Analysis of second-harmonic-generation microscopy in a mouse model of ovarian carcinoma.
Second-harmonic-generation (SHG) imaging of mouse ovaries ex vivo was used to detect collagen structure changes accompanying ovarian cancer development. Dosing with 4-vinylcyclohexene diepoxide and 7,12-dimethylbenz[a]anthracene resulted in histologically confirmed cases of normal, benign abnormality, dysplasia, and carcinoma. Parameters for each SHG image were calculated using the Fourier transform matrix and gray-level co-occurrence matrix (GLCM). Cancer versus normal and cancer versus all other diagnoses showed the greatest separation using the parameters derived from power in the highest-frequency region and GLCM energy. Mixed effects models showed that these parameters were significantly different between cancer and normal (P<0.008). Images were classified with a support vector machine, using 25% of the data for training and 75% for testing. Utilizing all images with signal greater than the noise level, cancer versus not-cancer specimens were classified with 81.2% sensitivity and 80.0% specificity, and cancer versus normal specimens were classified with 77.8% sensitivity and 79.3% specificity. Utilizing only images with greater than of 75% of the field of view containing signal improved sensitivity and specificity for cancer versus normal to 81.5% and 81.1%. These results suggest that using SHG to visualize collagen structure in ovaries could help with early cancer detection.
University of Arizona, Biomedical Engineering, 1657 E. Helen Street, Building 240, P.O. Box 210240, Tucson, Arizona 85721, USA.
Jennifer M
JM
Watson
Photini F
PF
Rice
Samuel L
SL
Marion
Molly A
MA
Brewer
John R
JR
Davis
Jeffrey J
JJ
Rodriguez
Urs
U
Utzinger
Patricia B
PB
Hoyer
Jennifer K
JK
Barton
D000465:Algorithms; D000818:Animals; D005260:Female; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D051379:Mice; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D010051:Ovarian Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity