To compare regional cerebellar microstructure, as measured by diffusion tensor imaging (DTI), between preterm infants at term-equivalent age and healthy term-born control neonates, and to explore associations between DTI findings and clinical risk factors.

In this case-control study, DTI studies were performed in 73 premature infants born ≤32 weeks and ≤1500 g birth weight and 73 full-term-born controls from healthy pregnancies. Using a region of interest approach, fractional anisotropy (FA) and mean diffusivity (MD) were extracted in 7 cerebellar regions including the anterior vermis, the right/left superior cerebellar peduncles, the middle cerebellar peduncle, and the dentate nuclei. To validate further our DTI measurements, we measured FA and MD in the genu of the corpus callosum and splenium. FA and MD were compared between groups using analyses of multiple linear regression models.

Preterm infants at term-equivalent age presented with higher FA in the dentate nuclei (<.001) and middle cerebellar peduncle (.028), and lower MD in the vermis (.023) compared with controls. Conversely, preterm infants showed reduced FA and increased MD in both the genu of the corpus callosum and splenium (P < .001). Independent risk factors associated with altered FA and MD in the cerebellum included low Apgar score, supratentorial injury, compromised cardiorespiratory function, and surgery for necrotizing enterocolitis and patent ductus arteriosus.

This DTI study provides evidence that complications of premature birth are associated with altered cerebellar microstructural organization when compared with term-born control infants.