P587 Intestinal ultrasound (IUS) and magnetic resonance imaging (MRI) for monitoring of response to therapy in luminal Crohn’s disease – a systematic review.

Lovett, G.(1,2)*;Schulberg, J.D.(1,2);Hamilton, A.L.(1,2);Wilding, H.E.(3);Kamm, M.A.(1,2);Wright, E.K.(1,2);

(1)St Vincent's Hospital Melbourne, Department of Gastroenterology, Melbourne, Australia;(2)University of Melbourne, Department of Medicine, Melbourne, Australia;(3)St Vincent's Hospital Melbourne, Library Service, Melbourne, Australia;

Background

Mucosal and transmural healing are associated with better outcomes in Crohn’s disease. Magnetic resonance imaging (MRI) and intestinal ultrasound (IUS) provide non-invasive cross-sectional assessment of disease activity and transmural healing. This systematic review addresses the utility of MRI and IUS in the assessment of disease activity and transmural healing in response to drug therapy when compared to endoscopy in patients with luminal Crohn’s disease.

Methods

Database searches were undertaken (Medline, Embase, Emcare, APA PsycInfo, CINAHL, Cochrane Library) following the PRISMA statement. Studies with ≥10 luminal Crohn’s disease patients with paired endoscopy and imaging (MRI or IUS) following treatment initiation were included. Records were screened on title and abstract, then full text by two independent reviewers.

Results

5760 records were identified, 1707 duplicates removed, 1468 excluded; 2585 screened on title and abstract, 65 underwent full text review, resulting in 24 studies meeting inclusion criteria. 10 studies examined IUS, 12 examined MRI and 2 compared both. There was good correlation between IUS and endoscopic remission with biologic and or thiopurine treatment (k = 0.63, P<0.001; k = 0.73, P<0.001), and good correlation for IUS score and Simple Endoscopic score-Crohn’s disease (SESCD) at baseline and reassessment (r=0.521; P<0.001). Early reduction in bowel wall thickness (BWT) at 4-8 weeks of anti-TNF therapy predicted endoscopic response at 12-38 weeks (AUROC 0.77; OR 10.80 P=0.012). Significant reductions in BWT after 2 weeks of anti-TNF therapy was associated with clinical and endoscopic response at 14 weeks. A significant reduction in BWT as early as 4 weeks with ustekinumab therapy correlated with endoscopic response at 48 weeks (k = 0.21; 95%CI 0.04-0.38). IUS transmural remission rates were higher in colonic disease than terminal ileal disease (OR 2.59; 95%CI 1.43-4.70, P<0.05). MRI MaRIA score had a high accuracy for predicting endoscopic remission (AUROC 0.967; sensitivity 93%, specificity 77%, P<0.05). Intestinal healing detected by MRI and endoscopy after 1 year of anti-TNF was predictive of long-term clinical remission (sensitivity 75%, specificity 72%; P=0.02). The simplified MaRIA score correlates with endoscopic response and was responsive to change after drug therapy (r=0.72; 95%CI 0.53-0.85).

Conclusion

Intestinal ultrasound and magnetic resonance imaging are reliable non-invasive modalities for assessing transmural healing in Crohn’s disease and accurate in monitoring response to drug therapy. Early changes in ultrasound are predictive of response to treatment. Intestinal ultrasound can monitor response to biologic induction.