Background Giant cell arteritis (GCA) is the most frequent vasculitis in adulthood. The delay in diagnosis sets back treatment and can lead to serious consequences. Diagnosis is complex, and is followed by the classification criteria according to the American College of Rheumatology (ACR). The is an increasing interest on the utility of temporal artery ultrasound (TAUS) as a tool to evaluate inflammation on the vessel wall.

Objectives to evaluate the utility of TAUS in GCA.

Methods During 2016, 120 TAUS were carried out in 60 patients with clinical suspicion for GCA. The TAUS was carried to completion by rheumatologist with experience. The symptoms that lead to a TAUS was either one or more of these clinical scenarios: 1) cranial symptoms (recent onset headache, mandibular claudication, visual disturbances) 2) polymyalgic syndrome 3) toxic o febril unspecific syndrome 4) vertebrobasilary (VB) stroke. Demographic and laboratory data were collected, and a follow-up was done to learn the final diagnosis. As for TAUS, the “halo” sign was considered positive if an anechoic image surrounded the vessel was present, and measured >0,30 mm in both, longitudinal and transverse cuts. Other more unspecific signs as stenosis or occlusion were also registered. A temporal artery biopsy was performed whenever the physicians considered necessary, based on clinical criteria, every case in no more than 30 days.

Results Fifty-two percent were women, mean age 76±7.8 years old. Mean laboratory parameters: eritrosedimentation rate 85±41.9 mm/h, C-reactive protein 77±80 mg/L, Haemoglobin 11.4±2.2 g/L, white blood count 10,228±3,520, platelet count 310,603±123,918. The symptoms that motivated requesting the TAUS were: cranial symptoms (62.2%), toxic, unspecific, febrile syndrome (44%), polymyalgic syndrome (30%), VB stroke (5%). A temporal artery biopsy was carried out in 45% of patients (N=27); it was positive in 40.7%, negative in 40.7% and unspecific (given it reported an inflammatory histologic pattern, but without the characteristic giant cells) in 18.5%. From all 60 patients in whom a TAUS was performed, 36% were diagnosed with GCA, based on ACR criteria.

The sensibility and specificity for TAUS was 80% and 94% respectively, with a posivite predictive value of 88.9% and a negative predictive value of 89.2%

Conclusions TAUS is a useful, non-invasive, fast, accessible tool for evaluating temporal arteries with a great diagnostic valu

Disclosure of Interest None declared