3D DCE MRPA诊断肺栓塞的临床应用研究

The Study of Clinical Application of Three-Dimensional Dynamic Contrast-Enhanced MR Pulmonary Angiography in the Diagnosis of Pulmonary Embolism

目的 :探讨三维动态增强磁共振肺动脉血管成像 (3DDCEMRPA)诊断肺动脉栓塞的价值及限度。方法 :先行MR平扫 ,然后应用快速梯度回波 (FFE)序列对 3 8例怀疑肺栓塞的患者进行 3DDCEMRPA扫描。参数为TR 9ms ,TE 3ms ,矩阵 2 5 6× 12 8,翻转角 2 0° ,对比剂Gd DTPA 0 .2mmol/kg快速注射。结果 :被确诊为肺栓塞的 3 0例患者 ,共发现栓塞 43处 ,其中 3例伴有肺动脉高压。肺栓塞的 3DDCEMRPA的直接征象为肺动脉内充盈缺损 (中心型、部分型、附壁型 )和肺动脉截断 (杵状、平直、锥形及鼠尾状截断 ) ;间接征象为栓塞所属肺野出现梗死灶 ,近心侧肺动脉增粗等肺动脉高压征象及少量胸腔积液。结论 :3DDCEMRPA对中心、叶和段的肺动脉栓塞的诊断价值较大 ,但它对段以下动脉栓子的显示尚有一定限度 ;3DDCEMRPA还是鉴别急性肺动脉高压 (肺栓塞引起 )和慢性肺动脉高压的一个安全有效的手段。

Objective:To assess the diagnostic value and limitation of three-dimensional dynamic contrast-enhanced MR pulmonary angiography (3D DCE MRPA) in diagnosis of pulmonary embolism.Methods:38 patients with suspected pulmonary embolism were performed 3D DCE MRPA with fast field echo (FFE) sequence.Scan parameter TR/TE:9/3ms,Matrix 256×128 and flip angle 20°.Results:43 emboli in lobar or segmental pulmonary arteries were found in 30 cases.3 out of 30 patients accompanied with pulmonary artery hypertension.The direct signs of MRPA were intravascular filling defect and complete occlusion;pulmonary infarction,enlargement of proximal pulmonary artery and a little fluid in the thoracic cavity were the indirect signs.Conclusion:In demonstrating central,lobar,and segmental pulmonary embolism,3D DCE MRPA is a safe and reliable diagnostic method,but it has limitations for detecting emboli located in subsegmental pulmonary artery;3D DCE MRPA is also a promising noninvasive imaging modality for identification the patients with acute or chronic pulmonary artery hypertension.