To explore the application value of contrast-enhanced ultrasound in the detection and qualitative diagnosis of focal liver lesions in the background of fatty liver.

From January 2018 to July 2020, 108 patients with mild or moderate fatty liver disease (153 lesions) who underwent contrast-enhanced ultrasound examinations at Ruijin Hospital and Wuxi Branch of Ruijin Hospital were retrospectively analyzed. Some of patients undertook the examination using high-frame-rate contrast-enhanced ultrasound mode. All the lesions were confirmed by pathology or by enhanced CT or MRI examination with follow-up. The accuracy, sensitivity, and specificity of conventional ultrasound and contrast-enhanced ultrasound in the detection and diagnosis of hepatic lesions were calculated, and χ² test was used to compare their accuracy in the differential diagnosis of benign and malignant lesions.

A total of 60 benign lesions and 93 malignant tumors were included in the study. The results showed that CEUS can improve the detection rate of focal liver lesions, especially micrometastases, in the background of fatty liver; the detection rate of lesions increased from 78.43% (120/153) to 98.69% (151/153), while the accuracy increased from 69.93% to 94.12%, and the difference was statistically significant (χ²=11.719, P=0.0016). The sensitivity and specificity were both greater than 91%, and the positive predictive value was greater than 94%.

Contrast-enhanced ultrasound can significantly improve the detection rate of focal liver lesions, especially micrometastases, and the diagnostic accuracy in the background of fatty liver. As a useful tool, it has important clinical application value in providing tissue microcirculation information for clinical diagnosis.