Portal hypertension is a major pathophysiology in patients with cirrhosis. Portal pressure is the gold standard to evaluate the severity of portal hypertension, and radiological intervention is the only procedure for pressure measurement. Ultrasound (US) is a simple and noninvasive imaging modality available worldwide. B-mode imaging allows broad applications for patients to detect and characterize chronic liver diseases and focal hepatic lesions. The Doppler technique offers real-time observation of blood flow with qualitative and quantitative assessments, and the application of microbubble-based contrast agents has improved the detectability of peripheral blood flow. In addition, elastography for the liver and spleen covers a wider field beyond the original purpose of fibrosis assessment. These developments enhance the practical use of US in the evaluation of portal hemodynamic abnormalities. This article reviews the recent progress of US in the assessment of portal hypertension.
Contrast Media ; Elasticity Imaging Techniques ; Fibrosis ; Hemodynamics ; Humans ; Hypertension, Portal* ; Liver ; Liver Diseases ; Portal Pressure ; Spleen ; Ultrasonography* ; Ultrasonography, Doppler

OBJECTIVETo review the updated research on direct antiviral agents (DAAs)-including regimens for hepatitis C virus (HCV), and focus on "difficult-to-treat" HCV-infected patients.

DATA SOURCESThe literature concerning DAAs and hepatitis C cited in this review was collected from PubMed and Google Scholar databases published in English up to July 2013.

STUDY SELECTIONData from published articles regarding HCV and DAAs in clinical trials and in clinical use were identified and reviewed.

RESULTSIt was recognized that some "difficult-to-treat" patients would still exist, even though stronger treatments using such as DAAs, including telaprevir and boceprevir, which lead to higher sustained virological response rates, are available. Such patients include those with advanced fibrosis/cirrhosis, elderly persons, children, HCV-human immunodeficiency virus co-infected patients, HCV-infected recipients, and so on.

CONCLUSIONSCertain "difficult-to-treat" patients would still exist, even though stronger treatment is available. Although evidence from clinical trials is still lacking, interferon-sparing regimens could have stronger effects for eradicating HCV in such cases.

Antiviral Agents ; pharmacology ; therapeutic use ; Hepacivirus ; drug effects ; pathogenicity ; Hepatitis C, Chronic ; drug therapy ; Humans