Liver cirrhosis: changes of Doppler waveform of hepatic veins

Prediction of Esophageal Varices in Viral Hepatitis C Cirrhosis: Performance of Combined Ultrasonography and Clinical Predictors

Objectives

This study is aimed at evaluating the diagnostic performance of clinical predictors and the Doppler ultrasonography in predicting esophageal varices (EV) in patients with hepatitis C-related cirrhosis and exploring the practical predictors of EV.

Methods

We conducted a prospective study from July 2020 to January 2021, enrolling 65 patients with mild hepatitis C-related cirrhosis. We obtained clinical data and performed grayscale and the Doppler ultrasound to explore the predictors of EV. Esophagogastroduodenoscopy (EGD) was performed as the reference test by the gastroenterologist within a week.

Results

The prevalence of EV in the study was 41.5%. Multivariable regression analysis revealed that gender (female, OR = 4.04, p = 0.02), platelet count (<150000 per ml, OR = 3.13, p = 0.09), splenic length (>11 cm, OR = 3.64, p = 0.02), and absent right hepatic vein (RHV) triphasicity (OR = 3.15, p = 0.03) were significant predictors of EV. However, the diagnostic accuracy indices for isolated predictors were not good (AUROC = 0.63-0.66). A combination of these four predictors increases the diagnostic accuracy in predicting the presence of EV (AUROC = 0.80, 95% CI 0.69-0.91). Furthermore, the Doppler assessment of the right hepatic vein waveform showed good reproducibility (κ = 0.76).

Conclusion

Combining clinical and Doppler ultrasound features can be used as a screening test for predicting the presence of EV in patients with hepatitis C-related cirrhosis. The practical predictors identified in this study could serve as an alternative to invasive EGD in EV diagnosis. Further studies are needed to explore the diagnostic accuracy of additional noninvasive predictors, such as elastography, to improve EV screening.

Hepatic Venous Stasis Index Reflects Hepatic Congestion and Predicts Adverse Outcomes in Patients With Heart Failure

Background It has been reported that the hepatic vein waveforms determined by abdominal ultrasonography can assess hepatic congestion in patients with heart failure (HF). However, the parameter that quantifies hepatic vein waveforms has not been established. We suggest the hepatic venous stasis index (HVSI) as the novel indicator to evaluate hepatic congestion quantitatively. To examine the clinical significance of HVSI in patients with HF, we aimed to clarify the associations of HVSI with the parameters of cardiac function and right heart catheterization, as well as that with prognosis, in patients with HF. Methods and Results We performed abdominal ultrasonography, echocardiography, and right heart catheterization in patients with HF (n=513). The patients were divided into 3 groups based on HVSI as follows: HVSI 0 (HVSI=0, n=253), low HVSI (HVSI 0.01-0.20, n=132), and high HVSI (HVSI>0.20, n=128). We examined the associations of HVSI with parameters of cardiac function and right heart catheterization and followed up for cardiac events defined as cardiac death or worsening HF. There was a significant increase in level of B-type natriuretic peptide, inferior vena cava diameter, and mean right atrial pressure with increasing HVSI. During the follow-up period, cardiac events occurred in 87 patients. In the Kaplan-Meier analysis, cardiac event rate increased across increasing HVSI (log-rank, P=0.002). Conclusions HVSI assessed by abdominal ultrasonography reflects hepatic congestion and right-sided HF and is associated with adverse prognosis in patients with HF.

Application of ultrasound for the diagnosis of cirrhosis/portal hypertension

With advances in technologic approaches in patients with cirrhosis, including the improvement of management, a simple, one-step approach for advanced fibrotic state of the liver is clinically useful. Although refining the diagnosis of cirrhosis to reflect disease heterogeneity is essential, current diagnostic tests have not kept pace with the progression of this new paradigm. There are unmet needs in primary care centers with respect to patients with cirrhosis. Liver biopsy and measurement of hepatic venous pressure gradient in patients with cirrhosis are the gold standards for the estimation of hepatic fibrosis, and they have diagnostic and prognostic value. However, both approaches are invasive and cannot be used repeatedly in clinical practice. Ultrasonography (US) is safe, easy to perform, inexpensive, and yields numerical and accurate results. Conventionally, the size of the liver and spleen, bluntness of the liver edge, nodularity of the liver surface, and coarseness of the liver parenchyma have been known as useful parameters for hepatic fibrosis or portal hypertension (PHT) in chronic liver disease. Additionally, some functional US indices including Doppler and CEUS-based examination have been suggested as promising markers for diagnosing cirrhosis and PHT. Identification of the reproducibility and long-term prognostic value through further investigations can demonstrate the clinical usefulness of functional US indices, which are characterized as quantitative parameters for hepatic fibrosis and PHT.

Hepatic function predictive value of hepatic venous waveform versus portal vein velocity in liver cirrhosis

Background:

This study assessed the hepatic vein waveform (HVW) and mean maximum portal vein velocity (MM-PVV) on Doppler ultrasound in patients with liver cirrhosis (LC) and compared it with that of age and sex-matched controls. It correlated the degree of HVW abnormality and MM-PVV changes with liver function based on Child-Turcotte-Pugh (CTP) to determine which was more predictive of CTP.

Methods:

Sixty patients with LC and 60 healthy controls were consecutively recruited into this study. Each patient was classed based on the CTP system after relevant tests. Doppler evaluation of the hepatic vein (HV) and MM-PVV were performed. HVW obtained was classified either into triphasic, biphasic, or monophasic.

Results:

Sixty cirrhotic and 60 age-matched control subjects aged 19–69 and 18–69 years, respectively, completed this study. All control subjects had a normal HVW pattern while 46 (76.7%) cirrhotic subjects had abnormal HVW (P < 0.001). The MM-PVV was significantly lower in cirrhotic subjects than in controls; 22.8 cm/s versus 33.6 cm/s (P < 0.001). The degree of HVW abnormality among cirrhotics showed a significant positive correlation with CTP (r = 0.283, P = 0.029). MM-PVV on the other hand showed no correlation with CTP class (r = −0.124; P = 0.346). Linear regression showed that HVW was a significant predictor of hepatic dysfunction based on CTP.

Conclusion:

Changes in the waveform pattern of the HVs are a good predictor of the derangement of hepatic function in patients with LC than changes in PVV. HVW pattern could therefore serve as an adjunct to CTP class in hepatic function assessment.

Conventional ultrasound for diagnosis of hepatic steatosis is better than believed

BACKGROUND

Hepatic steatosis is a condition frequently encountered in clinical practice, with potential progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. Detection and staging of hepatic steatosis are of most importance in nonalcoholic fatty liver disease (NAFLD), a disease with a high prevalence of more than 1 billion individuals affected. Ultrasound (US) is one of the most used noninvasive imaging techniques used in the diagnosis of hepatic steatosis. Detection of hepatic steatosis with US relies on several conventional US parameters, which will be described. US is the first-choice imaging in adults at risk for hepatic steatosis. The use of some scoring systems may add additional accuracy especially in assessing the severity of hepatic steatosis.

SUMMARY

In the presented paper, we discuss screening and risk stratification, ultrasound features for diagnosing hepatic steatosis, B-mode criteria, focal fatty patterns and Doppler features of the hepatic vessels, and the value of the different US signs for the diagnosis of liver steatosis including classifying the severity of steatosis using different US scores. Limitations of conventional B-mode and Doppler features in the evaluation of hepatic steatosis are also discussed, including those in grading and assessing the complications of steatosis, namely fibrosis and nonalcoholic steatohepatitis.

