Handbook of Biomedical Optics

170 Handbook of Biomedical Optics

into the tissue, typically over one eective scattering length

(0.5–1 mm, depending on the wavelength). Nevertheless, the

light in the thin layer at the tissue surface is not completely ran-

domized. In this thin region, the details of the elastic scattering

process are preserved. e total signal reected from tissue can

be divided into two parts: single backscattering from the upper-

most tissue structures such as cell nuclei and a background of

diusely scattered light. To analyze the single scattering com-

ponent of the reected light, the diusive background must be

removed. is can be achieved either by modeling using diuse

reectance spectroscopy (Zonios et al. 1999, Georgakoudi et al.

2001) or by ...