MRI在新生儿核黄疸诊断中的应用

目的 探讨新生儿核黄疸的MRI表现,为临床诊断与随访提供客观的影像学依据. 方法 21例具有典型临床表现的核黄疸患儿在生后接受了头部高场MRI检查,场强为1.5 Tesla,扫描序列包括T1WI,T2WI和DWI,2名不知被检者病史的放射科医师分析MRI 结果.结果 21例新生儿生后2～11天首次MRI检查有19例(约占90.5%)TIWI上双侧苍白球信号对称性增高(其中3例3个月后复查MRI显示T2WI上双侧苍白球对称性高信号),另外2例(约占9.5 %)信号未见改变.上述病例DWI上信号均未见特殊改变. 结论 新生儿期核黄疸主要表现为T1WI上双侧苍白球对称性高信号;后遗症期核黄疸主要表现为T2WI上双侧苍白球对称性高信号;DWI对诊断核黄疸无帮助.

The value of MRI in the diagnosis of kernicterus in newborn infants

Objective The aim of this study was to document the magnetic resonance imaging(MRI)findings of kernicterus of newborn and provide evidences for diagnosis of kernicterus and prediction of outcome. Methods 21 neonates(ages of 2d-3m) who were admitted with jaundice,encephalopathy and indirect hyperbilirubinemia(560.87 ±140.88)μmol/ L] were prospectively evaluated with cranial MR imaging. The magnetic field strength of MR was 1.5 Tesla. Routine T1WI、T2WI and DWI were applied. Two neuroradiologists who knew nothing about the clinical history analyzed MRI findings. Unconjugated bilirubin(UCB)in all these neonates were measured with the same methods and analyzer. Results 19 of the 21(90.5%)neonates demonstrated bilateral,symmetric increased signal intensity in the globus pallidus on T1WI,of whom seven had remarkable increasing,and three neonates had symmetric hyperintense golbus pallidus on T2WI at the same time. The MR imaging findings of the other two(9.5%)patients showed no evidence of abnormality. Higher UCB (580.95±132.44) μmol/ L] were found in 19 neonates with hyperintense globus pallidus as compared to two cases (350.3μmol/ L、389.9μmol/ L )without changes of globus pallidus. Three infants received the second MRI at ages of 3 months,and showed symmetric hyperintense golbus pallidus on T2WI,one of three infants also had T2WI hyperintensity at first MRI. Conclusion The symmetric involvement of globus pallidus seen as hyperintense on T1WI is a common and characteristic finding of acute kernicterus;T2WI hyperintensity is the characteristic finding of chronic kernicterus;DWI is no diagnostic value in kernicterus. The symmetric involvement of globus pallidus with hyperintense signals on T1WI probably indicates the severity of bilirubin encephalopathy.