Stratification of Patients With Chronic Liver Disease Using Multi Spectral CT

This is a retrospective study, in which a FDA approved imaging device (spectral CT scanner) currently used for several clinical applications will be evaluated for feasibility of studying chronic liver disease (this application has not yet been validated). Tomographic imaging has assumed a fundamental role in patients with Chronic Liver Disease (CLD) to screen patients for hepatocellular carcinoma (HCC), and, is increasingly being explored as a noninvasive alternative for characterizing liver fibrosis. The overarching goal of this study is to improve noninvasive characterization of liver fibrosis through spectral CT. Hypothesis: concentration of iodine-based contrast agent in the liver parenchyma during the delayed phase, as measured with spectral CT imaging, increases monotonically with Ishak fibrosis score obtained from liver biopsy. This hypothesis is supported by the literature and our preliminary data, described in the references section (Lamb et al. 2015). We will evaluate multiphase spectral CT images consisting of the arterial phase, 2-minute delayed phase, and 5-minute delayed phase. Fibrosis will be assessed on both delayed phase images, where it is assumed that any remaining contrast agent, in the liver, is due to the presence of fibrosis. This type of multiphase protocol can still be used to image CLD patients with spectral CT for HCC detection and, thus, will not interfere with liver lesion workup and evaluation.