CHAPTER 1 - Introduction

Abstract

Chronic liver disease (CLD) is a significant cause of morbidity and mortality and an important contributor to the burden of disease and health care utilization worldwide. The epidemiology and distribution of the different causes of CLD vary geographically, by ethnicity and by age group and are rapidly changing. CLD is characterized by progressive and diffuse deposition of fibrous tissue as a response of sustained liver injury or inflammation. Biopsy is the gold standard for staging of fibrosis. However, it is an imperfect test. Its accuracy can be compromised by inadequate sampling, sampling variation, and interobserver variability at the time of interpretation. Most complications of CLD occur once the patient has reached a cirrhotic stage. Clinically, cirrhosis has been classified into two main stages: compensated and decompensated. Within the compensated stage, two substages have been identified based on the severity of portal hypertension. As of now, the diagnosis of clinically significant portal hypertension is established via hepatic vein catheterization, an invasive procedure that carries a small risk of complications; furthermore, reliable measurements are not obtained in centers that do not perform the measurements routinely. The use of noninvasive means for staging, screening, and monitoring CLD, mainly the use of ultrasound-based technologies to determine liver stiffness, is currently favored and has become a cornerstone in the armamentarium of hepatologists around the world.