Hypodense shadow in S8 segment of liver consider lesions such as liver abscess, parasites and various benign and malignant tumors. 1. Liver abscess: according to different pathogenic microorganisms, it is divided into bacterial liver abscess, amoebic liver abscess, fungal liver abscess, tuberculosis liver abscess, etc. Bacterial liver abscess is more common. Bacterial liver abscess is characterized by round or round-like low-density foci in the liver parenchyma, with a pus cavity in the center and uniform or uneven density on CT scan. 2. Liver parasitic diseases: e.g. hepatic echinococcosis, its CT scanning manifestation is different sizes, single or multiple, round or round-like, watery cystic foci (low-density foci), with clear borders and smooth edges; its characteristic manifestation is the appearance of cysts within the mother cyst. 3. benign liver tumor: for example, hepatic cavernous hemangioma, its CT scan manifests as a round or round-like low-density mass with clear boundary in liver parenchyma. 4. Malignant tumors of liver: such as hepatocellular carcinoma, its CT scan shows that most of the masses are hypointense, and a few of them are isointense or hyperintense. Please consult the doctor in time and combine with other examinations if necessary. Patients with abnormalities in imaging should consult a doctor in time to avoid delaying the condition.