Hepatic Venous Waveform Research Articles

Echo Rounds: Intraoperative Doppler Assessment of Transjugular Intrahepatic Shunt Flow Using Transesophageal Echocardiography.

The use of intraoperative transesophageal echocardiography (TEE) to assess venous congestion of the liver due to right heart dysfunction is well established, predominately through the Doppler interrogation of the hepatic and portal venous waveforms. Transjugular intrahepatic portosystemic shunts (TIPSs) are artificial intraparenchymal tracts through the liver that are placed to decompress the portal circulation in the setting of portal hypertension, most commonly due to cirrhosis. Herein, we describe the Doppler interrogation of a TIPS using intraoperative TEE, and how changes in the transmitted portal venous waveform were used to assess the severity of tricuspid regurgitation and inform management. (A&A Practice. 2022;16:e01607.).

Feasibility and Utility of the Venous Excess Ultrasound Score to Detect and Grade Central Venous Pressure Elevation in Critically Ill Children.

The Venous Excess Ultrasound (VExUS) score has been described as a useful tool to estimate the degree of venous congestion in adult patients. The present study aimed to analyze the feasibility and usefulness of the VExUS score to detect and grade central venous pressure (CVP) elevation in critically ill children. A cross-sectional pilot study was conducted in a tertiary-care pediatric intensive care unit between November 2020 and June 2021. All children in whom CVP was monitored, were enrolled. At the time of central venous catheter placement, CVP and VExUS score grade were determined, analyzing the inferior vena cava (IVC) diameter and the hepatic (HVD), portal (PVD), and intrarenal (IRVD) venous Doppler waveforms. A total of 33 children were studied (median age 12.2 [interquartile range (IQR) 4.1-100.6] months old; median weight 8.5 [IQR 5.6-35] kg; 20 [60.6%] males). The VExUS score was successfully obtained in 100% of the patients and its severity was strongly associated with the CVP levels (P< .001). Analyzing the VExUS score components separately, IVC dilation (P< .001) and severe HVD (P= .026), mild IRVD (P= .005), and severe IRVD (P= .025) patterns were associated with elevated CVP. After adjustment for confounding factors, IRVD pattern remained the only independent variable associated with elevated CVP. The VExUS score appears to be a feasible and potentially useful bedside noninvasive monitoring tool for the detection and grading of CVP elevation in critically ill children. Among all its components, IRVD assessment seems most associated with high CVP in this population.

Characterization of Doppler spectrum of hepatic veins in dogs with pulmonary hypertension

Pulmonary hypertension (PH) triggers hemodynamic changes within the right heart, which may affect hepatic venous flow. The aims of this study were three-fold: to investigate, prospectively, the reliability of the hepatic vein Doppler waveform to diagnose and characterize the magnitude of PH in dogs; to evaluate whether a correlation exists between hepatic venous flow waves and the structural and functional characteristics of the right ventricle (RV); and to determine whether age, gender, body weight, heart rate (HR), heart rhythm and systolic blood pressure affect the hepatic venous waveform pattern.A cross-sectional observational study was carried out in 43 dogs with varying degrees of PH and a control group of 15 healthy dogs. The velocities of the hepatic A, S, V and D spectral waves and the phasic pattern varied according to the severity of PH. Weak to moderate correlations were documented between hepatic vein waves and age, HR, and the structural and functional variables of the RV. A D Wave cut-off of 11.6 cm ∙ s-1 had a sensitivity of 100% and specificity of 35% for differentiation of dogs with severe PH from healthy dogs. Doppler assessment of hepatic venous flow was shown to be a reliable technique for screening dogs for PH.

Correlation between Hepatic Vein Wave form Changes on Doppler Ultrasound and the Severity of Diseases in Cirrhotic Patients

