双源CT心电门控与非门控Flash扫描主动脉成像的对照研究

Comparison of Non-ECG-Gated and Gated Flash Mode of Dual-Source CT in Aorta Angiography

目的比较双源CT非心电门控与心电门控Flash扫描主动脉CT血管造影（CTA）的图像质量和辐射剂量,探讨其应用价值。方法将40例临床可疑主动脉疾病或主动脉夹层、动脉瘤术后行主动脉CTA检查的患者随机分成两组,A组采用非心电门控Flash扫描,B组采用心电门控Flash扫描,分别测量两组右无名动脉CT值、升主动脉CT值、降主动脉CT值、腹主动脉CT值、脊柱旁肌肉CT值和噪声,并计算信噪比（SNR）及对比噪声比（CNR）,比较两组各动脉的CT值、噪声、SNR、CNR、扫描时间、图像质量及有效辐射剂量（ED）差异。结果两组扫描时间和ED比较差异有统计学意义（P〈0.05）;5个测量部位CT值比较差异均无统计学意义（t值=-0.44、-0.12、-0.54、-0.32、-1.62,P〉0.05）,5个测量部位噪声、SNR及CNR比较差异均有统计学意义（t值=-7.03、-4.96、-4.69、-5.34、-3.20,P〈0.05;t值=4.81、3.64、3.17、3.61、2.05,P〈0.05;t值=4.49、3.44、3.02、3.35、1.86,P〈0.05）;图像质量比较差异无统计学意义（P〉0.05）,但B组图像优良率高于A组。结论双源CT非心电门控与心电门控Flash扫描主动脉CTA均能获得满足诊断的优质图像,其中心电门控Flash扫描可进一步缩短扫描时间、降低辐射剂量,对冠状动脉开口的显示更佳。

Objective To compare the image quality and radiation dose of dual-source CT non-electrocardiography gating and ECG-gated flash scanning with aortic CTA imaging,and to explore its application value.Methods 40 patients with suspected clinical aortic diseases or aortic dissection and aortic aneurysm undergoing aortic CTA examination were randomly divided into 2 groups.Non-cardiac gated flash scan was used in group A and ECG gated flash scan was used in group B.The CT values,noise,and CT values of the right innominate artery,ascending aorta,descending aorta,and abdominal aorta were measured,and the signal-to-noise ratio（SNR） and the contrast signal-to-noise ratio（CNR） were calculated.CT values,noise,SNR,CNR,scan time,image quality,and effective radiation dose（ED） difference for each artery in the group.Results There were significant differences in the scan time and ED between the two groups（t value = 30.25,P= 0.000;t = 14.17,P = 0.000）;there was no significant difference in the CT values of the five measurement sites（t =-0.44,-0.12,-0.54,-0.32,-1.62,P〉0.05）,There were statistically significant differences in noise,SNR,and CNR at the five measurement locations（t =-7.03,-4.96,-4.79,-5.34,-3.20,P〈0.05;t = 4.81,3.64,3.17,3.61,2.05,P〈0.05;t = 4.49,3.44,3.02,3.35,1.86,P〈0.05）;no statistical difference in image quality Significance（P〉0.05）,but the excellent rate of group B images is higher than that of group A.Conclusion Both dual-source CT non-electrocardiographic gating and ECG-gated flash aortic CTA can obtain high-quality images that meet the diagnosis.The central electric gated flash scan can further shorten the scan time and reduce the radiation dose,and can be used to open coronary arteries.The display is better.