title: Computer-aided diagnosis of neoplastic colorectal lesions using 'real-time' numerical color analysis during autofluorescence endoscopy.
abstract: OBJECTIVE
  Differentiating non-neoplastic colorectal lesions from neoplastic lesions during screening colonoscopies is essential to reduce the unnecessary treatment of non-neoplastic lesions. The present study was conducted to verify the diagnostic yields of the computer-aided diagnostic system that enables 'real-time' color analysis of colorectal lesions when applied to autofluorescence endoscopy (AFE).
  
  
  METHODS
  Consecutive patients who were scheduled to undergo a therapeutic colonoscopy in our department were enrolled in this study. The encountered lesions were evaluated in AFE and color-tone sampling was performed. Lesions with green/red (G/R) ratios less than 1.01 were judged to be neoplastic and those with G/R ratios of at least 1.01 were considered to be non-neoplastic. All lesions greater than 5 mm were endoscopically removed and lesions less than 5 mm were biopsied.
  
  
  RESULTS
  During the study period, a total of 32 patients with 102 colorectal lesions were evaluated with AFE. The mean G/R ratio for all neoplastic lesions was 0.86 [95% confidence interval (CI), 0.63-1.01], which was significantly lower than the mean G/R ratio for non-neoplastic lesions (1.12; 95% CI, 0.98-1.26; P<0.001). The mean G/R ratios were 1.36 (95% CI, 1.21-1.57) in normal mucosa, 1.12 (95% CI, 0.98-1.26) in hyperplastic lesions, 0.88 (95% CI, 0.69-1.02) in adenomas, and 0.61 (95% CI, 0.54-0.73) in intramucosal cancers. A G/R ratio cutoff value of 1.01 was applied for discriminating between neoplastic lesions and non-neoplastic lesions, and yielded sensitivity, specificity, positive and negative predictive values of 94.2, 88.9, 95.6, and 85.2%, respectively.
  
  
  CONCLUSIONS
  This diagnostic tool may lead to the reduction of unnecessary treatments for non-neoplastic lesions.
authors.affiliation: Department of Endoscopy, Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan. hiamliveinpeace@gmail.com
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aihara
authors.forename: Shoichi
authors.initials: S
authors.lastname: Saito
authors.forename: Hiroko
authors.initials: H
authors.lastname: Inomata
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ide
authors.forename: Naoto
authors.initials: N
authors.lastname: Tamai
authors.forename: Tomohiko R
authors.initials: TR
authors.lastname: Ohya
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
authors.forename: Shigeki
authors.initials: S
authors.lastname: Amitani
authors.forename: Hisao
authors.initials: H
authors.lastname: Tajiri
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D003106:Colon / Q000473:pathology; D003113:Colonoscopy / Q000379:methods; D003116:Color; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003199:Computer Systems; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D003937:Diagnosis, Differential; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D061848:Optical Imaging / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012985:Software Design