Fig. 2.

Example of a venous sampling that distinguished between multiple positive images. FDG-PET imaging identified suspicious lesions in both the acetabulum (A) and the patella (B) that were suspicious for the FGF-23-secreting tumor. The results of the selective venous sampling measurements of FGF-23 (C) confirmed that the lesion in the acetabulum was the FGF-23-secreting tumor. The suspicious lesions are indicated by the arrows. This was confirmed by surgical removal and resolution of hypophosphatemia.