber output to generate an ultrashort spatially focused pulse. The excitation of a limited number of modes limits modal dispersion, allowing the transmission of an ultrashort pulse. We also show that the short spatially focused pulse can be scanned digitally without movable elements. We experimentally demonstrate that the pulse at the output of the multimode fiber generate a two-photon signal. We show delivery of a 1550 nm pulse with 500 fs duration, spatially focused to a spot size of 7 micrometers, through a 30 cm long, 200 micrometers core multimode step-index fiber. We show how this technique is applied to endoscopic two-photon imaging.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130251259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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