Background: Cirrhosis is a common problem and is a leading cause of chronic liver disease. Early diagnosis with assessment of severity of diseases may help prevent the associated complications and patients’ sufferings. Now a days Hepatic venous Doppler can be a tool for diagnosis of cirrhosis and to assess correlation between waveform changes and severity of diseases. Objective: The purposes of this study was to determine the significance of hepatic vein waveform changes on doppler ultrasound in cirrhotic patients and to correlate with liver dysfunction. Materials and methods: This study was carried out in the department of Radiology and Imaging of Enam Medical College and Hospital during January 2017 to May 2018. Doppler waveforms were obtained from right hepatic vein in all the cases and classified as triphasic, biphasic and monophasic. Waveform comparisons were made among patients with differing grades of cirrhosis. Child- Pugh class was used to assess severity of cirrhosis. Doppler sonography was done in 80 patients suspecting of having liver cirrhosis. Data on clinical findings, B mode sonographic findings and hepatic vein doppler ultrasound findings were collected and documented in structured forms. Analysis was done using SPSS - 20. Results: Total of 80 patients who met the inclusion criteria are included in the study with mean age of 45.37±7.64 (range 25-75) years. Among these 57 (71%) were males while 23(29%) were females. On the basis of hepatic function 25 (31%) patients presented in Child-Pugh Class A, 31(39%) with Class B and 24(30%) patients had Class C. Hepatic venous waveform was triphasic in 22 (27.5%), biphasic in 28(35%), and monophasic in 30 (37.5%) cases. Our study revealed 88% (21) of Child- Pugh Class C, 23% (7) of Class B and 8% (2) of class A patients had monophasic HV waveform. The hepatic venous waveform progressively changed from triphasic to biphasic to monophasic with advancing grade of cirrhosis. The relationship of these waveforms change had significant relation with hepatic dysfunction (p &lt; 0.022). Conclusion: Hepatic vein wave form changes reflects the change in hepatic circulation associated with progression of liver cirrhosis. It can be used as a new parameter in the assessment of severity of liver cirrhosis. Thus, alteration in hepatic venous blood flow pattern on doppler ultrasound can be a useful noninvasive tool for evaluating diseases severity in patients with cirrhosis. J MEDICINE 2021; 22: 100-106

Venous congestion assessment using point-of-care Doppler ultrasound: Welcome to the future of volume status assessment.

With evolution of clinician‐performed bedside ultrasonography, noninvasive markers of venous congestion such as hepatic, portal, and intrarenal venous Doppler waveforms are gaining importance as an adjunct to volume status assessment. The intent of this clinical image is to illustrate the classic sonographic stigmata of severe venous congestion, associated with worse prognosis.

Utility of Doppler Ultrasound-Derived Hepatic and Portal Venous Waveforms in the Management of Heart Failure Exacerbation

Utility of Doppler Ultrasound-Derived Hepatic and Portal Venous Waveforms in the Management of Heart Failure Exacerbation

Pulsed-wave Doppler ultrasonographic evaluation of hepatic vein in dogs with tricuspid regurgitation.

This study was performed to identify the relationships between hepatic vein (HV) measurements, including flow velocity and waveform, using pulsed-wave (PW) Doppler ultrasonography, and the severity of tricuspid regurgitation (TR) in dogs. The study included 22 dogs with TR and 7 healthy dogs. The TR group was subdivided into 3 groups according to TR jet profile obtained by echocardiography. The hepatic venous waveform was obtained and classified into 3 types. A variety of HV measurements, including the maximal velocities of the atrial systolic, systolic (S), end ventricular systolic, and diastolic (D) waves and the ratio of the S- and D- wave velocities (S/D ratio), were acquired. TR severity was significantly correlated with the S- (r = −0.380, p = 0.042) and D- (r = 0.468, p = 0.011) wave velocities and the S/D ratio (r = −0.747, p < 0.001). Receiver operating characteristic curve analysis revealed the highest sensitivity and specificity for the S/D ratio (89% and 75%, respectively) at a threshold of 0.97 with excellent accuracy (AUC = 0.911, p < 0.001). In conclusion, PW Doppler ultrasonography of the HV can be used to identify the presence of significant TR and to classify TR severity in dogs.

Hepatic Venous Waveform, Splenoportal and Damping Index in Liver Cirrhosis: Correlation with Child Pugh's Score and Oesophageal Varices.

