Abstract

Over the past years imaging techniques such as Color-Coded Duplex Sonongraphy (CCDS), Magnetic Resonance Imaging (MRI), Magnetic Resonance Angiography (MRA) and Positron Emission Computed Tomography (PET CT) have greatly improved their diagnostic accuracy for the diagnosis of large vessel vasculitis. This presentation summarises the specific advantages and limitations of CCDS, MRI/MRA and PET CT.

CCDS is the diagnostic procedure of first choice in the hands of an experienced observer. CCDS is readily available and may display the so called “halo-sign” of an inflamed vessel wall of the superficial temporal, axillary, carotid, vertebral and subclavian artery.

PET CT is thougt to be the most sensitive imaging modality, especially for the assessment of extracranial large artery involvement. PET CT is not as widely available, rather costly and applies radiation.

MRI and MRA are noninvasive imaging modalities that display mural inflammatory changes of intracranial, extracranial and large artery involvement. MRI and MRA do not use radiation. In relation to costs and availability MRI and MRA lie somewhere between CCDS and PET CT. Image acquisition in PET CT and MRI/MRA is standardized and largely independent of the operator.

Mural inflammatory signs depicted by CCDS, PET CT and MRI/MRA vanish over time under sufficient therapy. However, interpretation of persistant mural changes and imaging of relapsing disease is not yet fully understood.