title: Magnetic resonance imaging findings in juvenile spondyloarthropathy and effects of treatment observed on subsequent imaging.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) is often used to diagnose and monitor treatment effects of juvenile spondyloarthropathy (SpA). Our objective was to describe MRI findings in juvenile SpA and determine predictors of active sacroiliitis and response to treatment.
  
  
  METHODS
  Children who had MRI of the sacroiliac (SI) joints and were referred to the pediatric rheumatology clinic from 2009 to 2012 were retrospectively studied. The clinical parameters, laboratory studies and findings on MRI were collected and a composite score ratio (CR) was calculated for both SI joints on each MRI study based on a semi-quantitative scale that included evaluation of bone marrow edema (BME), synovial enhancement (SE), and erosions (ER). The findings on MRI were correlated with clinical and laboratory values.
  
  
  RESULTS
  50 subjects who underwent 76 MRI for suspected or known SpA were included in the study. Sacroiliitis was seen in 48 MRIs in 32 subjects. Of the subjects with sacroiliitis, mean age ± standard deviation was 13.7 ± 2.6 years, 71% were male and 41% were HLA B27 positive. SE without BME was seen in 31% cases of sacroiliitis. In subjects with sacroiliitis, 79% also had hip arthritis and 41% had enthesitis of the pelvic region on MRI. In 38% of subjects with sacroiliitis, physical exam was not indicative of sacroiliitis or hip arthritis. Longitudinal data were available for 13 subjects. Sacroiliitis on MRI improved in 9 subjects with the greatest improvement in MRI composite score ratio after initiation of etanercept therapy. CR improvement was due to improvement of BME and SE components, while the ER score remained the same or worsened in all but 1 subject.
  
  
  CONCLUSIONS
  History, physical exam or laboratory data may not predict sacroiliitis in children. Magnetic resonance imaging plays a valuable role in the initial evaluation and later treatment monitoring of children with spondyloarthropathy. Synovial enhancement is significantly reduced after treatment, and unlike adults, synovial enhancement may be detected without accompanying bone marrow edema, which suggests gadolinium contrast may be an important component in the assessment of children with spondyloarthropathy.
authors: Children's Hospital Colorado Pediatric Rheumatology, 13123 East 16th Street, Box B311, 80045 Aurora, CO, USA.
authors: Clara
authors: C
authors: Lin
authors: UCSF Pediatric Radiology, 505 Parnassus Ave, Moffitt Room: M396, Box 0628, 94143 San Francisco, CA, USA.
authors: John D
authors: JD
authors: MacKenzie
authors: UCSF Pediatric Radiology, 505 Parnassus Ave, Moffitt Room: M396, Box 0628, 94143 San Francisco, CA, USA.
authors: Jesse L
authors: JL
authors: Courtier
authors: UCSF Pediatric Radiology, 505 Parnassus Ave, Moffitt Room: M396, Box 0628, 94143 San Francisco, CA, USA.
authors: Jeffrey T
authors: JT
authors: Gu
authors: Floating Hospital for Children @ Tufts Medical Center, 800 Washington Street #190, 02111 Boston, MA, USA.
authors: Diana
authors: D
authors: Milojevic
mesh_terms: D000293:Adolescent; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D002061:Bursa, Synovial / Q000473:pathology*; D002648:Child; D000068800:Etanercept; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012446:Sacroiliac Joint / Q000473:pathology*; D025242:Spondylarthropathies / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D014481:United States
chemical_list: D018501:Antirheumatic Agents; D015796:HLA-B27 Antigen; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha; D000068800:Etanercept
keywords: Enthesitis-related arthritis; MRI; Sacroiliitis; Spondyloarthopathy