Giant cell arteritis is a vasculitis, i.e. inflammation of the artery walls, which generally affects people over the age of 50. Diagnosis can be long and difficult, as the clinical signs are not specific (headache, pain in the jaw, scalp, shoulders and/or pelvis, abdominal pain, weight loss, etc.), but it must be made quickly, given the risk of complications. The reference method for diagnosis was initially based on clinical suspicion and analysis of a piece of temporal artery (biopsy) performed in the operating theatre under local anaesthetic. Since the mid-1990s, improvements in ultrasound techniques have made it possible to identify a sign, known as a halo, on the temporal arteries that is typical of patients with Giant Cell Arteritis. A prospective multicenter study published in 2024 demonstrated that, in patients with a clinical suspicion of Giant Cell Arteritis, if a halo was found on both temporal arteries by ultrasound, there was no need for a biopsy. This study is at the origin of a change in practices in the diagnosis and care of patients suffering from this disabling disease. To facilitate early diagnosis, a fast-track pathway has been set up. The aim is to make a rapid diagnosis, thereby reducing the risk of after-effects, shortening the length of hospital stays, considering outpatient treatment and limiting the number of biopsies. The investigators propose to evaluate the performance of this fast-track pathway.