Abstract: Objective To demonstrate the location of clinically eloquent white matter tracts with respect to cerebral tumors using diffusion tensor tractography (DTT) and to determine the role of this technique in neurosurgical planning and postoperative assessment.Methods Sixteen patients with pathologically proved brain tumors underwent diffusion tensor imaging prior to tumor excision. By using tractography software package, the vital white matter tracts (include pyramidal tract, corpus callosum and optic radiation) were reconstructed and the exact locations of the lesion with respect to clinically eloquent white matter tracts were observed in every patient. Then reasonable surgical plan was determined. After operation, the diffusion tensor imaging was performed again and associated white matter tracts were evaluated to investigate the effect of these structures by surgery.Results The relationships between tumors and white matter tracts could be divided into three types: simple displacement, displacement with disruption and simple disruption. Pyramidal tract was involved in 12 cases, 1 case was simple displacement, 9 cases were displacement with disruption and other 2 cases were simple disruption without any improvement. Corpus callosum was involved in 7 cases, three of them were displacement with disruption which reducing displacement after operation and other 4 cases were simple disruption without any improvement. Optic radiation was involved in 3 cases, all were simple displacement with reducing of displacement after operation.Conclusion Visualization of the exact location of vital white matter tracts with respect to cerebral tumors can be shown before operation by DTT.

Key words: tractography, diffusion tensor tractography, magnetic resonance tractography, brain tumor