Unique imaging observations in an incidentally detected bilateral upper lobe agenesis

Bilateral upper lobe pulmonary agenesis is an uncommon congenital anomaly usually detected incidentally in adulthood. Plain radiographic findings are non-specific and subtle, and diagnosis is rarely suspected on conventional radiography despite available subtle clues. Chest CT, done for other indications, is capable of detecting this anomaly. Contrast-enhanced CT is the modality of choice to diagnose and show all features of pulmonary lobar agenesis. Knowledge of the wide spectrum of associated pulmonary anomalies is required in the management of patients with congenital heart disease.