Figure 1.

Display of a 68-year-old male with Bence–Jones kappa multiple myeloma Revised International Staging System (R-ISS) II. In ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT), focal lesions (FL) located on the right thyroid cartilage and sacral bone were identified. Nevertheless, the focal uptake on the lower cervical region and left clavicle corresponded to a lymph node and a fracture, respectively, and were thus considered unspecific findings. Please note that diffuse uptake in ¹⁸F-FDG PET/CT was homogeneous and below the liver cut-off. Conversely, a combined infiltration pattern with bone marrow (BM) infiltration and more than 10 FL was present in ¹¹C-MET PET/CT. Importantly, they did not demonstrate a correlation in ¹⁸F-FDG PET/CT (fusion images).