Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
Eur Radiol. 2020 Nov;30(11):5794-5804. doi: 10.1007/s00330-020-06963-x. Epub 2020 Jun 7.
Assessment of thoracic aortic dimensions with non-ECG-triggered contrast-enhanced magnetic resonance angiography (CE-MRA) is accompanied with motion artefacts and requires gadolinium. To avoid both motion artefacts and gadolinium administration, we evaluated the similarity and reproducibility of dimensions measured on ECG-triggered, balanced steady-state free precession (SSFP) MRA as alternative to CE-MRA.
All patients, with varying medical conditions, referred for thoracic aortic examination between September 2016 and March 2018, who underwent non-ECG-triggered CE-MRA and SSFP-MRA (1.5 T) were retrospectively included (n = 30). Aortic dimensions were measured after double-oblique multiplanar reconstruction by two observers at nine landmarks predefined by literature guidelines. Image quality was scored at the sinus of Valsalva, mid-ascending aorta and mid-descending aorta by semi-automatically assessing the vessel sharpness.
Aortic dimensions showed high agreement between non-ECG-triggered CE-MRA and SSFP-MRA (r = 0.99, p < 0.05) without overestimation or underestimation of aortic dimensions in SSFP-MRA (mean difference, 0.1 mm; limits of agreement, - 1.9 mm and 1.9 mm). Intra- and inter-observer variabilities were significantly smaller with SSFP-MRA for the sinus of Valsalva and sinotubular junction. Image quality of the sinus of Valsalva was significantly better with SSFP-MRA, as fewer images were of impaired quality (3/30) than in CE-MRA (21/30). Reproducibility of dimensions was significantly better in images scored as good quality compared to impaired quality in both sequences.
Thoracic aortic dimensions measured on SSFP-MRA and non-ECG-triggered CE-MRA were similar. As expected, SSFP-MRA showed better reproducibility close to the aortic root because of lesser motion artefacts, making it a feasible non-contrast imaging alternative.
• SSFP-MRA provides similar dimensions as non-ECG-triggered CE-MRA. • Intra- and inter-observer reproducibilities improve for the sinus of Valsalva and sinotubular junction with SSFP-MRA. • ECG-triggered SSFP-MRA shows better image quality for landmarks close to the aortic root in the absence of cardiac motion.
使用非心电图触发对比增强磁共振血管造影（CE-MRA）评估胸主动脉的尺寸会伴有运动伪影并需要钆剂。为了避免运动伪影和钆剂的使用，我们评估了心电图触发、平衡稳态自由进动（SSFP）MRA 测量的尺寸的相似性和可重复性，以此作为 CE-MRA 的替代方法。
回顾性纳入 2016 年 9 月至 2018 年 3 月期间因胸主动脉检查而接受非心电图触发 CE-MRA 和 SSFP-MRA（1.5T）的不同医疗条件的所有患者（n=30）。通过两位观察者在文献指南预定义的九个标志点进行双斜多平面重建后测量主动脉尺寸。通过半自动评估血管锐利度对窦部、升主动脉中段和降主动脉中段进行图像质量评分。
非心电图触发 CE-MRA 和 SSFP-MRA 之间的主动脉尺寸具有高度一致性（r=0.99，p<0.05），SSFP-MRA 中主动脉尺寸没有高估或低估（平均差异，0.1mm；一致性界限，-1.9mm 和 1.9mm）。对于窦部和窦管交界，SSFP-MRA 的观察者内和观察者间变异性明显更小。SSFP-MRA 的窦部图像质量明显更好，因为与 CE-MRA（21/30）相比，窦部图像质量受损的图像更少（3/30）。在两种序列中，评分良好的图像的尺寸可重复性明显优于质量受损的图像。
SSFP-MRA 和非心电图触发 CE-MRA 测量的胸主动脉尺寸相似。如预期的那样，由于运动伪影较小，SSFP-MRA 接近主动脉根部的可重复性更好，使其成为一种可行的非对比成像替代方法。
SSFP-MRA 提供与非心电图触发 CE-MRA 相似的尺寸。
对于窦部和窦管交界，SSFP-MRA 提高了观察者内和观察者间的可重复性。
在没有心脏运动的情况下，心电图触发的 SSFP-MRA 对主动脉根部附近的标志点具有更好的图像质量。
