All diseases occur as some biochemical changes that develop abnormally in the initial stage. PET is a very important diagnostic tool in the early stages of diseases, where a structural disorder has not yet occurred, but abnormal biochemical activity begins. PET / CT is a high-tech imaging system with a single bed, which combines Positron Emission Tomography (PET) and Computed Tomography (CT). The new systems allowed the use of less PET imaging agents and lower CT doses, minimizing the received radiation dose. 

Today, PET / CT is frequently used in early diagnosis, staging, restaging of cancer cases, predicting the future about the disease, monitoring and evaluating the response to treatment, determining the appropriate biopsy site, and radiotherapy planning. As PET/CT imaging allows simultaneous screening of the whole body, it enables determining whether the disease has spread to other organs or not. It can also be used in heart diseases, brain and nerve diseases, and psychiatric diseases. PET/CT also provides answers to questions as to whether an active disease is still present after the treatment or not; and how efficient the treatment has been.