OBJECTIVE: To define the specificity and extent of duplex sonography (DS) findings suggestive of vessel wall inflammation in patients with giant cell arteritis (GCA). METHODS: Patients admitted between December 2006 and April 2009 to the University Hospital Basel with a suspicion of GCA were eligible for the study. DS of 2x11 arterial regions was performed in all study participants, and American College of Rheumatology criteria were applied to classify patients into GCA or non-GCA groups. RESULTS: GCA was diagnosed in 38 of the 72 participants (53%). A DS pattern suggestive of vessel wall inflammation was not observed in any of the patients in the non-GCA group but, in 21 of the 38 patients with GCA (55%), DS signs suggestive of vessel wall inflammation of > or =1 vessel region were detected. In 12 of the 38 patients with GCA (32%), DS signs of large vessel vasculitis (LVV) were found in > or =1 vessel region(s) of both upper and lower limb vessels. Follow-up DS was performed 6 months after the baseline examination in 9 of the 12 patients with LVV and showed the persistence of most findings despite normalised signs of systemic inflammation. CONCLUSION: DS detects changes in the vessel wall that appear to be specific for GCA; they can be present in upper and lower limb arteries of patients with GCA. Surprisingly, DS-detectable LVV and signs of systemic inflammation are largely dissociated.