螺旋CT肺动脉造影诊断肺小动脉血栓的实验研究

Spiral CT angiography for detection of small pulmonary thrombi: an experimental study

目的 评价螺旋CT肺动脉造影 (spiralCTpulmonaryangiography ,CTPA)诊断犬肺小动脉血栓栓子 (直径 2 5～ 3 5mm)的应用价值。方法 2 3条实验犬行CTPA空白对照后 ,制成犬自体血块肺动脉栓塞模型 ,先后行CTPA与X线肺动脉造影 (X raypulmonaryangiography,XPA)检查 ,由 2名医生在工作站上分析所获图像 ,并与犬肺病理解剖结果对照 ,评价CTPA与XPA对肺动脉血栓栓塞的诊断价值。结果 2 2条犬完成实验全过程 ,病理解剖发现肺动脉内栓子 110个 ,与人工注入栓子数目相符 ,均位于肺动脉的段或亚段水平 ,其中 10 7个位于扫描野内。CTPA发现栓子 90个 ,诊断肺动脉内小血栓栓子的敏感度为 84 1% ,阳性预测值为 93 8% ;XPA发现栓子 82个 ,敏感度为 76 6% ,阳性预测值为 94 3 %。

Objective To evaluate the diagnostic value of subsecond spiral CT pulmonary angiography (CTPA) in detecting the small pulmonary thrombi (diameter 2.5～3.5 mm) in canine models. Methods CTPA were acquired for blank control study in 23 dogs, and then pulmonary embolism models of the dogs were made by autologous blood clots. After that, CTPA and X-ray pulmonary angiography (XPA) were done successively. The images were evaluated on a workstation by two radiologists and the image findings were compared with that of pathological dissections. Results 22 pulmonary embolism models were successfully made in this study, and the 110 thrombi were found during pulmonary artery dissections. The number of the thrombi was in accordance with that injected, and all thrombi located in segment and sub-segment of pulmonary arteries, of which 107 thrombi were in the field of view (FOV). 90 thrombi were found with CTPA, whereas 82 thrombi were found with XPA. For the diagnosis of small pulmonary thrombi, the sensitivity of the CTPA and XPA was 84.1%, 76.6%, respectively, and the positive predictive values were 93.8% and 94.3%, respectively. Conclusion Spiral CT angiography has higher diagnostic value for detection of small experimental pulmonary thrombi in dogs.