Doppler ultrasonography in the diagnosis of giant cell arteritis.

Ultrasonography of the temporal arteries detects characteristic signs of vasculitis with a high sensitivity and specificity: a hypoechoic halo due to an oedema of the artery wall and stenoses. The use of modern scanners with high resolution is essential. A halo has to be displayed in two planes. It is always circumferential. The colour intensity must not be too strong, otherwise the colour may cover the halo. A hypoechoic halo is also seen in large vessel giant cell arteritis at the axillary and brachial arteries and at the temporal arteries in polyarteritis nodosa.