KEY MESSAGES

Ultrasound is the first-line imaging examination for the screening and follow-up of patients with liver steatosis. The use of some scoring systems may add additional accuracy in assessing the severity of steatosis. Conventional B-mode and Doppler ultrasound have limitations in grading and assessing the complications of steatosis.

Liver Congestion Assessed by Hepatic Vein Waveforms in Patients With Heart Failure

Background

It has been reported that the pattern of hepatic vein (HV) waveforms determined by abdominal ultrasonography is useful for the diagnosis of hepatic fibrosis in patients with chronic liver disease. We aim to clarify the clinical implications of HV waveform patterns in patients with heart failure (HF).

Methods

We measured HV waveforms in 350 HF patients, who were then classified into 3 categories based on their waveforms: those with a continuous pattern (C group); those whose V wave ran under the baseline (U group), and those with a reversed V wave (R group). We performed right-heart catheterization, and examined the rate of postdischarge cardiac events, such as cardiac death and rehospitalization due to worsening HF.

Results

The number of patients in each of the 3 HV waveform groups was as follows: C group, n = 158; U group, n = 152, and R group, n = 40. The levels of B-type natriuretic peptide (R vs C and U; 245.8 vs 111.7 and 216.6 pg/mL; P < 0.01) and mean right atrial pressure (10.5 vs 6.7 and 7.2 mm Hg; P < 0.01) were highest in the R group compared with the other groups. The Kaplan-Meier analysis found that cardiac event–free rates were lowest in the R group among all groups (log-rank P < 0.001). In the multivariable Cox proportional hazard analysis, the R group was found to be an independent predictor of cardiac events (hazard ratio, 4.90; 95% confidence interval, 2.23-10.74; P < 0.01).

Conclusion

Among HF patients, those with reversed V waves had higher right atrial pressure and were at higher risk of adverse prognosis.

The Echogenic Liver: Steatosis and Beyond

ABSTRACT

Ultrasound is the most common modality used to evaluate the liver. An echogenic liver is defined as increased echogenicity of the liver parenchyma compared with the renal cortex. The prevalence of echogenic liver is approximately 13% to 20%. In most clinical settings, increased liver echogenicity is simply attributed to hepatic steatosis. It is important to recognize other hepatic and systemic diseases including cirrhosis, viral hepatitis, glycogen storage disease, and hemochromatosis that may also cause an echogenic liver and to identify the associated findings to distinguish them from hepatic steatosis.

Portal hypertension evolving from sickled hepatopathy: Could hepatic venous Doppler ultrasound be beneficial in its evaluation?

PURPOSE

Sickle cell intrahepatic cholestasis involves sickling within hepatic sinusoids leading to vascular stasis and localized hypoxia resulting in ballooning of the hepatocytes causing a direct back pressure effect with resultant intracanalicular cholestasis. Vascular stasis may ultimately lead to portal hypertension. We proposed to document findings suggestive of portal hypertension evolving from hepatopathy in steady-state sickle cell disease (SCD) patients using hepatic venous Doppler ultrasound.

METHODS

This is a prospective case series of 6 SCD subjects in steady-state (median age, 30 years; range, 19-43), comprising of 3 males and 3 females, who underwent a routine Doppler ultrasound evaluation of their hepatic veins and were discovered to have an abnormal biphasic waveform pattern. Venous blood was obtained from all subjects to evaluate for P-selectin, homocysteine, foetal haemoglobin, haematocrit levels, white cell and platelet counts. Doppler ultrasound was also carried out on all subjects to evaluate for the hepatic waveform, right renal artery RI and PI along with the hepatic artery velocities.

RESULTS

All the 6 subjects had reduced haematocrit (median value of 21.5%; range, 18-25%) and some degree of renal dysfunction (plasma cystatin-C ranged from 1.6 to 12.2 mg/L). Elevated white cell count, hyperhomocysteinemia, reduced SpO₂(<94.0%) and reduced estimated GFR (eGFR < 90 ml/min) was also noted in 4 subjects (66.7%). Similarly, 4 subjects (66.7%) had elevated RI in the right kidneys while 3 subjects (50.0%) had elevated PI in the right kidney.

CONCLUSION

Doppler ultrasound Hepatic vein waveform analysis may be a useful examination in the evaluation of patients with SCD as it may elicit feature of portal hypertension. Further studies are suggested to confirm this in a larger population of SCD patients using the gold standard.

Utility of hepatic vein waveform and transient elastography in patients with Budd-Chiari syndrome who require angioplasty: Two case reports

RATIONALE

Budd-Chiari syndrome (BCS), which causes congestive hepatopathy and aggravates cirrhosis, is typically treated by interventional angioplasty to ameliorate blood flow. X-ray venography is useful for the evaluation of inferior vena cava (IVC) stenosis and determination of treatment timing, but it is invasive and thus unsuitable for repeated examinations. The development of a simple method for the prediction of IVC stenosis would reduce the burden on patients with BCS.

PATIENT CONCERNS

We report here our experience of 2 patients with BCS who underwent percutaneous transluminal angioplasty (PTA). The first patient was a 39-year-old male who underwent PTA to expand his stenotic IVC. The second patient was a 19-year-old male who underwent PTA 3 times due to restenosis of his IVC.

DIAGNOSES

Both patients were diagnosed with BCS with severe obstruction of the IVC.

INTERVENTIONS

We evaluated the hepatic vein (HV) waveform by Doppler ultrasonography and measured liver stiffness (LS) using transient elastography (TE) before and after PTA.

OUTCOMES

In case 1, the phasic oscillation of the HV waveform recovered and the LS value decreased after PTA. Both improvements were maintained for ∼3 years, reflecting the long-term patency of the IVC. In case 2, the HV waveform and the LS value improved temporarily after PTA, but then deteriorated gradually. Monitoring of the HV waveform and LS value allowed retreatment prior to total occlusion of the IVC and abrogated the risk of intravascular needle puncture.

LESSONS

Monitoring of the HV waveform and the LS value enables safe management of patients with BCS who may require PTA.

A Novel Non-invasive Method for Predicting Liver Fibrosis by Quantifying the Hepatic Vein Waveform

The hepatic vein (HV) waveform by Doppler ultrasound reflects the severity of liver fibrosis. We conducted a proof-of-concept study of a new method for quantifying the HV waveform. We calculated the coefficient of variation (CV) of the HV flow velocity and created a new index "q-HV" (quantified HV) and analyzed its performance for predicting histologic liver fibrosis in 114 patients with chronic liver disease. The CV of the HV flow velocity was well associated with flattening of the waveform and the q-HV significantly increased with the progression of liver fibrosis. The areas under the curve for the prediction of fibrosis stage were 0.732 for F2, 0.772 for F3 and 0.805 for F4. Combined q-HV and FIB-4 index (widely used liver fibrosis score) increased the diagnostic accuracy for liver fibrosis. The q-HV showed good accuracy for predicting liver fibrosis; thus, q-HV is feasible and acceptable as a non-invasive tool for predicting liver fibrosis.

