Hepatic vein transit time of second-generation ultrasound contrast agent: new tool in the assessment of portal hypertension.

PURPOSE: It has been demonstrated that Doppler waveform of the hepatic vein (normally triphasic) is transformed into a biphasic or monophasic waveform in cirrhotic patients. The compressive mechanism of liver tissue has been considered up till now the cause of this change. Moreover, cirrhotics show, after USCA injection, a much earlier HVTT due to intrahepatic shunts. Our aim was to prospectively evaluate the correlation between Doppler pattern of hepatic vein and HVTT of a second-generation USCA; we also correlated HVTT with the most common indexes of portal hypertension. METHODS: We enrolled 38 participants: 33 cirrhotics and 5 healthy controls. Doppler shift signals were obtained from the right hepatic vein. To characterize the hepatic vein pattern, we used the hepatic vein waveform index (HVWI). This index becomes >1 with the appearance of the triphasic waveform. We recorded a clip from 20 s before to 2 min after a peripheral intravenous bolus injection of 2.4 ml of USCA (sulfur hexafluoride).The time employed by USCA to cross the liver from the hepatic artery and portal vein to the hepatic vein was defined as HA-HVTT and PV-HVTT, respectively. RESULTS: Cirrhotics with low HVWI showed an earlier transit time; participants with higher HVWI had a longer transit time (p < 0.001). HVTT was earlier as MELD, Child-Pugh score and spleen diameter increased. Patients with ascites and varices of large size had significantly shorter transit times. CONCLUSIONS: Abnormal hepatic vein Doppler waveform in cirrhotic patients could be due to intrahepatic shunts. HVTT could be useful in the non-invasive evaluation of portal hypertension.

Enhanced liver fibrosis test as a reliable tool for assessing fibrosis in nonalcoholic fatty liver disease in a clinical setting.

BACKGROUND: Liver fibrosis is the main determinant and predictor of the clinical course of nonalcoholic fatty liver disease (NAFLD). To date, a liver biopsy is still considered the gold standard for staging fibrosis. The aim of this study was to investigate the diagnostic accuracy of the commercial enhanced liver fibrosis (ELF) test manufacturer's cutoff value (≥9.8) in identifying severe fibrosis for adult patients with histologically confirmed NAFLD. METHODS: We tested the ELF test in a clinical practice, prospective cohort of 82 consecutive patients who consecutively underwent percutaneous liver biopsy. RESULTS: All stages of liver fibrosis were represented in our cohort, and severe fibrosis was present in 15 of 82 patients (18.3%). The stage of fibrosis was significantly associated with ELF score (Spearman's rho = 0.483, p<0.001). The commercial ELF test manufacturer's cutoff identified severe fibrosis with good sensitivity (86.7%; 95% confidence interval [95% CI], 0.69-1.04) and high specificity (92.5%; 95% CI, 0.86-0.99), with a positive predictive value of 72% and negative predictive value of 97%. CONCLUSIONS: Our data could support the use of the ELF test in clinical practice.