Pulmonary Arteriovenous Malformation

  • Etiology: abnormally dilated vessels provide a right-to-left shunt between pulmonary artery and vein resulting in high flow and low-resistance fistulous connection between pulmonary arteries and veins
  • CT: non-contrast shows homogeneous / well-circumscribed / non-calcified nodule or a serpiginous mass connected with blood vessels which may have associated phleboliths, contrast shows enhancement of feeding artery, the aneurysmal part, and draining vein on early-phase imaging
  • Clinical: presents with dyspnea due to right-to-left shunting or embolic events due to paradoxical emboli, multiple in 33% of patients

Cases of Pulmonary Arteriovenous Malformation

Angiogram of pulmonary ateriovenous malformation
CXR AP (upper left) shows an ill-defined mass in the right hilum. AP image from a selective injection of the right pulmonary artery from a pulmonary angiogram (upper right) shows a tangle of dilated arterial vessels comprising the mass. Arterial phase (lower left) and venous phase (lower right) AP images from a pulmonary angiogram demonstrate the early arterial appearance of the lesion and then its venous drainage back into the left atrium.