Images of FDG-PET obtained under TCZ therapy. (a) Whole-body 18F-FDG-PET/CT was performed before (a) at three (b) and six months (c) after the initiation of TCZ therapy. The FDG uptake in the affected joints had decreased. TCZ: tocilizumab. The contrasts of the PET images were adjusted on the basis of the liver density.