Ultrasonography for Noninvasive Assessment of Portal Hypertension

The Prediction and Treatment of Bleeding Esophageal Varices in the Artificial Intelligence Era: A Review

Esophageal varices (EVs), a significant complication of cirrhosis, present a considerable challenge in clinical practice due to their high risk of bleeding and associated morbidity and mortality. This manuscript explores the transformative role of artificial intelligence (AI) in the management of EV, particularly in enhancing diagnostic accuracy and predicting bleeding risks. It underscores the potential of AI in offering noninvasive, efficient alternatives to traditional diagnostic methods such as esophagogastroduodenoscopy (EGD). The complexity of EV management is highlighted, necessitating a multidisciplinary approach that includes pharmacological therapy, endoscopic interventions, and, in some cases, surgical options tailored to individual patient profiles. Additionally, the paper emphasizes the importance of integrating AI into medical education and practice, preparing healthcare professionals for the evolving landscape of medical technology. It projects a future where AI significantly influences the management of gastrointestinal bleeding, improving clinical decision-making, patient outcomes, and overall healthcare efficiency. The study advocates for a patient-centered approach in healthcare, balancing the incorporation of innovative technologies with ethical principles and the diverse needs of patients to optimize treatment efficacy and enhance healthcare accessibility.

Methods for assessing portal hypertension

Many researchers and clinicians have taken the value of hepatic venous pressure gradient (HVPG) as an essential prognostic factor in subjects with chronic liver diseases. HVPG ≥ 10 mmHg indicates the presence of clinically significant portal hypertension, the main predictor of the risk of variceal bleeding, hepatic decompensation, and mortality. However, HVPG measurement is invasive and requires high expertise, so its routine use outside tertiary care centers or clinical trials is limited. Clinically significant portal hypertension also might be detected using non-invasive options such as ultrasonography, elastography, magnetic resonance imaging, and indices derived from laboratory parameters. Our review aims to present the feasibility and applicability of HVPG in modern clinical practice in patients with liver cirrhosis, including invasive and non-invasive methods, based on literary sources from the MEDLINE database.

Exogenous Volatile Organic Compound (EVOC®) Breath Testing Maximizes Classification Performance for Subjects with Cirrhosis and Reveals Signs of Portal Hypertension

Background: Cirrhosis detection in primary care relies on low-performing biomarkers. Consequently, up to 75% of subjects with cirrhosis receive their first diagnosis with decompensation when causal treatments are less effective at preserving liver function. We investigated an unprecedented approach to cirrhosis detection based on dynamic breath testing. Methods: We enrolled 29 subjects with cirrhosis (Child-Pugh A and B), and 29 controls. All subjects fasted overnight. Breath samples were taken using Breath Biopsy® before and at different time points after the administration of 100 mg limonene. Absolute limonene breath levels were measured using gas chromatography-mass spectrometry. Results: All subjects showed a >100-fold limonene spike in breath after administration compared to baseline. Limonene breath kinetics showed first-order decay in >90% of the participants, with higher bioavailability in the cirrhosis group. At the Youden index, baseline limonene levels showed classification performance with an area under the roc curve (AUROC) of 0.83 ± 0.012, sensitivity of 0.66 ± 0.09, and specificity of 0.83 ± 0.07. The best performing timepoint post-administration was 60 min, with an AUROC of 0.91, sensitivity of 0.83 ± 0.07, and specificity of 0.9 ± 0.06. In the cirrhosis group, limonene bioavailability showed a correlation with MELD and fibrosis indicators, and was associated with signs of portal hypertension. Conclusions: Dynamic limonene breath testing enhances diagnostic performance for cirrhosis compared to static testing. The correlation with disease severity suggests potential for monitoring therapeutic interventions. Given the non-invasive nature of breath collection, a dynamic limonene breath test could be implemented in primary care.

Radiological Diagnosis of Chronic Liver Disease and Hepatocellular Carcinoma: A Review

Medical image analysis plays a pivotal role in the evaluation of diseases, including screening, surveillance, diagnosis, and prognosis. Liver is one of the major organs responsible for key functions of metabolism, protein and hormone synthesis, detoxification, and waste excretion. Patients with advanced liver disease and Hepatocellular Carcinoma (HCC) are often asymptomatic in the early stages; however delays in diagnosis and treatment can lead to increased rates of decompensated liver diseases, late-stage HCC, morbidity and mortality. Ultrasound (US) is commonly used imaging modality for diagnosis of chronic liver diseases that includes fibrosis, cirrhosis and portal hypertension. In this paper, we first provide an overview of various diagnostic methods for stages of liver diseases and discuss the role of Computer-Aided Diagnosis (CAD) systems in diagnosing liver diseases. Second, we review the utility of machine learning and deep learning approaches as diagnostic tools. Finally, we present the limitations of existing studies and outline future directions to further improve diagnostic accuracy, as well as reduce cost and subjectivity, while also improving workflow for the clinicians.

