Characterization of Fetal Brain Development with Diffusion Tensor Magnetic Resonance Imaging

Human brain anatomy is characterized by dramatic structural changes during fetal development. It is extraordinarily complex and yet its origin is asimple tubular structure. Revealing detailed anatomy at different stages of human fetal brain development not only aids in understanding this highlyordered process, but also provides clues to detect abnormalities caused by genetic or environmental factors. For example, the characterization ofwhite matter axon growth could provide important clues to understanding the inhomegeneity of white matter injuries in cerebral palsy. However,anatomical studies of human brain development during this period are surprisingly scarce, and histology-based atlases have only recently becomeavailable. Diffusion tensor imaging (DTI), a novel method of magnetic resonance imaging (MRI), is capable of delineating anatomical components withhigh contrast and revealing structures at the microscopic level. The volumetric measurement from 3D DTI data can quantify structural growth. Asdiscussed in this article, the fetal brain DTI database will be a valuable resource for human brain developmental study and will provide referencestandards for diagnostic radiology of premature newborns.