Imaging Based Methods of Liver Fibrosis Assessment in Viral Hepatitis: A Practical Approach.

Hicham Khallafi,Kamran Qureshi

doi:10.1155/2015/809289

Abstract

Liver fibrosis represents the repair mechanism in liver injury and is a feature of most chronic liver diseases. The degree of liver fibrosis in chronic viral hepatitis infections has major clinical implications and presence of advanced fibrosis or cirrhosis determines prognosis. Treatment initiation for viral hepatitis is indicated in most cases of advanced liver fibrosis and diagnosis of cirrhosis entails hepatology evaluation for specialized clinical care. Liver biopsy is an invasive technique and has been the standard of care of fibrosis assessment for years; however, it has several limitations and procedure related complications. Recently, several methods of noninvasive assessment of liver fibrosis have been developed which require either serologic testing or imaging of liver. Imaging based noninvasive techniques are reviewed here and their clinical use is described. Some of the imaging based tests are becoming widely available, and collectively they are shown to be superior to liver biopsy in important aspects. Clinical utilization of these methods requires understanding of performance and quality related parameters which can affect the results and provide wrong assessment of the extent of liver fibrosis. Familiarity with the strengths and weaknesses of each modality is needed to correctly interpret the results in appropriate clinical context.

Highlights

Liver fibrosis is a common pathway of liver injury for multiple chronic liver conditions
The techniques included can be divided into four main groups: (A) shear wave elastography technique based on mechanically generated impulse that includes Transient Elastography (FibroScan); (B) shear wave elastography techniques based on the acoustic beam that includes 2D shear wave elastography/point shear wave elastography/acoustic radiation force impulse; (C) real-time technique based elastography; and (D) magnetic resonance elastography
Boursier et al showed that biomarkers noninvasive tools in conjunction with FibroScan liver stiffness evaluation could obviate the need for liver biopsy with over 86.7% accuracy [30]

Summary

Introduction

Liver fibrosis is a common pathway of liver injury for multiple chronic liver conditions. Assessment of the severity of hepatic fibrosis is essential for determining the prognosis of patients with chronic viral hepatitis and estimating the urgency of antiviral therapy [1]. The accurate evaluation of fibrosis using liver biopsy is complicated by sampling error and interobserver variation in staging, when inadequate sampling occurs [4]. Some of the noninvasive methods of liver fibrosis assessment have better diagnostic value than liver biopsy in chronic liver diseases and are safe to perform. The noninvasive methods are increasingly replacing invasive liver biopsy in clinical practice due to patient wariness of the morbidity associated liver biopsy and physician ease of clinical use with accuracy. We will focus on imaging based methods and describe the technical aspects, performance accuracy, meaningful utilization, and incorporation in clinical practice of available elasticity based methods of liver fibrosis assessment (elastography)

Elastography Imaging

Findings

Conclusion