Diffuse brain oedema in idiopathic intracranial hypertension: a quantitative magnetic resonance imaging study

Objectives: To investigate the hypothesis that idiopathic intracranial hypertension is associated with diffuse brain oedema, using quantitative magnetic resonance imaging. Methods: Values for the mean diffusivity of water (<D>) and the proton longitudinal relaxation time (T1) were measured for various brain regions in 10 patients with idiopathic intracranial hypertension and 10 age, sex, and weight matched controls. Results: No significant differences in <D> and T1 values were found between patient and control groups in any of the brain regions investigated. Conclusions: The results suggest that idiopathic intracranial hypertension is not associated with abnormalities of convective transependymal water flow leading to diffuse brain oedema.