In the pre-surgical evaluation of epilepsy patients, different functional investigations can be combined and co-registered to computerised image processing methods to enhance their diagnostic value. A method for subtraction of interictal from ictal SPECT is used, and the result is co-registered to MR, demonstrating the change in blood flow during seizure in the patient's MR-image. The level of significance is calculated and a statistical map is produced. Recent methods for EEG source localization use the MR-image to create a model of the head, producing more accurate solutions. Cases are demonstrated illustrating results concordant with these independent methods.