Colorectal Cancer
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2005; 11(16): 2413-2419
Published online Apr 28, 2005. doi: 10.3748/wjg.v11.i16.2413
Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques
Hua-Jiang Wei, Da Xing, Jian-Jun Lu, Huai-Min Gu, Guo-Yong Wu, Ying Jin
Hua-Jiang Wei, Da Xing, Huai-Min Gu, Ying Jin, Institute of Laser Life Science, South China Normal University, Guangzhou 510631, Guangdong Province, China
Jian-Jun Lu, Guo-Yong Wu, Department of Surgery, the First Affiliated Hospital, Sun Yat-Sen Medical University, Guangzhou 510080, Guangdong Province, China
Author contributions: All authors contributed equally to the work.
Supported by the National Major Fundamental Research Project of China 2002CCC00400 and the Team Project of Natural Science Foundation of Guangdong Province 015012
Correspondence to: Da Xing, Institute of Laser Life Science, South China Normal University, Guangzhou 510631, Guangdong Province, China. xingda@hsut.scnu.edu.cn
Telephone: +86-20-85210089 Fax: +86-20-85216052
Received: June 8, 2004
Revised: June 9, 2004
Accepted: August 21, 2004
Published online: April 28, 2005
Abstract

AIM: The purpose of the present study is to compare the optical properties of normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion in vitro at 476.5, 488, 496.5, 514.5 and 532 nm. We believe these differences in optical properties should help differential diagnosis of human colon tissues by using optical methods.

METHODS: In vitro optical properties were investigated for four kinds of tissues: normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion. Tissue samples were taken from 13 human colons (13 adenomatous, 13 normal). From the normal human colons a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion), and from the adenomatous human bladders a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion). The measurements were performed using a double-integrating-sphere setup and the optical properties were assessed from these measurements using the adding-doubling method that was considered reliable.

RESULTS: The results of measurement showed that there were significant differences in the absorption coefficients and scattering coefficients between normal and adenomatous human colon mucosa/submucosa at the same wavelength, and there were also significant differences in the two optical parameters between both colon muscle layer/chorion at the same wavelength. And there were large differences in the anisotropy factors between both colon mucosa/submucosa at the same wavelength, there were also large differences in the anisotropy factors between both colon muscle layer/chorion at the same wavelength. There were large differences in the value ranges of the absorption coefficients, scattering coefficients and anisotropy factors between both colon mucosa/submucosa, and there were also large differences in these value ranges between both colon muscle layer/chorion. There are the same orders of magnitude in the absorption coefficients for four kinds of colon tissues. The scattering coefficients of these tissues exceed the absorption coefficients by at least two orders of magnitude.

CONCLUSION: There were large differences in the three optical parameters between normal and adenomatous human colon mucosa/submucosa at the same laser wavelength, and there were also large differences in these parameters between both colon muscle layer/chorion at the same laser wavelength. Large differences in optical parameters indicate that there were large differences in compositions and structures between both colon mucosa/submucosa, and between both colon muscle layer/chorion. Optical parameters for four kinds of colon tissues are wavelength dependent, and these differences would be useful and helpful in clinical applications of laser and tumors photodynamic therapy (PDT).

Keywords: Optical properties; Laser; Normal and adenomatous human colon tissues; Integrating sphere