Giant cell arteritis and polymyalgia rheumatica: usefulness of vascular magnetic resonance imaging studies in the diagnosis of aortitis.

OBJECTIVES One of the unresolved challenges posed in giant cell (temporal) arteritis (GCA) is the detection and monitoring of large-artery complications, particularly aortitis. Recent investigations support vascular magnetic resonance imaging (MRI) studies in this issue. We report our preliminary experience with this imaging technique in the study of the aorta and its proximal branches in patients with GCA and/or polymyalgia rheumatica (PMR). METHODS Between 2000 and 2003, six patients with GCA and/or PMR seen in our department were diagnosed with aortitis using vascular MRI studies. In all cases, the study was performed according to a specifically designed protocol that included MRI and MR angiography (MRA). RESULTS MRI was a hepful non-invasive method for diagnosis of aortitis in all cases, providing accurate information about its extent. In particular, MRI had a higher ability to detect earlier stages of vasculitis disclosing subclinical aortitis in five of the six patients. The main signs of early vascular inflammation observed were vessel wall thickness and oedema (six cases) and increased mural enhancement on postcontrast T1-weighted images (four cases). MRA disclosed lumen changes (stenosis) in two patients. On follow-up studies, whereas vascular stenosis and vessel wall thickness remained invariable, vascular wall oedema and contrast enhancement improved significantly when disease activity decreased. CONCLUSION MRI may be a useful technique for diagnosing patients with occult major artery involvement in GCA, whether presenting with classic symptoms of temporal arteritis or PMR. Its utility for monitoring the course of the disease and response to treatment requires further confirmation.