多参数高场强磁共振成像评估恒河猴急性脑梗死血栓-溶栓模型

High-field magnetic resonance imaging with multiple parameters to evaluate the thrombus-thrombolysis model in rhesus monkeys with acute cerebral infarction

目的使用高场强磁共振成像(magnetic resonance imaging,MRI)对非人灵长类动物(nonhuman primates,NHPs)急性脑梗死血栓-溶栓模型进行评价。方法 8只成年雄性恒河猴,年龄(8.2±1.2)岁,体重(9.4±1.0)kg,随机分为梗死组(n=4)和溶栓组(n=4),采用恒河猴自体血栓制备大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型(M1段),栓塞后,溶栓组给予rt-PA溶栓治疗,梗死组仅接受等量生理盐水。分别于术后4 h和24 h进行磁共振T2WI、T2-FLAIR、TOF-MRA、DWI扫描。结果成功制备恒河猴血栓-溶栓模型。MRA显示梗死组大脑中动脉(middle cerebral artery,MCA)均未再通,溶栓组MCA实现血管再通。T2WI序列显示梗死组梗死体积增量为(12 027±5507)mm3,溶栓组梗死体积增量为(4910±2764)mm3;DWI序列显示梗死组梗死体积增量为(9498±5226)mm3,溶栓组梗死体积增量为(4854±1792)mm3。T2WI和DWI序列均显示,两组4 h梗死体积比较,差异无显著性;溶栓组24 h梗死体积低于梗死组,差异有显著性;溶栓组的梗死体积增量低于梗死组,差异有显著性。结论应用MRI序列成功评估恒河猴血栓-溶栓模型的再通及梗死灶变化。

Objective To examine the nonhuman primate（NHP） model of acute cerebral infarction thrombusthrombolysis using multi-parameter high-field magnetic resonance imaging（MRI）. Methods Altogether,8 adult male rhesus monkeys aged 8. 2（± 1. 2） years old and weighing 9. 4（± 1. 0） kg were randomized into an infarction group（n= 4） and thrombolysis group（n = 4）. Middle cerebral artery occlusion（MCAO） was induced with a clot in the M1 segment. Monkeys in the thrombolysis group were treated with the recombinant tissue plasminogen activator,rt-PA,whilethose in the infarction group were treated with 0. 9% Na Cl only. T2 weighted imaging（T2 WI）,T2-weighted-fluidattenuated inversion recovery（T2-FLAIR）,time-of-flight magnetic resonance angiography（TOF-MRA）,and diffusionweighted imaging（DWI） were used to examine all monkeys at 4 and 24 h after onset of ischemia. Results The rhesus monkey thrombus-thrombolysis model was successfully established. MRA showed that the middle cerebral artery（MCA）was not recanalized in the infarction group,but was recanalized in the thrombolysis group. T2 WI sequence showed an increase in infarction volume（12 027 ± 5507 mm^3） in the infarction group compared with the thrombolysis group（4910 ±2764 mm^3）. DWI sequence showed an increase in infarction volume（9498 ± 5226 mm^3） in the infarction group and thrombolysis group（4854 ± 1792 mm^3）. Both T2 WI and DWI sequences showed no significant difference in infarction volume at 4 h between the two groups,while infarction volume in the thrombolysis group at 24 h was significantly lower compared with the infarction group. The increase in infarction volume was significantly lower in the thrombolysis group compared with the infarction group. Conclusions MRI sequences can be used to successfully evaluate recanalization and infarct changes in the thrombus-thrombolysis model in rhesus monkeys.