Mao Jian, Fu Jian-hua, Chen Li-ying, Wang Xiao-ming, Xue Xin-dong
Department of Pediatrics, Second Affiliated Hospital of China Medical University, Shenyang 110004, China.
Zhonghua Er Ke Za Zhi. 2007 Jan;45(1):24-9.
The involvement of globus pallidus has been found in neonates with acute bilirubin encephalopathy (ABE), but so far the relationship between the severity of hyperbilirubinemia and changes of globus pallidus has not been studied further. The present study was conducted to understand possible relationship between the MRI signal changes of globus pallidus and severe hyperbilirubinemia in the neonates to provide evidences for diagnosis of bilirubin encephalopathy and prediction of outcome.
Thirty-six neonates with severe hyperbilirubinemia (total serum bilirubin, i.e., TSB > 342 micromol/L) received MRI examination in a magnetic field with the strength of 1.5 - 3.0 Tesla at ages of 10 +/- 6 (2 - 34) days of life, of whom 15 were assessed as acute bilirubin encephalopathy (ABE). Routine T1WI with three kinds of sequences (SE, IR and FFE), T2WI and DWI with two kinds of sequences (EPI-SE and DW SSh SENSE) were applied. Two neuroradiologists who knew nothing about the clinical history analyzed MRI findings. TSB, unconjugated bilirubin (UCB), conjugated bilirubin (CB) and albumin (ALB) in all these neonates were measured with the same methods and analyzer.
Symmetric hyperintense globus pallidus was shown on T1WI in 20 neonates, of whom three had symmetric hyperintense globus pallidus on T2WI (TSB = 745.3 micromol/L, 735.7 micromol/L, 707.6 micromol/L, respectively) at the same time. Remarkably higher TSB, molar ratio of TSB and ALB (B/A) and UCB were found in 20 neonates with hyperintense globus pallidus as compared to 16 cases without changes of globus pallidus (P = 0.000). No abnormal signal changes were found on DWI for all neonates; 9 neonates with TSB ranged from 342.0 micromol/L to 427.5 micromol/L did not show any abnormalities of globus pallidus, 3 of 7 neonates with TSB ranged from 427.5 micromol/L to 513.0 micromol/L, but 17 of 20 neonates with TSB more than 513.0 micromol/L showed distinct hyperintense globus pallidus. Hyperintense globus pallidus on T1WI was related to the severity of hyperbilirubinemia (Fisher's Exact Test, P = 0.000). Hyperintense globus pallidus on T1WI was found in all the 15 neonates with ABE (Fisher's Exact Test, P = 0.000), at the same time, hyperintense globus pallidus on T2WI was found in 3 cases with severe ABE. Six infants received the second MRI at ages from 2 months to 12 months, two of three infants with ABE in neonatal period showed the signal changes of globes pallidus from T1WI hyperintensity to T2WI hyperintensity and they developed cerebral palsy. The other one with normal signal showed hearing dysfunction. Another three infants without history of ABE did not show abnormal signals of globus pallidus and developed normally.
The symmetric involvement of globus pallidus with hyperintense signals on MRI T1WI indicates the severity of hyperbilirubinemia, which relates to time of exposure to hyperbilirubinemia and is a characteristic finding of ABE. The signal switch of hyperintense globus pallidus from T1WI to T2WI predicts poor outcome.
已发现急性胆红素脑病(ABE)新生儿存在苍白球受累情况,但迄今为止,高胆红素血症严重程度与苍白球变化之间的关系尚未进一步研究。本研究旨在了解新生儿苍白球MRI信号变化与严重高胆红素血症之间的可能关系,为胆红素脑病的诊断和预后预测提供依据。
36例严重高胆红素血症(血清总胆红素,即TSB>342μmol/L)新生儿在出生后10±6(2 - 34)天,于1.5 - 3.0特斯拉磁场强度下接受MRI检查,其中15例被评估为急性胆红素脑病(ABE)。采用三种序列(SE、IR和FFE)的常规T1WI、两种序列(EPI-SE和DW SSh SENSE)的T2WI和DWI。两名对临床病史不知情的神经放射科医生分析MRI结果。所有这些新生儿的TSB、非结合胆红素(UCB)、结合胆红素(CB)和白蛋白(ALB)均采用相同方法和分析仪进行测量。
20例新生儿T1WI显示苍白球对称高信号,其中3例同时T2WI显示苍白球对称高信号(TSB分别为745.3μmol/L、735.7μmol/L、707.6μmol/L)。与16例苍白球无变化的新生儿相比,20例苍白球高信号新生儿的TSB、TSB与ALB摩尔比(B/A)和UCB显著更高(P = 0.000)。所有新生儿DWI均未发现异常信号;9例TSB在342.0μmol/L至427.5μmol/L之间的新生儿未显示苍白球任何异常,7例TSB在427.5μmol/L至513.0μmol/L之间的新生儿中有3例,而20例TSB超过513.0μmol/L的新生儿中有17例显示明显的苍白球高信号。T1WI上苍白球高信号与高胆红素血症严重程度相关(Fisher精确检验,P = 0.000)。15例ABE新生儿T1WI均显示苍白球高信号(Fisher精确检验,P = 0.000),同时,3例严重ABE患儿T2WI显示苍白球高信号。6例婴儿在2个月至12个月龄时接受了第二次MRI检查,新生儿期有ABE的3例婴儿中有2例显示苍白球信号从T1WI高信号变为T2WI高信号,且发展为脑瘫。另1例信号正常的婴儿出现听力障碍。另外3例无ABE病史的婴儿未显示苍白球异常信号,发育正常。
MRI T1WI上苍白球对称受累且信号高提示高胆红素血症的严重程度,这与高胆红素血症暴露时间有关,是ABE的特征性表现。苍白球高信号从T1WI转变为T2WI预示预后不良。