In this study, using an experiment, in certified an error between each system of SUV (standardized uptake value) that is one of the main analyses to diagnose a tumor in PET/CT, so, it would assure reliability and help to diagnose any lesions accurately. That is, a detailed analysis progressed. as all images reconstructed every setting time, then, clinical reliability between each system was expressed numerically at MBq/mL and SUV. Therefore, this study is considered that flexibility of follow-up using diverse system was insured, and it helps to offer accurate and beneficial information for diagnosis of various fields.