Value of PET/MRI registration in prediction of surgical outcome of nonlesional temporal lobe epilepsy

Objective Compared to 18F-FDG PET-CT,to validate the use of interictal 18FFDG PET/MRI registration in the location of epilepsitic lesions and prediction of surgical outcome.Methods Forty-five patients of intractable temporal lobe epilepsy were recruited retrospectively.All patients underwent persurgical evaluation included clinical symptoms,long-term video electroencephalogram(VEEG),PET-CT,and MRI.They were followed-up at least 2 years after surgery and evaluated with Engel's classification.Both volumes of PET and 3D MRI were coregistered into PET/MRI using Siemens 3D volume software to study the relationship between the metabolic patterns of PET/MRI and surgical curative effects.Results The postoperative effect demonstrated that among 37 patients with limited temporal low metabolism detected by PET/MRI,29 cases reached to grade Ⅰ or Ⅱ effects and 22 cases (76％) showed the low metabolism restricted to mesial temporal lobe,while 8 cases reached Engel's grade Ⅲ or Ⅳ and the range of low mechanism in 6 cases beyond the anterior temporal lobe.The significant difference (P ＜ 0.05) was found between the postoperative effects with different metabolic areas by Chi square.Conclusions The temporal hypometabolism over the medial and anterior part of temporal region and the temporal pole might be a better predictor for postoperative seizure control.18F-FDG PET/MRI registration was a more accurate imaging variant in the pediatrion for nonlesional patients.The patterns of PET/MRI metabolic images could further help the surgeon to select patients,plan operation and predict therapy. Key words: Nonlesional temporal lobe epilepsy;  VEEG;  PET-CT;  PET-MRI registration