FIGURE 1.  A 69-y-old man with papillary bladder cancer. (A) Coronal prediuretic ¹⁸F-FDG PET image shows complete masking of primary tumor by urinary activity. (B) Transaxial postdiuretic ¹⁸F-FDG PET image after 2 voidings of urinary bladder shows equivocal finding. (C and D) Transaxial postdiuretic ¹⁸F-FDG PET after 3 voidings (C) and correlative MRI (D) reveal T1 tumor in left lateral wall of bladder (arrows).