Can Emergency Physicians Diagnose Cirrhosis by Ultrasound: A Prospective Single-Arm Educational Intervention

Background and purpose Liver cirrhosis is common, and timely diagnosis of decompensated cirrhosis may impact acute care and resuscitation. Point-of-care ultrasound is a core competency of US emergency medicine training and is increasingly available in many acute care settings, including those where usual diagnostic modalities of cirrhosis may not be available. Only a few works of literature exist that evaluate the ultrasound diagnosis of cirrhosis and decompensated cirrhosis by emergency physicians (EPs). We aim to evaluate whether EPs can diagnose cirrhosis by ultrasound after a brief educational intervention and determine the accuracy of EP-interpreted ultrasound compared to the radiology-interpreted ultrasound as a gold standard. Methods This single-center prospective single-arm educational intervention evaluated the accuracy of EPs diagnosing cirrhosis and decompensated cirrhosis on ultrasound before and after a short educational intervention. Responses were paired across the three assessments, and paired sample t-tests were performed. Sensitivity, specificity, and likelihood ratios were calculated using attending radiology-interpreted ultrasounds as the gold standard. Results EPs scored a mean of 16% higher on a delayed knowledge assessment one month after the educational intervention than on the pre-intervention assessment. EP-interpreted ultrasound revealed a sensitivity of 0.90, specificity of 0.71, positive likelihood ratio of 3.08, and negative likelihood ratio of 0.14 compared to radiology-interpreted ultrasound. The sensitivity of our cohort was 0.98 for decompensated cirrhosis. Conclusions After a brief educational intervention, EPs can significantly increase their sensitivity and specificity in diagnosing cirrhosis using ultrasound. EPs were particularly sensitive in their diagnosis of decompensated cirrhosis.

Liver and heart failure: an ultrasound relationship

Liver and heart are anatomically and patho-physiologically related. In heart failure (HF) the increased right atrial pressure and volume overload cause histological changes in hepatocytes, leading to a condition known as "congestive hepatopathy" (CH), with consequent variations in liver functioning and ultrasound (US) findings. CH has specifical US findings especially regarding venous vessels aspect, easily detecting by gray-scale study, but many others can be distinguished by Doppler analysis. Usually, hepatic veins look enlarged and hypocollassing, together with signs of portal hypertension (hepatomegaly, ascites, splenomegaly, porto-systemic collaterals). Typically, in CH Doppler findings regard alterations in venous vessel flow and arterial resistance (venous system hyperpulsatility, reduced velocity flow, high resistance index in hepatic arterial Doppler spectrum). Sometimes CH and other primary hepatopathy can coexist, and therefore some of the expected variations may not manifest: it allows suspecting an unknown underlying liver disease. At last, US technologies of more recent applications, even if not routinely used, allow investigating additional aspects such as elastography that detects changes in liver elasticity or contrastographic US, able to show differences in hepatic venous opacification. However, most of these US signs are not pathognomonic, and therefore a multidisciplinary clinical reasoning must not be lacking. The aim of the present review is to easily provide US signs of liver alterations in HF, in particular right heart failure with volume overload, suggesting including liver US in instrumental diagnosis and therapeutic monitoring of HF.

Hepatic perfusion as a new predictor of prognosis and mortality in critical care patients with acute-on-chronic liver failure

Background and aims

Liver diseases are frequent causes of morbidity and mortality worldwide. Liver diseases can lead to cirrhosis, with the risk of acute-on-chronic liver failure (ACLF). For the detection of changes in hepatic hemodynamics, Doppler ultrasonography is a well-established method. We investigated hepatic hemodynamics via serial Doppler ultrasonography to determine the predictive value of changes in hepatic perfusion for the outcome in patients with severe liver diseases compared to established prognostic models such as the MELD (Model for End-Stage Liver Disease) or CLIF-C (Chronic Liver Failure-Consortium) ACLF score.

Methods

In this prospective cohort study, hepatic perfusion was quantified at baseline before the initiation of treatment and every third day by means of serial measurements of the hepatic artery resistance index (HARI) and the maximum portal vein velocity (PVv) using Doppler ultrasonography in 50 consecutive patients with severe liver diseases admitted to a medical intensive care unit (MICU). The recorded hemodynamic parameters were compared to the MELD score, and the CLIF-C ACLF score to analyze their utility for the prediction of the outcome of patients with severe liver diseases, liver cirrhosis, and ACLF.

Results

The changes (delta) obtained by serial measurements of the MELD score, HARI, and PVv were analyzed through scatter plots. Bivariate correlation analysis yielded a new positive linear correlation between the delta-HARI and the delta-MELD score (r = 0.469; p < 0.001). In addition, our data revealed a new negative linear correlation between delta-PVv and the delta-MELD score (r = −0.279, p = 0.001). The leading cause of MICU mortality was acute-on-chronic liver failure (ACLF). A subgroup analysis of patients with liver cirrhosis revealed a positive linear correlation between the delta-HARI and the delta-CLIF-C-ACLF score (r = 0.252, p = 0.005). Of clinical relevance, non-survivors of ACLF exhibited a significantly higher mean value for the delta-HARI (0.010 vs. −0.005; p = 0.015) and a lower mean value for the delta-PVv (−0.7 vs. 1.9 cm/s; p = 0.037) in comparison to survivors of ACLF.

Conclusion

This study shows the prognostic value of the assessment of hepatic perfusion in critical care patients with severe liver diseases by bedside Doppler ultrasound examination and its utility as an accurate predictor of the outcome in patients with ACLF. Increasing HARI and a decreasing PVv are predictors of an adverse outcome. Delta-HARI and delta-PVv are new biomarkers of prognosis and ACLF-related mortality in patients with liver diseases. Delta-HARI and delta-PVv may be helpful in guiding clinical decision-making, especially in catecholamine and fluid management.

Development and validation of a nomogram for esophagogastric variceal bleeding in liver cirrhosis: A cohort study in 1099 cases

OBJECTIVES

Esophagogastric variceal bleeding (EVB) is a catastrophic complication of decompensated liver cirrhosis. We aimed to establish a nomogram based on noninvasive clinical and imaging variables to predict the risk of EVB.

