title: Evaluating the apparent diffusion coefficient in MRI studies as a means of determining paediatric brain tumour stages.
abstract: BACKGROUND
  The apparent diffusion coefficient (ADC) in MRI seems to be related to cellularity in brain tumours. Its utility as a tool for distinguishing between histological types and tumour stages remains controversial.
  
  
  METHODS
  We retrospectively evaluated children diagnosed with CNS tumours between January 2008 and December 2013. Data collected were age, sex, histological diagnosis, and location of the tumour. We evaluated the ADC and ADC ratio and correlated those values with histological diagnoses.
  
  
  RESULTS
  The study included 55 patients with a median age of 6 years. Histological diagnoses were pilocytic astrocytoma (40%), anaplastic ependymoma (16.4%), ganglioglioma (10.9%), glioblastoma (7.3%), medulloblastoma (5.5%), and other (20%). Tumours could also be classified as low-grade (64%) or high-grade (36%). Mean ADC was 1.3 for low-grade tumours and 0.9 for high-grade tumours (p=.004). Mean ADC ratios were 1.5 and 1.2 for low and high-grade tumours respectively (p=.025). There were no significant differences in ADC/ADC ratio between different histological types.
  
  
  CONCLUSIONS
  ADC and ADC ratio may be useful in imaging-study based differential diagnosis of low and high-grade tumours, but they are not a substitute for an anatomical pathology study.
authors: Unidad de Hemato-Oncología Pediátrica, Hospital 12 de Octubre, Madrid, España. Electronic address: nere.mdc@gmail.com.
authors: N
authors: N
authors: Domínguez-Pinilla
authors: Unidad de Radiología Pediátrica, Hospital 12 de Octubre, Madrid, España.
authors: A
authors: A
authors: Martínez de Aragón
authors: Unidad de Radiología Pediátrica, Hospital 12 de Octubre, Madrid, España.
authors: S
authors: S
authors: Diéguez Tapias
authors: Unidad de Anatomía Patológica, Hospital 12 de Octubre, Madrid, España.
authors: O
authors: O
authors: Toldos
authors: Unidad de Neurocirugía Pediátrica, Hospital 12 de Octubre, Madrid, España.
authors: J
authors: J
authors: Hinojosa Bernal
authors: Unidad de Hemato-Oncología Pediátrica, Hospital 12 de Octubre, Madrid, España.
authors: M
authors: M
authors: Rigal Andrés
authors: Unidad de Hemato-Oncología Pediátrica, Unidad de Inmunodeficiencias Pediátricas, Hospital 12 de Octubre, Madrid, España.
authors: L I
authors: LI
authors: González-Granado
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D008297:Male; D009367:Neoplasm Staging; D012189:Retrospective Studies
keywords: Apparent diffusion coefficient; Brain tumours; Children; Coeficiente de difusión aparente; Magnetic resonance imaging; Niños; Resonancia magnética; Tumores cerebrales