周围性肺栓塞螺旋CT强化扫描肺密度测量的研究

目的　探讨螺旋CT平扫与强化扫描肺实质密度测量在周围性肺栓塞诊断中的作用。方法　 8只犬于DSA下复制为单侧周围性肺栓塞动物模型后进行螺旋CT平扫和强化扫描 ,根据DSA发现的栓塞肺动脉的位置 ,于螺旋CT平扫和强化扫描图像上分别测量栓塞区与对侧肺正常肺实质的CT值 ,比较双肺的CT值差异与净增CT值差异。结果　螺旋CT平扫栓塞区的CT值与对侧正常肺实质的CT值之间无明显差异 (P >0 .0 5 ) ;螺旋CT强化扫描显示栓塞区的CT值明显低于正常肺实质的CT值 (P <0 .0 1) ,而且栓塞区的净增CT值也明显低于正常肺实质的净增CT值 (P <0 .0 1)。结论　螺旋CT强化扫描可以发现周围性肺栓塞所致的低灌注区 ,是诊断周围性肺栓塞的重要间接征象

An experimental study of the lung in animal models of peripheral pulmonary embolism by CT densitometry

Objective To assess the value of helical CT densitometry in diagnosing peripheral pulmonary embolism (PE). Methods Eight dogs were presented with single sided peripheral PE models under DSA, then plain and contrast enhanced helical CT scans were done. According to the location of the embolic arteries observed on DSA, CT values of the embolic areas and the contralateral normal parenchyma on plain and contrast enhanced helical CT scans were measured and compared. Results On plain helical TC scans, the CT valus between the normal parenchyma and the embolic pulmonary parenchyma were similar( P > 0.05 ). On contrast enhanced helical CT scans, the CT values and the net increased CT values of the embolic areas were significantly lower than those of the normal parenchyma( P <0.01). Conclusion Contrast enhanced helical CT scans can detect the embolic low perfusion areas and then make indirect diagnosis of peripheral PE.