Contrast-enhanced ultrasound in diagnosing malignancy in the non-cirrhotic liver

Objectives: The aim of our study was to evaluate contrast ultrasound signs in diagnosing malignant liver lesions in the non-cirrhotic liver.

Methods: 86 non-cirrhotic patients with 100 solid liver lesions were enrolled. A baseline gray-scale sonogram was obtained with a multifrequency 4 C convex array probe, followed by contrast-enhanced sonography with a low mechanical index (<0,2). Final diagnosis was confirmed by histology or in case of haemangioma by CT/NMR.

Results: 55 malignant (6 HCC, 46 secondary malignant lesions, 3 cholangiocarcinoma), and 45 benign lesions (8 FNH, 1 von Meyenburg complex, 1 granuloma, 3 adenoma, 21 hemangioma, 2 focal fat storage imbalances, 7 abscesses, one scar, and in one case normal liver) were found.

51/55 malignant but also 17/45 benign lesions showed hypoperfusion in the late phase. In the early phase 22 lesions were hypervascular, 20 had rim enhancement and in 13 lesions there was a non-specific vascularisation.

In all but one malignant lesion an attenuation of the early contrast in the late phase was observed. Only three benign lesions with this later sign were falsely diagnosed as malignant: one adenoma, one epitheloid granuloma, and a scar.

Attenuated contrast in the late phase compared to the early phase as a sign for malignancy had a positive predictive value of 95%, a sensitivity of 98%, a negative predictive value of 98%, and a specificity of 93%.

Conclusions: Attenuated contrast in the late phase compared to the early phase is a helpful sign in contrast enhanced ultrasound to diagnose malignancies.