Fig. 2.

FDG-PET findings provide information about disease activity in TAK that may influence physician assessment in specific clinical scenarios

(A) A 15-year-old female with TAK with left carotidynia, frontal headaches, fatigue and elevated levels of acute-phase reactants. These clinical symptoms were thought to be related to active disease. FDG-PET demonstrated increased FDG uptake in the left common carotid artery (arrow), consistent with active vasculitis. (B) A 33-year-old female with TAK and persistent left arm claudication. There was uncertainty as to whether this symptom represented active disease or damage, as she did not have a clear pattern of improvement or worsening over the prior several months. FDG-PET showed increased FDG uptake in the aortic arch, proximal left subclavian artery and proximal left common carotid artery (arrows), suggesting that her ongoing symptoms were from active disease and not damage. Her symptoms subsequently improved with increased treatment. (C and D) A 38-year-old female with fatigue but no other symptoms and mild elevations in levels of acute-phase reactants. On clinical assessment alone, there was disagreement whether the degree of fatigue and laboratory abnormalities represented active vasculitis. FDG-PET showed high FDG uptake in the ascending and descending thoracic aorta (C, arrows), and the abdominal aorta (D, arrow). FDG: ¹⁸F-fluorodeoxyglucose; TAK: Takayasu’s arteritis.