Hemithoracic volume loss can occur from a number of situations. These include:
Congenital
- pulmonary hypoplasia (unilateral)
- isolated unilateral pulmonary artery agenesis
- skeletal deformities - e.g. kyphosis,
Acquired
Infection in childhood
Other infective/inflammatory conditions
- granulomatous infection
- granulomatosis with polyangiitis 2 - rare
- tuberculosis (with excessive fibrosis on one side)
- malignant contracting conditions
Surgical
- post lobectomy
- pre-existing pulmonary fibrosis with transplant of opposite lung
- post-therapeutic intervention - e.g. bronchial valve surgery 3
Other
Mimics
- congenital lobar hyperinflation - makes opposite normal lung look smaller