Proximal Interruption of the Pulmonary Artery.

Proximal interruption of the pulmonary artery (PIPA) is an uncommon developmental anomaly resulting in underdevelopment of the proximal portion of the pulmonary artery with preservation of the intrapulmonary segments. Clinical presentation ranges between an asymptomatic incidental finding to massive hemoptysis. When findings suggestive of PIPA are present radiographically, the diagnosis of PIPA can be definitively diagnosed with computed tomography or magnetic resonance pulmonary angiography. Other imaging modalities, such as nuclear perfusion scan and catheter angiography can help in the diagnosis.