RT Journal Article
SR Electronic
T1 Joint analysis of area and thickness as a replacement for the analysis of cortical volume
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 074666
DO 10.1101/074666
A1 Anderson M. Winkler
A1 Douglas N. Greve
A1 Knut J. Bjuland
A1 Thomas E. Nichols
A1 Mert R. Sabuncu
A1 Asta K. Håberg
A1 Jon Skranes
A1 Lars M. Rimol
YR 2017
UL http://biorxiv.org/content/early/2017/10/24/074666.abstract
AB Cortical surface area is an increasingly used brain morphology metric that is ontogenetically and phylogenetically distinct from cortical thickness and offers a separate index of neurodevelopment and disease. However, the various existing methods for assessment of cortical surface area from magnetic resonance images have never been systematically compared. We show that the surface area method implemented in FreeSurfer corresponds closely to the exact, but computationally more demanding, mass-conservative (pyc-nophylactic) method, provided that images are smoothed. Thus, the data produced by this method can be interpreted as estimates of cortical surface area, as opposed to areal expansion. In addition, focusing on the joint analysis of thickness and area, we compare an improved, analytic method for measuring cortical volume to a permutation based non-parametric combination (NPC) method. We use the methods to analyse area, thickness and volume in young adults born preterm with very low birth weight, and show that NPC analysis is a more sensitive option for studying joint effects on area and thickness, giving equal weight to variation in both of these two morphological features.