The Clinical Value Of The Signal Intensity In Globus Pallidus Analysis On MRI In Neonatal Hyperbilirubinemia

Objective To provide clinical evidence for early diagnosis and prognosis evaluation of neonatal bilirubin encephalopathy through study on the clinical value of the signal intensity in globus pallidus analysis on MRI and the G/P ratio in neonatal hyperbilirubinemia.Method:Full-term newborns with hyperbilirubinemia admitted to the Neonatology Department,Chenzhou Children’s Hospital from January 1,2017 to December 31,2017 were enrolled in the study.Hospitalization data,including gestational age,birth weight,admission time,disease time,serum total bilirubin,BEAP,BIND score,head MRI and clinical manifestation,and post-discharge follow-up data of these patients were collected.All these subjects were assigned into mild,moderate and severe groups based on the level of bilirubin.The bilirubin encephalopathy was classified as mild,moderate and severe disease based on the acute bilirubin-induced brain damage score.The correlation between globus pallidus T1 WI,T2WI signal value and G/P ratio and serum bilirubin level,ABE classification was statistically analyzed.The sensitive T1 WI signal intensity and G/P ratio for the diagnosis of acute bilirubin encephalopathy was identified via ROC curve.The overall 6-month clinical follow-up and globus pallidus T1 WI,T2WI signal intensity changes were analyzed to investigate the clinical application value of globus pallidus T1 WI,T2WI signal value and G/P ratio in neonatal hyperbilirubinemia.Result:(1)Comparison of baseline globus pallidus T1 WI,T2WI signal value and G/P ratio on MRI among these four groups The difference of T2 WI signal among these four groups was not statistically significant(P>0.05).The difference of T1 WI signal and G/P ratio among these four groups was statistically significant(P<0.05),the values in the severe group were higher than in the moderate,mild and normal groups,and the moderate group higher than the mild and normal groups,all differences were statistically significant(P< 0.05).The difference between the mild and the normal groups was not statistically significant(P>0.05).(2)The comparison of T1 WI signal and G/P ratio among the mild,moderate and severe ABE groups The intra-group differences of T1 WI signal and G/P ratio in these three groups were statistically significant(P< 0.05).Pairwise comparison: Values in the severe group were higher than in the moderate and mild groups,and the moderate group higher than in the mild and normal groups,all differences were statistically significant(P<0.001).(3)ROC curve analysis on T1 WI signal-and G/P ratio-based ABE evaluation the ROC area under the curve(AUC)of T1 WI signal was 0.728,the optimal cut-off was 628.25,the sensitivity was 0.718 and the specificity was 0.584.The ROC AUC of G/P ratio was 0.810,the optimal cut-off was 1.3805,the sensitivity was 0.641 and the specificity was 0.774.(4)One hundred and seventy five children patients underwent 1-3 times of reexamination within half a year after birth.The level of globus pallidus T1 WI and T2 WI signals was observed for increase.The first drop of T1 WI signal with increase of T2 WI signal occurred within the first 1-2 months in two cases,within 2-3 months in six cases and 5-6 months in one case.(5)Follow-up result In 175 children patients who were followed-up within one year after birth,7 cases were diagnosed with chronic bilirubin encephalopathy with globus pallidus T1 WI signal increase in acute period,T1 WI drop and T2 WI signal increase within 2-6 months.The main major clinical manifestation includes decreased responsiveness,lethargy,increased or decreased muscular tension,convulsions,and opisthotonus.Five developed severe sequela,including 3 cases of sialorrhea,one case of dysphagia and one case of bilateral hearing disorder.Conclusion(1)The bilateral globus pallidus T1 WI signal and G/P ratio in acute period are closely correlated with the serum total bilirubin level and ABE score.The higher the total bilirubin level and ABE score,the higher the T1 WI signal and G/P ratio.(2)When bilateral globus pallidus T1 WI signal is greater than 628.25 or G/P ratio greater than 1.3805,the ABE may be diagnosed in combination with the clinical symptom.The specificity of G/P in diagnosis of ABE is higher than that of the T1 WI signal.(3)The T2 WI signal enhancement occurs mainly in 2-3 months after birth.The T2 WI signal enhancement indicates poor prognosis.T2 WI is clinically significant for chronic bilirubin encephalopathy.(4)Dynamic test of MRI globus pallidus signal and G/P ratio is of great significance to the diagnosis and prognosis evaluation of bilirubin encephalopathy.