围产期脑白质损伤与后期神经纤维发育的关系

目的 应用影像学方法初步探讨围产期脑白质损伤与后期神经纤维发育的关系. 方法 对12例围产期有脑白质损伤的新生儿(早产儿8例,足月儿4例)早期应用超声,后期采用MRI弥散张量成像(DTI)技术进行白质三维重建,并进行部分各向异性(FA)值测定,同时结合临床资料,分析围产期脑白质损伤对后期神经纤维发育的影响及其与临床的对应关系. 结果 早期超声显示脑白质损伤程度重者后期DTI三维重建图像显示神经纤维数量减少明显,向皮层投射减少.定量分析表明,半卵圆中心、额叶白质、枕叶白质、内囊前肢、内囊后肢的FA值在重度脑损伤的患儿分别为0.32±0.08,0.24±0.16,0.27±0.18,0.32±0.06,0.47±0.14,同一部位均较同期正常者(分别为0.46±0.03,0.39±0.02,0.45±0.05,0.50±0.05,0.65±0.02)和轻度脑损伤的患儿(分别为0.43±0.07,0.36±0.09,0.37±0.17,0.39±0.11,0.61±0.05)低(P<0.05);轻度脑损伤患儿的FA值除内囊前肢外多与同期正常者相近(P>0.05).不同部位的脑损伤影像表现随临床症状轻重有不同,且神经系统体征定位与影像定位有一致性. 结论 DTI结果与早期白质损伤程度相符,与临床神经定位一致,该技术对于围产期脑白质损伤的早期诊断和后期神经纤维发育的评价有重要意义.

Relationship between perinatal white matter injury and nerve fibers development

Objective To study the relationship between perinatal white matter injury and nerve fibers development by iconography. Methods Twelve newborns (8 preterm and 4 term neonates) with perinatal white matter injury were examined by transcranial ultrasound in the early period. They were also examined by diffusion tensor imaging (DTI) in the later period. The 3-D images were rebuilt, and fractional anisotropy (FA) values were measured at the same time. Then the effects of perinatal white matter injury on the nerve fibers development were analyzed according to the image and clinical information. Results When the ultrasound image showed that the white matter injury was severe in the early period, the DTI showed that both the amount of nerve fibers and radiation to the cortex reduced. The FA values in centrum ovale, frontal white matter, occipital white matter, anterior and posterior limb of internal capsule for infants with severe injury (0.32±0.08, 0.24±0.16, 0.27±0.18, 0.32±0.06,0.47±0.14, respectively) were lower than those of normal children(0.46± 0.03,0.39±0.02,0.45±0.05,0.50±0.05,0.65±0.02) and infants with mild white matter injury (0.43±0.07,0.36±0.09,0.37±0.17,0.39±0.11,0.61±0.05, respectively) (P<0.05). The FA values in infants with mild white matter injury had no significant difference comparing with normal children (except in anterior limb of internal capsule). The clinical features were different when the images showed different injury areas, and the clinical location of injury was consistent with the images. Conclusions The result of DTI is consistent with the degree of white matter injury and clinical location. DTI is an important method in the study of nerve fibers development after perinatal white matter injury.