SummaryBackgroundMagnetic resonance enterography (MRE) and ultrasound are used to image Crohn's disease, but their comparative accuracy for assessing disease extent and activity is not known with certainty. Therefore, we did a multicentre trial to address this issue.MethodsWe recruited patients from eight UK hospitals. Eligible patients were 16 years or older, with newly diagnosed Crohn's disease or with established disease and suspected relapse. Consecutive patients had MRE and ultrasound in addition to standard investigations. Discrepancy between MRE and ultrasound for the presence of small bowel disease triggered an additional investigation, if not already available. The primary outcome was difference in per-patient sensitivity for small bowel disease extent (correct identification and segmental localisation) against a construct reference standard (panel diagnosis). This trial is registered with the International Standard Randomised Controlled Trial, number ISRCTN03982913, and has been completed.Findings284 patients completed the trial (133 in the newly diagnosed group, 151 in the relapse group). Based on the reference standard, 233 (82%) patients had small bowel Crohn's disease. The sensitivity of MRE for small bowel disease extent (80% [95% CI 72–86]) and presence (97% [91–99]) were significantly greater than that of ultrasound (70% [62–78] for disease extent, 92% [84–96] for disease presence); a 10% (95% CI 1–18; p=0·027) difference for extent, and 5% (1–9; p=0·025) difference for presence. The specificity of MRE for small bowel disease extent (95% [85–98]) was significantly greater than that of ultrasound (81% [64–91]); a difference of 14% (1–27; p=0·039). The specificity for small bowel disease presence was 96% (95% CI 86–99) with MRE and 84% (65–94) with ultrasound (difference 12% [0–25]; p=0·054). There were no serious adverse events.InterpretationBoth MRE and ultrasound have high sensitivity for detecting small bowel disease presence and both are valid first-line investigations, and viable alternatives to ileocolonoscopy. However, in a national health service setting, MRE is generally the preferred radiological investigation when available because its sensitivity and specificity exceed ultrasound significantly.FundingNational Institute of Health and Research Health Technology Assessment.

Up to 25 % colorectal adenomas are missed during colonoscopy. The aim of this study was to investigate whether the endocuff could improve polyp detection in an organized bowel cancer screening program (BCSP). This parallel group, single-blinded, randomized controlled trial included patients with positive fecal occult blood test (FOBT) who were attending for BCSP colonoscopy. The primary outcome was the number of polyps per patient. Secondary outcomes included the number of adenomas per patient, adenoma and polyp detection rates, and withdrawal times. A total of 534 BCSP patients were randomized to endocuff-assisted or standard colonoscopy. The mean age was 67 years and the male to female ratio was 1.8:1. We detected no significant difference in the number of polyps per patient (standard 1.8, endocuff 1.6; = 0.44), adenomas per patient (standard 1.4, endocuff 1.3; = 0.54), polyp detection rate (standard 69.8 %, endocuff 70.3 %; = 0.93), adenoma detection rate (standard 63.0 %, endocuff 60.9 %; = 0.85), advanced adenoma detection rate (standard 18.5 %, endocuff 16.9 %; = 0.81), and cancer detection rate (standard 5.7 %, endocuff 5.3 %; = 0.85). The mean withdrawal time was significantly shorter among patients in the endocuff group compared with the standard colonoscopy group (16.9 vs. 19.5 minutes; < 0.005). The endocuff had to be removed in 17/266 patients (6.4 %) because of inability to pass through the sigmoid colon. This study did not find improved polyp or adenoma detection with endocuff-assisted colonoscopy in the FOBT-positive BCSP population. A shorter withdrawal time with endocuff may reflect improved views and stability provided by the endocuff.Trial registered at ClinicalTrials.gov (NCT02529007).

Background and study aims: Mucosal views can be impaired by residual bubbles and mucus during gastroscopy. This study aimed to determine whether a pre-gastroscopy drink containing simethicone and N-acetylcysteine improves mucosal visualisation. Patients and methods: We conducted a randomized controlled trial recruiting 126 subjects undergoing routine gastroscopy. Subjects were randomized 1:1:1 to receive: A—pre-procedure drink of water, simethicone and N-acetylcysteine (NAC); B—water alone; or C—no preparation. Study endoscopists were blinded to group allocation. Digital images were taken at 4 locations (lower esophagus/upper gastric body/antrum/fundus), and rated for mucosal visibility (MV) using a 4-point scale (1 = best, 4 = worst) by 4 separate experienced endoscopists. The primary outcome measure was mean mucosal visibility score (MVS). Secondary outcome measures were procedure duration and volume of fluid flush required to achieve adequate mucosal views. Results: Mean MVS for Group A was significantly better than for Group B (1.35 vs 2.11, P < 0.001) and Group C (1.35 vs 2.21, P < 0.001).Mean flush volume required to achieve adequate mucosal views was significantly lower in Group A than Group B (2.0 mL vs 31.5 mL, P = 0.001) and Group C (2.0 mL vs 39.2 mL P < 0.001). Procedure duration did not differ significantly between any of the 3 groups.MV scores at each of the 4 locations demonstrated significantly better mucosal visibility in Group A compared to Group B and Group C (P < 0.0025 for all comparisons). Conclusions: A pre-procedure drink containing simethicone and NAC significantly improves mucosal visibility during gastroscopy and reduces the need for flushes during the procedure. Effectiveness in the lower esophagus demonstrates potential benefit in Barrett’s oesophagus surveillance gastroscopy.

Background and Aims The simplified magnetic resonance enterography (MRE) index (sMARIA), London and “extended” London scoring systems are widely used in Crohn’s disease (CD) to assess disease activity, although validation studies have usually been single centre, retrospective and/or used few readers. Here, we evaluated these MRE indices within a prospective multicentre, multireader diagnostic accuracy trial. Methods A subset of participants (newly diagnosed or suspected of relapse) recruited to the METRIC trial with available terminal ileal (TI) biopsies was included. Using pre-specified thresholds, the sensitivity and specificity of sMARIA, London and “extended” London scores for active and severe (sMARIA) TI CD were calculated using different thresholds for the histological activity index (HAI). Results We studied 111 patients (median 29 years, interquartile range 21-41, 75 newly diagnosed, 36 suspected relapse) from 7 centres, of whom 22 had no active TI CD (HAI=0), 39 mild (HAI=1), 13 moderate (HAI=2), and 37 severe CD activity (HAI=3). In total, 26 radiologists prospectively scored MRE datasets as per their usual clinical practice. Sensitivity and specificity for active disease (HAI&gt;0) were 83% (95% confidence interval 74-90%) and 41% (23-61%) for sMARIA, 76% (67-84%) and 64% (43-80%) for the London score, and 81% (72-88%) and 41% (23-61%) for the “extended” London score, respectively. The sMARIA had 84% (69-92%) sensitivity and 53% (41-64%) specificity for severe CD. Conclusions When tested at their proposed cut-offs in a real-world setting, sMARIA, London and “extended” London indices achieve high sensitivity for active TI disease against a histological reference standard, but specificity is low.

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