Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy

BACKGROUND AN PURPOSE: MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical local ization of epileptic foci. However, comparative study of these imaging meth ods for cases of neocortical epilepsy has been limited, The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci. METHODS: We studied 117 consecutive patients who underwent surgery for intr actable neocortical epilepsy, The pathologic substrates were neuronal migra tion disorder (n = 77), tumor (n = 15), and others (n = 25), MR imaging was compared retrospectively with F-18-fluorodeoxyglucose PEI and ictal techne tium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci, The pathologic findings were us ed as the standard of reference. RESULTS: Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 3 8% concordance rate among the three methods. PET was most sensitive (71-100 %) in detecting all substrates. MR imaging was as sensitive (100%) as PET i n detecting turner but was least sensitive (48.1%) in detecting neuronal mi gration disorder, Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for tho se without imaging abnormalities (P < .05). CONCLUSION: PET and ictal SPECT were overall more sensitive than was MR ima ging, despite the low concordance rate and variable sensitivity depending o n substrates, The detection of abnormalities by MR imaging was associated w ith good outcome, PET or ictal SPECT can be well used as complementary tool s, particularly hn cases of negative MR imaging findings.