肺通气/血流灌注显像与螺旋CT肺动脉造影诊断肺栓塞的实验研究

Value of pulmonary perfusion/ventilation imaging and 64-slice computed tomographic pulmonary angiography for acute pulmonary embolism in rabbits

目的评价肺通气/血流灌注(pulmonary perfusion/ventilation,V/Q)显像与64层螺旋CT肺动脉造影(spiral computed tomographic pulmonary angiography,SCTPA)诊断肺栓塞的灵敏度和特异性。方法12只家兔按不同时间点分成4个实验组,每组3只,另设2只作为对照组。实验组经颈静脉插管注入海绵栓子制备急性肺栓塞模型,建模后分组行V/Q显像和SCTPA检查,随后处死实验动物行病理解剖,查找并记录肺动脉栓子位置及数目。对照组颈静脉插管注入生理盐水,于24 h和第3天处死。结果实验组家兔术中死亡1只,11只建模成功。家兔处死后共解剖动脉165支,发现栓子43个,栓塞肺动脉39支。V/Q显像共检出36处节段肺动脉栓塞,与病理解剖对照,假阳性7处、假阴性10处;SCTPA共诊断栓塞肺动脉32支,假阳性6支、假阴性13支。V/Q显像、SCTPA诊断实验家兔肺栓塞的灵敏度分别为74.4%、66.7%,特异性分别为94.4%和95.2%,准确性分别为89.7%和88.5%。结论肺通气/血流灌注显像诊断肺栓塞的灵敏度和准确性高于64层螺旋CT肺动脉造影,而特异性稍低,但无统计学差异。

Objective To evaluate the sensibilities and specificities of diagnosis for acute pulmonary embolism with perfusion/ventilation imaging（V/Q） or 64-slice computer tomography pulmonary angiography（SCTPA）.Methods Fourteen experimental rabbits were randomly divided into 2 groups,that is,experimental group（n=12）,and control group（n=2）.The rabbits of experimental group were further equally randomized into 4 subgroups,2-hour group,24-hour group,3-day group and 7-day group.The animal model of acute pulmonary embolism were prepared by jugular vena catheter using sponges as emboli.The rabbits of control group received an injection of normal saline via catheter.Pulmonary perfusion/ventilation imaging and pulmonary angiography were performed after the operation,then the rabbits were killed at the corresponding time points and the pulmonary tissue were pathological inspected to search and record the numbers and location of emboli.The control group rabbits were killed in 24 h and 3 d respectively for pathological observation.Results One rabbit of experimental group died during the operation,and the left 11 of 12 rabbits were made as acute pulmonary embolism model successfully.Totally 165 pulmonary arteries were anatomized after imaging diagnosis.Forty-three emboli were found and 39 pulmonary embolisms were made.V/Q imaging detected 36 segmental pulmonary arteries embolism,and another 10 embolisms were missed and 7 embolisms were false.SCTPA diagnosed 32 embolism arteries,another 13 embolisms were missed and 6 embolisms were misdiagnosed.The total sensibilities,specificities and accuracies were 74.4%,94.4% and 89.7% respectively for V/Q imaging,and 66.7%,95.2% and 88.5%,respectively for SCTPA in diagnosis of pulmonary artery embolism.Conclusion The sensitivity and accuracy for diagnosing pulmonary embolism with pulmonary perfusion/ventilation imaging are superior than 64-slices computer tomographic pulmonary angiography,but inferior in the specificity.However,there is no statistical difference.