The influence of aminotransferase levels on liver stiffness assessed by Acoustic Radiation Force Impulse Elastography: a retrospective multicentre study

The Portal Venous Pulsatility Index and Main Portal Vein Diameter as Surrogate Markers for Liver Fibrosis in Nonalcoholic Fatty Liver Disease and Metabolic-Dysfunction-Associated Steatotic Liver Disease

(1) Background: Despite numerous noninvasive methods for assessing liver fibrosis, effective ultrasound parameters remain limited. We aimed to identify easily measurable ultrasound parameters capable of predicting liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) and metabolic-dysfunction-associated steatotic liver disease (MASLD); (2) Methods: The data of 994 patients diagnosed with NAFLD via ultrasound at the Armed Forces Goyang Hospital were retrospectively collected from June 2022 to July 2023. A liver stiffness measurement (LSM) ≥ 8.2 kPa was classified as significant fibrosis. Liver steatosis with cardiometabolic risk factors was defined as MASLD. Two ultrasound variables, the portal venous pulsatility index (VPI) and main portal vein diameter (MPVD), were measured; (3) Results: Of 994 patients, 68 had significant fibrosis. Significant differences in VPI (0.27 vs. 0.34, p < 0.001) and MPVD (10.16 mm vs. 8.98 mm, p < 0.001) were observed between the fibrotic and non-fibrotic groups. A logistic analysis adjusted for age and body mass index (BMI) revealed that only VPI (OR of 0.955, p = 0.022, VPI on a 0.01 scale) and MPVD (OR of 1.501, p < 0.001) were significantly associated with significant liver fibrosis. In the MASLD cohort (n = 939), VPI and MPVD were associated with significant fibrosis. To achieve better accuracy in predicting liver fibrosis, we established a nomogram that incorporated MPVD and VPI. The established nomogram was validated in the test cohort, yielding an area under the receiver operating characteristic curve of 0.821 for detecting significant liver fibrosis; (4) Conclusions: VPI and MPVD, as possible surrogate markers, are useful in predicting significant fibrosis in patients with NAFLD and MASLD.

How to Identify Advanced Fibrosis in Adult Patients with Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH) Using Ultrasound Elastography-A Review of the Literature and Proposed Multistep Approach

Non-alcoholic fatty liver disease (NAFLD), and its progressive form, non-alcoholic steatohepatitis (NASH), represent, nowadays, real challenges for the healthcare system. Liver fibrosis is the most important prognostic factor for NAFLD, and advanced fibrosis is associated with higher liver-related mortality rates. Therefore, the key issues in NAFLD are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. We critically reviewed the ultrasound (US) elastography techniques for the quantitative characterization of fibrosis, steatosis, and inflammation in NAFLD and NASH, with a specific focus on how to differentiate advanced fibrosis in adult patients. Vibration-controlled transient elastography (VCTE) is still the most utilized and validated elastography method for liver fibrosis assessment. The recently developed point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) techniques that use multiparametric approaches could bring essential improvements to diagnosis and risk stratification.

Nonalcoholic fatty liver disease and diabetes

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world and represents a clinical-histopathologic entity where the steatosis component may vary in degree and may or may not have fibrotic progression. The key concept of NAFLD pathogenesis is excessive triglyceride hepatic accumulation because of an imbalance between free fatty acid influx and efflux. Strong epidemiological, biochemical, and therapeutic evidence supports the premise that the primary pathophysiological derangement in most patients with NAFLD is insulin resistance; thus the association between diabetes and NAFLD is widely recognized in the literature. Since NAFLD is the hepatic manifestation of a metabolic disease, it is also associated with a higher cardio-vascular risk. Conventional B-mode ultrasound is widely adopted as a first-line imaging modality for hepatic steatosis, although magnetic resonance imaging represents the gold standard noninvasive modality for quantifying the amount of fat in these patients. Treatment of NAFLD patients depends on the disease severity, ranging from a more benign condition of nonalcoholic fatty liver to nonalcoholic steatohepatitis. Abstinence from alcohol, a Mediterranean diet, and modification of risk factors are recommended for patients suffering from NAFLD to avoid major cardiovascular events, as per all diabetic patients. In addition, weight loss induced by bariatric surgery seems to also be effective in improving liver features, together with the benefits for diabetes control or resolution, dyslipidemia, and hypertension. Finally, liver transplantation represents the ultimate treatment for severe nonalcoholic fatty liver disease and is growing rapidly as a main indication in Western countries. This review offers a comprehensive multidisciplinary approach to NAFLD, highlighting its connection with diabetes.

The Efficacy of Acoustic Radiation Force Impulse Elastography for Predicting Clinical Outcomes in Living Donor Liver Transplant

PURPOSE

Acoustic radiation force impulse (ARFI) elastography is widely used for evaluating liver fibrosis. Here we evaluated the efficacy of ARFI elastography for estimating graft quality and clinical outcomes in living donor liver transplant (LDLT).

METHODS

We retrospectively evaluated the cases of 87 LDLT donors who preoperatively underwent ARFI elastography at Nagasaki University Hospital between August 2010 and June 2016. We analyzed whether the velocity of shear wave (Vs) obtained by ARFI elastography affected the regeneration rate of each donor's remnant liver and the 1-year survival rate of the recipients.

RESULTS

There were no significant correlations between Vs value and the donors' age. Only 1 donor (1.1%) showed significant fibrosis, F2 (portal fibrosis with few septa) in zero-biopsy. The 7 donors (8.0%), including 1 case, showed a high Vs value (> 1.33) that was equal to F2, although there was no abnormal pathologic finding except in 1 case. In those cases, the regeneration rate of the remnant liver after hepatectomy was significantly lower compared to other cases. The 1-year survival rate of the recipients paired with the high-Vs donors was also significantly poorer than that of the other cases (high-Vs: 57.1%, others: 84.2%, P = .04).

CONCLUSIONS

ARFI elastography might be an effective examination for the preoperative evaluation of the graft quality in LDLT.

Evaluating short-term outcomes of the value of sound touch elastography (STE) following the treatment for Budd-Chiari syndrome (BCS): a case series study

AIM

To investigate the value of sound touch elastography (STE) in the evaluation of short-term therapeutic effect of Budd-Chiari syndrome (BCS) by measuring liver stiffness (LS), and in addition, to analyse the relationships between liver function, pressure gradient of the hepatic veins, and LS.

MATERIALS AND METHODS

A case series study was conducted at Affiliated Hospital of Xuzhou Medical University from August 2020 to December 2020. Patients diagnosed with BCS were recruited prospectively and grouped according to Child-Pugh grade before endovascular therapy. LS was measured using STE before and after therapy. Comparisons between the LS and hepatic venous pressure gradient (HVPG) changes of patients were tested with paired sample t-tests.

RESULTS

A total of 46 patients (23 males and 23 females) were included in this study. According to the Child-Pugh scoring criteria, 24 patients were classified as grade A, 16 as grade B, and 6 as grade C. LS was significantly different between the three groups (F = 127.01, p<0.001). Post-treatment LS was significantly lower than pre-treatment (p<0.001). The mean HVPG before treatment was 13.02 ± 3.82 mmHg and decreased after intervention (p<0.001).

CONCLUSION

The STE is a potential tool for evaluating short-term therapeutic effect of BCS patients.

Comparison between spleen and liver stiffness measurements by sound touch elastography for diagnosing cirrhosis at different aminotransferase levels: a prospective multicenter study

OBJECTIVES

To compare the performance of spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by sound touch elastography (STE) for the diagnosis of cirrhosis at different alanine aminotransferase (ALT) levels, and to compare the applicability and repeatability of SSM with LSM performed by STE, a new two-dimensional shear wave elastography technology.

METHODS

This prospective multicenter study included 25 centers and recruited chronic hepatitis B (CHB) patients with liver biopsy between May 2018 and November 2019. All patients underwent LSM and SSM by STE. Success and reliability rates were calculated and compared. Intra-observer agreement was assessed using intraclass correlation coefficients (ICCs). Differences between areas under the receiver operating characteristic curves (AUCs) of LSMs and SSMs at different ALT levels were compared using the Delong test.

