Taylor SA¹, Mallett S², Bhatnagar G¹, Morris S³, Quinn L², Tomini F³, Miles A⁴, Baldwin-Cleland R⁵, Bloom S⁶, Gupta A⁵, Hamlin PJ⁷, Hart AL⁸, Higginson A⁹, Jacobs I¹⁰, McCartney S⁶, Murray CD¹¹, Plumb AA¹, Pollok RC¹², Rodriguez-Justo M¹³, Shabir Z¹⁴, Slater A¹⁵, Tolan D¹⁶, Travis S¹⁷, Windsor A¹⁸, Wylie P¹⁹, Zealley I²⁰, Halligan S¹. Health Technol Assess. 2019 Aug;23(42):1-162. doi: 10.3310/hta23420.

Author information

1 Centre for Medical Imaging, University College London, London, UK.

2 Institute of Applied Health Research, National Institute for Health Research Birmingham Biomedical Research Centre, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.

3 Applied Health Research, University College London, London, UK.

4 Department of Psychological Sciences, Birkbeck, University of London, London, UK.

5 Intestinal Imaging Centre, St Mark's Hospital, London North West University Healthcare NHS Trust, Harrow, UK.

6 Department of Gastroenterology, University College Hospital, London, UK.

7 Department of Gastroenterology, St James's University Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK.

8 Inflammatory Bowel Disease Unit, St Mark's Hospital, London North West University Healthcare NHS Trust, Harrow, UK.

9 Department of Radiology, Portsmouth Hospitals NHS Trust, Portsmouth, UK.

10 Independent patient representative, c/o Centre for Medical Imaging, University College London, London, UK.

11 Department of Gastroenterology and Endoscopy, Royal Free London NHS Foundation Trust, London, UK.

12 Department of Gastroenterology, St George's Hospital, London, UK.

13 Department of Histopathology, University College Hospital, London, UK.

14 Comprehensive Clinical Trials Unit, Institute of Clinical Trials and Methodology, University College London, London, UK.

15 Oxford University Hospitals NHS Foundation Trust, Oxford, UK.

16 Department of Radiology, St James's University Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK.

17 Translational Gastroenterology Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.

18 Department of Surgery, University College Hospital, London, UK.

19 Department of Radiology, Royal Free London NHS Foundation Trust, London, UK.

20 Department of Radiology, Ninewells Hospital, Dundee, UK.

Abstract

BACKGROUND: Magnetic resonance enterography and enteric ultrasonography are used to image Crohn's disease patients. Their diagnostic accuracy for presence, extent and activity of enteric Crohn's disease was compared.

OBJECTIVE: To compare diagnostic accuracy, observer variability, acceptability, diagnostic impact and cost-effectiveness of magnetic resonance enterography and ultrasonography in newly diagnosed or relapsing Crohn's disease.

DESIGN: Prospective multicentre cohort study.

SETTING: Eight NHS hospitals.

PARTICIPANTS: Consecutive participants aged ≥ 16 years, newly diagnosed with Crohn's disease or with established Crohn's disease and suspected relapse.

INTERVENTIONS: Magnetic resonance enterography and ultrasonography.

MAIN OUTCOME MEASURES: The primary outcome was per-participant sensitivity difference between magnetic resonance enterography and ultrasonography for small bowel Crohn's disease extent. Secondary outcomes included sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease extent, and sensitivity and specificity for small bowel Crohn's diseaseand colonic Crohn's disease presence; identification of active disease; interobserver variation; participant acceptability; diagnostic impact; and cost-effectiveness.

RESULTS: Out of the 518 participants assessed, 335 entered the trial, with 51 excluded, giving a final cohort of 284 (133 and 151 in new diagnosis and suspected relapse cohorts, respectively). Across the whole cohort, for small bowel Crohn's disease extent, magnetic resonance enterography sensitivity [80%, 95% confidence interval (CI) 72% to 86%] was significantly greater than ultrasonography sensitivity (70%, 95% CI 62% to 78%), with a 10% difference (95% CI 1% to 18%; p = 0.027). For small bowelCrohn's disease extent, magnetic resonance enterography specificity (95%, 95% CI 85% to 98%) was significantly greater than ultrasonography specificity (81%, 95% CI 64% to 91%), with a 14% difference (95% CI 1% to 27%). For small bowel Crohn's diseasepresence, magnetic resonance enterography sensitivity (97%, 95% CI 91% to 99%) was significantly greater than ultrasonography sensitivity (92%, 95% CI 84% to 96%), with a 5% difference (95% CI 1% to 9%). For small bowel Crohn's disease presence, magnetic resonance enterography specificity was 96% (95% CI 86% to 99%) and ultrasonography specificity was 84% (95% CI 65% to 94%), with a 12% difference (95% CI 0% to 25%). Test sensitivities for small bowel Crohn's disease presence and extent were similar in the two cohorts. For colonic Crohn's disease presence in newly diagnosed participants, ultrasonography sensitivity (67%, 95% CI 49% to 81%) was significantly greater than magnetic resonance enterography sensitivity (47%, 95% CI 31% to 64%), with a 20% difference (95% CI 1% to 39%). For active small bowel Crohn's disease, magnetic resonance enterography sensitivity (96%, 95% CI 92% to 99%) was significantly greater than ultrasonography sensitivity (90%, 95% CI 82% to 95%), with a 6% difference (95% CI 2% to 11%). There was some disagreement between readers for both tests. A total of 88% of participants rated magnetic resonance enterography as very or fairly acceptable, which is significantly lower than the percentage (99%) of participants who did so for ultrasonography. Therapeutic decisions based on magnetic resonance enterography alone and ultrasonography alone agreed with the final decision in 122 out of 158 (77%) cases and 124 out of 158 (78%) cases, respectively. There were no differences in costs or quality-adjusted life-years between tests.

LIMITATIONS: Magnetic resonance enterography and ultrasonography scans were interpreted by practitioners blinded to clinical data (but not participant cohort), which does not reflect use in clinical practice.

CONCLUSIONS: Magnetic resonance enterography has higher accuracy for detecting the presence, extent and activity of small bowel Crohn's disease than ultrasonography does. Both tests have variable interobserver agreement and are broadly acceptable to participants, although ultrasonography produces less participant burden. Diagnostic impact and cost-effectiveness are similar. Recommendations for future work include investigation of the comparative utility of magnetic resonance enterography and ultrasonography for treatment response assessment and investigation of non-specific abdominal symptoms to confirm or refute Crohn's disease.

TRIAL REGISTRATION: Current Controlled Trials ISRCTN03982913.

FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 42. See the NIHR Journals Library website for further project information.