Definitions and online reliability assessment of elementary ultrasound lesions in Takayasu arteritis: a study from the OMERACT Ultrasound Working Group.

25/01/2026

Seminars in arthritis and rheumatism

Authors: Alessandro Tomelleri, Simon J Reider, Christian Dejaco, Wolfgang A Schmidt, Cristina Ponte, Alojzija Hocevar, Ana Filipa Águeda, Fatma Alibaz-Oner, Simone Appenzeller, Markus Aschwanden, Hans Bastian, Philipp Bosch, Dario Camellino, Vincent Casteleyn, Stavros Chrysidis, Thomas Daikeler, Eugenio De Miguel, Andreas P Diamantopoulos, Georgios Filippou, Ruchika Goel, Petra Hanova, Wolfgang Hartung, Kei Ikeda, Nevsun Inanc, Sandrine Jousse-Joulin, Aaron Juche, Rositsa Karalilova, Kresten Krarup Keller, Søren Geill Kjær, Minna J Kohler, Matthew J Koster, Pierluigi Macchioni, Sarah L Mackie, Marcin Milchert, Durga Prasanna Misra, Juan Molina-Collada, Sara Monti, Daiki Nakagomi, Esperanza Naredo, Berit Dalsgaard Nielsen, Michihiro Ogasawara, Johannes Roth, Valentin S Schäfer, Luca Seitz, Pascal Seitz, Russka Shumnalieva, Lene Terslev, Kornelis S M van der Geest, Florentin Ananu Vreju, Maria-Antonietta D'Agostino, Helen I Keen, Peter Mandl, Carlos Pineda, Christina Duftner, Milena Bond

OBJECTIVES: Reliable tools for monitoring disease activity in Takayasu arteritis (TAK) are lacking, and ultrasonography (US) may represent a valuable option. This study aimed to: 1) develop consensus-based definitions for key US lesions in TAK; 2) identify the relevant arterial segments to include in an US-based score; 3) assess inter- and intra-rater reliability of the definitions in a web-based image analysis and scoring exercise.

METHODS: A Delphi survey was conducted among members of the OMERACT Ultrasound Working Group to agree upon the definitions of key elementary US lesions and arterial segments to be included. A subsequent web-based reliability exercise included US images from TAK patients and healthy controls depicting the consensual lesions. Experts scored each image in two separate rounds. Inter-rater and intra-rater reliability were assessed using Fleiss' and Cohen's kappa (κ), respectively.

RESULTS: Three Delphi rounds were completed with 47, 46, and 43 experts respectively. Consensus was reached on three lesions ('macaroni sign', stenosis, occlusion) and seven arterial segments (bilateral common carotid, subclavian, axillary arteries, abdominal aorta). Forty-five experts completed the reliability exercise. Inter-rater reliability was moderate to good (κ = 0.47-0.64), with the highest agreement for the 'macaroni sign' in the carotid artery (κ = 0.73). Intra-rater reliability was good (κ = 0.72-0.79), with lower agreement for stenosis and occlusion in the abdominal aorta.

CONCLUSIONS: This OMERACT initiative established consensus-based definitions for US lesions in TAK and identified key relevant arterial segments, providing a reliable basis for the development of a standardized US composite score.

PMID: 41702323