Optimization of Point-Shear Wave Elastography by Skin-to-Liver Distance to Assess Liver Fibrosis in Patients Undergoing Bariatric Surgery

Predicting response to non-selective beta-blockers with liver-spleen stiffness and heart rate in patients with liver cirrhosis and high-risk varices

INTRODUCTION

Non-selective beta-blockers (NSBB) are used for primary prophylaxis in patients with liver cirrhosis and high-risk varices (HRVs). Assessing therapeutic response is challenging due to the invasive nature of hepatic venous pressure gradient (HVPG) measurement. This study aims to define a noninvasive machine-learning based approach to determine response to NSBB in patients with liver cirrhosis and HRVs.

METHODS

We conducted a prospective study on a cohort of cirrhotic patients with documented HRVs receiving NSBB treatment. Patients were followed-up with clinical and elastography appointments at 3, 6, and 12 months after NSBB treatment initiation. NSBB response was defined as stationary or downstaging variceal grading at the 12-month esophagogastroduodenoscopy (EGD). In contrast, non-response was defined as upstaging variceal grading at the 12-month EGD or at least one variceal hemorrhage episode during the 12-month follow-up. We chose cut-off values for univariate and multivariate model with 100% specificity.

RESULTS

According to least absolute shrinkage and selection operator (LASSO) regression, spleen stiffness (SS) and liver stiffness (LS) percentual decrease, along with changes in heart rate (HR) at 3 months were the most significant predictors of NSBB response. A decrease > 11.5% in SS, > 16.8% in LS, and > 25.3% in HR was associated with better prediction of clinical response to NSBB. SS percentual decrease showed the highest accuracy (86.4%) with high sensitivity (78.8%) when compared to LS and HR. The multivariate model incorporating SS, LS, and HR showed the highest discrimination and calibration metrics (AUROC = 0.96), with the optimal cut-off of 0.90 (sensitivity 94.2%, specificity 100%, PPV 95.7%, NPV 100%, accuracy 97.5%).

A single-center, retrospective, cross-sectional study comparing the number of non-diagnostic measurements ratio in the pSWE and SSI ultrasound elastography methods

The point shear wave elastography and supersonic shear imaging methods were compared regarding incorrect measurements during the liver examinations. A report-based, single-center, retrospective analysis of 425 liver elastography examinations was performed. A lower success ratio was observed for the point shear wave elastography method, as well as the older and obese patients pre-dominated in non-diagnostic studies. In our center experience, it is easier to obtain diagnostic data using the supersonic shear imaging method. However, further investigation of the subject is needed.

Contrast-Enhanced Ultrasonography with Arrival Time Parametric Imaging as a Non-Invasive Diagnostic Tool for Liver Cirrhosis

Liver biopsy is the gold standard method for staging liver fibrosis, but it is an invasive procedure that is associated with some complications. There are also non-invasive techniques for assessing liver fibrosis, such as elastography and biological tests, but these techniques can fail in detection or generate false measurements depending on the subject’s condition. This study aimed to determine whether liver fibrosis can be evaluated using contrast-enhanced ultrasonography with arrival time parametric imaging using the ultrasound machine’s parametric image software, the method being called (CEUS-PAT). CEUS-PAT was performed on each subject using SonoVue as a contrast agent, and images showing liver parenchyma and the right kidney on a single screen were used for analysis in parametric imaging, which was performed using the proprietary software of the ultrasound system. The ratio between the kidney and liver arrival times was calculated. The study included 64 predominantly male (56.3%) subjects, 37 cirrhotic patients, and 27 healthy volunteers, with a mean age of 58.98 ± 8.90 years. Significant differences were found between the liver cirrhosis and healthy groups regarding CEUS-PAT, 0.83 ± 0.09 vs. 0.49 ± 0.11, p < 0.0001. The correlation between CEUS-PAT and VCTE was r = 0.81. The optimal cut-off value for detecting liver cirrhosis was >0.7, with an AUC of 0.98, p < 0.001, Se = 89.19%, Sp = 100%, PPV = 100%, and NPV = 87.1%. We demonstrate that CEUS-PAT achieves excellent performance in diagnosing liver cirrhosis and is a fast method for diagnosing liver cirrhosis that can even be applied in situations where the use of other methods is excluded.

