Abstract
Background Advanced modalities such as functional magnetic resonance imaging (MRI) and diffusion
MR tractography offer in vivo information about brain networks and are therefore increasingly
used for neurosurgical planning in children also.
Aim This study aims to study the application of routine and advanced tractography algorithms
and its comparison with intraoperative subcortical electrical stimulation.
Method Presurgical functional MRI and MR diffusion tractography were performed on a 6-year-old
patient presenting with seizures, but no motor symptoms, due to a neuroectodermal
tumor in the left central region. Three different tractography algorithms were compared:
deterministic diffusion tensor imaging (DTI)-tracking, probabilistic DTI-tracking,
and probabilistic constrained spherical deconvolution tracking (pCSD).
Results All three tractography algorithms could localize the core of the corticospinal tract
with good agreement. The pCSD-tracking algorithm was more sensitive in revealing the
anatomically most realistic fiber distribution and a proportion of fibers traversing
a solid part of the tumor. Intraoperative stimulation confirmed these fibers close
to the tumor. As a result, only a subtotal resection was performed, preventing postoperative
sensorimotor deficits.
Conclusion Although, all tractography algorithms successfully identified the core of the corticospinal
pathway, deterministic DTI-tractography, as widely used in clinical neuronavigation
software, only insufficiently visualized critical fibers here. We believe these results
argue for a stronger consideration of advanced tractography approaches in neurosurgical
planning.
Keywords
presurgical planning - DTI tractography - contrained spherical deconvolution