CTA多期动态重建显示腹主动脉夹层内膜搏动的应用价值

The value of multiphase dynamic reconstruction with CTA to the intimal flap motion of abdominal aortic dissection

目的探讨低剂量回顾性心电门控CTA多期相动态重建对显示腹主动脉夹层内膜搏动的应用价值。方法腹主动脉夹层患者30例行光子CT低剂量回顾性心电门控扫描,从0%-95%R-R间期每隔5%进行图像重建,测量20期图像中腹腔干、肠系膜上动脉、左右肾动脉根部水平真腔短轴直径和相应水平腹主动脉直径,计算两者比值（d-T/d-AA）、真腔/腹主动脉（d-T/d-AA）的最大值、最小值和位于70%R-R间期时两者的比值;比较三者之间有无差异,间接找出评价内膜搏动范围。结果腹腔干、肠系膜上动脉水平内膜搏动范围较大,在70%R-R、d-T/d-AA的最大值、最小值之间均有明显变化,左右肾动脉水平内膜在d-T/d-AA最大值与最小值期相之间搏动明显,在70%R-R与d-T/d-AA最大、最小值期相之间搏动弱,变化不明显。有效辐射剂量（16.1±2.19）m Sv。结论低剂量回顾性心电门控CTA多期动态重建能良好地显示腹主动脉夹层内膜搏动的情况。

Objective To explore the value of lowdose of multiphase dynamic reconstruction using retrospective ECG gated CTA to the intimal flap motion of abdominal aortic dissection. Methods Thirty patients with abdominal aortic dissection underwent with retrospective ECG gated double source CT（ DSCT）,and 20 datasets were reconstructed in5% steps between 0 and 95% of the R-R interval in each case. The short axis diameter of the true lumen and abdominal aorta in the level of the root of celiac and superior mesenteric artery,left renal artery and right renal artery in each phase were measured,and the ratio of both（ d- T/ d- AA） was calculated. The ratio of the minimum and maximum as well as70% R-R intervals was calculated and the three statistical difference for evaluating the intimal flap indirectly was compared. Results The scope of intimal flap was strong in the level of celiac and superior mesenteric artery,and intimal flap was significantly changed between 70% R-R,the maximum and the minimum. Intimal flap was significantly changed between the maximum and minimum in the level of right renal artery and left renal artery. The scope of intimalflap was weak between 70% R-R and the maximum as well as between 70% R-R and the minimum. The changes was not obvious. Conclusion Lowdose of multiphase dynamic reconstruction using retrospective ECG gated CTA can showthe intimal flap motion of abdominal aortic dissection.