Pathologies of the lower abdomen and pelvis: PET/CT reduces interpretation errors due to urinary contamination. 
The aim of this study was to assess the frequency of indeterminate (18)F-fluorodeoxyglucose (FDG) accumulations on positron emission tomography (PET) and PET/computed tomography (CT) images in patients with pelvic pathologies.  We retrospectively evaluated 536 focal FDG accumulations of 166 PET/CT examinations.  A consensus reading of PET/CT images, clinical data, and other imaging tests was the standard of reference to assess sensitivities and specificities of PET and PET/CT.  Frequencies of indeterminate findings and intraobserver agreement were evaluated.  PET/CT improves the anatomic delineation and the correct assignment of physiologic and pathologic uptake.