Liver abscess is categorized into bacterial and amoebic, with ultrasound showing hypoechoic or anechoic areas, X-ray showing diaphragmatic elevation, and CT showing hypodense areas. 1. Bacterial liver abscess (1) Ultrasound: Early lesions are low to moderate echogenic, and the boundary with surrounding tissues is unclear. With the progression of the disease, echogenic liquefied area can be seen under ultrasound, and the echogenicity of the abscess wall is enhanced. (2) X-ray: right lobe liver abscess can be seen with elevated right diaphragm, restricted movement, enlarged or limited elevation of liver shadow, which may be accompanied by reactive pleural cavity effusion. X-ray barium examination of left lobe liver abscess shows compression and migration of the lesser curvature of the stomach. (3) CT: Plain CT shows hypodense and inhomogeneous changes, with diverse morphology, single or multiple, single or multiple compartments, round or oval, and clear borders. Those who have formed abscesses have thicker walls, and there may be gas shadows in the abscess cavity. Enhanced CT is not uniformly enhanced before the formation of abscess cavity, and after the formation of abscess cavity, the inner side of its wall is smooth and enhanced, and the outer side of the wall is blurred. 2. Amebic liver abscess (1) Ultrasound: It shows the appearance of round or ovoid hyperechoic area with clear boundary or anechoic area in the liver. (2) X-ray: when it occurs in the right lobe of the liver, it often elevates the right diaphragm and compresses the right lung base, resulting in flaky shadows in the lower part of the right lung, discoidal lung atelectasis, and pleural effusion on the right side, etc. When it occurs on the left side, it may appear as an amoebic liver abscess. When it occurs on the left side, left pleural effusion and pericardial effusion may occur. (3) CT: It shows a uniform round or ovoid low-density area with poorly defined edges. After enhancement, the abscess wall is ring-shaped enhancement, and there may be gas within it. Patients with liver abscess should go to the hospital in time and receive standardized treatment under the guidance of doctors.