Evaluation of portal hypertension in the cirrhotic patient: hepatic vein pressure gradient and beyond

Portal hypertension (PH) is a major complication of liver cirrhosis, as it predisposes to the development of serious clinical manifestations such as ascites, hepatic encephalopathy and variceal bleeding. Till now, the measurement of hepatic vein pressure gradient (HVPG) is the gold standard method to ascertain the presence and significance of PH, as many studies have shown its correlation with the appearance of varices and the possibility of variceal bleeding. However, the invasiveness of this procedure makes it difficult to be used in daily clinical practice. Several noninvasive methods with adequate capability of evaluating liver fibrosis, including elastographic techniques, are currently used as alternatives to HVPG in order to assess the presence and the severity of PH. The aim of this paper is to express an overview of the literature about the actual role of HVPG and all available noninvasive tests on the prediction of development of PH complications, to highlight their advantages and their potential limitations, and to provide the latest trends on clinical practice.

Identification of liver fibrosis using the hepatic vein waveform in patients with Fontan circulation

AIM

Liver fibrosis caused by congestive hepatopathy has emerged as an important complication after Fontan procedure. We evaluated the utility of the hepatic vein (HV) waveform using Doppler ultrasound for identification of liver fibrosis in Fontan patients.

METHODS

We investigated the HV waveforms in 41 Fontan patients and assessed correlations with clinical parameters, liver fibrosis markers, and hemodynamic data.

RESULTS

Based on our preliminary analysis of 64 adult patients with chronic liver disease who underwent liver biopsy, we classified HV waveforms into five types with reference to the degree of flattening (from type 1, normal triphasic waveform; to type 5, a monophasic waveform indicating cirrhosis), and confirmed a significant correlation between waveform pattern and fibrosis stage. Notably, we detected HV waveforms in all of the Fontan patients and classified them into five types. The HV waveform pattern positively correlated with γ-glutamyl transferase and hyaluronic acid levels, and negatively correlated with albumin level and platelet count, but did not correlate with central venous pressure or brain natriuretic peptide level, suggesting that HV waveform could reflect pathophysiological changes in the liver without being affected by hepatic congestion. The highest area under the receiver operating characteristic curve of the HV waveform for detecting advanced liver fibrosis, as defined by ultrasonic findings and clinical features, was 0.829 (81.8% sensitivity, 73.3% specificity), which was higher than that of other non-invasive fibrosis markers.

CONCLUSIONS

Hepatic vein waveforms change in accordance with liver fibrosis progression in Fontan patients, and can be a useful indicator of liver fibrosis after the Fontan procedure.

Doppler ultrasonography devices, including elastography, allow for accurate diagnosis of severe liver fibrosis

OBJECTIVES

Advanced chronic liver disease is frequent yet largely underdiagnosed. Doppler-US is a common examination and we recently identified three simple Doppler-US signs associated with severe liver fibrosis. Recent Doppler-US devices include elastography modules, allowing for liver stiffness measurement (LSM). Our aim was to assess whether the use of elastography following positive simple Doppler-US signs improves the detection of severe liver fibrosis in a single Doppler-US examination.

METHODS

514 patients with chronic liver disease who consecutively underwent percutaneous liver biopsy were included in the study. All patients had a Doppler-US examination and LSM with Virtual Touch Quantification (VTQ) on the same day as a liver biopsy. A subset of 326 patients also had LSM with 2D shear wave elastography (SSI). Severe fibrosis was defined as Metavir F ≥ 3 on liver biopsy.

RESULTS

Multivariate analysis confirmed our three simple Doppler-US signs (liver surface irregularity, splenomegaly ≥110 mm, and demodulation of hepatic veins) as independently associated with severe fibrosis. The presence of at least one of these three signs showed 85.6% sensitivity and 36.1% specificity for the diagnosis of severe liver fibrosis. Using VTQ (≥1.59 m/s) where there was a positive Doppler-US sign increased the specificity to 80.8%, at the cost of a decrease in sensitivity (73.7%). Similar results were obtained with SSI (≥9.5 kPa), with 73.3% specificity and 81.5% sensitivity.

CONCLUSION

Elastography improves the accuracy of Doppler-US in the detection of severe fibrosis. This two-step procedure will help radiologists to accurately identify patients who need to be referred to specialist hepatologists during routine Doppler-US examinations.

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.

Combining routine markers improves the accuracy of transient elastography for hepatitis B cirrhosis detection

BACKGROUND AND AIM

Vibration Controlled Transient Elastography (VCTE) is a non-invasive test for liver fibrosis and cirrhosis but may be inaccurate in some patients, especially in those with chronic hepatitis B. This study aims at improving the accuracy of VCTE in cirrhosis detection by combining ultrasound and routine blood parameters.

METHODS

Hepatitis B patients with liver biopsies samples ≥20mm underwent VCTE, ultrasound and blood tests, and were divided into training set (n=170) and validation set (n=75).

RESULTS

An algorithm consisting of VCTE, international normalization ratio (INR), ultrasonic hepatic vessel and platelet count (CIR-4) and a VCTE-based cirrhosis six-index score (CIR-6) comprised VCTE, INR, platelet, albumin, ultrasonic hepatic vessel and liver parenchyma were derived. In training set, area under receiver operating characteristics curve of CIR-6 and CIR-4 to detect cirrhosis was 0.946 and 0.945, respectively, which was superior to that of VCTE 0.907. CIR-4 could save more liver biopsies. In validation set, CIR-6 detected cirrhosis with accuracy similar to that in training set. However, the sensitivity of CIR-4 and VCTE in validation set lowered to 0.538 and 0.846, respectively.

CONCLUSIONS

Combining routine markers improve the accuracy of VCTE for cirrhosis detection in hepatitis B patients. CIR-6 may be more valuable.

Doppler Ultrasound and Transient Elastography in Liver Transplant Patients for Noninvasive Evaluation of Liver Fibrosis in Comparison with Histology: A Prospective Observational Study

BACKGROUND AND AIM

Accurate quantification of progressive liver disease is essential for therapeutic decisions and follow-up for patients who underwent liver transplantation. To evaluate the quality of noninvasive assessment of liver fibrosis in these patients, we compared Doppler ultrasound of the hepatic blood vessels as well as transient elastography (TE, FibroScan(®)) with liver biopsy following transplantation.

METHODS

We performed Doppler ultrasound of the hepatic veins, hepatic artery, and portal vein as well as a TE in 48 patients who underwent liver transplantation 12 months ago. Hepatic venous flow was evaluated by determination of the resistance index (HVRI) of the right hepatic vein. Doppler and TE results were compared with histopathologic workup of a 12-month protocol liver biopsy after transplantation.

RESULTS

HVRI showed a high reliability in predicting liver fibrosis stage FII or higher (AUROC of 0.99 ± 0.001 for FII or higher, the HVRI < 1.05 with a sensitivity and specificity of 100 and 91.43 %) compared to histopathologic workup (Desmet's score) and was comparable to TE analysis. Both HVRI and TE differed significantly in no or minimal fibrosis versus FII or higher (p < 0.001). In contrast, portal vein and hepatic artery did not show significant changes in blood flow in our study population.

CONCLUSIONS

Hepatic vein flow resistance index is a valuable tool in noninvasive evaluation of liver fibrosis in liver transplantation follow-up predicting FII or higher and might help reducing the number of protocol biopsies needed.

