低灌注兔模型脑血流动力学的多层螺旋CT灌注成像研究

目的探讨多层螺旋CT在实验性低灌注兔模型脑血流动力学研究中的价值。方法健康新西兰大白兔16只,随机分成正常对照组6只及低灌注模型组10只。采用结扎双侧颈总动脉及右侧椎动脉的方法,创建实验性低血流灌注模型。所有兔在术后4~6小时行CT平扫选择显示上矢状窦最大的两个层面,经股静脉以2ml/s速率注入造影剂行头颅CT灌注扫描,经后处理获得灌注图像。对感兴趣区平均脑血流量、平均脑血容量及达峰时间等血流动力学参数进行测量与分析。取兔脑与CT灌注扫描相对应层面的切片行HE染色。结果低灌注模型组大白兔脑组织CBV为(20.43±2.88)ml·100mg-1,CBF为(45.75±9.96)ml·min-1·100mg-1,TP为(2.61±0.29)s;正常对照组CBV为(33.37±11.06)ml·100mg-1,CBF为(58.85±20.58)ml·min-1·100mg-1,TP为(2.08±0.20)s;统计学分析表明,两组研究对象间的三个参数均具有显著性差异,且TP对低灌注模型组脑血流动力学参数变化的反映更加敏感。结论结扎双侧颈总动脉及单侧椎动脉制作兔低血流灌注模型稳定可靠。经股静脉团注对比剂行CT灌注扫描可较敏感地反映低灌注模型脑组织的血流动力学状态,为缺血性脑梗死的早期预防和诊断、治疗提供重要信息。

CT perfusion imaging on the hemodynamics of rabbit model with cerebral hypoperfusion

Objection To investigate the value of CT perfusion imaging in the hemodynamics of experimental rabbit model with cerebral hypoperfusion. Methods Sixteen New Zealand rabbits were classified randomly into 2 groups: one was control group (n=6) and the other was cerebral hypoperfusion group (n=10). The group of experimental cerebral hypoperfusion models was created by occlusion of the bilateral internal carotid artery (IAC) and the right vertebral artery (VA). In 4-6 hours after operation, all the rabbits were performed the CT examination to choose two slices showing the superior sagittal sinus better and then underwent the CTPI. The injection rate of contrast medium was 2 ml/s by the femoral vein. Study on the hemodynamics parameters includes CBV, CBF and TP of the ROI. The slices were performed HE staining according to those of the CTPI. Results The CBV, CBF and TP of rabbit model with cerebral hypoperfusion was (20.43±2.88) ml·100 mg^-1, (45.75±9.96) ml·min^-1·100 mg^-1, and (2.61±0.29) s, respectively; the CBV, CBF and TP of the control was (33.37±11.06) ml·100 mg^-1, (58.85±20.58) ml·min^-1·100 mg^-1, and (2.08±0.20) s respectively; there was significantly defferences between the two groups in the three parameters. Conclusion It is stable to get the model with hypoperfusion by occlusion of the bilateral IAC and unilateral VA. CTPI can sensitively reveal the cerebral hemodynamics of the rabbit model with hemoperfusion, which could provide the important information for the early prevention, diagnosis and treatment of cerebral ischemia.