The tracheobronchial tree anatomy can also be valuable in determining situs. These images are 3D volume-rendered reconstruction of the airways in 4 different patients. (A) This image shows the airways of the patient with situs solitus. The right-sided bronchus is short and horizontal compared with the left-sided bronchus. (B) The tracheobronchial tree of a patient with situs inversus is shown. The right-sided bronchus is long and angled, consistent with a morphologic left bronchus, whereas the left-sided bronchus is shorter and less angled, consistent with a morphologic right bronchus. (C) This image shows a patient with right isomerism. Both bronchi are short and horizontal. This patient has tri-lobed lungs bilaterally. (D) This image, from a patient with left isomerism, shows long and angled bilateral bronchi. This patient has bi-lobed lungs bilaterally. F, feet; H, head; L, left; R, right; 3D, 3-dimensional.