Raman Chemical Imaging of Breast Tissue

Abstract

Raman chemical imaging of lipid and protein distribution in breast is performed without the use of invasive contrast agents. Instead, tissue component discrimination is based on the unique vibrational spectra intrinsic to lipids and proteins. Component discrimination is possible using ratiometric image analysis techniques. However, chemical image contrast is enhanced when techniques are employed that use the entire Raman spectrum, including peak shift analysis and multivariate image analysis. Visualization of breast tissue components is an essential step in the development of a quantitative Raman ‘optical biopsy’ technique suitable for the non-invasive detection and classification of breast cancer. A high spatial/spectral resolution Raman imaging microscope is used that employs a liquid crystal tunable filter (LCTF). The imaging performance of the Raman microscope is quantitated with the measurement of the imaging system’s contrast transfer function (CTF). A comparison between the theoretical (diffraction limited) CTF and the measured CTF establishes that the LCTF does not produce appreciable image degradation. © 1997 by John Wiley & Sons, Ltd.