RESULTS

Among 603 CHB patients, the success and reliability rates of SSM were 94.53% (570/603) and 85.74% (517/603), respectively, which were similar to those of LSM (p > 0.05), respectively. The ICC for intra-observer agreements of SSM was 0.964 (p < 0.001). In the total cohort, ALT ≤ 2 × upper limit of normal (ULN) group, and A0-1 group, the AUCs of SSMs were significantly lower than those of LSMs for the diagnosis of cirrhosis (p < 0.001). In the ALT > 2 × ULN group and A2-3 group, the AUC of SSM improved and was not significantly different from that of LSM (p = 0.342, p = 0.510, respectively).

CONCLUSIONS

SSM by STE achieved applicability and repeatability equivalent to those of LSM. SSM might be a good substitute to LSM in patients with high ALT levels.

KEY POINTS

• Spleen stiffness measurement performed by sound touch elastography was proven to have similar applicability and repeatability to liver stiffness measurement in this prospective multicenter study. • Spleen stiffness measurement demonstrated a poorer diagnostic performance for cirrhosis compared with liver stiffness measurement in the total cohort and low ALT level group, yet it showed a similar diagnostic performance to liver stiffness measurement in patients with high ALT levels.

Potential role of noninvasive biomarkers during liver fibrosis

Various types of liver disease exist, such as hepatitis and alcoholic liver disease. These liver diseases can result in scarring of liver tissue, cirrhosis, and finally liver failure. During liver fibrosis, there is an excess and disorganized accumulation of extracellular matrix (ECM) components which cause the loss of normal liver cell functions. For patients with chronic liver disease, fibrosis prediction is an essential part of the assessment and management. To diagnose liver fibrosis, several invasive and noninvasive markers have been proposed. However, the adoption of invasive markers remains limited due to their inherent characteristics and poor patient acceptance rate. In contrast, noninvasive markers can expedite the clinical decision through informed judgment about disease stage and prognosis. These noninvasive markers are classified into two types: Imaging techniques and serum biomarkers. However, the diagnostic values of biomarkers associated with liver fibrosis have also been analyzed. For example, the serum levels of ECM proteins can react to either matrix accumulation or degradation. During virus-host interactions, several regulatory steps take place to control gene expression, such as the change in cellular microRNA expression profiles. MicroRNAs are a class of non-coding RNAs (18-20 long nucleotides) that function by post-transcriptional regulation of gene expression. Although various noninvasive markers have been suggested in recent years, certain limitations have restricted their clinical applications. Understanding the potential of non-invasive biomarkers as a therapeutic option to treat liver fibrosis is still in progress.

Noninvasive Assessment of Hepatitis C Virus Infected Patients Using Vibration-Controlled Transient Elastography

Chronic infection with hepatitis C virus (HCV) is one of the leading causes of cirrhosis and hepatocellular carcinoma (HCC). Surveillance of these patients is an essential strategy in the prevention chain, including in the pre/post-antiviral treatment states. Ultrasound elastography techniques are emerging as key methods in the assessment of liver diseases, with a number of advantages such as their rapid, noninvasive, and cost-effective characters. The present paper critically reviews the performance of vibration-controlled transient elastography (VCTE) in the assessment of HCV patients. VCTE measures liver stiffness (LS) and the ultrasonic attenuation through the embedded controlled attenuation parameter (CAP), providing the clinician with a tool for assessing fibrosis, cirrhosis, and steatosis in a noninvasive manner. Moreover, standardized LS values enable proper staging of the underlying fibrosis, leading to an accurate identification of a subset of HCV patients that present a high risk for complications. In addition, VCTE is a valuable technique in evaluating liver fibrosis prior to HCV therapy. However, its applicability in monitoring fibrosis regression after HCV eradication is currently limited and further studies should focus on extending the boundaries of VCTE in this context. From a different perspective, VCTE may be effective in identifying clinically significant portal hypertension (CSPH). An emerging prospect of clinical significance that warrants further study is the identification of esophageal varices. Our opinion is that the advantages of VCTE currently outweigh those of other surveillance methods.

Severity of liver fibrosis using shear wave elastography is influenced by hepatic necroinflammation in chronic hepatitis patients, but not in cirrhotic patients

AIM

Shear wave elastography (SWE) in patients with chronic liver diseases is a noninvasive useful method for the diagnosis of liver fibrosis severity, which can be an alternative to liver biopsy. However, the liver stiffness measurement using SWE can be affected by various factors including hepatic inflammation, extrahepatic cholestasis, heart failure, and underlying liver diseases. The aim of this study is to clarify the correlation between liver stiffness using SWE and hepatic necroinflammation serologically and pathologically.

METHODS

A total of 843 patients with chronic liver disease who received liver biopsy were analyzed. Liver stiffness measurement using transient elastography (TE) and virtual touch quantification (VTQ) were carried out on the same day as the liver biopsy. The correlation between SWE and hepatic inflammation was analyzed serologically and pathologically.

RESULTS

The liver stiffness values increased significantly with the progression of liver fibrosis and inflammation (overall p < 0.001). In patients with F0-1, F2, and F3, TE and VTQ values of A2 or A3 were significantly higher than those of A0 or A1 (p value, all <0.05), but not in patients with F4. The median alanine aminotransferase (ALT) values increased significantly with the progression of liver inflammation (p < 0.001). Moreover, TE and VTQ in patients with ALT ≥70 IU/L were significantly higher than those in patients with ALT <70 IU/L (p < 0.01), but not in patients with F4.

CONCLUSION

Shear wave elastography can be affected by hepatic necroinflammation in F0-F3 fibrosis, but not in F4.

What's New in Hepatic Steatosis

Hepatic steatosis can lead to liver cancer, cirrhosis, and portal hypertension. There are two main types, non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. The detection and quantification of hepatic steatosis with lifestyle changes can slow the evolution from NAFLD to steatohepatitis. Currently, the gold standard for the quantification of fat in the liver is biopsy, has some limitations. Hepatic steatosis is frequently detected during cross sectional imaging. Ultrasound (US), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) provide noninvasive assessment of liver parenchyma and can detect fat infiltration in the liver. However, the non-invasive quantification of hepatic steatosis by imaging has been challenging. Recent MRI techniques show great promise in the detection and quantification of liver fat. The aim of this article is to review the utilization of non-invasive imaging modalities for the detection and quantification of hepatic steatosis, to evaluate their advantages and limitations.

Ultrasound-based liver elastography: current results and future perspectives

Chronic liver disease affects 185 million population worldwide. It encompasses a heterogenous disease spectrum, but all can lead to the development of liver fibrosis. The degree of liver fibrosis is not only a prognosticator, but has also been used to guide the treatment strategy and to evaluate treatment response. Traditionally, staging of liver fibrosis is determined on histological analysis using samples obtained from an invasive liver biopsy. Ultrasound-based liver elastography is a non-invasive method of assessing diffuse liver disease in patients with known chronic liver disease. The use of liver elastography has led to a significant reduction in the number of liver biopsies performed to assess the severity of liver fibrosis and a liver biopsy is now reserved for only select sub-groups of patients. The aim of this review article is to discuss the key findings and current evidence for ultrasound-based elastography in diffuse liver disease as well as the technical challenges and to evaluate the potential research direction.

Hepatic and splenic sonographic and sonoelastographic findings in pulmonary arterial hypertension

Purpose

The aim of this study was to evaluate the associations of sonographic and sonoelastographic parameters with clinical cardiac parameters, as well as to assess their value in predicting survival in patients with pulmonary arterial hypertension (PAH).

Methods

Thirty-six patients with PAH and normal liver function were prospectively enrolled in this prospective study along with 26 healthy controls, all of whom underwent ultrasound and point shear wave elastography examinations. Additionally, the portal vein pulsatility index (PVPI), inferior vena cava collapsibility index, and clinical cardiac variables were obtained in PAH patients. The values of hepatic (LV_s) and splenic shear wave velocity (SV_s) were compared between PAH patients and controls. The relationships between all sonographic and clinical parameters in the PAH patients were analyzed. Furthermore, their prognostic value in predicting survival was investigated.

