The Effects of Age, Gender and Head Size on the Cortical Thickness of Brain

Park, Yunyoung; Kim, Siekyeong

Abstract

OBJECTIVES
Standardization of head size is essential for the volume study. Cortical thickness analyses are increasingly being used in many fields of neuroscience. However, it is not established whether head size correction should be done for thickness study.
METHODS
Using the Open Access Series of Imaging Studies data, we determined cortical thickness of 316 cognitively normal participants aged 18-94 with FreeSurfer. The association between head size and cortical thickness of whole cortical mantle and in each lobe among age tertile groups was assessed. Estimated total intracranial volume (eTIV) was calculated for determining head size.
RESULTS
Across all participants, cortical thickness in whole brain except some areas in cingulate and insula decreased with aging. eTIV had positive correlation with the thickness of frontal, parietal, occipital and whole brain areas. However, the age effect was not shown in whole brain of the first tertile group and in cingulate areas of the third tertile group. eTIV had negative correlation with the thickness of cingulate in the third tertile group. Gender effects were shown in some areas in third tertile group, but it would be due to difference of head size.
CONCLUSIONS
These findings suggest that head size standardization might be done especially in older population and in studies of paralimbic areas.