[Imaging diagnostics in large vessel vasculitis]

Imaging procedures have become an important diagnostic tool in vasculitis. In large vessel vasculitides, such as giant-cell arteritis (GCA) and Takayasu arteritis, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can depict specific abnormalities of the arterial wall. A clinically suspected diagnosis can be confirmed by imaging if performed by a trained specialist using appropriate equipment, without histological investigations. Ultrasound, MRI and CT show a homogeneous, concentric thickening of the arterial wall and PET can detect increased glucose metabolism of the arterial wall. Ultrasound is the method of choice, especially in predominantly cranial GCA. Imaging should be performed before or within the first few days of glucocorticoid treatment as the PET findings of all arteries as well as ultrasound and MRI findings in temporal arteries normalize quickly with treatment. A planned imaging examination must not delay initiation of glucocorticoid treatment.