Anatomy and radiographs.—The right paratracheal stripe is a vertical, linear, soft-tissue opacity less than 4 mm wide. It corresponds to the right tracheal wall, contiguous mediastinal tissues, and adjacent pleura (Fig 64). The stripe is 3–4 cm in height and extends from approximately the level of the medial ends of the clavicles to the right tracheobronchial angle on a frontal chest radiograph (120). It is seen in up to 94% of adults but is widened or absent in individuals with abundant mediastinal fat. The commonest pathologic cause of widening, deformity, or obliteration of this stripe is paratracheal lymph node enlargement. [Fleischner Society]