title: Are there any gender differences in the hippocampus volume after head-size correction? A volumetric and voxel-based morphometric study.
abstract: Previous findings on normal sexual dimorphism in hippocampal volume have not always been consistent. This study investigated gender differences in hippocampal volume using different head-size correction strategies. T1-weighted MR images were collected in 99 healthy, Caucasian, university students (66 female subjects; mean age: 23.1 ± 2.3, range: 19-31 years). Sexual dimorphism in hippocampus was investigated by automated MRI volumetry and voxel-based morphometry (VBM) using both general linear model (GLM) and proportion head-size correction strategies. Absolute hippocampal volumes were larger in men than women. After adjusting for head-size, the proportion method indicated larger hippocampi in women than men, while no gender differences were found using the GLM approach. Investigating absolute hippocampal volumes in 15 head-size matched pairs of males and females indicated no gender differences. We suggest that there is no sexual dimorphism in hippocampal size and the apparent gender differences found by the proportion method may have more to do with head-size than with sex. The GLM and proportion head-size correction strategies are not interchangeable and may yield different results. The importance of the present findings is mostly related to scientific reproducibility across MRI volumetry or VBM studies.
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Pecs Diagnostic Centre, Ret u. 2, 7623 Pecs, Hungary. Electronic address: petzinger.gabor@gmail.com.
authors.forename: Gabor
authors.initials: G
authors.lastname: Perlaki
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Pecs Diagnostic Centre, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Orsi
authors.affiliation: Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Eniko
authors.initials: E
authors.lastname: Plozer
authors.affiliation: Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Anna
authors.initials: A
authors.lastname: Altbacker
authors.affiliation: Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Darnai
authors.affiliation: Pecs Diagnostic Centre, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Szilvia Anett
authors.initials: SA
authors.lastname: Nagy
authors.affiliation: Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Reka
authors.initials: R
authors.lastname: Horvath
authors.affiliation: Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary; Department of Neurosurgery, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Arnold
authors.initials: A
authors.lastname: Toth
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Department of Neurosurgery, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Tamas
authors.initials: T
authors.lastname: Doczi
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Norbert
authors.initials: N
authors.lastname: Kovacs
authors.affiliation: Pecs Diagnostic Centre, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Peter
authors.initials: P
authors.lastname: Bogner
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Department of Neurosurgery, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Schwarcz
authors.affiliation: MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, 7623 Pecs, Hungary; Department of Neurology, University of Pecs, Ret u. 2, 7623 Pecs, Hungary.
authors.forename: Jozsef
authors.initials: J
authors.lastname: Janszky
mesh_terms: D000328:Adult; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D012727:Sex Characteristics; D055815:Young Adult
keywords: Gender difference; Head-size correction; Hippocampus; MRI; VBM; Volumetry