Ultrasound-Based Hepatic Elastography in Non-Alcoholic Fatty Liver Disease: Focus on Patients with Type 2 Diabetes

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease and is the hepatic expression of metabolic syndrome. The development of non-invasive methods for the diagnosis of hepatic steatosis and advanced fibrosis in high-risk patients, especially those with type 2 diabetes mellitus, is highly needed to replace the invasive method of liver biopsy. Elastographic methods can bring significant added value to screening and diagnostic procedures for NAFLD in patients with diabetes, thus contributing to improved NAFLD management. Pharmacological development and forthcoming therapeutic measures that address NAFLD should also be based on new, non-invasive, and reliable tools that assess NAFLD in at-risk patients and be able to properly guide treatment in individuals with both diabetes and NAFLD. This is the first review aiming to outline and discuss recent studies on ultrasound-based hepatic elastography, focusing on NAFLD assessment in patients with diabetes.

Liver fibrosis assessment: MR and US elastography

Elastography has emerged as a preferred non-invasive imaging technique for the clinical assessment of liver fibrosis. Elastography methods provide liver stiffness measurement (LSM) as a surrogate quantitative biomarker for fibrosis burden in chronic liver disease (CLD). Elastography can be performed either with ultrasound or MRI. Currently available ultrasound-based methods include strain elastography, two-dimensional shear wave elastography (2D-SWE), point shear wave elastography (pSWE), and vibration-controlled transient elastography (VCTE). MR Elastography (MRE) is widely available as two-dimensional gradient echo MRE (2D-GRE-MRE) technique. US-based methods provide estimated Young's modulus (eYM) and MRE provides magnitude of the complex shear modulus. MRE and ultrasound methods have proven to be accurate methods for detection of advanced liver fibrosis and cirrhosis. Other clinical applications of elastography include liver decompensation prediction, and differentiation of non-alcoholic steatohepatitis (NASH) from simple steatosis (SS). In this review, we briefly describe the different elastography methods, discuss current clinical applications, and provide an overview of advances in the field of liver elastography.

Noninvasive Assessment of Liver Fibrosis with ElastPQ in Patients with Chronic Viral Hepatitis: Comparison Using Histopathological Findings

Chronic viral hepatitis is a major cause of chronic liver disease leading to liver fibrosis. This study aimed to assess the diagnostic performance of elastography point quantification (ElastPQ), transient elastography (TE), and aspartate aminotransferase-to-platelet count ratio index (APRI) for the staging of liver fibrosis in patients with chronic viral hepatitis using histopathological findings as a reference standard. For 122 patients with chronic viral hepatitis, diagnostic performance was evaluated using area under the receiver operating characteristic curve (AUROC) analysis and correlations were determined using Spearman’s correlation coefficient. The AUROC of ElastPQ for the diagnosis of the fibrosis stage ≥ F2 was 0.917 with a cut-off value of 3.935. There was a significant positive correlation between the different stages of histologic liver fibrosis and stiffness values obtained using ElastPQ, TE, and APRI (ρ = 0.556, ρ = 0.657, ρ = 0.375, respectively; p < 0.001). ElastPQ showed a higher diagnostic accuracy than APRI, resembling that of TE; AUROC values of ElastPQ, TE, and APRI were 0.917, 0.964, and 0.896, respectively, for a fibrosis stage ≥ F2. ElastPQ is a promising noninvasive technique with a diagnostic accuracy comparable with that of TE for the evaluation of liver fibrosis in patients with chronic viral hepatitis.

