Fig. 16
From: Pictorial review of the pulmonary vasculature: from arteries to veins
Pulmonary venous collaterals. a Axial contrast-enhanced CT image demonstrates upper right lobe squamous cell carcinoma (*) with metastatic disease obstructing the superior vena cava and stent (black arrow). Note extensive collateral formation (white arrows). b Axial CT image showing high-density contrast flow into the pulmonary venous system (black arrow) secondary to collateral formation (white arrows) with a right-to-left shunt in the setting of superior vena cava obstruction