title: In vivo measurement of the shape of the tissue-refractive-index correlation function and its application to detection of colorectal field carcinogenesis.
abstract: Polarization-gated spectroscopy is an established method to depth-selectively interrogate the structural properties of biological tissue. We employ this method in vivo in the azoxymethane (AOM)-treated rat model to monitor the morphological changes that occur in the field of a tumor during early carcinogenesis. The results demonstrate a statistically significant change in the shape of the refractive-index correlation function for AOM-treated rats versus saline-treated controls. Since refractive index is linearly proportional to mass density, these refractive-index changes can be directly linked to alterations in the spatial distribution patterns of macromolecular density. Furthermore, we found that alterations in the shape of the refractive-index correlation function shape were an indicator of both present and future risk of tumor development. These results suggest that noninvasive measurement of the shape of the refractive-index correlation function could be a promising marker of early cancer development.
authors.affiliation: Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60218, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Gomes
authors.forename: Sarah
authors.initials: S
authors.lastname: Ruderman
authors.forename: Mart
authors.initials: M
authors.lastname: DelaCruz
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Wali
authors.forename: Hemant K
authors.initials: HK
authors.lastname: Roy
authors.forename: Vadim
authors.initials: V
authors.lastname: Backman
mesh_terms: D000465:Algorithms; D000818:Animals; D001397:Azoxymethane; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000737:chemistry* / Q000175:diagnosis; D003113:Colonoscopy; D008297:Male; D009010:Monte Carlo Method; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000737:chemistry / Q000175:diagnosis; D051381:Rats; D011916:Rats, Inbred F344; D012031:Refractometry / Q000295:instrumentation / Q000379:methods*; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D001397:Azoxymethane