The Utility and Diagnostic Accuracy of Transient Elastography in Adults with Morbid Obesity: A Prospective Study

Patients with morbid obesity are at high risk for nonalcoholic fatty liver disease (NAFLD) complicated by liver fibrosis. The clinical utility of transient elastography (TE) by Fibroscan in patients with morbid obesity (body mass index (BMI) ≥ 40 kg/m2) is not well-defined. We examined the diagnostic accuracy of Fibroscan in predicting significant liver fibrosis (fibrosis stage ≥2) in morbidly obese patients (BMI ≥ 40 kg/m2). Patients scheduled for bariatric surgery were prospectively enrolled. Intraoperative liver biopsy, liver-stiffness measurement (LSM) by Fibroscan (XL probe), and biochemical evaluation were all performed on the same day. The endpoint was significant liver fibrosis defined as fibrosis stage ≥2 based on the Nonalcoholic Steatohepatitis Clinical Research Network. The optimal LSM cutoff value for detecting significant fibrosis was determined by using the Youden Index method. Routine clinical, laboratory, and elastography data were analyzed by stepwise logistic regression analysis to identify predictors of significant liver fibrosis and build a predictive model. An optimal cutoff point of the new model's regression formula for predicting significant fibrosis was determined by using the Youden index method. One hundred sixty-seven patients (mean age, 46.4 years) were included, of whom 83.2% were female. Histological assessment revealed the prevalence of steatohepatitis and significant fibrosis of 40.7% and 11.4%, respectively. The median LSM was found to be significantly higher in the significant fibrosis group compared to those in the no or non-significant fibrosis group (18.2 vs. 7.7 kPa, respectively; p = 0.0004). The optimal LSM cutoff for predicting significant fibrosis was 12.8 kPa, with an accuracy of 71.3%, sensitivity of 73.7%, specificity of 70.9%, positive predictive value of 24.6%, negative predictive value of 95.5%, and ROC area of 0.723 (95% CI: 0.62-0.83). Logistic regression analysis identified three independent predictors of significant fibrosis: LSM, hemoglobin A1c, and alkaline phosphatase. A risk score was developed by using these three variables. At an optimal cutoff value of the regression formula, the risk score had an accuracy of 79.6% for predicting significant fibrosis, sensitivity of 89.5%, specificity of 78.4%, positive predictive value of 34.7%, negative predictive value of 98.3%, and ROC area of 0.855 (95% CI: 0.76-0.95). Fibroscan utility in predicting significant liver fibrosis in morbidly obese subjects is limited with accuracy of 71.3%. A model incorporating hemoglobin A1c and alkaline phosphatase with LSM improves accuracy in detecting significant fibrosis in this patient population.

Comparison of Visual Transient Elastography and Shear Wave Elastography in Evaluating Liver Fibrosis in Patients with Chronic Liver Disease

Purpose

This study investigated the effectiveness and feasibility of shear wave elastography ((sound touch elastography) STE and (shear wave elastography) SWE) and visual transient elastography (ViTE) in the noninvasive quantitative diagnosis of liver fibrosis in chronic liver disease (CLD).

Patients and Methods

A total of 106 patients with CLD underwent STE, SWE and ViTE elastography evaluation. The Young’s modulus of the three elastography was valuated and the diagnostic performances of the three techniques for liver fibrosis staging were compared. The area under the receiver operating curve (ROC) for the diagnosis of liver fibrosis was compared. The final diagnosis was based on the histological findings on the liver biopsy.

Results

1) The correlation between ViTE and SWE, ViTE and STE, SWE and STE stiffness values were 0.72, 0.75, 0.75 (P<0.001). 2) The relationship between the results of each elastography technique and the stage of pathological liver fibrosis showed that the more severe the liver fibrosis was, the higher the stiffness value was (all P <0.001). 3) When the three elastography techniques were used to detect the degree of liver fibrosis in different pathological stages, there was no statistical difference in the stabilities of the boxplots. 4) The ROCs of the three elastography techniques (ViTE, SWE and STE) were 0.88, 0.91, 0.92, F0 vs F1-3; 0.84, 0.84, 0.84, F0-1 vs F2-4; 0.80, 0.79, 0.77, F0-2 vs F3-4; 0.80, 0.76, 0.71, F0-3 vs 4; the AUC of ViTE was higher than the AUC of STE in the identification of F4, but there were no statistical differences in the AUCs of other groups.

