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

[hydrocephalus with stenosis of the aqueduct of sylvius]

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