Settlement of fluorine-18 fluorodeoxyglucose (18F-FDG) in the bladder is often noted in whole-body PET/CT images, but this phenomenon never received any careful attention and the mechanism was unclear.
These two patients, including one with T1 pathological fracture and the other with widespread bone and lymph node metastases from an unknown primary tumor, underwent the PET/CT examination. They both had urinary tract infection and a distended bladder during scanning. The interesting layering of FDG in the urinary bladder was shown in both patients. Presence of this phenomenon demands careful evaluation of the urine by the clinician, and the mechanism is hypothesized to be because of slow 18F-FDG excretion in patients with a distended urinary bladder resulting in delayed mixing with urine. In addition, urinary tract infection may be a potential cause. The clinician should pay more attention to interpreting the imaging of bladder with interesting layering.
Shen G, Zhang W, Jia Z, Deng H. Are you the author?
West China Hospital of Sichuan University.
Reference: J Nucl Med Technol. 2014 Dec 23. pii: jnmt.114.148031.