A combined PET/MR scanner with simultaneous acquisition permits simultaneous imaging of physiologic & pathophysiologic processes and provides both anatomical & functional information on the same subject at the same time. It allows direct correlations of PET data with MR-detected patterns of neural synchrony in both grey and white matters; e.g. resting-state fMRI, diffusional kurtosis imaging, and MRS. This multi-modal analysis will facilitate the identification of an optimal biomarker. F-18-fluorodeoxyglucose (FDG) PET can often detect interictal seizure foci as areas of focally reduced regional cerebral metabolic rate for glucose.¹ Focal cortical abnormalities of neuronal architecture are often associated with interictal hypo-metabolism on FDG-PET scans.^2,3 FDG-PET may also help to assess the integrity of the regions remote from focal abnormalities.⁴ However, FDG-PET scans are routinely acquired as a single static scan after a period of uptake time. We and others have previously shown that the dynamic rate of FDG uptake in lesions is varied and different from that in normal tissues.⁵ Here we report our study to compare dynamic SUV and cortical thickness between controls (HC) and epilepsy patients (Ep) using simultaneous PET/MR.Subjects (11 HC and 27 Ep) were imaged on a combined PET/MR scanner (Biograph mMR, Siemens). After FDG injection, dynamic PET scans and simultaneous MR imaging (including T1, T2 and other sequences) were acquired for ~90 minutes. Dixon sequence was acquired for attenuation correction. PET data were reconstructed using the e7 tools provided by Siemens. Two methods for pre- and post-data processing were compared; Method A using FSL and Mango; Method B using Freesurfer and SPM. Over 100 masks (ROIs), including left and right, for cortical and subcortical regions were generated. Statistical analyses on mean SUV derived from the entire study (SUVmean_all) and meanSUV derived from the last three frames (SUVmean_late) were compared between groups. Cortical thickness values derived from Freesurfer were also compared between groups. Dynamic time-activity curves for specific ROIs for patients vs. controls were examined.Based on Mann-Whitney U tests, SUVmean_late values showed significant differences between groups for most ROIs, while no difference was seen with SUVmean_all. Temporal_Mid_tempocci consistently showed significant difference when normalized SUV values were compared (p<0.01, by individual subject’s mean cortical, white matter or global brain). Significant cortical thinning (Epi vs. HC) was detected bilaterally (left, right) within localized regions, such as precentral (p=0.017, 0.012) and superiorfrontal (p=0.016, 0.001). Binary logistic regression indicated that both SUVmean_late and cortical thickness were independent predictors for epilepsy. Time-activity curves for specific ROIs showed significant difference in the rate of FDG uptake for patients vs. controls. Our results suggest that 1) simultaneous PET/MR imaging provides a useful imaging tool to identify regional abnormalities; 2) more information can be rendered from dynamic PET data; 3) SUVmean_late and cortical thickness are independent biomarkers for epilepsy. In general, Freesurfer and SPM are more robust in orientation and segmentation than FSL.