Technical Note: Correlation of respiratory motion between external patient surface and internal anatomical landmarks
Technical Note: Correlation of respiratory motion between external patient surface and internal anatomical landmarks
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DOI：
10.1118/1.3589131
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发表时间：
2011-06-01
期刊：
影响因子：
3.8
通讯作者：
Visvikis, Dimitris
中科院分区：
文献类型：
--
作者：
Fayad, Hadi;Pan, Tinsu;Visvikis, Dimitris
目的：用于医学成像和放射治疗中的运动同步的当前呼吸运动监测设备提供特定区域上的1D呼吸信号或基于很少的外部或内部标记的3D信息。另一方面，更新的技术可以提供真实的时间监测整个患者外表面的潜力。本研究的主要目的是评估这样一个外部患者表面和内部解剖标志motion.Methods：四维计算机断层扫描（4D CT）体积为10例患者之间的运动相关性。由两名专家在4D CT数据集中手动选择胸部区域的解剖标志。标志物包括正常结构以及肿瘤位置。此外，通过使用阈值算法分割所有4D CT体积的皮肤来创建表示整个外部患者表面的距离图，该距离图对应于由飞行时间（ToF）相机或类似设备采集的表面。最后，内部标志和外部表面运动之间的相关性进行了评估，为不同的区域（位置和大小）在整个病人的surfaces.Results：观察到显着的变化，在外部患者表面的不同部分的运动。对于所考虑的不同患者数据集，在腹部和胸部区域的中心区域始终测量到较大的运动幅度。观察到这些外表面区域的运动与内部标志（例如横膈膜和纵隔结构）以及肿瘤位置标志之间的相关系数最高（腹部和胸部区域分别为0.8 +/- 0.18和0.72 +/- 0.12）。较差的相关性被观察到，当一个考虑地标不显着影响呼吸运动，如顶点和sternum.Conclusions：有很大的差异，观察到的运动相关性，考虑到不同地区的利益放在一个病人的外表面和内部解剖标志。用于呼吸运动同步的当前设备的定位可以通过对相关和不良相关的外部区域上的运动进行平均来减少这种相关性。实时捕获完整的外部患者表面的运动以及选择与内部运动最佳相关的表面区域的潜力应当允许减少呼吸运动同步和后续运动建模过程中的这种可变性和相关误差。(C)2011年美国医学物理学家协会。[DOI 10.1118/1.3589131]
Purpose: Current respiratory motion monitoring devices used for motion synchronization in medical imaging and radiotherapy provide either 1D respiratory signal over a specific region or 3D information based on few external or internal markers. On the other hand, newer technology may offer the potential to monitor the entire patient external surface in real time. The main objective of this study was to assess the motion correlation between such an external patient surface and internal anatomical landmarks motion.Methods: Four dimensional computed tomography (4D CT) volumes for ten patients were used in this study. Anatomical landmarks were manually selected in the thoracic region across the 4D CT datasets by two experts. The landmarks included normal structures as well as the tumor location. In addition, a distance map representing the entire external patient surface, which corresponds to surfaces acquired by a time of flight (ToF) camera or similar devices, was created by segmenting the skin of all 4D CT volumes using a thresholding algorithm. Finally, the correlation between the internal landmarks and external surface motion was evaluated for different regions (placement and size) throughout a patient's surface.Results: Significant variability was observed in the motion of the different parts of the external patient surface. The larger motion magnitude was consistently measured in the central regions of the abdominal and the thoracic areas for the different patient datasets considered. The highest correlation coefficients were observed between the motion of these external surface areas and internal landmarks such as the diaphragm and mediastinum structures as well as the tumor location landmarks (0.8 +/- 0.18 and 0.72 +/- 0.12 for the abdominal and the thoracic regions, respectively). Worse correlation was observed when one considered landmarks not significantly influenced by respiratory motion such as the apex and the sternum.Conclusions: There were large differences in the motion correlation observed considering different regions of interest placed over a patients' external surface and internal anatomical landmarks. The positioning of current devices used for respiratory motion synchronization may reduce such correlation by averaging the motion over correlated and poorly correlated external regions. The potential of capturing in real-time the motion of the complete external patient surface as well as choosing the area of the surface that correlates best with the internal motion should allow reducing such variability and associated errors in both respiratory motion synchronization and subsequent motion modeling processes. (C) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3589131]