Evidence of Subclavian Vein Thrombosis on First-Pass ¹⁸FDG PET in a Patient with Relapsing Upper Mediastinum Lymphoma

Baseline ¹⁸F-FDG PET was performed in a 74-year-old patient with relapsing upper mediastinum lymphoma. Left subclavian thrombosis was suspected on prior contrast-enhanced CT. Dynamic PET imaging was achieved during 3 min after IV injection of ¹⁸F-FDG to the left arm in order to further assess left subclavian vein permeability. The 20-s dynamic frame at 1 min after injection confirmed the absence of flow in the left subclavian vein and evidenced the derivation of ¹⁸F-FDG through left axillary, then superficial, then right internal mammary collaterals to the superior vena cava, hence confirming the subclavian thrombosis.