Black, R.Roach, D.Rischmueller, M.Lester, S.Hill, C.2014-10-012014-10-012013International Journal of Rheumatic Diseases, 2013; 16(3):352-3571756-18411756-185Xhttp://hdl.handle.net/2440/85717Article first published online: 8 JUN 2013Aim: The exact diagnostic role of temporal artery ultrasound (TAU) remains unclear. The aim of this study was to determine the sensitivity and specificity of a positive halo sign in patients undergoing TAU in a clinical setting, and to perform a review of existing evidence. Method: Patients who had undergone TAU at a single centre in Australia were included in the study. The presence or absence of a halo sign and whether it was unilateral or bilateral was determined retrospectively from radiology reports. Pathology results were used to determine which patients underwent a temporal artery biopsy and if the biopsy was positive or negative. A case note review was performed to determine presenting clinical features and if a clinical diagnosis of giant cell arteritis was made. The sensitivity, specificity and likelihood ratios of TAU compared to both biopsy and clinical diagnosis were calculated. Results: Fifty patients were identified as having had a TAU (28% male, mean age 69). When compared to biopsy-proven cases, the sensitivity of a halo sign was 40%, specificity 81%, positive likelihood ratio 2.1 and negative likelihood ratio 0.7. When compared to clinical diagnosis, the sensitivity was 42%, specificity 94%, positive likelihood ratio 7.1 and negative likelihood 0.6. Conclusions: Sensitivity and specificity results were comparable to the literature. A halo sign may preclude the need for biopsy in cases of high clinical suspicion and contraindications to surgery. Biopsy remains necessary in most cases, irrespective of whether a halo sign is present.en© 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty LtdClinical practice; diagnosis; giant cell arteritis; temporal artery ultrasoundJournal article002013711610.1111/1756-185X.121080003345210000182-s2.0-848960594782-s2.0-8487870360615066Black, R. [0000-0001-6600-7430]Roach, D. [0000-0002-7242-4561]Rischmueller, M. [0000-0001-5057-3286]Hill, C. [0000-0001-8289-4922]