Figure 7a. Right paratracheal stripe. (a) Posteroanterior chest radiograph shows the right paratracheal stripe (arrow). The azygos vein is seen at the inferior margin of the stripe at the tracheobronchial angle (arrowhead). (b) CT scan shows the right wall of the trachea with medial and lateral air–soft tissue interfaces caused by air within the tracheal lumen and right lung (arrow). These interfaces create the right paratracheal stripe (cf a). Note the position of the SVC (arrowhead), which explains why the paratracheal stripe is seen projecting through the SVC at radiography. (c) CT scan obtained at the level of the azygos arch shows that the azygos vein (arrow) disrupts the lung–tracheal wall interface at the tracheobronchial angle.