Assessment of brain maturation in the preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN)

Purpose: To assess the brain maturation of preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN).

Materials and methods: Conventional magnetic resonance imaging (MRI), DTI and ESWAN were performed in 60 preterm infants and 21 term controls. 60 preterm infants were subgrouped to two groups according to the age at imaging: before and at term-equivalent age (TEA). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) map from DTI, T2 and R2 maps from ESWAN were post-processed at an off-line workstation. The values of FA, ADC, T2 and R2 from the posterior limb of internal capsule (PLIC), frontal white matter (FWM), occipital white matter (OWM) and lentiform nuclei (LN) were determined. These parameters were compared between preterm and term infants. Correlations of DTI and ESWAN parameters with the gestational age, postmenstrual age and postnatal age were analyzed.

Results: ADCs of FWM, OWM and LN, and T2 values of the PLIC and LN were higher in the preterm infants at TEA compared with the term controls. The correlations were existed between the postmenstrual age and the values of FA, ADC, T2, R2 from the PLIC, values of ADC, T2, R2 from the LN, T2 value from the OWM. The correlations were also found between the postnatal age and the values of FA, ADC, T2 from the PLIC, and T2 value from the LN.

Conclusion: The maturity of preterm brain around TEA was different from that of term controls and appeared to be independent of the prematurity at birth. T2 was one of valuable indices to evaluate brain maturation in preterm infants.