Multi-modal imaging in epilepsy: SPECT and PET.

SPECT and PET play a complementary role in the presurgical evaluation of patients with refractory epilepsy. Perfusion SPECT can identify the ictal onset zone and PET can delineate the functional deficit zone. Both modalities have a role in localization and characterization of the epileptic focus and can help in the guidance of invasive EEG and in detecting subtle lesions on MRI.