Pulmonary artery involvement can occur in about half of the patients suffering Takayasu arteritis. Increased FDG activity in the aorta and its main branches in patients with Takayasu arteritis on PET/CT had been well-reported. However, the FDG PET/CT appearance of pulmonary artery involvement in Takayasu arteritis is less known. We present FDG PET/CT findings in a 37-year-old patient with known Takayasu arteritis. The images showed rim-like FDG activity in opacities in the left lung, which was later proven due to narrowed left main pulmonary artery.