肺动脉栓塞的多层螺旋CT诊断与鉴别

目的研究肺动脉栓塞多层螺旋CT肺血管成像的影像表现，探讨与肺动脉栓塞表现相似疾病的鉴别，提高肺动脉栓塞诊断与鉴别诊断的水平。方法对21例肺动脉栓塞（1例为瘤栓）患者行多层螺旋CT肺动脉成像检查，图像采用10mm层厚，10mm层间距，和1．25层厚，0．625mm层间距进行重建，所获的数据传送至工作站运用MPR、MIP、VR技术后处理。结果20例中（不包括1例肺动脉肿瘤），双侧肺动脉受累18例，单侧2例，病变累及131支肺动脉及分支。其中发生于左及右肺动脉远端18支，肺叶动脉38支、肺段动脉50支、肺段以下25支，CT显示的直接征象为肺动脉及分支血管内不同程度的充盈缺损，增强扫描不强化。充盈缺损依形态可分为4种：中心型（25支）、偏心型（61支）、附壁型（25支）、完全闭塞型（20支）。并存间接征象为主肺动脉及左右肺动脉增宽，局限性肺内灌注不均匀，肺梗死，胸腔积液及右房、右室增大。结论肺动脉栓塞在CT图像上形态多样，病变范围广泛，双侧发病多于单侧，主肺动脉受累少见。多层螺旋CT肺血管成像对本病的诊断有独特的优势，该方法能清晰显示肺动脉栓塞的直接征象和间接征象。为诊断及鉴别诊断提供可靠的影像学资料。

The diagnosis and differentiation of pulmonary embolism with MSCT

Objective To study the imaging features of multi-slice CT（MSCT） in the pulmonary embolism （PE） , to explore the discrimination of disease which were similar with PE in feature, and to improve the level on the diagnosis and differentiation of PE. Methods 21 cases with PE （ embolus consisting of tumor in 1 case） were examined with MSCT pulmonary angiography, the reformation images consisted of 10 mm slices, with 10 mm reconstruction intervals and 1.25 mm slices, with 0. 625 mm reconstruction intervals. Then all the data were reconstructed by MPR, MIP, VR in the workstop. Results There were 20 cases of PE （ pulmonary thromboembolism）, 18 cases of bilateral pulmonary arteries, and 2 cases of unilateral pulmonary arteries. 131 branches of pulmonary embolism were identified, including 18 left and right distant pulmonary arteries, 38 lobar arteries, 50 segmental pulmonary arteries and 25 subeqmental pulmonary arteries. On post-contrast MSCTA, the direct sign was the filling defect in the PE branches at various degrees, and according to different shapes, there were four forms of filling defect： central filling defect （25 branches）, eccentric filling defect （61 branches） , embolism attached to the wall of host artery （25 branches） , and total occlusion of the pulmonary arteries （20 branches）. The indirect signs were as follows： dilated main pulmonary arteries, limited lung lack of blood, pulmonary embolism, pleural effusion, enlargement of right atrium and ventricle. Conclusion The imaging features of PE are varied, the displayed range is wide, bilateral PE are more than unilateral, and main pulmonary embolism are few. MSCT pulmonary angiography proves to be unique advantage for pulmonary embolism. This method can show the direct and indirect signs of PE clearly, and can provide sufficient diagnosis information of imaging.