OC10.06: Hemispheric asymmetries in the brain microstructure of healthy fetuses detected <i>in utero</i> by diffusion tensor imaging

Microstructural brain hemispheric asymmetries are a major characteristic of normal human brain organization and cognition. The aim was to evaluate if prenatal diffusion tensor imaging (DTI) can detect microstructure asymmetries in the fetal brain. 15 directions MRI-DTI acquisition of the fetal brain were performed in fetuses without US detected abnormality. Using a motion-correction algorithm, DTI metrics (Fractional Anisotropy (FA), Apparent Diffusion Coefficient (ADC)) were obtained in 23 White matter (WM) and 26 grey matter (GM) regions in both hemispheres. DTI values were compared between the right and the left hemispheres adjusting for the gestational age. The Laterality index [(Left-Right)/(Left+right)] of DTI metrics was calculated for each region to detect hemispheric asymmetries. Laterality index ≥±0.15 defined significant asymmetries. DTI were successful in 94/111(85%) fetuses at 30[21-36] weeks. FA and ADC values were significantly different between hemispheres in the cerebellum, cingulum, frontal cortex, internal capsule, medulla, parietal cortex, vermis, occipital cortex and the corticospinal tract (all p < 0.05). Figure 1 represents the laterality index of DTI metrics. Significant hemispheric asymmetries were detected in the olfactory sulcus, parahippocampal region, cingulum, precuneus region, parietal cortex and the periventricular zone. Brain hemispheric microstructural asymmetries that contribute to future cognitive abilities, future language and visuo-spatial processing or future memorization originate during fetal development and can be detected as early as in mid-trimester by MRI-DTI. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.