68Ga-FAPI PET/CT Versus 18F-FDG PET/CT for the Evaluation of Disease Activity in Takayasu Arteritis

Abstract Evaluation of disease activity in Takayasu arteritis (TA) is challenging because clinical, biological, and imaging data do not always correlate. In this case, a 19-year-old woman with TA underwent 18 F-FDG PET/CT for evaluating disease activity. However, no abnormal 18 F-FDG uptake was observed in the large arteries. Follow-up with 68 Ga-FAPI PET/CT showed intense activity in the mildly thickened walls of bilateral carotid, subclavian arteries, and thoracic and abdominal aorta. This case presented an example where 68 Ga-FAPI outperformed 18 F-FDG for detecting active inflammation of TA. Therefore, 68 Ga-FAPI PET/CT may allow monitoring of disease activity and facilitate selecting the optimal therapy for TA patients.