School of Biomedical Engineering & State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, China.
Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Magn Reson Med. 2025 Feb;93(2):751-760. doi: 10.1002/mrm.30317. Epub 2024 Oct 7.
To develop a 3D free-breathing cardiac multi-parametric mapping framework that is robust to confounders of respiratory motion, fat, and B1+ inhomogeneities and validate it for joint myocardial T1 and T1ρ mapping at 3T.
An electrocardiogram-triggered sequence with dual-echo Dixon readout was developed, where nine cardiac cycles were repeatedly acquired with inversion recovery and T1ρ preparation pulses for T1 and T1ρ sensitization. A subject-specific respiratory motion model relating the 1D diaphragmatic navigator to the respiration-induced 3D translational motion of the heart was constructed followed by respiratory motion binning and intra-bin 3D translational and inter-bin non-rigid motion correction. Spin history B1+ inhomogeneities were corrected with optimized dual flip angle strategy. After water-fat separation, the water images were matched to the simulated dictionary for T1 and T1ρ quantification. Phantoms and 10 heathy subjects were imaged to validate the proposed technique.
The proposed technique achieved strong correlation (T1: R = 0.99; T1ρ: R = 0.98) with the reference measurements in phantoms. 3D cardiac T1 and T1ρ maps with spatial resolution of 2 × 2 × 4 mm were obtained with scan time of 5.4 ± 0.5 min, demonstrating comparable T1 (1236 ± 59 ms) and T1ρ (50.2 ± 2.4 ms) measurements to 2D separate breath-hold mapping techniques. The estimated B1+ maps showed spatial variations across the left ventricle with the septal and inferior regions being 10%-25% lower than the anterior and septal regions.
The proposed technique achieved efficient 3D joint myocardial T1 and T1ρ mapping at 3T with respiratory motion correction, spin history B1+ correction and water-fat separation.
开发一种 3D 自由呼吸心脏多参数映射框架，该框架能够抵抗呼吸运动、脂肪和 B1+不均匀性的干扰，并验证其在 3T 下进行联合心肌 T1 和 T1ρ 映射的性能。
开发了一种心电图触发的双回波 Dixon 读出序列，其中使用反转恢复和 T1ρ 预备脉冲重复采集九个心动周期以进行 T1 和 T1ρ 敏化。构建了一个与 1D 膈肌导航相关的、与心脏呼吸引起的 3D 平移运动相关的受试者特定呼吸运动模型，然后进行呼吸运动分箱和箱内 3D 平移运动校正和箱间非刚性运动校正。使用优化的双翻转角策略校正自旋历史 B1+不均匀性。在水脂分离后，将水图像与模拟字典进行匹配以进行 T1 和 T1ρ 定量。对体模和 10 名健康受试者进行成像以验证所提出的技术。
该技术在体模中与参考测量值具有很强的相关性（T1：R=0.99；T1ρ：R=0.98）。获得了具有 2×2×4mm 空间分辨率的 3D 心脏 T1 和 T1ρ 图，扫描时间为 5.4±0.5min，与 2D 单独屏气映射技术相比，T1（1236±59ms）和 T1ρ（50.2±2.4ms）测量值相当。估计的 B1+图显示出左心室的空间变化，其中间隔和下壁区域比前壁和间隔区域低 10%-25%。
该技术实现了高效的 3D 自由呼吸心脏多参数映射，具有呼吸运动校正、自旋历史 B1+校正和水脂分离功能，可在 3T 下进行联合心肌 T1 和 T1ρ 映射。
