4-Dimensional computed tomography-based ventilation and compliance images for quantification of radiation-induced changes in pulmonary function.
4-Dimensional computed tomography-based ventilation and compliance images for quantification of radiation-induced changes in pulmonary function.
复制标题
基于 4 维计算机断层扫描的通气和顺应性图像，用于量化辐射引起的肺功能变化。
DOI：
10.1111/1754-9485.12881
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发表时间：
2019
影响因子：
1.6
通讯作者：
Zhong,Hualiang
中科院分区：
文献类型：
--
作者：
Sharifi,Hoda;Brown,Stephen;McDonald,GaryC;Chetty,IndrinJ;Zhong,Hualiang
基于四维计算机断层扫描（4DCT）的通气成像是一种很有前途的肺功能评价技术，但肺弹性和力学通常不是通气图像分析的一部分。在这项研究中，我们展示了一种基于4DCT的成像技术，可用于计算放射治疗（RT）后局部肺顺应性的变化。其中4例患者在RT前、RT后3个月和9个月获得了4DCT图像。根据从吸气末到呼气末呼吸阶段进行的4DCT的可变形图像配准（RDT）计算通气量和顺应性。区域顺应性定义为每个体素中体积变化和相关应力的比率，代表肺弹性，并使用基于FEM的框架计算。计算所有RT前和RT后4DCT的通气量、顺应性和CT密度，并计算评估指标。结果3个月后平均CT密度变化为13.6 ± 11.4HU，9个月后为26.9 ± 15.8HU。3个月时通气减少，但在剂量≥ 35戈伊的区域（约占肺体积的10%），9个月时通气改善;两个时间点的顺应性均降低。放射剂量≥ 35戈伊时，肺密度和肺通气量变化较大，高于文献报道的24戈伊。结合通气和CT密度顺应性可能有助于理解辐射诱导的肺损伤，从而有助于为肺癌患者制定更好的治疗方案。
Introduction4‐Dimensional computed tomography (4DCT)‐based ventilation imaging is a promising technique for evaluating pulmonary function, but lung elasticity and mechanics are usually not part of the ventilation image analysis. In this study we demonstrate a 4DCT‐based imaging technique that can be used to calculate regional lung compliance changes after radiotherapy (RT).MethodsSix lung cancer patients were included in this study. Four of the patients had 4DCT images acquired pre‐RT, 3 and 9 months post‐RT. Ventilation and compliance were calculated from the deformable image registration (DIR) of 4DCTs, performed from the end‐inhale to the end‐exhale breathing phase. Regional compliance was defined as the ratio of volumetric variation and associated stress in each voxel, representing lung elasticity and computed using a FEM‐based framework. Ventilation, compliance and CT density were calculated for all pre‐RT and post‐RT 4DCTs and evaluation metrics were computed.ResultsAverage CT density changes were 13.6 ± 11.4HU after 3 months and 26.9 ± 15.8HU after 9 months. Ventilation was reduced at 3 months, but improved at 9 months in regions with dose ≥ 35 Gy, encompassing about 10% of the lung volume; compliance was reduced at both time‐points. Radiation dose ≥ 35 Gy caused major change in lung density and ventilation, which was higher than that previously reported in the literature (i.e. 24 Gy).ConclusionLung tissue response is diverse with respect to CT density, ventilation and compliance. Combination of ventilation and compliance with CT density could be beneficial for understanding radiation‐induced lung damage and consequently could help develop improved treatment protocols for lung cancer patients.