Pediatric 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 that bypasses the capillary bed
  • Imaging 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 the aneurysmal part of the feeding artery and the 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 or microscopic telangiectasia and not due to hemorrhage
    — Multiple in 33% of patients
  • DDX:
  • Complications:
  • Treatment: Required if symptomatic or if feeding artery is > 3 millimeters in diameter
  • Clinical: Presents with dyspnea due to right-to-left shunting or embolic events due to paradoxical emboli

Radiology 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.

Radiology Cases of Pulmonary Arteriovenous Malformation Causing Cerebral Abscess

CT of pulmonary arteriovenous malformation causing multiple brain abscesses
Axial MRI with contrast of the brain (above) shows multiple ring enhancing lesions in the cerebrum. Axial CT with contrast of the chest (below left) shows multiple necrotic mediastinal lymph nodes. Coronal CT with contrast of the chest (below right) shows a lobulated lesion in the right lower lobe with feeding and draining vessels associated with it.