摘要
目的分析兔脑急性缺血组织磁共振弥散成像（DWI）的影像学表现及其与细胞凋亡的关系，探讨DWI成像的病理基础。方法58只新西兰大白兔随机分为永久缺血组（A组）和再灌注组（B组），线栓法制作大脑中动脉缺血和缺血再灌注模型。其中A组分为缺血1、3、6、12、24与48h（A1～A6）组；B组缺血1h拔线再通后分为再灌注0、2、5、11、23和47h（B1～B6）组。每组分别于各自时间点进行DWI成像，分别测量表观弥散系数（ADC）值并计算相对ADc（rADC）值。兔脑标本行细胞凋亡检测。结果A组DWI高信号区逐渐增大，缺血24h趋于稳定；ADC值呈先下降后上升的变化趋势。B组平均ADC值的变化呈双峰改变，缺血再灌注2h的rADC值趋于正常化，DWI高信号区减小；5h的rADC值最低，以后rADC值逐渐升高，DWI高信号区逐渐扩大。永久缺血组细胞凋亡逐渐增多，12h达高峰，以后缓慢下降；再灌注组细胞凋亡数逐渐增多，幅度较永久缺血组低，高峰出现于再灌注23h。结论细胞凋亡的发生与缺血的程度和持续时间有关，但细胞凋亡与ADC值的演变规律没有明显的相关性。
Objective To analyze the relationship between cell apoptosis and Apparent Diffusion Coefficient （ADC） and explore the pathomechanism of DWI in rabbits undergoing reperfusion after acute cerebral ischemia. Methods Fifty eight New zeland white rabbits were divided into two groups in random： group A （permanent-ischemia group） and group B （reperfusion group）. Models of middle cerebral artery ischemia （MCAI） and ischemia reperfusion （IR） were created. In which, group A was subdivided into subgroups of isehemia for 1, 3, 6, lg, 24, and 48 h groups,i, e. groups A1-A6; those in group B, recanalization after one hour of ischemia, and were reperfused for 0, 2, 5, 11, 23, and 47 h, i.e. groups B1- B6. Apoptosis of the rabbit brains were detected immediately after each time point of MRI examination. Results In group A, the hyper-intensity area in MRI DWI increased gradually, and tended to stable at 24 h of ischemia; the rADC value decreased at first, and then increased. In group B, the rADC value increased at 2-h point with shrinkage of hyper-intensity area and decreased at 5 h point. After that, the rADC value rose again with enlargement of DWI hypePintensity area. The number of apnptosis cells in group A increased and reached its peak at 12-h time point and then lowered gradualy. In group B, the number of apoptosis increased gradually, reaching its peak at 23 h of reperfusion, but its extent was lower that that in group B. Conclusion The occurrence of apoptosis and the degree of ischemia are related to the duration, but apoptosis is not associated with the variation of DDC value.
出处
《青岛大学医学院学报》
CAS
2010年第1期35-38,共4页
Acta Academiae Medicinae Qingdao Universitatis
关键词
磁共振成像
弥散
脑缺血
细胞凋亡
nuclear magnetic resonance, diffusion
cerebral ischemia
apoptosis
作者简介
刘珍友（1971-），女，硕士研究生。
