Light scattering spectroscopy (LSS) is a spectroscopic technique typically used to evaluate morphological changes in epithelial cells in order to study mucosal tissue and detect early cancer and

precancer Carcinoma ''in situ'' (CIS) is a group of abnormal cells. While they are a form of neoplasm, there is disagreement over whether CIS should be classified as cancer. This controversy also depends on the exact CIS in question (i.e. cervical, skin, bre ...

. Light scattering spectroscopy relies upon elastic scattering of

photons A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they alway ...

reflected from the

epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

. Most of the signal is generated by light scattering from small intracellular structures, but larger intracellular structures, such as nuclei, also scatter light, with their relative contribution increasing in the backscatter direction. As changes in the morphology of epithelial cells are hallmarks of pre-cancer and early cancer, LSS can be used for early cancer diagnosis. In addition to photons backscattering from epithelial cells, a major portion of photons penetrates the epithelium, reaching optically turbid connective tissue where they are scattered multiple times and partially absorbed by hemoglobin. As a result, it is not possible to measure single backscattering events directly in human tissue, with polarization gating and spatial gating well-suited for endoscopy applications.

History

Lev T. Perelman, principal scientist at MIT, and

Vadim Backman Vadim Backman is an American biomedical engineer and the Sachs Family Professor of biomedical engineering at the Robert R. McCormick School of Engineering and Applied Science at Northwestern University. He is also a Professor of Medicine (Hematolo ...

, graduate student in Harvard- MIT Health Sciences and Technology program introduced LSS in 1998.

Applications

Light scattering spectroscopy has been applied for detection of precancer in many organs including esophagus, colon, urinary bladder, oral cavity, cervix, pancreatic cyst, stomach, skin, and bile duct.

References

{{Branches of Spectroscopy Spectroscopy Imaging