Abstract:

Abstract：ObjectiveTo evaluate the dynamic changes of diffusion weighted imaging （DWI） and conventional MRI in neonatal hypoglycemic brain damage. MethodsTwenty neonates with hypoglycemic brain damage diagnosed by MRI from September 2005 to September 2008 were reviewed retrospectively. The clinical data were compared with the data from another 20 neonates with normal MRI findings after hypoglycemia（control subjects）. ResultsCompared with control subjects， the case subjects had lower mean lowest blood glucose level（P < 0.01）.Case subjects’ duration of hypoglycemia was longer than control subjects’（P < 0.01）. In case subjects， the first MRI scan was performed from 1 days to 11 days after hypoglycemia onset， the average being 3.8 days. The occipital and parietal cortex and white matter was involved most frequently，and occipital region was involved in 11 cases，parietooccipital region 8 cases， parietal region 1 case. All involved regions showed hyperintensive signals on DWI； normal signals on both T1WI and T2WI were seen in 12 cases； hypointensity on T1WI and hyperintensity on T2WI were seen in 6 cases. Eleven cases received second scan from 8 days to 15 days after first scan， the average being 11.4 days， 7 cases showed normal signals on DWI. While other 4 cases showed hypointensity. Hypointensity on T1WI and hyperintensity on T2WI were demonstrated in all 11 cases. Three cases was followed-up at 6 months of age，and MRI scan showed normal signals on DWI， hypointensity on T1WI and hyperintensity on T2WI. ConclusionThe sites which show hyperintensive signals on DWI at the early stage of disease are consistent with the foci which show hypointensity on T1WI and hyperintensity on T2WI in subsequent follow-up by conventional MRI. This consistency suggests that DWI seems to be a sensitive early diagnostic measure for disease.

Key words: diffusion magnetic resonance imaging, hypoglycemic brain damage, neonate

摘要：

目的探讨弥散加权成像（DWI）、常规磁共振成像（MRI）在新生儿低血糖性脑损伤不同阶段的动态变化。方法回顾分析了2005年9月至2008年9月，中国医科大学附属盛京医院新生儿科收治的经MRI确诊的20例低血糖性脑损伤患儿（病例组）的临床资料，并随机选取同期住院MRI正常的20例单纯性低血糖患儿为对照组。 结果病例组平均最低血糖值低于对照组（P < 0.01），低血糖持续时间长于对照组（P < 0.01）。病例组于低血糖发生后3.8（1～11）d完成首次MRI检查，受累部位主要为枕叶11例、枕顶叶8例，顶叶1例，受累部位在DWI均表现为高信号，常规MRI相应部位12例表现为T1加权成像（T1WI）、T2加权成像（T2WI）正常信号，仅6例表现为T1WI低信号、T2WI高信号；11例于首次检查后11.4（8～15）d完成第2次MRI检查，首次检查受累部位DWI 7例转为正常信号，4例低信号，常规MRI均表现为T1WI低信号、T2WI高信号。3例于6个月随访，提示枕叶DWI正常信号，T1WI低信号、T2WI高信号。结论新生儿低血糖性脑损伤早期DWI表现为异常高信号的部位，与晚期常规MRI表现为T1WI低信号、T2WI高信号的部位一致，这种一致性提示DWI异常高信号对于低血糖性脑损伤早期病情判断具有一定价值。

关键词: 弥散加权成像, 低血糖脑损伤, 新生儿