Shankar Kumar1, Thomas Parry1, Sue Mallett1, Gauraang Bhatnagar1, Andrew Plumb1, Shaun Walsh2, Nigel Scott3, Ruchi Tandon4, Heung Chong5, John du Parcq5, Adrianna Martinez6, Morgan Moorghen6, Manuel Rodriguez-Justo7, Steve Halligan1, Stuart Taylor1. 1. Centre for Medical Imaging, University College London (UCL), London, UK. 2. Department of Pathology, Ninewells Hospital and Medical School, Dundee, UK. 3. Department of Histopathology, Leeds Teaching Hospitals NHS Trust, Leeds, UK. 4. Department of Cellular Pathology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK. 5. Department of Cellular Pathology,St George's University Hospitals NHS Foundation Trust London, UK. 6. Department of Cellular Pathology, St Mark's Hospital, London North West University Healthcare NHS Trust, London, UK. 7. Department of Histopathology, University College Hospital NHS Foundation Trust, London, UK.
Abstract
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>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.
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>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.
Authors: Shankar Kumar; Andrew Plumb; Sue Mallett; Gauraang Bhatnagar; Stuart Bloom; Caroline S Clarke; John Hamlin; Ailsa L Hart; Ilan Jacobs; Simon Travis; Roser Vega; Steve Halligan; Stuart Andrew Taylor Journal: BMJ Open Date: 2022-10-03 Impact factor: 3.006