Results

LV_s values in PAH patients (median, 1.62 m/s) were significantly higher than in controls (median, 0.99 m/s), while no significant difference was observed in SV_s values. Patients with higher grades of tricuspid regurgitation (TR) had significantly different values of PVPI (P=0.010) and sonoelastographic parameters (P<0.001 for LV_s and P=0.004 for SV_s) compared to those with less severe TR. Tricuspid annular plane systolic excursion values were the only investigated parameter found to be associated with survival (hazard ratio, 0.814; 95% confidence interval, 0.694 to 0.954; P=0.011).

Conclusion

Our results demonstrated a direct association between cardiac congestion (i.e., the severity of TR) and liver stiffness, which should be kept in mind during the assessment of fibrosis in patients with PAH.

Liver-related effects of chronic hepatitis C antiviral treatment

More than five years ago, the treatment of hepatitis C virus infection was revolutionized with the introduction of all-oral direct-acting antiviral (DAA) drugs. They proved highly efficient in curing patients with chronic hepatitis C (CHC), including patients with cirrhosis. The new DAA treatments were alleged to induce significant improvements in clinical outcome and prognosis, but the exact cause of the expected benefit was unclear. Further, little was known about how the underlying liver disease would be affected during and after viral clearance. In this review, we describe and discuss the liver-related effects of the new treatments in regards to both pathophysiological aspects, such as macrophage activation, and the time-dependent effects of therapy, with specific emphasis on inflammation, structural liver changes, and liver function, as these factors are all related to morbidity and mortality in CHC patients. It seems clear that antiviral therapy, especially the achievement of a sustained virologic response has several beneficial effects on liver-related parameters in CHC patients with advanced liver fibrosis or cirrhosis. There seems to be a time-dependent effect of DAA therapy with viral clearance and the resolution of liver inflammation followed by more discrete changes in structural liver lesions. These improvements lead to favorable effects on liver function, followed by an improvement in cognitive dysfunction and portal hypertension. Overall, the data provide knowledge on the several beneficial effects of DAA therapy on liver-related parameters in CHC patients suggesting short- and long-term improvements in the underlying disease with the promise of an improved long-term prognosis.

Two-dimensional shear wave elastography for significant liver fibrosis in patients with chronic hepatitis B: A systematic review and meta-analysis

PURPOSE

To determine the diagnostic performance and cutoff value of two-dimensional shear wave elastography (2D SWE) for detecting significant liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS

A systematic literature search of the PubMed, EMBASE, Cochrane Library databases and Web of Science was conducted. Bivariate modelling and summary receiver-operating-characteristic (ROC) modelling were constructed to summarize the diagnostic performance of 2D SWE. Meta-regression analyses were performed to explore the source of heterogeneity.

RESULTS

Eleven eligible studies with 2623 patients were included. 2D SWE showed a summary sensitivity of 88 % (95 % CI: 83-91), specificity of 83 % (95 % CI: 78-88) and area under the ROC curve of 0.92 (95 % CI: 0.89-0.94) for detecting significant fibrosis in CHB patients. The mean threshold of 2D SWE was 7.91 kPa (range: 6.73-10.00 kPa). Notably, the cutoffs of studies excluding patients with history of prior antiviral therapy were generally lower than that of studies without excluding those who had received antiviral treatment, with an average of 7.15 kPa and 8.87 kPa, respectively (p < 0.01). Meta-regression analysis revealed that enrollment of consecutive patients was the only significant factor influencing heterogeneity (p < 0.01). Specifically, studies recruiting consecutive patients with CHB had significantly lower sensitivity than those with absence of consecutive enrolment (0.83 vs 0.92, p < 0.01).

CONCLUSIONS

2D SWE is an excellent modality for predicting significant liver fibrosis in CHB populations. Further work is required to establish the cutoffs that account for antiviral treatment as a potential confounding factor.

Noninvasive diagnosis in alcohol-related liver disease

Background

Alcohol‐related liver disease (ALD) represents a major cause of death worldwide, and unfortunately, most patients are diagnosed at an advanced stage of the disease, which is related to poorer outcomes. Liver biopsy has historically been the gold standard for identifying advanced hepatic fibrosis, but this approach has several limitations, including invasiveness, low applicability, sampling variability, and cost.

Main Text

In order to detect earlier features of advanced liver fibrosis, surrogate biomarkers and techniques have been developed. While these were initially developed for chronic liver diseases such as viral hepatitis and nonalcoholic fatty liver disease (NAFLD), their performance in ALD has also been recently studied. Among the noninvasive surrogate markers and techniques used to detect liver fibrosis, the Enhanced Liver Fibrosis test, FibroTest, and Transient Elastography are the most accurate and validated techniques. In this review, we summarize the current status of the noninvasive assessment of liver disease in ALD and provide a synthesis of how these noninvasive tools can be used in clinical practice. Finally, we briefly outline novel biomarkers that are currently being investigated and discuss future directions and new opportunities in the noninvasive diagnosis of ALD.

Liver stiffness in chronic hepatitis C virus infection

INTRODUCTION

The severity of liver fibrosis can be assessed noninvasively today by liver stiffness measurements. Vibration-controlled transient elastography, shear wave elastography or magnetic resonance elastography are techniques increasingly used for this purpose.

METHODS

This article presents the recent advances in the use of new techniques for liver fibrosis assessment in chronic hepatitis C: the correlation between liver stiffness values and liver fibrosis estimated by liver biopsies, the prognosis role of liver stiffness values, their usefulness in monitoring the treatment response, in assessing the severity of portal hypertension and in estimating the presence of esophageal varices. Scientific articles from January 2017 to January 2018 were searched in PubMed and PubMed Central databases, using the terms "liver stiffness" and "hepatitis C".

RESULTS

The median liver stiffness values measured with different techniques are not identical, so that FibroScan thresholds cannot be used on any other elastographic machine. The higher the liver's stiffness measurement, the higher the liver-related events in patients with chronic hepatitis C. A liver stiffness measurement over 17 kPa could be an independent predictor for the presence of esophageal varices as well as a spleen with a longitudinal span ≥ 15 cm for patients with a value of liver stiffness < 17 kPa. A progressive and persistent decrease in liver stiffness is dependent on sustained virological response achievement. The lack of liver stiffness decrease has been associated with relapsers and a low value of liver stiffness at baseline.

CONCLUSION

Liver stiffness provides clues about the severity and evolution of liver disease.

Liver fibrosis imaging: A clinical review of ultrasound and magnetic resonance elastography

Liver fibrosis is a histological hallmark of most chronic liver diseases, which can progress to cirrhosis and liver failure, and predisposes to hepatocellular carcinoma. Accurate diagnosis of liver fibrosis is necessary for prognosis, risk stratification, and treatment decision-making. Liver biopsy, the reference standard for assessing liver fibrosis, is invasive, costly, and impractical for surveillance and treatment response monitoring. Elastography offers a noninvasive, objective, and quantitative alternative to liver biopsy. This article discusses the need for noninvasive assessment of liver fibrosis and reviews the comparative advantages and limitations of ultrasound and magnetic resonance elastography techniques with respect to their basic concepts, acquisition, processing, and diagnostic performance. Variations in clinical contexts of use and common pitfalls associated with each technique are considered. In addition, current challenges and future directions to improve the diagnostic accuracy and clinical utility of elastography techniques are discussed. Level of Evidence: 5 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:25-42.

Evaluation of Point Shear Wave Elastography Using Acoustic Radiation Force Impulse Imaging for Longitudinal Fibrosis Assessment in Patients with HBeAg-Negative HBV Infection

BACKGROUND

Accurate assessment of hepatic fibrosis in patients with chronic HBeAg-negative Hepatitis B is of crucial importance not only to predict the long-term clinical course, but also to evaluate antiviral therapy indication. The aim of this study was to prospectively assess the utility of point shear wave elastography (pSWE) for longitudinal non-invasive fibrosis assessment in a large cohort of untreated patients with chronic HBeAg-negative hepatitis B virus (HBV) infection.

METHODS

407 consecutive patients with HBeAg-negative HBV infection who underwent pSWE, transient elastography (TE) as well as laboratory fibrosis markers, including fibrosis index based on four factors (FIB-4), aspartate to platelet ratio index (APRI) and FibroTest, on the same day were prospectively followed up for six years. Patients were classified into one of the three groups: inactive carriers (IC; HBV-DNA <2000 IU/mL and ALT <40 U/L); grey zone group 1 (GZ-1; HBV DNA <2000 IU/mL and ALT >40 U/L); grey zone group 2 (GZ-2; HBV-DNA >2000 IU/mL and ALT <40 U/L).

