18F-Fludeoxyglucose PET/CT in the evaluation of large-vessel vasculitis

British Journal of Radiology (2012) 85, e188-e194 

¹⁸F-Fludeoxyglucose PET/CT in the evaluation of large-vessel vasculitis: diagnostic performance and correlation with clinical and laboratory parameters  N D Papathanasiou Correspondence: Dr Jamshed Bomanji, Institute of Nuclear Medicine, University College Hospital, 235 Euston Road, London NW1 2BU, UK. E-mail: jamshed.bomanji@uclh.nhs.uk

Abstract

Objective: To investigate the diagnostic performance of ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/CT in patients with suspected large-vessel vasculitis and its potential to evaluate the extent and activity of disease.

Methods: 78 consecutive patients (mean age 63 years; 53 females) with suspected large-vessel vasculitis were evaluated with ¹⁸F-FDG PET/CT. ¹⁸F-FDG uptake in the aorta and major branches was visually graded using a four-point scale and quantified with standardised uptake values (SUV_max). According to clinical diagnosis, patients were classified into three groups: (a) steroid-naïve, large-vessel vasculitis (16 patients), (b) vasculitis on steroid treatment (18 patients) and (c) no evidence of vasculitis (44 patients). Analysis of variance and linear regression were used to investigate the association of ¹⁸F-FDG uptake with clinical diagnosis and inflammatory markers.

Results: ¹⁸F-FDG PET/CT was positive (visual uptake ≥2; equal to or greater than liver) in all patients with steroid-naïve, large-vessel vasculitis. The thoracic aorta, the carotid and the subclavian arteries were most frequently involved. 

Conclusion: ¹⁸F-FDG PET/CT can detect the extent and activity of large-vessel vasculitis in untreated patients and is unreliable in diagnosing vasculitis in patients on steroids.