Simon D S, Murray J F, Staub N C
J Appl Physiol Respir Environ Exerc Physiol. 1979 Dec;47(6):1228-33. doi: 10.1152/jappl.1979.47.6.1228.
We evaluated the attenuation of the 122 keV gamma ray of cobalt-57 across the thorax of anesthetized dogs as a method for following the time course of lung water changes in acute pulmonary edema induced by either increased microvascular permeability or increased microvascular hydrostatic pressure. The gamma rays traversed the thorax centered on the seventh rib laterally where the lung mass in the beam path was greatest. Calibration measurements in isolated lung lobes demonstrated the high sensitivity and inherent accuracy of the method over a wide range of lung water contents. In control dogs reproducibility averaged +/-3%. Increased permeability edema led to large rapid increases in the transthoracic gamma ray attenuation (TGA), while increased pressure caused an immediate, modest increase in TGA (vascular congestion) followed by a slow further increase over 2 h. There was a fairly good correlation between the increase in extravascular lung water and the change in TGA. The method is simple, safe, and noninvasive and appears to be useful for following the time course of lung water accumulation in generalized lung edema in anesthetized animals.
我们评估了钴 -57 的 122 千电子伏特伽马射线穿过麻醉犬胸部的衰减情况，以此作为一种追踪因微血管通透性增加或微血管静水压力增加所诱发的急性肺水肿中肺水变化时间进程的方法。伽马射线横向穿过以第七肋骨为中心的胸部，此处射线路径中的肺组织量最大。在离体肺叶上进行的校准测量表明，该方法在广泛的肺水含量范围内具有高灵敏度和内在准确性。在对照犬中，重现性平均为±3%。通透性增加所致的水肿导致经胸伽马射线衰减（TGA）迅速大幅增加，而压力增加则使 TGA 立即出现适度增加（血管充血），随后在 2 小时内缓慢进一步增加。血管外肺水的增加与 TGA 的变化之间存在相当良好的相关性。该方法简单、安全且无创，似乎可用于追踪麻醉动物全身性肺水肿中肺水积聚的时间进程。
