Lu Chun-Yan, Diao Yi-Ke, Guo Ying-Qiang, Zhang Xiao-Hui, Bai Hong-Li, Li Zhen-Lin
1 Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
2 Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
Acta Radiol. 2018 Jan;59(1):58-64. doi: 10.1177/0284185117704236. Epub 2017 Apr 25.
Background Acute aortic dissection (AD) is a life-threatening medical emergency. It has been debated whether the multiphase dynamic computed tomography angiography (CTA) protocol is superior to the standard triphasic protocol for revealing the characteristics of AD. Purpose To examine two multiphase dynamic protocols, Dynamic four-dimensional (4D) CTA using the shuttle mode and Flash 4D CTA using the high-pitch mode for the assessment of AD and to compare them with the standard triphasic protocol. Material and Methods A total of 54 consecutive patients were randomly and equally assigned to three groups and scanned with a second-generation DSCT scanner. Groups A, B, and C were assessed with the Dynamic 4D CTA in the shuttle mode, the Flash 4D CTA in the high-pitch mode, and the standard triphasic acquisition protocol, respectively. Image quality of all patients was evaluated. The effective radiation dose (ED) was recorded. Results In 54 patients, CTA images could display the true and false lumens, the intimal flap, the entry tear, and branch vessel involvement in the AD. Compared with group C, additional diagnostic information was obtained in groups A and B, including the dynamic enhancement delay between the true and false lumens (A = 18, B = 18); the presence of membrane oscillation (A = 8, B = 14); dynamic ejection of the contrast material from the true lumen into the false lumen (A = 6, B = 7); and the dynamic obstruction of the left renal artery (B = 2). The ED in these three groups was significantly different ( P < 0.05). Conclusion Compared to the standard triphasic protocol, the multiphase dynamic CTA protocol is feasible and is able to reveal additional diagnostic information. Therefore, we recommend using the high-pitch, dual-source multiphase dynamic CTA to assess ADs.
背景 急性主动脉夹层（AD）是一种危及生命的医疗急症。多期动态计算机断层扫描血管造影（CTA）方案在揭示AD特征方面是否优于标准三期方案一直存在争议。目的 研究两种多期动态方案，即使用穿梭模式的动态四维（4D）CTA和使用高螺距模式的Flash 4D CTA用于评估AD，并将它们与标准三期方案进行比较。材料与方法 总共54例连续患者被随机且等分为三组，并用第二代双源CT扫描仪进行扫描。A组、B组和C组分别采用穿梭模式的动态4D CTA、高螺距模式的Flash 4D CTA和标准三期采集方案进行评估。评估所有患者的图像质量。记录有效辐射剂量（ED）。结果 在54例患者中，CTA图像能够显示AD的真假腔、内膜瓣、入口撕裂和分支血管受累情况。与C组相比，A组和B组获得了额外的诊断信息，包括真假腔之间的动态强化延迟（A组 = 18例，B组 = 18例）；膜振荡的存在（A组 = 8例，B组 = 14例）；对比剂从真腔向假腔的动态喷射（A组 = 6例，B组 = 7例）；以及左肾动脉的动态阻塞（B组 = 2例）。这三组的ED有显著差异（P < 0.05）。结论 与标准三期方案相比，多期动态CTA方案是可行的，并且能够揭示额外的诊断信息。因此，我们建议使用高螺距双源多期动态CTA来评估AD。
