Poskaite Paulina, Pamminger Mathias, Kranewitter Christof, Kremser Christian, Reindl Martin, Reiter Gert, Piccini Davide, Dumfarth Julia, Henninger Benjamin, Tiller Christina, Holzknecht Magdalena, Reinstadler Sebastian J, Klug Gert, Metzler Bernhard, Mayr Agnes
University Clinic of Radiology, Medical University of Innsbruck, Anichstraße 35, A-6020 Innsbruck, Austria.
University Clinic of Radiology, Medical University of Innsbruck, Anichstraße 35, A-6020 Innsbruck, Austria.
Magn Reson Imaging. 2021 Feb;76:123-130. doi: 10.1016/j.mri.2020.12.003. Epub 2020 Dec 9.
To prospectively compare image quality and reliability of a non-contrast, self-navigated 3D whole-heart magnetic resonance angiography (MRA) sequence with contrast-enhanced computed tomography angiography (CTA) for sizing of thoracic aortic aneurysm (TAA).
Self-navigated 3D whole-heart 1.5 T MRA was performed in 20 patients (aged 67 ± 9 years, 75% male) for sizing of TAA; a subgroup of 18 (90%) patients underwent additional contrast-enhanced CTA on the same day. Subjective image quality was scored according to a 4-point Likert scale and ratings between observers were compared by Cohen's Kappa statistics. For MRA, subjective motion blurring and signal inhomogeneity was rated according to a 3-point scale, respectively. Objective signal inhomogeneity of MRA was quantified as standard deviation of the voxel intensities in a circular region of interest (ROI) placed in the ascending aorta divided by their mean value. Continuous MRA and CTA measurements were analyzed with regression and Bland-Altman analysis.
Overall subjective image quality as rated by two observers was 1 [interquartile range (IQR) 1-2] for self-navigated MRA and 1.5 [IQR 1-2] for CTA (p = 0.717). For MRA, perfect inter-observer agreement was found regarding presence of artefacts and subjective image sharpness (κ = 1). Subjective signal inhomogeneity agreed moderately between the observers (κ = 0.58, p = 0.007), however, it correlated strongly with objectively quantified inhomogeneity of the blood pool signal (r = 0.78, p < 0.0001). Maximum diameters of TAA as measured by self-navigated MRA and CTA showed very strong correlation (r = 0.99, p < 0.0001) without significant inter-method bias (bias -0.03 mm, lower and upper limit of agreement -0.74 and 0.68 mm, p = 0.749). Inter-observer correlation of aortic aneurysm as measured by MRA was very strong (r = 0.96) without significant bias (p = 0.695).
Self-navigated 3D whole-heart MRA enables reliable contrast- and radiation free aortic dilation surveillance without significant difference to standardized CTA while providing predictable acquisition time and offering excellent image quality.
前瞻性比较非增强、自导航三维全心磁共振血管造影（MRA）序列与对比增强计算机断层血管造影（CTA）在测量胸主动脉瘤（TAA）大小时的图像质量和可靠性。
对20例患者（年龄67±9岁，75%为男性）进行自导航三维全心1.5T MRA以测量TAA大小；18例（90%）患者的亚组在同一天接受了额外的对比增强CTA检查。主观图像质量根据4分李克特量表评分，观察者之间的评分通过科恩kappa统计量进行比较。对于MRA，主观运动模糊和信号不均匀性分别根据3分制进行评分。MRA的客观信号不均匀性通过将置于升主动脉的圆形感兴趣区域（ROI）内体素强度的标准差除以其平均值来量化。连续的MRA和CTA测量结果采用回归分析和布兰德-奥特曼分析。
两名观察者评定的总体主观图像质量，自导航MRA为1[四分位间距（IQR）1 - 2]，CTA为1.5[IQR 1 - 2]（p = 0.717）。对于MRA，观察者之间在伪影存在和主观图像清晰度方面达成了完美的一致性（κ = 1）。观察者之间主观信号不均匀性的一致性中等（κ = 0.58，p = 0.007），然而，它与血池信号的客观量化不均匀性密切相关（r = 0.78，p < 0.0001）。自导航MRA和CTA测量的TAA最大直径显示出非常强的相关性（r = 0.99，p < 0.0001），且方法间无显著偏差（偏差 - 0.03mm，一致性下限和上限为 - 0.74和0.68mm，p = 0.749）。MRA测量的主动脉瘤观察者间相关性非常强（r = 0.96），且无显著偏差（p = 0.695）。
自导航三维全心MRA能够可靠地进行无对比剂和无辐射的主动脉扩张监测，与标准化CTA相比无显著差异，同时提供可预测的采集时间并具有出色的图像质量。
