Abstract: Objective：Based on the magnetic resonance manifestations and clinical characteristics of brain white matter injury in late preterm infants(LPIs), to evaluate their mental development and psychomotor development, and to discuss the effects of different degrees of white matter injury on the neurological development of late preterm infants.
Methods：From February 15,2013 to March 12,2018,139 late preterm infants accepted MRI examination at 8-14 days after birth in Shenyang Women and Children's Hospital.Totally,114 LPIs were followed up at one year old, and their mental development index(MDI) and psychomotor development index(PDI) were measured, which were used to evaluate the neurological development of these children.
Results：In the 114 late preterm infants, those with mental dysfunction and psychomotor dysfunction had significantly lower average gestational age, birth body mass and l min Apgar score than the children with normal mental and psychomotor development; the time for taking low flow oxygen was significantly prolonged, and there was statistical difference(P<0.05). The more severe the brain white matter injury and the higher the degree of ventriculomegaly, the more likely the mental and psychomotor dysfunction in these children.
Conclusion：The more severe the brain white matter injury and the ventriculomegaly in the late preterm infants, the poorer the outcome of neurological development.The more severe the brain white matter injury and the ventriculomegaly in the late preterm infants, the poorer the outcome of neurological development.

Key words: White matter damage, Late premature infants, Magnetic resonance changes, MDI, PDI