The most common etiology of multiple hypodense foci in the liver is the possibility of metastatic foci due to tumor metastasis. In this case, it is recommended to continue to check the enhanced CT to see the nature of the low-density swelling in the liver. If necessary, PET-CT needs to be checked to see the location of the primary tumor. Some patients with multiple hepatic cysts can also present with multiple hypodense foci in the liver, a condition that would typically suggest negative results on PET-CT. If the patient has multiple hypodense foci in the liver, which is proved to be metastatic foci by PET-CT, the site of the primary foci needs to be further identified, such as whether it originates from the colorectum and whether it originates from the stomach or lung, and the next step of chemotherapy or radiotherapy can be considered after identifying the tumor in the primary site. At the same time, patients should pay attention to rest and maintain their immunity, because the next step of treatment may cause the patient’s health condition to deteriorate and immunity to decrease.