title: Reliability and responsiveness of the Juvenile Arthritis MRI Scoring (JAMRIS) system for the knee.
abstract: OBJECTIVE
  To assess the reliability and responsiveness of a new Juvenile Arthritis MRI Scoring (JAMRIS) system for evaluating disease activity of the knee.
  
  
  METHODS
  Twenty-five juvenile idiopathic arthritis (JIA) patients with clinical knee involvement were studied using open-bore 1-T MRI. MRI features of synovial hypertrophy, bone marrow changes, cartilage lesions and bone erosions were independently scored by five readers using the JAMRIS system. In addition, the JAMRIS system was determined to be a follow-up parameter by two readers to evaluate the response to therapy in 15 consecutive JIA patients.
  
  
  RESULTS
  Inter-reader (ICCs 0.86-0.95) and intra-reader reliability (ICCs 0.92-1.00) for the scoring of JAMRIS features was good. Reliability of the actual scores and changes in scores over time was good for all items: ICCs 0.89-1.00, 0.87-1.00, respectively. Concerning therapy response, the mean synovial hypertrophy scores decreased significantly (mean 1.1 point; P < 0.001, SRM = -0.65). No change was observed with respect to bone marrow change, cartilage lesion and bone erosion scores.
  
  
  CONCLUSIONS
  The JAMRIS proved to be a simple and highly reliable assessment score in the evaluation of JIA disease activity of the knee. The JAMRIS system may serve as an objective and accurate outcome measure in future research and clinical trials.
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands. r.hemke@amc.nl
authors.forename: Robert
authors.initials: R
authors.lastname: Hemke
authors.forename: Marion A J
authors.initials: MA
authors.lastname: van Rossum
authors.forename: Mira
authors.initials: M
authors.lastname: van Veenendaal
authors.forename: Maaike P
authors.initials: MP
authors.lastname: Terra
authors.forename: Eline E
authors.initials: EE
authors.lastname: Deurloo
authors.forename: Milko C
authors.initials: MC
authors.lastname: de Jonge
authors.forename: J Merlijn
authors.initials: JM
authors.lastname: van den Berg
authors.forename: Koert M
authors.initials: KM
authors.lastname: Dolman
authors.forename: Taco W
authors.initials: TW
authors.lastname: Kuijpers
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
mesh_terms: D000293:Adolescent; D000465:Algorithms; D001171:Arthritis, Juvenile / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009426:Netherlands; D020370:Osteoarthritis, Knee / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index