title: One-year followup study on clinical findings and changes in magnetic resonance imaging-based disease activity scores in juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To evaluate whether clinical disease activity findings during 1-year followup of patients with juvenile idiopathic arthritis (JIA) is associated with changes of magnetic resonance imaging (MRI)-based disease activity scores.
  
  
  METHODS
  Patients with JIA who had active knee involvement were studied using an open-bore MRI. After followup of a median of 1.3 years, patients were re-evaluated and classified as improved or unimproved according to the American College of Rheumatology Pediatric-50 (ACR-Ped50) criteria. Baseline and followup MRI features were scored by 2 readers using the Juvenile Arthritis MRI Scoring (JAMRIS) system, comprising validated scores for synovial hypertrophy, bone marrow changes, cartilage lesions, and bone erosions.
  
  
  RESULTS
  Data of 40 patients were analyzed (62.5% female, mean age 12.2 yrs). After followup, 27 patients (67.5%) were classified as clinically improved, whereas 13 patients (32.5%) showed no clinical improvement. The clinically improved patients showed a significant reduction in synovial hypertrophy scores during followup (p < 0.001), with substantial effects (standardized response mean -0.70). No such changes were observed for any of the other MRI features. Significant differences were detected regarding a change in synovial hypertrophy scores comparing clinically improved and unimproved patients (p = 0.004), without statistically significant differences for changes in scores for bone marrow changes (p = 0.079), cartilage lesions (p = 0.165), and bone erosions (p = 0.078).
  
  
  CONCLUSIONS
  This is one of the first studies to provide evidence for MRI-based improvement upon followup in JIA patients with knee involvement. There is a strong association with clinical improvement according to the ACR-Ped50 criteria and changes in MRI-based synovial hypertrophy scores, supporting the role of MRI as a responsive outcome measure to evaluate disease activity with antiinflammatory treatment strategies.
authors.affiliation: From the Department of Radiology, Academic Medical Center, and the Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease of Emma Children's Hospital AMC, University of Amsterdam; the Department of Pediatric Rheumatology, St. Lucas Andreas Hospital; the Department of Pediatric Rheumatology, Reade, Amsterdam, the Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: Hemke
authors.forename: Mira
authors.initials: M
authors.lastname: van Veenendaal
authors.forename: J Merlijn
authors.initials: JM
authors.lastname: van den Berg
authors.forename: Koert M
authors.initials: KM
authors.lastname: Dolman
authors.forename: Marion A J
authors.initials: MA
authors.lastname: van Rossum
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
authors.forename: Taco W
authors.initials: TW
authors.lastname: Kuijpers
mesh_terms: D000293:Adolescent; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000188:drug therapy / Q000473:pathology*; D001853:Bone Marrow / Q000473:pathology*; D002648:Child; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents
keywords: DISEASE ACTIVITY; JUVENILE IDIOPATHIC ARTHRITIS; KNEE; MAGNETIC RESONANCE IMAGING