RUL=right upper lobe T= Thoracic vertebra
Figure 1 Normal anatomy of trachea (a), tracheal stenosis with
normal branching of major bronchi (b), tracheal stenosis with an
accessory tracheal right upper lobe branch (c) and tracheal stenosis
with partial supply of right upper lobe (apical branch) by tracheal
bronchus (d). RUL = right upper lobe. LMB= left main bronchus. RMB =
right main bronchus.