Value of Contrast-Enhanced Ultrasound in Differential Diagnosis of Focal Liver Lesions

Purpose: to evaluate the diagnostic value of contrastenhanced ultrasound (CEUS) with SonoVue in differential diagnosis of focal liver lesions (FLL) in a multidisciplinary clinic in Russian Federation. Materials and methods . Bolus intravenous administration of 1.2 ml of SonoVue (Bracco Swiss CA, Switzerland) followed with 5ml saline flush was used for liver CEUS. We utilized the scanners Mindray DC-8 (Mindrаy, China), Logiq S8 (GE, USA), Philips Epiq 7 (Philips, Holland), SonoScape S9 (SonoScape, China), Hitachi Ascendus (Hitachi, Japan) with 3.0–5.0 MHz convex probes in specialized “contrast” mode with low mechanic index (MI 0.08–0.1). The study conferred 73 patients in the age between 18 and 84 years (mean age 49 years) with FLL. CEUS was performed in 22 patients with previously verified diagnosis, while the rest of patients underwent CEUS before the final diagnosis. Contrast-enhanced liver CT was performed in all patients. In 49 (67.12%) of 73 cases, a pathology was performed after a targeted core-needle biopsy or autopsy. Qualitative features of US contrast enhancement of FLL were evaluated. Results . Qualitative aspects of CEUS for differentiation of FLL were defined. The principal sign for diagnosis between benign and malignant masses with CEUS was hypoenhancement of malignant lesions in comparison to surrounding normal parenchyma in portal and late venous phase (p ≤ 0.01). Alternatively, hyper- or isoenhancement throughout late venous phase was characteristic for benign FLL. Diffuse heterogeneous contrast enhancement was indicative of malignant FLL, and homogeneous – for benign. Additional diagnostic feature (p ≤ 0.05) was the type of contrast enhancement in the arterial phase. Heterogeneous diffuse contrast enhancement was observed in malignant FLL, while homogeneous – in benign FLL. Peripheral nodular contrast enhancement with centripetal filling was characteristic for liver hemangioma, centrifugal filling with “spoke-wheel” vascular pattern – for FNH, and peripheral rim-like hyperenhancement with rapid achievement of hypoenhancement at the beginning of the portal phase – for liver metastasis. Conclusion. Complex analysis of qualitative characteristics of CEUS with SonoVue is a promising option for differential diagnosis of FLL (sensitivity 92.85%, specificity 91.3%, diagnostic accuracy 92.15%) and can be utilized in daily practice.