TY - JOUR T1 - Definitions and reliability assessment of elementary ultrasound lesions in giant cell arteritis: a study from the OMERACT Large Vessel Vasculitis Ultrasound Working Group JF - RMD Open JO - RMD Open DO - 10.1136/rmdopen-2017-000598 VL - 4 IS - 1 SP - e000598 AU - Stavros Chrysidis AU - Christina Duftner AU - Christian Dejaco AU - Valentin S Schäfer AU - Sofia Ramiro AU - Greta Carrara AU - Carlo Alberto Scirè AU - Alojzija Hocevar AU - Andreas P Diamantopoulos AU - Annamaria Iagnocco AU - Chetan Mukhtyar AU - Cristina Ponte AU - Esperanza Naredo AU - Eugenio De Miguel AU - George A Bruyn AU - Kenneth J Warrington AU - Lene Terslev AU - Marcin Milchert AU - Maria Antonietta D’Agostino AU - Mattew J Koster AU - Naina Rastalsky AU - Petra Hanova AU - Pierluigi Macchioni AU - Tanaz A Kermani AU - Tove Lorenzen AU - Uffe Møller Døhn AU - Ulrich Fredberg AU - Wolfgang Hartung AU - Bhaskar Dasgupta AU - Wolfgang A Schmidt Y1 - 2018/05/01 UR - http://rmdopen.bmj.com/content/4/1/e000598.abstract N2 - Objectives To define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise.Methods Potential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise.Results Twenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The ‘halo’ and ‘compression’ signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the ‘halo’ sign and the ‘compression’ sign was excellent with inter-rater agreements of 91–99% and mean kappa values of 0.83–0.98 for both inter-rater and intra-rater reliabilities of all 25 experts.Conclusions The ‘halo’ and the ‘compression’ signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent. ER -