Duke Cardiovascular Magnetic Resonance Center, Duke University Medical Center, DUMC-3934, Durham, NC, 27710, USA.
Division of Cardiology, Duke University Medical Center, Durham, NC, USA.
Eur Radiol. 2021 Jul;31(7):5087-5095. doi: 10.1007/s00330-020-07408-1. Epub 2021 Jan 6.
Cardiac motion and aortic pulsatility can affect the image quality of 3D contrast-enhanced MR angiography (CE-MRA). The addition of ECG gating improves image quality; however, no studies have directly linked image quality improvements to clinically used measures. In this study, we directly compared diameter measurements in the same patient from ECG-gated to non-gated CE-MRA to evaluate the impact of ECG gating upon measurement reproducibility.
Fifty-three patients, referred for thoracic aortic angiography, were enrolled and underwent both non-gated and ECG-gated CE-MRA. Two readers independently measured vessel diameter, image quality, and vessel sharpness at the sinus of Valsalva (SOV), sinotubular junction (STJX), ascending aorta (AAO), distal aortic arch (DLSA), and descending aorta (DAO). Measurement reliability and reproducibility were compared between methods.
Image quality with ECG gating was rated significantly higher at the SOV (3.2 ± 0.9 vs 1.2 ± 1.0, p < 0.0001), STJX (3.4 ± 0.7 vs 1.8 ± 1.0, p < 0.0001), AAO (3.5 ± 0.6 vs 1.7 ± 1.1 p < 0.0001), DLSA (4.0 ± 0.1 vs 3.6 ± 0.7, p = 0.006), and DAO (4.0 ± 0.1 vs 3.4 ± 0.9 p < 0.0001) than for non-gated studies. Bland-Altman analyses demonstrated that inter- and intra-observer variability was significantly smaller for ECG-gated MRA at the SOV and AAO. For the non-gated images at the SOV, the 95% limits of agreement for both inter- and intra-observer variability exceeded the growth-rate cutoff for surgical repair (0.5 cm). At the DAO, variability was similar between the two techniques.
ECG-gated CE-MRA resulted in improved reproducibility in aortic root and ascending aortic measurements. These data suggest that ECG-gated CE-MRA should be used for the serial assessment of the ascending thoracic aorta.
• ECG-gated CE-MRA improves the reproducibility and repeatability of measurements of the ascending aorta. • With non-gated CE-MRA, pulsatile motion in the proximal aorta results in significant variability in measurement reproducibility.
心脏运动和主动脉脉动性会影响三维对比增强磁共振血管成像（CE-MRA）的图像质量。添加心电图门控可改善图像质量；然而，尚无研究直接将图像质量改善与临床使用的测量方法联系起来。在这项研究中，我们直接比较了同一患者心电图门控与非门控 CE-MRA 的直径测量值，以评估心电图门控对测量可重复性的影响。
53 名因胸主动脉造影而就诊的患者入组并接受了非门控和心电图门控 CE-MRA。两位读者独立测量窦管交界（SOV）、窦管交界（STJX）、升主动脉（AAO）、远端主动脉弓（DLSA）和降主动脉（DAO）处的血管直径、图像质量和血管锐利度。比较两种方法的测量可靠性和可重复性。
SOV（3.2±0.9 对 1.2±1.0，p＜0.0001）、STJX（3.4±0.7 对 1.8±1.0，p＜0.0001）、AAO（3.5±0.6 对 1.7±1.1，p＜0.0001）、DLSA（4.0±0.1 对 3.6±0.7，p=0.006）和 DAO（4.0±0.1 对 3.4±0.9，p＜0.0001）的心电图门控图像质量评分明显高于非门控研究。Bland-Altman 分析表明，SOV 和 AAO 处的心电图门控 MRA 具有更小的观察者间和观察者内变异性。在 SOV 的非门控图像中，观察者间和观察者内变异性的 95%一致性界限超过了手术修复的生长率截止值（0.5cm）。在 DAO 处，两种技术之间的变异性相似。
心电图门控 CE-MRA 提高了主动脉根部和升主动脉测量的可重复性。这些数据表明，心电图门控 CE-MRA 应用于升主动脉的连续评估。
•心电图门控 CE-MRA 提高了升主动脉测量的可重复性和可重复性。•非门控 CE-MRA 时，近端主动脉的搏动运动导致测量重复性的显著变化。