METHODS

The cut-off value of each variable was determined through univariate regression analysis. The least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression analyses were used to determine the risk factors and establish predictive models. The nomogram was established and validated using the calibration discrimination across different groups.

RESULTS

Six indicators, including platelet count, hemoglobin, albumin to globulin ratio, fasting blood glucose, serum chloride, and computed tomography portal vein diameter (CTPD), were found to be related to the risk of EVB. Two models, with or without CTPD, were established and compared. Model 1 with CTPD had better discrimination than model 2 with C-index of 0.893 (95% confidence interval [CI] 0.872-0.915) and 0.862 (95% CI 0.837-0.887) in the primary cohort, respectively (Z = 2.027, P = 0.043). While the C-index of the two models in the validation cohort was 0.878 (95% CI 0.838-0.919) and 0.810 (95% CI 0.757-0.863). Moreover, the clinical decision analysis curve and clinical impact curve showed that these models might confer a significant net benefit on patients and provide a reference threshold for clinicians.

CONCLUSION

A nomogram using routine clinical indicators was established to predict the risk of EVB in patients with liver cirrhosis, which was verified in an independent cohort and demonstrated a great consistency.

Bibliometric-analysis visualization and review of non-invasive methods for monitoring and managing the portal hypertension

Background

Portal hypertension monitoring is important throughout the natural course of cirrhosis. Hepatic venous pressure gradient (HVPG), regarded as the golden standard, is limited by invasiveness and technical difficulties. Portal hypertension is increasingly being assessed non-invasively, and hematological indices, imaging data, and statistical or computational models are studied to surrogate HVPG. This paper discusses the existing non-invasive methods based on measurement principles and reviews the methodological developments in the last 20 years.

Methods

First, we used VOSviewer to learn the architecture of this field. The publications about the non-invasive assessment of portal hypertension were retrieved from the Web of Science Core Collection (WoSCC). VOSviewer 1.6.17.0 was used to analyze and visualize these publications, including the annual trend, the study hotspots, the significant articles, authors, journals, and organizations in this field. Next, according to the cluster analysis result of the keywords, we further retrieved and classified the related studies to discuss.

Results

A total of 1,088 articles or review articles about our topic were retrieved from WoSCC. From 2000 to 2022, the number of publications is generally growing. “World Journal of Gastroenterology” published the most articles (n = 43), while “Journal of Hepatology” had the highest citations. “Liver fibrosis” published in 2005 was the most influential manuscript. Among the 20,558 cited references of 1,088 retrieved manuscripts, the most cited was a study on liver stiffness measurement from 2007. The highest-yielding country was the United States, followed by China and Italy. “Berzigotti, Annalisa” was the most prolific author and had the most cooperation partners. Four study directions emerged from the keyword clustering: (1) the evaluation based on fibrosis; (2) the evaluation based on hemodynamic factors; (3) the evaluation through elastography; and (4) the evaluation of variceal bleeding.

Conclusion

The non-invasive assessment of portal hypertension is mainly based on two principles: fibrosis and hemodynamics. Liver fibrosis is the major initiator of cirrhotic PH, while hemodynamic factors reflect secondary alteration of splanchnic blood flow. Blood tests, US (including DUS and CEUS), CT, and magnetic resonance imaging (MRI) support the non-invasive assessment of PH by providing both hemodynamic and fibrotic information. Elastography, mainly USE, is the most important method of PH monitoring.

The severity of portal hypertension by a non-invasive assessment: acoustic structure quantification analysis of liver parenchyma

Background

Acoustic structure quantification (ASQ) has been applied to evaluate liver histologic changes by analyzing the speckle pattern seen on B-mode ultrasound. We aimed to assess the severity of portal hypertension (PHT) through hepatic ultrasonography.

Methods

Sixty patients diagnosed with PHT and underwent surgical treatment with portosystemic shunts were enrolled. Portal pressure (PP) was measured intraoperatively. Patients were divided into subgroups according to the severity of gastroesophageal varices and Child–Pugh class. Three difference ratio (C_m²) values on ASQ histogram mode were analyzed for their relationships with PP, degree of gastroesophageal varices and Child–Pugh liver function. Thirty healthy volunteers matched with the patients for gender and age were enrolled as controls. Comparisons among groups and correlation of the parameters with PP were analyzed. Area under the receive operating characteristic curve was used to evaluate the predicting value of ASQ parameters.

Results

In the patients, the ASQ parameters peak C_m² (C_m²_max), mean C_m² (C_m²_mean) and the highest occurred C_m² value of the obtained red curve (R_maxC_m²) were all greatly increased (P < 0.0001, P < 0.0001, P = 0.027). Multiple comparisons indicated that, regardless of Child–Pugh class and degree of gastroesophageal varices, the patients had significantly increased C_m²_max and C_m²_mean compared with the controls (all P < 0.0001). No differences among subgroups were observed. C_m²_max was significantly statistically correlated with PP (r = 0.3505, P < 0.01), degree of varices (r = 0.4998, P < 0.0001). Youden’s index for C_m²_max with a cut-off value of 140.3 for predicting the presence of PHT, gastroesophageal varices and liver function equal to or worse than Child–Pugh class B were 0.8, 0.91 and 0.84, respectively.

Conclusions

ASQ analysis of ultrasonographic images may have a role in the evaluation of the severity of PHT by detecting liver histologic changes in the speckle pattern caused by cirrhosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00817-2.