Liver Stiffness: A Significant Relationship with the Waveform Pattern in the Hepatic Vein

The aim of this prospective study was to assess the relationship between liver stiffness and hepatic vein waveform patterns in 42 patients with chronic hepatitis and 55 with cirrhosis. Liver stiffness measurement (LSM) values (FibroScan, Echosens, Paris, France) were significantly lower in the triphasic pattern group (11.3 ± 8.4 kPa) than in the monophasic pattern (32.5 ± 23.5 kPa, p = 0.001) and biphasic pattern (25.6 ± 18.1 kPa, p = 0.001) groups, indicating no significant relationship with portal pressure. The ability to diagnose cirrhosis represented by the highest area under the receiver operating characteristic curve was 0.921 (83.6% sensitivity, 90.5% specificity, best cutoff value: 16.9 kPa) by LSM and 1.000 (best cutoff value: 19.4 kPa) by LSM combined with the monophasic pattern. This study revealed a close linkage between liver stiffness and hepatic vein waveform findings, resulting in a better understanding of hepatic vein hemodynamics and wider application of its analysis.

Spectral Doppler of the Hepatic Veins in Noncardiac Diseases: What the Echocardiographer Should Know

In most instances, the flow profile in the hepatic veins (HVs) reflects the fluctuation of pressure within the right atrium. Thus, interrogation of blood flow in the HVs is highly useful for the evaluation of right heart hemodynamics and has become an integral part of any routine echocardiographic examination. However, flow in the HVs is also affected by the state of the liver parenchyma and by the fluctuation of pressure within the thoracic cavity. Therefore, liver and pulmonary pathologies influence the flow pattern in the HVs and may lead to its dissociation from right heart hemodynamics. Echocardiographers should familiarize themselves with the findings on HV Doppler in noncardiac diseases to avoid misinterpretation and incorrect diagnosis.

Role of ultrasound in the diagnosis and treatment of nonalcoholic fatty liver disease and its complications

We review the role of liver ultrasonography (US) and related techniques as non-invasive tools in predicting metabolic derangements, liver histology, portal hypertension and cardiovascular risk as well as allowing early diagnosis and management of hepatocellular carcinoma in patients with nonalcoholic fatty liver disease. In this setting, US detects fatty changes as low as ≥20% and hepatic steatosis identified ultrasonographically, in its turn, closely mirrors coronary and carotid atherosclerosis burden. Semi-quantitative US indices (to exclude nonalcoholic steatohepatitis) and sonoelastography (to quantify fibrosis) help in predicting liver histology and selecting patients to submit to liver biopsy. Surveillance for hepatocellular carcinoma conducted through biannual US is mandatory and US has a role in guiding locoregional treatment and in evaluating the efficacy of treatment. High-intensity focused ultrasound can be delivered with precision resulting in coagulative necrosis of hepatocellular carcinoma without puncturing the liver. Costs and inconveniences have so far hampered its diffusion.

Hemodynamic changes of the middle hepatic vein in patients with pulmonary hypertension using echocardiography

The aim of this study was to analyze the changes of the middle hepatic vein (MHV) spectra in patients with pulmonary hypertension (PH) caused by congenital heart disease (CHD) and determine the proper parameters of MHV to predict PH. Eighty patients with CHD were included, whose pulmonary artery pressure was measured via right heart catheterization, and the MHV spectra were detected via echocardiography. The peak value of velocity (V) and velocity time integral (VTI) of the waves, including S wave, D wave and A wave, were measured at the end of inspiration. The values of the MHV parameters that were predictive of PH were evaluated and their cut-off points were determined. Compared with the control group, V of S wave (S), VTI of S wave (SVTI), V of D wave (D), VTI of D wave (DVTI) decreased and V of A wave (A), VTI of A wave (AVTI), A/S, AVTI/SVTI, A/(S+D), AVTI/ (SVTI+DVTI) increased in the PH group. These differences were statistically significant (P<0.05). A correlation analysis determined that the ratios of A/S, A/(S+D), AVTI/(SVTI+DVTI) were positively correlated with pulmonary artery mean pressure (r=0.529,0.575,0.438,P<0.001). An ROC curve analysis determined that the diagnostic effect of A/(S+D) was superior to the other two parameters. On the ROC curve, when the ratio of A/(S+D) was 0.30, the sensitivity was 85.37% and specificity was 75.00% for predicting PH. The spectral parameters of MHV, including the ratios of A/S, A/(S+D) and AVTI/(SVTI+DVTI), increased with increasing pulmonary pressure in CHD patients. When the ratio of A/(S+D) was 0.30 in MHV spectra, it had sufficient sensitivity and specificity for diagnosing PH, and this method could be used as a new non-invasive complementary echocardiographic parameter for predicting PH.

Effects of fat accumulation in the liver on hemodynamic variables assessed by Doppler ultrasonography

PURPOSE

To investigate the effect of various degrees of fatty liver infiltration on hepatic hemodynamics using Doppler ultrasonography.

METHODS

We included 40 patients with hepatic steatosis and 20 healthy volunteers. Hepatic steatosis was quantified by a chemical shift MRI. Hepatic artery peak systolic and end-diastolic velocity, resistance index (RI) and pulsatility index (PI), hepatic vein RI and PI, portal vein RI, PI, congestion index, and peak maximum velocity were evaluated by Doppler ultrasonography. The hepatic vein waveforms were classified as triphasic, biphasic, or monophasic. Kruskal-Wallis test was performed for comparing more than two groups. If significant differences were found, Mann-Whitney U test with Bonferroni correction was performed for pair-wise comparisons. Pearson &gch;(2) and Fisher's exact tests were used to compare categorical variables.

RESULTS

According to MRI, 15 patients had mild, 14 patients had moderate, and 11 patients had severe fatty infiltration. Portal vein peak maximum velocity was median: 19.8 (range 12-33.3), 21.1 (8-41.8), 16.6 (10.6-24.9), and 29.2 (14.1-40.4) cm/s. Congestion index was 0.05 (0.02-0.16), 0.07 (0.01-0.17), 0.11 (0.06-0.24), and 0.05 (0.02-0.16). Hepatic artery RI was 0.75 (0.56-1.00), 0.66 (0.52-0.87), 0.83 (0.38-1.00), and 0.76 (0.48-2.76), and PI was 1.83 (0.90-3.13), 1.38 (1.04-2.63), 1.97 (0.86-2.90), and 1.82 (0.70-2.90) (p = .046 and p = .036) in the mild, moderate, severe steatosis, and control groups, respectively. The rate of triphasic hepatic vein waveforms was higher in controls than in patients with severe steatosis.

CONCLUSIONS

Portal vein flow velocity decreases in severe hepatic steatosis when compared with controls.

The role of ultrasonography in the evaluation of diffuse liver disease

The use of ultrasonography (US) to detect and characterize diffuse liver disease can be challenging, but remains a useful tool for the diagnosis and management of many diffuse parenchymal liver diseases such as cirrhosis, steatosis, and malignancies. Newer techniques, such as elastography, are proving useful for earlier detection of hepatic parenchymal changes. The role of US in the assessment of possible biliary ductal obstruction is well established, and Doppler US may provide additional physiologic information regarding hepatic blood flow. US plays a central role in target selection and guidance of percutaneous liver biopsies.

Doppler ultrasonography measurement of hepatic hemodynamics during Valsalva maneuver: healthy volunteer study

Purpose:

The aim of our study was to assess the hemodynamic change of liver during the Valsalva maneuver using Doppler ultrasonography.

