title: Magnetic resonance imaging for evaluation of childhood aplastic anemia.
abstract: OBJECTIVE
  We prospectively evaluated the ability of magnetic resonance imaging (MRI) of the thoraco-lumbar vertebrae to determine the relative amount of red and fatty marrow in children with aplastic anemia.
  
  
  METHODS
  Twenty pediatric patients (ages 1-19 years) with aplastic anemia underwent T1-weighted (T1W, n = 31) and short T1 inversion recovery (STIR, n = 30) MRI of the midline sagittal thoraco-lumbar spine. Bone marrow (BM) biopsies from the posterior iliac crest (n = 29) were also performed. All studies were evaluated by blinded observers; MR grading was based on visual inspection of signal intensity. Biopsy-estimated cellularity was compared with T1W and STIR grading when these were performed within 14 days of each other (n = 16). All studies were compared to a simultaneous absolute neutrophil count (ANC), absolute reticulocyte count (ARC), and platelet count.
  
  
  RESULTS
  BM cellularity estimated by BM biopsy was significantly associated with STIR grading (p = 0.032, Jonckheere-Terpstra test), as were peripheral ANC (p = 0.044), ARC (p = 0.007), and platelet count (p = 0.003). T1W grade was significantly associated with ANC (P = 0.011) but not ARC (p = 0.053) or platelet count (p = 0.377). Biopsy-estimated cellularity was associated with ANC (p = 0.032) and ARC (p = 0.036), but not platelet count (p = 0.282).
  
  
  CONCLUSIONS
  In childhood aplastic anemia patients, STIR (and, to a lesser extent, T1W) MRI of the thoraco-lumbar spine reflects BM activity, as measured by peripheral blood ANC, ARC, and platelet count, and BM cellularity, as measured by BM biopsy. MRI may thus provide a noninvasive measure of hematopoietic status.
authors.affiliation: Department of Hematology-Oncology, St. Jude Children's Research Hospital, Memphis, TN 38101-0318, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Kanwar
authors.forename: W C
authors.initials: WC
authors.lastname: Wang
authors.forename: H T
authors.initials: HT
authors.lastname: Winer-Muram
authors.forename: W M
authors.initials: WM
authors.lastname: Kauffman
authors.forename: S A
authors.initials: SA
authors.lastname: Gronemeyer
authors.forename: D R
authors.initials: DR
authors.lastname: Head
mesh_terms: D000293:Adolescent; D000328:Adult; D000741:Anemia, Aplastic / Q000175:diagnosis*; D001706:Biopsy; D001772:Blood Cell Count; D001853:Bone Marrow / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male