Quantitative measurements of esophageal varices using computed tomography for prediction of severe varices and the risk of bleeding: a preliminary study

BACKGROUND

We aimed to assess whether the quantitative parameters of esophageal varices (EV) based on computed tomography (CT) can noninvasively predict severe EV and the risk of esophageal variceal bleeding (EVB).

METHODS

A total of 136 endoscopically confirmed EV patients were included in this retrospective study and were divided into a non-conspicuous (mild-to-moderate EV, n = 30) and a conspicuous EV group (severe EV, n = 106), a bleeding (n = 89) and a non-bleeding group (n = 47). EV grade (EVG), EV diameter (EVD), cross-sectional surface area (CSA), EV volume (EVV), spleen volume (SV), splenic vein (SNV), portal vein (PV), diameter of left gastric vein (DLGV), and the opening type of LGV were measured independently using 3D-slicer. Univariate and multivariate logistic analysis were used to determine the independent factors and the receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic performance.

RESULTS

The difference of EVG, EVD, CSA, EVV, DLGV, SNV between the conspicuous and non-conspicuous EV group were statistically significant (p < 0.05), area under the curves (AUCs) of them for predicting severe EV were 0.72, 0.772, 0.704, 0.768, 0.707, 0.65, with corresponding sensitivities of 70.3%, 63.5%, 50%, 74.3%, 52.7%, 48.6%, specificities of 71.4%, 85.7%, 100%, 71.4%, 81%, 81%, respectively. EVG, CSA (odds ratio 3.258, 95% CI 1.597-6.647; 1.029, 95% CI 1.008-1.050) were found to be independent predictive factors. However, there was no significant difference of the included indices between the bleeding and non-bleeding group (p > 0.05).

CONCLUSIONS

CT can be used as a noninvasive method to predict the severity of EV, which may reduce the invasive screening of endoscopy.

Portal venous pressure in non-cirrhotic bilharzial patients undergoing elective splenectomy, can it affect mortality? A prospective study

Background and study aims

To evaluate the impact of intraoperatively measured portal vein pressure (PVP) on mortality in non-cirrhotic bilharzial patients undergoing splenectomy.

Methods

The present study is a prospective study that was conducted in Egypt from April 2014 to April 2018. Adult patients with non-cirrhotic bilharziasis who were scheduled to undergo splenectomy were included. Studied cases were divided into a survival cohort and a non-survival cohort. The main objective was the correlation between the incidence of mortality and intraoperative PVP.

Results

The present work comprised 130 cases with a mean age of 51.8 ± 6.4 years old. The in-hospital mortality rate was 22.3%, with sepsis as a major cause of death (37.9%). In term of the association between preoperative variables and mortality, survivors had statistically significant lower portal vein diameter (13.6 ± 1.8 versus 15.2 ± 1.8mm; p<0.001) and higher portal vein velocity (14.2 ± 1.8 versus 10.4 ± 2.3 cm/sec; p<0.001) than nonsurvivors. The survived patients had significantly lower PVP (13.9 ± 1.1 versus 17.7 ± 2.7; p<0.001). A cut-off value of ≥14.5 mmHg, the PVP yielded a sensitivity of 86.2% and a specificity of 69% for the prediction of mortality. The association analysis showed a statistically significant association between mortality and postoperative liver function parameters.

Conclusions

High intraoperative PVP is linked to early postoperative death in non-cirrhotic cases undergoing splenectomy. Our study showed that PVP > 14.5mmHg was an independent predictor of death and showed good diagnostic performance for the detection of early postoperative mortality.

First-Pass Arrival Interval of Ultrasound Contrast Medium in the Hepatic Artery and Portal Vein as a Marker for Assessment of Liver Transplant Recipients

BACKGROUND

This study measures the first-pass arrival times in the hepatic artery and portal vein of the transplanted liver using contrast-enhanced ultrasound (CEUS) and assess its correlation with graft performance in the early posttransplant period.

METHODS

This study evaluated 35 liver transplant recipients who underwent CEUS examination within 1 month of transplant surgery. CEUS under contrast-specific harmonic imaging mode were recorded for 60 seconds immediately after intravenous administration of microbubble ultrasound contrast medium (Sonazoid, GE Healthcare, Oslo, Norway). The recorded video clips were reviewed by 2 readers to determine the first-pass arrival times in the hepatic artery and portal vein, and the difference between the 2 was defined as the arterial-portal arrival interval (APAI). Laboratory data on the same date of CEUS examination were collected as indicators to correlate with APAI.

RESULTS

The intra- and inter-rater reliability for APAI measurement were excellent, with intraclass correlation coefficients > .95. The mean APAI was 4.5 ± 1.8 seconds (range, 2.0-10.5 seconds). The APAI was positively correlated with the serum total bilirubin level (r = 0.357, P = .035) and negatively correlated with the platelet count (r = -0.354, P = .037). At the 5 second cutoff point, a total serum bilirubin of >8 mg/dL was reported in 5 of 11 patients (45.4%) with APAI of >5 seconds and in only 3 of 24 patients (12.5%) with APAI of <5 seconds (P < .05).

CONCLUSIONS

The APAI is a quantitative marker that links the hemodynamics and the clinical status of the liver graft.

