title: Knee in early juvenile rheumatoid arthritis: MR imaging findings.
abstract: OBJECTIVE
  To determine the magnetic resonance (MR) imaging findings in the knee in early juvenile rheumatoid arthritis.
  
  
  METHODS
  MR imaging (1.5 T) was performed in the more symptomatic knee in 30 children with juvenile rheumatoid arthritis with a symptom duration 1 year or less. Conventional, fast spin-echo, three-dimensional gradient-echo, and gadolinium-enhanced T1-weighted images were assessed. Two radiologists independently read the images, and a third resolved disagreements. These images were compared with knee radiographs in 27 children.
  
  
  RESULTS
  Mean maximal synovial thickness was 4.8 mm +/- 2.4 (SD). Mean synovial volume was 15.4 mL +/- 10.8. Suprapatellar joint effusions were seen in 26 (87%) of 30 knees, meniscal hypoplasia in 11 (37%) of 30 knees, and abnormal epiphyseal marrow in eight (27%) of 30 knees. Three knees had articular cartilage contour irregularity, fissures, and/or thinning. One knee had a bone erosion. Knee radiographs showed suprapatellar fullness in 78% of the knees, joint space narrowing in one knee, and no bone abnormalities.
  
  
  CONCLUSIONS
  Synovial hypertrophy and joint effusions are the most frequent MR imaging findings of knees in early juvenile rheumatoid arthritis. Early in the disease, radiographically occult cartilage and bone erosions are uncommonly seen at MR imaging. The potential relationship of synovitis to cartilage abnormalities deserves further study.
authors.affiliation: Department of Radiology, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA. gylys.morin@chmcc.org
authors.forename: V M
authors.initials: VM
authors.lastname: Gylys-Morin
authors.forename: T B
authors.initials: TB
authors.lastname: Graham
authors.forename: J S
authors.initials: JS
authors.lastname: Blebea
authors.forename: B J
authors.initials: BJ
authors.lastname: Dardzinski
authors.forename: T
authors.initials: T
authors.lastname: Laor
authors.forename: N D
authors.initials: ND
authors.lastname: Johnson
authors.forename: A E
authors.initials: AE
authors.lastname: Oestreich
authors.forename: M H
authors.initials: MH
authors.lastname: Passo
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography