● Clinical Presentation

● 臨床表現(xiàn)

● A 23-year-old man with recurrent pneumonia.

● 23歲男性，反復(fù)肺炎。

● Further Work-up

● 進(jìn)一步檢查

● See Images at Left

● 看左圖

● Imaging Findings

● 影像表現(xiàn)

● Click on Annotated Thumbnail to reveal caption

● 點(diǎn)擊縮略圖顯示注釋

● 1A - Annotated Caption

● 1A - 注釋說(shuō)明

● (A–C) Contrast-enhanced thoracic computed tomography. Mediastinal window (A,B) and lung window (C) images demonstrate a well-defined cavitary lesion in the left lower lobe (black arrow, C) and an abnormal vessel arising from the lateral aspect of the distal descending thoracic aorta (white arrow, A), adjacent to the cavitary lesion. An abnormal vein anterior to the aorta is also present (white arrow, B).

● （A-C）對(duì)比增強(qiáng)胸部CT?？v隔窗（A，B）和肺窗（C）圖像顯示左下肺葉的邊界清晰空洞病變（黑色箭頭，C）和遠(yuǎn)端降主動(dòng)脈外側(cè)面鄰近空洞病變區(qū)出現(xiàn)的異常血管（白色箭頭 ，A）。主動(dòng)脈前方的可見(jiàn)異常靜脈（白色箭頭，B）。

● 1B - Annotated Caption

● 1B - 注釋說(shuō)明

● (A–C) Contrast-enhanced thoracic computed tomography. Mediastinal window (A,B) and lung window (C) images demonstrate a well-defined cavitary lesion in the left lower lobe (black arrow, C) and an abnormal vessel arising from the lateral aspect of the distal descending thoracic aorta (white arrow, A), adjacent to the cavitary lesion. An abnormal vein anterior to the aorta is also present (white arrow, B).

● （A-C）對(duì)比增強(qiáng)胸部CT?？v隔窗（A，B）和肺窗（C）圖像顯示左下肺葉的邊界清晰空洞病變（黑色箭頭，C）和遠(yuǎn)端降主動(dòng)脈外側(cè)面鄰近空洞病變區(qū)出現(xiàn)的異常血管（白色箭頭 ，A）。主動(dòng)脈前方的可見(jiàn)異常靜脈（白色箭頭，B）。

● 1C - Annotated Caption

● 1C -注釋說(shuō)明

● (A–C) Contrast-enhanced thoracic computed tomography. Mediastinal window (A,B) and lung window (C) images demonstrate a well-defined cavitary lesion in the left lower lobe (black arrow, C) and an abnormal vessel arising from the lateral aspect of the distal descending thoracic aorta (white arrow, A), adjacent to the cavitary lesion. An abnormal vein anterior to the aorta is also present (white arrow, B).

● （A-C）對(duì)比增強(qiáng)胸部CT?？v隔窗（A，B）和肺窗（C）圖像顯示左下肺葉的邊界清晰空洞病變（黑色箭頭，C）和遠(yuǎn)端降主動(dòng)脈外側(cè)面鄰近空洞病變區(qū)出現(xiàn)的異常血管（白色箭頭 ，A）。主動(dòng)脈前方的可見(jiàn)異常靜脈（白色箭頭，B）。

● Differential Diagnosis

● 鑒別診斷

● Pulmonary sequestration (PS): A parenchymal mass or cavitary lesion in a lower lobe with systemic arterial supply and systemic venous drainage is characteristic of a PS.

● 肺隔離癥（PS）：由系統(tǒng)動(dòng)脈供血和系統(tǒng)靜脈引流的下葉實(shí)質(zhì)性腫塊或空洞病變是PS的特征。

● Lung abscess: A lung abscess in a lower lobe can present with an appearance similar to that of a PS. Key elements for differentiating between these conditions are the vascular supply and drainage of the abnormality. A pulmonary abscess in a previously normal lung should have a normal pulmonary supply and normal venous return.

● 肺膿腫：下葉的肺膿腫可呈現(xiàn)類似于PS的外觀。區(qū)分這些情況的關(guān)鍵因素是異常的供血和引流血管。發(fā)生于正常肺組織的肺膿腫應(yīng)具有正常的肺供血和靜脈回流。

● Intrapulmonary bronchogenic cyst: A bronchogenic cyst, when located in the pulmonary parenchyma, can also resemble a PS. Again, the vasculature helps in distinguishing between these abnormalities.

● 肺內(nèi)支氣管囊腫：位于肺實(shí)質(zhì)內(nèi)的支氣管囊腫也可以類似于PS。再次，脈管系統(tǒng)有助于區(qū)分這些異常。

● Essential Facts

● 基本事實(shí)

● PS is an anomaly of tracheobronchial branching, with an abnormal bronchial connection or obstruction and abnormal systemic arterial supply to the affected lung.

● PS是氣管支氣管分支的異常，支氣管連接或阻塞異常，并且病變肺是異常的系統(tǒng)動(dòng)脈供血。

● Common clinical presentations include pneumonia, recurrent infection, cough, and hemoptysis.

● 常見(jiàn)的臨床表現(xiàn)包括肺炎，反復(fù)感染，咳嗽和咯血。

● Bronchiectasis, atelectasis, air-fluid levels, and emphysema in the sequestered lung are common.

● 常并支氣管擴(kuò)張，肺不張，氣液平面和肺氣腫。

● Classically, PS has been divided into two major categories: intralobar and extralobar.

● 傳統(tǒng)上，PS被分為兩大類：葉內(nèi)型和葉外型。

● Intralobar sequestration is the most common type (75%), may affect either lower lobe, and is likely congenital.

● 葉內(nèi)型隔離是最常見(jiàn)的類型（75％），可能累及任何一個(gè)下葉，可能是先天性的。

● Intralobar sequestration is probably acquired as a consequence of bronchial obstruction and receives arterial supply from the descending aorta.

● 葉內(nèi)型肺隔離癥可能源于支氣管阻塞，并從降主動(dòng)脈接受動(dòng)脈供血。

● Extralobar sequestration is likely congenital, is seen predominantly in males, and commonly presents relatively early in life. The vast majority of extralobar sequestrations are located in the left lower lobe (90%).

● 葉外型隔離癥可能是先天性的，主要見(jiàn)于男性，并且通常在年幼時(shí)較早發(fā)病。絕大多數(shù)的葉外型隔離癥位于左下葉（90％）。

● An extralobar sequestration receives its arterial supply from either the thoracic or the abdominal aorta.

● 葉外型隔離癥從胸主動(dòng)脈或腹主動(dòng)脈接受其動(dòng)脈供血。

● A large number of extralobar sequestrations are associated with other abnormalities, such as left posterior diaphragmatic hernia (80%), congenital heart disease, and congenital cystic adenomatoid malformation, or they may be connected to the gastrointestinal tract (esophagus or stomach).

●  大量的葉外型隔離癥與其他異常相關(guān)，如左后膈疝（80％），先天性心臟病和先天性囊性腺瘤樣畸形，或者它們可能與胃腸道（食道或胃）連接。

● Other Imaging Findings

● 其他影像表現(xiàn)

● No Other Imaging Findings

● 沒(méi)有其他影像表現(xiàn)

● Pearls and Pitfalls

● 經(jīng)驗(yàn)與教訓(xùn)

●  Intralobar sequestrations have venous drainage through the pulmonary venous system, whereas extralobar sequestrations have systemic venous drainage through the azygos vein, hemiazygos system, or inferior vena cava.

● 葉內(nèi)型隔離癥通過(guò)肺靜脈系統(tǒng)進(jìn)行靜脈引流，而葉外型隔離癥通過(guò)奇靜脈、半奇靜脈或下腔靜脈引流至系統(tǒng)靜脈。

● On conventional radiographs, PS can have a wide spectrum of imaging findings, including a solid mass, a cystic lesion, and an air-fluid level, which can be confused with pneumonia, abscess, cyst, and tumor.

● 在常規(guī)X線片上，PS可以有多種影像學(xué)表現(xiàn)，包括實(shí)性腫塊、囊性病變和氣液平面，可類似于肺炎、膿腫、囊腫和腫瘤。

● Further Readings

● Berrocal T, Madrid C, Novo S, Gutiérrez J, Arjonilla A, Gómez-León N. Congenital anomalies of the tracheobronchial tree, lung, and mediastinum: embryology, radiology, and pathology. Radiographics. 2004;24(1):e17.

● Bolca N, Topal U, Bayram S. Bronchopulmonary sequestration: radiologic findings. Eur J Radiol. 2004;52(2):185-191.

● Evrard V, Ceulemans J, Coosemans W, et al. Congenital parenchymatous malformations of the lung. World J Surg. 1999;23(11):1123-1132.

● Zylak CJ, Eyler WR, Spizarny DL, Stone CH. Developmental lung anomalies in the adult: radiologic-pathologic correlation. Radiographics. 2002;22:S25-S43.