Methods:

Thirty healthy men volunteers were enrolled (mean age, 25.5±3.64 years). The diameter, minimal and maximal velocities, and volume flow of intrahepatic inferior vena cava (IVC), middle hepatic vein (MHV), and right main portal vein (RMPV) was measured during both rest and Valsalva maneuver. These changes were compared using paired t-test.

Results:

The mean diameters (cm) of the intrahepatic IVC at rest and Valsalva maneuver were 1.94±0.40 versus 0.56±0.66 (P<0.001). The mean diameter (cm), minimal velocity (cm/sec), maximal velocity (cm/sec), and volume flow (mL/min) of MHV at rest and Valsalva maneuver were 0.60±0.15 versus 0.38±0.20 (P<0.001), -7.98±5.47 versus 25.74±13.13 (P<0.001), 21.34±6.89 versus 35.12±19.95 (P=0.002), and 106.94±97.65 versus 153.90±151.80 (P=0.014), respectively. Those of RMPV at rest and Valsalva maneuver were 0.78±0.21 versus 0.76±0.20 (P=0.485), 20.21±8.22 versus 18.73±7.43 (P=0.351), 26.79±8.85 versus 24.93±9.91 (P=0.275), and 391.52±265.63 versus 378.43±239.36 (P=0.315), respectively.

Conclusion:

The blood flow velocity and volume flow of MHV increased significantly during Valsalva maneuver. These findings suggest that hepatic vein might play an important role to maintain venous return to the heart during the maneuver.

Hepatic vein waveform and splenomegaly predict improvement of prothrombin time after splenectomy in hepatitis C virus-related cirrhotic patients

AIM

Whether hepatic function can recover in cirrhotic patients after splenectomy remains controversial.

METHODS

All consecutive Japanese patients with hepatic cirrhosis due to hepatitis C who had undergone elective splenectomy in Kyushu University Hospital between January 2008 and December 2009 were included in this retrospective study. Prothrombin time, serum albumin and total bilirubin concentrations were reviewed before and after splenectomy and analyzed to clarify whether splenectomy improves hepatic function in patients with cirrhosis and to determine the factors predictive of improvement in hepatic function.

RESULTS

Prothrombin time and total serum bilirubin concentration improved after splenectomy; however, serum albumin concentrations did not increase significantly. Twelve months after splenectomy, total serum bilirubin had decreased by over 0.3 mg/dL in 52.3% of patients and prothrombin time had improved by over 10% in 52.3% of patients. Multiple linear regression analysis identified hepatic vein waveform (HVWF) type I (P = 0.0174) and spleen weight (P = 0.0394) as independent predictors of improvement in prothrombin time and preoperative total serum bilirubin (P = 0.0002) as the only independent predictor of decrease in total bilirubin. Total bilirubin and prothrombin time were significantly improved after splenectomy in patients with HVWF type I, however, they were not improved in patients with HVWF type II.

CONCLUSION

Prothrombin time and total bilirubin improve in approximately half of cirrhotic patients within a year after splenectomy. HVWF type I and splenomegaly may be predictive factors for improvement in prothrombin time after splenectomy in patients with cirrhosis due to hepatitis C.

Correlation between Doppler of the right hepatic vein with ultrasound transcutaneous guided biopsy in liver diseases

OBJECTIVE

To correlate chronic liver disease diagnosed by transcutaneous liver biopsy guided by ultrasound, with ultrasound findings with B-mode and Doppler of the right hepatic vein; 2) to compare the wave patterns between the study group and the control group; 3) to compare the right hepatic vein Doppler findings with histopathology findings as a possible marker of chronic liver disease.

METHODS

Were studied 38 patients with chronic liver disease diagnosed by biopsy and serology (study group) and 10 persons without serologic liver disease (control group), assessed only by ultrasound B-mode and Doppler. The criteria were based on histology classification of the Brazilian Society of Pathology for chronic hepatitis. Chi-square, Fisher's exact and Student t tests were used.

RESULTS

The B-mode and Doppler ultrasound were useful in inferring the differentiation between individuals with chronic liver disease from normal. There were significant differences between the study group and the controls when comparing the histopathology findings, ultrasound B-mode and Doppler in relationship to the wave patterns of the right hepatic vein.

CONCLUSION

The correlation of liver biopsies with ultrasound B-mode and Doppler of hepatic vein was positive; 2) individuals with liver disease showed alterations in the flow of the right hepatic vein and normal subjects not, being the wave pattern in normal triphasic and in patients with chronic liver disease monophasic or biphasic; 3) Doppler of the right hepatic vein is useful marker for chronic liver disease.

Doppler ultrasound of hepatic blood flow for noninvasive evaluation of liver fibrosis compared with liver biopsy and transient elastography

BACKGROUND

Accurate quantification of liver fibrosis is essential for therapeutic decision-making and follow-up of chronic liver diseases.

AIMS

To optimize the quality of non-invasive assessment of liver fibrosis in patients with chronic hepatopathy we compared Doppler ultrasound with liver histology and transient elastography (TE).

METHODS

In this prospective observational study, we performed Doppler ultrasound of hepatic blood vessels as well as TE in 125 patients who underwent liver biopsy for diagnostic work-up of hepatopathy. Hepatic venous flow was evaluated by determining resistance index (HVRI) of the right hepatic vein. Doppler and TE results were compared with histological staging, grading and degree of steatosis obtained by liver biopsy.

RESULTS

HVRI showed a high reliability in predicting fibrosis stage FII or higher (AUROC 93.7 %, HVRI < 1.185; sensitivity 89.66 % and specificity 86.32 %) and was superior to TE. Neither steatosis nor inflammation had significant influence on HVRI-based estimation of fibrosis (1.45 ± 0.2; 1.26 ± 0.05; 1.06 ± 0.06; 0.87 ± 0.08; 0.46 ± 0.11 for F0-FIV, respectively). HVRI differed significantly in different stages of fibrosis. In contrast, portal vein and hepatic artery only showed significant changes in higher stages of fibrosis. Hepatic artery resistance index was elevated (0.67-0.74; p < 0.05); portal vein flow maximum and undulation were significantly reduced in higher fibrosis (p < 0.05 and p < 0.01, respectively).

CONCLUSIONS

Hepatic blood flow analysis, especially HVRI, provides useful information during assessment of hepatopathy and is a reliable predictor of liver fibrosis stage FII or higher as part of the non-invasive diagnostic work-up and follow-up in chronic liver disease.

Doppler sonography of patients with and without acute cellular rejection after right-lobe living donor liver transplantation

OBJECTIVES

To compare percent interval changes in the portal blood flow velocity (%PBV) and venous pulsatility index (%VPI), as determined by Doppler sonography, in patients with and without acute cellular rejection after right-lobe living donor liver transplantation.

METHODS

Forty-seven patients with biopsy-proven acute cellular rejection underwent Doppler sonography. The control group consisted of 47 age- and sex-matched patients without acute cellular rejection. Doppler spectrograms of the portal vein and right hepatic vein were used to calculate mean peak PBVs and VPIs for the first 3 days after right-lobe living donor liver transplantation, defined as PBV(Baseline) and VPI(Baseline). The PBV and VPI closest in time to biopsy in the patient group or at a matched time in the control group were determined as PBV(Event) and VPI(Event), and %PBV and %VPI values were calculated.

