中文摘要：

目的 评价70 kV管电压低剂量扫描在兔脑CT灌注成像的可行性.方法 健康新西兰大白兔20只,每只兔分别使用70、80 kV管电压行兔脑CT灌注检查,两次检查间隔时间为24 h.比较两组方案有效剂量（E）、脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）及图像质量指标信噪比（SNR）.结果 70与80 kV组兔脑CT灌注的有效剂量分别为1.91和2.93 mSv,70 kV组较80 kV组减少约34.8％.两组扫描所测量脑灌注参数CBF、CBV、MTT间的差异无统计学意义.两组测量的SNR分别为（23.15±5.98）和（21.23±9.18）,差异无统计学意义.结论 使用70 kV管电压行兔脑CT灌注成像可降低有效剂量,而对灌注参数结果及图像质量无明显影响.

英文摘要：

Objective To evaluate the feasibility of low dose CT perfusion imaging of brain using the tube voltage of 70 kV.Methods Twenty New Zealand white rabbits underwent cerebral CT perfusion imaging with tube voltage 70 and 80 kV separately,and the interval between two scans was 24 h.The effective dosage （E）,cerebral perfusion parameters （CBF,CBV,MTT） and image quality indicator （SNR） of middle cerebral artery of each protocol were acquired and compared statistically.Results The effective dosage of70 kV group was 1.91 mSv,34.8％ lower than that of 80 kV group with the dose of 2.93 mSv.There were no significant differences between the cerebral perfusion parameters acquired at different corresponding ROI.SNR of 70 kV group and 80 kV group were （23.15 ± 5.98） and （21.23 ±9.18） with no significantly statistical difference.Conclusions The effective dosage of 70 kV cerebral CT perfusion imaging could be dramatically reduced with no significant influence on the results of perfusion parameters and image quality.