title: Comparison of hippocampal volumetry at 1.5 tesla and at 3 tesla.
abstract: OBJECTIVE
  Hippocampal volumetry using magnetic resonance imaging (MRI) is a common clinical study in epilepsy patients. Most clinical MR scans operate at 1.5 tesla (T); however, there is increasing use of scanners of a higher field strength. We analyzed whether control data of hippocampal volumes can be used across different field-strength scanners.
  
  
  METHODS
  We studied eight adult healthy controls twice at both 1.5 and 3 T. Bilateral hippocampal volumes were measured by manual outlining. Measurement error was analyzed based on the variability between two measurements at the same field strength, and intrascanner variability was analyzed based on the difference between measurements obtained at 1.5 and at 3 T.
  
  
  RESULTS
  The measurement error was 4.0% (+/-3.1) at 1.5 T, and 3.4% (+/-2.5) at 3 T. The intrascanner variability between measurements at 1.5 and at 3 T was 6% (+/-3.9). The intrascanner variability was not different from the measurement error.
  
  
  CONCLUSIONS
  Control hippocampal volume measurements obtained at 1.5 and at 3 T were not different.
authors.affiliation: Brain Research Institute, Austin and Repatriation Medical Center, Melbourne, Australia.
authors.forename: R S
authors.initials: RS
authors.lastname: Briellmann
authors.forename: A
authors.initials: A
authors.lastname: Syngeniotis
authors.forename: G D
authors.initials: GD
authors.lastname: Jackson
mesh_terms: D000328:Adult; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D015203:Reproducibility of Results