title: Hepatic vein transit time of second-generation ultrasound contrast agent: new tool in the assessment of portal hypertension.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of VI Internal Medicine, IRCCS Fondazione Policlinico San Matteo, Viale Camillo Golgi, 19, 27100 Pavia, Italy.
authors.forename: Siciliani
authors.identifier: 0000-0002-6905-7748
authors.initials: S
authors.lastname: Luisa
authors.affiliation: Department of Internal Medicine, Catholic University of Rome, Rome, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Vitale
authors.affiliation: Department of Internal Medicine, Catholic University of Rome, Rome, Italy.
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Sorbo
authors.affiliation: Department of Internal Medicine, Catholic University of Rome, Rome, Italy.
authors.forename: Pompili
authors.initials: P
authors.lastname: Maurizio
authors.affiliation: Department of Internal Medicine, Catholic University of Rome, Rome, Italy.
authors.forename: Rapaccini Gian
authors.initials: RG
authors.lastname: Lodovico
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging; D006503:Hepatic Veins / Q000000981:diagnostic imaging*; D006801:Humans; D006975:Hypertension, Portal / Q000000981:diagnostic imaging*; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D018608:Ultrasonography, Doppler / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Cirrhosis; Hepatic vein transit times; Hepatic vein waveform; Non-invasive procedure; Portal hypertension; Ultrasound contrast agent