Objectives

To assess the feasibility of quantitative analysis of dynamic computed tomography angiography (dCTA) for the detection of endoleaks in patients who underwent endovascular repair of abdominal aortic aneurysms (EVAR).

Material and methods

Twenty patients scheduled for contrast-enhanced CT angiography (CTA) of the abdominal aorta post-EVAR were prospectively enrolled. All patients received a standard triphasic CTA protocol, followed by an additional dCTA. The dCTA acquisition enabled reconstruction of color-coded maps depicting blood perfusion and a dCTA dataset of the aneurysm sac. Observers assessed the dCTA and dynamic CT perfusion (dCTP) images for the detection of endoleaks, establishing diagnostic confidence based on a modified 5-point Likert scale. An index was calculated for the ratio between the endoleak and aneurysm sac using blood flow for dCTP and Hounsfield units (HU) for dCTA. The Wilcoxon test compared the endoleak index and the diagnostic confidence of the observers.

Results

In total, 19 patients (18 males, median age 74 years [70.5–75.7]) were included for analysis. Nine endoleaks were detected in 7 patients using triphasic CTA as the reference standard. There was complete agreement for endoleak detection between the two techniques on a per-patient basis. Both dCTA and dCTP identified an additional endoleak in one patient. The diagnostic confidence using dCTP for detection of endoleaks was not significantly superior to dCTA (5.0 [5–5] vs. 4.5 [4–5], respectively; p = 0.11); however, dCTP demonstrated superior diagnostic confidence for endoleak exclusion compared to dCTA (1.0 [1–1] vs 1.5 [1.5–1.5], respectively; p <0.01). Moreover, the dCTP endoleak index was significantly higher than the dCTA index (18.5 [10.8–20.5] vs. 3.5 [5–2.7], respectively; p = 0.02).

Conclusions

Quantitative analysis of dCTP imaging can aid in the detection of endoleaks and demonstrates a higher endoleak detection rate than triphasic CTA, as well as a strong correlation with visual assessment of dCTA images.

中文翻译：

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动态计算机断层扫描血管造影定量分析以检测腹主动脉瘤腔内修复术后内漏的可行性研究

目标

评估动态计算机断层血管造影术（dCTA）定量分析进行腹主动脉瘤（EVAR）血管内修复的患者内渗漏的可行性。

材料与方法

前瞻性纳入了计划在EVAR后进行腹主动脉造影增强CT血管造影（CTA）的20例患者。所有患者均接受标准的三重CTA方案，然后再加dCTA。dCTA采集能够重建描绘血液灌注的彩色编码图和动脉瘤囊的dCTA数据集。观察者评估了dCTA和动态CT灌注（dCTP）图像以检测内漏，并基于修改后的5点Likert量表建立了诊断置信度。使用dCTP的血流和dCTA的Hounsfield单位（HU）来计算内漏和动脉瘤囊之间的比率的指数。Wilcoxon测试比较了内漏指数和观察者的诊断置信度。

结果

总共包括19例患者（男18例，中位年龄74岁[70.5-75.7]）进行分析。使用三相CTA作为参考标准，在7例患者中检测到9种内漏。两种技术之间基于患者的内漏检测完全一致。dCTA和dCTP均在一名患者中发现了另一种内渗。使用dCTP检测内漏的诊断置信度没有明显优于dCTA（分别为5.0 [5-5]和4.5 [4-5]； p = 0.11）；然而，与dCTA相比，dCTP表现出对内漏排除的更高诊断置信度（分别为1.0 [1-1]与1.5 [1.5-1.5]； p <0.01）。此外，dCTP内漏指数显着高于dCTA指数（分别为18.5 [10.8-20.5]与3.5 [5-2.7]； p = 0.02）。

结论

dCTP成像的定量分析可以帮助检测内漏，并显示出比三相CTA高的内漏检测率，并且与dCTA图像的视觉评估有很强的相关性。