ALEActivation likelihood estimate DTI Diffusion tensor imaging SMD Standardized mean difference 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]=À0.75, 95% confidence interval [CI] À0.93 to À0.57), followed by the body (SMD=À0.73, 95% CI À1.13 to À0.32) and the genu (SMD=À0.65, 95% CI À0.97 to À0.33).
INTERPRETATION Significant changes in fractional anisotropy in individuals born pretermreflect 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.Preterm birth is frequently accompanied by a variety of disabilities, such as cerebral palsy, intellectual disability, deafness, or blindness. The incidence of preterm birth has increased significantly in the past decades, but is associated with higher survival rates 1 and a lower incidence of major disabilities than in the past.2 However, there is strong evidence that preterm survivors without brain malformations, congenital infection, or metabolic disease and with normal outcomes or mild abnormalities on structural brain magnetic resonance imaging (MRI) may experience more problems of motor, cognitive, language, and behavioural functioning throughout childhood and young adulthood. [3][4][5][6] These sequelae have been attributed to perinatal brain injuries, 7,8 which frequently involve white matter, 9 during normal brain maturation. 10 Nevertheless, the location, severity, and mechanism of white matter injuries on neurodevelopment and their impact on future function have not been conclusively determined.11 Additional neuroimaging evidence is necessary to explain the mechanism of white matter injuries and to predict the future influence of these impairments in individuals who are born preterm.Diffusion tensor imaging (DTI), a novel MRI technique, can quantify the fibre orientation and integrity of white matter pathways within neural networks. This technique is superior to conventional MRI methods for the detection of white matter abnormalities becaus...