Enlargement of collateral vessels (arteries, veins) |
Coarctation of aorta |
Interrupted aortic arch |
Subclavian artery obstruction (Takayasu’s disease) |
Blalock–Taussig shunt (upper two ribs) |
Superior vena cava obstruction |
Intercostal nerves (neurogenic tumours) (schwannoma, neurofibromatosis type 1) |
Hyperparathyroidism |