Clinical assessment of chronic liver disease is done by Modified Child Pugh's and Model for end-stage liver disease scoring system. Measurement of hepatic venous pressure gradient (HVPG) and Upper GI Endoscopy are considered the gold standards for measurement of portal hypertension in cirrhotics. There is a need for non-invasive evaluation of portal hypertension. Ultrasonography with colour and spectral Doppler evaluation may be an effective, rapid and inexpensive alternative. To evaluate hepatic venous waveform, damping index, splenoportal index in patients of cirrhosis on Colour Doppler ultrasound, also predict severity of portal hypertension and presence of oesophageal varices. Thirty patients of chronic liver disease were included in the study. Ultrasound and colour Doppler was done to look hepatic venous waveform pattern, Damping Index (DI), and Splenoportal Index (SPI). Contrast-enhanced Computed Tomography scan (CT) was done if renal function tests were normal, else endoscopy when the renal function tests were deranged to look for oesophageal varices. Twenty two (73.3%) patients had monophasic waveform. Biphasic and triphasic waveforms were seen in 4 (13.3%) cases. Twenty two patients (73.3%) had monophasic waveforms and majority of them were in class C. This distribution of hepatic vein waveform was statistically significantly with the Child Pugh's class (p<0.05). Twenty patients (66.7%) had value of Damping index more than >0.6 where majority of patients (18) belonged to class C and 2 in class B. There was a positive correlation between Child Pugh's total score and Damping index (r=0.614; p<0.05). There was weak positive correlation between splenoportal index and Child Pugh's score (r=0.269; p=0.15). Change in triphasic to monophasic waveform and DI >0.6 suggests severe liver dysfunction and is associated with severe portal hypertension. Hepatic venous waveform pressure changes, DI and SPI have no value in predicting presence of oesophageal varices.

Usefulness of B-mode and doppler sonography for the diagnosis of severe acute viral hepatitis A.

To investigate B-mode and Doppler ultrasonography (US) features correlating with laboratory findings for the diagnosis of severe acute hepatitis (SAH) in patients with hepatitis A virus infection. Thirty-nine consecutive serologically proven patients were enrolled. Decreased parenchymal echotexture, periportal tracking, gallbladder wall change, and splenomegaly were assessed on B-mode images. Blood flow velocities were measured in the main portal (V(PORTAL)) and in the hepatic veins, and the hepatic venous pulsatility index was calculated. SAH was defined as high model for end-stage liver disease (MELD) score ≥ 15 with or without coagulopathy. The relationship between US features and laboratory findings was assessed, and SAH diagnosis was evaluated. Serum alanine transaminase and prothrombin time were significantly different depending on the presence of gallbladder wall change and splenomegaly (p < 0.05). V(PORTAL) was inversely correlated with MELD score (r = -0.485) and several laboratory markers. The hepatic venous waveform and hepatic venous pulsatility index were significantly correlated with MELD score. For the diagnosis of SAH, the area under the receiver operating characteristic curve of V(PORTAL) was 0.798. It reached 0.869 in the patients with typical GB change. Both B-mode and Doppler US correlated well with several laboratory variables and may be helpful to diagnose SAH in patients with hepatitis A virus infection.

Doppler ultrasound velocities and resistive indexes immediately after pediatric liver transplantation: normal ranges and predictors of failure.

We sought to determine the ranges of Doppler ultrasound findings immediately after pediatric liver transplantation that are associated with successful outcomes or postoperative complications. This study included consecutive children who underwent Doppler ultrasound less than 48 hours after liver transplantation from 2001 to 2011. Operative reports and clinical outcome data were recorded. We had 110 patients (54% girls) with mean age at transplantation of 2.9 years (median, 1.3 years; range, 0-14 years) and a median follow-up interval of 3.5 years. Two pediatric radiologists reviewed ultrasound images in consensus. We computed descriptive statistics, interindex correlations, and analysis of variance. Twenty-four of 110 patients had a vascular complication, most commonly hepatic arterial thrombosis (seven patients). Compared with published adult normal values, normal pediatric Doppler parameters at postoperative day 1 trended toward higher normal velocities and resistive indexes (up to 0.95). Absent or low-velocity common hepatic artery flow less than 50 cm/s or a common hepatic artery resistive index less than 0.50 were significantly associated with hepatic artery thrombosis, whereas absent or low-velocity portal venous flow less than 30 cm/s or low-velocity hepatic venous flow less than 25 cm/s were significantly associated with vascular complications and a monotonic hepatic venous waveform was significantly associated with venous complications. Flow in a pediatric liver on the first day after transplantation is normally hyperdynamic, especially in the youngest transplant recipients, and, as a result, low velocities or resistive indexes are particularly concerning for complications. The pediatric-specific ranges of expected posttransplantation Doppler ultrasound findings presented in this article should assist in identifying normal variation and potentially life-threatening complications.

