Factors associated with unreliable liver stiffness measurement and its failure with transient elastography in the Chinese population

Current Modalities of Fibrosis Assessment in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a burgeoning global health concern. In the subset of NAFLD patients with non-alcoholic steatohepatitis (NASH), the presence of significant fibrosis at index assessment is associated with poor prognosis and increased mortality. Hence, there is a growing need to accurately assess and stage fibrosis. Liver biopsy, the current gold standard, has limitations with sampling error and is invasive, with associated inherent risk. This has led to a host of non-invasive means of assessing fibrosis, which has garnered relevance in a disease that requires serial assessment of fibrosis longitudinally over time. This review discusses, comprehensively, the various tools available to the clinician for the assessment of fibrosis, including the various scoring systems used in liver biopsy, the non-invasive means of serum biomarkers, such as the highly-validated NAFLD fibrosis score, and the imaging-based modalities, such as transient elastography and magnetic resonance elastography.

Th17/Treg imbalance is an indicator of liver cirrhosis process and a risk factor for HCC occurrence in HBV patients

OBJECTIVE

To determine the impact of T helper 17 cell (Th17)/regulatory T cell (Treg) ratio imbalance on the process and prognosis of hepatitis B virus (HBV)-related liver cirrhosis.

METHODS

Patients with HBV who refused to accept any therapy from were recruited from 2009 to 2014 and followed-up to August 2016. Based on a liver stiffness measurement (LSM), the patients were divided into a low LSM group and a high LSM group. After propensity score matching, 150 patients were included. The peripheral blood of all subjects was tested using a flow cytometer to measure the Th17 and Treg cell frequencies and the Th17/Treg ratio. Spearman rank correlation, log-rank test, Cox regression model, and receiver operating characteristic (ROC) curves were applied to analyze the correlation between the Th17/Treg ratio and LSM level and the risk factors of HCC occurrence and to predict the Th17/Treg ratio for the LSM level.

RESULTS

Th17 and Treg cell frequencies and the Th17/Treg ratio were significantly different between the low and high LSM groups. The Th17/Treg ratio showed a strong positive association with LSM level (r=0.631, P<0.01). Furthermore, the Th17/Treg ratio was an independent factor influencing the HCC occurrence, which was tested using a Cox regression model. The area under the ROC curve of the Th17/Treg ratio for predicting LSM level was 0.783 (95% CI 0.705-0.861).

CONCLUSION

Th17/Treg ratio imbalance is an indicator of the liver cirrhosis process and a risk factor for HCC occurrence in patients infected with HBV.

Enhanced liver fibrosis test using ELISA assay accurately discriminates advanced stage of liver fibrosis as determined by transient elastography fibroscan in treatment naïve chronic HCV patients

Evaluation of liver fibrosis stage is crucial in the assessment of chronic HCV patients, regarding decision to start treatment and during follow-up. Our aim was to assess the validity of the enhanced liver fibrosis (ELF) score in discrimination of advanced stage of liver fibrosis in naïve chronic HCV patients. We prospectively evaluated liver fibrosis stage in one hundred eighty-one naïve chronic HCV Egyptian patients by transient elastography (TE)-FibroScan. Patients were categorized into mild to moderate fibrosis (≤F2) group and advanced fibrosis (≥F3) group. The ELF score components, hyaluronic acid (HA), amino-terminal propeptide of type-III-procollagen (PIIINP) and tissue inhibitor of metalloproteinase type-1 (TIMP-1), were done using ELISA test. The mean values of ELF and its individual components significantly correlated with the hepatic fibrosis stage as measured by TE-FibroScan (P value 0.001). ELF cutoff value of 9.8 generated a sensitivity of 77.8%, specificity of 67.1%, area under the receiver operator characteristic curve (AUROC) of 0.76 with 95% confidence interval [CI] (0.68-0.83) for detecting advanced fibrosis (F ≥ 3). ELF panel is a good, reliable noninvasive test and showed comparable results to TE-FibroScan in detecting liver fibrosis stage in treatment naïve chronic HCV patients.

Liver fibrosis staging with a new 2D-shear wave elastography using comb-push technique: Applicability, reproducibility, and diagnostic performance

Objective

To evaluate the applicability, reproducibility, and diagnostic performance of a new 2D-shear wave elastography (SWE) using the comb-push technique (2D CP-SWE) for detection of hepatic fibrosis, using histopathology as the reference standard.

