title: Collagen fiber angle in the submucosa of small intestine and its application in Gastroenterology.
abstract: OBJECTIVE
  To propose a simple and effective method suitable for analyzing the angle and distribution of 2-dimensional collagen fiber in larger sample of small intestine and to investigate the relationship between the angles of collagen fiber and the pressure it undergoes.
  
  
  METHODS
  A kind of 2-dimensional visible quantitative analyzing technique was described. Digital image-processing method was utilized to determine the angle of collagen fiber in parenchyma according to the changes of area analyzed and further to investigate quantitatively the distribution of collagen fiber. A series of intestinal slice's images preprocessed by polarized light were obtained with electron microscope, and they were processed to unify each pixel. The approximate angles between collagen fibers were obtained via analyzing the images and their corresponding polarized light. The relationship between the angles of collagen fiber and the pressure it undergoes were statistically summarized.
  
  
  RESULTS
  The angle of collagen fiber in intestinal tissue was obtained with the quantitative analyzing method of calculating the ratio of different pixels. For the same slice, with polarized light angle's variation, the corresponding ratio of different pixels was also changed; for slices under different pressures, the biggest ratio of collagen fiber area was changed either.
  
  
  CONCLUSIONS
  This study suggests that the application of stress on the intestinal tissue will change the angle and content of collagen fiber. The method of calculating ratios of different pixel values to estimate collagen fiber angle was practical and reliable. The quantitative analysis used in the present study allows a larger area of soft tissue to be analyzed with relatively low cost and simple equipment.
authors.affiliation: Professor and Director of Biomechanics and Medical Information Institute, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing 100022, China. yjzeng@bjpu.edu.cn
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Zeng
authors.forename: Ai-Ke
authors.initials: AK
authors.lastname: Qiao
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Yu
authors.forename: Jing-Bo
authors.initials: JB
authors.lastname: Zhao
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Liao
authors.forename: Xiao-Hu
authors.initials: XH
authors.lastname: Xu
authors.forename: Gregersen
authors.initials: G
authors.lastname: Hans
mesh_terms: D000818:Animals; D003094:Collagen / Q000032:analysis*; D005762:Gastroenterology / Q000379:methods; D007091:Image Processing, Computer-Assisted; D007413:Intestinal Mucosa / Q000648:ultrastructure*; D007421:Intestine, Small / Q000648:ultrastructure*; D008854:Microscopy, Electron; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D003094:Collagen