动脉性肺隔离症的多层螺旋CT诊断

目的 评价动脉性肺隔离症(AS)的MSCT影像特征.方法 回顾性分析5例AS患者的MSCT影像资料,5例均行MSCT增强扫描,并进行3D图像重组,分析异常体循环动脉(ASA)、肺动静脉、支气管和肺实质的影像特征.结果 5例均可见单支粗大的ASA从降主动脉发出,迂曲扩张,先向下随即朝上朝前外,供血左下叶基底段,ASA供血区正好与肺动脉供血缺如区一致,肺静脉明显增粗.4例为典型AS,有典型的ASA,与左下肺静脉(IPV)紧贴,2支跨过IPV前方下行,至前内基底段,2支在IPV后方下行,至外后基底段;受累肺体积缩小,血管断面增多、增粗.在肺动脉供血与ASA供血移行区有一个特征性的乏血管带,其内支气管缺乏血管伴行.1例为不典型AS,受累肺合并先天性支气管闭锁.结论 AS有特征性的MSCT表现,典型表现可以直接诊断,不典型表现需要结合3D后处理图像仔细分析.

Multi-slice spiral CT diagnosis of arterial sequestration

Objective The purpose of this study was to present the characteristic features on MSCT angiography of arterial sequestration.Methods The MSCT images of 5 patients with arterial sequestration were retrospectively reviewed All patients underwent MSCT contrast-enhanced angiography.3D rendering was made to evaluate the lung parenchyma,bronchial system,and vascular anatomy.Results All S cases demonstrated the anomalous systemic artery(ASA)as an isolated and tortuous artery arising from the descending thoracic aorta,taking a sigmoid course and running along with airway,entering the basal segments of the left lower lobe.The inferior pulmonary vein(IPV)was significantly engorged.The typical AS was diagnosed in 4 patients.Its ASA intercrossed with the IPV and two branches entering segments 7 and 8 over the IPV,and two branches entering segments 9 and 10 under the IPV.The volume of involved lung shrunk with the artery markedly engorged.A characteristic avascular section was found between the pulmonary artery supplying area and the ASA supplying area,and the bronchi did not accompany the arteries.One was diagnosed atypical AS because of coexistence with bronchial atresia.Conclusion The arterial sequestration had characteristic MSCT findings.The typical type can be definitely diagnosed,but the atypical type needs further three-dimensional analysis.