I-scan optical enhancement for the in vivo prediction of diminutive colorectal polyp histology: results from a prospective three-phased multicentre trial

Research output: Contribution to journalArticlepeer-review


  • Entcho Klenske
  • Steffen Zopf
  • Clemens Neufert
  • Andreas Nägel
  • Jürgen Siebler
  • Jürgen Gschossmann
  • Steffen Mühldorfer
  • Lukas Pfeifer
  • Sarah Fischer
  • Francesco Vitali
  • Michelle G. Rath
  • Peter Klare
  • Gian E. Tontini
  • Markus F. Neurath
  • Timo Rath

Colleges, School and Institutes

External organisations

  • University Hospital of Erlangen
  • Klinikum Forchheim
  • Klinikum Bayreuth GmbH
  • University Hospital Heidelberg
  • Technical University Munich
  • IRCCS Policlinico San Donato


Background and aims Dye-less chromoendoscopy is an emerging technology for colorectal polyp characterization. Herein, we investigated whether the newly introduced I-scan optical enhancement (OE) can accurately predict polyp histology in vivo in real-time. Methods In this prospective three-phased study, 84 patients with 230 diminutive colorectal polyps were included. During the first two study phases, five endoscopists assessed whether analysis of polyp colour, surface and vascular pattern under i-scan OE can differentiate in vivo between adenomatous and hyperplastic polyps. Finally, junior and experienced endoscopists (JE, EE, each n = 4) not involved in the prior study phases made a post hoc diagnosis of polyp histology using a static i-scan OE image database. Histopathology was used as a gold-standard in all study phases. Results The overall accuracy of i-scan OE for histology prediction was 90% with a sensitivity, specificity, positive (PPV) and negative prediction value (NPV) of 91%, 90%, 86% and 94%, respectively. In high confidence predictions, the diagnostic accuracy increased to 93% with sensitivity, specificity, PPV and NPV of 94%, 91%, 89% and 96%. Colonoscopy surveillance intervals were predicted correctly in 90% of patients. In the post hoc analysis EE predicted polyp histology under i-scan OE with an overall accuracy of 91%. After a single training session, JE achieved a comparable diagnostic performance for predicting polyp histology with i-scan OE. Conclusion The histology of diminutive colorectal polyps can be accurately predicted with i-scan OE in vivo in real-time. Furthermore, polyp differentiation with i-scan OE appears to require only a short learning curve.


Original languageEnglish
Article numbere0197520
Number of pages13
JournalPLoS ONE
Issue number5
Publication statusPublished - 16 May 2018