Pneumonia can cause increased PET-CT values. PET-CT utilizes positron nuclide labeling of glucose and other human metabolites as a contrast agent to reflect metabolic changes in the lesion through its uptake of the contrast agent. Pneumonia, because it is a local inflammatory reaction, vasodilatation and congestion, blood flow is accelerated, the local blood increases, catabolism is also enhanced, this tissue metabolism increases, the uptake of the contrast agent glucose will also increase, so it will also cause an increase in the value of PET-CT, in the control of inflammation the metabolism will decline, the value of PET-CT will decline accordingly. There is a difference between increased PET-CT values due to inflammation and increased tumors, with a high standardized uptake value of SUV representing a high likelihood of a tumor and a low to medium SUV representing a higher likelihood of inflammation. If you find an increase in PET-CT metabolism, it is recommended that you consult a doctor at the department of respiratory medicine or the department of oncology in your hospital to further clarify the diagnosis.