Using nematics for the optical diagnosis of malignant tumors

This paper shows for the first time that it is possible to diagnose maligna nt tumors of various tissues of humans and animals by using a polarization- optical method based on the use of nematic crystals. It is found that the m olecules of nematic liquid crystals always orient themselves homeotropicall y on malignant tumors, and that their orientation is close to planar on ben ign tumors and on healthy tissue. The difference in orientation is explaine d by the difference of the surface tension of the tissues and is a new biop hysical criterion that opens up possibilities for the objective diagnosis o f malignant tumors. (C) 1999 The Optical Society of America. [S1070-9762(99 )02206-X].