Hemodynamic Changes of Hepatic Veins as Predictors of Large Oesophageal Varices in Liver Cirrhotic Patients

Background and study aim: Oesophageal varices (OV) are morbid and mortal complications of portal hypertension. Oesophago-gastroduodenoscopy (OGD) is the main diagnostic yet semi- invasive tool; different non-invasive methods were developed for early prediction and assessment of OV yet not fully evaluated. This work aims at assessment of changes of hepatic venous wave patterns as early predictors of large OV in cirrhotic patients without history of variceal bleeding. Patients and methods: A number of 50 previously diagnosed liver cirrhotic patients were subjected to detailed history taking. After exclusion criteria only 46 patients were included in the study. They were subjected to routine investigations, OGD, abdominal ultrasound (US) and Color Doppler studying of the hepatic veins (HV). Results : Out of the total number (46 liver cirrhotic patients included in the study), the triphasic waves were detected in (26.1%), biphasic waves in (43.5%) and monophasic waves in (30.4 %). Small varices were detected in (65.2 %), while large varices were detected in (34.8 %).The sensitivity of loss of the triphasic waveform in detecting large varices was high (93.8 %), specificity was (36.7 %), the positive predictive value was (44.1 %) and the negative predictive value was high (91.7 %). Conclusion : The loss of hepatic venous triphasic waveform - detected by Color Doppler Abdominal Ultrasound Study- is a weak predictor of large OV in liver cirrhotic patients without history of variceal bleeding

A comparative study of Duplex Doppler ultrasound and blood indices as noninvasive predictors of oesophageal varices in cirrhotic patients

BackgroundEndoscopic surveillance of oesophageal varices (OV) in cirrhotic patients is expensive and uncomfortable for the patients. Therefore, there is a particular need for noninvasive predictors for OV.ObjectiveThe aim of the present study was to evaluate the accuracy of ultrasound indices and blood indices as noninvasive OV predictors among cirrhotic patients.Patients and methodsA total of 61 cirrhotic patients were enrolled in this study and were divided into two groups: 21 patients without OV and 40 patients with OV who were further subdivided into 24 patients with small OV and 16 with large oesophageal varices (LOV). P2/MS, serum fibrosis markers (APRI, FIB4, Lok score, and Forns index), abdominal ultrasonography [portal vein diameter (PVD), splenic index], platelet count/spleen diameter ratio (PC/SD), and Doppler ultrasonography [portal vein velocity, splenoportal index, hepatic and splenic impedance indices, and hepatic venous waveform (HVWF)] were assessed in all patients.ResultsP2/MS was the best predictor of OV and LOV [area under the curve (AUC) 0.88 and 0.787, respectively] followed by PC/SD (AUC 0.77 and 0.715, respectively). PVD, serum fibrosis markers, and serum albumin had the least accuracy for OV prediction. For LOV predictions, Lok score had good accuracy (AUC 0.785) followed by serum albumin, PVD, APRI, and Forns index (AUC 0.72, 0.738, 0.734, and 0.738, respectively). Monophasic HVWF showed a good positive predictive value (85%) and specificity (80.95%) for prediction of OV and good sensitivity (81.25%) and negative predictive value (81.25%) for LOV.ConclusionP2/MS can identify OV and LOV in cirrhosis with high accuracy followed by PC/SD. Monophasic HVWF is a good noninvasive predictor of OV and LOV in cirrhotic patients.

Non-invasive ultrasound-based diagnosis and staging of esophageal varices in liver cirrhosis. A systematic review of the literature published in the third Millenium

Endoscopic surveilance of esophageal varices in patients with liver cirrhosis is expensive for the health system and uncomfortable for the patients. Recently, non-invasive ultrasound-based parameters seem to offer valuable informations about the status of esophaeal varices and thus challenge the need for repetitive endoscopic monitoring. We have performed a systematic review of the literature published in PubMed from January 2000 until March 2012 over the role of ultrasound-based parameters on the evaluation of esophageal varices in patients with liver cirrhosis. Eleven papers studied the role of gray-scale and Doppler ultrasound and two further studies analyzed the relationship between liver stiffness and staging of esophageal varices. The parameters that proved to be valuable for diagnosis of esophageal varices and reached statistcal significance were: diameter of the spleen > 15 cm, congestion index of the portal vein > 0.154 cm x sec, portal hipertensive index > 2.08, liver stiffness > 43.97kPa, portal vein diameter > 13 mm, renal artery resistance index >/= 0.7 and development of new porto-systemic collaterals. Other parameters such as: pattern of hepatic venous waveforms or flow parameters of the hepatic or splenic veins did not reach statistical significance. Altough esophagogastroduodenoscopy remains the golden standard, there are some ultrasound-based parameters which, used within complex algorithms, may represent a viable alternative for the diagnosis and surveilance of esophageal varices in patients with liver cirrhosis.

