多层螺旋CT在肺动脉栓塞诊断中的应用价值

目的 研究多层螺旋CT在肺动脉栓塞诊断中的临床应用，着重研究亚段肺动脉栓塞的诊断价值。方法 共34例，下肢深静脉血栓16例，近期大手术史11例，肺癌1例，不明原因6例。34例均使用GE Light Speed Plus多层螺旋CT(MSCT)行平扫及造影增强扫描，1次采集4层图像。结果 分析34例共1824支肺动脉分支，其中507支肺动脉分支显示了栓塞，占27．8％。在680支肺段动脉中，246支显示了栓塞，占36．2％；而亚段肺动脉1041支中，141支显示了栓塞，占13．5％。平扫肺动脉栓塞的间接征象为肺纹理稀少19例，肺动脉高压2例，胸水16例，胸膜下梗死灶共41个，梗死灶多发11例，单发12例，双肺6例。1例慢性栓塞栓子钙化，极为少见。造影增强后肺动脉栓塞的直接征象为不同程度的肺动脉分支充盈缺损。充盈缺损有4种表现形式：中心型57支，偏心型160支，附壁血栓131支，完全阻塞型159支。结论 多层螺旋CT肺动脉造影是诊断肺动脉栓塞的快速、有效、无创伤的诊断方法，尤其对亚段肺动脉栓塞是一种先进的方法，可以代替肺动脉造影，可与电子束CT媲美，可能成为诊断肺动脉栓塞的首选方法。

Clinical application of multislice spiral CT in the diagnosis of pulmonary embolism

Objective To study the application of multislice spiral CT (MSCT) in the diagnosis of pulmonary embolism (PE) with emphasis on subsegmental PE Methods Thirty four cases with both sexes of PE were analyzed The average age was 56 years, from 33 to 77 years The history included deep venous thrombosis in 16 cases, post operation in 11 cases, lung cancer in one case, and with unknown reason in 6 casess 34 patients underwent MSCT (Lightspeed plus, GE) with acquisition of 4 slices for one scan, the slice thickness was 2 5 mm, with all length 150-170 mm and scan time 0 6-0 8 s Nonionic contrast media (100 ml, 300 mg I/ml) was administered, the flow rate was 3 5 ml/s, the delay time was 12-15 s, and the scan time was 17-20 s The reconstruction of MSCTA was from MIP, SSD, VR and endoscopy Results In 34 patients studied by MSCT and MSCTA, pulmonary arteries were demonstrated in 1 824 branches, and PE was detected in 507 branches (27 8%) For segmental pulmonary arteries, 36 2% showed PE, and for subsegmental pulmonary arteries, 13 5% showed PE The indirect signs of the plain MSCT included: reduced pulmonary vascular markings (19 cases), pulmonary hypertension (2 cases), pleural effusion (16 cases), subpleural infarction (41 foci) On post contrast MSCTA, the direct sign was the filling defect in the pulmonary arteries branches at various degrees, and four forms of the filling defect included central filling defect in 57 branches, eccentric filling defect in 160 branches, embolism attached to the wall of host artery in 131 branches, total occlusion of the pulmonary arteries in 159 branches Conclusion MSCT is a fast, effective, and non invasive diagnostic method for PE It may replace the pulmonary angiography (DSA) and it is as good as EBCT It will be the gold standard for diagnosis of pulmonary embolism