Diffusion tensor imaging in hydrocephalus--findings before and after shunt surgery.

Background: To evaluate changes in diffusion tensor imaging (DTI)-derived parameters in patients with hydrocephalus (HC) before and several weeks after shunt surgery.

Methods: Thirteen HC patients were examined with DTI before and after shunt surgery. In a combined region of interest and whole brain voxel-based analysis, different DTI parameters were compared with an age-matched control group.

Results: Alteration of DTI parameters in HC patients and changes after shunt surgery are regionally different. HC patients show an increase in fractional anisotropy values based on increases in parallel diffusivity in the corticospinal tract. On the other hand, reduced fractional anisotropy values are found in the corpus callosum of HC patients. Following shunt surgery, all DTI parameters showed a trend towards normalization, yet differences to healthy control subjects remained.

Conclusion: Our results show that DTI parameter changes are regionally dependent and need a careful interpretation of the underlying diffusivities to serve as a diagnostic or follow-up measure in patients with hydrocephalus.