title: Utility of unenhanced fat-suppressed T1-weighted MRI in children with sickle cell disease -- can it differentiate bone infarcts from acute osteomyelitis?
abstract: BACKGROUND
  Children with sickle cell disease (SCD) are at risk of bone infarcts and acute osteomyelitis. The clinical differentiation between a bone infarct and acute osteomyelitis is a diagnostic challenge. Unenhanced T1-W fat-saturated MR images have been proposed as a potential tool to differentiate bone infarcts from osteomyelitis.
  
  
  OBJECTIVE
  To evaluate the reliability of unenhanced T1-W fat-saturated MRI for differentiation between bone infarcts and acute osteomyelitis in children with SCD.
  
  
  METHODS
  We retrospectively reviewed the records of 31 children (20 boys, 11 girls; mean age 10.6 years, range 1.1-17.9 years) with SCD and acute bone pain who underwent MR imaging including unenhanced T1-W fat-saturated images from 2005 to 2010. Complete clinical charts were reviewed by a pediatric hematologist with training in infectious diseases to determine a clinical standard to define the presence or absence of osteomyelitis. A pediatric radiologist reviewed all MR imaging and was blinded to clinical information. Based on the signal intensity in T1-W fat-saturated images, the children were further classified as positive for osteomyelitis (low bone marrow signal intensity) or positive for bone infarct (high bone marrow signal intensity).
  
  
  RESULTS
  Based on the clinical standard, 5 children were classified as positive for osteomyelitis and 26 children as positive for bone infarct (negative for osteomyelitis). The bone marrow signal intensity on T1-W fat-saturated imaging was not significant for the differentiation between bone infarct and osteomyelitis (P = 0.56). None of the additional evaluated imaging parameters on unenhanced MRI proved reliable in differentiating these diagnoses.
  
  
  CONCLUSIONS
  The bone marrow signal intensity on unenhanced T1-W fat-saturated MR images is not a reliable criterion to differentiate bone infarcts from osteomyelitis in children.
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA, 19104, USA. jorge.delgado.londono@gmail.com.
authors.forename: Jorge
authors.initials: J
authors.lastname: Delgado
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA, 19104, USA.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Bedoya
authors.affiliation: Division of Oncology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Abby M
authors.initials: AM
authors.lastname: Green
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA, 19104, USA.|The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Jaramillo
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA, 19104, USA.|The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Ho-Fung
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000473:pathology*; D001842:Bone and Bones / Q000098:blood supply*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010019:Osteomyelitis / Q000175:diagnosis*; D012189:Retrospective Studies
keywords: Bone infarction; Children; Magnetic resonance imaging; Osteomyelitis; Sickle cell disease