Application Value Of 3.0T Susceptibility Weighted Imaging In Neonatal Hypoxic Ischemic Encephalopathy

Objective:1 ? To evaluate the clinical application value of susceptibility weighted imaging(SWI)for hemorrhagic lesions in full-term neonates with hypoxic-ischemic encephalopathy(HIE)and to analyze the relationship between clinical grading and the detection rate of bleeding foci.2?To observe the abnormal appearance of the deep medullary vein in neonatal hypoxic ischemic encephalopathy using the SWI sequence of MRI,and analyze the relationship between the MRI scales and the changes of deep medullary veinin neonates with hypoxic-ischemic encephalopathy and to explore overallly the value of medullary vein dilation(prominence of veins)in the diagnosis of neonatal hypoxic-ischaemic encephalopathy with SWI.Methods:48 full-term neonates with HIE who were hospitalized enrolled from May2017 to December 2017 in the first hospital of JiLin University.The mean age in this study cohort was 7.2days old(range 3~14days old).The clinical criteria were mild,moderate and severe,respectively,24,16,8 cases.Siemens 3.0 t scanner was used for MRI examination.Inspection was performed after sleeping.Scan sequences included:Routine MRI sequence(T1WI?T2WI?T2WI-FLAIR?DWI)and SWI.The Scan scope from calvarium to skull base.Number of cases of in tracranial hemorrhage were detected and to analyze the relationship between clinical grading and the detection rate of bleeding foci.Two high qualification doctor observed and analyzed all imaging of MRI sequence using blind method independently.All the routine MRI imaging and SWI imaging were observed.According to the criteria of MRI scale in HIE,all patients were divided into three groups: mild,moderate and severe.Analyzethe differences of the prominent of medullary vein in SWI between the three groups and the difference of the scores ranking of medullary vein between the three groups separately.SPSS22.0 statistical software is used for statistical data test.Use frequency and rate to express counting date.Comparison of disordered classified data among different groups using Pearson chi-square test.When the sample size of two groups is less than 40,we adopt Fisher exact probalbility method.Comparison of unidirectional ordinal grade data was done in two groups.Mann-Whitney test was used in the comparison between the two groups.Kruskal-Wallis H test was used in many comparisons,and Bonferroni was used to correct the significance in comparison of two groups.The significance level was equal to 0.05..Results: 1.In 48 neonates,Conventional MRI sequences detected in 23 cases with different degree of in tracranial hemorrhage.SWI checked 35 cases.SWI is significantly superior to conventional MRI in displaying the range and boundary definition of hemorrhage.2.There has statistical difference for the detection rate of hemorrhage by SWI among three groups(?2 =19.564,P=0.02).The detection rate of hemorrhage by SWI for mild newborns with HIE was significant lower than that of moderate newborns with HIE(P=0.005)and that of severe newborns with HIE(P<0.001).There has no statistical difference for the detection rate of hemorrhage by SWI between moderate and severe newborns with HIE(P=0.226).3.There has statistical difference for the deep medullary vein in SWI among three groups(?2=11.538,P=0.003).The differences of the abnormal rate of prominent of medullary vein in SWI for mild newborns with HIE was significant lower than that of moderate newborns with HIE(P=0.015<0.0167)and that of severe newborns with HIE(P=0.008<0.0167).There has no statistical difference for the abnormal rate of prominent of medullary vein in SWI between moderate and severe newborns with HIE(P=0.524>0.0167).4.There has statistical difference for the protruding grade of the deep medullary vein in SWI among three groups with the standard of MRI scale in HIE(H=10.068,P=0.007).The differences of the protruding grade of the deep medullary vein in SWI for mild newborns with HIE was significant lower than thatof moderate newborns with HIE(Z=5.811,P=0.015<0.0167)and that of severe newborns with HIE(Z=6.944,P=0.008<0.0167).There was no statistical difference in the degree of deep medullary vein protrusion in SWI between moderate and severe newborns with HIE(Z=0.850,P=0.356>0.0167).Conclusion: 1.SWI sequence was superior to conventional MRI sequence in the detection and displaying of hemorrhage foci,especially microhemorrhage foci,which provided reliable qualitative and quantitative imaging evidence for early diagnosis of HIE and accurate assessment of the degree of brain injury.The detection rate of hemorrhage by SWI for mild neonates with HIE is lower than that of moderate and severe newborns.We can infer the severity to some extent in newborns with HIE according to whether hemorrhage was detected by SWI.SWI has important clinical application value.2.SWI sequence can observe the change of deep medullary vein in neonates with HIE noninvasively.The appearance of deep medullary vein is closely related to the degree of brain injury.It can be a fellow sign of MRI diagnosis for HIE and has certain diagnostic value.