Conclusion

ViTE has good stability for the liver stiffness measurement (LSM) and a high consistency with shear-wave elastography (SWE and STE). It is an effective tool for evaluating CLD, and its performance is comparable to SWE and STE. The combination of ViTE and STE can improve the specificity of disease diagnosis and do not add extra cost and may improve cost performance.

What does liver elastography measure? Technical aspects and methodology

Elastography can be thought as an extension of the ancient technique of palpation. After giving a short introduction to the history of elastography, the different technologies that are nowadays available and the physics behind them, the article focuses on the assessment of liver stiffness in patients with diffuse liver disease using shear wave elastography (SWE). Practical advices on how to perform the SWE techniques and on the factors that should be considered for a correct interpretation of the results are given. This paper aimed to provide a practical guide for beginners and advanced clinical users to better understand technical aspects, methodologies and terminology.

The role of elastography in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its prevalence is even higher in patients with risk factors such as type 2 diabetes and obesity. Liver biopsy is the gold standard for diagnosis of non-alcoholic steatohepatitis (NASH), particularly for the assessment of fibrosis stage that is a key prognostic factor. Noninvasive methods for assessment of liver fibrosis are a huge need in contemporary hepatology in order to stratify patient's risk of advanced and progressive liver disease. In this perspective different imaging techniques have been developed in last decades and showed high performance in liver fibrosis evaluation. Strengths and weaknesses of all imaging methods are summarized in this review.

Metformin Actions on the Liver: Protection Mechanisms Emerging in Hepatocytes and Immune Cells against NASH-Related HCC

Nonalcoholic fatty liver disease (NAFLD) is strongly linked to the global epidemic of obesity and type 2 diabetes mellitus (T2DM). Notably, NAFLD can progress from the mildest form of simple steatosis to nonalcoholic steatohepatitis (NASH) that increases the risk for hepatocellular carcinoma (HCC), which is a malignancy with a dismal prognosis and rising incidence in the United States and other developed counties, possibly due to the epidemic of NAFLD. Metformin, the first-line drug for T2DM, has been suggested to reduce risks for several types of cancers including HCC and protect against NASH-related HCC, as revealed by epidemical studies on humans and preclinical studies on animal models. This review focuses on the pathogenesis of NASH-related HCC and the mechanisms by which metformin inhibits the initiation and progression of NASH-related HCC. Since the functional role of immune cells in liver homeostasis and pathogenesis is increasingly appreciated in developing anti-cancer therapies on liver malignancies, we discuss both the traditional targets of metformin in hepatocytes and the recently defined effects of metformin on immune cells.

The Effect of Genetic Polymorphism in Response to Body Weight Reduction in Japanese Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

weight loss as a result of lifestyle intervention is effective when treating non-alcoholic fatty liver disease (NAFLD). We estimated the effects of PNPLA3 rs738409 and HSD17B13 rs6834314 variants in response to diet therapy in Japanese patients with NAFLD.

METHODS

we analyzed the correlation between the change in liver stiffness and change in body weight in 140 patients administered diet therapy for 1-year, according to PNPLA3 and HSD17B13 genotypes.

RESULTS

the bodyweight (BW) reduction rate was greater in patients with the PNPLA3 genotype CC than CG and GG (p = 0.035). Change in liver stiffness measurement (LSM) was significantly associated with a change in BW in PNPLA3 CG/GG (r = 0.279/0.381), but not in PNPLA3 CC (p = 0.187). Change in LSM was correlated with change in BW only in patients with HSD17B13 AG/GG (r = 0.425), but not the AA genotype (p = 0.069). A multivariate analysis identified that a change in LSM was correlated with a change in BW in carriers of HSD17B13 AG/GG (B = 3.043, p = 0.032), but not HSD17B13 AA. The change in LSM of patients with a BW reduction of more than 7% (0.50) was significantly greater than that of patients with a BW reduction of less than 7% (0.83) (p = 0.038).

