The Preliminary Study Of Brain Injuries Of Preterm Infants With Conventional MRI And DTI

Objctive：To explore the features of brain injury of preterm infants with conventional MRI andDTI (diffusion tensor imaging, DTI).Methods：127preterm infants underwent conventional MRI and DWI (diffusion-weightedimaging, DWI), and DTI. The field of MRI scanner was1.5Tesla. All infants were recruitedfrom our NICU (neonate intensive care unit, NICU) and maternity department. These infantswere divided into two groups by their correct GA (gestational ages, GA): group1was notterm-equivalent; group2was at TEA (term-equivalent age). The findings of conventional MRI、DWI were analyzed. The values of FA (fractional anisotropy, FA) and ADC (apparent diffusioncoefficient, ADC) were measured with Functool software automatically. The ROIs(regions ofinterest, ROI) were bilateral posterior limb of internal capsule, frontal white matter, occipitalwhite matter and lentiform nuclei on the basal ganglia section. Statistical analysis was performedwith SPSS.Results：There were66preterm infants was recruited into this study totally. According to MRIfindings, the infants before TEA and at TEA were further subgrouped into two groups seperately:14subjects with normal MR findings were assigned to Group1(GA226.4±16.1d; correct GA249.7±8.3d);10subjects with abnormal MR findings were assigned to Group2(GA235.1±18.8d; correct GA276.6±9.3d);14subjects with normal MR findings were belong toGroup3(GA225.4±17.1d; correct GA249.5±8.3d);14subjects with abnormal MR findingswere Group4(GA234.8±18.8d; correct GA275.7±9.3d). The postnatal days at imaging of allinfants were2-57d. There was no statistic significance of correct GA at the day of imagingbetween group2and group4（t=0.648，P=0.533）. There was no statistic significance of correctGA at the day of imaging between group1and group3（t=2.710，P=0.128）.(1) The braindamage were found in56cases with conventional MRI and DWI. Among these lesions, cerebraledema (mild to moderate) of10cases, intracranial hemorrhage of16cases, periventricularwhite matter damage in6cases, and DEHSI were demonstrated in54cases.(2)There was nostatistic significance of ADC、FA value of bilateral hemisphere of four groups.(3) There wasstatistic significance of ADC value of frontal white matter between group2and group4(t=-9.055，P=0.000). There was statistic significance of ADC value of lentiform nuclei betweengroup1and group3(t=2.263，P=0.032).(4)There was statistic significance of FA value ofposterior limb of internal capsule, frontal white matter between group2and group4(t=-3.075，P=0.005)(t=2.486，P=0.022). Conclusion:(1) There are different types of brain injuries in preterm infants were demonstratedon conventional MRI and DWI.(2) FA and ADC values were valuable in demonstrating the brain changes of preterm infants atTEA or before TEA in quantity..