Comparative Analysis of MR Imaging, Positron Emission Tomography, and Ictal Single-photon Emission CT in Patients with Neocortical Epilepsy
Sung-Il Hwanga,
Jae Hyoung Kima,
Sun Won Parka,
Moon Hee Hana,
In Kyu Yua,
Sang Hyun Leea,
Dong Soo Leea,
Sang Kun Leea,
Chun-Kee Chunga and
Kee-Hyun Chang
,a
a From the Departments of Radiology (S.-I.H., S.W. P., M.H.H., I.K.Y., S.H.L., K.-H.C.), Nuclear Medicine (D.S.L.), Neurology (S.K.L.), and Neurosurgery (C-K.C.), Seoul National University College of Medicine, Seoul; the Institute of Radiation Medicine SNUMRC (M.H.H., K.-H.C.), Seoul; and the Department of Radiology (J.H.K.), Gyeongsang National University College of Medicine, Chinju, Korea.
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FIG 1. Concordance of the results among MR imaging, PET, and ictal SPECT findings for a 36-year-old man with left neocortical temporal lobe epilepsy.
A, Oblique coronal fast spin-echo T2-weighted (6000/90) MR image shows a well-defined focal high signal intensity in the left inferior temporal lobe (arrow).
B, FDG PET scan shows hypometabolism in the left inferior temporal lobe (arrow).
C, Ictal SPECT scan shows focal hyperperfusion in the left inferior temporal lobe (arrow). Lesion-like increased uptake in the right frontotemporal lobe is due to asymmetrical reconstruction of the image. After anterior temporal lobectomy, the pathologic diagnosis was dysembryoplastic neuroepithelial tumor. Engel's outcome was class I
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FIG 2. False-negative MR imaging finding for a 24-year-old woman with left frontal lobe epilepsy.
A, Axial fast spin-echo T2-weighted (5000/100) MR image shows no diagnostic abnormality.
B, FDG PET scan shows diffuse hypometabolism in the left frontal and parietal cortices (arrows).
C, Ictal SPECT scan shows diffuse hyperperfusion in the same area as that shown in B (arrows). Invasive EEG study localized the epileptogenic focus in the left inferior frontal lobe. After neocortical resection, the pathologic diagnosis was cortical dysplasia. Engel's outcome was class I
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FIG 3. False-negative MR imaging and ictal SPECT findings for an 18-year-old female patient with left frontal lobe epilepsy.
A, Axial fast spin-echo T2-weighted (6000/90) MR image shows no diagnostic abnormality.
B, FDG PET scan shows focal hypometabolism in the left frontal cortex (arrows).
C, Ictal SPECT scan fails to show hyperperfusion in any area. Lesion-like increased uptake in the left basal ganglia is due to asymmetrical reconstruction of the image. Invasive EEG study detected ictal activity originating from the left frontal lobe. After neocortical resection, the pathologic diagnosis was microdysgenesis. Engel's outcome was class IV
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FIG 4. False-negative MR imaging and PET findings for a 25-year-old woman with right neocortical temporal lobe epilepsy.
A, Axial fast spin-echo T2-weighted (6000/90) MR image shows no focal abnormalities.
B, Axial FDG PET scan show no focal abnormalities.
C, Ictal SPECT scan shows somewhat diffuse hyperperfusion in the right frontotemporal cortices (arrows). Invasive EEG study detected ictal activity arising from the right temporoparietal area. After neocortical resection, the pathologic diagnosis was heterotopia. Engel's outcome was class I
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