Ultrasound of temporal and axillary arteries is recommended as first-line imaging in all patients with suspected giant cell arteritis (GCA), new EULAR guidelines state.
The recommendation is an update to previous 2018 guidelines that distinguished between cranial and extracranial phenotypes and acknowledges that GCA represents a single disease spectrum with phenotypes that overlap.
The new guidance [link here] was prompted by recent imaging recommendations from the American College of Rheumatology, which expressed a preference for temporal artery biopsy (TAB) over ultrasound and MRI of cranial arteries in the diagnosis of GCA, in contrast to previous EULAR and British Society for Rheumatology advice.
“These and other developments have prompted us to re-evaluate and update the original EULAR recommendations, particularly addressing uncertainties about the choice of the imaging technique for diagnosis and assessment of patients with GCA and Takayasu arteritis (TAK),” the authors wrote in the Annals of the Rheumatic Diseases.
Developed by a task force of 24 physicians, health professionals and patients from 14 countries, the recommendations also advise that FDG-PET or MRI can be used as an alternative to ultrasound to examine cranial and extracranial arteries in suspected GCA.
While MRI was the preferred imaging modality in patients with suspected TAK, FDG- PET, and CT were alternatives. Ultrasound was also an option but was of ‘limited value’ in assessing the thoracic aorta.
The task force noted that although imaging was not routinely recommended for follow-up, ultrasound, FDG- PET or MRI may be used for assessing vessel abnormalities in LVV patients with suspected relapse, particularly when laboratory markers of inflammation were unreliable.
Furthermore, MR- angiography, CT- angiography, or ultrasound of extracranial vessels could be used for long-term monitoring of structural damage in patients with GCA or TAK.
“The key modification of this recommendation is the incorporation of the concept that vascular damage mainly occurs at sites of preceding vascular inflammation,” the authors wrote.
They concluded that the update had led to some important changes from the original recommendations, particularly concerning the investigation of axillary arteries by ultrasound in patients with suspected GCA, the use of FDG- PET for the diagnosis of GCA and the use of imaging for the assessment of patients with GCA or TAK during follow- up.
“It is not the intention of the EULAR imaging recommendations to dismiss the role of TAB in GCA; however, when imaging is rapidly available and reveals clear signs that are in concordance with the clinical picture, the added value of performing a TAB is uncertain,” they added.