Pulmonary arteriovenous malformation, a condition most commonly associated with hereditary hemorrhagic telangiectasia, is an abnormal communication between the pulmonary artery and pulmonary vein without an intervening capillary communication. HRCT images usually show a coarse spidery appearance of the peripheral vascular markings in the lungs. More specific findings are obtained in the pulmonary angiogram where the normally invisible capillary phase is replaced by irregular vascular channels bridging the peripheral branches of pulmonary arteries and veins. The phenotype is HP_0006548 (Pulmonary arteriovenous malformation). Also known as: Pulmonary AV malformation.