RESULTS

The mean PBV(Baseline) values ± SD in the rejection and control groups were 46.0 ± 21.8 and 44.4 ± 20.5 cm/s, respectively; the PBV(Event) values were 32.2 ± 14.5 and 34.4 ± 17.1 cm/s; and the %PBV values were 19.4% ± 39.9% and 2.2% ± 75.4% (P = .73; P = .38; P = .17, respectively). The VPI(Baseline) values were 0.92 ± 0.34 and 0.93 P = .94; P < .001); and the ± 0.38; the VPI(Event) values were 0.46 ± 0.33 and 0.84 ± 0.44 (%VPI values were 45.5% ± 40.1% and 5.6% ± 47.3%, with a greater than 50% VPI observed more frequently in the rejection than in the control group (61.7% versus 12.8%; P < .001).

CONCLUSIONS

The VPI(Event) was significantly lower and a greater than 50% VPI was significantly more frequent in patients with than without acute cellular rejection after right-lobe living donor liver transplantation.

Relationship between hepatic haemodynamics assessed by Doppler ultrasound and liver stiffness

AIM

We tested the relationship between hepatic haemodynamics assessed by Doppler ultrasonography and liver stiffness assessed by Transient Elastography in hepatitis C related chronic liver disease.

METHODS

Three liver Doppler ultrasound parameters (hepatic artery resistance index, splenic artery resistance index and waveform pattern in hepatic veins) and liver stiffness measured by Transient Elastography were analysed in one hundred consecutive patients affected by hepatitis C related chronic liver disease.

RESULTS

Hepatic and splenic arteries resistance indexes correlate significantly (p<0.0001 for both) with liver stiffness. A hepatic artery resistance index cut-off value of 0.64 provided sensitivity and specificity respectively of 84.4% and 69.1% for predicting liver stiffness ≤or >13 kPa, whereas a splenic artery resistance index cut-off value of 0.56 provided sensitivity and specificity respectively of 81.3% and 48.5%. The coincidental finding of both resistance indexes above the respective cut-off values showed a good accuracy in identifying patients with liver stiffness values >13 kPa (accuracy=78%, +LR=2.90, -LR=0.31). A significant difference in liver stiffness values was evident between patients with triphasic and bi- or monophasic waveform pattern (p=0.005).

CONCLUSIONS

Hepatic and splenic arteries resistance indexes and the hepatic veins waveform pattern assessed by Doppler ultrasound may provide information similar to that of Transient Elastography in hepatitis C related chronic liver disease.

Renal venous doppler ultrasonography in normal subjects and patients with diabetic nephropathy: value of venous impedance index measurements

OBJECTIVES

To provide reference values of intrarenal venous impedance index (VII) measured with duplex Doppler ultrasonography in a healthy adult population and to assess the usefulness this index for evaluating the functional status of kidney in patients with diabetic nephropathy (DN).

METHODS

Between May 2005 and December 2009, Doppler ultrasonography of both kidneys was performed in 164 healthy volunteers (controls) and 58 patients with DN. Renal interlobar and segmental vein Doppler waveforms and VII were obtained and compared between groups using the Student's t test. Correlation between VII and serum creatinine concentration (SCC) was calculated.

RESULTS

In controls, the mean VII was lower in interlobar than in segmental renal veins (p < 0.01), without difference between the right and left kidneys. Waveform modulation was dampened in DN patients whose mean VII (0.32 ± 0.18) was lower than in controls (0.38 ± 0.18) (p < 0.01). SCC showed moderate correlations (r = 0.65) with intrarenal VII in the patient group.

CONCLUSIONS

Renal VII is typically lower in DN than in controls and moderately correlated with SCC, which reflects renal function in DN, but does not offer a significant advantage over arterial resistance index.

Assessment of intrahepatic blood flow by Doppler ultrasonography: relationship between the hepatic vein, portal vein, hepatic artery and portal pressure measured intraoperatively in patients with portal hypertension

BACKGROUND

Abnormality of hepatic vein (HV) waveforms evaluated by Doppler ultrasonography has been widely studied in patients with chronic liver disease. We investigated the correlation between changes in HV waveforms and portal vein velocity (PVVel), the hepatic artery pulsatility index (HAPI), and also the extent of abnormal Doppler HV waveforms expressed as damping index (DI), severity of portal hypertension expressed as Child-Pugh scores and portal pressure (PP) measured directly from patients with portal hypertension (PHT) to evaluate the indicative value of abnormal HV waveforms and discuss the cause of abnormal HV waveform.

METHODS

Sixty patients who had been diagnosed with PHT and accepted surgical therapy of portosystemic shunts were investigated. PP was measured intraoperatively. Thirty healthy volunteers with no history of chronic liver disease were enrolled as the control group. HV waveforms were categorized as triphasic, biphasic or monophasic. DI was compared as the quantitative indicator of abnormal HV waveforms. Another two Doppler parameters, PVVel and HAPI were also measured. These Doppler features were compared with PP, Child-Pugh scores and histological changes assessed by liver biopsy.

RESULTS

In the patient group, the Doppler flow waveforms in the middle HV were triphasic in 31.6%, biphasic in 46.7%, and monophasic in 21.6% of subjects. These figures were 86.7%, 10.0%, and 3.3%, respectively, in healthy subjects. With the flattening of HV waveforms, the HAPI increased significantly (r = 00.438, p < 0.0001), whereas PVVel decreased significantly (r = -0.44, p <0.0001). Blood flow parameters, HAPI, PVVel and HV-waveform changes showed no significant correlations with Child-Pugh scores. The latter showed a significant correlation with PP (r = 0.589, p = 0.044). Changes of HV waveform and DI significantly correlated with PP (r = 0.579, r = 0.473, p <0.0001), and significant correlation between DI and Child-Pugh scores was observed (r = 0.411, p = 0.001). PP was significantly different with respect to nodule size (p < 0.05), but HV-waveform changes were not significantly correlated with pathological changes.

CONCLUSION

In patients with PHT, a monophasic HV waveform indicates higher portal pressure. Furthermore, quantitative indicator DI can reflect both higher portal pressure and more severe liver dysfunction. Flattening of HV waveforms accompanied by an increase in the HAPI and decrease in PVVel support the hypothesis that histological changes reducing HV compliance be the cause of abnormality of Doppler HV waveforms from the hemodynamic angle.

Changing waveform during respiration on hepatic vein Doppler sonography of severe portal hypertension: comparison with the damping index

OBJECTIVES

The purposes of this study were to assess retrospectively whether the waveform change during respiration on hepatic vein Doppler sonography is a parameter of severe portal hypertension as estimated by the hepatic venous pressure gradient (HVPG) and to compare with a hepatic vein damping index (DI) at expiration.

METHODS

Spectral Doppler sonography of the hepatic vein was performed on 22 consecutive patients who underwent HVPG measurement for portal hypertension with liver cirrhosis. From the maximum and minimum velocities of systolic hepatofugal venous flow on Doppler sonography, 3 parameters were derived: damping index at expiration (DI(exp)), damping index ratio (DI(ratio)), and damping index difference (ΔDI) between inspiration and expiration. Considering an HVPG level of 12 mm Hg or higher as the threshold level for high-grade portal hypertension, we assessed the diagnostic capability of these Doppler sonographic parameters to discriminate using receiver operating characteristic curve analysis.

