对比超声评价急性脑缺血对犬脑组织血流灌注的影响  

Effects of acute cerebral ischemia on cerebral perfusion: quantitative evaluation by contrast-enhanced ultrasound in dogs

作　　者：曾平[1,2] 孙学刚[3] 查道刚[4] 宾建平[4] 周颖玲[1,2] 陈勇驰[1,2] 刘伊丽[4] 

机构地区：[1]广东省人民医院 [2]广东省医学科学院老年医学研究所心内科,广东广州510080 [3]南方医科大学中医药学院分子生物学实验室,广东广州510515 [4]南方医科大学南方医院心内科,广东广州510515

出　　处：《南方医科大学学报》2010年第7期1518-1521,共4页Journal of Southern Medical University

基　　金：国家自然科学基金(30370589)

摘　　要：目的应用对比超声(CEU)定量评价急性脑缺血对脑组织血流灌注的影响。方法健康杂种犬6条,左侧顶骨开窗。动脉夹夹闭左颈总动脉(LCCA)后即刻、30、60、90及120min后行声学造影。对图像进行脱机分析,得出不同时间点左右大脑皮质相应的脑组织微循环血管容积(A)、血流速度(β)及血流量(A×β)。以右侧颈总动脉血流及犬头部SPECT扫描与CEU结果相对照。结果 CEU估测脑血流量(CBF)与颈动脉血流量具有良好相关性。夹闭LCCA后同一大脑半球前后不同时间点之间及双侧大脑半球同一时间点之间A、β及A×β均有显著性差异(P<0.001)。夹闭侧大脑半球即刻出现缺血性低灌注,对侧大脑半球出现充血性高灌注,120min后两侧大脑半球CBF基本一致。结论对比超声实现了实时观察犬一侧颈总动脉夹闭后时双侧大脑半球CBF的动态变化过程,血流速度β可能是急性脑缺血时CBF变化的主要调节因素。Objective To evaluate the changes of cerebral blood flow （CBF） with real-time contrast-enhanced ultrasound （CEU） in a canine model of acute cerebral ischemia. Methods Cerebral perfusion was assessed in 6 dogs subjected to craniotomy with CEU at the time of 0, 30, 60, 90 and 120 min after occlusion of the left common carotid artery （LCCA）. The microvascular volume （A） and blood flow velocity （β） in the brain were measured from the time-versus-acoustic intensity plots, and the value of A×β were calculated. 99mTc-ECD brain single photon emission computed tomography （SPECT） was performed on the day before the experiment and at 120 min after LCCA occlusion. The radioactive counts on both sides of the cerebral cortex were calculated. Results A significant correlation was found between A×β from CEU and volume of the blood flow of the CCA from Doppler flowmetry. A, β and A×β values varied significantly between the different time points （P0.001）. The ipsilateral hemisphere showed a low-perfusion state while the contralateral hemisphere showed a high-perfusion state immediately after the occlusion. Conclusions The changes of β is the main regulation mechanism during acute cerebral ischemia in dogs.

关 键 词：对比超声 脑缺血 脑组织血流灌注 

分 类 号：R445.1[医药卫生—影像医学与核医学]