title: Interesting Layering of Excreted 18F-FDG in the Urinary Bladder in Patients with Urinary Tract Infection and Distended Bladder.
abstract: Settling of (18)F-FDG in the bladder is often noted on whole-body PET/CT images, but this phenomenon has never received any careful attention and the mechanism has been unclear. The 2 patients described in this report, one with a T1 pathologic fracture and another with widespread bone and lymph node metastases from an unknown primary tumor, underwent PET/CT. Both had urinary tract infection and a distended bladder during scanning. The interesting layering of (18)F-FDG in the urinary bladder was observed in both patients. The presence of this phenomenon demands careful evaluation of the urine by the clinician, and the mechanism is hypothesized to be slow (18)F-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. Images showing this interesting layering should be interpreted with care.
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Shen
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China zhiyunjia@hotmail.com.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Jia
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Houfu
authors.initials: H
authors.lastname: Deng
mesh_terms: D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000378:metabolism*; D001745:Urinary Bladder Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism*; D014552:Urinary Tract Infections / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG layering; positron emission tomography/computed tomography; urinary bladder