The role of 18F-FDG PET/CT in the management of large-vessel vasculitis: applications and limitations in clinical practice

Introduction: 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays a key role in oncology, and it is now being used increasingly to diagnose, characterize, and monitor disease activity in inflammatory disorders, including vasculitis. Unfortunately, its role in the management of vasculitis is still not well-defined, and clinicians are often unsure how this metabolic imaging technique should be used in these diseases, although its usefulness in diagnosing large-vessel vasculitis has been clearly demonstrated.
Materials and methods: We reviewed the literature about the use of PET/CT in the management of vasculitis in an attempt to identify the applications and the limitations of this technique in clinical practice.
Results and discussion: Our literature review revealed that 18F-FDG PET/CT is a useful tool for diagnosing vasculitis (especially when the symptoms of the disease are non-specific); guiding biopsy procedures (areas with high glucose consumption); evaluating disease extension; and monitoring treatment responses. The main limitations of this method are the relatively low spatial resolution of the tomograph, which can lead to false-negative results in the presence of small-vessel vasculitis, and risk of false positive results, especially those related to the presence of atherosclerosis and to post-treatment vascular remodeling.