多层螺旋CT灌注成像对肺栓塞-再灌注损伤的实验研究

目的应用CT灌注成像技术量化评价肺栓塞再灌注损伤,探讨肺栓塞再灌注损伤形成机制。方法选择14只健康杂种犬为实验对象。利用SwanGanz导管模拟肺膈叶动脉栓塞再灌注。栓塞前、栓塞24h和再通4h要分别进行肺动脉压测定、CT灌注成像和血清超氧化物歧化酶(SOD)的测定。结果再灌注肺损伤主要表现为急性渗透性肺水肿。再灌注损伤肺的BF(325.69±134.00)ml·min-1·100g-1)]和MTT(1.98±0.44)s]与栓塞前正常基线值(409.58±88.42)ml·min-1·100g-1)和(1.87±0.48)s]的差异具有统计学意义(P<0.01和P<0.05)。再灌注4h的肺动脉压(25.79±6.25)mmHg]和超氧化物歧化酶的平均值(388.79±25.07)U/ml]与栓塞前正常基线值(22.31±3.77)mmHg和(404.38±23.81)U/ml]相比均具有统计学差异(P<0.05和P<0.05)。再灌注损伤侧肺的湿/干重比率(6.29±1.23)显著大于对侧肺(4.54±1.19),其差异也具有统计学意义(P<0.01),说明再灌注水肿增加了肺组织的含水量。结论CT灌注成像有效反映肺栓塞再灌注损伤的血流动力学改变。氧自由基对肺栓塞再灌注损伤的形成起重要作用。

Experimental study of multi-slice spiral CT perfusion imaging for pulmonary embolism-reperfusion injury

Objective To assess pulmonary embolism-reperfusion injury in quantitative multi-slice CT perfusion imaging and to explore the mechanisms of pulmonary embolism-reperfusion injury. Methods Experiments were made on 14 healthy canines. With the use of a Swan-Ganz catheter, pulmonary embolism-reperfusion maneuvers were done at diaphragmatic lobe arteries. Pulmonary artery pressure (PAP), CT perfusion imaging and superoxide dismutase (SOD) were undertaken at normal condition, at 24 h PE and at 4 h reperfusion. Results Reperfusion pulmonary injury was generally characterized by acute permeability edema. The mean of BF and MTT of the injured lung was (325.69±134.00) ml·min^-1·100 g^-1 and (1.98±0.44) s, which was significantly different (P<0.01 and P<0.05) from normal base-line level . The mean of PAP and SOD of 4 h reperfusion injury was (25.79±6.25) mmHg and (388.79±25.07) U/ml, which was significantly different (P<0.05 and P<0.05) from normal base-line level . The mean wet/dry weight ratio of the injured lung of (6.29±1.23) was significantly greater(P<0.01) than the mean value of (4.54±1.19) of the contralateral lung, suggesting that the increase in the lung water was due to reperfusion edema. Conclusion Multi-slice CT perfusion imaging may play an increasing role to delineate the depiction of pulmonary hemodynamics in pulmonary embolism-reperfusion injury. O₂ free radicals is a key factor in the pulmonary embolism-reperfusion injury.