Proximal absence of the right pulmonary artery in the adult: computed tomography and magnetic resonance findings.

Proximal absence of the right pulmonary artery is an asymptomatic congenital anomaly that must be considered when a small lung is present. This report describes two cases in adults in which computed tomography and magnetic resonance imaging provided morphologic data and flow data leading to the diagnosis and obviating the need for more invasive procedures.