Article Figures & Data
Figures
- FIG 1.
Concordant FDG-PET and ASL findings. A patient with focal epilepsy localized to the left precentral gyrus on sEEG with concordant findings on both FDG-PET and ASL. A, T1-weighted structural imaging for anatomic reference without an abnormality in the left precentral gyrus (arrow). B, FDG-PET image demonstrates focally decreased uptake in the left precentral gyrus (arrow) and more mildly decreased uptake in the broader left frontal lobe. C, Associated low signal on ASL in the left precentral gyrus (arrow) and more mildly decreased uptake in the broader left frontal lobe.
- FIG 2.
Discordant FDG-PET and ASL findings. A patient with focal epilepsy localized to the left insula on sEEG with discordant findings on FDG-PET and ASL. A, T1-weighted structural imaging for anatomic reference without an abnormality in the right superior frontal gyrus (arrow). B, FDG-PET image demonstrates focally decreased uptake in the right superior frontal gyrus (arrow). C, ASL image with absence of a correspondingly low signal in the right superior frontal gyrus (arrow) but with apparent low signal overlying the left frontal lobe (chevron), which is of unclear clinical significance.
Tables
Epileptogenic Foci Recorded on sEEG/vEEG All Sites Temporal Extratemporal All sites 35 11 24 PET/MR imaging results FDG positive foci 27 14 13 FDG and ASL positive foci 20 10 10 FDG FDG and ASL Nam Test Statistic P Value All patients Sensitivity 0.64 (0.47–0.78) 0.52 (0.35–0.68) 2.00 .02 Specificity 0.50 (0.26–0.75) 0.75 (0.47–0.91) –1.73 .04 Accuracy 0.51 (0.36–0.66) 0.53 (0.38–0.68) Positive predictive value 0.59 (0.39–0.76) 0.75 (0.51–0.91) Negative predictive value 0.38 (0.15–0.65) 0.36 (0.18–0.57) Temporal epilepsy Sensitivity 0.83 (0.55–0.95) 0.75 (0.47–0.91) 1.0 .16 Extratemporal epilepsy Sensitivity 0.52 (0.32–0.72) 0.38 (0.21–0.59) 1.73 .04 ↵a Data are reported in the format of proportions (95% confidence intervals). Sensitivity and specificity were calculated separately from the subsets of patients with positive findings on EEG findings and negative findings on EEG, respectively. Accuracy, positive predictive value, and negative predictive value were calculated with the entire patient sample (ie, patients with both positive and negative EEG findings). The sensitivities for temporal and extratemporal epilepsy were calculated in those patients with positive EEG foci in each of these regions, respectively.
FDG Combined with ASL-Positive FDG Combined with ASL-Negative Totals FDG-only positive Observed: 20Expected: 12 Observed: 7Expected: 15 27 FDG-only negative Observed: 0 Expected: 8 Observed: 18Expected: 10 18 Totals 20 25 45 Cohen κ coefficient 0.70 (0.50– 0.89) P value <.01 ↵a Data are reported in format of κ (95% confidence interval).
