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Backgroud: Recent advances in diffusion MRI present new opportunities to examine brain development.Using biophysical models of brain tissues it is possible to relate diffusion-weighted signals directly to the underlying cellular microstructure.They proposed a sphere for the glial cells and ellipsoids for the axons with water exchanging between the intra-and extra-axonal compartments.The CHARMED(composite hindered and restricted model of diffusion)and NODDI(neurite orientation dispersion and density imaging)are potentially more sensitive to cellular microstructure and able to extract parameters of the cellular geometry,axonal density and axonal diameter.The two-compartment WM Diffusin Kurtosis Imaging(DKI)model have the potential to provide new markers to study the complex process of human white matter(WM)development.In addition,the diffuse excessive high signal intensity(DEHSI)is extremely common in preterm infants on near-term images.It is still under debate about whether it represents a true WM abnormality or just the relative immature in WM.The aim of this study was exploring the water diffusivity in DEHSI regions based on the two-compartment WM DKI model.