Normal ADC values at term equivalent age in the newborn: Comparison between term and very preterm infants

PurposeOnly limited studies have directly compared apparent diffusion coefficient (ADC) values at term-equivalent age (TEA) between normal term infants and very preterm infants. We hypothesized that regional ADC values at TEA would differ between preterm infants and term infants, even in the absence of MRI-detectable brain injury. The purpose of this study was to compare ADC values at TEA between term infants and preterm infants born at less than 32 weeks of gestation.Subjects and methodsThis retrospective study enrolled consecutive infants who underwent neonatal brain MRI over a 7-year period from 2016 to 2022. From this cohort, very preterm infants were selected after confirmation of normal MRI findings and normal neurodevelopmental outcomes. ADC values were measured at six predefined brain regions. ADC values were compared between term infants and preterm infants, and further subgroup analyses were performed among term, very preterm, and extremely preterm infants.ResultsADC values at the basal ganglia were significantly higher in preterm infants compared with term infants. No significant differences were observed at the other five brain regions. Subgroup analysis among term, very preterm, and extremely preterm infants demonstrated significant differences in basal ganglia ADC values, with both very preterm and extremely preterm infants showing higher ADC values than term infants.ConclusionADC values at the basal ganglia at TEA were significantly higher in preterm infants than in term infants, despite normal conventional MRI findings and favorable neurodevelopmental outcomes. These findings suggest region-specific differences in brain microstructural maturation associated with preterm birth.