Imaging diagnosis and staging of hepatocellular carcinoma

Despite the incremental technological advances in cross-sectional imaging techniques [ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI)], there is still some concern that the imaging technology available today is inadequate for appropriate prioritization for liver transplantation (LT) because it cannot provide a sufficiently accurate diagnosis of hepatocellular carcinoma (HCC) on a per-nodule basis or sufficiently accurate disease staging on a per-patient basis. In a recent study, a retrospective analysis of data from the United Network for Organ Sharing (which oversees solid organ transplantation in the United States) compared preoperative findings by cross-sectional imaging with postoperative explant pathology findings; in comparison with the pathological stages of the explanted livers, imaging was found to have underestimated or overestimated the tumor burden in approximately one-fourth of the cases.1 One might speculate that this finding not only is due to the inherent shortcomings of the cross-sectional imaging techniques that are generally available for the liver but also reflects significant differences in the technical specifications of scanner hardware and software, imaging protocols, and interpretive expertise, the lack of standardization of the language used in imaging reports, and the absence of widely accepted diagnostic criteria. Here we discuss possible pathways to consensus positions on the following issues: 1The minimal technical requirements for US, CT, and MRI.2The minimal requirements for operator expertise.3The standardization of imaging reports.4The classification of nodules on the imaging workup.5The staging of HCC.6The standardization of the evaluation of the results of locoregional therapy (LRT).7The standardization of surveillance for an early HCC diagnosis in patients listed for LT