Artificial Intelligence in Imaging of Chronic Liver Diseases: Current Update and Future Perspectives

Here we review artificial intelligence (AI) models which aim to assess various aspects of chronic liver disease. Despite the clinical importance of hepatocellular carcinoma in the setting of chronic liver disease, we focus this review on AI models which are not lesion-specific and instead review models developed for liver parenchyma segmentation, evaluation of portal circulation, assessment of hepatic fibrosis, and identification of hepatic steatosis. Optimization of these models offers the opportunity to potentially reduce the need for invasive procedures such as catheterization to measure hepatic venous pressure gradient or biopsy to assess fibrosis and steatosis. We compare the performance of these AI models amongst themselves as well as to radiomics approaches and alternate modality assessments. We conclude that these models show promising performance and merit larger-scale evaluation. We review artificial intelligence models that aim to assess various aspects of chronic liver disease aside from hepatocellular carcinoma. We focus this review on models for liver parenchyma segmentation, evaluation of portal circulation, assessment of hepatic fibrosis, and identification of hepatic steatosis. We conclude that these models show promising performance and merit a larger scale evaluation.

Increased canine pancreatic lipase immunoreactivity (cPLI) and 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase in dogs with evidence of portal hypertension and normal pancreatic histology: a pilot study

The clinical presentations of both liver disease and pancreatitis are nonspecific and overlapping, which may cause difficulty in diagnosis. In our retrospective pilot study, we assessed whether dogs with evidence of portal hypertension and absence of pancreatitis on pancreatic histology have increases in canine pancreatic lipase immunoreactivity (cPLI) and 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase. We included dogs that had been presented between 2008 and 2019 if they had normal pancreatic histology, histologically confirmed hepatopathy, and if canine pancreas-specific lipase (Spec cPL; Idexx) or DGGR lipase had been measured. Only dogs with portal hypertension were included. Six dogs fulfilled the inclusion criteria. Four of 6 and 2 of 6 dogs had Spec cPL and DGGR lipase exceeding the upper reference limit, respectively. From the 4 dogs with increased Spec cPL, 2 had concentrations of 200-400 µg/L and 2 had concentrations ≥ 400 µg/L. Our results suggest that canine portal hypertension might lead to increased Spec cPL and DGGR lipase values in the absence of pancreatitis on histology. Until more evidence in a larger number of dogs with portal hypertension is available, both tests should be interpreted cautiously in the presence of portal hypertension.

Application of Hepatic Transit Time and Shear Wave Velocity in Assessing Portal Pressure in Patients with Cirrhotic Portal Hypertension

The aim of the study described here was to explore the value of hepatic transit time (HTT) and shear wave velocity (SWV) in diagnosing cirrhotic portal hypertension. Fifty-seven patients had undergone esophagogastric varicose vein embolization (group OBS) and 50 healthy controls (group CON) were retrospectively compared with respect to HTT (arterial-hepatic vein [HA-HVTT], portal vein-hepatic vein [PV-HVTT], liver parenchyma-hepatic vein [PA-HVTT]) and SWV to analyze their efficacy in diagnosing cirrhotic portal hypertension. The correlations between SWV/HTT and free portal pressure (FPP) in group OBS were also analyzed. Compared with group CON, group OBS had a shorter HTT and faster SWV. The area under the curve (AUC) of PV-HVTT (0.93) was higher than those of HA-HVTT (0.75) and PA-HVTT (0.64), the AUCs of PV-HVTT (0.93, threshold 7.9 s) and SWV (0.91, threshold 2.0 cm/s) did not statistically differ (z = 0.35, p = 0.73). HTT and FPP in group OBS had a negative correlation. In conclusion, HTT and SWV can be used to diagnose cirrhotic portal hypertension without difference in diagnostic efficacy, and HTT is more meaningful for assessing the changes in portal pressure.

Shear wave elastography and transient elastography in HCV patients after direct-acting antivirals

PURPOSE

To compare the ultrasound (US) and pulse shear wave elastography (pSWE, Elast PQ^®) methods with transient elastography (TE), clinical scores and laboratory tests, during the follow-up of HCV patients receiving direct-acting antiviral drugs (DAA).

METHODS

Our prospective study from June 2016 to December 2017 included 22 consecutively enrolled HCV-positive patients (59.7 ± 12.3 years, 11 male) which were subjected to antiviral therapy. All patients underwent B-mode ultrasound, color-Doppler, pSWE and TE five times: before therapy (T0), at the end of therapy (post-Tx), and at 12, 24, 48 weeks post-therapy. The liver stiffness (LS) values obtained with pSWE and TE and the data coming from US assessment and clinical evaluation were compared.

RESULTS

We obtained a statistically significant reduction of LS values (kPa) measured by pSWE, between T0 (14.3 ± 9.3), post-Tx (11.8 ± 10.5), 12 weeks (7.5 ± 3.3), 24 weeks (8 ± 3.8) and 48 weeks (8.5 ± 4.6) (p = 0.02). The reduction of kPa measured by TE was not significant between T0 (14.7 ± 9.3), post-Tx (12 ± 9.5), 12 weeks (11.6 ± 7.7), 24 weeks (10.3 ± 6) and 48 weeks (10.8 ± 7.5) (p > 0.05). Multivariate baseline analysis showed significant independent association among measurement of TE stiffness with cirrhosis, type of vein hepatic flow and showed significant independent association between delta-pSWE measurement (difference between stiffness measurements at the baseline and 12 months after treatment) with staging of fibrosis (p = 0.006) and sustained virologic response after 12 weeks of treatment (SVR12, p = 0.017).