Materials and methods

This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. The liver stiffness (LS) measurements were obtained from 140 patients, using the new 2D-SWE, which uses comb-push excitation to produce shear waves and a time-aligned sequential tracking method to detect shear wave signals. The applicability rate of 2D CP-SWE was estimated, and factors associated with its applicability were identified. Intraobserver reproducibility was evaluated in the 105 patients with histopathologic diagnosis, and interobserver reproducibility was assessed in 20 patients. Diagnostic performance of the 2D CP-SWE for hepatic fibrosis was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

The applicability rate of 2D CP-SWE was 90.8% (109 of 120). There was a significant difference in age, presence or absence of ascites, and the distance from the transducer to the Glisson capsule between the patients with applicable LS measurements and patients with unreliable measurement or technical failure. The intraclass correlation of interobserver agreement was 0.87, and the value for the intraobserver agreement was 0.95. The area under the ROC curve of LS values for stage F2 fibrosis or greater, stage F3 or greater, and stage F4 fibrosis was 0.874 (95% confidence interval [CI]: 0.794–0.930), 0.905 (95% CI: 0.832–0.954), and 0.894 (95% CI: 0.819–0.946), respectively.

Conclusion

2D CP-SWE can be employed as a reliable method for assessing hepatic fibrosis with a reasonably good diagnostic performance, and its applicability might be influenced by age, ascites, and the distance between the transducer and Glisson capsule.

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

Chronic hepatitis B virus (HBV) infection is a major cause of liver morbidity and mortality worldwide. While a proportion of the 250 million individuals chronically infected with HBV will not come to significant harm or require therapy, many others risk developing complications of the end-stage liver disease such as decompensated cirrhosis and hepatocellular carcinoma (HCC), without intervention. Due to the complex natural history of HBV infection, patients require an expert assessment to interpret biochemistry, viral serology and appropriately stage the disease, and to initiate monitoring and/or therapy where indicated. The detection and quantification of liver fibrosis is a key factor for disease management and prognostication for an individual with HBV. The reliance on invasive liver biopsy to stage disease is diminishing with the advent of robust non-invasive blood- and imaging-based algorithms which can reliably stage disease in many cases. These tests are now incorporated into International guidelines for HBV management and relied upon daily to inform clinical judgement. Both blood- and imaging-based approaches have advantages over liver biopsy, including minimal risks, lower cost, better patient acceptance and speed of results, while disadvantages include lower diagnostic accuracy in intermediate disease stages and variability with co-existing hepatic inflammation or steatosis. This review outlines the methods of fibrosis assessment in chronic HBV infection and focuses on the most commonly used blood- and imaging-based non-invasive tests, reviewing their diagnostic performance and applicability to patient care.

Noninvasive imaging methods to determine severity of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is now the most common form of liver disease in developed countries, with an estimated prevalence of 20%-30% and increasing to as high as 90% in diabetics. As the rates of NAFLD continue to rise in parallel with those of the obesity pandemic, it is increasingly important to differentiate those patients with the highest risk of progression to fibrosis and cirrhosis. In fact, those patients with nonalcoholic steatohepatitis (NASH) and fibrosis are at the greatest risk of progression to advanced disease, cirrhosis, and hepatocellular cancer and are more likely to develop liver-related mortality. Thus, it is critically important to distinguish between NASH and non-NASH NAFLD. Whereas liver biopsy remains the gold standard for staging of disease, complications of this procedure and other well-recognized limitations make it impractical for widespread use given the overall NAFLD disease burden. Noninvasive imaging modalities are increasingly being utilized to evaluate and stage NAFLD in patients with such a wide spectrum of disease. In this article, the role of these new and promising noninvasive imaging modalities to assess disease severity in NAFLD are reviewed. (Hepatology 2016;64:2234-2243).

Perioperative Non-Invasive Indocyanine Green-Clearance Testing to Predict Postoperative Outcome after Liver Resection

Background

Postoperative liver dysfunction may lead to morbidity and mortality after liver resection. Preoperative liver function assessment is critical to identify preexisting liver dysfunction in patients prior to resection. The aim of this study was to evaluate the predictive potential of perioperative indocyanine green (ICG)-clearance testing to prevent postoperative liver dysfunction and morbidity using standardized outcome parameters in a routine Western-clinical-setting.

Study Design

137 patients undergoing partial hepatectomy between 2011 and 2013, at the general hospital of Vienna, were included. ICG-clearance was recorded one day prior to surgery as well as on the first and fifth postoperative day. Postoperative liver dysfunction was defined according to the International Study Group of Liver Surgery and evaluation of morbidity was based on the Dindo-Clavien classification. Statistical analyses were based on non-parametric tests.

Results

Preoperative reduced ICG—plasma disappearance rate (PDR) as well as increased ICG—retention rate at 15 min (R15) were able to significantly predict postoperative liver dysfunction (Area under the curve = PDR: 0.716, P = 0.018; R15: 0.719, P = 0.016). Furthermore, PDR <17%/min. or R15 >8%, were able to accurately predict postoperative complications prior to surgery. In addition to this, ICG-clearance on postoperative day 1 comparably predicted postoperative liver dysfunction (Area under the curve = PDR: 0.895; R15: 0.893; both P <0.001), specifically, PDR <10%/min or R15 >20% on postoperative day 1 predicted poor postoperative outcome.

Conclusion

PDR and R15 may represent useful parameters to distinguish preoperative high and low risk patients in a Western collective as well as on postoperative day 1, to identify patients who require closer monitoring for potential complications.

Transient elastography in healthy subjects and factors influencing liver stiffness in non-alcoholic fatty liver disease: An Italian community-based population study

BACKGROUND

Few studies have been performed to explore parameters that influence liver stiffness measurement (LSM) using transient elastography in general population.

AIM

To explore factors influencing LSM in healthy and in subjects with non-alcoholic fatty liver disease (NAFLD).

METHODS

LSM was performed in a well-characterized cohort of subjects aged between 30 and 63 years. After exclusion of any causes of liver disease, the healthy cohort was defined and was compared with participants with NAFLD. The 95th percentile value of LSM in healthy was used as a cutoff suggesting relevant fibrosis.

RESULTS

Among 780 subjects evaluated, 331 were defined as healthy. The median value was 4.4kPa (3.7-5.2) and the 95th percentile was 6.8kPa. LSM was not influenced by gender, age, anthropometrics and biochemical parameters. Only insulin resistance was independently associated with increasing of LSM. In the cohort of 157 subjects with NAFLD, LSM was higher than in healthy (5.6±1.9 vs 4.6±1.3kPa; p<0.001). On multivariate analysis, the degree of steatosis was independently associated with increasing of LSM in NAFLD cohort (β=0.271; 95% CI=0.026-0.095; p<0.001). Participants with diabetes and/or severe steatosis had the highest probabilities of relevant fibrosis.

CONCLUSIONS

LSM varies between 3.7 and 5.2kPa in healthy Caucasians and is influenced only by insulin resistance. In NAFLD, severe steatosis and diabetes are factors influencing LSM.

Feasibility of liver stiffness measurement in morbidly obese patients undergoing bariatric surgery using XL probe

OBJECTIVE

Prevalence of non-alcoholic fatty liver disease is rising in the Western world and reaches up to 90% in patients undergoing bariatric surgery. Fibroscan(®) as a non-invasive tool for liver stiffness measurement (LSM) has several limitations in morbidly obese patients. Only few data exist about the technical feasibility and accuracy of LSM in these patients. We aimed to analyse the feasibility of LSM by Fibroscan(®) in bariatric patients.

MATERIALS AND METHODS

In morbidly obese patients, LSM was performed using XL probe. Measurements were termed reliable if 10 successful measurements with a success rate ≥60% and an interquartile range/median (IQR/M) <0.3 were obtained, unreliable if 10 successful measurements were obtained but the IQR/M was >0.3, and they were termed failed if they were neither reliable nor unreliable.

RESULTS

A total of 149 patients were included (87 with liver biopsies); mean BMI was 51.6 ± 8.5 kg/m(2). In 41% LSM using XL-probe was reliable, in 22% unreliable and in 37% failed. Failed LSM was significantly more frequent in patients with higher BMI compared to reliable and unreliable measurements (p < 0.05). In patients with failed measurement, sonographic paramedian and intercostal distances were significantly higher compared to reliable measurements. All three patients with F4 fibrosis could successfully be differentiated by LSM from patients without fibrosis.

CONCLUSIONS

LSM with XL probe is feasible in almost two-thirds of morbidly obese patients with a BMI ≥50 kg/m(2). Reliable prediction of advanced fibrosis appears to be possible even if formal criteria of successful measurements are not met.

