Morphometric evaluation of the human hippocampus and hippocampal subfield volume characteristics by VolBrain/HIPS

Abstract

In the literature, research often utilizes digital segmentation methods like VolBrain, aiding in anatomical understanding. However, racial and population-specific differences remain unclear but may be important for clinical interpretation. We seek to enhance clinical perspectives by providing normative data and insights into hippocampal morphology, potentially advancing diagnostic and prognostic methodologies in neurological disorders. We think that it is necessary to discuss the reported asymmetry data by VolBrain. There might be inaccuracies or inconsistencies in how asymmetry is measured and reported. MRIs of the 138 healthy individuals (66 females, 72 males) were included. The VolBrain-HIPS pipeline was preferred for automatic segmentation. Alternative methods were recruited, including the total hippocampal volume for the adjustment of the volumetric data. Asymmetry index was accepted as the indicator of the magnitude of the asymmetry and negative asymmetry index data was positivized. Gender and side comparisons of the hippocampal data were presented not only for absolute measurement but also for the adjusted volumetric data. Comparisons for the magnitude of the asymmetry were carried out as well as the regression modeling based on age and gender. Hippocampus-adjusted volume information should also be considered when analyzing VolBrain data and making clinical or anatomical decisions. The asymmetry data produced by VolBrain should be considered as a magnitude scale of the asymmetry in individuals with right or left dominant hippocampus or hippocampus subfield. Alternative significant regression models were introduced to observe how the volumetric numerical composition of the hippocampus subfields changes with age.