Aoki Kohei, Izumi Yotaro, Watanabe Wataru, Shimizu Yuji, Osada Hisato, Honda Norinari, Itoh Toshihide, Nakayama Mitsuo
Department of General Thoracic Surgery, Saitama Medical University, Medical Center, 1981 Kamoda, Kawagoeshi, Saitama, 350-8550, Japan.
Department of Radiology, Saitama Medical University, Medical Center, 1981 Kamoda, Kawagoeshi, Saitama, 350-8550, Japan.
J Cardiothorac Surg. 2018 May 18;13(1):43. doi: 10.1186/s13019-018-0737-2.
While many studies have evaluated the change in lung volume before and after lung resection and correlated this with pulmonary function test results, there is very little evidence on the changes in ventilation perfusion ratio (V/Q) before versus after lung resection. In the present pilot study, we evaluated if V/Q mapping can be constructed using dual energy CT images.
Thirty-one lung cancer patients planned for pulmonary resection were included in this study. To evaluate ventilation, Xenon-enhanced CT was performed. This was immediately followed by perfusion CT. The two images were registered manually as well as using dedicated softwares, and division between ventilation pixels and perfusion pixels were done to produce the V/Q map. Also, in order to characterize the distribution of the V/Q, the following numerical indices were calculated; mean, median, mode, standard deviation (SD), coefficient of variation (CV), skewness, kurtosis, and fractal dimension (FD). Pulmonary function tests and blood gas parameters were measured using standard institutional procedures.
In the whole group, VC, %VC, and FEV1 decreased significantly after resection. FEV1.0% was increased significantly after resection. No significant changes were seen in PaO2, PaCO2, and DLCO/VA before and after resection. The mean, median, mode, SD, skewness, kurtosis and FD of the V/Q did not change significantly before and after resection. A marginal but significant decrease in CV was seen before versus after resection.
Overall, it was considered that the V/Q maps could be adequately generated in this study. With further accumulation of data, V/Q map generated by dual energy CT may become one of the potentially useful tools for functional lung imaging.
This trial was registered in University Medical Information Network in Japan ( UMIN000010023 ) on 13Feb2013.
虽然许多研究评估了肺切除前后肺容积的变化，并将其与肺功能测试结果相关联，但关于肺切除前后通气灌注比（V/Q）变化的证据非常少。在本初步研究中，我们评估了是否可以使用双能CT图像构建V/Q图谱。
本研究纳入了31例计划进行肺切除的肺癌患者。为了评估通气情况，进行了氙增强CT检查。随后立即进行灌注CT检查。通过手动以及使用专用软件对这两幅图像进行配准，并对通气像素和灌注像素进行划分以生成V/Q图谱。此外，为了描述V/Q的分布特征，计算了以下数值指标：均值、中位数、众数、标准差（SD）、变异系数（CV）、偏度、峰度和分形维数（FD）。使用标准的机构程序测量肺功能测试和血气参数。
在整个研究组中，切除术后肺活量（VC）、%VC和第一秒用力呼气容积（FEV1）显著下降。切除术后FEV1.0%显著增加。切除前后动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）和一氧化碳弥散量/肺泡通气量（DLCO/VA）无显著变化。V/Q的均值、中位数、众数、SD、偏度、峰度和FD在切除前后无显著变化。切除前后CV有轻微但显著的下降。
总体而言，本研究认为可以充分生成V/Q图谱。随着数据的进一步积累，双能CT生成的V/Q图谱可能成为功能性肺成像的潜在有用工具之一。
本试验于2013年2月13日在日本大学医学信息网络注册（UMIN000010023）。
