Contrast-Enhanced Ultrasound of the Carotid Artery in Patients With Large Vessel Vasculitis: Correlation With Positron Emission Tomography Findings

ObjectiveTo assess the findings of contrast-enhanced ultrasound (CEUS) of carotid arteries in patients with large vessel vasculitis (LVV) and to compare them with those observed using F-18-fluorodeoxyglucose-positron emission tomography ((18)FDG-PET). MethodsA total of 31 consecutive patients with LVV (14 with Takayasu arteritis, 17 with giant cell arteritis with large vessel involvement) underwent both PET/computed tomography and carotid artery color Doppler ultrasound (CDUS) for a total of 35 combined assessments. Right carotid artery CEUS was performed after CDUS in all assessments. Kerr's criteria, a complete clinical examination, and acute phase reactants were simultaneously evaluated. The intensity of vascular uptake and vascularization of the carotid artery wall were compared. ResultsTen F-18-FDG/PET scans showed active vascular F-18-FDG uptake (visual grade 2) in the right carotid artery. CEUS demonstrated severe vascularization (grade 2) within the right carotid artery wall in 12 examinations. The carotid CEUS vascularization grade significantly correlated with vascular F-18-FDG uptake (P<0.001) and maximum standardized uptake value (SUV) in the right carotid artery/mean SUV in the superior vena cava (P=0.001). When active vascular F-18-FDG uptake (2) was considered the gold standard for defining vascular inflammation, carotid CEUS had a sensitivity of 100% (95% confidence interval [95% CI] 65-100) and a specificity of 92% (95% CI 72-99). The positive likelihood ratio was 12.5 (95% CI 3.3-47.2). Severe vascularization at CEUS and active vascular F-18-FDG uptake were significantly more frequent in active disease according to Kerr's criteria compared to inactive (P=0.001 and P=0.002, respectively). ConclusionCarotid CEUS vascularization grade and the grade of vascular inflammation on F-18-FDG-PET were correlated in patients with LVV.