title: Amygdalar and hippocampal volumetry in control participants: differences regarding handedness.
abstract: OBJECTIVE
  Amygdalar and hippocampal volume measurements indicate a right-greater-than-left asymmetry for right-handed normal participants in most studies. The purpose of this study was to compare amygdalar and hippocampal volume ratios between right- and left-handed participants.
  
  
  METHODS
  Amygdalar and hippocampal volume measurements were performed in 34 (20 right-handed and 14 left-handed) normal participants. All participants completed a 10-item handedness questionnaire. The MR imaging sequence was a 3D T1-weighted gradient-echo acquisition of the whole brain (24/6 [TR/TE]; flip angle, 25 degrees). MR images were spatially normalized, and volumes were painted with a 1.0-mm(3) resolution cursor on an SGI workstation.
  
  
  RESULTS
  In right-handed participants, the amygdala and hippocampus (P <.001 for both) were significantly larger on the right side than on the left. The left-handed group did not show a significant difference between right- and left-sided structures. Right-to-left volume ratios differed significantly between right- and left-handed participants for both amygdalar (P <.02) and hippocampal (P <.01) structures. Gender did not affect right-to-left amygdalar and hippocampal volume ratios in right- or left-handed participants.
  
  
  CONCLUSIONS
  Handedness, but not gender, seems to affect right-to-left amygdalar and hippocampal volume ratios.
authors.affiliation: Division of Neurology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78284, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Szabo
authors.forename: J
authors.initials: J
authors.lastname: Xiong
authors.forename: J L
authors.initials: JL
authors.lastname: Lancaster
authors.forename: L
authors.initials: L
authors.lastname: Rainey
authors.forename: P
authors.initials: P
authors.lastname: Fox
mesh_terms: D000328:Adult; D000679:Amygdala / Q000033:anatomy & histology*; D002508:Cephalometry; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D012016:Reference Values