title: Monitoring Crohn's disease during anti-TNF-α therapy: validation of the magnetic resonance enterography global score (MEGS) against a combined clinical reference standard.
abstract: OBJECTIVE
  To assess the ability of magnetic resonance enterography global score (MEGS) to characterise Crohn's disease (CD) response to anti-TNF-α therapy.
  
  
  METHODS
  Thirty-six CD patients (median age 26 years, 20 males) commencing anti-TNF-α therapy with concomitant baseline MRI enterography (MRE) were identified retrospectively. Patients' clinical course was followed and correlated with subsequent MREs. Scan order was randomised and MEGS (a global activity score) was applied by two blinded radiologists. A physician's global assessment of the disease activity (remission, mild, moderate or severe) at the time of MRE was assigned. The cohort was divided into clinical responders and non-responders and MEGS compared according to activity status and treatment response. Interobserver agreement was assessed.
  
  
  RESULTS
  Median MEGS decreased significantly between baseline and first follow-up in responders (28 versus 6, P < 0.001) but was unchanged in non-responders (26 versus 18, P = 0.28). The median MEGS was significantly lower in clinical remission (9) than in moderate (14) or severe (29) activity (P < 0.001). MEGS correlated significantly with clinical activity (r = 0.53; P < 0.001). Interobserver Bland-Altman limits of agreement (BA LoA) were -19.7 to 18.5.
  
  
  CONCLUSIONS
  MEGS decreases significantly in clinical responders to anti-TNF-α therapy but not in non-responders, demonstrates good interobserver agreement and moderate correlation with clinical disease activity.
  
  
  CONCLUSIONS
  • MRI scores of Crohn's activity are used increasingly in clinical practice and therapeutic trials. • Such scores have been advocated as biomarkers of therapeutic response. • MEGS reflects clinical response to anti-TNF-α therapy and the clinical classification of disease activity. • MEGS demonstrates good interobserver agreement.
authors.affiliation: Centre for Medical Imaging, University College London, 3rd floor east, 250 Euston Rd, London, NW1 2PG, UK.|Department of Cancer Imaging, King's College London, St Thomas' Hospital, 4th floor Lambeth Wing, London, SE1 7EH, UK.
authors.forename: Davide
authors.initials: D
authors.lastname: Prezzi
authors.affiliation: Centre for Medical Imaging, University College London, 3rd floor east, 250 Euston Rd, London, NW1 2PG, UK.
authors.forename: Gauraang
authors.initials: G
authors.lastname: Bhatnagar
authors.affiliation: Gastrointestinal Services, University College Hospital, Ground floor west, 250 Euston Road, London, NW1 2PG, UK.
authors.forename: Roser
authors.initials: R
authors.lastname: Vega
authors.affiliation: Centre for Medical Imaging, University College London, 3rd floor east, 250 Euston Rd, London, NW1 2PG, UK.
authors.forename: Jesica
authors.initials: J
authors.lastname: Makanyanga
authors.affiliation: Centre for Medical Imaging, University College London, 3rd floor east, 250 Euston Rd, London, NW1 2PG, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Halligan
authors.affiliation: Centre for Medical Imaging, University College London, 3rd floor east, 250 Euston Rd, London, NW1 2PG, UK. stuart.taylor1@nhs.net.
authors.forename: Stuart Andrew
authors.initials: SA
authors.lastname: Taylor
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D041981:Gastrointestinal Tract / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha
keywords: Biological therapy; Crohn’s disease; Enterography; Magnetic resonance imaging; Therapeutic monitoring