Abstract
A detailed comparison of six multivariate algorithms is presented to analyze and generate Raman microscopic images that consist of a large number of individual spectra. This includes the segmentation algorithms for hierarchical cluster analysis, fuzzy C-means cluster analysis, and k-means cluster analysis and the spectral unmixing techniques for principal component analysis and vertex component analysis (VCA). All algorithms are reviewed and compared. Furthermore, comparisons are made to the new approach N-FINDR. In contrast to the related VCA approach, the used implementation of N-FINDR searches for the original input spectrum from the non-dimension reduced input matrix and sets it as the endmember signature. The algorithms were applied to hyperspectral data from a Raman image of a single cell. This data set was acquired by collecting individual spectra in a raster pattern using a 0.5-μm step size via a commercial Raman microspectrometer. The results were also compared with a fluorescence staining of the cell including its mitochondrial distribution. The ability of each algorithm to extract chemical and spatial information of subcellular components in the cell is discussed together with advantages and disadvantages.
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Krafft C, Dietzek B, Popp J (2009) Raman and CARS microspectroscopy of cells and tissues. Analyst 134:1046–1057
Nan X, Potma E, Xie X (2006) Nonperturbative chemical imaging of organelle transport in living cells with coherent anti-stokes Raman scattering microscopy. Biophys J 91:728–735
Freudiger CW, Min W, Saar BG, Lu S, Holtom GR, He C, Tsai JC, Kang JX, Xie XS (2008) Label-free biomedical imaging with high sensitivity by stimulated Raman scattering microscopy. Science 322:1857–1861
Diem M (1993) Introduction to modern vibrational spectroscopy. Wiley, Hoboken
Krafft C, Steiner G, Beleites C, Salzer R (2009) Disease recognition by infrared and Raman spectroscopy. J Biophotonics 2:13–28
Bocklitz T, Putsche M, Stüber C, Käs J, Niendorf A, Rösch P, Popp J (2009) A comprehensive study of classification methods for medical diagnosis. J Raman Spectrosc 40:1759–1765
Hedegaard M, Krafft C, Ditzel HJ, Johansen LE, Hassing S, Popp J (2009) Discriminating isogenic cancer cells and identifying altered unsaturated fatty acid content as associated with metastasis status, using k-means clustering and PLS-DA of Raman maps. Anal Chem 82:2797–2802
Miljkovic M, Chernenko T, Romeo MJ, Bird B, Matthäus C, Diem M (2010) Label-free imaging of human cells: algorithms for image reconstruction of Raman hyperspectral datasets. Analyst 135:2002–2013
Matthäus C, Chernenko T, Quintero L, Milane L, Kale A, Amiji M, Torchilin V, Diem M (2008) Raman microscopic imaging of cells and applications monitoring the uptake of drug delivery systems. Proc SPIE 6991, 699106. doi:10.1117/12.800385
Chernenko T, Matthäus C, Milane L, Quintero L, Amiji M, Diem M (2009) Label-free Raman spectral imaging of intracellular delivery and degradation of polymeric nanoparticle systems. ACS Nano 3:3552–3559
Krafft C, Alipour Diderhoshan M, Recknagel P, Miljkovic M, Bauer M, Popp J (2011) Crisp and soft multivariate methods visualize individual cell nuclei in Raman images of liver tissue sections. Vib Spectrosc 55:90–100
Nascimento JMP, Bioucas-Dias JM (2005) Vertex component analysis: a fast algorithm to unmix hyperspectral data. IEEE Trans Geosci Remote Sens 43:898–910
Keshava N (2003) A survey of spectral unmixing algorithms. Lincoln Lab J 14:55–73. www.ll.mit.edu/publications/journal/pdf/vol14_no1/14_1survey.pdf
Winter ME (1999) N-FINDR: an algorithm for fast autonomous spectral end-member determination in hyperspectral data. Proc SPIE 3753:266–275. doi:10.1117/12.366289
Berman M, Phatak A, Lagerstrom R, Wood BR (2009) ICE: a new method for the multivariate curve resolution of hyperspectral images. J Chemometrics 23:101–116
Matthäus C, Chernenko T, Newmark JA, Warner CM, Diem M (2007) Label-Free detection of mitochondrial distribution in cells by nonresonant Raman microspectroscopy. Biophys J 93:668–673
Ward JH (1963) Hierarchical grouping to optimize objective function. J Am Statistical Assoc 58:236–244
MacQueen J (1967) Some methods for classification and analysis of multivariate observations. Proc Fifth Berkeley Symp Math Stat Probab 1:287–297. http://www-m9.ma.tum.de/foswiki/pub/WS2010/CombOptSem/kMeans.pdf
Bezdek JC (1981) Pattern recognition with fuzzy objective function algorithms. Kluwer, Norwell
Bezdek JC, Ehrlich R, Full W (1984) FCM: the fuzzy c-means clustering algorithm. Comp Geosci 10:191–203
Lasch P, Haensch W, Naumann D, Diem M (2004) Cluster analysis of colorectal adenocarcinoma imaging data: a FT-IR microspectroscopic study. Biochim Biophys Acta 1688:176–186
Pearson K (1901) On lines and planes of closest fit to systems of points in space. Philosophical Magazine Series 6 2(11):559–572
Nascimento JMP, Bioucas-Dias JM (2003) Vertex component analysis: a fast algorithm to extract endmembers spectra from hyperspectral data. Proc First IbPRIA, ser LNCS 2652:626–635. doi:10.1007/978-3-540-44871-6_73
Matthäus C, Kale A, Chernenko T, Torchilin V, Diem M (2008) New ways of imaging uptake and intracellular fate of liposomal drug carrier systems inside individual cells, based on Raman microscopy. Mol Pharm 5:287–293
Awa K, Okumura T, Shinzawa H, Otsuka M, Ozaki Y (2008) Self-modeling curve resolution (SMCR) analysis of near-infrared (NIR) imaging data of pharmaceutical tablets. Anal Chim Acta 619:81–86
Lopes MB, Wolff J, Bioucas-Dias JM, Figueiredo MAT (2010) Near-infrared hyperspectral unmixing based on a minimum volume criterion for fast and accurate chemometric characterization of counterfeit tablets. Anal Chem 82:1462–1469
Vaden TD, de Boer TS, Simons JP, Snoek LC, Suhai S, Paisz B (2008) Vibrational spectroscopy and conformational structure of protonated polyalanine peptides isolated in the gas phase. J Phys Chem A 112:4608–4616
Zhuang W, Hayashi T, Mukamel S (2009) Coherent multidimensional vibrational spectroscopy of biomolecules: concepts, simulations, and challenges. Angew Chem Int Ed Engl 48:3750–3781
Caspers PJ, Lucassen GW, Puppels GJ (2003) Combined in vivo confocal Raman spectroscopy and confocal microscopy of human skin. Biophys J 85:572–580
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CK and JP acknowledge financial support of the European Union via the Europäischer Fonds für Regionale Entwicklung (EFRE) and the “Thüringer Ministerium für Bildung, Wissenschaft und Kultur” (Project: B714-07037).
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Dedicated to Professor Akira Imamura on the occasion of his 77th birthday and published as part of the Imamura Festschrift Issue.
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Hedegaard, M., Matthäus, C., Hassing, S. et al. Spectral unmixing and clustering algorithms for assessment of single cells by Raman microscopic imaging. Theor Chem Acc 130, 1249–1260 (2011). https://doi.org/10.1007/s00214-011-0957-1
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DOI: https://doi.org/10.1007/s00214-011-0957-1