Thrombosis of the right internal jugular vein is noted (white arrow). There is hyperemia of the vein wall, and the vein is dilated to 2.9 × 2.4 cm. There is extension of the thrombus into the subclavian vein. There is extension of thrombus into the innominate vein as well. There is a mediastinal soft tissue density measuring 4.1 × 2.8 cm (green arrow). The right vertebral artery is diminutive in size. The basilar artery is patent and the vertebral arteries are patent. The left internal jugular vein is patent. The origins of great vessels are patent. The thrombus in the right jugular vein extends up to the level of the skull base. The extension of the thrombus into the sigmoid sinus on the right is to be noted. The dilated jugular vein is exerting mass effect on the adjacent thyroid gland.