Utility of apparent diffusion coefficient ratios in distinguishing common pediatric cerebellar tumors

Acad Radiol. 2012 Jul;19(7):794-800. doi: 10.1016/j.acra.2012.03.004. Epub 2012 Apr 17.


Rationale and objectives: The aim of this study was to identify clinically useful tumor/normal brain apparent diffusion coefficient (ADC) ratios for distinguishing common pediatric cerebellar tumors.

Materials and methods: Review of medical records revealed 79 patients with cerebellar tumors who underwent preoperative magnetic resonance imaging, including diffusion-weighted imaging sequences, and surgery. There were 31 pilocytic astrocytomas, 27 medulloblastomas, 14 ependymomas, and seven atypical teratoid/rhabdoid tumors. ADC values were measured by placing regions of interest on the solid tumor and normal brain parenchyma by two reviewers. Tumor/normal brain ADC ratios were calculated.

Results: Mean ADC values of the pilocytic astrocytomas were greater than those of ependymomas, whose mean ADC values were greater than those of medulloblastomas and atypical teratoid/rhabdoid tumors. Using a tumor/normal brain ADC ratio threshold of 1.70 to distinguish pilocytic astrocytomas from ependymomas, sensitivity of 92% and specificity of 79% were achieved. A tumor/normal brain ADC ratio threshold of 1.20 enabled the sorting of ependymomas from medulloblastomas with sensitivity of 93% and specificity of 88%.

Conclusions: Tumor/normal brain ADC ratios allow the distinguishing of common pediatric cerebellar tumors.

MeSH terms

  • Adolescent
  • Astrocytoma / diagnosis*
  • Cerebellar Neoplasms / diagnosis*
  • Cerebellar Neoplasms / pathology
  • Child
  • Child, Preschool
  • Diagnosis, Differential
  • Diffusion Magnetic Resonance Imaging*
  • Ependymoma / diagnosis*
  • Female
  • Humans
  • Infant
  • Magnetic Resonance Imaging
  • Male
  • Medulloblastoma / diagnosis*
  • Rhabdoid Tumor / diagnosis*
  • Sensitivity and Specificity
  • Teratoma / diagnosis