title: Computer-assisted lateralization of unilateral temporal lobe epilepsy using Z-score parametric F-18 FDG PET images.
abstract: BACKGROUND
  To evaluate the use of unbiased computer-assisted lateralization of temporal lobe epilepsy (TLE) by z-score parametric PET imaging (ZPET).
  
  
  METHODS
  38 patients with histologically proven unilateral TLE due to pure hippocampal sclerosis, referred for pre-surgical PET evaluation of intractable seizure over a 5-year period, were included. The F-18 FDG images were oriented along temporal long axis and then transformed into ZPET images on a voxel by voxel basis. Multiple regions of interests (21 in total) were placed on cortical, subcortical and cerebellar structures on twenty-eight out of 38 patients with totally seizure-free (class I) outcome. Paired t-tests with Bonferroni correction were used to determine the location of the most asymmetric regions as variables for subsequent discriminant analysis of the entire group of the patients.
  
  
  RESULTS
  The computer program identified the anterior half of the temporal lobe (p < 0.0005) and thalami (p = 0.021) as the most asymmetric regions in TLE patients with Class I outcome. Discriminant analysis using z-scores from a total of 8 ROIs (in 4 pairs) on these structures correctly lateralized thirty-seven out of 38 (97%) patients (sensitivity = 94%; specificity = 100%). The only false localization came from a patient with equivocal z-scores on the temporal lobes and this patient turned out to have poor outcome.
  
  
  CONCLUSIONS
  The computer-assisted lateralization of TLE using ZPET provides an accurate, fast and objective way of seizure evaluation.
authors.affiliation: Nuclear Medicine, William Beaumont Hospital, Royal Oak, MI, USA. owong@beaumont.edu
authors.forename: Ching-Yee Oliver
authors.initials: CY
authors.lastname: Wong
authors.forename: James
authors.initials: J
authors.lastname: Gannon
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bong
authors.forename: Christiana O
authors.initials: CO
authors.lastname: Wong
authors.forename: Gopal B
authors.initials: GB
authors.lastname: Saha