The Prediction of Liver Disease Status Using a Combination of Sonographic and Doppler-Derived Observations of the Portal Venous System

A novel diagnostic test, named the PREW© score, was formulated to predict the known liver disease status of a purposive sample of 500 patients (304 cases and 196 controls) referred for abdominal sonograms. The score was defined by (P R E)/W, where P = portal vein pressure gradient (mm Hg), R = ratio between the observed mean portal vein diameter in the patient (mm) and the mean diameter in healthy subjects (mm), E = echogenicity of liver parenchyma (ECHO grade scale), and W = hepatic venous waveform (1 = monophasic to 3 = triphasic). Cases with PREW scores &gt;50 were about 480 times more likely than the controls to be diagnosed with cirrhosis/ascites. Cases with PREW scores of 16 to 50 were about 6 to 15 times more likely than the controls to be diagnosed with hepatitis and about 15 to 120 times more likely to be diagnosed with cirrhosis/ascites. It was not possible to clearly discriminate between a diagnosis of hepatitis and cirrhosis/ascites if the PREW score was less than 50. The likelihoods of patients with PREW scores &gt;25 being diagnosed with nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) or gallbladder (GB) disease were not statistically significant. A PREW score greater than 25 identified cases diagnosed with hepatitis/cirrhosis/ascites but eliminated diagnoses of NAFLD/NASH/GB. The clinical implication is that a PREW score &gt;50 may help to facilitate the diagnosis of cirrhosis without confirmation by liver biopsy.

A Case-Control Study to Compare the Likelihood of Detecting Liver Disorders Using Coincident Measures of Doppler-Derived Portal Vein Pressure Gradients, Hepatic Venous Waveforms, and the Echogenicity of Liver Parenchyma

A case-control study based on the records of 465 adult patients receiving abdominal sonograms predicted the likelihood of liver damage, as detected by serum biomarkers, biopsy, and/or endoscopy, to increase systematically with respect to (a) an increase in echogenicity from grade 1 (odds ratio [OR] = 2.94) through 2 (OR = 10.50) to 3 (OR = 14.91) coincident with (b) a dampening of the hepatic venous waveform (HVW) from biphasic (OR = 1.66) to monophasic (OR = 3.68) and (c) a simultaneous elevation in the portal vein pressure gradient, adjusted for portal vein diameter (PVPG) from level 1 (OR = 1.85) through 2 (OR = 3.23) to 3 (OR = 3.35). Echogenicity consistently exhibited higher sensitivities but lower specificities than the HVW and PVPG. The lowest specificities were found among patients with a body mass index &gt;25, proposed to be associated with intrahepatic fat infiltration causing false positives in the absence of hepatopathology.

Doppler assessment of hepatic venous waves for predicting large varices in cirrhotic patients

Background/Aim:Color Doppler examination of changes in hepatic venous waveforms is being evaluated as a means of prediction of severity of portal hypertension and presence of esophageal varices. Normal hepatic venous waveform shows a triphasic pattern. In cirrhosis, this pattern changes to a biphasic or monophasic pattern. We aimed to study the sensitivity of loss of normal hepatic venous waveforms in predicting large varices in a cross-sectional analysis.Materials and Methods:All patients, admitted or attending the outpatient department, with a diagnosis of cirrhosis were included in the study. All patients were subjected to oesophagogastroduodenoscopy and Color Doppler examination, and waveform patterns in hepatic vein were recorded. The sensitivity and specificity of changes in waveform in detecting large varices were studied.Results:A total of 51 cases were examined. Triphasic waves were seen in 4 (7.8%) cases, biphasic in 26 (51%) cases, and monophasic in 21 (41.2%) cases. Small varices were seen in 30 (58.8%) cases and large varices in 21 (41.2%) cases. The sensitivity of loss of the triphasic wave pattern in detecting significant varices (Grade 3 or 4) was very high (95.23%) and negative predictive value was also high (75%). Severity of liver disease as indicated by Child-Pugh and MELD scores did not correlate with changes in hepatic venous waveforms.Conclusion:Loss of triphasic hepatic venous waveform is highly sensitive in predicting significant varices in patients with cirrhosis.