CONCLUSION

The pSWE method has shown better ability than TE to identify a reduction in LS. Therefore, pSWE allow to evaluate stiffness reduction in HCV patient during DAA treatment follow-up, which is related to SVR12.

Liver fibrosis index-based nomograms for identifying esophageal varices in patients with chronic hepatitis B related cirrhosis

BACKGROUND

Esophageal varices (EV) are the most fatal complication of chronic hepatitis B (CHB) related cirrhosis. The prognosis is poor, especially after the first upper gastrointestinal hemorrhage.

AIM

To construct nomograms to predict the risk and severity of EV in patients with CHB related cirrhosis.

METHODS

Between 2016 and 2018, the patients with CHB related cirrhosis were recruited and divided into a training or validation cohort at The First Affiliated Hospital of Wenzhou Medical University. Clinical and ultrasonic parameters that were closely related to EV risk and severity were screened out by univariate and multivariate logistic regression analyses, and integrated into two nomograms, respectively. Both nomograms were internally and externally validated by calibration, concordance index (C-index), receiver operating characteristic curve, and decision curve analyses (DCA).

RESULTS

A total of 307 patients with CHB related cirrhosis were recruited. The independent risk factors for EV included Child-Pugh class [odds ratio (OR) = 7.705, 95% confidence interval (CI) = 2.169-27.370, P = 0.002], platelet count (OR = 0.992, 95%CI = 0.984-1.000, P = 0.044), splenic portal index (SPI) (OR = 3.895, 95%CI = 1.630-9.308, P = 0.002), and liver fibrosis index (LFI) (OR = 3.603, 95%CI = 1.336-9.719, P = 0.011); those of EV severity included Child-Pugh class (OR = 5.436, 95%CI = 2.112-13.990, P < 0.001), mean portal vein velocity (OR = 1.479, 95%CI = 1.043-2.098, P = 0.028), portal vein diameter (OR = 1.397, 95%CI = 1.021-1.912, P = 0.037), SPI (OR = 1.463, 95%CI = 1.030-2.079, P = 0.034), and LFI (OR = 3.089, 95%CI = 1.442-6.617, P = 0.004). Two nomograms (predicting EV risk and severity, respectively) were well-calibrated and had a favorable discriminative ability, with C-indexes of 0.916 and 0.846 in the training cohort, respectively, higher than those of other predictive indexes, like LFI (C-indexes = 0.781 and 0.738), SPI (C-indexes = 0.805 and 0.714), ratio of platelet count to spleen diameter (PSR) (C-indexes = 0.822 and 0.726), King’s score (C-indexes = 0.694 and 0.609), and Lok index (C-indexes = 0.788 and 0.700). The areas under the curves (AUCs) of the two nomograms were 0.916 and 0.846 in the training cohort, respectively, higher than those of LFI (AUCs = 0.781 and 0.738), SPI (AUCs = 0.805 and 0.714), PSR (AUCs = 0.822 and 0.726), King’s score (AUCs = 0.694 and 0.609), and Lok index (AUCs = 0.788 and 0.700). Better net benefits were shown in the DCA. The results were validated in the validation cohort.

CONCLUSION

Nomograms incorporating clinical and ultrasonic variables are efficient in noninvasively predicting the risk and severity of EV.

Accurate ultrasonography-based portal pressure assessment in patients with hepatocellular carcinoma

BACKGROUND

Portal pressure is of great significance in the treatment of hepatocellular carcinoma (HCC), but direct measurement is complicated and costly; thus, non-invasive measurement methods are urgently needed.

AIM

To investigate whether ultrasonography (US)-based portal pressure assessment could replace invasive transjugular measurement.

METHODS

A cohort of 102 patients with HCC was selected (mean age: 54 ± 13 years, male/female: 65/37). Pre-operative US parameters were assessed by two independent investigators, and multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for the portal pressure gradient (PPG). The estimated PPG predictors were compared with the transjugular PPG measurements. Validation was conducted on another cohort of 20 non-surgical patients.

RESULTS

The mean PPG was 17.32 ± 1.97 mmHg. Univariate analysis identified the association of the following four parameters with PPG: Spleen volume, portal vein diameter, portal vein velocity (PVV), and portal blood flow (PBF). Multiple linear regression analysis was performed, and the predictive formula using the PVV and PBF was as follows: PPG score = 19.336 - 0.312 × PVV (cm/s) + 0.001 × PBF (mL/min). The PPG score was confirmed to have good accuracy with an area under the curve (AUC) of 0.75 (0.68-0.81) in training patients. The formula was also accurate in the validation patients with an AUC of 0.820 (0.53-0.83).

CONCLUSION

The formula based on ultrasonographic Doppler flow parameters shows a significant correlation with invasive PPG and, if further confirmed by prospective validation, may replace the invasive transjugular assessment.

