Pulmonary artery segment protrusion is generally a radiographic manifestation, and depression of the pulmonary artery segment on X-ray is a diagnosis of pulmonary artery protrusion. Generally, the most important manifestation of pulmonary artery segmental herniation is pulmonary hypertension, in which the pressure in the pulmonary artery continues to rise, resulting in expansion of the pulmonary artery segment, which appears as a prominent depressed foci on X-ray radiographs. In general, the presence of pulmonary hypertension requires active treatment of the primary disease, such as congenital heart disease, right-to-left shunt, Eisenmenger syndrome, or arterial catheterization, Fallot’s trichotomy, or even cardiac valvular disease, which may cause pulmonary artery protrusion and pulmonary artery hypertension. It is then necessary to actively treat the primary disease, as well as to treat it with medications that lower pulmonary pressure.