Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
J Thorac Imaging. 2010 Nov;25(4):311-9. doi: 10.1097/RTI.0b013e3181cbc28b.
First, to test the hypothesis that air trapping in diseased patients follows a gravitational gradient and is more extensive in dependent than in nondependent lung regions. Second, to test the hypothesis that the dependent lung regions on combined supine and prone expiratory computed tomography (CT) examinations will show more air trapping than would a supine expiratory CT examination alone.
For this ethics committee-approved study, supine and prone multidetector-row CT (4×1 mm collimation, 0.5 s rotation time, 140 kVp, and effective 80 mAs) was performed at full end-expiration on 47 lung transplant recipients (mean age 41±12 y; 18 without bronchiolitis, 18 with potential bronchiolitis, and 11 with bronchiolitis). The extent of air trapping was visually quantified in the supine and prone positions, and in dependent and nondependent lung regions. Individual air trapping scores from these regions were thus available and could be combined for later analysis. Differences in the extent of air trapping between the positions and regions were tested with a Wilcoxon signed-rank test.
Air trapping was significantly more extensive in the combined dependent lung regions than in the combined nondependent lung regions (15.00% vs. 5.77%; P<0.001). Air trapping was also significantly more extensive in the combined dependent regions than in the supine body position (15.00% vs. 7.50%; P<0.001). No statistically significant difference in the extent of air trapping was found between the supine and the prone positions (7.50% vs. 12.14%; P=0.735).
In patients with suspected or overt small airways disease, air trapping follows a gravitational gradient. A change from the supine to the prone position can make air trapping visible in formerly nondependent lung regions. The combined readings from supine and prone CT examinations in dependent lung regions show more air trapping than a standard supine CT examination alone.
首先，验证在患病患者中空气滞留遵循重力梯度，且在非依赖区比在依赖区更为广泛。其次，验证在仰卧位和俯卧位联合呼气 CT（CT）检查中，依赖区比单独仰卧位呼气 CT 检查显示更多的空气滞留的假设。
这项经伦理委员会批准的研究对 47 例肺移植受者（平均年龄 41±12 岁；无细支气管炎 18 例，潜在细支气管炎 18 例，细支气管炎 11 例）在完全呼气末进行仰卧位和俯卧位多排 CT（4×1mm 准直，0.5s 旋转时间，140kVp，有效 80mAs）。在仰卧位和俯卧位以及依赖区和非依赖区对空气滞留的程度进行视觉定量。这些区域的个体空气滞留评分因此可用，并可用于进一步分析。使用 Wilcoxon 符号秩检验比较不同位置和区域的空气滞留程度。
在联合依赖区，空气滞留明显比联合非依赖区更广泛（15.00% vs. 5.77%；P<0.001）。在联合依赖区，空气滞留也明显比仰卧位更广泛（15.00% vs. 7.50%；P<0.001）。在仰卧位和俯卧位之间，空气滞留程度没有统计学上的显著差异（7.50% vs. 12.14%；P=0.735）。
在疑似或显性小气道疾病患者中，空气滞留遵循重力梯度。从仰卧位改为俯卧位可使以前非依赖区的空气滞留可见。依赖区仰卧位和俯卧位 CT 检查的综合读数显示出比单独仰卧位 CT 检查更多的空气滞留。
