Fractional anisotropy alterations in individuals born preterm: a diffusion tensor imaging meta‐analysis

AIM: This meta-analysis explored cerebral microstructural changes in individuals born preterm using fractional anisotropy from diffusion tensor imaging. METHOD: We used the activation likelihood estimate (ALE) method for the meta-analysis to locate anatomical regions with white matter abnormalities in a group of individuals born preterm and in term-born comparison participants. A statistical analysis of fractional anisotropy was conducted to quantitatively explore the extent of fractional anisotropy changes in the three subregions of the corpus callosum in the preterm group. RESULTS: ALE analysis identified 11 regions of decreased fractional anisotropy and four regions of increased fractional anisotropy. Analysis of the corpus callosum revealed the largest decrease in fractional anisotropy in the splenium (standardized mean difference [SMD]=-0.75, 95% confidence interval [CI] -0.93 to -0.57), followed by the body (SMD=-0.73, 95% CI -1.13 to -0.32) and the genu (SMD=-0.65, 95% CI -0.97 to -0.33). INTERPRETATION: Significant changes in fractional anisotropy in individuals born preterm reflect white matter abnormalities from childhood to young adulthood, and the mechanism of fractional anisotropy alterations in preterm infants may vary during different stages of white matter development. Furthermore, the variability of fractional anisotropy between studies can primarily be attributed to the age of the individuals at scanning and to the field strength of magnetic resonance scanners.