Abstract: Objective The aim of this study was to summarize the contrast-enhanced ultrasonography (CEUS) imaging manifestation of liver abscess (LA). Methods 120 patients with LA were admitted to our hospital from April 2016 through April 2019, and all patients underwent routine two-dimensional ultrasonography and CEUS before abscess puncture drainage. The consistency of CEUS and routine two-dimensional ultrasound in diagnosis of LA was compared. Results Out of the120 patients, 22 cases were at inflammatory stage of abscess, 42 cases wereat early abscess formation and 56 cases were at abscess formation; 107 cases (89.2%) were detected by routine two-dimensional ultrasonography, and among them, the abscesses at inflammatory and at early stage of abscess formation showed irregular or regular lesions with unclear or clear boundary, without liquid dark area in the lesions and having blood flow signals, and those at abscess formation demonstrated the irregular or regular lesions with unclear orclear borders and fluid dark areas without blood flow signals; 117 LA cases (95.0%) were detected by CEUS, and among them, the abscesses at inflammatory stage of abscess and at early stage of abscess formation presented high enhancement at the arterial phase, low enhancement at portal venous and delayed phase with the display range larger than that by conventional ultrasound, and those at abscess formation manifested high enhancement at arterial phase, low enhancement at portal vein and delayed phase, and their display range significantly larger than that by conventional ultrasound; the sensitivity, specificity, positive predictive value, negative predictive value and Kappa value by CEUS were 95.0%, 76.9%, 89.7%, 33.3% and 0.88, respectively. Conclusion The LA CEUS imaging manifestations have their own characteristics, and the sensitivity, specificity and accuracy of diagnosis by it are high, and we recommend its application when the diagnosis is obscure.

Key words: Liver abscess, Contrast-enhanced ultrasonography, Two-dimensional ultrasonography, Diagnosis