The utility of PET/CT in large vessel vasculitis

Abstract 18F-FDG PET/CT occupies a growing role in the diagnosis of large vessel vasculitis (LVV), illustrating enhanced uptake in the lining of large vessels. A retrospective single center study was conducted of patients who underwent 18F-FDG PET/CT scans between 2009 and 2019 at Sheba Medical Center, Israel. The imaging results were analyzed for evidence of LVV. We reviewed the PET/CT scans of 126 patients and identified 57 studies that either showed evidence of active LVV or that had been performed in patients previously treated for systemic vasculitis. In 6 patients with fevers of unknown origin and elevated inflammatory markers, PET/CT revealed LVV. Six of 13 patients previously treated for systemic vasculitis demonstrated persistent large vessel uptake. LVV was identified in 8 patients with other autoimmune diseases, and in 4 diagnosed with infectious aortitis. In 26 patients who underwent malignancy surveillance, PET/CT revealed more localized large vessel wall inflammation. Our results illustrate that PET/CT may identify large vessel wall inflammation in patients with a suspicion of LVV, and incidentally in patients who undergo malignancy surveillance. PET/CT may also help delineate the presence and extent of vessel inflammation in patients with LVV and in those with other autoimmune diseases.