Development and reliability of the new endoscopic virtual chromoendoscopy score: the PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis

Marietta Iacucci, Marco Daperno, Mark Lazarev, Razvan Arsenascu, Gian Eugenio Tontini, Oluseyi Akinola, Xianyong Sean Gui, Vincenzo Villanacci, Martin Goetz, Mark Lowerison, Brendan Cord Lethebe, Maurizio Vecchi, Helmut Neumann, Subrata Ghosh, Raf Bisschops, Ralf Kiesslich

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Background and Aims Endoscopic inflammation and healing are important therapeutic endpoints in ulcerative colitis (UC). We developed and validated a new electronic virtual chromoendoscopy (EVC) score that could reflect the full spectrum of mucosal and vascular changes including mucosal healing in UC. Methods Eight participants reviewed a 60-minute training module outlining 3 different i-SCAN modes demonstrating the entire spectrum of inflammatory mucosal and vascular changes in UC. Performance characteristics in endoscopic scoring and predicting the histologic inflammation with EVC (i-SCAN) by using 20 video clips before (pre-test) and after (post-test) were evaluated. Exploratory univariate factor analysis was performed on Paddington International Virtual Chromoendoscopy Score (PICaSSO) covariates for mucosal and vascular score separately. Subsequently, a proportional odds logistic regression model for the prediction of histologic scores was analyzed. Results The interobserver agreement for Mayo endoscopic score in the pre-test (κ =.85; 95% CI,.78-.90) and the post-test (κ =.85; 95% CI,.77-.90) evaluation were very good. This was also true for the Ulcerative Colitis Endoscopic Index of Severity in the pre-test and post-test score interobserver agreement (κ =.86; 95% CI,.77-.92; and κ =.84; 95% CI,.75-.91, respectively). The interobserver agreement of the PICaSSO endoscopic score was very good in the pre-test and post-test evaluations (κ =.92; 95% CI,.87-.96; and κ =.89; 95% CI,.84-.94, respectively). The accuracy of the overall PICaSSO in assessing histologic abnormalities and inflammation by Harpaz score was 57% (95% CI, 48%-65%), by Robarts Histological Index 72% (95% CI, 64%-79%), and by the extent, chronicity, activity, plus system (full spectrum of histologic changes) 83% (95% CI, 76%-88%). Conclusions The EVC score “PICaSSO” showed very good interobserver agreement. The new EVC score may be used to define the endoscopic findings of mucosal and vascular healing in UC and reflected the full spectrum of histologic changes.

Original languageEnglish (US)
Pages (from-to)1118-1127.e5
JournalGastrointestinal endoscopy
Issue number6
StatePublished - Dec 2017

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Gastroenterology


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