Role of ultrasonography in the diagnosis of temporal arteritis

Background: Temporal artery (TA) biopsy is the current standard for diagnosing temporal arteritis, but has limited sensitivity. Colour duplex ultrasonography is a newer, non-invasive method of diagnosing temporal arteritis. Methods: A systematic review was performed of trials comparing TA biopsy with duplex ultrasonography. Duplex results (halo sign, stenosis or vessel occlusion) were compared with either TA biospy findings or the American College of Rheumatology research criteria for diagnosing temporal arteritis. Trials were identified from MEDLINE, Embase and the Cochrane Library trials register. The performance of duplex ultrasonography was assessed with weighted independent sensitivity and specificity values, and summary receiver operating characteristic curve analysis. Results: There were 17 eligible studies containing 998 patients. When the halo sign on duplex imaging was compared with TA biopsy, the sensitivity was 75 (95 per cent confidence interval 67 to 82) per cent and the specificity was 83 (78 to 88) per cent. There was no heterogeneity across the eligible studies. Conclusion: Duplex ultrasonography was relatively accurate for diagnosing temporal arteritis. It should become the first-line investigation, with biopsy reserved for patients with a negative scan.