Effects of respiratory manoeuvres on hepatic vein Doppler waveform and flow velocities in a healthy population

Objective This study was performed to determine the variations in Doppler waveforms and flow velocity during respiratory manoeuvres in healthy individuals with no liver disease. Materials and methods In total, 100 individuals (75 women and 25 men) without known cardiac or liver disease were examined prospectively with duplex Doppler ultrasonography (US). We recorded the Doppler waveforms and peak systolic velocities ( V max) of the middle hepatic vein during normal respiration, during breath-holding after quiet expiration and also during deep inspiration. Doppler waveforms are categorised as triphasic, biphasic or monophasic. Results During normal respiration, hepatic venous waveforms were triphasic in 93% of subjects, monophasic in 6% and biphasic in 1%. During breath-holding after quiet expiration, the percentages were 91%, 6% and 3%, respectively. During deep inspiration, they were 80%, 18% and 2%, respectively. Although significant differences were noted between rates during deep inspiration and normal respiration, they were quite similar during normal respiration and breath-holding after quiet expiration ( P < 0.05). The values of V max were significantly higher during normal respiration compared to quiet expiration and during quiet expiration compared to deep inspiration ( P < 0.05). Conclusion The velocities and waveforms of hepatic veins varied during respiratory manoeuvres. The status of respiration must be taken into consideration whilst examining the hepatic vein waveforms and velocities with duplex Doppler US.

Noninvasive Assessment of Portal Hypertension–Can US Aid in the Prediction of Portal Pressure and Monitoring of Therapy?

A method that could be used to accurately assess portal venous pressure would be valuable when diagnosing portal hypertension, evaluating patient prognosis, and monitoring the progress of therapy. Baik et al have suggested that a qualitative noninvasive Doppler US parameter can be used to monitor therapy of portal hypertension. Further clinical investigation is needed to confirm these results and to determine whether hepatic venous Doppler waveform tracings can be used to monitor patient response to therapy. Ongoing research suggests that microbubble contrast agents may enable a more quantitative noninvasive estimate of intravascular pressures with US.

Doppler waveform of the hepatic veins in an obese population

The objective is to investigate the effect of obesity and hepatosteatosis on the Doppler waveform pattern of the hepatic veins. B-mode and duplex Doppler sonography of the liver and the right hepatic vein was performed in 102 obese subjects and 84 healthy volunteers. The severity of fatty infiltration was graded as mild, moderate and severe. The flow pattern of the right hepatic vein was classified as triphasic, biphasic and monophasic. The Doppler flow pattern in the right hepatic vein was triphasic in 56 (55%), biphasic in 27 (26%) and monophasic in 19 (19%) obese patients, whereas it was triphasic in 83 (99%) and biphasic in 1 (1%) control subject, achieving a statistical significance (Mann-Whitney U-test, P<0.001). There was an inverse correlation between the sonographic grade of the hepatosteatosis and the phasicity of hepatic venous flow (r=-0.67, P<0.001). The hepatic vein pulsatility is significantly dampened in obese patients correlating with the grade of hepatosteatosis. The body habitus itself does not have an independent effect on hepatic venous waveform. The alteration in hepatic vein Doppler flow pattern in an obese population may suggest reduced vascular compliance in the liver because of fatty infiltration.

Hepatic venous Doppler waveforms: changes in pregnancy.

A total of 75 fasted healthy normal volunteers were examined during various stages of pregnancy. Examinations were performed in a supine position using an Acuson 128 ultrasound scanner with a 3.5 MHz transducer. Doppler interrogation of the middle hepatic vein was made during quiet respiration by one of three examiners. The Doppler waveforms were subsequently assessed blindly by one of the authors and categorized as normal, damped, or flat. Between 12 and 20 weeks, the majority of patients had normal hepatic pulsatility (64%) with 20% damped and 16% flat. Between 20 and 30 weeks there was a significant change (p > 0.001) with 68% being flat, 20% damped, and only 12% normal. In the last 10 weeks of pregnancy the changes were more marked: 80% were flat, 12% dampened, and 8% normal. There was a profound change in hepatic venous pulsatility during pregnancy. Hepatic waveforms changed from their normal pulsatile nature to become completely flat with increasing gestation. These changes were more frequent and more marked the further gestation progressed.