Respiratory motion-resolved, self-gated 4D-MRI using rotating cartesian k-space (ROCK).
Respiratory motion-resolved, self-gated 4D-MRI using rotating cartesian k-space (ROCK).
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DOI：
10.1002/mp.12139
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发表时间：
2017-04
期刊：
影响因子：
3.8
通讯作者：
Hu P
中科院分区：
文献类型：
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作者：
Han F;Zhou Z;Cao M;Yang Y;Sheng K;Hu P
提出并验证一种呼吸运动分辨、自门(SG)4D-MRI技术，用于评估患者特定的腹部器官呼吸运动，用于放射治疗计划。所提出的4D-MRI技术是基于平衡稳态自由进动(BSSFP)技术和3Dk空间编码。设计了一种新的旋转笛卡尔K空间(ROCK)重排序方法，该方法采用重复采样的k空间中心线作为SG运动代理，并允许根据代理的幅度将k空间数据回溯到不同的呼吸位置。随后，使用具有空间和时间正则化的联合并行成像和压缩传感方法重建多个呼吸分辨率的3Dk空间数据。使用定制的动态运动体模对所提出的4D-MRI技术进行了验证，并在6名健康志愿者身上进行了测试，其中基于4D-MRI图像的定量横隔膜和肾脏运动测量与基于2D-Cine图像的测量结果进行了比较。5分钟的4D-MRI扫描提供1.2×1.2×1.6 mm~3和8个呼吸位置的高质量体积图像，具有良好的软组织对比度。在三角形运动波形的体模实验中，基于4D-MRI的运动幅度测量结果比地面真实数据小11.89%，而由于数据绑定效应，−预计会有12.5%的差异。在健康志愿者中，4D-MRI与2D-Cine的测量结果相差6.2±4.5%，左右肾分别为8.2±4.9%和8.9±5.1%。提出的4D-MRI技术可以提供高分辨率、高质量、呼吸运动分辨率的4D图像，具有良好的软组织对比度，并且避免了在2D-Cine基础上的4D-CT和4D-MRI中常见的缝合伪影。它可以用于可视化和量化腹部器官的运动，用于基于MRI的放射治疗计划。
To propose and validate a respiratory motion resolved, self-gated (SG) 4D-MRI technique to assess patient-specific breathing motion of abdominal organs for radiation treatment planning. The proposed 4D-MRI technique was based on the balanced steady-state free-precession (bSSFP) technique and 3D k-space encoding. A novel ROtating Cartesian K-space (ROCK) reordering method was designed that incorporates repeatedly sampled k-space centerline as the SG motion surrogate and allows for retrospective k-space data binning into different respiratory positions based on the amplitude of the surrogate. The multiple respiratory-resolved 3D k-space data were subsequently reconstructed using a joint parallel imaging and compressed sensing method with spatial and temporal regularization. The proposed 4D-MRI technique was validated using a custom-made dynamic motion phantom and was tested in 6 healthy volunteers, in whom quantitative diaphragm and kidney motion measurements based on 4D-MRI images were compared with those based on 2D-CINE images. The 5-minute 4D-MRI scan offers high-quality volumetric images in 1.2×1.2×1.6mm3 and 8 respiratory positions, with good soft-tissue contrast. In phantom experiments with triangular motion waveform, the motion amplitude measurements based on 4D-MRI were 11.89% smaller than the ground truth, whereas a −12.5% difference was expected due to data binning effects. In healthy volunteers, the difference between the measurements based on 4D-MRI and the ones based on 2D-CINE were 6.2±4.5% for the diaphragm, 8.2±4.9% and 8.9±5.1% for the right and left kidney. The proposed 4D-MRI technique could provide high resolution, high quality, respiratory motion resolved 4D images with good soft-tissue contrast and are free of the “stitching” artifacts usually seen on 4D-CT and 4D-MRI based on resorting 2D-CINE. It could be used to visualize and quantify abdominal organ motion for MRI-based radiation treatment planning.