Each patient will usually receive a single IV injection of 18F-FDG. Imaging will be conducted 30 to 60 minutes after an average injection of 200 - 300 MBq of 18F-FDG in hydrated, fasted patients. Images will be collected for 40 to 60 minutes in 5 - 7 body positions (total counts 5 to 15 million). For the Phase I/II study, images will be interpreted by a single experienced Nuclear Medicine physician with regard to normal physiological uptake of 18F-FDG. For the Phase III study, images will be interpreted independently by two experienced Nuclear Medicine physicians with regard to normal physiological uptake of 18F-FDG. The location and intensity of abnormal 18F-FDG uptake will be noted and correlated with clinical findings, surgical or biopsy results or with conventional imaging techniques, as available. The image review will be supplemented with access to clinical and conventional imaging data in the Phase I/II study. In the Phase III study all images will be reviewed independently by one physician blinded to all clinical data except the primary diagnosis and by one physician with access to all relevant clinical information. In the extended Phase III protocol the images will be interpreted by a single physician with access to relevant clinical information