RESULTS

pSWE results were significantly correlated with TE (r = 0.29, p < 0.001) and APRI (r = 0.17; p = 0.005). Median pSWE values did not differ between IC, GZ-1 and GZ-2 patients (p = 0.82, p = 0.17, p = 0.34). During six years of follow-up, median pSWE and TE values did not differ significantly over time (TE: p = 0.27; pSWE: p = 0.05).

CONCLUSION

Our data indicate that pSWE could be useful for non-invasive fibrosis assessment and follow-up in patients with HBeAg-negative chronic HBV infection.

Shear wave elastography correlates with liver fibrosis scores in pediatric patients with liver disease

BACKGROUND

While liver biopsy remains the gold standard, given the procedure risks and sampling errors, there is a need for reliable noninvasive biomarkers of hepatic fibrosis.

OBJECTIVE

Determine the accuracy of two-dimensional shear wave elastography (2-D SWE) in predicting the histological severity of liver fibrosis in pediatric patients with known or suspected liver disease.

MATERIALS AND METHODS

Subjects 0-18 years old with known or suspected liver disease and liver biopsy within 30 days (n=70) were included. Comparisons by 2-D SWE were made to a control group (n=79). Two-dimensional SWE was performed using the GE LOGIQ E9 system. Liver biopsy specimens were scored according to METAVIR and Ishak scoring systems using Spearman's Rho correlation. Receiver operator characteristic (ROC) analysis, Kruskal-Wallis and Mann-Whitney U tests were conducted.

RESULTS

Control group median 2-D SWE measurements were lower than in subjects with any degree of liver fibrosis (P<0.001). Those with METAVIR F0 and Ishak 0 scores had significantly lower median 2-D SWE measurements (1.35 m/s; 1.36 m/s) than those with more advanced liver disease (F1-F3: 1.49-1.62 m/s; 1-4: 1.45-1.63 m/s) (P<0.05 for all), whereas the 2-D SWE in the higher scores were similar. Results did not differ between METAVIR and Ishak scores for any degree of fibrosis. Fibrosis scores moderately correlated with median 2-D SWE measurements (r_s=0.43). The area under the curve for F1 compared to combined control/F0 was 0.89 (95% confidence interval [CI] 0.83-0.95; P<0.001) with sensitivity of 94.6% and specificity of 78.6%. Results for Ishak score 1 were similar. The ideal cutoff value for identifying fibrosis was determined to be 1.29 m/s.

CONCLUSION

The liver 2-D SWE measurements correlated with the histological liver fibrosis scores, regardless of the histopathological scoring system, although 2-D SWE was better at identifying patients with early fibrosis, not at distinguishing among the individual fibrosis levels. Two-dimensional SWE using the GE LOGIQ US system is useful for identifying pediatric patients at risk for liver fibrosis.

Diagnostic accuracy of acoustic radiation force impulse elastography (ARFI) in comparison to other non-invasive modalities in staging of liver fibrosis in chronic HCV patients: single-center experience

PURPOSE

To evaluate the reliability of ARFI elastography for liver fibrosis staging and compare it to other non-invasive assessment of hepatic fibrosis (FIB-4 and APRI) in chronic HCV (CHC) patients.

METHODS

A single-center, prospective study included 2103 CHC patients. Liver stiffness (LS) was evaluated by TE and ARFI elastography. FIB-4 and APRI were calculated. The area under the receiver-operating characteristic curve (AUROCs) was used to assess the diagnostic performance of ARFI elastography for staging of liver fibrosis using TE as a reference standard.

RESULTS

The best cut off values of ARFI elastography for diagnosis of ≥ F2, ≥ F3and F4 were 1.36 m/s, 1.45 m/s, and 1.7 m/s with AUROCs of 0.89, 0.94 and 0.95, respectively. ARFI elastography cut offs are lower in patients with normal ALT level compared to those with ALT level (1.1-< 3 ULN) and those with ALT level ≥ 3ULN (1.35 m/s vs 1.39 m/s vs 1.54 for F ≥ 2, 1.44 m/s vs 1.58 m/s vs 1.6 m/s for F3, 1.69 m/s, 1.84 m/s, 1.86 m/s for F4). FIB-4 (0.82-0.86) and APRI (0.78-0.82) yielded lower AUC in prediction of significant fibrosis and cirrhosis than ARFI elastography (0.89-0.95).

CONCLUSION

ARFI elastography is a reliable method for non-invasive staging of liver fibrosis in CHC patients when compared to TE with a good diagnostic performance comparable to FIB-4 and APRI scores for the prediction of significant fibrosis and cirrhosis.

Liver Ultrasound Elastography: An Update to the World Federation for Ultrasound in Medicine and Biology Guidelines and Recommendations

The World Federation for Ultrasound in Medicine and Biology has produced these guidelines for the use of elastography techniques in liver diseases. For each available technique, the reproducibility, results and limitations are analyzed, and recommendations are given. This set of guidelines updates the first version, published in 2015. Since the prior guidelines, there have been several advances in technology. The recommendations are based on the international published literature, and the strength of each recommendation is judged according to the Oxford Centre for Evidence-Based Medicine. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.

Current status of imaging in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldwide prevalence of 20% to 46%. NAFLD can be subdivided into simple steatosis and nonalcoholic steatohepatitis. Most cases of simple steatosis are non-progressive, whereas nonalcoholic steatohepatitis may result in chronic liver injury and progressive fibrosis in a significant minority. Effective risk stratification and management of NAFLD requires evaluation of hepatic parenchymal fat, fibrosis, and inflammation. Liver biopsy remains the current gold standard; however, non-invasive imaging methods are rapidly evolving and may replace biopsy in some circumstances. These methods include well-established techniques, such as conventional ultrasonography, computed tomography, and magnetic resonance imaging and newer imaging technologies, such as ultrasound elastography, quantitative ultrasound techniques, magnetic resonance elastography, and magnetic resonance-based fat quantitation techniques. The aim of this article is to review the current status of imaging methods for NAFLD risk stratification and management, including their diagnostic accuracy, limitations, and practical applicability.

Real-time shear wave elastography (SWE) assessment of short- and long-term treatment outcome in Budd-Chiari syndrome: A pilot study

Purpose

The first aim of this study was to analyze the relationships between liver stiffness measurement, hepatic venous pressure and liver fibrosis. The second aim was to demonstrate the utility of real-time shear wave elastography for evaluation of Budd-Chiari syndrome patients before and after balloon hepatic venous angioplasty.

Materials and methods

A total of 32 patients with Budd-Chiari syndrome slated for successful balloon angioplasty met the inclusion and exclusion criteria. Shear wave elastography was used to generate dynamic liver stiffness measurement 2 days before angioplasty and 2 days, 3 months, and 6 months after angioplasty. Hepatic venous pressures were measured during balloon angioplasty. Correlations among liver stiffness, hepatic venous pressure, and fibrosis were assessed.

Result

Mean liver stiffness was 35.17 ± 10.60 kPa, 20.15 ± 5.47 kPa, 15.36 ± 4.34 kPa and 15.68 ± 5.58 kPa at baseline and 2 days, 3 months, and 6 months after angioplasty, respectively. Liver stiffness measured at 2 days and 3 months after angioplasty was significantly decreased (P < 0.001); liver stiffness measured at 6 months after angioplasty was not significantly different from that measured at 3 months after angioplasty (P = 0.636). Analysis of liver stiffness measurement and hepatic venous pressure before balloon angioplasty yielded a coefficient of correlation r = 0.701 (P < 0.001). Before and 2d after angioplasty, liver stiffness measurement did not correlated with fibrosis (r = − 0.170, P = 0.22), (r = 0.223, P = 0.220), respectively, while the LSM difference before and 2 days after angioplasty negatively correlated with stiffness severity (r = − 0.502, P = 0.003). Liver stiffness measured at 2 days and 3 months after angioplasty was significantly decreased (P < 0.001), remaining stable at 3 months, though still in the cirrhotic range.

