Magnitude of contrast-enhanced ultrasonography as a noninvasive predictor for hepatic fibrosis: comparison with liver stiffness measurement and serum-based models

Contrast-enhanced ultrasonography for the management of portal hypertension in cirrhosis

Portal hypertension is a major pathophysiological condition in patients with cirrhosis. This accounts for the occurrence and severity of the various manifestations. The degree is determined by the portal pressure or hepatic venous pressure gradients, both of which are obtained by invasive interventional radiological procedures. Ultrasound (US) is a simple and minimally invasive imaging modality for the diagnosis of liver diseases. Owing to the availability of microbubble-based contrast agents and the development of imaging modes corresponding to contrast effects, contrast-enhanced US (CEUS) has become popular worldwide for the detailed evaluation of hepatic hemodynamics, diffuse liver disease, and focal hepatic lesions. Recent advancements in digital technology have enabled contrast-based demonstrations with improved resolution, leading to a wider range of applications. This review article describes the current role, benefits, and limitations of CEUS in the management of portal hypertension.

Advances in ultrasound diagnosis in chronic liver diseases

Chronic liver disease is a major disorder worldwide. A better understanding of anatomy, blood flow, and pathophysiology may be a key issue for their proper management. Ultrasound (US) is a simple and non-invasive diagnostic tool in the abdominal field. Doppler mode offers real-time hemodynamic evaluation, and the contrast-enhanced US is one of the most frequently used modalities for the detailed assessment. Further development in digital technology enables threedimensional (3D) visualization of target images with high resolution. This article reviews the wide ranges of application in the abdominal US and describes the recent progress in the diagnosis of chronic liver diseases.

Assessment of contrast-enhanced ultrasonography of the hepatic vein for detection of hemodynamic changes associated with experimentally induced portal hypertension in dogs

OBJECTIVE To assess the use of contrast-enhanced ultrasonography (CEUS) of the hepatic vein for the detection of hemodynamic changes associated with experimentally induced portal hypertension in dogs. ANIMALS 6 healthy Beagles. PROCEDURES A prospective study was conducted. A catheter was surgically placed in the portal vein of each dog. Hypertension was induced by intraportal injection of microspheres (10 to 15 mg/kg) at 5-day intervals via the catheter. Microsphere injections were continued until multiple acquired portosystemic shunts were created. Portal vein pressure (PVP) was measured through the catheter. Contrast-enhanced ultrasonography was performed before and after establishment of hypertension. Time-intensity curves were generated from the region of interest in the hepatic vein. Perfusion variables measured for statistical analysis were hepatic vein arrival time, time to peak, time to peak phase (TTPP), and washout ratio. The correlation between CEUS variables and PVP was assessed by use of simple regression analysis. RESULTS Time to peak and TTPP were significantly less after induction of portal hypertension. Simple regression analysis revealed a significant negative correlation between TTPP and PVP. CONCLUSIONS AND CLINICAL RELEVANCE CEUS was useful for detecting hemodynamic changes associated with experimentally induced portal hypertension in dogs, which was characterized by a rapid increase in the intensity of the hepatic vein. Furthermore, TTPP, a time-dependent variable, provided useful complementary information for predicting portal hypertension. IMPACT FOR HUMAN MEDICINE Because the method described here induced presinusoidal portal hypertension, these results can be applied to idiopathic portal hypertension in humans.

Non-invasive assessment of portal hypertension and liver fibrosis using contrast-enhanced ultrasonography

Portal hypertension and hepatic fibrosis are key pathophysiologies with major manifestations in cirrhosis. Although the degree of portal pressure and hepatic fibrosis are pivotal parameters, both are determined using invasive procedures. Ultrasound (US) is a simple and non-invasive technique that is available for use worldwide in the abdominal field. Because of its safety and easy of use, contrast-enhanced US is one of the most frequently used tools in the management of liver tumors for the detection and characterization of lesions, assessment of malignancy grade, and evaluation of therapeutic effects. This wide range of applications drives the practical use of contrast-enhanced US for evaluation of the severity of portal hypertension and hepatic fibrosis. The present article reviews the recent progress in contrast-enhanced US for the assessment of portal hypertension and hepatic fibrosis.