Nonalcoholic fatty liver disease and portal hypertension

Nonalcoholic fatty liver disease (NAFLD) is a substantial and growing problem worldwide and has become the second most common indication for liver transplantation as it may progress to cirrhosis and develop complications from portal hypertension primarily caused by advanced fibrosis and erratic tissue remodeling. However, elevated portal venous pressure has also been detected in experimental models of fatty liver and in human NAFLD when fibrosis is far less advanced and cirrhosis is absent. Early increases in intrahepatic vascular resistance may contribute to the progression of liver disease. Specific pathophenotypes linked to the development of portal hypertension in NAFLD include hepatocellular lipid accumulation and ballooning injury, capillarization of liver sinusoidal endothelial cells, enhanced contractility of hepatic stellate cells, activation of Kupffer cells and pro-inflammatory pathways, adhesion and entrapment of recruited leukocytes, microthrombosis, angiogenesis and perisinusoidal fibrosis. These pathological events are amplified in NAFLD by concomitant visceral obesity, insulin resistance, type 2 diabetes and dysbiosis, promoting aberrant interactions with adipose tissue, skeletal muscle and gut microbiota. Measurement of the hepatic venous pressure gradient by retrograde insertion of a balloon-tipped central vein catheter is the current reference method for predicting outcomes of cirrhosis associated with clinically significant portal hypertension and guiding interventions. This invasive technique is rarely considered in the absence of cirrhosis where currently available clinical, imaging and laboratory correlates of portal hypertension may not reflect early changes in liver hemodynamics. Availability of less invasive but sufficiently sensitive methods for the assessment of portal venous pressure in NAFLD remains therefore an unmet need. Recent efforts to develop new biomarkers and endoscopy-based approaches such as endoscopic ultrasound-guided measurement of portal pressure gradient may help achieve this goal. In addition, cellular and molecular targets are being identified to guide emerging therapies in the prevention and management of portal hypertension.

Sofosbuvir-Velpatasvir Fixed Drug Combination for the Treatment of Chronic Hepatitis C Infection in Patients With End-Stage Renal Disease and Kidney Transplantation

INTRODUCTION

India is witnessing high hepatitis C virus (HCV) infection burden in patients of chronic kidney disease. Due to unavailability of costly Kidney Disease Improving Global Outcomes-recommended directly acting antiviral drugs, a widely available pan-genotypic combination of Sofosbuvir and Velpatasvir can become an economical option. Data regarding treatment experience of sofosbuvir-velpatasvir combination in chronic kidney disease is scarce. No data from India have been published in patients on renal replacement therapies till now.

METHODS

This retrospective analysis included all patients of end-stage renal disease on maintenance hemodialysis with treatment-naïve chronic HCV infection treated with sofosbuvir (400 mg) and velpatasvir (100 mg) fixed-dose combination. Pretreatment routine investigations were performed, which included HCV viral load, genotype, fibro scan, endoscopy for esophageal varices, and portal vein Doppler. The patients were followed up with HCV viral load to declare sustained virologic response.

RESULT

patients were included with a mean age of 39.8 ± 10.8 years, and 77.4% were male. Genotype 1 was found to be most prevalent (67.7%), with a median viral load of 106copies/ml. Six (19.3%) patients had hepatitis B virus co-infection. Three (9.7%) patients had cirrhosis. Sustained virologic response (SVR12) was achieved in 30 (96.8%) patients, and one (3.2%) patient had relapse. Furthermore, 14 (45.2%) patients underwent renal transplantation, and none of them had relapsed. Dyspepsia (9.7%) was the most common side effect observed with no major adverse effect.

CONCLUSION

Our study showed excellent efficacy with the safety profile of this drug combination in end-stage renal disease patients. However, larger prospective studies and multicenter randomized controlled trials are needed for further confirmation.

Paraumbilical vein aneurysm: case report

A 48-year-old female patient was found to have a paraumbilical vein saccular aneurysm, which is a rare consequence of portal hypertension. She presented with right upper quadrant pain and had a known diagnosis of alcoholic liver disease. This had progressed since her last admission. We discuss the multimodality images obtained, diagnosis and complications associated with this pathology.

Preoperative color Doppler ultrasonography predicts early recurrence in AFP-positive hepatocellular carcinoma

The present study aimed to evaluate the hepatic hemodynamics of patients with α-fetoprotein (AFP)-positive hepatocellular carcinoma (HCC) and early recurrence (ER), as determined by color Doppler ultrasound. Screening with color Doppler ultrasound was performed in 150 patients with AFP-positive HCC, yielding 43 cases with postoperative ER. In addition, 35 healthy controls were enrolled in the study for comparison of the blood flow parameters between the healthy control and the HCC groups. Receiver operating characteristic curve analysis was performed to evaluate the predicted effect of Doppler for the ER of HCC. The average mean flow velocity of portal vein in patients with HCC (14.686±5.873 cm/s) was significantly lower in the HCC group compared with the healthy control group (17.631±3.569 cm/s; P=0.005). Additionally, the preoperative portal vein diameter in the HCC group was significantly higher compared with that in the healthy control group (P=0.001). Regarding the effect of surgery, the portal vein diameter was significantly increased in the patients postoperatively compared with preoperatively (P=0.003), while the pulsation and resistance indexes exhibited a decreasing trend in the postoperative group (P=0.001 and P=0.003, respectively). Notably, patients with HCC and ER presented with a higher resistance index (1.163±0.342) compared with the ER-free group (1.023±0.176; P=0.004). Furthermore, a significant difference in hepatic artery pulsation index was also observed between the ER group (0.673±0.075) and the ER-free group (0.624±0.056; P=0.018), indicating that an increased hepatic artery pulsation index may significantly predict the ER of HCC. In addition, areas under the curve of 0.683 and 0.700, respectively, suggested that the hepatic artery resistance and pulsation indexes may be used to diagnose ER in HCC (P=0.009 and P=0.004, respectively). Taken together, Doppler ultrasound provides a reliable and accurate quantification of hepatic hemodynamics for detecting ER in HCC with a good diagnostic accuracy.

