AUTHOR=Yang Qinzhu , Cai Shuxiu , Chen Guojing , Yu Xiaxia , Cattell Renee F. , Raviv Tammy Riklin , Huang Chuan , Zhang Nu , Gao Yi 

TITLE=Fine scale hippocampus morphology variation cross 552 healthy subjects from age 20 to 80

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 17 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1162096

DOI=10.3389/fnins.2023.1162096

ISSN=1662-453X

ABSTRACT=It is well known that the landscape of the cerebral cortex varies in a person's life span: the surface is smooth at birth, bumpier (deeper sulci and thicker gyri) in the middle age, and thinner in seniors. In this work, similar phenomenon was observed on the hippocampus. While it has been believed that fine-scale morphology of the hippocampus can be extracted only with high field scanners (7T, 9.4T), recent studies show that regular 3T MR scanners can be sufficient for this purpose. This finding opens the door for the fine hippocampal morphometry study on large amount of clinical data. In particular, a characteristic bumpy and subtle feature on the inferior aspect of hippocampus, which we refer to as hippocampal dentation, present a dramatic degree of variability between individuals from very smooth to highly dentated. In this report, we propose a combined method joining deep learning and sub-pixel level set evolution, and efficiently obtain fine-scale hippocampal segmentation on 552 healthy subjects. Then, through nonlinear dentation extraction and fitting, we reveal that the bumpiness of the inferior surface of human hippocampus has a clear temporal trend. It is the bumpiest between 40-50 years old. Such an observation should be aligned with the neuro-developmental and aging stages.