Figure 6. Comparison of tumour-to-background ratio (T/B ratio) of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and FDG dual-head positron coincidence determination gamma camera detection (PCD). T/B ratio of FDG PCD (3.5±3.3) is significantly lower than obtained by FDG PET (8.4±7.1, p<0.001).