The clinical significance of globus pallidus MRI signal intensity in the early identification of neonatal bilirubin encephalopathy / 中国新生儿科杂志

ABSTRACT

Objective To study the clinical significance of globus pallidus signal intensity and the intensity ratio of globus pallidus and putamen (G/P ratio) on magnetic resonance T1WI for the early recognition of neonatal bilirubin encephalopathy.Method From January to December 2017,full-term neonates with hyperbilirubinemia admitted to the neonatology department of our hospital were enrolled in the case group,and full-term neonates without hyperbilirubinemia in the control group.The clinical data,globus pallidus T1WI signal intensity,G/P ratio and the follow-up data were collected.According to the level of hyperbilirubinemia,the neonates in the case group were further assigned into mild hyperbilirubinemia group (serum bilirubin222 to ＜256 μmol/L),moderate hyperbilirubinemia group (serum bilirubin256 to ＜342 μmol/L),and severe hyperbilirubinemia group (serum bilirubin≥ 342 μmol/L).According to the injury score of ABE,the neonates with ABE were assigned into mild ABE group,moderate ABE group and severe ABE group.The correlation of globus pallidus T1WI and T2WI signal values,G/P ratio and the serum bilirubin level and ABE degree were analyzed;receiver operating characteristic (ROC) curve was drawn to explore the predictive value of the T1WI signal value and G/P ratio for the diagnosis of ABE;the changes of globus pallidus T1WI and T2WI signal values during the first 6 months after birth and the results of follow-up to 1 year after discharge were also analyzed.Result A total of 175 neonates were included in the case group (65 in the mild hyperbilirubinemia group,71 in the moderate hyperbilirubinemia group and 39 in the severe hyperbilirubinemia group) and 43 neonates in the control group.39 neonates were diagnosed as ABE (21 mild ABE,12 moderate ABE,and 6 severe ABE).The first T1WI signal value and G/P ratio of neonates in the severe hyperbilirubinemia group was higher than the moderate hyperbilirubinemia group,the mild hyperbilirubinemia group and the control group;the T1WI signal value and G/P ratio in the moderate hyperbilirubinemia group was higher than the mild hyperbilirubinemia group and the control group (P ＜ 0.05).No significant difference existed between the mild group and the control group(P ＞ 0.05).T2WI values showed no differences among neonates with different bilirubin levels (P ＞ 0.05).The first T1WI signal value and G/P ratio in the severe ABE group were significantly higher than the moderate and mild ABE group,and the moderate ABE group higher than the mild ABE group (P ＜ 0.05).The ROC curve indicated the optimal cut-off value of T1WI signal and G/P ratio were 628 and 1.38,respectively.Among all the 175 neonates,9 had a decrease in T1WI signal value and an increase in T2WI signal value at 6 months after birth.After 1 year of follow-up visits,7 children were finally diagnosed as chronic bilirubin encephalopathy.All these children had increased signal intensity on T1WI in the acute phase,plus a decreased T1WI signal and an increased T2WI signal in 1 ～ 6 months after birth.Conclusion The globus pallidus T1WI signal and G/P ratio are closely related to the serum bilirubin level and ABE severity.If T1WI signal value ＞ 628 or G/P value ＞ 1.38,ABE should be considered.The T1WI signal value and G/P ratio play important roles as indicators for the early recognition of neonatal bilirubin encephalopathy.