title: Multimodality imaging for improved detection of epileptogenic foci in tuberous sclerosis complex.
abstract: OBJECTIVE
  Using interictal alpha-[11C]methyl-l-tryptophan ([11C]AMT) PET scan, the authors have undertaken a quantitative analysis of all tubers visible on MRI or 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) PET, to determine the relationship between [11C]AMT uptake and epileptic activity on EEG.
  
  
  BACKGROUND
  Tuberous sclerosis complex (TSC) is an autosomal dominant disorder, often associated with cortical tubers and intractable epilepsy. The authors have shown previously that [11C]AMT PET scans show high tracer uptake in some epileptogenic tubers and low uptake in the remaining tubers.
  
  
  METHODS
  Eighteen children, age 7 months to 16 years, were studied. Patients underwent video-EEG monitoring, PET scans of [11C]AMT and [18F]FDG, and T2-weighted or fluid-attenuated inversion recovery (FLAIR) MRI. [11C]AMT uptake values were measured in 258 cortical tubers delineated with coregistered MRI or [18F]FDG scans. Uptake ratios were calculated between the [11C]AMT uptake in tubers and those for normal cortex (tuber/normal cortex). Using the region of epileptiform activity, the authors performed receiver operator characteristics (ROC) analysis and determined the optimal uptake ratio for detecting presumed epileptogenic tubers.
  
  
  RESULTS
  Tuber uptake ratios ranged from 0.6 to 2.0. Tuber uptake ratios in the epileptic lobes were higher than those in the nonepileptic lobes (p < 0.0001). All 15 patients with focal seizure activity showed one or more lesions with uptake ratio above 0.98 in the epileptic lobe. ROC analysis showed that a tuber uptake ratio of 0.98 resulted in a specificity of 0.91.
  
  
  CONCLUSIONS
  Cortical tubers with [11C]AMT uptake greater than or equal to normal cortex are significantly related to epileptiform activity in that lobe. Together, interictal [11C]AMT PET and FLAIR MRI improve the detection of potentially epileptogenic tubers in patients with TSC being evaluated for epilepsy surgery.
authors.affiliation: Department of Pediatrics, Children's Hospital of Michigan and Detroit Medical Center, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: E
authors.initials: E
authors.lastname: Asano
authors.forename: D C
authors.initials: DC
authors.lastname: Chugani
authors.forename: O
authors.initials: O
authors.lastname: Muzik
authors.forename: C
authors.initials: C
authors.lastname: Shen
authors.forename: C
authors.initials: C
authors.lastname: Juhász
authors.forename: J
authors.initials: J
authors.lastname: Janisse
authors.forename: J
authors.initials: J
authors.lastname: Ager
authors.forename: A
authors.initials: A
authors.lastname: Canady
authors.forename: J R
authors.initials: JR
authors.lastname: Shah
authors.forename: A K
authors.initials: AK
authors.lastname: Shah
authors.forename: C
authors.initials: C
authors.lastname: Watson
authors.forename: H T
authors.initials: HT
authors.lastname: Chugani
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations / Q000235:genetics; D025063:Chromosome Disorders; D004827:Epilepsy / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005799:Genes, Dominant / Q000235:genetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D014055:Tomography, Emission-Computed; D014402:Tuberous Sclerosis / Q000175:diagnosis* / Q000235:genetics
chemical_list: D001786:Blood Glucose