Hippocampal volumetry using automated segmentation on high-resolution three-dimensional magnetic resonance imaging in the adult Indian population

Background: The hippocampal volume (HV) reduces with normal aging and in certain neuropsychiatric diseases. An understanding of age and sex-related HV changes will help better comprehend volumetric changes in neuropsychiatric diseases. Aims and Objectives: The aim of the study is to evaluate age and sex-related variations in hippocampal volumetry on magnetic resonance imaging in the adult Indian population. Materials and Methods: Three-dimensional volumetric T1-weighted magnetization prepared rapid gradient-echo images of 192 adults (mean age 46.2±16.8 years) were analyzed using automated segmentation. The mean HV of both sides was compared between age groups in both sexes using a t-test. Pearson correlation was done to assess relationships between age and mean HV and asymmetry indices. Results: The mean HV in males was 3.31±0.44 mL and in females was 3.04±0.49 mL (P<0.0001). The mean right and left HV in males were 3.35±0.43 mL and 3.27±0.45 mL and in females were 3.07±0.51 mL and 3.00±0.48 mL, respectively (P=0.0001). Pearson correlation showed a weak inverse relationship between age and right and left HV in males (P=0.01038 and P=0.1679, respectively) and in females (P=0.013 and P=0.01665, respectively). There was a significantly small positive relationship between age and absolute asymmetry index in females (P=0.0288) but a non-significant negative relationship in males (P=0.6642). Conclusion: The mean HV, right HV, and left HV were significantly higher in males than in females. There was a slight age-related decline in right and left HV in both sexes. There was a small age-associated increase in absolute asymmetry in females, not seen in males.