|
Application of shallow scanning in diagnosis of neonatal hypoxic ischemic encephalopathy
HAO Guoxiang,XU Xinyu,GUAN Caixiu,et al.Department of CT,Family Planning Centre Hospital,Hebei 064100,China
［Abstract］ Objective To analyze the application value between head routine CT scanning and shallow scanning in diagnosis of neonatal hypoxic ischemic encephalopathy. Methods 60 neonates with clinically proved hypoxic ischemic encephalopathy underwent head routine CT scanning and shallow scanning and then observed the results of head routine CT scanning and partial shallow scanning,found out the condition of the tissue density in the head. Results 40 neonates under went routine CT scanning.The result was not very clear in low density lesions,18 neonates were indistinct in the high density lesions,2 neonates underwent CT scanning and shallow scanning in high density lesions.The focus was very clear.Conclusion Routine CT scanning and shallow scanning of the tissue density in low and high indistinct density lesions.Show the focus more clearly than simply routine CT scanning especially in the lesions of circuit and groove.Shallow scanning can observe the infinitely change in the lesions of tissue density.Shallow scanning plays an important part in diagnosis of neonatal hypoxic ischemic encephalopathy.
［Key words］ neonate;hypoxic ischemic encephalopathy;shallow scanning
新生儿缺氧缺血性脑病（hypoxic ischemic encephalopathy,HIE)是围产期缺氧引起的脑部损害。主要病因为窒息，据统计约20％留下各种神经系统后遗症［1］，新生儿HIE是造成伤残儿童的主要原因之一。在新生儿期早期准确诊断HIE，使患儿得到早期治疗、减少后遗症，成为广大医务工作者及患儿家属共同关心的问题，头颅CT常规扫描结合薄层扫描更能清晰、准确地显示病变的范围、密度及并发症。
1 对象与方法
1.1 观察对象：收集我院2003年1月～2006年10月资料完整临床确诊为新生儿HIE的患儿60例，行头颅常规扫描结合对兴趣区行薄层扫描，男35例，女25例，足月儿56例，早产儿4例，其中有窒息史40例，呼吸暂停6例，伴青紫征10例，CT检查年龄1~4天，平均为2.6天。
1.2 检查方法：CT机应用美国GE Quant EX型，扫描前30 min给予10％水合氯醛0.5 ml/kg灌肠，取仰卧位，以眶耳线10°角行水平面CT扫描，层厚10 mm，层距10 mm，对兴趣层面选择层厚、层距5 mm扫描。一般扫1～3层，窗宽80～100，窗位35～37，选低密度区测2～3 CT值，求平均值。CT分度按1997年颁布的诊断标准［2］，CT值<18 HU为低密度区，CT值>50 HU为出血，室管膜下—脑室内出血根据CT影像4级［3］，Ⅰ级为室管膜下出血；Ⅱ级为室管膜下出血伴脑室内出血；Ⅲ级为Ⅱ级表现加脑室扩张；Ⅳ级为Ⅲ级表现加广泛性脑损害及脑实质出血。
2 结果
本组60例临床诊断为新生儿HIE患儿，均经头颅CT扫描加薄层扫描，无异常2例，CT为轻度HIE 30例，表现为1～2个脑叶局灶性低密度区不明显，右侧小脑幕缘少许模糊高密度影（图1a），薄扫后，双侧额叶小片状低密度影，右侧小脑幕缘片状高密度影较高，特别清晰（图1b）。CT为中度HIE 20例，低密度影超2个脑叶且伴灰白质界限模糊。10例伴颅内出血，病灶显示对比见图2。CT为重度HIE 5例，呈弥漫性低密度区分布于脑各叶，灰白质界限消失，均合并颅内出血（图3）。室管膜下出血3例，1例合并脑室内出血。图1 a:平扫示右侧小脑幕可见少许条状模糊高密度影；b:薄扫同一层面示右侧小脑幕条状高密度影，显示清晰 图2 a:双侧额颞枕叶散在低密度影，小脑幕呈Y字形高密度影显示欠佳；b:同一层面双侧额枕叶低密度影及小脑幕像呈高脚杯征，脑水肿明显，显示特别清晰 图3 a:小脑幕缘Y字形高密度影，密度较淡，双侧额颞枕叶均匀密度减低；b:薄扫同一层面Y字形高密度影清晰，上矢状窦旁高密度影呈空三角征，额枕叶低密度范围显示更加清晰
|