Conclusions

The liver stiffness of Budd-Chiari syndrome patients, measured by shear wave elastography, decreased considerably after hepatic venous recanalization, and significantly correlated with hepatic venous pressure though not with degree of fibrosis. Shear wave elastography may be effective in monitoring short- and long-term treatment outcomes in Budd-Chiari syndrome.

Acoustic Radiation Force Impulse Elastography in Post-transplant Recurrent Hepatitis C in Living Donor Liver Transplantation

OBJECTIVE

The aim of the study was to evaluate the efficacy of liver fibrosis (LF) with acoustic radiation force impulse (ARFI) elastography for post-transplant (post-LT) HCV recurrence.

PATIENTS AND METHODS

We enrolled 89 adult recipients of living donor liver transplantation (LDLT) who had HCV, with or without post-LT HCV recurrence and treated or not treated. The post-LT HCV recurrence was diagnosed on the basis of RNA viral load present. ARFI examination was performed every 3 months for all patients, with shear wave velocity (SWV) obtained quantitatively in m/s and correlated with histopathologic fibrosis scoring of liver biopsy (LB).

RESULTS

There were 50 (50 of 89) patients without HCV recurrence and 39 (39 of 89) with post-LT recurrence in the 89 patients studied. The recurrent group had significantly higher median SWVs (1.87 ± 0.52 vs 1.37 ± 0.52 m/s, P < .0001), in which 18 (18 of 39) patients had antiviral drug treatment and obtained significant improvement with SWVs from 1.83 ± 0.49 to 1.68 ± 0.56 m/s, P = .043. The correlations of LF staging between ARFI elastography and Ishak histopathologic LF scores showed great significance, P = .045. The HCV RNA titer after antiviral treatment decreased from 3,831,750 to 0, P < .0001, but the RNA titer of nontreated patients remained high and the median SWV increased. The Ishak LF staging in the nontreated group progressed from stage 1 to 2, P = .012 and SWV increased from 1.69 ± 0.54 to 1.91 ± 0.66 m/s, P = .085 at 1-year follow-up.

CONCLUSION

ARFI elastography has efficient quantitative LF monitoring correlated with histopathologic staging for post-LT HCV recurrence. It could be an alternative, noninvasive method for frequent LB in the disease follow-up.

Ultrasound findings in autoimmune hepatitis

Ultrasound findings in autoimmune hepatitis (AIH) have not been reported systematically so far. The use of reliable and accurate noninvasive methods for determining fibrosis stage is important in evaluation of treatment efficacy and fibrosis regression in AIH. Imaging plays an important role in detection of complications and ruling out other possible causes of chronic liver diseases. Ultrasound elastography cut-off values in AIH patients are not the same as those in patients with chronic viral hepatitis or non-alcoholic fatty liver disease. AIH is characterized by wide fluctuations in inflammatory activity. Here we report on current knowledge of ultrasound findings in AIH.

Usefulness of virtual touch quantification for staging liver fibrosis in patients with hepatitis C, and factors affecting liver stiffness measurement failure compared with liver biopsy

AIM

The assessment of liver fibrosis in patients with hepatitis C is important to predict carcinogenesis. In this study, we evaluated the usefulness of virtual touch quantification (VTQ) for staging liver fibrosis, and investigated factors causing discrepancies between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

METHODS

Patients with hepatitis C (n = 302) were assessed using VTQ and underwent pathological liver investigation within 1 week before and after VTQ. A receiver operator characteristic (ROC) curve was obtained for VTQ, fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio index (APRI), and each area under the ROC curve (AUROC) was compared to predict fibrosis stage. We used univariate and multivariate analyses to investigate the factors related to the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

RESULTS

At any stage, VTQ was the most accurate for staging liver fibrosis. The VTQ cut-off values were 1.33 m/s (AUROC = 0.822) for ≥F2, 1.51 m/s (AUROC = 0.836) for ≥F3, and 1.92 m/s (AUROC = 0.890) for F4. Skin liver capsule distance (SCD) was the most relevant factor for the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. The SCD cut-off value was 17.5 mm.

CONCLUSIONS

Virtual touch quantification is a non-invasive, simple method that is more accurate for staging liver fibrosis than the FIB-4 index and APRI. However, when the SCD is longer than 17.5 mm, there may be measurement failures.

PET/CT with 18F Fluorocholine as an Imaging Biomarker for Chronic Liver Disease: A Preliminary Radiopathologic Correspondence Study in Patients with Liver Cancer

Purpose To determine the relationship between hepatic uptake at preoperative fluorine 18 (¹⁸F) fluorocholine combined positron emission tomography (PET) and computed tomography (CT) and the histopathologic features of chronic liver disease in patients with Child-Pugh class A or B disease who are undergoing hepatic resection for liver cancer. Materials and Methods Forty-eight patients with resectable liver tumors underwent preoperative ¹⁸F fluorocholine PET/CT. Mean liver standardized uptake value (SUV_mean) measurements were obtained from PET images, while histologic indexes of inflammation and fibrosis were applied to nontumor liver tissue from resection specimens. Effects of histopathologic features on liver SUV_mean were examined with analysis of variance. Results Liver SUV_mean ranged from 4.3 to 11.6, correlating significantly with Knodell histologic activity index (ρ = -0.81, P < .001) and several clinical indexes of liver disease severity. Liver SUV_mean also differed significantly across groups stratified by necroinflammatory severity and Metavir fibrosis stage (P < . 001). The area under the receiver operating characteristic curve for ¹⁸F fluorocholine PET/CT detecting Metavir fibrosis stage F1 or higher was 0.89 ± 0.05, with an odds-ratio of 3.03 (95% confidence interval: 1.59, 5.88) and sensitivity and specificity of 82% and 93%, respectively. Conclusion Correlations found in patients undergoing hepatic resection for liver cancer between liver ¹⁸F fluorocholine uptake and histopathologic indexes of liver fibrosis and inflammation support the use of ¹⁸F fluorocholine PET/CT as a potential imaging biomarker for chronic liver disease. ^© RSNA, 2018.

Liver stiffness reduction correlates with histological characteristics of hepatitis C patients with sustained virological response

BACKGROUND & AIMS

We investigated the correlation between histological characteristics and changes in liver stiffness (LS) in patients with sustained virological response (SVR) using acoustic radiation force impulse (ARFI) elastography.

METHODS

In this prospective study, we enrolled 176 hepatitis C patients with SVR who underwent ARFI elastography and liver biopsy before antiviral treatment, and serial ARFI elastography at the end of treatment (EOT) and at 24 weeks after the EOT. To compare the long-term changes in LS in patients with SVR using ARFI elastography, another group of 140 patients who had undergone paired biopsy after achieving SVR was included.

RESULTS

Mean LS values were 1.60±0.63 m/s, 1.48±0.56 m/s and 1.37±0.62 m/s at baseline, EOT and 24 weeks after EOT, respectively, P<.001. Higher inflammatory activity at baseline was associated with an improvement in LS at the EOT, with an odds ratio of 1.940. Significant fibrosis at baseline was associated with an improvement in LS at 24 weeks after the EOT, with an odds ratio of 2.617. Among patients in the paired biopsy group with baseline fibrosis stage identical to the ARFI group, LS values at 24 weeks after the EOT did not show any difference with values at 5 years after EOT.

CONCLUSIONS

Pre-treatment histological characteristics influence LS reduction after SVR is achieved.

Liver stiffness measurement predicts hepatocellular carcinoma development in patients treated with direct-acting antivirals

BACKGROUND AND AIM

Predictive factors for hepatocarcinogenesis following eradication of hepatitis C virus by direct-acting antivirals (DAAs) are unknown. The aim of the study was to investigate the relationships between liver stiffness (LS) using acoustic radiation force impulse (ARFI) erastograghy and the development of hepatocellular carcinoma (HCC) in patients who achieved sustained virological response (SVR) treated with DAA.

METHODS

In this prospective study, we enrolled 263 hepatitis C patients with SVR who underwent ARFI before DAA treatment. Thirty patients had previous HCC.

