Structural MRI and tract-based spatial statistical analysis of diffusion tensor imaging in children with hemimegalencephaly.

Abstract

To investigate the gross white matter abnormalities in the structural brain MR imaging as well as white matter microstructural alterations using tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) in both affected and contralateral cerebral hemispheres of children with hemimegalencephaly (HMEG). From 2003 to 2019, we retrospectively reviewed brain MR images in 20 children (11 boys, 2days-16.5years) with HMEG, focusing on gross white matter abnormalities. DTI was evaluated in 12 patients (8 boys, 3months-16.5years) with HMEG and 12 age-, sex-, and magnetic field strength-matched control subjects. TBSS analysis was performed to analyze main white matter tracts. Regions of significant differences in fractional anisotropy (FA) were determined between HMEG and control subjects and between affected and contralateral hemispheres of HMEG. Gross white matter abnormalities were noted in both affected (n = 20, 100%) and contralateral hemisphere (n = 4, 20%) of HMEG. FA values were significantly decreased in both hemispheres of HMEG, compared with control subjects (P < 0.05). Contralateral hemispheres of HMEG showed regions with significantly decreased FA values compared with affected hemispheres (P < 0.05). In addition to gross white matter abnormalities particularly evident in affected hemispheres, DTI analysis detected widespread microstructural alterations in both affected and contralateral hemispheres in HMEG suggesting HMEG may involve broader abnormalities in neuronal networks.