Diffusion Tensor Imaging Tractography in Tumour Workup

A 61yo female presented with left arm dyspraxia and mild left hemiparesis. CT and routine MR imaging showed a mass in the right parietotemporal region with typical appearances of a WHO grade IV astrocytoma (glioblastoma multiforme). The treating neurosurgeon was concerned at the possibility of damaging the corticospinal tracts during resection, and requested diffusion tensor imaging (DTI) with tractography prior to surgery. A post-gadolinium 3D MPRAGE sequence was obtained and coregistered with a 20-direction diffusion weighted sequence with tensor mapping. Seed points were placed on the cerebral peduncles bilaterally to map the corticospinal tracts. The image above shows the enhancing tumour located posterior to the right corticospinal tract, and marked peritumoral vasogenic oedema displacing the tract anteriorly. The normal left corticospinal tract is shown for comparison.

Credit: Dr Jason Wenderoth