Microstructural changes in white matter (WM) can be detected by Diffusion Tensor Imaging (DTI). This study tests the hypothesis that Fractional Anisotropy (FA) in the posterior limb of the internal capsule (PLIC), as measured directly on the FA-maps in preterm infants ATE is correlated to neuro-developmental outcome at two years corrected age.
Methods MRI at term was performed in 66 preterm infants (GA< 32wks), Using colour-coded DTI maps, FA-values were assessed in the PLIC. Regions of interest (ROI’s) were manually positioned in the PLIC bilaterally at the level of the foramen of Monro. FA-values from these ROI’s were assessed in relation to scores for cognition, fine and gross motor outcome measured with the Bayley Scales of Infant and Toddler Development (BSITD)-III. Correlations were corrected for clinical factors.
Results FA-values in the left PLIC were correlated with cognition (r=0,435, p<0.05), fine motor (r=0,335, p<0.05) and gross motor (r=0,337, p<0.05) outcome at two years corrected age. There was no such association for the right PLIC. After correction for gender, the correlation persisted only in boys. Postmenstrual age (PMA) and WMI were both significantly correlated with FA values in the left PLIC (resp r=0.253, p<0.05 and r= –0.368, p<0.05).
Conclusion FA-values measured by ROI-analysis ATE are significantly correlated with neurodevelopmental outcome at two years. This is in agreement with studies that used advanced post-processing techniques to measure diffusion parameters. These measurements in this study are easy to perform, reproducible and directly applicable on MRI data and therefore particularly eligible for use in clinical care.