Reliability and applicability of two-dimensional shear-wave elastography for the evaluation of liver stiffness

BACKGROUND/AIM

Two-dimensional shear-wave elastography (2D-SWE) is a new elastographic technique that is increasingly being used across several indications. We assessed the reliability and applicability of 2D-SWE in patients with various chronic liver diseases and attempted to identify parameters potentially affecting liver stiffness.

METHODS

We included all patients with chronic liver disease who underwent 2D-SWE examination over a 15-month period. Patients with acute hepatitis, active cholestatic disease, or severe heart failure were excluded. The procedures were performed by three adequately trained operators. Standard operating procedures for liver ultrasonography and elastography were followed.

RESULTS

2D-SWE was reliable in 98% of 605 patients. SD to mean liver stiffness value ratio greater than 9.14%, which was considered an indicator of reliability, was associated independently with age more than 50 years, obesity, or overweight, and use of statins for hyperlipidemia. 2D-SWE was applicable, requiring a median time of 7 min per examination and exceeding 15 min in only 5.5% of patients. Worse applicability expressed as duration more than 0.7 min per reliable measurement was associated independently with age more than 50 years and obesity. The mean and median liver stiffness values were 11.6 and 7.7 kPa, respectively. Liver stiffness more than 7.7 kPa was associated independently with age more than 50 years and increased waist circumference.

CONCLUSION

2D-SWE represents an applicable method of assessment of liver fibrosis that can provide reliable results in the vast majority of patients with chronic liver diseases. Older age and obesity may affect the reliability and applicability of the method as well as the severity of liver fibrosis.

Screening diabetic patients for non-alcoholic fatty liver disease with controlled attenuation parameter and liver stiffness measurements: a prospective cohort study

OBJECTIVE

Type 2 diabetes is an important risk factor for non-alcoholic fatty liver disease (NAFLD), but current guidelines provide conflicting recommendations on whether diabetic patients should be screened for NAFLD. We therefore studied the strategy of screening diabetic patients by FibroScan.

DESIGN

Liver fat and fibrosis were assessed by controlled attenuation parameter (CAP) and liver stiffness measurements (LSM) by FibroScan at a diabetic centre for patients from primary care and hospital clinics. Probe-specific LSM cut-offs were used to detect advanced fibrosis.

RESULTS

Of 1918 patients examined, 1799 (93.8%) had valid CAP and 1884 (98.2%) had reliable LSM (1770 with the M probe and 114 with the XL probe). The proportion of patients with increased CAP and LSM was 72.8% (95% CI 70.7% to 74.8%) and 17.7% (95% CI 16.0% to 19.5%), respectively. By multivariable analysis, female gender, higher body mass index, triglycerides, fasting plasma glucose and alanine aminotransferase (ALT) and non-insulin use were associated with increased CAP. Longer duration of diabetes, higher body mass index, increased ALT and spot urine albumin:creatinine ratio and lower high-density lipoprotein-cholesterol were associated with increased LSM. Ninety-four patients (80% had increased LSM) underwent liver biopsy: 56% had steatohepatitis and 50% had F3-4 disease.

CONCLUSIONS

Diabetic patients have a high prevalence of NAFLD and advanced fibrosis. Those with obesity and dyslipidaemia are at particularly high risk and may be the target for liver assessment. Our data support screening for NAFLD and/or advanced fibrosis in patients with type 2 diabetes.

Real-time elastography as a noninvasive assessment of liver fibrosis in chronic hepatitis C Egyptian patients: a prospective study

BACKGROUND

Hepatitis C virus is a worldwide problem. Noninvasive methods for liver fibrosis assessment as ultrasound-based approaches have emerged to replace liver biopsy. The aim of this study was to evaluate the diagnostic accuracy of real-time elastography (RTE) in the assessment of liver fibrosis in patients with chronic hepatitis C (CHC), compared with transient elastography and liver biopsy.

METHODS

RTE, FibroScan and liver biopsy were performed in 50 CHC patients. In addition, aspartate aminotransferase to platelet ratio index (APRI) and routine laboratory values were included in the analysis.

RESULTS

RTE was able to diagnose significant hepatic fibrosis (F ≥2) according to METAVIR scoring system at cut-off value of 2.49 with sensitivity 100%, specificity 66%, and area under the receiver-operating characteristics (AUROC) 0.8. FibroScan was able to predict significant fibrosis at cut-off value 7.5 KPa with sensitivity 88%, specificity 100%, and AUROC 0.94.APRI was able to predict significant hepatic fibrosis (F ≥2) with sensitivity 54%, specificity 80%, and AUROC 0.69. There was a significant positive correlation between the FibroScan score and RTE score (r=0.6, P=0.001).

