School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.
Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China.
Magn Reson Med. 2019 Oct;82(4):1331-1342. doi: 10.1002/mrm.27811. Epub 2019 May 17.
To develop a free-running (free-breathing, retrospective cardiac gating) 3D myocardial T mapping with isotropic spatial resolution.
The free-running sequence is inversion recovery (IR)-prepared followed by continuous 3D golden angle radial data acquisition. 1D respiratory motion signal is extracted from the k-space center of all spokes and used to bin the k-space data into different respiratory states, enabling estimation and correction of 3D translational respiratory motion, whereas cardiac motion is recorded using electrocardiography and synchronized with data acquisition. 3D translational respiratory motion compensated T maps at diastole and systole were generated with 1.5 mm isotropic spatial resolution with low-rank inversion and high-dimensionality patch-based undersampled reconstruction. The technique was validated against conventional methods in phantom and 9 healthy subjects.
Phantom results demonstrated good agreement (R = 0.99) of T estimation with reference method. Homogeneous systolic and diastolic 3D T maps were reconstructed from the proposed technique. Diastolic septal T estimated with the proposed method (1140 ± 36 ms) was comparable to the saturation recovery single-shot acquisition (SASHA) sequence (1153 ± 49 ms), but was higher than the modified Look-Locker inversion recovery (MOLLI) sequence (1037 ± 33 ms). Precision of the proposed method (42 ± 8 ms) was comparable to MOLLI (41 ± 7 ms) and improved with respect to SASHA (87 ± 19 ms).
The proposed free-running whole heart T mapping method allows for reconstruction of isotropic resolution 3D T maps at different cardiac phases, serving as a promising tool for whole heart myocardial tissue characterization.
开发一种自由运行（自由呼吸、回顾性心脏门控）的各向同性空间分辨率 3D 心肌 T 映射。
自由运行序列是反转恢复（IR）准备，然后进行连续的 3D 黄金角径向数据采集。从所有辐条的 k 空间中心提取 1D 呼吸运动信号，并将 k 空间数据分为不同的呼吸状态，从而能够估计和校正 3D 平移呼吸运动，而心脏运动则使用心电图记录并与数据采集同步。使用低秩反演和高维基于补丁的欠采样重建技术，以 1.5 毫米各向同性空间分辨率生成舒张期和收缩期的 3D 平移呼吸运动补偿 T 映射。该技术在体模和 9 名健康受试者中与传统方法进行了验证。
体模结果表明 T 估计与参考方法具有良好的一致性（R = 0.99）。从提出的技术中重建了均匀的收缩期和舒张期 3D T 映射。用提出的方法估计的舒张期室间隔 T（1140 ± 36 ms）与饱和恢复单次采集（SASHA）序列（1153 ± 49 ms）相当，但高于改良 Look-Locker 反转恢复（MOLLI）序列（1037 ± 33 ms）。该方法的精度（42 ± 8 ms）与 MOLLI（41 ± 7 ms）相当，并且优于 SASHA（87 ± 19 ms）。
提出的自由运行全心 T 映射方法允许在不同的心脏相位重建各向同性分辨率 3D T 映射，是一种有前途的全心心肌组织特征描述工具。
