Patterns of extracranial involvement in newly diagnosed giant cell arteritis assessed by physical examination, colour coded duplex sonography and FDG-PET

Abstract

The clinical spectrum of giant cell arteritis (GCA) varies from classical temporal arteritis (TA) to generalized large vessel GCA (LV-GCA) and fever of unknown origin (FUO). Extent and distribution of extracranial involvement in these different presentations of GCA is not well known, and its detection may depend on the choice of vascular imaging. In 24 patients with newly diagnosed GCA we systematically evaluated the presence and distribution of extracranial involvement by physical examination, duplex sonography (DS), and FDG-PET. Analysis of FDG-PET results was performed in comparison with 18 age-matched control-subjects scanned for oncological indications. Initial clinical diagnosis was TA in 11 patients, LV-GCA in 8 patients, and FUO in 5 patients. Clinically detectable arterial obstruction was present in 2 patients (18 %) with TA (only upper extremity), all patients with LV-GCA (upper and lower extremities) and no patient with FUO. Upper and/or lower limb large vessel vasculitis was detectable by DS in 45 % of the patients with TA and in 100 % of the patients with LV-GCA or FUO. FDG-PET confirmed upper extremity involvement in all affected patients, but had a very low specificity for lower limb involvement due to concomitant arteriosclerosis in these elderly patients. Aortitis was detectable by FDG-PET in 27 % of patients with TA and 75 - 80 % of patients with LV-GCA or FUO. The combination of thorough clinical examination and DS is able to detect symptomatic as well as asymptomatic large vessel involvement in a large proportion of patients with newly diagnosed GCA. Distribution and manifestation of large vessel involvement differs between classical TA and LVGCA or FUO. FDG-PET provided only limited additional information and did not change the clinical diagnosis in any patient.