RESULTS

The median LS value according to ARFI measurements was 1.34 m/s (range: 0.67-4.35). During the follow-up period (median: 18.1 months), development of HCC occurred in 19 patients (7.2%; HCC occurrence in 7 patients and HCC recurrence in 12 patients). By multivariate Cox regression analysis, HCC history (hazard ratio [HR]: 10.634; 95% confidence interval [CI]: 4.13-27.37; P = 0.001), older age (HR: 4.638; 95% CI: 1.63-13.61; P = 0.004) and higher total bilirubin levels (HR: 4.189; 95% CI: 1.66-10.60; P = 0.002) were independent predictors for the development of HCC, and higher LS value (≥1.73 m/s) at baseline was an independent predictor for HCC occurrence (HR: 8.350; 95% CI: 1.62-43.09; P = 0.011). The cumulative recurrence of HCC was statistically similar according to the degree of LS in patients who were previously treated for HCC.

CONCLUSION

The LS value at baseline is useful for predicting HCC occurrence. Thus, even if SVR is achieved, patients with higher LS at baseline must be followed carefully for HCC occurrence.

American Gastroenterological Association Institute Technical Review on the Role of Elastography in Chronic Liver Diseases

Chronic liver diseases (CLDs), due to chronic hepatitis C; hepatitis B; nonalcoholic fatty liver diseases (NAFLD); and alcoholic liver disease, are a leading cause of morbidity and mortality globally. Early identification of patients with cirrhosis at high risk of progression to liver-related complications may facilitate timely care and improve outcomes. With risks and misclassification associated with invasive tests, such as liver biopsy, noninvasive imaging modalities for liver fibrosis assessment have gained popularity. Therefore, the American Gastroenterological Association prioritized clinical guidelines on the role of elastography in CLDs, focusing on vibration-controlled transient elastography (VCTE) and magnetic resonance elastography (MRE). To inform these clinical guidelines, the current technical review was developed in accordance with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework for diagnostic accuracy studies. This technical review addresses focused questions related to: (1) comparative diagnostic performance of VCTE and MRE relative to nonproprietary, serum-based fibrosis markers for detection of cirrhosis in patients with hepatitis C virus (HCV), hepatitis B virus (HBV), NAFLD, and alcoholic liver diseases; (2) performance of specific VCTE-defined liver stiffness cutoffs as a test replacement strategy (to replace liver biopsy) in making key decisions in the management of patients with CLDs; and (3) performance of specific VCTE-defined liver stiffness cutoffs as a triage test to identify patients with low likelihood of harboring high-risk esophageal varices (EVs) or having clinically significant portal hypertension (for presurgical risk stratification). This technical review does not address performance of other noninvasive modalities for assessing fibrosis (eg, acoustic radiation force pulse imaging or shear wave elastography) or steatosis (controlled attenuation parameter or magnetic resonance imaging-estimated proton density fat fraction).

Two-dimensional Shear-Wave Elastography Performance in the Noninvasive Evaluation of Liver Fibrosis in Patients with Chronic Hepatitis B: Comparison with Serum Fibrosis Indexes

Purpose To investigate the value of two-dimensional (2D) shear-wave elastography (SWE) in the assessment of hepatic fibrosis in patients with chronic hepatitis B (CHB) and to compare the diagnostic performance of this modality with that of liver fibrosis indexes. Materials and Methods The ethics committee approved this study, and informed consent was obtained. From July 2015 to May 2016, 539 subjects who underwent partial hepatectomy were divided into groups according to the Scheuer system by using a resected liver specimen. All patients were examined with 2D SWE and underwent preoperative serologic testing to measure liver stiffness and values of serum fibrosis models, which were compared with histologic findings. Performance of noninvasive methods was determined for index (304 patients) and validation (155 patients) cohorts by using areas under the receiver operating characteristic curve (AUCs). Results For association with substantial fibrosis (≥S2), severe fibrosis (≥S3), and cirrhosis (S4) in the index cohort, the optimal cutoff values of liver stiffness were 7.6, 9.2, and 10.4 kPa, respectively, and AUC values were 0.97, 0.96, and 0.98, respectively. The 2D SWE findings, aspartate transaminase-to-platelet ratio index (APRI), fibrosis index based on the four factors (FIB-4), King's score, and Forns index significantly correlated with hepatic fibrosis stages (ρ = 0.88, ρ = 0.41, ρ = 0.40, ρ = 0.43 and ρ = 0.45, respectively; P < .05). The AUCs for APRI, FIB-4, King's score, and Forns index were 0.77, 0.73, 0.79, and 0.77, respectively, in the diagnosis of substantial fibrosis and 0.70, 0.71, 0.72, and 0.74, respectively, in the diagnosis of cirrhosis. In the validation cohort, AUCs of noninvasive methods used to assess different fibrosis stages did not significantly differ from those for the index cohort. AUCs of 2D SWE in the diagnosis of substantial fibrosis, severe fibrosis, and cirrhosis were 0.97, 0.97, and 0.98, respectively, which were significantly higher than those in serum models (P < .05). Conclusion The 2D SWE protocol could be used to predict substantial fibrosis, severe fibrosis, and cirrhosis in patients with CHB with notably higher diagnostic accuracy than that attained with serum fibrosis models. ^© RSNA, 2016.

Regression of fibrosis and portal hypertension in HCV-associated cirrhosis and sustained virologic response after interferon-free antiviral therapy

It is still controversial, whether and to what amount cirrhosis and portal hypertension are reversible in patients with hepatitis C virus (HCV)-associated cirrhosis and sustained virologic response (SVR) after interferon-free antiviral therapy. In this study, we prospectively evaluated dynamics of liver and spleen stiffness in HCV-infected patients with advanced liver disease and SVR after interferon-free treatment. A total of 54 patients with HCV-associated cirrhosis and SVR were included. Liver and spleen stiffness was measured at therapy baseline (BL), end of treatment (EOT) and 24 weeks after EOT (FU24) by transient liver elastography (L-TE) as well as by acoustic radiation force impulse of the liver (L-ARFI) and spleen (S-ARFI), as well as biochemical, virologic and clinical data. Improvement of liver and spleen stiffness was found in 44 of 50 (88%), 31 of 54 (57%) and 25 of 54 (46%) of patients assessed by L-TE, L-ARFI and S-ARFI between baseline and FU24. Liver stiffness assessed by L-TE improved between BL [median (range), 32.5 (9.1-75) kPa] and EOT [median (range), 21.3 (6.7-73.5) kPa; (P<.0001)], and between BL and FU24 [median (range), 21.2 (5.4-70) kPa; (P<.0001)]. Liver stiffness assessed by L-ARFI improved between BL [median (range), 2.7 (1.2-4.1) m/s] and FU24 [median (range), 2.4 (1.2-3.9) m/s; P=.002), while spleen stiffness remained unchanged. Our data suggest that improvement of liver stiffness may be rather due to reduced necroinflammation and may be due to a less extent to regression of cirrhosis, as dynamics of liver stiffness improvement was more pronounced between BL and EOT than BL and FU24.

Targeting Hepatic Fibrosis in Autoimmune Hepatitis

Hepatic fibrosis develops or progresses in 25 % of patients with autoimmune hepatitis despite corticosteroid therapy. Current management regimens lack reliable noninvasive methods to assess changes in hepatic fibrosis and interventions that disrupt fibrotic pathways. The goals of this review are to indicate promising noninvasive methods to monitor hepatic fibrosis in autoimmune hepatitis and identify anti-fibrotic interventions that warrant evaluation. Laboratory methods can differentiate cirrhosis from non-cirrhosis, but their accuracy in distinguishing changes in histological stage is uncertain. Radiological methods include transient elastography, acoustic radiation force impulse imaging, and magnetic resonance elastography. Methods based on ultrasonography are comparable in detecting advanced fibrosis and cirrhosis, but their performances may be compromised by hepatic inflammation and obesity. Magnetic resonance elastography has excellent performance parameters for all histological stages in diverse liver diseases, is uninfluenced by inflammatory activity or body habitus, has been superior to other radiological methods in nonalcoholic fatty liver disease, and may emerge as the preferred instrument to evaluate fibrosis in autoimmune hepatitis. Promising anti-fibrotic interventions are site- and organelle-specific agents, especially inhibitors of nicotinamide adenine dinucleotide phosphate oxidases, transforming growth factor beta, inducible nitric oxide synthase, lysyl oxidases, and C-C chemokine receptors types 2 and 5. Autoimmune hepatitis has a pro-fibrotic propensity, and noninvasive radiological methods, especially magnetic resonance elastography, and site- and organelle-specific interventions, especially selective antioxidants and inhibitors of collagen cross-linkage, may emerge to strengthen current management strategies.

