Temporal artery biopsy is no longer the gold standard test for the diagnosis of giant cell arteritis (GCA), with ultrasound now a reliable and less invasive option for many patients, according to new EULAR recommendations.

Advances in ultrasound technology mean that a positive imaging test can be relied on for confirming a diagnosis of GCA in patients for whom there is a high degree of clinical suspicion, the new guidelines published in Annals of the Rheumatic Diseases state.

Imaging can also be used to exclude GCA in patients for whom there is low suspicion of disease.

In 12 evidence-based recommendations on the use of imaging in large vessel vasculitis, EULAR representatives from 10 countries said ultrasound of the temporal arteries should be conducted before starting steroid treatment or at least within a week, with a non-compressible halo sign being suggestive of GCA.

High resolution MRI of cranial arteries is an alternative if ultrasound is not available.

The guideline authors say a diagnosis of GCA may be made on the basis of imaging, along with other suggestive features such as such as a high ESR and CRP levels and symptoms.

However, this did not mean that biopsy was no longer recommended. It may still have a role depending whether the diagnosis is in question after imaging, and its use should be determined on a case by case basis based on clinical probability.

“The present [recommendations] not intended to discredit the role of biopsy … nevertheless, the taskforce felt that temporal artery biopsy may be dispensable in cases where GCA is confirmed or excluded based on clinical, laboratory and imaging results,” they said.

CT and PET imaging are alternatives to ultrasound and MRI but are not recommended for assessment of inflammation of cranial arteries.

The guidelines note that about one in five people with polymyalgia rheumatica may develop GCA, for which ultrasound imaging has a 77% sensitivity and a 96% specificity.

The new guidelines supersede previous 2009 EULAR advice on the management of large vessel vasculitis, which stated that temporal artery biopsy was the only reliable diagnostic test.