Stroud Robert E, Piccini Davide, Schoepf U Joseph, Heerfordt John, Yerly Jérôme, Di Sopra Lorenzo, Rollins Jonathan D, Fischer Andreas M, Suranyi Pal, Varga-Szemes Akos
Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA.
Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue de Bugnon 46, BH 7.84, 1010, Lausanne, Switzerland.
Eur Radiol Exp. 2019 Jul 31;3(1):29. doi: 10.1186/s41747-019-0107-4.
Whole-heart magnetic resonance angiography (MRA) requires sophisticated methods accounting for respiratory motion. Our purpose was to evaluate the image quality of compressed sensing-based respiratory motion-resolved three-dimensional (3D) whole-heart MRA compared with self-navigated motion-corrected whole-heart MRA in patients with known thoracic aorta dilation.
Twenty-five patients were prospectively enrolled in this ethically approved study. Whole-heart 1.5-T MRA was acquired using a prototype 3D radial steady-state free-precession free-breathing sequence. The same data were reconstructed with a one-dimensional motion-correction algorithm (1D-MCA) and an extradimensional golden-angle radial sparse parallel reconstruction (XD-GRASP). Subjective image quality was scored and objective image quality was quantified (signal intensity ratio, SIR; vessel sharpness). Wilcoxon, McNemar, and paired t tests were used.
Subjective image quality was significantly higher using XD-GRASP compared to 1D-MCA (median 4.5, interquartile range 4.5-5.0 versus 4.0 [2.25-4.75]; p < 0.001), as well as signal homogeneity (3.0 [3.0-3.0] versus 2.0 [2.0-3.0]; p = 0.003), and image sharpness (3.0 [2.0-3.0] vs 2.0 [1.25-3.0]; p < 0.001). SIR with the 1D-MCA and XD-GRASP was 6.1 ± 3.9 versus 7.4 ± 2.5, respectively (p < 0.001); while signal homogeneity was 274.2 ± 265.0 versus 199.8 ± 67.2 (p = 0.129). XD-GRASP provided a higher vessel sharpness (45.3 ± 10.7 versus 40.6 ± 101, p = 0.025).
XD-GRASP-based motion-resolved reconstruction of free-breathing 3D whole-heart MRA datasets provides improved image contrast, sharpness, and signal homogeneity and seems to be a promising technique that overcomes some of the limitations of motion correction or respiratory navigator gating.
全心脏磁共振血管造影（MRA）需要复杂的方法来处理呼吸运动。我们的目的是评估基于压缩感知的呼吸运动分辨三维（3D）全心脏MRA与已知胸主动脉扩张患者的自导航运动校正全心脏MRA相比的图像质量。
25名患者前瞻性纳入这项伦理批准的研究。使用原型3D径向稳态自由进动自由呼吸序列采集全心脏1.5-T MRA。相同的数据用一维运动校正算法（1D-MCA）和超维黄金角径向稀疏并行重建（XD-GRASP）进行重建。对主观图像质量进行评分，并对客观图像质量进行量化（信号强度比，SIR；血管清晰度）。使用Wilcoxon、McNemar和配对t检验。
与1D-MCA相比，使用XD-GRASP时主观图像质量显著更高（中位数4.5，四分位间距4.5-5.0对4.0[2.25-4.75]；p<0.001），信号均匀性（3.0[3.0-3.0]对2.0[2.0-3.0]；p=0.003）和图像清晰度（3.0[2.0-3.0]对2.0[1.25-3.0]；p<0.001）。1D-MCA和XD-GRASP的SIR分别为6.1±3.9和7.4±2.5（p<0.001）；而信号均匀性为274.2±265.0和199.8±67.2（p=0.129）。XD-GRASP提供了更高的血管清晰度（45.3±10.7对40.6±101，p=0.025）。
基于XD-GRASP的自由呼吸3D全心脏MRA数据集的运动分辨重建提供了改善的图像对比度、清晰度和信号均匀性，似乎是一种有前途的技术，克服了运动校正或呼吸导航门控的一些局限性。
