Our hospital introduced the province’s first gamma camera in 1981 and started nuclear medicine. Now we have a PET-CT scanner and two gamma-cameras (SPECT), which are the newest devices in Korea. In particular, the PET-CT scanner, a molecular imaging device, is a very important in the early detection of cancer and the assessment of therapeutic effects. Positron emission tomography (PET) is to scan the human body for the biochemical disorders of metabolism, and computed tomography (CT) is to scan for structural problems. A PET-CT scanner is a combination of the two. Almost every disease and cancer shows a biochemical change of metabolism before a structural change occurs. PET can visualize such a biochemical change, and therefore can early detect cancer and find even subtle changes.