- 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 that bypasses the capillary bed
- CT: non-contrast shows homogeneous / well-circumscribed / non-calcified nodule or a serpiginous mass connected with blood vessels which may have associated phleboliths, contast shows enhancement of feeding artery / the aneurysmal part / draining vein on early-phase imaging with the feeding artery being smaller in diameter than the draining vein, surrounding ground glass opacity may be present and is due to vascular hyperplasia / microscopic telangiectasia and not due to hemorrhage
- Treatment: required if symptomatic or if feeding artery is > 3 mm in diameter
- Clinical: presents with dyspnea due to right-to-left shunting or embolic events due to paradoxical emboli, multiple in 33% of patients
Radiology Cases of Pulmonary Arteriovenous Malformation
