Drobnitzky Matthias, Vom Endt Axel, Dewdney Andrew
Siemens Healthcare GmbH, Magnetic Resonance, Erlangen, Germany.
Phys Imaging Radiat Oncol. 2021 Feb 10;17:95-99. doi: 10.1016/j.phro.2021.01.012. eCollection 2021 Jan.
Magnetic resonance (MR)-only workflows require quality assurance due to potential dosimetric impacts of using geometry distorted MR images in radiotherapy planning. MR-visible silicone-based fiducials were arranged in regular 3D structures to cover extended imaging volumes. The scanner's patient marking workflow with a 2-axes movable laser bridge allowed to visually check geometric distortions of each MR reconstructed fiducial against its true position in 3D space. A measurement resolution and uncertainty of the order of 0.5 mm in sagittal and coronal, and 1 mm in transversal direction was found. The proposed workflow required 1 min of evaluation time per fiducial position, and a 9 min 3D MR volume acquisition.
仅使用磁共振（MR）的工作流程需要进行质量保证，因为在放射治疗计划中使用几何形状失真的MR图像可能会产生剂量学影响。基于MR可见的硅基基准标记被布置成规则的三维结构，以覆盖更大的成像体积。扫描仪带有双轴可移动激光桥的患者标记工作流程，允许针对每个MR重建基准标记在三维空间中的真实位置，直观地检查其几何失真情况。在矢状面和冠状面方向上发现测量分辨率和不确定度约为0.5毫米，在横断面方向上为1毫米。所提出的工作流程每个基准标记位置需要1分钟的评估时间，以及9分钟的三维MR体积采集时间。
