Vertebral arteries: a target for FDG-PET imaging in giant cell arteritis? Clinical, ultrasonographic and PET study in...

To demonstrate the capacity of FDG-PET to show active giant cell arteritis (GCA) of the extracerebral vertebral artery (VA) and to compare it with clinical, ultrasonographic (US) and biopsy findings.

Observational study of 46 consecutive patients with the diagnosis of active GCA and abnormal high FDG uptake in the aorta and other large arteries suggestive for GCA.

15 of the 46 GCA patients had abnormal high FDG uptake within the extending from the V0 to V3 segment in 13 and confined to single segments in 2 patients. In 2 patients high FDG uptake in one VA was the onIy PET abnormality. In 13 patients high FDG uptake was also found in other large arteries (carotid n = 10, subclavian/axillary artery n = 12, thoracic aorta n = 12). Abnormal PET was detectable in 5 patients despite glucocorticoid (GC) treatment. Nuchal and occipital pain and ischemic stroke or TIA in the posterior circulation (n = 3) were found in 10 patients with high VA FDG uptake. US detected halos of the V0-2 segments in 8/46 patients (5/15 VA PET positive and 3/31 VA PET negative patients). Biopsies were available in 10/15 VA PET positive patients with evidence of active GCA in 7 cases.

In patients with severe GCA and a high TVS the extracranial VA are a good target for PET imaging in active GCA with abnormal findings in 33% of patients with a positive PET. VA abnormalities can be an early and isolated finding in active GCA. PET is superior to US for the detection of active VA-GCA. A strong correlation between VA abnormalities and associated clinical abnormalities existed in 2/3 of patients. PET abnormalities of the VA could be detected in some cases after GC treatment has been started even at high doses.