Can diffusion tensor metrics help in preoperative grading of diffusely infiltrating astrocytomas? A retrospective study of 36 cases

Neuroradiology. 2011 Jan;53(1):63-8. doi: 10.1007/s00234-010-0761-y. Epub 2010 Sep 1.


Introduction: Diffusion weighted imaging and diffusion tensor imaging (DTI) give information about the amount and directionality of water diffusion occurring in a given tissue. Here we study the role of diffusion tensor metrics including fractional anisotropy (FA) and spherical anisotropy (CS) in preoperative grading of diffusely infiltrating astrocytomas.

Methods: We performed DTI in 38 patients with pathologically proven diffusely infiltrating astrocytomas, who were classified into two groups, i.e., 15 patients with high-grade astrocytoma (HGAs, WHO grade III and IV) and 23 patients with low-grade astrocytoma (LGAs, WHO grade II). We measured maximum FA and minimum CS values in all cases from tumor. Histopathological diagnosis was established in all cases.

Results: The mean maximum FA values were higher in HGA (0.583 ± 0.104) than LGA (0.295 ± 0.058), while mean minimum CS values were lower in HGA (0.42 ± 0.121) than LGA (0.722 ± 0.061). The difference in the diffusion tensor indices between HGA and LGA was found to be statistically significant with P value of <0.001. Keeping cutoff FA value of 0.4, all HGAs showed higher maximum FA values, and all LGAs showed lower maximum FA values. Also, all HGAs showed minimum CS values less than a cutoff value of 0.6, and all LGAs showed minimum CS values higher than 0.6.

Conclusion: Diffusion tensor metrics such as maximum FA and minimum CS can help to differentiate HGA from LGA.

MeSH terms

  • Adult
  • Aged
  • Astrocytoma / pathology*
  • Brain Neoplasms / pathology*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Invasiveness / pathology
  • Observer Variation
  • Preoperative Care / methods
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Young Adult