Knight H, Petroll W M, Adams J M, Shaffer H A, Rochester D F
Department of Medicine, University of Virginia School of Medicine, Charlottesville 22908.
J Appl Physiol (1985). 1990 May;68(5):2200-7. doi: 10.1152/jappl.1990.68.5.2200.
We tested the hypothesis that dynamic shortening of the costal diaphragm can be accurately estimated from measurements of the radiographic width of the zone of apposition (WZapp) by studying seven supine anesthetized dogs. Both muscle fiber length, represented by the distance between implanted radiopaque markers, and WZapp were measured from digitized recordings of fluoroscopic images utilizing interactive computer software. The WZapp was highly correlated with the length of costal fibers during active respiration in all animals (mean R2 = 0.94). The accuracy in the prediction of fiber length and shortening during breathing is enhanced by inclusion of additional variables describing the displacement of the abdominal wall and the resting geometric orientation of the fibers. We conclude that dynamic fluoroscopic measurement of WZapp is a valuable technique for estimating dynamic diaphragm fiber length and shortening. Depending on the experimental circumstances, WZapp may be a more easily acquired indicator of diaphragm shortening than other variables that have been previously utilized. As such, it may provide a suitable approach to assess active shortening of the diaphragm in humans.
我们通过研究七只仰卧麻醉的狗，检验了以下假设：即通过测量贴附区的放射学宽度（WZapp），可以准确估计肋膈膜的动态缩短情况。利用交互式计算机软件，从荧光透视图像的数字化记录中测量了由植入的不透射线标记物之间的距离所代表的肌纤维长度以及WZapp。在所有动物的主动呼吸过程中，WZapp与肋纤维的长度高度相关（平均R2 = 0.94）。通过纳入描述腹壁位移和纤维静止几何方向的其他变量，可提高呼吸过程中纤维长度和缩短情况预测的准确性。我们得出结论，WZapp的动态荧光透视测量是估计膈膜动态纤维长度和缩短情况的一项有价值的技术。根据实验情况，WZapp可能是比先前使用的其他变量更容易获取的膈膜缩短指标。因此，它可能为评估人类膈膜的主动缩短提供一种合适的方法。
