Translational Medicine, Hospital for Sick Children, Toronto, Canada.
Physiology, University of Toronto, Toronto, Canada.
Magn Reson Med. 2020 Feb;83(2):535-548. doi: 10.1002/mrm.27945. Epub 2019 Aug 29.
To test and implement a motion-robust and respiratory-resolved 3D Radial Flow framework that addresses the need for rapid, high resolution imaging in neonatal patients with congenital heart disease.
A 4-point velocity encoding and 3D radial trajectory with double-golden angle ordering was combined with bulk motion correction (from projection center of mass) and respiration phase detection (from principal component analysis of heartbeat-averaged data) to create motion-robust 3D velocity cardiac time-averaged data. This framework was tested in a whole-chest digital phantom with simulated bulk and realistic physiological motion. In vivo imaging was performed in 20 congenital heart disease infants under feed-and-sleep with submillimeter isotropic resolution in ~3 min. Flows were validated against clinical 2D PCMRI and whole-heart visualizations of blood flow were performed.
The proposed framework resolved all simulated digital phantom motion states (mean ± standard error: rotation - azimuthal = 0.29 ± 0.02°; translation - T = 1.29 ± 0.12 mm, T = -0.27 ± 0.13 mm; rotation+translation - polar = 0.49 ± 0.16°, T = -2.47 ± 0.51 mm, T = 5.78 ± 1.33 mm). Measured timing errors of peak expiration across all signal-to-noise ratio values were 22% of the true respiratory period (range = [404-489 ± 298-334] ms). For in vivo imaging, motion correction improved 3D Radial Flow measurements (no correction: R = 0.62, root mean square error = 0.80 L/min/m , Bland-Altman bias [limits of agreement] = -0.21 [-1.40, 0.94] L/min/m ; motion corrected, expiration: R = 0.90, root mean square error = 0.46 L/min/m , bias [limits of agreement] = 0.06 [-0.49, 0.62] L/min/m ). Respiratory-resolved 3D velocity visualizations were achieved in various neonatal pathologies pre- and postsurgical correction.
3D cardiac flow may be visualized and accurately quantified in neonatal subjects using the proposed framework. This technique may enable more comprehensive hemodynamic studies in small infants.
测试并实现一种运动鲁棒和呼吸分辨的 3D 径向流框架，以满足对患有先天性心脏病的新生儿进行快速、高分辨率成像的需求。
将四点速度编码和具有双黄金角排序的 3D 径向轨迹与整体运动校正（从投影质心）和呼吸相位检测（从心跳平均数据的主成分分析）相结合，创建运动鲁棒的 3D 速度心脏时间平均数据。该框架在具有模拟整体运动和真实生理运动的全胸数字体模中进行了测试。在 20 名接受喂养和睡眠的先天性心脏病婴儿中进行了体内成像，具有亚毫米各向同性分辨率，大约需要 3 分钟。对流量进行了与临床 2D PCMRI 和全心脏血流可视化的验证。
所提出的框架解决了所有模拟数字体模运动状态（平均值±标准误差：旋转-方位角 = 0.29 ± 0.02°；平移-T = 1.29 ± 0.12 mm，T = -0.27 ± 0.13 mm；旋转+平移-极角 = 0.49 ± 0.16°，T = -2.47 ± 0.51 mm，T = 5.78 ± 1.33 mm）。在所有信噪比值下，呼气末峰值的测量时间误差均为真实呼吸周期的 22%（范围为[404-489 ± 298-334] ms）。对于体内成像，运动校正改善了 3D 径向流测量（无校正：R = 0.62，均方根误差 = 0.80 L/min/m，Bland-Altman 偏差[协议范围] = -0.21 [-1.40，0.94] L/min/m；运动校正，呼气末：R = 0.90，均方根误差 = 0.46 L/min/m，偏差[协议范围] = 0.06 [-0.49，0.62] L/min/m）。在各种新生儿先心病的术前和术后校正中，均实现了呼吸分辨的 3D 速度可视化。
使用所提出的框架可以在新生儿中可视化和准确量化 3D 心脏流量。该技术可以使小型婴儿的血流动力学研究更加全面。
