Resolution of indeterminate MRI with CEUS in patients at high risk for hepatocellular carcinoma

Jinghui Hu,Kelly W Burak,Stephanie R Wilson,Deepak Bhayana

doi:10.1007/s00261-019-02181-2

Abstract

PurposeTo show the contribution of CEUS to characterization of indeterminate MRI observations in high-risk patients for hepatocellular carcinoma (HCC).MethodsFrom July to December 2015, 42 consecutive patients referred to CEUS with indeterminate MRI scans comprise our study cohort. There are 50 indeterminate nodule-like observations and 10 arterial phase hyperenhancing foci, suggesting pseudolesions/arterio-portal shunts. MRI and CEUS lesions are classified according to their enhancement features in all phases and Liver Imaging and Reporting Data System (LI-RADS) in a blind read format. Clinical pathologic correlation and 24 months follow-up are performed.ResultsA majority, 37/50 (74%), of indeterminate nodule-like observations have arterial phase enhancement without washout on MRI. CEUS further characterizes enhancement and shows washout in 14/37 (38%). In total, CEUS diagnoses 16 malignant lesions in 14 patients including 14 HCC and 2 ICC. 12/16 (75%) malignant lesions are confirmed by biopsy or follow-up. Ultrasound identification of a nodule differentiates real nodules from pseudolesions. Of the ten suspected arterial-portal shunts on MRI, two show a real nodule on ultrasound, confirmed as an HCC and a regenerative nodule. 15/42 (36%) patients have LI-RADS escalated from LR-3 or 4 on MRI to LR-4 or 5 on CEUS. Overall, the sensitivity of CEUS is (13/16) 81.3% and specificity is (37/37) 100% for malignant diagnosis.ConclusionGrayscale ultrasound detects true nodules. Dynamic CEUS detects and characterizes washout, correctly predicting HCC. CEUS is complimentary to MRI and can serve as a problem-solving tool when MRI is indeterminate.

Highlights

Hepatocellular carcinoma (HCC), the most common primary liver malignancy, evolves by stepwise progression from a benign regenerative nodule (RN) into a dysplastic nodule (DN) prior to the development of well, moderately and poorly differentiated HCC [1,2,3]
Between July and December 2015, 42 consecutive patients with indeterminate MRI results were referred to our tertiary ultrasound facility for liver CEUS as part of standard care, where they were prospectively recruited for our study
From group 1, within the 28 observations showing a nodule on ultrasound, CEUS diagnoses 16/28 (57%) malignant nodules in 14 patients, including 14 HCC in 12 patients and 2 ICC in 2 patients. 12/16 (75%) are confirmed with reference standard, while the rest are treated immediately without biopsy. 11/28 (39%) nodules

Summary

Introduction

Hepatocellular carcinoma (HCC), the most common primary liver malignancy, evolves by stepwise progression from a benign regenerative nodule (RN) into a dysplastic nodule (DN) prior to the development of well, moderately and poorly differentiated HCC [1,2,3]. The vascular changes which occur with the progression of cirrhotic nodules give the appearance of arterial phase (AP) hyperenhancement (APHE) and washout (WO) with contrast administration. MRI is the mainstay for liver imaging in most tertiary institutions in North America. On MRI with gadolinium, typical HCC shows APHE and portal venous (PVP) or delayed phase (DP) WO, with signal changes on T1, T2, and diffusion weighted imaging (DWI) [4,5,6]. Stringent criteria for HCC have been developed by ACR LI-RADS®v2018 as LI-RADS (LR)-5 [7].

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