School of Biomedical Engineering, ShanghaiTech University, Shanghai, People's Republic of China.
United Imaging Healthcare, Shanghai, People's Republic of China.
Magn Reson Med. 2022 Dec;88(6):2520-2531. doi: 10.1002/mrm.29417. Epub 2022 Aug 31.
To develop a fast free-breathing whole-heart high-resolution myocardial T mapping technique with robust spin-lock preparation that can be performed at 3 Tesla.
An adiabatically excited continuous-wave spin-lock module, insensitive to field inhomogeneities, was implemented with an electrocardiogram-triggered low-flip angle spoiled gradient echo sequence with variable-density 3D Cartesian undersampling at a 3 Tesla whole-body scanner. A saturation pulse was performed at the beginning of each cardiac cycle to null the magnetization before T preparation. Multiple T -weighted images were acquired with T preparations with different spin-lock times in an interleaved fashion. Respiratory self-gating approach was adopted along with localized autofocus to enable 3D translational motion correction of the data acquired in each heartbeat. After motion correction, multi-contrast locally low-rank reconstruction was performed to reduce undersampling artifacts. The accuracy and feasibility of the 3D T mapping technique was investigated in phantoms and in vivo in 10 healthy subjects compared with the 2D T mapping.
The 3D T mapping technique provided similar phantom T measurements in the range of 25-120 ms to the 2D T mapping reference over a wide range of simulated heart rates. With the robust adiabatically excited continuous-wave spin-lock preparation, good quality 2D and 3D in vivo T -weighted images and T maps were obtained. Myocardial T values with the 3D T mapping were slightly longer than 2D breath-hold measurements (septal T : 52.7 ± 1.4 ms vs. 50.2 ± 1.8 ms, P < 0.01).
A fast 3D free-breathing whole-heart T mapping technique was proposed for T quantification at 3 T with isotropic spatial resolution (2 mm ) and short scan time of ∼4.5 min.
开发一种快速的自由呼吸全心高分辨率心肌 T 映射技术，该技术具有稳健的自旋锁定准备，可在 3T 下进行。
在 3T 全身扫描仪上，实现了一种对磁场不均匀性不敏感的绝热连续波自旋锁定模块，该模块与心电图触发的低翻转角扰相梯度回波序列相结合，采用可变密度 3D 笛卡尔欠采样。在每个心动周期开始时，使用饱和脉冲对磁化进行预饱和，以在 T 准备之前将其置零。采用呼吸自门控方法结合局部自动聚焦，对每个心跳采集的数据进行 3D 平移运动校正，以实现不同自旋锁定时间的 T -加权图像的交替采集。校正后，采用多对比度局部低秩重建来减少欠采样伪影。在体模和 10 名健康志愿者中，与 2D T 映射相比，研究了该 3D T 映射技术的准确性和可行性。
在模拟的广泛心率范围内，3D T 映射技术在 25-120ms 的范围内提供了与 2D T 映射参考相似的体模 T 测量值。采用稳健的绝热连续波自旋锁定准备，可获得高质量的 2D 和 3D 体内 T -加权图像和 T 图。3D T 映射的心肌 T 值略长于 2D 屏气测量值（室间隔 T ：52.7±1.4ms 比 50.2±1.8ms，P<0.01）。
提出了一种快速的 3D 自由呼吸全心 T 映射技术，可在 3T 下进行 T 定量测量，具有各向同性空间分辨率（2mm）和短扫描时间（约 4.5min）。
