title: Accuracy of i-Scan for Optical Diagnosis of Colonic Polyps: A Meta-Analysis.
abstract: BACKGROUND
  i-Scan is a novel virtual chromoendoscopy system designed to enhance surface and vascular patterns to improve optical diagnostic performance. Numerous prospective studies have been done to evaluate the accuracy of i-Scan in differentiating colonic neoplasms from non-neoplasms. i-Scan could be an effective endoscopic technique for optical diagnosis of colonic polyps.
  
  
  OBJECTIVE
  Our aim of this study was to perform a meta-analysis of published data to establish the diagnostic accuracy of i-Scan for optical diagnosis of colonic polyps.
  
  
  METHODS
  We searched PubMed, Medline, Elsevier ScienceDirect and Cochrane Library databases. We used a bivariate meta-analysis following a random effects model to summarize the data and plotted hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve (AUC) serves as an indicator of the diagnostic accuracy.
  
  
  RESULTS
  The meta-analysis included a total of 925 patients and 2312 polyps. For the overall studies, the area under the HSROC curve was 0.96. The summary sensitivity was 90.4% (95%CI 85%-94.1%) and specificity was 90.9% (95%CI 84.3%-94.9%). In 11 studies predicting polyps histology in real-time, the summary sensitivity and specificity was 91.5% (95%CI 85.7%-95.1%) and 92.1% (95%CI 84.5%-96.1%), respectively, with the AUC of 0.97. For three different diagnostic criteria (Kudo, NICE, others), the sensitivity was 86.3%, 93.0%, 85.0%, respectively and specificity was 84.8%, 94.4%, 91.8%, respectively.
  
  
  CONCLUSIONS
  Endoscopic diagnosis with i-Scan has accurate optical diagnostic performance to differentiate neoplastic from non-neoplastic polyps with an area under the HSROC curve exceeding 0.90. Both the sensitivity and specificity for diagnosing colonic polyps are over 90%.
authors.affiliation: Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China.
authors.forename: Chuan-Guo
authors.initials: CG
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ji
authors.affiliation: Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Li
mesh_terms: D003106:Colon / Q000473:pathology; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity