Diffusion tensor imaging in a symptomatic patient with an intra-axial arachnoid cyst.

We present a case of an elderly lady with a symptomatic large intra-axial right frontoparietal arachnoid cyst displacing the corticospinal tract (CST) posteromedially on diffusion tensor imaging. This information assisted the surgeons in confirming the symptomatic nature of the lesion, in planning an appropriate surgical procedure, as well as in prognostication of recovery.