Portal pressure monitoring-state-of-the-art and future perspective

Portal hypertension is a serious symptom of chronic liver diseases, which can lead to many critical complications, such as the formation of varices related to upper digestive bleeding, ascites, infection, hepatic encephalopathy, renal failure, and even death. As a result, portal pressure monitoring has important prognostic and clinical implications. The hepatic venous pressure gradient measurement, a gold-standard method applied to monitor portal pressure, is invasive and only available in experienced centers. Over the past decade, noninvasive methods aimed at monitoring the portal pressure have been increasingly investigated, including serum markers, radiological features, ultrasound elastography, doppler and contrast-enhanced ultrasonography. In this study, we focused on both invasive and noninvasive methods for portal pressure monitoring and explored their roles in clinical setting. The advantages and limitations of various techniques for future research are also discussed.

Application of the Hepatic Transit Time (HTT) in Evaluation of Portal Vein Pressure in Gastroesophageal Varices Patients

OBJECTIVES

To analyze the clinical significance of using hepatic transit time (HTT) to evaluate portal vein pressure in gastroesophageal varices patients.

METHODS

For the observation group, we enrolled 50 gastroesophageal varices patients who had received esophagogastric variceal embolization in our hospital between January 2015 and February 2018. Patients without liver disease populated the control group and were recruited during the same time period. All patients underwent contrast-enhanced sonography. In the observation group, free portal pressure (FPP) was detected during esophagogastric variceal embolization with ultrasound guidance. Differences in hepatic artery-hepatic vein transit time (HA-HVTT), portal vein-hepatic vein transit time (PV-HVTT), and parenchyma-hepatic vein transit time (PA-HVTT) were compared between groups. Correlations between HA-HVTT, PV-HVTT, PA-HVTT, and FPP in the observation group were analyzed using the Pearson coefficient and linear regression analysis.

RESULTS

HA-HVTT (t = 5.078; P < .001), PV-HVTT (t = 12.163; P < .001), and PA-HVTT (t = 2.649; P = .009) within the observation group were significantly lower than those of the control group. The areas under the curve of HTT were 0.771 (HA-HVTT), 0.951 (PV-HVTT), and 0.652 (PA-HVTT), and the sensitivity and specificity of PV-HVTT at 7.99 seconds were 86.0% and 88.0%, respectively. The HA-HVTT (r = -0.799; P < .001), PV-HVTT (r = -0.554; P < .001), and PA-HVTT (r = -0.735; P < .001) negatively correlated to FPP in the observation group. Linear regression analysis showed y = -0.410x + 7.254 (HA-HVTT and FPP), y = -0.335x + 4.983 (PV-HVTT and FPP), and y = -0.566x + 4.997 (PA-HVTT and FPP) in the observation group.

CONCLUSION

Compared with the control patients, the HTT of patients with portal hypertension-esophagogastric varices was significantly shorter, and showed an inverse relationship with FPP.

A critical appraisal of the use of ultrasound in hepatic steatosis

Introduction: Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). NAFLD carries an increased risk of cardio-metabolic and liver-related events accounting for a substantial economic burden. Given that the natural history of NAFLD is critically dependent on the stage of fibrosis, non-invasively identifying the subgroup of patients at a higher risk of progressive disease is key. Areas covered: This review highlights the recent developments in the use of ultrasound-based techniques in NAFLD and their performance in predicting metabolic derangements, cardiovascular risk, and progression of liver disease, notably including diagnosis of fibrosing NASH, identification, and treatment of HCC. Expert opinion: Our ability to identify NAFLD patients and to estimate steatofibrosis with various ultrasound-based techniques has undergone tremendous progress over the last few years. However, it is more difficult to capture the inflammatory component of NASH with such ultrasound-assisted techniques. Moreover, semi-quantitative, quantitative, elastographic, and contrast-enhanced ultrasound techniques are increasingly being appreciated and made available but not all such techniques will gain success in the clinical and research area. Therefore, further research will precisely define the role of the most innovative ultrasonographic techniques, while reducing costs and increasing feasibility.

Emerging non-invasive approaches for diagnosis and monitoring of portal hypertension

Clinically significant portal hypertension is associated with an increased risk of developing gastro-oesophageal varices and hepatic decompensation. Hepatic venous pressure gradient measurement and oesophagogastroduodenoscopy are the gold-standard methods for assessing clinically significant portal hypertension (hepatic venous pressure gradient ≥10 mm Hg) and gastro-oesophageal varices, respectively. However, invasiveness, cost, and feasibility limit their widespread use, especially if repeated and serial evaluations are required to assess the efficacy of pharmacotherapy. Although new techniques for non-invasive portal pressure measurement have been pursued for many decades, only recently have new tools been assessed and validated for larger clinical application. This Review focuses on the recent advances in non-invasive approaches for the diagnosis and serial monitoring of portal hypertension and varices for clinical practice.

Advances in ultrasound diagnosis in chronic liver diseases

Chronic liver disease is a major disorder worldwide. A better understanding of anatomy, blood flow, and pathophysiology may be a key issue for their proper management. Ultrasound (US) is a simple and non-invasive diagnostic tool in the abdominal field. Doppler mode offers real-time hemodynamic evaluation, and the contrast-enhanced US is one of the most frequently used modalities for the detailed assessment. Further development in digital technology enables threedimensional (3D) visualization of target images with high resolution. This article reviews the wide ranges of application in the abdominal US and describes the recent progress in the diagnosis of chronic liver diseases.

Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient’s survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points

• Fontan procedure for functional single ventricle has improved patient survival into adulthood.

• Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease.

• Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease.

• Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0609-2) contains supplementary material, which is available to authorized users.

Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.