CONCLUSIONS

Although FibroScan is superior in determining significant hepatic fibrosis, our data suggest that RTE may be a useful and promising noninvasive method for liver fibrosis assessment in CHC patients especially in cases with technical limitations for FibroScan.

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.

Biopsy and Noninvasive Methods to Assess Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of histopathologic features, ranging from isolated hepatic steatosis, to steatohepatitis with evidence of hepatocellular injury and fibrosis, to cirrhosis. The diagnosis and determination of NAFLD prognosis requires clinical and histopathologic assessments. Liver biopsy still is regarded as the reference for differentiating steatosis (NAFL) from nonalcoholic steatohepatitis, for staging hepatic fibrosis, and for identifying NAFLD in patients with other chronic liver disease. Standardized grading and staging histologic scoring systems, such as the NAFLD activity score and the steatosis, activity, and fibrosis score, can help guide clinical decisions and assess outcomes of clinical trials. Improved understanding of the pathophysiology of NAFLD and technologic advances have led to algorithms that can be used to assess serum biomarkers and imaging methods that are noninvasive alternatives to biopsy collection and analysis. We review the advantages and limitations of biopsy analysis and noninvasive tests as diagnostic and prognostic tools for patients with NAFLD. We also discuss techniques to improve dynamic histopathology assessment, and emerging blood and imaging biomarkers of fibrogenesis.

Impact of skin capsular distance on the performance of controlled attenuation parameter in patients with chronic liver disease

BACKGROUND & AIMS

Controlled attenuation parameter (CAP) is a non-invasive method for evaluating hepatic steatosis. However, larger skin capsular distance (SCD) can affect the accuracy. The aim of this study was to investigate the impact of SCD on the diagnostic performance of CAP and liver stiffness measurement (LSM).

METHODS

Of 101 patients with non-alcoholic fatty liver disease (NAFLD) and 280 patients with chronic hepatitis B (CHB) who underwent liver biopsy were prospectively recruited. CAP, LSM and SCD were performed using FibroScan with M probe. The areas under receiver operating characteristics curves (AUROCs) were calculated to determine the diagnostic efficacy. The optimal thresholds were defined by the maximum Youden index.

RESULTS

SCD (B 30.34, P < 0.001) and hepatic steatosis (B 23.04, P < 0.001) were independently associated with CAP by multivariate analysis. The AUROCs were slightly higher for SCD <25 mm compared to those for SCD ≥25 mm for steatosis ≥5% (0.88 vs. 0.81), >33% (0.90 vs. 0.85) and >66% (0.84 vs. 0.72). For SCD <25 mm, the optimal CAP cut-offs for differentiating steatosis ≥5%, >33% and >66% were 255.0 dB/m, 283.5 dB/m and 293.5 dB/m. However, cut-offs were elevated by approximately 60-70 dB/m for SCD ≥25 mm. When stratified by fibrosis grade, LSM was significantly affected by SCD ≥25 mm for advanced fibrosis (≥F3) in NAFLD, but not in CHB.

CONCLUSION

CAP is a promising tool for detecting and quantifying hepatic steatosis. SCD ≥25 mm may cause overestimation of steatosis. Similarly, SCD ≥25 mm affects the detection of advanced fibrosis by LSM in NAFLD patients.

Transient Elastography-Based Liver Profiles in a Hospital-Based Pediatric Population in Japan

Background & Aims

The utility of transient elastography (FibroScan) is well studied in adults but not in children. We sought to assess the feasibility of performing FibroScans and the characteristics of FibroScan-based liver profiles in Japanese obese and non-obese children.

Methods

FibroScan examinations were performed in pediatric patients (age, 1–18 yr) who visited Osaka City University Hospital. Liver steatosis measured by controlled attenuation parameter (CAP), and hepatic fibrosis evaluated as the liver stiffness measurement (LSM), were compared among obese subjects (BMI percentile ≥90%), non-obese healthy controls, and non-obese patients with liver disease.

Results

Among 214 children examined, FibroScans were performed successfully in 201 children (93.9%; median, 11.5 yr; range, 1.3–17.6 yr; 115 male). CAP values (mean±SD) were higher in the obese group (n = 52, 285±60 dB/m) compared with the liver disease (n = 40, 202±62, P<0.001) and the control (n = 107, 179±41, P<0.001) group. LSM values were significantly higher in the obese group (5.5±2.3 kPa) than in the control (3.9±0.9, P<0.001), but there were no significant differences in LSM between the liver disease group (5.4±4.2) and either the obese or control group. LSM was highly correlated with CAP in the obese group (ρ = 0.511) but not in the control (ρ = 0.129) or liver disease (ρ = 0.170) groups.

