Elastic scattering spectroscopy of coagulated brain tissues

The goal of this study was to differentiate the parts of lamb brain according to elastic scattering spectroscopy and detect the optical alterations due to coagulation. Cells and tissues are not uniform and have complex structures and shapes. They can be referred to as scattering particles. The process of scattering depends on the light wavelength and on the scattering medium properties; especially on the size and the density of the medium. When elastic scattering spectroscopy (ESS) is employed, the morphological alterations of tissues can be detected using spectral measurements of the elastic scattered light over a wide range of wavelengths. In this study firstly, the slopes of ESS spectra were used to differentiate the parts of lamb brains (brainstem, cerebellum, gray matter, white matter) in vitro in the range of 450 - 750 nm. Secondly, tissues were coagulated at different temperatures (45, 60, and 80 °C) and ESS spectra were taken from native and coagulated tissues. It was observed that as the coagulation temperature increased, the slope of the elastic scattering spectra decreased. Thus, optical properties of tissues were changed with respect to the change in nuclear to cytoplasmic ratio due to the water loss. Results showed that the slopes of ESS spectra in the visible range revealed valuable information about the morphological changes caused by coagulation.

[2]  S. Jacques,et al.  Optical reflectance and transmittance of tissues: principles and applications , 1990 .

[3]  G. Weiss,et al.  Model for photon migration in turbid biological media. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[4]  Sharon Thomsen,et al.  Spectroscopic diagnosis of cervical intraepithelial neoplasia (CIN) in vivo using laser‐induced fluorescence spectra at multiple excitation wavlengths , 1996, Lasers in surgery and medicine.

[5]  S. Lakhani,et al.  Diagnosis of breast cancer using elastic-scattering spectroscopy: preliminary clinical results. , 2000, Journal of biomedical optics.

[6]  I. Yaroslavsky,et al.  Optical properties of selected native and coagulated human brain tissues in vitro in the visible and near infrared spectral range. , 2002, Physics in medicine and biology.

[7]  E Gratton,et al.  Quantitative determination of the absorption spectra of chromophores in strongly scattering media: a light-emitting-diode based technique. , 1994, Applied optics.

[8]  R. Richards-Kortum,et al.  Optical spectroscopy for detection of neoplasia. , 2002, Current opinion in chemical biology.

[9]  J. Mourant,et al.  Particle size analysis of turbid media with a single optical fiber in contact with the medium to deliver and detect white light. , 2001, Applied optics.

[10]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .

[11]  M S Patterson,et al.  Influence of layered tissue architecture on estimates of tissue optical properties obtained from spatially resolved diffuse reflectometry. , 1998, Applied optics.

[12]  M. Hartmann,et al.  Light scattering by small particles. Von H. C. VANDE HULST. New York: Dover Publications, Inc. 1981. Paperback, 470 S., 103 Abb. und 46 Tab., US $ 7.50 , 1984 .

[13]  V Blazek,et al.  Optical properties of human brain tissue, meninges, and brain tumors in the spectral range of 200 to 900 nm. , 1987, Neurosurgery.

[14]  Michael B. Wallace,et al.  Observation of periodic fine structure in reflectance from biological tissue: A new technique for measuring nuclear size distribution , 1998 .

[15]  Changhuei Yang,et al.  Cellular organization and substructure measured using angle-resolved low-coherence interferometry. , 2002, Biophysical journal.

[16]  A. Wax,et al.  Determining nuclear morphology using an improved angle-resolved low coherence interferometry system. , 2003, Optics express.

[17]  H. A. Ferwerda,et al.  Scattering and absorption of turbid materials determined from reflection measurements. 1: theory. , 1983, Applied optics.

[18]  Michael S. Feld,et al.  Imaging human epithelial properties with polarized light-scattering spectroscopy , 2001, Nature Medicine.

[19]  E. Wolf,et al.  Principles of Optics (7th Ed) , 1999 .

[20]  W. Steen.  Absorption and Scattering of Light by Small Particles , 1999 .

[21]  Michael S. Feld,et al.  Measuring cellular structure at submicrometer scale with light scattering spectroscopy , 2001 .

[22]  J. Mourant,et al.  Ultraviolet and visible spectroscopies for tissue diagnostics: fluorescence spectroscopy and elastic-scattering spectroscopy. , 1997, Physics in medicine and biology.

[23]  R Richards-Kortum,et al.  Cervical fluorescence of normal women , 1999, Lasers in surgery and medicine.

[24]  Ashleyj . Welch,et al.  Optical-Thermal Response of Laser-Irradiated Tissue , 1995 .