17 Vibrational Microspectroscopy for Analysis of Atherosclerotic Arteries
531
cholesterol crystals, hemoglobin (hb), calcium crystals (hydroxyapatite), ascorbic
acid, α-tocopherol and β-carotene. The capabilities of Raman spectroscopy allow for
the classification of the state of the aorta into such categories as non-atherosclerotic,
atherosclerotic, calcified, non-calcified and vulnerable.
Analysis of results of the IR and Raman images would be impossible without
the use of chemometric techniques. In order to give better insight into the composition of the plaque, different exploratory techniques, as well as different models of classification and regression, can be used. When utilized along with Raman
studies, the most successful chemometric methods are principal component analysis (PCA), independent component analysis (ICA), hierarchical cluster analysis
(hCA), K-means clustering (KmC), the second linear least squers-minimalization
(LSm) model and the unsupervised spectral unmixing algorithm vertex component
analysis (vCA). For IR images, principal component analysis (PCA) and hierarchical cluster analysis (hCA) are mainly used. It is also noteworthy that the application of advanced multivariate techniques such as Partial Least Squares—discriminant Analysis (PLS-dA) or mahalonobis distance—Linear discriminant Analysis
(md-LdA) is used to analyze IR results.
vibrational images correlate well with histopathology, which confirms the potential of these techniques for biochemical and structural discrimination of plaque
components. We believe that the future developments in these label-free techniques
will provide unique high-content image of morphological and most importantly
biochemical composition of the atherosclerotic plaque that may have diagnostic
prognostic and therapeutic significance.
Acknowledgements this study was supported by European union from the resources of the
European Regional development Fund under the Innovative Economy Programme (grant coordinated by JCEt-uJ, No PoIg.01.01.02-00-069/09). the tissues for histological and vibrational
microscopy examples of atherosclerotic plaque analysis presented in this chapter were taken from
ApoE/LdLR
−/−
mice [128].
References
1. Wrobel tP, marzec Km, majzner K, Kochan K, Bartus m, Chlopicki S, Baranska m (2012)
Analyst 137:4135–4139
2. Peres mB, Silveira L, Zangaro RA, Pacheco mtt, Pasqualucci CA (2011) Lasers med Sci
26:645–655
3. Krafft C, Sergo v (2006) Spectroscopy 20:195–218
4. Wang L, mizaikoff B (2008) Anal Bioanal Chem 391:1641–1654
5. Kazarian Sg, Chan KL (2006) BBA 1758:858–867
6. Bhargava R, Fernandez dC, hewitt Sm, Levin I (2006) BBA 1758:830–845
7. Walsh, m. J, Kajdacsy-Balla, A, holton, S. E, Bhargava, R. Vibrational Spectroscopy2012, 60,
23–28
8. Reddy R, davis B, Carney PS, Bhargava R (2011) IEEE Proceedings—International Symposium on Biomedical Imaging, 2011. doi:10.1109/ISBI.2011.5872511
9. Chew SF, Wood BR, Kanaan C, Browning J, macgregor d, davis Id, Cebon J, tait Bd,
mcNaughton d (2007) tiss Ant 69(1), 252–258
531
cholesterol crystals, hemoglobin (hb), calcium crystals (hydroxyapatite), ascorbic
acid, α-tocopherol and β-carotene. The capabilities of Raman spectroscopy allow for
the classification of the state of the aorta into such categories as non-atherosclerotic,
atherosclerotic, calcified, non-calcified and vulnerable.
Analysis of results of the IR and Raman images would be impossible without
the use of chemometric techniques. In order to give better insight into the composition of the plaque, different exploratory techniques, as well as different models of classification and regression, can be used. When utilized along with Raman
studies, the most successful chemometric methods are principal component analysis (PCA), independent component analysis (ICA), hierarchical cluster analysis
(hCA), K-means clustering (KmC), the second linear least squers-minimalization
(LSm) model and the unsupervised spectral unmixing algorithm vertex component
analysis (vCA). For IR images, principal component analysis (PCA) and hierarchical cluster analysis (hCA) are mainly used. It is also noteworthy that the application of advanced multivariate techniques such as Partial Least Squares—discriminant Analysis (PLS-dA) or mahalonobis distance—Linear discriminant Analysis
(md-LdA) is used to analyze IR results.
vibrational images correlate well with histopathology, which confirms the potential of these techniques for biochemical and structural discrimination of plaque
components. We believe that the future developments in these label-free techniques
will provide unique high-content image of morphological and most importantly
biochemical composition of the atherosclerotic plaque that may have diagnostic
prognostic and therapeutic significance.
Acknowledgements this study was supported by European union from the resources of the
European Regional development Fund under the Innovative Economy Programme (grant coordinated by JCEt-uJ, No PoIg.01.01.02-00-069/09). the tissues for histological and vibrational
microscopy examples of atherosclerotic plaque analysis presented in this chapter were taken from
ApoE/LdLR
−/−
mice [128].
References
1. Wrobel tP, marzec Km, majzner K, Kochan K, Bartus m, Chlopicki S, Baranska m (2012)
Analyst 137:4135–4139
2. Peres mB, Silveira L, Zangaro RA, Pacheco mtt, Pasqualucci CA (2011) Lasers med Sci
26:645–655
3. Krafft C, Sergo v (2006) Spectroscopy 20:195–218
4. Wang L, mizaikoff B (2008) Anal Bioanal Chem 391:1641–1654
5. Kazarian Sg, Chan KL (2006) BBA 1758:858–867
6. Bhargava R, Fernandez dC, hewitt Sm, Levin I (2006) BBA 1758:830–845
7. Walsh, m. J, Kajdacsy-Balla, A, holton, S. E, Bhargava, R. Vibrational Spectroscopy2012, 60,
23–28
8. Reddy R, davis B, Carney PS, Bhargava R (2011) IEEE Proceedings—International Symposium on Biomedical Imaging, 2011. doi:10.1109/ISBI.2011.5872511
9. Chew SF, Wood BR, Kanaan C, Browning J, macgregor d, davis Id, Cebon J, tait Bd,
mcNaughton d (2007) tiss Ant 69(1), 252–258