PDF(Pubmed)
Abstract：
Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death. Recent studies have underlined the importance of non-contrast-enhanced chest CT scans not only for emphysema progression quantification, but for correlation with clinical outcomes as well. As about 40 percent of the 300 million CT scans per year are contrast-enhanced, no proper emphysema quantification is available in a one-stop-shop approach for patients with known or newly diagnosed COPD. Since the introduction of spectral imaging (e.g., dual-energy CT scanners), it has been possible to create virtual non-contrast-enhanced images (VNC) from contrast-enhanced images, making it theoretically possible to offer proper COPD imaging despite contrast enhancing. This study is aimed towards investigating whether these VNC images are comparable to true non-contrast-enhanced images (TNC), thereby reducing the radiation exposure of patients and usage of resources in hospitals. In total, 100 COPD patients with two scans, one with (VNC) and one without contrast media (TNC), within 8 weeks or less obtained by a spectral CT using dual-layer technology, were included in this retrospective study. TNC and VNC were compared according to their voxel-density histograms. While the comparison showed significant differences in the low attenuated volumes (LAVs) of TNC and VNC regarding the emphysema threshold of -950 Houndsfield Units (HU), the 15th and 10th percentiles of the LAVs used as a proxy for pre-emphysema were comparable. Upon further investigation, the threshold-based LAVs (-950 HU) of TNC and VNC were comparable in patients with a water equivalent diameter (DW) below 270 mm. The study concludes that VNC imaging may be a viable option for assessing emphysema progression in COPD patients, particularly those with a normal body mass index (BMI). Further, pre-emphysema was generally comparable between TNC and VNC. This approach could potentially reduce radiation exposure and hospital resources by making additional TNC scans obsolete.
摘要：
慢性阻塞性肺疾病（COPD）是导致死亡的主要原因之一。最近的研究强调了非对比增强胸部CT扫描不仅对肺气肿进展量化的重要性。但也与临床结果相关。由于每年3亿次CT扫描中约有40％是对比增强的，对于已知或新诊断的COPD患者,在一站式方法中没有正确的肺气肿量化.由于引入了光谱成像(例如，双能量CT扫描仪)，可以从对比度增强的图像创建虚拟非对比度增强的图像（VNC），尽管对比度增强，但理论上仍有可能提供适当的COPD成像。这项研究旨在调查这些VNC图像是否与真正的非对比增强图像（TNC）相当。从而减少患者的辐射暴露和医院资源的使用。总的来说,100名COPD患者进行了两次扫描，一个有（VNC），一个没有造影剂（TNC），在8周或更短的时间内通过使用双层技术的能谱CT获得，纳入本回顾性研究。根据它们的体素密度直方图比较TNC和VNC。虽然比较显示TNC和VNC的低衰减体积（LAV）关于-950Houndsfield单位（HU）的肺气肿阈值的显着差异，用作肺气肿前期替代指标的第15百分位数和第10百分位数具有可比性.经进一步调查,在水当量直径(DW)低于270mm的患者中,TNC和VNC的基于阈值的LAV(-950HU)具有可比性.该研究得出结论，VNC成像可能是评估COPD患者肺气肿进展的可行选择。特别是那些体重指数（BMI）正常的人。Further,肺气肿前期在TNC和VNC之间具有可比性。这种方法可以通过淘汰额外的TNC扫描来潜在地减少辐射暴露和医院资源。
