Characterization of focal liver lesions with SonoVue~-enhanced sonography: International multicenter-study in comparison to CT and MRI

AIM: To evaluate in a multicenter study whether the sonographic characterization of focal liver lesions can be improved using SonoVueüà-enhancement; and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: One hundred and thirty four patients with one focal liver lesion detected in baseline ultrasound (US) were examined with conventional US, contrastenhanced US (n = 134), contrast-enhanced CT (n = 115) and/or dynamic contrast-enhanced MRI (n = 70). The lesions were classified as malignant, benign or indeterminate and the type of lesion was determined. The f inal diagnosis based on the combined information of all imaging examinations, clinical information and histology (n = 32) was used. Comparisons were made to see whether the addition of contrast-enhanced US led to the improvement of the characterization of doubtful focal liver lesions. RESULTS: In comparison with unenhanced US, SonoVue markedly improves sensitivity and specificity for the characterization (malignant/benign) of focal liver lesions. In comparison with CT and/or dynamic MRI, SonoVueüà -enhanced sonography applied for characterization of focal liver lesions was 30.2% more sensitive in the recognition of malignancy and 16.1% more specific in the exclusion of malignancy and overall 22.9% more accurate. In the subgroup with confirmative histology available (n = 30), sensitivity was 95.5% (CEUS), 72.2% (CT) and 81.8% (MRI), and specif icity was 75.0% (CEUS), 37.5% (CT) and 42.9% (MRI). The sensitivity and specif icity of CEUS for the identif ication of focal nodular hyperplasia (FNH) and hemangiomas was 100% and 87%, resulting in an accuracy of 94.5%. CONCLUSION: SonoVueüà-enhanced sonography emerges as the most sensitive, most specif ic and thus most accurate imaging modality for the characterization of focal liver lesions.

Contrast-enhanced ultrasonography in the evaluation of incidental focal liver lesions: A cost-effectiveness analysis

AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magnetic resonance imaging(MRI). METHODS Between 2010 and 2015, our prospective study enrolled 459 patients with incidentally found FLLs. The biological nature of FLLs was assessed by CEUS in all patients. CT or MRI examinations were added in unclear cases. The sensitivity and specificity of CEUS were calculated. The total costs of CEUS examinations and of the added examinations performed in inconclusive cases were calculated. Afterwards, the theoretical expenses for evaluating incidentally discovered FLLs using CT or MRI as the first-line method were calculated. The resultswere compared. RESULTS The total cost of the diagnostic process using CEUS for all enrolled patients with FLLs was 75884 USD. When the expenses for additional CT and MRI examinations performed in inconclusive cases were added, the total cost was 90540 US dollar(USD). If all patients had been examined by CT or MR as the first-line method, the costs would have been 78897 USD or 384235 USD, respectively. The difference between the cost of CT and CEUS was 3013 USD(4%) and that between MRI and CEUS was 308352 USD(406.3%). We correctly described 97.06% of benign or malignant lesions, with 96.99% sensitivity and 97.09% specificity. Positive predictive value was 94.16% and negative predictive value was 98.52%. In cases with 4 and more lesions, malignancy is significantly more frequent and inconclusive findings significantly less frequent(P < 0.001).CONCLUSION While the costs of CEUS and CT in evaluating FLLs are comparable, CEUS examination is far more costeffective in comparison to MRI.