研究介入法血栓栓塞犬大脑中动脉（MCA）建立脑梗死模型的可行性、稳定性及急性期在磁共振扩散加权成像（DWI）上的演变过程，并探讨该模型的发生及其可能的发病机制。

成年健康毕格犬6只，插管至左侧颈内动脉后采用1条直径约1.7 mm、长5 mm的白色血栓栓塞，栓塞成功后30 min～6 h内每30 min使用DWI序列连续扫描观察梗死病灶急性期的演变过程。栓塞后24 h、7天复查血管造影、MR扫描及神经功能评分，记录梗死灶的出现时间、位置及大小，分别比较6 h DWI病灶、24 h和7天的T2加权像上病灶的体积，并比较24 h与7天的神经功能评分。7天后处死动物取脑组织行病理检查。

所有犬皆为左侧MCA的近端栓塞，DWI在栓塞后(1.24±0.51)h可以在基底节、脑白质区显示单一或数个异常信号病灶，6 h DWI病灶的直径为(6.90±2.08)mm。共有9个病灶在三个时间点都可以显示，病灶的大小均<10 mm；栓塞后6 h DWI，24 h T2WI以及7 d T2WI病灶体积分别为(168.39±138.11)mm3、(186.88±161.54)mm3和(165.89±135.30)mm3，三者之间差异无明显统计学意义（P=0.0531）。7 d时动物均存活，24 h和7 d的神经功能评分分别为4.50±1.38和2.33±0.82（P=0.0009）。病理学检查证实为基底节梗死最常见，其次为脑白质区。

介入单栓子栓塞法可以成功建立犬MCA近端栓塞的类腔隙性脑梗死模型，DWI能够在早期检测到小的脑缺血病灶。犬拥有丰富的颅内外血管吻合，近端大血管栓塞可形成类腔隙性脑梗死的病灶，因此栓塞可能是腔隙性脑梗死的病因之一。

To evaluate the feasibility, stability and process on diffusion weighted imaging (DWI) in acute phase of a middle cerebral artery (MCA) embolic occlusion stroke model in beagle dogs, and to discuss the potential mechanisms of lacunar infarction.

Six adult beagle dogs were involved in this study. After the catheterization was manipulated into the left internal carotid artery, an autologous clot about 1.7 mm in diameter and 5 mm long was injected through the catheter in each dog. The DWI was performed to evaluate the progression of ischemic lesions at 30 min interval within 6 h after embolization. The MR examinations with the same parameters and neurobehavioral scoring were performed at 24 h and 7 days after procedure. These animals were sacrificed for pathological examination at 7 days after embolization.

The left proximal MCA ware successfully occluded in all dogs using single-thrombus method. The solitary or multiple ischemic lesions shown as high signal intensity on DWI were observed with the mean detecting time of (1.22±0.51)h in the deep brain area, and the mean diameter of induced infarctions was (6.90±2.08)mm on 6 h-DWI after embolization. The mean volume of these lesions was (168.39±138.11)mm3, (186.88±161.54)mm3 and (165.89±135.30)mm3 at 6 h on DWI, 24 h and 7 days on T2 image, respectively. The statistical analysis didn’t show significant difference in the volume among the three time points (P=0.0531). The neuro-behavioral scores were 4.50±1.38 at 24 h and 2.33±0.82 at 7 days after procedure (P=0.0009). The ischemic infarctions located in the basilar ganglion area were most frequent in pathological examination.

The DWI abnormalities resembling lacunar infarcts can be detected in early phase after reliable proximal MCA occlusion using thrombi in beagle dogs, which exist abundant collateral anastomosis between the ECA and ICA. Our results provide further support for the concept that emboli may be a potential cause of lacunar infarcts.