right central line-aqua left central line-green

In this case, the dilated neck veins are related to partial blockage of venous drainage into the subclavian system due to bilateral central lines, with surrounding clot and possible stenosis (narrowing) of the vessels. This leads to drainage via many collateral pathways, connecting to the internal mammary veins, which connect below to the inferior epigastric veins ind into the IVC. Veins in the trunk do not have valves, so blood can flow in either direction.

These images are a coronal reconstruction of the CT, shown in soft tissue windows.