Distribution of pulmonary ventilation using Xe-enhanced computed tomography in prone and supine dogs
Distribution of pulmonary ventilation using Xe-enhanced computed tomography in prone and supine dogs
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DOI：
10.1152/jappl.2001.90.2.421
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发表时间：
2001-02-01
影响因子：
3.3
通讯作者：
Simon, BA
中科院分区：
文献类型：
--
作者：
Marcucci, C;Nyhan, D;Simon, BA
Xe增强计算机断层扫描(CT；Xe-CT)是一种无创性测量完整受试者局部肺通气量的方法，由系列CT扫描中测量的放射性气体Xe的洗入率和洗脱率确定。我们使用Xe-CT通气法，结合其他定量CT测量，研究了健康、麻醉、机械通气犬在俯卧位和仰卧位时局部肺通气量和空气含量的分布。测量了5只杂种犬在俯卧位和仰卧位四个肺轴位的区域通气量和空气含量的垂直梯度。仰卧位的通气量随位置的变化而增加，平均斜率为7.3%/cm肺高度，而俯卧位的通气量无明显变化。这些结果与其他已发表的研究在数量上是一致的。此外，还研究了6种不同的动物(仰卧3只，俯卧3只)，以检查通气量和空气含量的纵向分布。与仰卧位相比，俯卧位的肺充气更均匀，仰卧位的肺底部扩张得不如顶端。通气性指数是衡量局部通气量相对于全肺通气量的一个指标，在仰卧位动物中，从顶端到底部急剧增加，而俯卧位时则更为均匀。我们认为，Xe-CT方法提供了一种合理、定量的区域通气量测量方法，有望成为无创检测区域肺功能的有价值的工具。
Xe-enhanced computed tomography (CT; Xe-CT) is a method for the noninvasive measurement of regional pulmonary ventilation in intact subjects, determined from the washin and washout rates of the radiodense, nonradioactive gas Xe, as measured in serial CT scans. We used the Xe-CT ventilation method, along with other quantitative CT measurements, to investigate the distribution of regional lung ventilation and air content in healthy, anesthetized, mechanically ventilated dogs in the prone and supine postures. Vertical gradients in regional ventilation and air content were measured in five mongrel dogs in both prone and supine postures at four axial lung locations. In the supine position, ventilation increased with dependent location, with a mean slope of 7.3%/cm lung height, whereas no ventilation gradients were found at any location in the prone position. These results agree quantitatively with other published studies. In addition, six different animals were studied (3 supine, 3 prone) to examine the longitudinal distribution of ventilation and air content. The prone lungs were more uniformly inflated compared with the supine, which were less well expanded at the base than apex. Ventilation index, a measure of regional ventilation relative to whole lung ventilation, increased steeply from apex to base in the supine animals, whereas it was again more uniform in the prone condition. We conclude that the Xe-CT method provides a reasonable, quantitative measurement of regional ventilation and promises to be a valuable tool for the noninvasive determination of regional lung function.