ARFI: from basic principles to clinical applications in diffuse chronic disease-a review

Abstract

The many factors influencing the shear wave velocity (SWV) measured with Acoustic Radiation Force Impulse (ARFI) are examined in order to define the most correct examination technique. In particular, attention is given to the information achieved by experimental models, such as phantoms and animal studies. This review targets the clinical applications of ARFI in the evaluation of chronic diffuse disease, especially of liver and kidneys. The contribution of ARFI to the clinical workout of these patients and some possible perspectives are described.

Teaching Points

• Stiffness significantly varies among normal and abnormal biological tissues.

• In clinical applications physical, geometrical, anatomical and physiological factors influence the SWV.

• Elastographic techniques can quantify fibrosis, which is directly related to stiffness.

• ARFI can be useful in chronic diffuse disease of liver and kidney.

Added value of point shear-wave elastography in the diagnosis of acute cholecystitis

OBJECTIVE

To evaluate the added value of point shear-wave elastography (pSWE) in the diagnostic performance of conventional US for diagnosis of acute cholecystitis.

METHODS

B-mode and colour Doppler US and pSWE were performed prospectively in 216 patients with clinically suspected acute cholecystitis. The morphology and mural vascularity of the gallbladder and median shear wave velocity (SWV) of the right liver were evaluated. Two observers independently reviewed conventional US images and subsequently reviewed combined conventional US and pSWE images.

RESULTS

Mean SWVs of the acute cholecystitis group (n = 91) were significantly higher than those of the control group (n = 85) in the right liver within 2 cm lateral to the gallbladder (1.56 versus 1.03 m/s, 1.39 versus 1.04 m/s, P < 0.0001) with a cut-off value of 1.29 or 1.16 m/s. The area under the receiver operating characteristic curve of both observers in the diagnosis of acute cholecystitis improved significantly from 0.790 and 0.777 to 0.963 and 0.962, respectively, after additional review of pSWE images (P < 0.0001). Diagnostic accuracy, sensitivity, specificity, positive and negative predictive values of combined image sets were higher than those of conventional US images alone.

CONCLUSION

Adding pSWE to conventional US improves the diagnosis of acute cholecystitis when compared with conventional US alone.

KEY POINTS

• In acute cholecystitis, stiffness of the right liver increases adjacent to the gallbladder. • The cut-off value for diagnosing acute cholecystitis was 1.29 or 1.16 m/s. • Adding pSWE to conventional US improves the diagnosis of acute cholecystitis.

Liver stiffness measurement using acoustic radiation force impulse elastography in hepatitis C virus-infected patients with a sustained virological response

BACKGROUND

Acoustic radiation force impulse (ARFI) elastography is a non-invasive method for measuring liver stiffness. However, there are no reports evaluating the value of ARFI elastography for liver fibrosis in chronic hepatitis C patients with a sustained virological response (SVR).

AIM

To investigate the diagnostic performance of ARFI elastography for the assessment of liver fibrosis in hepatitis C virus (HCV) infected patients with an SVR.

METHODS

In this prospective study, we enrolled 336 patients: 121 HCV patients with an SVR (44.6% women) and 215 patients with HCV (47.9% women). ARFI elastography measurements of all patients were performed on the same day of liver biopsy.

RESULTS

The diagnostic accuracies, expressed as areas under the receiver operating characteristic curves for ARFI elastography, in HCV patients with an SVR and those in patients with HCV were 0.818 and 0.875 for the diagnosis of significant fibrosis (≥F2), 0.909 and 0.888 for the diagnosis of severe fibrosis (≥F3), and 0.981 and 0.890 for the diagnosis of liver cirrhosis (F4), respectively. The optimum cut-off values for ARFI elastography were 1.26 m/s for ≥F2, 1.31 m/s for ≥F3 and 1.49 m/s for F4 in HCV patients with an SVR. The liver stiffness values were lower in patients with SVR compared with those in patients with HCV at the same stage of fibrosis. The liver stiffness values were affected by the necroinflammatory activity and the time after SVR.

CONCLUSION

Acoustic radiation force impulse elastography is an acceptable method for predicting the severity of fibrosis in patients with hepatitis C virus and a sustained viral response.

Non-invasive Markers of Liver Fibrosis: Adjuncts or Alternatives to Liver Biopsy?

Liver fibrosis reflects sustained liver injury often from multiple, simultaneous factors. Whilst the presence of mild fibrosis on biopsy can be a reassuring finding, the identification of advanced fibrosis is critical to the management of patients with chronic liver disease. This necessity has lead to a reliance on liver biopsy which itself is an imperfect test and poorly accepted by patients. The development of robust tools to non-invasively assess liver fibrosis has dramatically enhanced clinical decision making in patients with chronic liver disease, allowing a rapid and informed judgment of disease stage and prognosis. Should a liver biopsy be required, the appropriateness is clearer and the diagnostic yield is greater with the use of these adjuncts. While a number of non-invasive liver fibrosis markers are now used in routine practice, a steady stream of innovative approaches exists. With improvement in the reliability, reproducibility and feasibility of these markers, their potential role in disease management is increasing. Moreover, their adoption into clinical trials as outcome measures reflects their validity and dynamic nature. This review will summarize and appraise the current and novel non-invasive markers of liver fibrosis, both blood and imaging based, and look at their prospective application in everyday clinical care.

Time Harmonic Elastography Reveals Sensitivity of Liver Stiffness to Water Ingestion

The aim of the study was to test the sensitivity of liver stiffness (LS) measured by time harmonic elastography in large tissue windows to water uptake and post-prandial effects. Each subject gave written informed consent to participate in this institutional review board-approved prospective study. LS was measured by time harmonic elastography in 10 healthy volunteers pre- and post-prandially, as well as before, directly after and 2 h after drinking water. The LS-time function during water intake was measured in 14 scans over 3 h in five volunteers. LS increased by 10% (p = 0.0015) post-prandially and by 11% (p = 0.0024) after pure water ingestion, and decreased to normal values after 2 h. LS was lower after overnight fasting than after 2-h fasting (3%, p = 0.04). Over the time course, LS increased to post-water peak values 15 min after drinking 0.25 L water and remained unaffected by further ingestion of water. In conclusion, our study indicates that LS measured by time harmonic elastography represents an effective-medium property sensitive to physiologic changes in vascular load of the liver.

Elastography for the pancreas: Current status and future perspective

Elastography for the pancreas can be performed by either ultrasound or endoscopic ultrasound (EUS). There are two types of pancreatic elastographies based on different principles, which are strain elastography and shear wave elastography. The stiffness of tissue is estimated by measuring the grade of strain generated by external pressure in the former, whereas it is estimated by measuring propagation speed of shear wave, the transverse wave, generated by acoustic radiation impulse (ARFI) in the latter. Strain elastography is difficult to perform when the probe, the pancreas and the aorta are not located in line. Accordingly, a fine elastogram can be easily obtained in the pancreatic body but not in the pancreatic head and tail. In contrast, shear wave elastography can be easily performed in the entire pancreas because ARFI can be emitted to wherever desired. However, shear wave elastography cannot be performed by EUS to date. Recently, clinical guidelines for elastography specialized in the pancreas were published from Japanese Society of Medical Ultrasonics. The guidelines show us technical knacks of performing elastography for the pancreas.

Fibroscan improves the diagnosis sensitivity of liver fibrosis in patients with chronic hepatitis B

The aim of the present study was to investigate the diagnostic accuracy of Fibroscan for liver fibrosis in patients with chronic hepatitis B (CHB) with alanine aminotransferase (ALT) levels <2 times the upper normal limit. A total of 263 consecutive patients with CHB and ALT levels <2 times the upper normal limit were enrolled in the present study. Liver biopsies and liver stiffness measurements (LSM) were conducted. Receiver operating characteristic (ROC) analysis was used to determine the predictive ability of LSM for the development of liver fibrosis in patients with stage S1, S2 and S3 liver fibrosis. Bivariate Spearman rank correlation analysis was performed in order to determine the association between liver stiffness value, which was measured by Fibroscan, and liver fibrosis stage, which was measured by liver biopsy. The liver stiffness value was found to be positively correlated with the liver fibrosis stage (r=0.522, P<0.001) and necroinflammatory activity (r=0.461, P<0.001), which was measured by liver biopsy. The optimal cut-off value in the patients with stage S1, S2 and S3 liver fibrosis was 5.5, 8.0 and 10.95 kPa, respectively. The area under the ROC curve for the prediction of the development of liver fibrosis in these patients was 0.696, 0.911 and 0.923, respectively. The threshold of the optimal cut-off value exhibited a high sensitivity and specificity. The results of the present study suggested that Fibroscan may improve the sensitivity of the diagnosis of liver fibrosis in patients with CHB and ALT levels <2 times the upper normal limit, and that this sensitivity may increase with the progression of liver fibrosis.

