title: Evaluation of amygdala pathology using (11)C-methionine positron emission tomography/computed tomography in patients with temporal lobe epilepsy and amygdala enlargement.
abstract: OBJECTIVE
  The association between amygdala enlargement (AE) and temporal lobe epilepsy (TLE) has increasingly been reported. However, the pathology of AE remains poorly understood. The purpose of this study was to explore AE pathology using (11)C-methionine (Met) positron emission tomography (PET)/computed tomography (CT) in patients who have TLE with AE.
  
  
  METHODS
  Twenty-six TLE patients with AE and 18 TLE patients without AE underwent (11)C-Met PET/CT and magnetic resonance imaging (MRI). (11)C-Met uptake in amygdala was evaluated by both visual inspection and semi-quantitative measurement. MRI was assessed visually and semi-quantitatively for AE. Laterality index (LI) was obtained by comparing the amygdala volumes of ipsilateral and contralateral sides. The clinical course and histopathological findings of all patients were also analyzed.
  
  
  RESULTS
  On (11)C-Met PET/CT images, visual examination detected increased uptake in the enlarged amygdala in 7 of 26 (27%) TLE patients with AE, and the results were confirmed by semi-quantitative analysis. Among six TLE patients with AE who underwent surgery, histopathology revealed neoplasms (low grade astrocytoma and gangliocytoma) in two patients and focal cortical dysplasia in one patient with increased (11)C-Met uptake, but non-neoplastic lesions (focal cortical dysplasia, vacuolar degeneration, and hamartoma) in all three patients with no increased (11)C-Met uptake. On MRI, volume of the affected amygdala was significantly larger compared to the contralateral amygdala. LI was significantly higher in the group with AE than in the group without AE.
  
  
  CONCLUSIONS
  This study revealed that some TLE patients with AE showed increased (11)C-Met uptake in the enlarged amygdala. (11)C-Met PET/CT is potentially useful for the evaluation of AE pathology, and may provide beneficial information for appropriate decision-making.
authors.affiliation: Department of Radiology, National Center of Neurology and Psychiatry, Japan; Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Japan. Electronic address: daichisone@gmail.com.
authors.forename: Daichi
authors.initials: D
authors.lastname: Sone
authors.affiliation: Department of Radiology, National Center of Neurology and Psychiatry, Japan. Electronic address: itoukimiteru@yahoo.co.jp.
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Neuropsychiatry, The University of Tokyo Hospital, Japan. Electronic address: taniguchi-jes@umin.ac.jp.
authors.forename: Go
authors.initials: G
authors.lastname: Taniguchi
authors.affiliation: Department of Psychiatry, National Center of Neurology and Psychiatry, Japan. Electronic address: ymurata@ncnp.go.jp.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Murata
authors.affiliation: Department of Radiology, National Center of Neurology and Psychiatry, Japan; Department of Neuroradiology, Tokyo Metropolitan Neurological Hospital, Japan. Electronic address: nakatay-tky@umin.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakata
authors.affiliation: Department of Psychiatry, National Center of Neurology and Psychiatry, Japan. Electronic address: wata-yt@ncnp.go.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, National Center of Neurology and Psychiatry, Japan. Electronic address: okazakim@ncnp.go.jp.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Okazaki
authors.affiliation: Department of Radiology, National Center of Neurology and Psychiatry, Japan. Electronic address: snoriko@ncnp.go.jp.
authors.forename: Noriko
authors.initials: N
authors.lastname: Sato
authors.affiliation: Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Japan. Electronic address: matsudah@ncnp.go.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
authors.affiliation: Department of Psychiatry, National Center of Neurology and Psychiatry, Japan. Electronic address: wata2ms@gmail.com.
authors.forename: Masako
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000679:Amygdala / Q000000981:diagnostic imaging* / Q000473:pathology*; D000927:Anticonvulsants / Q000627:therapeutic use; D002247:Carbon Isotopes / Q000493:pharmacokinetics*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008715:Methionine / Q000493:pharmacokinetics*; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D000927:Anticonvulsants; D002247:Carbon Isotopes; D008715:Methionine
keywords: (11)C-methionine; Amygdala enlargement; Brain neoplasms; PET; PET/CT; Temporal lobe epilepsy