Value of contrast-enhanced ultrasound (CEUS) in Focal Liver Lesions (FLL) with inconclusive findings on cross-sectional imaging

Article type: Research Article

Authors: Auer, Timo Alexander^a | Fischer, Thomas^a | Garcia, Stephan Rodrigo Marticorena^a | Penzkofer, Tobias^{a; b} | Jung, Ernst-Michael^c | Hamm, Bernd^a | Lerchbaumer, Markus Herbert^{a; *}

Affiliations: [a] Department of Radiology, Charité – University Medicine Berlin, Germany | [b] Berlin Institute of Health, Berlin, Germany | [c] University Medical Center Regensburg, Department of Radiology, Regensburg, Germany

Correspondence: [*] Corresponding author: Markus Herbert Lerchbaumer MD, Klinik für Radiologie, Campus Mitte, Charité – Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany. Tel.: +49 30 450 557001; Fax: +49 30 450 557901; E-mail: [email protected].

Abstract: BACKGROUND:Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to evaluate focal liver lesions. CEUS is easy and fast to perform, overcomes the limitations of B-mode US. OBJECTIVE:To evaluate the diagnostic potential of contrast-enhanced ultrasound (CEUS) in focal liver lesions (FLL) with unclear findings on computed tomography (CT) or magnetic resonance imaging (MRI). METHODS:In this single-center retrospective study, 146 patients with at least one FLL underwent additional CEUS of the liver to clarify inconclusive cross-sectional imaging findings. Ultrasonography was performed using B-mode imaging and CEUS after injection of sulphur hexafluoride microbubbles (second-generation contrast agent) within two months after ceMRI or ceCT and interpreted by an experienced radiologist (EFSUMB level 3). Histopathological reports, long-term follow-up or clinical course served as reference standard. RESULTS:Thirty-eight of the 146 patients had malignant and 108 benign FLL. Overall, CEUS had 92% sensitivity (95% -CI, 79–97) and 98% specificity (95% -CI, 93–99) with an AUC of 0.95 in correctly characterizing the lesion as malignant or benign. Sensitivity increased to 98% (95% -CI, 96–100) for benign lesions and decreased to 92% (95% -CI, 78–98) for malignant lesions. CEUS showed the highest diagnostical accuracy in lesion <1 cm with an AUC of 1.000, while the lowest accuracy was achieved in lesions >2 cm with an AUC of 0.924 due to a decreasing specificity of 86% (95% -CI, 87–100). CONCLUSION:CEUS correctly distinguished malignant from benign FLL in cases with inconclusive cross-sectional imaging findings and achieved high levels of diagnostic accuracy. CEUS has added diagnostic value especially in small lesions ≤1 cm while specificity remains limited in larger lesions.

Keywords: CEUS, focal liver lesions, sonography, contrast-enhanced ultrasound, liver ultrasound

DOI: 10.3233/CH-190718

Journal: Clinical Hemorheology and Microcirculation, vol. 74, no. 3, pp. 327-339, 2020