title: Voxel- and ROI-based statistical analyses of PET parameters for guidance in the surgical treatment of intractable mesial temporal lobe epilepsy.
abstract: OBJECTIVE
  Positron emission tomography (PET) can be used to locate epileptic foci in patients with mesial temporal lobe epilepsy (MTLE) by measuring multiple parameters of the brain. We investigated a series of patients with MTLE using PET measurements of three parameters: the cerebral blood flow measured with [15 O] H2O, the uptake of [18F] fluorodeoxyglucose (FDG), an index of the cerebral metabolism rate of glucose, and the distribution volume (DV) of [11C] flumazenil (FMZ), an index of the binding potential of central benzodiazepine receptor. We compared predictive values obtained from two methods: a voxel-based statistical analysis using statistical parametric mapping (SPM) and an asymmetry index obtained by placing regions of interest (ROIs) on PET images.
  
  
  METHODS
  Preoperative PET data of 11 patients with surgically confirmed MTLE were retrospectively examined. In the voxel-based analysis, the PET data were analyzed using SPM99 by statistically comparing the voxel values of PET parameters between individual patients and the mean values of 12 normal volunteers. Voxels with values significantly lower than the normal control values were mapped on a standard brain atlas. In the ROI-based analysis, the asymmetry index was calculated to depict ROIs with abnormally decreased values when compared with the contralateral side.
  
  
  RESULTS
  (1) Statistical parametric mapping and ROI analyses of the FDG uptake correctly determined epileptic temporal lobe in 73% and 82%, respectively. (2) The decreased DV of FMZ depicted by SPM revealed the mesial temporal pathology in 91%.
  
  
  CONCLUSIONS
  Positron emission tomography measurement of FDG uptake was most sensitive in detecting the side of the epileptic focus. On the other hand, SPM analysis of the DV of FMZ was the most sensitive method for delineating the actual epileptic focus.
authors.affiliation: Department of Neurosurgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Ohta
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nariai
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mishina
authors.forename: Michio
authors.initials: M
authors.lastname: Senda
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Hirakawa
authors.forename: Kikuo
authors.initials: K
authors.lastname: Ohno
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D003198:Computer Simulation; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18