MRI remains the imaging modality of choice for anatomic abnormalities. High-field magnets (e.g. 3.0 T) are increasingly used during pre-surgical evaluation of drug-resistant focal epilepsy. Abnormalities are identified in 1/4th of normal 1.5 T scans though with surface coils up to 65% (especially cortical dysplasia) may yield differences (1). DTI measures white mater integrity by measuring the directional magnitude of water diffusion in 3-dimensional space (fractional anisotropy: FA). A preferred direction of water diffusion is seen if white matter fascicles have structural coherence (high FA) but low FA if poor structural organization allows random water diffusivity. Both the distance from Meyer’s loop to the tip of the temporal lobe and extent of the resection predicts VFDs following temporal resection (2). DTI tractography of the optic radiations contained in the white matter tracts were left intact in our patient with a right amygdalo-hippocampectomy resulting in seizure-freedom without new VFD after surgery.
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