早产儿脑白质损伤早期磁共振成像改变及其高危因素分析

摘要：目的　以磁共振成像（MRI）提供的影像学资料为依据，评价早产儿脑白质损伤的早期MRI变化及其临床意义，并探讨其高危因素。方法　选取2007年9月至2009年9月中国医科大学附属盛京医院儿科收治的262例早产儿，全部在7 d内完成磁共振检查，根据MRI诊断早产儿脑白质损伤，分为病例组134例，对照组128例。并对病例组29例患儿进行二次复查。结果　（1）早产儿脑白质损伤早期，局灶性病变表现弥散加权成像（DWI）高信号，T1加权（T1WI）信号正常或稍高信号，伴有或不伴有T2加权（T2WI）低信号；弥漫性脑白质损伤仅能看到DWI弥漫性高信号，常规MRI无信号改变。复查结果，局灶性病变有两种情况：一是病灶消失，二是DWI高信号消失或稍高信号，T1WI高信号，伴或不伴有T2WI低信号；弥漫性病变，发生脑室周围白质软化，表现为T2WI高信号或高低混杂信号， DWI异常信号消失或高低混杂信号，T1WI高低混杂信号。（2）病例组与对照组在胎龄，出生体重差异无统计学意义。单因素分析：母孕期感染、双胎、代谢性酸中毒、低钙、低氧、机械通气和感染与早产儿早期脑白质损伤有统计学意义。Logistic模型多因素分析，母孕期感染、低氧和胎儿宫内窘迫是早产儿早期脑白质损伤的危险因素。结论　（1）DWI能发现早期脑白质损伤病变。（2）早产儿脑白质损伤是多种因素相互作用的结果：母孕期感染、胎儿宫内窘迫及出生后低氧与早产儿早期脑白质损伤有密切关系。（3）早产儿脑白质损伤早期临床表现缺乏特异性，建议常规行头MRI检查，且脑白质信号异常均需要动态随访观察。

Research on the MRI and related factors in the preterm infants with early cerebral white matter damage.

Abstract： Objective　To assess the early changes of MRI and its clinical significance in the preterm infants with the cerebral white matter damage（CWMD），based on the data offered by MRI， and to investigate the related factors. Methods　The research was prospectively performed on 262 preterm infants from September 2007 to September 2009 at the neonatal ward of the Shengjing Hospital of China Medical University. All  were performed MRI examination in 7 days；subjects were classified into two groups according to MRI diagnostic criteria： case group and control group. Of case group，29 were followed up. Results　（1）Focal injury，high signal appeared on DWI，with normal or slightly high signal on T1WI，accompanying low or normal signal on T2WI.The diffuse injury，diffusive high signal only on DWI， no abnormal signal on regular MRI. After about two weeks，focal lesions have been shown in two ways：① lesion vanished ② normal or slightly high signal on DWI， while on T1WI high signal and low or normal signal on T2WI，diffuse injury have been change into periventricular leukomalacia（PVL），High signal or miscellaneous （high and low）signal on T2WI，while on T1WI and DWI， miscellaneous signal .（2）Related factors were analyzed.Univariate analysis， perinatal infection， twins， hypocalcaemia， metabolic acidosis， hypoxia，mechanical ventilation and infants infection for preterm CWMD were considered statistically significant. Logistic Regression  analysis showed that perinatal infection， hypoxia and intrauteral embarrassment were risk factors for preterm infants with CWMD. Conclusion　（1）DWI can detect the lesions in early stage of CWMD.（2）The interaction of multiple factors，includly the premature infant CWMD， perinatal infection，hypoxia and intrauteral embarrassment has close relationship with the CWMD.（3）There are no specific clinical manifestations of CWMD，so it is suggested MRI should be performed as a routine in preterm infants，and follow up is necessary if abnormal signal appears.