title: Whole-body MRI assessment of disease activity and structural damage in rheumatoid arthritis: first step towards an MRI joint count.
abstract: OBJECTIVE
  The aim of this study was to investigate the ability of whole-body MRI (WBMRI) to visualize inflammation [synovitis, bone marrow oedema (BME) and enthesitis] and structural damage in patients with RA.
  
  
  METHODS
  The 3T WBMR images were acquired in a head-to-toe scan in 20 patients with RA and at least one swollen or tender joint. Short Tau Inversion Recovery and pre- and post-contrast T1-weighted images were evaluated for readability and the presence/absence of inflammation (synovitis, BME and enthesitis) and structural damage (erosions and fat infiltrations) in 76 peripheral joints, 30 entheseal sites and in the spine.
  
  
  RESULTS
  The readability was >70% for all individual joints, except for the most peripheral joints of the hands and feet. Synovitis was most frequent in the wrist, first tarsometatarsal, first CMC joints and glenohumeral joints (67-61%); BME in the wrist, CMC, acromioclavicular and glenohumeral joints (45-35%) and erosions in the wrist, MTP and CMC joints (19-16%). Enthesitis at ≥ 1 site was registered in 16 patients. BME was frequently seen in the cervical (20%) but not the thoracic and lumbar spine, while fat infiltrations and erosions were rare. The intrareader agreement was high (85-100%) for all pathologies. The agreement between WBMRI and clinical findings was low.
  
  
  CONCLUSIONS
  Peripheral and axial inflammation and structural damage at joints and entheses was frequently identified by WBMRI, and more frequently than by clinical examination. WBMRI is a promising tool for evaluation of the total inflammatory load of inflammation (an MRI joint count) and structural damage in RA patients.
authors.affiliation: Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital at Glostrup, Nordre Ringvej 57, Opgang 5, 2600 Glostrup, Denmark. mbaxelsen@gmail.com.
authors.forename: Mette Bjørndal
authors.initials: MB
authors.lastname: Axelsen
authors.forename: Iris
authors.initials: I
authors.lastname: Eshed
authors.forename: Anne
authors.initials: A
authors.lastname: Duer-Jensen
authors.forename: Jakob M
authors.initials: JM
authors.lastname: Møller
authors.forename: Susanne Juhl
authors.initials: SJ
authors.lastname: Pedersen
authors.forename: Mikkel
authors.initials: M
authors.lastname: Østergaard
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D001855:Bone Marrow Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D015897:Comorbidity; D004487:Edema / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007596:Joints / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012216:Rheumatic Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D012720:Severity of Illness Index; D013585:Synovitis / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology
keywords: inflammation; magnetic resonance imaging; rheumatoid arthritis; structural damage; whole-body imaging