Utilization of Contrast-Enhanced Ultrasound in Diagnosis of Focal Liver Lesions

Background and aims: Focal liver lesions (FLL) are one of the most common indications for hepatology and hepatobiliary surgery consultation. In this retrospective study, we aim to assess if contrast-enhanced ultrasound (CEUS) can address diagnostic dilemmas in the evaluation of indeterminate liver lesions by identifying characteristics of indeterminate FLL on CEUS and correlating these with cross-sectional imaging and pathology findings. Methods: We retrospectively reviewed all patients who underwent CEUS evaluation for liver lesions over a 28-month period (Oct 2020 to Jan 2023) at the University of Kentucky. To assess the relationship between CEUS results and the corresponding CT, MRI, and/or pathologic findings, the McNemar-Bowker tests were performed. Results: Twenty-nine patients were included (after two exclusions from a total n of 31). Mean age was 54 years, 62% were female, and 48% had underlying cirrhosis. Of the 29 patients with initial cross-sectional imaging, the initial results showed malignancy or likely malignant lesion in 6 patients and benign or likely benign lesion in 6 patients. The remaining 17 patients had inconclusive/indeterminate results. CEUS clarified an "indeterminate" CT/MRI result 15 times out of 17 (88.2%), moving the diagnosis to "benign" 11 times while suggesting "malignant" only four times. When aggregating indeterminate cross-sectional results with either benign or malignant categories suggested by CEUS, CEUS never reversed a benign CT/MRI diagnosis but often reversed a malignant CT/MRI diagnosis. Conclusion: CEUS provided a definitive diagnosis of indeterminate liver lesions in approximately 90% of patients and avoided the need for biopsy in most patients. In cases where the liver lesions were biopsied, CEUS accurately distinguished malignant versus benign lesions as confirmed by biopsy findings. CEUS, therefore, has the potential to provide a precise diagnosis for the majority of indeterminate lesions.