Iterative reconstruction for quantitative computed tomography analysis of emphysema: consistent results using different tube currents.
Iterative reconstruction for quantitative computed tomography analysis of emphysema: consistent results using different tube currents.
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DOI：
10.2147/copd.s74810
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发表时间：
2015
影响因子：
2.8
通讯作者：
Murayama S
中科院分区：
文献类型：
--
作者：
Yamashiro T;Miyara T;Honda O;Tomiyama N;Ohno Y;Noma S;Murayama S
评估迭代重建用于肺气肿定量计算机断层扫描（CT）分析的优势。22例肺气肿患者使用三种不同管电流（240、120和60 mA）的相同扫描仪进行胸部CT成像。使用三维处理自适应迭代剂量减少（AIDR 3D）和传统的滤波反投影模式将扫描数据转换为CT图像。因此，每例患者生成了6次使用和不使用AIDR 3D的扫描。所有其他扫描和重建设置都是固定的。使用商用工作站自动测量低衰减面积百分比（LAA%; <-950 Hounsfield单位）和肺密度第15百分位数。通过Wilcoxon符号秩检验比较使用和不使用AIDR 3D扫描的LAA%和第15百分位数结果。通过斯皮尔曼等级相关分析评价这些扫描中体重和测量误差之间的关联。总体而言，在每个管电流下，无AIDR 3D的扫描系列的LAA%高于有AIDR 3D的扫描系列，第15百分位数值低于有AIDR 3D的扫描系列（P<0.0001）。对于无AIDR 3D的扫描系列，较低的管电流导致较高的LAA%值和较低的第15次扫描。当不使用AIDR 3D时，每对扫描之间的肺气肿程度有显著差异（LAA%，P<0.0001;第15百分位数，P<0.01），但当使用AIDR 3D时，每对扫描之间无显著差异。在不使用AIDR 3D的扫描中，不同管电流设置之间的测量误差与患者体重显著相关（P<0.05），而使用AIDR 3D时，扫描之间的这些误差与体重无显著或极轻微相关。当使用AIDR 3D将CT扫描转换为CT图像时，肺气肿的程度在不同的管电流中比使用传统的滤波反投影方法更一致。
To assess the advantages of iterative reconstruction for quantitative computed tomography (CT) analysis of pulmonary emphysema. Twenty-two patients with pulmonary emphysema underwent chest CT imaging using identical scanners with three different tube currents: 240, 120, and 60 mA. Scan data were converted to CT images using Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D) and a conventional filtered-back projection mode. Thus, six scans with and without AIDR3D were generated per patient. All other scanning and reconstruction settings were fixed. The percent low attenuation area (LAA%; < −950 Hounsfield units) and the lung density 15th percentile were automatically measured using a commercial workstation. Comparisons of LAA% and 15th percentile results between scans with and without using AIDR3D were made by Wilcoxon signed-rank tests. Associations between body weight and measurement errors among these scans were evaluated by Spearman rank correlation analysis. Overall, scan series without AIDR3D had higher LAA% and lower 15th percentile values than those with AIDR3D at each tube current (P<0.0001). For scan series without AIDR3D, lower tube currents resulted in higher LAA% values and lower 15th percentiles. The extent of emphysema was significantly different between each pair among scans when not using AIDR3D (LAA%, P<0.0001; 15th percentile, P<0.01), but was not significantly different between each pair among scans when using AIDR3D. On scans without using AIDR3D, measurement errors between different tube current settings were significantly correlated with patients’ body weights (P<0.05), whereas these errors between scans when using AIDR3D were insignificantly or minimally correlated with body weight. The extent of emphysema was more consistent across different tube currents when CT scans were converted to CT images using AIDR3D than using a conventional filtered-back projection method.