肺动静脉畸形的综合影像评价

目的 评价各种影像学检查手段诊断肺动静脉畸形的作用。材料与方法 回顾性分析11例肺动静脉畸形患者的各种影像学检查的表现、胸片、肺动静脉造影11例,CT平扫7例（增强4例）,MR扫描2例（PA、MRA）,并计算各种检查方法的敏感性。结果 肺动静脉造影发现病灶29个,病灶呈瘤样扩张的血管,有1条供血动脉和数条引流静脉,引流静脉和左房早期显影。胸片表现为肺内局限结节样影且有异常血管与肺门相连,其敏感性为79.3%(23/29）。CT表现为病灶密度均实,边界光整,并有典型的“血管蒂”征,增强扫描示病灶与肺动脉同步强化,多平面重建（MPR）有助于认识其相关血管,检查敏感性为94.4%(17/18）。MR扫描敏感性的80.8%(4/5）,对比增强肺动脉MR成像（CE MRA）可弥补常规序列的不足,有助于显示病变全貌,图像堪与肺动脉造影相比。结论 胸片可作为筛选方法,而肺动脉造影是诊断的“金标准”;CT可以提供与肺动脉造影相同的诊断信息,在某种程度上可取代肺动脉造影;MR特别是动态增强MRA不仅可以在形态上确认病灶,还可用以评价血流动力学改变和评估预后。胸片与CT是最佳的治疗后随访手段。

A Comprehensive Imaging Evaluation of Pulmonary Arteriovenous Malformation

Objective To evaluate four imaging methods in diagnosing pulmonary arteriovenous malformation (PAVM).Materials and Methods Imaging findings of PAVM in 11 patients were retrospectively analyzed. The imaging technique included chest film (n=11), pulmonary artery angiography (n=11), both plain and enhanced CT scan (n=7 and n=4, respectively), MR and MRA of pulmonary artery (n=2). The sensitivity of each imaging method was calculated.Results Pulmonary artery angiography revealed 29 PAVM lesions, which showed abnormal angioectasis, one feeding artery and several draining veins, the left atrium was displayed before the normal pulmonary vein. On chest film, the lesion presented as lobulated nodule attached to hilar region with abnormal vessels. The diagnostic sensitivity of this sign was 79.3% (23/29). On CT scan, the lesion showed homogeneous density and typical "vascular root" sign. On enhanced CT scan, the lesion showed enhancement, which changed in accordance with the enhancement of the pulmonary artery. On MPR, the whole vasculature of PAVM could be displayed. The sensitivity of CT and MRI was 94.4% (17/18) and 80% (4/5), respectively. The disadvantage of conventional MR sequence could be made up with contrast enhanced MR pulmonary angiography, which could produce images as good as angiographs and show the full view of PAVM.Conclusion In diagnosing PAVM, chest radiography can be used as a screening, while pulmonary angiography is the "gold standard" although it is an invasive study. CT scan can offer the similar information as the angiography does, and can replace the latter in some extent. MRI, especially dynamic enhanced MRA, can not only confirm the lesion morphologically, but also evaluate the hemodynamics and prognosis. Chest radiography and CT scan are the best study for follow up after treatment.