CONCLUSIONS

in Japanese patients with NAFLD, HSD17B13 rs6834314 polymorphism is associated with the change in LSM by lifestyle intervention. The approach, including genetic assessments, may contribute to the establishment of appropriate therapeutic strategies to treat NAFLD.

The Combination of Shear Wave Elastography and Platelet Counts Can Effectively Predict High-Risk Varices in Patients with Hepatitis B-Related Cirrhosis

Background

Baveno VI criteria, based on liver stiffness (LS) measured by transient elastography and platelet counts (PLT), have been proposed to avoid unnecessary endoscopy screening for high-risk varices (HRVs). However, the cut-off value of LS measured by 2D-SWE and PLT to predict HRVs in compensated hepatitis B-related cirrhotic patients remains unknown.

Aims

To prospectively analyze the cut-off of the combination of LS measured by 2D-SWE and PLT in predicting HRVs and the influence of antiviral therapies in its efficacy.

Methods

Serum parameters, LS, and endoscopy results were obtained from 160 compensated hepatitis B-related cirrhotic patients. The accuracy of the combined algorithm was assessed in the whole cohort and subgroups with or without consecutive antiviral therapies in the past 6 months.

Results

In the whole cohort, the optimal cut-off value of LS for HRVs was 14.5 kPa. Patients with a LS value < 14.5 kPa with a PLT value > 110 × 10⁹/L can be excluded from HRVs (NPV = 0.99, endoscopy saved rates = 0.68). Conversely, a LS value of ≥14.5 kPa and a PLT value of ≤110 × 10⁹/L indicated HRVs, with accurate rates of 82.35%, and 10.63% of patients can avoid additional endoscopy screening. Moreover, antiviral therapy had no significant effect on the accuracy and rates saved from further endoscopy screening, when comparing patients with or without antiviral therapies (all p values > 0.05).

Conclusions

The combination of LS (14.5 kPa) measured by 2D-SWE and PLT (110 × 10⁹/L) can predict HRVs accurately in compensated hepatitis B-related cirrhotic patients without significant interference of antiviral therapy histories.

Shear Wave Elastography and Shear Wave Dispersion Imaging in the Assessment of Liver Disease in Alpha1-Antitrypsin Deficiency

Liver affection of Alpha1-antitrypsin deficiency (AATD) can lead to cirrhosis and hepatocellular carcinoma (HCC). A noninvasive severity assessment of liver disease in AATD is urgently needed since laboratory parameters may not accurately reflect the extent of liver involvement. Preliminary data exist on two-dimensional shear wave elastography (2D-SWE) being a suitable method for liver fibrosis measurement in AATD. AATD patients without HCC were examined using 2D-SWE, shear wave dispersion imaging (SWD) and transient elastography (TE). Furthermore, liver steatosis was assessed using the controlled attenuation parameter (CAP) and compared to the new method of attenuation imaging (ATI). 29 AATD patients were enrolled, of which 18 had the PiZZ genotype, eight had PiMZ, two had PiSZ and one had a PiZP-Lowell genotype. 2D-SWE (median 1.42 m/S, range 1.14–1.83 m/S) and TE (median 4.8 kPa, range 2.8–24.6 kPa) values displayed a significant correlation (R = 0.475, p < 0.05). 2D-SWE, ATI (median 0.56 dB/cm/MHz, range 0.43–0.96 dB/cm/MHz) and CAP (median 249.5 dB/m, range 156–347 dB/m) values were higher in PiZZ when compared to other AATD genotypes. This study provides evidence that 2D-SWE is a suitable method for the assessment of liver disease in AATD. The newer methods of SWD and ATI require further evaluation in the context of AATD.