PET is a diagnostic imaging method that evaluates metabolic, functional and pathophysiological parameters by mapping the biodistribution of radiopharmaceutical agents administered to the patient. One of the main radiopharmaceuticals that have been used in PET technology is FDG-18F, the deoxyglucose molecule labeled with fluorine-18. Its beahaviour is similar to that of glucose, enabling a competition between the two by a facilitated transport mechanism. Diabetic patients with high glucose need to use insulin, as there may be low uptake of FDG-18F in the organ of interest. This study is a bibliographical review, based on specific scientific literature, using the Scielo and PubMed repositories as search engines. We observed the impact that hyperglycemia can cause during a PET-CT scan. It may be noted that elevated glucose during PET-CT examination causes image problems. It is extremely important the constant trainment of the entire team, as well as the execution of a serious and clear anamnesis to know if the patient's preparation was done correctly.
Keywords: PET-CT, nuclear medicine, GLUT receptors, insulin, FDG, hyperglycemia.