MR-DTI Study Of Potential Brain Injury In Full-term Neonatal Hyperbilirubinemia

Objective:1.To investigate the value of diffusion tensor imaging(DTI)on the potential cerebral injury of Hyperbilirubinemia in full term newborns.2.To investigate the relationship between the fractional anisotropy(FA)values of DTI with serum free bilirubin(UCB),serum total bilirubin(TSB)ancd the ratio of TSB/albumin(B/A)in brain vulnerable area of hyperbilirubinemia.Methods:Between July 2016 and October 2017,a total of 62 full term neonates with jaundice diagnosed as HB in our hospital were studied.Other 47 healthy full term neonates were collected as normal control group(group ?).The age,sex,birth weight,serum total bilirubin level,free bilirubin level and albumin count were recordecd.According to serum bilirubin level,a total of 62 mature newborns with HB(study group)were divided into two groups:slightly elevated group(group ?:220.6?342.0?mol/L,n?44)and Moderate to severe elevation group(group ?:TSB?342 ?mol/L,n=18).Cerebral MRI was performed during the bilirubin at peak levels within one week.The cerebral MRI sequence included T1WI translocation and sagittal position,T2WI and liquid inversion recovery sequence(FALIR)translocation and DTI imaging.The FA images were obtained by two radiologists with rich experience.Bilateral globus pallidus,brain stem,posterior branch of internal capsule,thalamus and dentate nucleus of cerebellum were selected as areas of interest,and FA values of each site were obtained.To explore the differences of FA values in different anatomical sites and the relationship of FA values with UCB?TSB and B/A.Result:1.There were no statistically significant in sex ratio,birth age and weight among the three groups(all P>0.05).2.There were no statistically significant of FA values in the bilateral anatomical sites:globus pallidus,posterior limb of internal capsule,dentate nucleus,and cerebral ganglia(P>0.05).3.In normal control group,positive linear correlation existed between the FA values of brain stem and birth age,but not with birth weight.4.There were significant differences in FA values of brain stem between normal control group,group ? and group ?(F=12.788,P =0.000),There were no statistical significance between group ? and group ?(P = 0.081);There were no significant difference of FA value in dentate nucleus,thalamus,globus pallidus and posterior limb of internal capsule(P>0.05).5.When the age and birth weight were controlled,the FA values of brain stem in group ? was positively correlated with TSB(r?-0.353,p=0.018)?and UCB(r?-0.366,p=0.018),but not with B/A(p>0 0.05).As the level of bilirubin increased,the correlation was enhanced.In group ?,there were moderately correlation between FA value of brain stem with TSB(r=-0.702,p=0.001),UCB(r=-0.724,p=0.000),and B/A(r=-0.709,p?0.003).Conclusion:This study showed that the DTI-FA values of brainstem were different from those in normal controls and negatively correlated with bilirubin concentrations in newborns with hyperbilirubinemia.When the age and birth weight were controlled,the DTI-FA value of brain stem was correlated with bilirubin concentration.When the concentration of bilirubin was more than 342 ?mol/L,the correlation was significantly increased.However,there was no correlation between the FA value and the concentration of bilirubin in the dentate nucleus,globus pallidus,posterior limb of internal capsule and the thalamus region.Furthermore,it was concluded that DTI-FA value of brain stem was valuable for the diagnosis of neonatal brain white matter injury of hyperbilirubinemia.