RESULTS

Area under the curve values for the DI(ratio) and ΔDI (0.875 and 0.889, P = .807 and .682, respectively) were slightly higher than the area for the DI(exp) (0.861; respectively). When the DI(exp) was greater than 0.56, the sensitivity and specificity for high-grade portal hypertension were 66.7% and 100.0%, respectively. In the case of the DI(ratio), the sensitivity and specificity were 77.8%, and 100.0% at greater than 0.69. The corresponding sensitivity and specificity at a value of 0.25 or less for the ΔDI were 83.3% and 100.0%.

CONCLUSIONS

The ratio and difference of the DI of the hepatic vein waveform are helpful parameters in assessing the severity of portal hypertension as well as using the existing DI on its own.

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.

The role of transient elastography in patients with hepatitis B viral disease

This review focuses on the role of ultrasound and transient elastography (TE) in patients with hepatitis B virus (HBV) infection. Among the ultrasonographic signs analyzed, liver surface nodularity has the highest diagnostic accuracy and is particularly useful in confirming the presence of severe fibrosis or cirrhosis, due to its high specificity. The role of TE in patients with hepatitis B virus disease was assessed in inactive carriers and patients with chronic liver disease (CHB). In inactive HBV carriers, mean TE values are similar to normal controls and significantly lower than in patients with CHB. In this latter group, the available studies showed a significant positive correlation between TE values and fibrosis stages at liver histology. However, as for HCV patients, there is a certain degree of overlap among the lower stages of hepatic fibrosis and the accuracy of this technique is not optimal for the diagnosis of significant fibrosis, whereas its diagnostic performances are higher for the diagnosis of liver cirrhosis. The development of diagnostic algorithms, with a confirmatory and an exclusion liver stiffness threshold, seems to be a promising tool for a correct classification of patients.

Value of duplex doppler ultrasonography in non-invasive assessment of children with chronic liver disease

AIM: To investigate the value of duplex Doppler ultrasonography (US) in the assessment of the hemodynamics of the portal and hepatic veins in a cohort of children with chronic liver disease (CLD) and to detect any relationship between the US changes, etiology and severity (or stage) of CLD.

METHODS: We prospectively enrolled 25 children with biopsy-proven CLD. Thirteen had cirrhosis (aged 8.9 ± 2.0 years) and 12 had chronic hepatitis (aged 9.3 ± 2.3 years). Gray scale and color-coded duplex Doppler US were performed for all, as well as 30 healthy age and sex-matched controls. Findings were correlated with clinical, laboratory and histopathological characteristics.

RESULTS: Prominent caudate lobe was detected in 100% of cirrhotics, but none of the chronic hepatitis or controls. Thickened lesser omentum and loss of the triphasic waveform of the hepatic vein were present in 69.2% and 53.8% of cirrhotics vs 33.3% and 8.3% of chronic hepatitis respectively. Portal vein flow velocity was significantly lower (P < 0.0001) and the congestion index was significantly higher (P < 0.005) in both patient groups compared to controls. Child-Pugh’s staging showed a positive correlation with both abnormal hepatic vein waveform and direction of portal blood flow; and a negative correlation with both hepatic and portal vein flow velocities. No correlation with the etiology of CLD could be detected.

CONCLUSION: Duplex Doppler added to grayscale US can detect significant morphologic and portal hemodynamic changes that correlate with the severity (stage) of CLD, but not with etiology.

Hepatic vein waveforms in liver cirrhosis re-evaluated

OBJECTIVE

There are many studies on changes in Doppler waveforms of hepatic veins in cirrhotic liver. It is postulated that dampening of phasic oscillations appears with worsening of liver function. Our aim was to reevaluate the significance of Doppler waveforms of hepatic vein in cirrhotic patients and to correlate with hepatic blood flow.

PATIENTS AND METHOD

One hundred and thirty-five consecutive patients of liver cirrhosis and 60 age and sex matched non-cirrhotic controls were enrolled in this study. Doppler waveforms were obtained from right hepatic vein during normal respiration. Other parameters measured were flow volume of portal trunk, right portal vein and proper hepatic artery.

RESULT

Waveforms of the hepatic vein were classified into triphasic, biphasic and flat patterns. Flat waveform was rare and appeared in only 3% cases. There was no correlation between liver dysfunction and patterns of waveforms. Inflow, particularly to the right lobe, was significantly elevated in cases associated with the non-triphasic waveforms.

CONCLUSION

This study shows that the flat waveforms have no diagnostic value. Role of hepatic blood flow seems to be important suggesting hemodynamic changes rather than liver dysfunction as a plausible cause of change in waveforms.

Correlation of hepatic vein Doppler waveform and hepatic artery resistance index with the severity of nonalcoholic fatty liver disease

PURPOSE

The study was conducted to evaluate the effect of various degrees of fatty infiltration in patients with nonalcoholic fatty liver disease on hepatic artery resistance index and hepatic vein waveform patterns.

METHODS

After identification and grading of fatty infiltration, 60 patients and 20 normal healthy subjects were examined using color and spectral Doppler sonography. The level of fatty liver infiltration was ascertained and graded by biopsy in patients and excluded by MRI in controls. The patients were allocated to four study groups consecutively, until the required number was reached, according to infiltration level as follows: normal (group A), mild (group B), moderate (group C), and severe (group D). The hepatic vein waveforms were classified into the three following groups: triphasic, biphasic, and monophasic waveform. The hepatic artery resistance index was calculated as the mean of three different measurements.

RESULTS

The incidence of monophasic and biphasic hepatic vein waveform was 2 (10%) for group B, 11 (55%) for group C, 16 (80%) for group D, and none for group A. The difference in the distribution of triphasic Doppler waveform pattern between the patients and the control group was significant (p < 0.001). Hepatic artery resistance index was 0.81 (+ or - 0.02), 0.78 (+ or - 0.03), 0.73 (+ or - 0.03), and 0.68 (+ or - 0.05), respectively, in groups A, B, C, and D and was significantly different between groups (p < 0.001).

CONCLUSION

As the severity of nonalcoholic fatty infiltration increases, the incidence of abnormal hepatic vein waveforms increases and hepatic artery resistance index decreases.

Pearls and pitfalls in hepatic ultrasonography

Ultrasonography is often the initial imaging study in patients who present with right upper quadrant abdominal complaints. However, due to its intrinsic technical limitations, ultrasonography generally has a lower sensitivity than contrast-enhanced computed tomography or magnetic resonance imaging in detecting hepatic lesions. In this review, we describe several subtle sonographic signs that suggest the presence of an otherwise inconspicuous focal liver lesion, including disease in the pleural space or the lung parenchyma, refractive edge shadows, distorted or absent venous landmarks, abnormal Doppler patterns, and venous thrombosis. When encountered, these features should trigger careful evaluation of the adjacent areas for abnormalities and may warrant further studies with computed tomography, magnetic resonance imaging, or positron emission tomography. We also summarize common sonographic findings of diffuse liver diseases, including fatty infiltration and cirrhosis.

