| Part ICreation of Acute Peripheral Pulmonary Embolism Model on rabbit [Purpose] To investigate the stability and successful rate of rabbit acute pulmonary embolism model with autologous clots which contain sponge gelatin. [Methods]Using venous blood from 17 New Zealand rabbits, which mixed with gelatin sponge pieces completely, The formed clot bathe in water at 70?for about 10 minutes. Rabbits underwent pulmonary embolism models by injected autologous clots into right atria by external jugular vein catheter. The clots obstructed pulmonary arteries with flowing blood. Rabbits were killed in appointed time(in 2, 24hours, 3, 7, 21 days ),Pulmonary arteries were anatomized to find whether embolism occurred, to study its manifestation under microscopy.[Results] 14 of 17 rabbits were alive after clot injection.3 of them died, More than one embolism can be found on every rabbit.Altogether 50 embolus were infused, 48 embolus were found in anatomy, 2 of 4 embolus were dissolved in 21 days group, Ratio of incomplete embolus dissolution is 96.0%, The succession rate of peripheral PE models is 82.35% (14/17) , The location of embolus vary at different stage. At early stage of PE(the 2hours,24 hours groups),The majority obstruction site located segmental pulmonary arteries; at middle stage, The majority obstruction site located segmental and subsegmental arteries, at end stage, embolus moved to distal branch of subsegmental pulmonary arteries, partial embolus organized. [Conclusion] The method ofcreation of acute pulmonary embolism animal model is high successful rate, stable and practical.Part II Study of Rabbit Model of Acute Peripheral Pulmonary Embolism: CTManifestations and Pathologic Foundation[Purpose]To investigate CTPA manifestations and pathological foundation of acute peripheral pulmonary embolism on rabbit model. To assess the diagnostic value of CTPA in the diagnosis of rabbit's peripheral PE, small branches of pulmonary arteries, and its ability of displaying for the hypo-perfusion parenchyma area. [Materials and Methods] 14 Rabbits pulmonary embolism models divided 5 groups, all rabbits performed CTPA and CT plain scan and/or were killed by schedule. The normal pulmonary parenchyma and abnormal pulmonary tissue underwent pathologic study. Based on pulmonary arterial anatomy golden standard, we evaluate the diagnostic efficiency of CTPA in the diagnosis of rabbit's peripheral PE The CT values in normal pulmonary parenchyma and obstructed hypo-perfusion area were measured on CT scan. The difference of CT values underwent statistical analysis. [Results]: 14 Rabbits peripheral pulmonary embolism models enter study. The direct sign of PE were filling defects within opacified pulmonary arteries including complete occlusion(24,58.54%),central type(4,9.76%), mural type with acute angle to the wall(ll, 26.83%),mural type with blunt angle(2, 4.88%),336 pulmonary arteries branches which size is larger than 2 mm were anatomized in 14 rabbits, Altogether 48 thrombus of 50 were found,41 of them were diagnosed correctly on CTPA exam. Based on pulmonary arterial anatomy golden standard, the sensitivity and positive predictive value were 85.42%, 89.13%, respectively. The indirect signs of PE on CTPA were found on 14 rabbits model: Westermark's sign (9,64.29%), Ground glass opacity shadow(8,57.14%), consolidation(5,35.71%), which include simple consolidation and pulmonary infarction. Mosaicsign(3,21.34%), pleural effusion(2,14.29%). Different pulmonary parenchyma abnormalities has different pathologic foundation: Mosaic sign and Westermark's sign indicate no abnormalities on pulmonary tissue under microscopy. Ground glass opacity indicate non-infarct alveolus exudation; Simple consolidation shadows indicate pulmonary hemorrhage, without pulmonary interstitial destruction., pulmonary infarction accompany pulmonary interstitial destruction. For 14 rabbits which performed plain CT sc...
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