Department of Vascular and Endovascular Surgery, University Hospital Frankfurt Goethe University, Frankfurt am Main, Germany.
Personalised Biomedical Engineering Lab, Frankfurt University of Applied Sciences, Frankfurt am Main, Germany.
J Ultrasound Med. 2021 Nov;40(11):2391-2402. doi: 10.1002/jum.15622. Epub 2021 Jan 16.
The four-dimensional ultrasound (4D-US) enables imaging of the aortic segment and simultaneous determination of the wall expansion. The method shows a high spatial and temporal resolution, but its in vivo reliability is so far unknown for low-measure values. The present study determines the intraobserver repeatability and interobserver reproducibility of 4D-US in the atherosclerotic and non-atherosclerotic infrarenal aorta.
In all, 22 patients with non-aneurysmal aorta were examined by an experienced examiner and a medical student. After registration of 4D images, both the examiners marked the aortic wall manually before the commercially implemented speckle tracking algorithm was applied. The cyclic changes of the aortic diameter and circumferential strain were determined with the help of custom-made software. The reliability of 4D-US was tested by the intraclass correlation coefficient (ICC).
The 4D-US measurements showed very good reliability for the maximum aortic diameter and the circumferential strain for all patients and for the non-atherosclerotic aortae (ICC >0.7), but low reliability for circumferential strain in calcified aortae (ICC = 0.29). The observer- and masking-related variances for both maximum diameter and circumferential strain were close to zero.
Despite the low-measured values, the high spatial and temporal resolution of the 4D-US enables a reliable evaluation of cyclic diameter changes and circumferential strain in non-aneurysmal aortae independent from the observer experience but with some limitations for calcified aortae. The 4D-US opens up a new perspective with regard to noninvasive, in vivo assessment of kinematic properties of the vessel wall in the abdominal aorta.
四维超声（4D-US）能够对主动脉节段进行成像，并同时确定壁扩张。该方法具有较高的空间和时间分辨率，但对于低测量值，其体内可靠性尚不清楚。本研究旨在确定 4D-US 在动脉粥样硬化和非动脉粥样硬化肾下主动脉中的观察者内重复性和观察者间可重复性。
共对 22 例非动脉瘤性主动脉患者进行了检查，由一位有经验的检查者和一位医学生进行。在注册 4D 图像后，两位检查者在应用商用斑点跟踪算法之前手动标记主动脉壁。使用定制软件确定主动脉直径和周向应变的循环变化。通过组内相关系数（ICC）测试 4D-US 的可靠性。
4D-US 测量结果对于所有患者和非动脉粥样硬化主动脉的最大主动脉直径和周向应变均显示出非常好的可靠性（ICC>0.7），但在钙化主动脉中的周向应变可靠性较低（ICC=0.29）。观察者和掩蔽相关的方差对于最大直径和周向应变均接近零。
尽管测量值较低，但 4D-US 的高空间和时间分辨率能够可靠地评估非动脉瘤性主动脉的循环直径变化和周向应变，与观察者经验无关，但对于钙化主动脉存在一些限制。4D-US 为非侵入性、体内评估腹主动脉血管壁运动学特性开辟了新的视角。
