Background: Advances in neonatal intensive care have not yet reduced the high incidence of neurodevelopmental disability among very-low-birth-weight (VLBW) infants. As neurological deficits are related to white-matter injury, early detection is important. Diffusion tensor imaging (DTI) could be an excellent tool for assessment of white-matter injury. Objective: To provide DTI fractional anisotropy (FA) reference values for white-matter tracts of VLBW infants for clinical use. Materials and methods: We retrospectively analysed DTI images of 28 VLBW infants (26-32 weeks gestational age) without evidence of white-matter abnormalities on conventional MRI sequences, and normal developmental outcome (assessed at age 1-3 years). For DTI an echoplanar sequence with diffusion gradient (b = 1,000 s/mm2) applied in 25 non-collinear directions was used. We measured FA and apparent diffusion coefficient (ADC) of different white-matter tracts in the first 4 days of life. Results: A statistically significant correlation was found between gestational age and FA of the posterior limb of the internal capsule in VLBW infants (r = 0.495, P<0.01). Conclusion: Values of FA and ADC were measured in white-matter tracts of VLBW infants. FA of the pyramidal tracts measured in the first few days after birth is related to gestational age.

Diffusion tensor imaging, Fractional anisotropy, MRI, Prematurity,
Pediatric Radiology: roentgenology, nuclear medicine, ultrasonics, CT, MRI
Erasmus MC: University Medical Center Rotterdam

Dudink, J, Leguin, M, van Pul, C, Buijs, J, Conneman, N, van Goudoever, J.B, & Govaert, P. (2007). Fractional anisotropy in white matter tracts of very-low-birth-weight infants. Pediatric Radiology: roentgenology, nuclear medicine, ultrasonics, CT, MRI, 37(12), 1216–1223. doi:10.1007/s00247-007-0626-7