摘要目的 探讨苍白球磁共振T1WI信号值及苍白球与壳核T1WI信号强度比值(G/P值)在新生儿胆红素脑病早期识别中的意义.方法 选取2017年1～12月南华大学附属郴州医院新生儿科收治的高胆红素血症足月新生儿为病例组,同期入院的非高胆红素血症足月新生儿为对照组.收集临床资料、苍白球T1WI信号值、G/P值及出院后随访资料等.根据胆红素水平将病例组患儿分为轻度高胆组(222-＜256 μmol/L)、中度高胆组(256～＜342 μmol/L)、重度高胆组(≥342 μmol/L);根据急性期胆红素脑损伤评分将急性胆红素脑病(acute bilirubin encephalopathy,ABE)患儿分为轻度ABE组、中度ABE组、重度ABE组.分析苍白球T1WI、T2WI信号值和G/P值与血清胆红素水平、ABE程度的关系,通过受试者工作特征曲线找出诊断ABE的T1WI信号值和G/P值;并对生后6个月苍白球T1WI、T2WI信号值的动态变化和生后1年的临床随访结果进行综合分析.结果 病例组共纳入175例,其中轻度高胆组65例,中度高胆组71例,重度高胆组39例;对照组43例.诊断ABE39例,其中轻度ABE组21例,中度ABE组12例,重度ABE组6例.不同胆红素水平新生儿首次T1WI信号值、G/P值比较,重度高胆组高于中度高胆组、轻度高胆组和对照组,中度高胆组高于轻度高胆组和对照组,差异均有统计学意义(P＜0.05),轻度组与对照组比较差异无统计学意义(P＞0.05).不同胆红素水平新生儿T2WI值比较,T1WI、T2WI值左右侧比较,差异均无统计学意义(P＞0.05).不同程度ABE患儿首次T1WI信号值、G/P值比较,重度ABE组高于中度ABE组和轻度ABE组,中度ABE组高于轻度ABE组,差异均有统计学意义(P＜0.05).受试者工作特征曲线分析,T1WI信号值和G/P值的最佳临界点分别为628和1.38.175例患儿生后6个月内发现9例T1WI信号值下降伴T2WI信号值升高.随访1年,最终诊断慢性胆红素脑病7例,均为急性期苍白球T1WI信号增高,生后1～6个月内出现T1WI降低伴T2WI信号值增高的患儿.结论 苍白球T1WI信号值及G/P值与血清总胆红素水平、ABE分度有密切关系,T1WI信号值＞628或G/P值＞1.38需考虑ABE.测定T1WI信号值及G/P值对新生儿胆红素脑病的早期识别有重要参考价值.

abstractsObjective 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 bilirubin:222 to ＜256 μmol/L),moderate hyperbilirubinemia group (serum bilirubin:256 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.