Probing brain connectivity by combined analysis of diffusion MRI tractography and electrocorticography

Electrocorticography (ECoG) allows for measurement of task-related local field potentials directly from cortex in neurosurgical patients. Diffusion tensor imaging (DTI) tractography is an MRI technique that allows for reconstruction of brain white matter tracts, which can be used to infer structural connectivity. This paper reports a novel merger of these two modalities. A processing stream is described in which fiber tracts near intracranial macroelectrodes showing task-related functional responses are isolated to explore structural networks related to working memory maintenance. Results show that ECoG-constrained tractography is useful for revealing structural connectivity patterns related to spatially- and temporally-specific functional responses.