PT - JOURNAL ARTICLE AU - Yan Li AU - Jost Langhorst AU - Anna Katharina Koch AU - Aydin Demircioglu AU - Felix Nensa AU - Julian Kirchner AU - Karsten Beiderwellen AU - Onofrio Catalano AU - Michael Forsting AU - Ken Herrmann AU - Lale Umutlu TI - Assessment of Ileocolonic Inflammation in Crohn’s Disease: Which Surrogate Marker Is Better—MaRIA, Clermont, or PET/MR Index? Initial Results of a Feasibility Trial AID - 10.2967/jnumed.118.216937 DP - 2019 Jun 01 TA - Journal of Nuclear Medicine PG - 851--857 VI - 60 IP - 6 4099 - http://jnm.snmjournals.org/content/60/6/851.short 4100 - http://jnm.snmjournals.org/content/60/6/851.full SO - J Nucl Med2019 Jun 01; 60 AB - Our objective was to define an 18F-FDG PET/MR enterography index as a hybrid surrogate marker for active ileocolonic inflammation in Crohn’s disease (CD) and assess its diagnostic performance in comparison to validated MR indices (MR index of activity [MaRIA], Clermont score). Methods: Fifty-two CD patients with recurrent symptoms underwent ileocolonoscopy and 18F-FDG PET/MR enterography. Three hundred three ileocolonic segments were assessed for inflammation using MaRIA and the Clermont score as well as the newly defined PET/MR index. On the basis of tobit regression, the PET/MR index was defined as (0.87 × wall thickness) + (1.97 × edema) + (0.83 × ulceration) + (0.55 × SUVmax ratio) + 1.14. The endoscopic activity of inflammation was determined by the simplified endoscopic activity score for CD (SES-CD). Receiver-operating-characteristic curves for each surrogate marker were created and tested against each other using the DeLong test, and diagnostic accuracies were compared using the McNemar test. Correlations between surrogate markers and SES-CD were tested with the Spearman rank correlation test. Results: The PET/MR index showed a comparable sensitivity but a significantly higher specificity and accuracy than MaRIA and the Clermont score in predicting both active and severe inflammation (active inflammation: specificities of 0.933, 0.711, and 0.707 and accuracies of 0.921, 0.739, and 0.736, P < 0.001; severe inflammation: specificities of 0.91, 0.81, and 0.785 and accuracies of 0.914, 0.818, and 0.795, P < 0.01, respectively). All surrogate markers correlated moderately with SES-CD on a segmental basis and a global level (0.5 < ρ < 0.7, all P < 0.001). Conclusion: As a hybrid surrogate marker comprising MR parameters and the PET component, the PET/MR index yielded significantly improved specificity and diagnostic accuracy compared with conventional MR indices (MaRIA and the Clermont score), demonstrating its high potential for noninvasive assessment of CD.