E4858. Imaging Review of Benign Hepatobiliary Pathology
  1. Shane Dunnion; Joint Department of Medical Imaging, University of Toronto
  2. Ciara O'Brien; Joint Department of Medical Imaging, University of Toronto
The incidence of liver disease is increasing worldwide, partly due to ageing population and advances in cross-sectional imaging. Ultrasound is often the first imaging modality in evaluating and screening for liver pathology given availability and low cost. Multiphase CT imaging incorporates enhancement characteristics into the diagnostic analysis and is also readily accessible. Excellent tissue contrast, enhancement resolution, and the ability to give better and more accurate information about liver pathology means MRI is the optimal modality for assessing liver disease. Discriminating benign from malignant pathology is essential to avoid unnecessary or incorrect management. In this educational exhibit, we will present a multimodality review of benign pathology affecting the liver, including focal liver lesions and diffuse liver disease. We will stratify diffuse liver disease based on the underlying pathological process. We will also present a wide spectrum of cases of benign acquired and congenital biliary disease.

Educational Goals / Teaching Points
Understand the role of multimodality imaging in investigation of benign liver disease. Understand the pathophysiology of common and uncommon benign disease of the liver. Illustrate typical and atypical imaging findings of benign focal liver lesions, diffuse liver parenchymal, and biliary pathology.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Benign liver tumors are a heterogeneous group of lesions without clinical features of malignancy, which are often incidental findings. We will describe the pathophysiology and radiological features of focal benign liver lesions, including hemangioma, focal nodular hyperplasia, adenoma, and infections lesions. The liver plays an essential role in the metabolism of amino acids, carbohydrates, lipids, and the synthesis of proteins. The pathophysiology of diffuse parenchymal disease usually represents the failure of a metabolic pathway. Diffuse parenchymal diseases can be classified into three wide categories based on the underlying pathology including: storage (hepatic steatosis, iron overload, and lipid storage disease); inflammatory (sarcoidosis and cirrhosis); and vascular (Budd Chiari, Hepatic venoocclusive disease, hepatic peliosis, and Abernethy Syndrome). We will describe the pathological process and present multimodality imaging findings in these diffuse liver processes. A variety of benign biliary pathologies are also increasingly being detected. These include congenital anomalies, such as choledochal cysts or biliary hamartomas, and acquired diseases, such as cholangitis. We will present a cohort of cases depicting benign bile duct disease, describe the imaging findings of the spectrum of sclerosing cholangitis, with a particular emphasis on a systemic approach to differential diagnosis of sclerosing cholangitis.

The spectrum of benign liver disease includes a broad range of different entities, including focal liver lesions, diffuse liver disease, as well as biliary disease. Familiarity with the pathogenesis and imaging features of benign liver disease can aid radiological diagnoses and guide appropriate management.