PET-CT is suggestive of all kinds of tumors, because PET-CT determines whether there is any abnormality through the degree of absorption of sugar substances by various tissues in the body. If sugar metabolism increases abnormally, it can be considered as tumor, but the diagnosis still needs to be confirmed by obtaining pathology.PET-CT has great significance to the staging of tumors, so PET-CT can be done to determine the staging of tumors after discovery, and if there are conditions, it can be used to monitor whether the tumors recur after chemotherapy.PET-CT has more significance in the diagnosis and review of lymphomas because lymphomas have a wide range of invasion, and PET-CT can monitor whether the tumors recur at a glance. PET-CT can detect all metastatic lesions at a glance.