title: Statistical and economical efficiency in assessment of liver regeneration using defined sample size and selection in combination with a fully automated image analysis system.
abstract: Quantification of liver regeneration is frequently based on determining the 5-bromo-2-deoxyuridine labeling index (BrdU-LI). The quantitative result is influenced by preanalytical, analytical, and postanalytical variables such as the region of interest (ROI). We aimed to present our newly developed and validated automatic computer-based image analysis system (AnalySIS-Macro), and to standardize the selection and sample size of ROIs. Images from BrdU-labeled and immunohistochemically stained liver sections were analyzed conventionally and with the newly developed AnalySIS-Macro and used for validation of the system. Automatic quantification correlated well with the manual counting result (r=0.9976). Validation of our AnalySIS-Macro revealed its high sensitivity (>90%) and specificity. The BrdU-LI ranged from 11% to 57% within the same liver (32.96 +/- 11.94%), reflecting the highly variable spatial distribution of hepatocyte proliferation. At least 2000 hepatocytes (10 images at 200x magnification) per lobe were required as sample size for achieving a representative BrdU-LI. Furthermore, the number of pericentral areas should be equal to that of periportal areas. The combination of our AnalySIS-Macro with rules for the selection and size of ROIs represents an accurate, sensitive, specific, and efficient diagnostic tool for the determination of the BrdU-LI and the spatial distribution of proliferating hepatocytes.
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University Hospital Essen, 45122 Essen, Germany.
authors.forename: Meihong
authors.initials: M
authors.lastname: Deng
authors.forename: Robert
authors.initials: R
authors.lastname: Kleinert
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
authors.forename: Qing
authors.initials: Q
authors.lastname: He
authors.forename: Fotima
authors.initials: F
authors.lastname: Madrahimova
authors.forename: Olaf
authors.initials: O
authors.lastname: Dirsch
authors.forename: Uta
authors.initials: U
authors.lastname: Dahmen
mesh_terms: D000818:Animals; D001331:Automation; D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D007091:Image Processing, Computer-Assisted / Q000191:economics / Q000379:methods*; D008115:Liver Regeneration; D008297:Male; D015588:Observer Variation; D051381:Rats; D011917:Rats, Inbred Lew; D015203:Reproducibility of Results; D018401:Sample Size; D013194:Staining and Labeling; D013997:Time Factors
chemical_list: D001973:Bromodeoxyuridine