Contrast-enhanced ultrasound with SonoVue: differentiation between benign and malignant focal liver lesions in 317 patients.

Objective: The aim of the study was to investigate the ability of contrast-enhanced sonography (CEUS) with the contrast agent SonoVue to differentiate between benign and malignant focal liver lesions.

Methods: In a prospective study, we examined 317 patients (204 males, 113 females, aged 59 +/- 12 years) with focal liver lesions detected by B-mode gray-scale sonography. After intravenous injection of 1.2 mL SonoVue, the liver was examined continuously for 3 minutes using low-MI sonography with contrast-specific software. Final diagnosis was established by histopathology, CT, MRI, or HIDA-scintigraphy.

Results: Two hundred nine patients had malignant focal lesions, including 107 hepatocellular carcinomas, 70 metastases, 26 cholangiocellular carcinomas, and 6 other types of malignancy. One hundred eight patients had benign focal lesions, including 30 regenerative nodules, 30 hemangiomas, 13 cases of focal nodular hyperplasia, 12 abscesses, 8 cases of necrosis, 7 cases of focal steatosis areas, and 8 other benign lesions. Hypoenhancement or no enhancement in the late phase was found in 91% of the malignant lesions but in only 37% of the benign lesions (p < 0.001, sensitivity = 64%, specificity = 93%). Hyperenhancement in the late phase was found in 20% of the benign lesions but in none of the malignant lesions (p < 0.001, sensitivity = 21%, specificity = 100%). Hyperenhancement in the early phase with diffuse complete enhancement was found in 30% of the patients with malignant lesions but in only 2% of the patients with benign lesions (p < 0.001, sensitivity = 30%, specificity = 98%). CEUS had a sensitivity of 90%, a specificity of 99%, and an accuracy of 89% in the diagnosis of malignant liver lesions.

Conclusions: CEUS is helpful in the differentiation between benign and malignant focal liver lesions.