Ponte C, Serafim AS, Monti S, et al. - The present study was undertaken to compare the ultrasound characteristics with clinical features, final diagnosis and outcome; and to assess the halo size following glucocorticoid treatment in patients with newly diagnosed giant cell arteritis (GCA). An international cohort was conducted to include patients with suspected GCA, had an ultrasound of temporal (TA) and axillary arteries performed within 7 days of commencing glucocorticoids. Researchers matched variations in clinical features at disease presentation, after 2 weeks and after 6 months, according to the presence or absence of halo sign. Pearson’s correlation coefficient (r) and Analysis of Variance were applied to conduct a cross-sectional analysis of the differences in halo thickness. This study included a sum of 345 patients with 6 months follow-up data; 226 (65.5%) had a diagnosis of GCA. This study's findings demonstrate that TA halo is correlated with the presence of ischaemic features and its size decreases following glucocorticoid treatment in newly diagnosed GCA, supporting its early use as a marker of disease activity, in addition to its diagnostic role.