Diagnosis is based on the demonstration of vascular lesions in large and middle-sized vessels on angiography, CT scan, magnetic resonance angiography or FDG PET. Seeing abnormal diffuse arterial wall thickening, the 'macaroni sign', with ultrasound is highly suggestive of the condition. FDG PET can help in diagnosis of active inflammation not just in patients with active<unk> kayasu arteritis prior to treatment but also in addition in relapsing patients receiving immunosuppressive agents. Contrast angiography has been the gold standard. The earliest detectable lesion is a local narrowing or irregularity of the lumen. This may develop into stenosis and occlusion. The characteristic finding is the presence of "skip lesions," where stenosis or aneurysms alternate with normal vessels. Angiography provides information on vessel anatomy and patency but does not provide information on the degree of inflammation in the wall. The age at onset helps to differentiate<unk>  from other types of large vessel vasculitis. For example,<unk>  has an age of onset of 60 years.<unk> kayasu arteritis is not associated with ANCA, rheumatoid factor, ANA, and anticardiolipin antibodies.
Takayasu's arteritis
Giant cell arteritis
Monckeberg's arteriosclerosis
Charcot–Bouchard aneurysm
Lupus vasculitis
Syphilitic aortitis
Arterial tortuosity syndrome
Polyarteritis nodosa