Understanding the spectral Doppler waveform of the hepatic veins in health and disease

Duplex Doppler sonography is a fundamental component of the complete ultrasonographic examination of the liver. Accurate interpretation of the spectral Doppler tracing from the hepatic veins is valuable, as it reflects important cardiac and hepatic physiology. Normally, there are four phases: A, S, V, and D; the S and D waves indicate flow in the antegrade direction toward the heart. In hepatic and cardiac disease, these normal waves may be absent, a finding indicative of flow in a nonphysiologic manner. In addition, transient patient factors such as phase of the respiratory cycle may influence the appearance of the spectral tracing. Familiarity with the normal and abnormal spectral Doppler waveforms from the hepatic veins and knowledge of their respective physiology and pathophysiology provide valuable insights. Systematic analysis of the direction, regularity, and phasicity of the spectral tracing and the ratio of the amplitudes of the S and D waves allows one to arrive at the correct differential diagnosis in most situations.

Aspectos ultrassonográficos e hemodinâmicos da esquistossomose mansônica: avaliação pela ultrassonografia Doppler em áreas endêmicas

OBJETIVO: Este estudo de campo objetivou identificar as alterações ultrassonográficas e hemodinâmicas indicativas da morbidade da esquistossomose mansônica em áreas endêmicas. MATERIAIS E MÉTODOS: Foram examinados pela ultrassonografia Doppler 554 pacientes esquistossomóticos em três áreas com níveis distintos de endemicidade: baixa endemicidade (n = 109); média endemicidade (n = 255) e alta endemicidade (n = 190). Para o estudo ultrassonográfico foi utilizado o protocolo da Organização Mundial da Saúde (Niamey Working Group, 2000). Pelo Doppler foram avaliados: vasos portais, artérias hepática e esplênica, veias hepáticas e vasos colaterais. RESULTADOS: Houve correlação significativa entre a frequência das alterações ultrassonográficas e o nível de endemicidade das áreas, exceto a hipertrofia do lobo esquerdo. As veias hepáticas apresentaram padrão de fluxo alterado em 23,7% dos casos, alteração esta relacionada à presença e à intensidade de espessamento periportal. A artéria hepática não apresentou alterações nos parâmetros avaliados. Os vasos colaterais foram identificados apenas na área de alta endemicidade. A artéria esplênica apresentou alterações (aumento do calibre, da velocidade e do índice de resistência) mais frequentes na área de alta endemicidade, com diferença significativa entre os grupos. CONCLUSÃO: A ultrassonografia Doppler mostrou-se ferramenta auxiliar importante no estudo da morbidade relacionada à esquistossomose mansônica, contribuindo para definição mais precisa do perfil da doença nas áreas endêmicas.

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.

Hepatic outflow obstruction at middle hepatic vein tributaries or inferior right hepatic veins after living donor liver transplantation with modified right lobe graft: comparison of CT and Doppler ultrasound

OBJECTIVE

The objective of our study was to compare CT and Doppler ultrasound in the diagnosis of hepatic outflow obstruction at the middle hepatic vein (MHV) tributaries and inferior right hepatic veins (RHVs) after living donor liver transplantation (LDLT) with modified right lobe grafts.

MATERIALS AND METHODS

Thirty-seven venographies were performed in 36 patients after LDLT with modified right lobe grafts, evaluating 51 MHV tributaries and 25 inferior RHVs. They were classified as obstructed or nonobstructed. On Doppler ultrasound or CT, flow patterns of the MHV tributaries and inferior RHVs or the relative parenchymal attenuation, enhancement, and opacification of these veins were evaluated for the diagnosis of hepatic outflow obstruction. McNemar tests were performed to compare the diagnostic values of Doppler ultrasound and CT.

RESULTS

On the basis of hepatic venography, 33 MHV tributaries were categorized as obstructed and 18 as nonobstructed, and 16 inferior RHVs were categorized as obstructed and nine as nonobstructed. For the diagnosis of MHV tributary obstruction, Doppler ultrasound was more sensitive and accurate, although less specific, than CT (97% vs 39%, respectively, p < 0.001; 86% vs 61%, p = 0.0209; 67% vs 100%, p = 0.0412). Similarly, Doppler ultrasound was more sensitive (94% vs 31%, respectively) and accurate (84% vs 56%) than CT, although less specific (67% vs 100%), for the diagnosis of inferior RHV obstruction, with a statistical significance only for sensitivity (p = 0.002, 0.092, and 0.248, respectively).

CONCLUSION

Doppler ultrasound is more sensitive and accurate than CT for the detection of obstruction at the MHV tributaries and inferior RHVs in patients after LDLT using modified right lobe grafts. Although current CT criteria produce high specificity and may reduce unnecessary invasive venographies, optimal CT criteria with acceptable sensitivity should be reestablished.

Hepatic vein morphology: a new sonographic diagnostic parameter in the investigation of cirrhosis?

OBJECTIVE

The purpose of this study was to evaluate the accuracy of a new sonographic marker for the diagnosis of cirrhosis using hepatic vein wall changes.

METHODS

A prospective pilot study evaluating 88 patients, 38 with cirrhosis and 50 with no evidence of liver disease, was undertaken. Hard copy sonograms of the hepatic veins were obtained and reviewed in a blinded fashion by 2 radiologists. The hepatic vein morphology was assessed by 3 parameters: hepatic vein wall straightness, uniformity of hepatic vein wall echogenicity, and visualization of a complete 1-cm hepatic vein segment. The 3 parameters were compared to evaluate sensitivity and specificity for the diagnosis of cirrhosis. Interobserver and intraobserver errors for each parameter were also calculated with kappa statistics to assess reproducibility.

RESULTS

There was a strong correlation between altered straightness and nonuniformity of hepatic vein wall echogenicity and cirrhosis. The straightness parameter had superior sensitivity of 97% (95% confidence interval [CI], 85%-100%) and specificity of 91% (95% CI, 78%-97%) for diagnosis of cirrhosis. Uniformity of hepatic vein wall echogenicity was the next most useful parameter, with sensitivity of 88% (95% CI, 73%-97%) and specificity of 86% (95% CI, 72%-95%). The continuous 1-cm segment of the hepatic vein had sensitivity of 68% (95% CI, 49%-83%) and specificity of 91% (95% CI, 78%-97%). Hepatic vein evaluation was found to show both good intraobserver and interobserver error.

CONCLUSIONS

Hepatic vein morphology on sonography, in particular, changes in the straightness and uniformity of hepatic vein wall echogenicity, is a new sign of cirrhosis, which may increase the overall accuracy of sonographic diagnosis of cirrhosis and which appears to have a moderately high degree of reproducibility.

Non-invasive evaluation of liver cirrhosis using ultrasound

Ultrasound (US) is essential in both assessment of the potentially cirrhotic liver and surveillance of selected patients with chronic hepatitis as liver biopsy can be misleading or inaccurate in up to 25% of cases. Various techniques are already in routine use, such as grey-scale imaging, Doppler US, and contrast-enhanced US (CEUS), while newer techniques such as elastography and hepatic vein transit time (HVTT) have the potential to exclude patients without significant fibrosis or cirrhosis; however, they are operator dependent and require specific software. Grey-scale imaging may demonstrate changes, such as volume redistribution, capsule nodularity, parenchymal nodularity, and echotexture changes. The Doppler findings in the hepatic and portal veins, hepatic artery, and varices allow assessment of liver cirrhosis. However, the operator needs to be aware of limitations of these techniques. Low mechanical index CEUS plays an important role in the assessment of complications of cirrhosis, such as hepatocellular carcinoma and portal vein thrombus. Optimized US technique is crucial for accurate diagnosis of the cirrhotic liver and its complications.