title: Apparent diffusion coefficient maps of pediatric mass lesions with free-breathing diffusion-weighted magnetic resonance: feasibility study.
abstract: OBJECTIVE
  To assess the technical feasibility of apparent diffusion coefficient (ADC) mapping based on free-breathing diffusion-weighted magnetic resonance (DW-MR) outside the CNS in children.
  
  
  METHODS
  Twelve children with mass lesions of varied histopathology were scanned with short-tau inversion recovery (STIR), contrast-enhanced T1-weighted (CE-T1W), and diffusion-weighted (b=0, 500 and 1000 s/mm2) sequences. ADC maps were calculated. Lesion-to-background signal intensity ratios were measured and compared between STIR/CE-T1W/ADC overall (Friedman test) and between viable embryonal tumors and other lesions (Kruskal-Wallis test).
  
  
  RESULTS
  ADC maps clearly depicted all lesions. Lesion-to-background signal intensity ratios of STIR (median 3.7), CE-T1W (median 1.4), and ADC (median 1.6) showed no overall difference (chi-square=3.846; P=0.146), and there was no difference between viable embryonal tumors and other lesions within STIR/CE-T1W/ADC (chi-square 1.118/0.669/<0.001; P=0.290/0.414/1.000, respectively).
  
  
  CONCLUSIONS
  ADC mapping is feasible in free-breathing imaging of pediatric mass lesions outside the CNS using standard clinical equipment.
authors.affiliation: Department of Haematology/Oncology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom. olseno@gosh.nhs.uk
authors.forename: O E
authors.initials: OE
authors.lastname: Olsen
authors.forename: N J
authors.initials: NJ
authors.lastname: Sebire
mesh_terms: D000293:Adolescent; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000473:pathology*; D018709:Statistics, Nonparametric