Volumetric Asymmetry and Differential Aging Effect of the Human Caudate Nucleus in Normal Individuals: A Prospective MR Imaging Study

PURPOSE The purpose of this study was to examine interhemispheric asymmetry in volume of the caudate nucleus and its age dependency. METHODS High-resolution T1-weighted brain magnetic resonance (MR) images were obtained for each subject using a 3-dimensional fast field-echo pulse sequence. The volumes of the bilateral caudate nuclei on MR images were measured using an automated method. Right-to-left comparison was made using paired t-test. Age-related change of right-to-left volume ratio (R/L ratio) was examined using Pearson's correlation coefficient. RESULTS Fifty healthy right-handed Japanese male subjects (age 12 to 67 years, mean 39.6 years) were involved in this study. The volume of right caudate nucleus was larger than the left in 48 of 50 subjects (P < .001). R/L ratio increased with age (r = .420, P < .01). CONCLUSIONS Our results confirmed the rightward volumetric asymmetry of caudate nucleus in right-handed individuals, and revealed that this asymmetry becomes notable with age.