Intraoperative Contrast Enhanced Ultrasound (IO-CEUS) and Color Coded Elastography (CCE) for Characterization of Liver Lesion Before Surgical Resection

Abstract

To evaluate if IO-CEUS and CCE allow a differentiation between malignant and benign liver lesions in comparison to histopathology. Retrospective evaluation of digitally stored intraoperative CEUS examinations. IO-CEUS and CCE of 49 liver lesions were compared to histopathology following surgical resection. Examinations were performed by one experienced examiner using a multifrequency linear probe (6-9 MHz, LOGIQ E9/GE). Loops of CEUS were evaluated during the arterial (15-45s), the portal venous (60-90s) and the late-venous phase (2-5 min). Characterization of the CCE using digital cine-loops >10 s, based upon a color coding system. Semi-quantitative evaluation of the lesions’ stiffness based upon a default scaling of 0-6 (0 low up to 6 high) using 7 ROIs (2 in the center, 5 in the marginal zone). Lesion diameter from 7 - 54 mm, mean 2,5 cm. All 44 malignant lesions (13 HCCs, 8 CCCs, 23 metastases) displayed a portal venous washout. 3 lesions that could not be characterized definitely using IO-CEUS and CCE, were found to be a partially thrombosed hemangioma, a granuloma and a dystrophic fibrosis by histopathology. 2 lesions were correctly diagnosed as complicated cysts using IO-CEUS. Overall accuracy of IO-CEUS was 90%, specificity was 96%. Using CCE, malignant lesions were found to be inhomogenous, only partially indurated in 12 lesions, with a scaling of 5. Only in 8/49 lesions central indurations were visible (scaling 4-6). Overall accuracy was 69%, specificity was 94%. IO-CEUS offers clear benefits for localization and characterization of liver lesions. CCE only partly allows a correct characterization of lesions.