实验性急性肺栓塞的比较影像学研究

Comparative imaging study in experimental acute pulmonary embolism

目的 探讨核素肺灌注显像、增强螺旋CT及数字减影肺动脉造影对猪急性肺栓塞实验模型 (相当于人类亚肺段水平肺栓塞 )的影像学特点。方法 13头中国实验用小型猪 ,经颈静脉注射明胶海绵栓子 (直径 3 8～ 4 2mm) ,制作肺栓塞模型后进行核素肺灌注显像、增强螺旋CT和数字减影肺动脉造影 ,以病理检查为标准 ,比较 3种检查方法的灵敏度和特异性。结果 对 195个肺段(动脉段 )进行分析 ,病理诊断阳性肺段 4 6个 ,阴性肺段 14 9个。核素肺灌注显像阳性肺段 5 1个 (包括假阳性肺段 11个 ) ,灵敏度为 87% ,特异性为 93% ;增强螺旋CT阳性肺段 4 4个 (包括假阳性肺段15个 ) ,灵敏度为 6 3% ,特异性为 90 % ;数字减影肺动脉造影阳性肺段 4 7个 (包括假阳性肺段 2个 ) ,灵敏度为 98% ,特异性为 99%。核素肺灌注显像病变检出率比增强螺旋CT高 (P <0 0 5 ) ,但与数字减影肺动脉造影相比差异无显著性 (P >0 0 5 )。增强螺旋CT可对栓子进行准确定位。结论 核素肺灌注显像对猪肺段 (相当于人类亚肺段 )肺栓塞的探测优于增强螺旋CT ,而后者对栓子定位优于前者 ;数字减影肺动脉造影对猪肺段肺栓塞诊断能力最强 ,但有创 ,应用受限。

Objective To evaluate the diagnostic characteristics of radionuclide pulmonary perfusion imaging,enhanced spiral computed tomography,and digital subtraction pulmonary angiography in acute experimental segmental pulmonary embolism (corresponding to human subsegmental pulmonary embolism). Methods Acute pulmonary embolism model was established in thirteen Chinese small type pigs by injecting glutin embolus (the diameter of the embolus was 3.8 to 4.2 mm) into pulmonary artery via jugular vein,and then radionuclide pulmonary perfusion imaging,enhanced spiral computed tomography and digital subtraction pulmonary angiography were performed. The results of sensitivity and specificity of three kinds of imaging methods were compared with the pathological findings. Results Out of 195 segmental pulmonary arteries,abnormalities were found in forty-six segmental pulmonary arteries by pathological study. Abnormalities were detected in fifty-one segmental pulmonary arteries by pulmonary perfusion imaging,with sensitivity of 87%,specificity 93%. Filling defect was demonstrated in forty-four segmental pulmonary arteries by enhanced spiral computed tomography,with sensitivity of 63%,specificity 89%. Abnormalities were displayed in forty-seven segmental pulmonary arteries by digital subtraction pulmonary angiography,with sensitivity of 98%,specificity 99%. Pulmonary perfusion imaging was superior to enhanced spiral computed tomography ( P <0.05) in diagnosis of pulmonary embolism,but there was no significant difference between pulmonary perfusion imaging and digital subtraction pulmonary angiography in diagnosis of pulmonary embolism ( P >0.05). Conclusions Pulmonary perfusion imaging is a noninvasive technique for diagnosis of pulmonary embolism which is superior to enhanced spiral computed tomography in detecting of experimental acute segmental pulmonary embolism (corresponding to human subsegmental pulmonary embolism),but the localization of embolus is more accurate by enhanced spiral computed tomography. Combination of three kinds of imaging methods may significantly improve the diagnostic accuracy for pulmonary embolism.