Diagnostic Accuracy of Contrast-Enhanced Ultrasound in the Characterization of Focal Liver Lesions: A Prospective Study

Abstract

Background: Accurate characterization of focal liver lesions (FLLs) is critical for treatment planning, but conventional B-mode ultrasound has limited specificity. Contrast-enhanced ultrasound (CEUS) using second-generation microbubble agents offers real-time dynamic vascular assessment without ionising radiation or nephrotoxic contrast. Data from Indian centres remain limited. This study evaluated the diagnostic accuracy of CEUS in characterizing FLLs using contrast-enhanced computed tomography (CECT), contrastenhanced magnetic resonance imaging (CEMRI), or histopathology as the reference standard. Methods: A single-centre, prospective, cross-sectional diagnostic accuracy study was conducted between January 2024 and December 2025. A total of 124 consecutive adult patients with 138 FLLs detected on conventional ultrasound were enrolled. CEUS was performed using sulphur hexafluoride microbubble agent (SonoVue®) following CEUS LIRADS criteria. Two blinded radiologists characterized lesions; discrepancies were resolved by consensus. The final diagnosis was established by CECT/CEMRI in 92 lesions and by histopathology in 46. Results: Among 138 lesions, 78 (56.5%) were benign and 60 (43.5%) were malignant. CEUS correctly characterized 128 of 138 lesions (overall accuracy 92.8%). For differentiating malignant from benign lesions, CEUS showed sensitivity 93.3%, specificity 92.3%, positive predictive value 90.3%, negative predictive value 94.7% and area under the ROC curve 0.928 (95% CI 0.886–0.971). Lesion-specific accuracy was 96.4% for haemangioma, 95.0% for hepatocellular carcinoma, 88.9% for metastasis and 87.5% for focal nodular hyperplasia. Inter-observer agreement was very good (κ = 0.86). No adverse events were recorded. Conclusion: CEUS provided high diagnostic accuracy for characterization of focal liver lesions in an Indian cohort, with safety and operatorfriendliness that support its broader adoption as a first-line problem-solving modality, particularly in patients with contraindications to iodinated or gadolinium-based contrast.