Ultrasound elastography: liver

Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.

Non-invasive assessment of liver fibrosis in patients with alcoholic liver disease using acoustic radiation force impulse elastography

OBJECTIVES

To investigate the diagnostic performance of the acoustic radiation force impulse (ARFI) elastography for the assessment of the liver fibrosis in alcoholic liver disease (ALD).

METHODS

We included 112 patients with ALD in whom liver biopsy, ARFI elastography, and aspartate-to-platelet ratio index (APRI) measurements were performed.

RESULTS

ARFI elastography correlated significantly with histological fibrosis (r = 0.685, P < 0.001) in patients with ALD. The diagnostic accuracies expressed as areas under receiver operating characteristic (AUROC) curves for ARFI elastography and APRI were 0.846 and 0.763 for the diagnosis of significant fibrosis (S ≥ 2), 0.875 and 0.688 for the diagnosis of severe fibrosis (S ≥ 3), and 0.893 and 0.648 for the diagnosis of liver cirrhosis, respectively. The AUROC values of ARFI elastography were significantly better than those of APRI for predicting severe fibrosis (P = 0.02) and cirrhosis (P = 0.04). The optimum cutoff values for ARFI elastography were 1.33 m/s for S ≥ 2, 1.40 m/s for S ≥ 3, and 1.65 m/s for S = 4 in patients with elevated alanine aminotransferase (ALT) levels; these decreased to 1.24 m/s for S ≥ 2, 1.27 m/s for S ≥ 3, and 1.41 m/s for S = 4 in patients with normal ALT.

CONCLUSION

ARFI elastography is an acceptable method for predicting the severity of fibrosis in patients with ALD. ARFI elastography is influenced by elevated aminotransferase levels in ALD.

Head-to-Head Comparison between Collagen Proportionate Area and Acoustic Radiation Force Impulse Elastography in Liver Fibrosis Quantification in Chronic Hepatitis C

BACKGROUND

The aim of this study was to compare the diagnostic performances of the collagen proportionate area (CPA) and liver stiffness measurement (LSM) for liver fibrosis quantification in chronic hepatitis C (CHC).

METHODS

A total of 137 eligible consecutive Taiwanese patients (74 women and 63 men; age 21-80 years; median age 54 years), with CHC underwent LSM by using acoustic radiation force impulse (ARFI) elastography and an immediate percutaneous liver biopsy for METAVIR scoring. Liver tissue sections were stained using picrosirius red. Areas of the stained collagen and the tissue parenchyma were calculated in pixels. The ratio between the two areas was expressed as a CPA percentage. The result of LSM was presented as shear wave velocity (SWV).

RESULTS

METAVIR fibrosis (F) stages were dichotomized using the CPA (%) and SWV (m/s), and the optimal cut-off values were 7.47 and 1.59 for F1 versus F2-4; 12.56 and 1.73 for F1, 2 versus F3, 4; 15.32 and 1.96 for F1-3 versus F4. To dichotomize F1 versus F2-4, the areas under receiver operating characteristic curves for the CPA was 0.9349 (95% confidence interval: 0.8943-0.9755) and for SWV was 0.8434 (0.7762-0.9105) (CPA versus SWV, P = 0.0063). For F1, 2 versus F3, 4, the CPA was 0.9436 (0.9091-0.9781); SWV was 0.8997 (0.8444-0.9551) (P = 0.1587). For F1-3 versus F4, the CPA was 0.8647 (0.7944-0.9349); SWV was 0.9036 (0.8499-0.9573) (P = 0.2585). The CPA could be predicted in a linear regression formula by using SWV and platelet count (R2 = 0.524).

CONCLUSIONS

The CPA and ARFI elastography are promising tools for liver fibrosis evaluation. The CPA was superior to ARFI elastography in the diagnosis of significant fibrosis (≥ F2). The CPA may be independent of severe necroinflammation, which may augment liver stiffness.

Head-to-Head Comparison between Collagen Proportionate Area and Acoustic Radiation Force Impulse Elastography in Liver Fibrosis Quantification in Chronic Hepatitis C

BACKGROUND

The aim of this study was to compare the diagnostic performances of the collagen proportionate area (CPA) and liver stiffness measurement (LSM) for liver fibrosis quantification in chronic hepatitis C (CHC).

METHODS

A total of 137 eligible consecutive Taiwanese patients (74 women and 63 men; age 21-80 years; median age 54 years), with CHC underwent LSM by using acoustic radiation force impulse (ARFI) elastography and an immediate percutaneous liver biopsy for METAVIR scoring. Liver tissue sections were stained using picrosirius red. Areas of the stained collagen and the tissue parenchyma were calculated in pixels. The ratio between the two areas was expressed as a CPA percentage. The result of LSM was presented as shear wave velocity (SWV).

RESULTS

METAVIR fibrosis (F) stages were dichotomized using the CPA (%) and SWV (m/s), and the optimal cut-off values were 7.47 and 1.59 for F1 versus F2-4; 12.56 and 1.73 for F1, 2 versus F3, 4; 15.32 and 1.96 for F1-3 versus F4. To dichotomize F1 versus F2-4, the areas under receiver operating characteristic curves for the CPA was 0.9349 (95% confidence interval: 0.8943-0.9755) and for SWV was 0.8434 (0.7762-0.9105) (CPA versus SWV, P = 0.0063). For F1, 2 versus F3, 4, the CPA was 0.9436 (0.9091-0.9781); SWV was 0.8997 (0.8444-0.9551) (P = 0.1587). For F1-3 versus F4, the CPA was 0.8647 (0.7944-0.9349); SWV was 0.9036 (0.8499-0.9573) (P = 0.2585). The CPA could be predicted in a linear regression formula by using SWV and platelet count (R2 = 0.524).

CONCLUSIONS

The CPA and ARFI elastography are promising tools for liver fibrosis evaluation. The CPA was superior to ARFI elastography in the diagnosis of significant fibrosis (≥ F2). The CPA may be independent of severe necroinflammation, which may augment liver stiffness.

Contemporary use of elastography in liver fibrosis and portal hypertension

The risk and speed of progression from fibrosis to compensated and decompensated cirrhosis define the prognosis in liver diseases. Therefore, early detection and preventive strategies affect outcomes. Patients with liver disease have traditionally been diagnosed at an advanced stage of disease, in part due to lack of non-invasive markers. Ultrasound elastography to measure liver stiffness can potentially change this paradigm. The purpose of this review was therefore to summarize advances in the field of ultrasound elastography with focus on diagnosis of liver fibrosis, cirrhosis and clinically significant portal hypertension, techniques and limitations. Four types of ultrasound elastography exist, but there is scarce evidence comparing the different techniques. The majority of experience concern transient elastography for diagnosing fibrosis and cirrhosis in patients with chronic viral hepatitis C. That said, the role of elastography in other aetiologies such as alcoholic- and non-alcoholic liver fibrosis still needs clarification. Although elastography can be used to diagnose liver fibrosis and cirrhosis, its true potential lies in the possibility of multiple, repeated measurements that allow for treatment surveillance, continuous risk stratification and monitoring of complications. As such, elastography may be a powerful tool for personalized medicine. While elastography is an exciting technique, the nature of ultrasound imaging limits its applicability, due to the risk of failures and unreliable results. Key factors that limit the applicability of liver stiffness measurements are as follows: liver vein congestion, cholestasis, a recent meal, inflammation, obesity, observer experience and ascites. The coming years will show whether elastography will be widely adapted in general care.