Basal Ganglia Maturation in Neonates Using QSM and R2*: Nucleus-Specific, Time-Dependent Trajectories and Effects of Prematurity

OBJECTIVE: To delineate the developmental trajectories of basal ganglia nuclei in neonates using quantitative susceptibility mapping (QSM) and R2* imaging, and to dissect the respective contributions of gestational age (GA), postmenstrual age (PMA), and postnatal age (PNA) as well as the impact of prematurity. METHODS: 115 neonates (66 preterm, 49 term) underwent MRI at PMA 36-44.1 weeks. QSM and R2* were extracted from basal ganglia nuclei. Associations between imaging metrics and PMA, GA, and PNA were analyzed. Preterm-term comparisons and preterm subgroup analyses were performed. RESULTS: QSM and R2* values in the caudate nucleus (CN), globus pallidus (GP), and putamen (PUT) showed positive correlations with GA but negative correlations with PNA in all neonates and preterm neonates. CN R2* was negatively correlated with PMA in all neonates. PUT and GP R2* was positively correlated with PMA in all neonates. Compared with term neonates, preterm neonates demonstrated lower QSM and R2* in the CN, PUT, and GP. Among preterm neonates, those born at GA ≤ 34 weeks had significantly lower CN R2* than those born at 34-37 weeks. CONCLUSION: Basal ganglia maturation demonstrates nucleus-specific and time-dependent characteristics. Prematurity represents not a simple developmental delay but an alteration of the normative maturational tempo.