Open AccessStatistical neuroanatomy of the human inferior frontal gyrus and probabilistic atlas in a standard stereotaxic space
Author(s) -
Hammers Alexander,
Chen ChiHua,
Lemieux Louis,
Allom Richard,
Vossos Spyridon,
Free Samantha L.,
Myers Ralph,
Brooks David J.,
Duncan John S.,
Koepp Matthias J.
Publication year - 2007
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20254
Subject(s) - inferior frontal gyrus , neuroanatomy , frontal lobe , brain size , limbic lobe , medicine , psychology , nuclear medicine , neuroscience , anatomy , magnetic resonance imaging , radiology , functional magnetic resonance imaging
Abstract We manually defined the inferior frontal gyrus (IFG) on high‐resolution MRIs in native space in 30 healthy subjects (15 female, median age 31 years; 15 male, median age 30 years), resulting in 30 individual atlases. Using standard software (SPM99), these were spatially transformed to a widely used stereotaxic space (MNI/ICBM 152) to create probabilistic maps. In native space, the total IFG volume was on average 5%, and the gray matter (GM) portion 12% larger in women (not significant). Expressed as a percentage of ipsilateral frontal lobe volume (i.e., correcting for brain size), the IFG was an average of 20%, and the GM portion of the IFG 27%, larger in women ( P < 0.005). Correcting for total lobar volume yielded the same result. No asymmetry was found in IFG volumes. There were significant positional differences between the right and left IFGs, with the right IFG being further lateral in both native and stereotaxic space. Variability was similar on the left and right, but more pronounced anteriorly and superiorly. We show differences in IFG volume, composition, and position between sexes and between hemispheres. Applications include probabilistic determination of location in group studies, automatic labeling of new scans, and detection of anatomical abnormalities in patients. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.