1. Rheumatology Unit, University Clinic AOU Cagliari, Monserrato
2. Department of Medical Sciences and Public Health, University of Cagliari
3. Department of Radiology, University Clinic AOU Cagliari, Monserrato, Cagliari
4. Academic Rheumatology Centre, Dipartimento di Scienze Cliniche e Biologiche, Università degli Studi di Torino, MFRU, Turin, Italy