Diaphragm Appearance: A Clue to the Diagnosis of Pulmonary and Extrapulmonary Pathology

The diaphragm is often overlooked or incompletely evaluated when interpreting chest radiographs. Alterations in the appearance of the diaphragm on chest radiographs such as elevation, contour abnormalities, adjacent lucency, and calcifications can offer clues to pulmonary and extrapulmonary pathology. Familiarity with common causes of these alterations facilitates the appropriate selection of additional imaging and leads to the diagnosis of both benign and life-threatening processes. This article reviews normal variations in the appearance of the diaphragm as well as those associated with pulmonary and extrapulmonary pathology.