Serial diffusion tensor images during infancy and their relationship to neuromotor outcomes in preterm infants.

BACKGROUND

Even preterm infants with normal magnetic resonance imaging (MRI) results are at greater risk for neuromotor dysfunction.

OBJECTIVES

Our aim was to compare serial diffusion tensor imaging (DTI) data from preterm infants without apparent brain abnormalities on magnetic resonance imaging with those from term controls and to investigate the white matter (WM) region associated with neuromotor outcomes.

METHODS

We obtained serial DTIs from 21 preterm infants at term-equivalent age (TEA) and 1 year of corrected age. As controls, 15 term neonates and 20 newly recruited term infants aged 1 year underwent DTI. Preterm and term infants at 1 year of age were assessed with the Bayley Scales of Infant Development, second edition. Tract-based spatial statistics and regions of interest were used for analysis.

RESULTS

At TEA, the entire WM development was delayed in the preterm infants compared with the term controls, but at 1 year of age, the WM development, except for that of the corpus callosum (CC), had reached the development level of the term controls. The psychomotor developmental index was positively correlated with the fractional anisotropy (FA) in the CC (particularly in the body and splenium) at 1 year of age after correcting for gestational age, chronic lung disease, and postnatal infection.

CONCLUSIONS

The CC of the preterm infants was consistently underdeveloped compared with that of the term controls. The FA in the CC, particularly in the body and splenium at 1 year of age, well reflected the degree of motor function in infants without apparent brain abnormalities.