The role of ultrasound in the differential diagnosis of liver tumors
Background. Liver lesions are increasingly found in a huge number of patients. Ultrasound (US) is the method of choice in liver lesion characterization. The limitations of traditional US techniques are well known. Multiparametric ultrasound (MPUS) includes multiple facets of the US examination, and their combination can significantly improve the diagnostic capabilities of the method.Objective. To evaluate the capabilities of MPUS in the differential diagnosis of liver tumors.Material and Methods. A retrospective analysis included 172 patients with morphologically confirmed liver tumors. All patients underwent an MPUS examination.Results. Traditional US techniques have a rather low specificity in the differential diagnosis of liver neoplasms: the sign of “contour clarity” was typical for hemangiomas, hepatocellular adenomas (HCA), liver metastases and was recorded in 82, 100, 96% cases, respectively; heterogeneous echostructure was noted in all nosological entities, groups of hepatocellular carcinomas (HCC), liver metastases and HCA were characterized by foci of various types of echogenicity. Specific symptoms were discovered in patients with liver metastases (32%) and focal nodular hyperplasia (FNH) (96%). Intratumoral blood flow was recorded in 34 (19.7%) cases. The study of spectral characteristics was possible only in 11 (6.4%) patients. Statistically significant differences in contrast-enhanced US parameters “contrasting onset in focus” were found between the groups “FNH & hemangioma” (р < 0.000046), “FNH & HCA” (р < 0.006293), “MTS & FNH” (р < 0.028125), “FNH & HCC” (р < 0.024933), “maximum fill-in time” - “FNH & hemangioma” (р < 0.012590), “FNH & HCC” (р < 0.007983), “MTS & HCC” (р < 0.000243). Statistically significant differences in the wash-out time were obtained in “MTS & HCC” and “MTS & HCA” groups.Conclusion. Conventional US should be used as basic screening, follow-up and navigation in the neoplastic biopsy. Contrast-enhanced US within MPUS is currently a well-established technique which allows a more precise and confident diagnosis of liver tumors.