1 Vasculitis Research Unit, Department of Systemic Autoimmune Diseases, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Villarroel 170, Barcelona, 08036, Spain.
2 Center for Diagnostic Imaging, Hospitall Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Villarroel 170, Barcelona, 08036, Spain.
3 Department of Nuclear Medicine, University of Barcelona, Hospital Clínic, Barcelona, Spain.