Non-pulsatile hepatic and portal vein waveforms in patients with liver cirrhosis: concordant and discordant relationships

Diagnostic Value of Hepatic Vein Ultrasound in Early Detection of Liver Cirrhosis

Background

Cirrhosis is a common disease that destroys liver cells, and it has various etiologies. The early diagnosis of cirrhosis can be effective in improving prognosis. Considering the availability and affordability of ultrasound devices throughout the world, in this study we evaluated the diagnostic value of hepatic vein ultrasound examination in the early detection of liver cirrhosis.

Materials and Methods

In this study, 45 patients referred to the radiology department of Ghaem Hospital for liver biopsy were evaluated for changes in the hepatic veins under ultrasound with a transducer of 5-7MHz. One piece of the hepatic vein was selected for ultrasound, and the wall of hepatic veins was examined for straightness and uniformity of echogenicity. Subsequently, patients underwent biopsy by ultrasound guide. Of all the study subjects, eight patients presented mild chronic hepatitis without fibrosis, four patients were diagnosed with fatty liver, and 33 patients had severe cirrhosis or chronic hepatitis with fibrosis.

Results

Our results showed that hepatitis patients with or without fibrosis had irregular and wavy hepatic vein wall (impairment in straightness) with non-uniform echo (impairment in uniformity of echogenicity). While patients without hepatitis and cirrhosis, but diagnosed with fatty liver, had a smooth and regular hepatic vein wall with a uniform echo.

Conclusion

The present study showed that hepatic vein examination in terms of echogenicity and straightness could be used to diagnose hepatitis, its severity as well as its course towards fibrosis and cirrhosis.

Altered Doppler flow patterns in cirrhosis patients: an overview

Doppler ultrasonography of the hepatic vasculature is an integral part of evaluating precirrhotic and cirrhotic patients. While the reversal of the portal venous flow is a well-recognized phenomenon, other flow patterns, although not as easily understood, may play an important role in assessing the disease status. This article discusses the different characteristic flow patterns observed from the portal vein, hepatic artery, and hepatic vein in patients with liver cirrhosis or related complications and procedures. Knowledge of these different flow patterns provides additional information that may reinforce the diagnosis of cirrhosis, help in staging, and offer prognostic information for determining the direction of therapy. Doppler ultrasonography is invaluable when liver transplantation is being considered and aids in the diagnosis of cirrhosis and portal hypertension.

Latest developments in the imaging of fibrotic liver disease

According to the World Health Organization, liver cirrhosis accounted for 1.8% of all deaths in Europe, causing about 170,000 deaths per year. Approximately 29 million persons in the EU suffer from chronic liver disease and this trend is on the rise. Liver disease is the EU's fifth most common cause of death accounting for at least one in six deaths. Early detection and monitoring of fibrosis has the potential to direct management of these chronic liver diseases and avert morbidity and mortality. Although the available techniques are in their infancy and the very early stages of fibrosis are difficult to detect, there have been significant advances in imaging over the last decade that has resulted in the use of these new imaging techniques being introduced into the patient pathway. This review explores the accuracies of these imaging techniques, their role in the management of patients, and the potential for the future.

Sonographic classification of draining pathways of obstructed hepatic veins in Budd-Chiari syndrome

PURPOSE

To describe and propose a sonographic classification of the blood-draining pathways of obstructed hepatic veins in Budd-Chiari syndrome.

METHODS

This retrospective study included 206 patients with hepatic vein obstructions who underwent sonographic examination. We evaluated the afflicted hepatic veins, as well as the course, orifice, blood flow direction of draining veins, and communicating branches. Results were classified and compared with digital subtraction angiography and computed tomography angiography.

RESULTS

Of 618 hepatic veins in 206 patients, 542 were obstructed. The blood-draining pathways were classified as hepatic vein-accessory hepatic vein (131/206), hepatic vein-hepatic vein/accessory hepatic+hepatic vein (49/206), and, less frequently, collateral pathways (26/206). Blood was drained from obstructed hepatic veins to the inferior vena cava, right atrium, para-umbilical veins, or hepatic subcapsular veins through communicating branches of various number and diameters. Doppler signals were obtained from the draining veins.

CONCLUSIONS

Sonography provides accurate information regarding the blood-draining pathways of obstructed hepatic veins in Budd-Chiari syndrome, which may be helpful for treatment and follow-up.

Evaluation of portal venous velocity with Doppler ultrasound in patients with nonalcoholic fatty liver disease

PURPOSE

We examined the relationship between portal venous velocity and hepatic-abdominal fat in patients with nonalcoholic fatty liver disease (NAFLD), using spectral Doppler ultrasonography (US) and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In this prospective study, 35 patients with NAFLD and 29 normal healthy adults (control group) underwent portal Doppler US. The severity of hepatic steatosis in patients with NAFLD was assessed by MRI through chemical shift imaging, using a modification of the Dixon method. Abdominal (intra-abdominal and subcutaneous) fat was measured by MRI.

RESULTS

The difference in portal venous velocity between the patients with NAFLD and the control group was significant (p < 0.0001). There was no correlation between the degree of abdominal or hepatic fat and portal venous velocity (p > 0.05). There were strong correlations between the hepatic fat fraction and subcutaneous adiposity (p < 0.0001), intraperitoneal fat accumulation (p = 0.017), and retroperitoneal fat accumulation (p < 0.0001).

CONCLUSION

Our findings suggest that patients with NAFLD have lower portal venous velocities than normal healthy subjects.

Evaluation of hepatic fibrosis with portal pressure gradient in rats

MRI has the potential of providing a noninvasive assessment of liver pathology. This work introduces a portal pressure gradient (PPG) model derived from fluid mechanics, where the PPG is proportional to the average velocity and inversely proportional to the vessel area in the upper part of portal vein. Using a phase-contrast spoiled gradient echo sequence, the PPG model was verified in a phantom study and was tested in an animal study using 35 rats with various degrees of hepatic fibrosis induced by carbon tetrachloride (CCl(4)). Histological examination was conducted to determine the severity of hepatic fibrosis. The fibrosis score monotonically increased with the duration of CCl(4) treatment. The PPG was highly correlated with nonzero fibrosis scores (r(2) = 0.90, P < 0.05). There was a significant difference between control and cirrhosis groups (P < 0.0006, alpha < 0.0018). The difference between control and fibrosis (noncirrhosis) groups (P < 0.002, alpha < 0.006) was also significant. Without the administration of any contrast agent, the MRI-PPG approach shows promise as a noninvasive means of evaluating liver fibrosis.