Conclusions

Childhood obesity carries a high risk of hepatic steatosis associated with increased liver stiffness. FibroScan methodology provides simultaneous determination of CAP and LSM, is feasible in children of any age, and is a non-invasive and effective screening method for hepatic steatosis and liver fibrosis in Japanese obese children.

Increased abdominal fat levels measured by bioelectrical impedance are associated with histological lesions of nonalcoholic steatohepatitis

BACKGROUND/AIM

Abdominal fat is considered to play an important role in nonalcoholic fatty liver disease (NAFLD), although it is not adequately studied because abdominal fat levels cannot be estimated easily. In this study, associations between abdominal obesity, as assessed by abdominal bioelectrical impedance analysis (BIA), and the characteristics of patients with NAFLD were explored.

PATIENTS AND METHODS

Seventy-four consecutive NAFLD patients who underwent measurement of abdominal fat levels by BIA were included. Levels of abdominal fat 12.5 or less and more than 12.5 were considered to be average and increased, respectively.

RESULTS

The mean±SD BMI was 30±4 kg/m and the mean abdominal fat levels were 16±5, whereas 26% of patients had average abdominal fat levels. Patients with average compared with those with increased abdominal fat levels were more frequently women (50 vs. 12%, P=0.001), had lower BMI (27±3 vs. 31±4 kg/m, P<0.001), lower Homeostasis Model Assessment index (2.6±1.4 vs. 3.9±2.7, P=0.045), and lower median liver stiffness on transient elastography (5.3 vs. 6.8 kPa, P=0.025). In patients with available liver biopsy, steatohepatitis was present more frequently in patients with increased compared with average abdominal fat levels (78 vs. 38%, P=0.030) and in patients with BMI 30 or more compared with less than 30 kg/m (87 vs. 48%, P=0.033), but similar in patients with increased or normal waist circumference (67 vs. 56%, P=0.693).

CONCLUSION

Average levels of abdominal fat, as assessed by abdominal BIA, are mainly present in female patients with NAFLD and are associated with a lower degree of insulin resistance. Increased abdominal fat as assessed by BIA and obesity seem to represent strong risk factors for histological steatohepatitis.

Hepatic MR Elastography: Clinical Performance in a Series of 1377 Consecutive Examinations

PURPOSE

To assess the technical success rate and diagnostic performance of liver magnetic resonance (MR) elastography.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board with patient informed consent. A total of 1377 consecutive MR elastography examinations performed between 2007 and 2010 in 1287 patients for clinical indications were included. Medical records were used to retrieve liver stiffness as assessed with MR elastography, histologic analysis, blood work, and other liver disease-related information. Nonparametric Kruskal-Wallis tests and analysis of covariance methods were used to evaluate the diagnostic values and relationships of the collected data.

RESULTS

Hepatic MR elastography had a success rate of 94.4% (1300 of 1377 cases) and yielded reproducible measurements (r = 0.9716, P < .0001) in the study cohort, with a complex patient profile and multiple interpreters. Body mass index had no significant effect on success rate (P = .2). In 289 patients who underwent liver biopsy within 1 year of the MR elastography date, mean liver stiffness as assessed with MR elastography was significantly higher in patients with advanced fibrosis (stages F3, F4) than in those with mild to moderate fibrosis (stages F0, F1, F2) (5.93 kPa ± 2.31 [standard deviation] vs 3.35 kPa ± 1.44, P < .0001). Liver stiffness is associated with many factors other than fibrosis extent, including cause of fibrosis (viral hepatitis C vs nonalcoholic fatty liver disease, P = .025), inflammation (severe vs mild to moderate, P = .03), and hepatic metabolic and synthetic function (no fibrosis vs intermediate fibrosis, P ≤ .01).

CONCLUSION

In a general clinical practice environment, hepatic MR elastography is a robust imaging method with a high success rate in a broad spectrum of patients. It also shows the complex association between liver stiffness and hepatic pathophysiology.

Longer duration of transient elastography predicts unreliable liver stiffness measurements

BACKGROUND

Transient elastography (TE) is a noninvasive, validated method to assess liver fibrosis by obtaining liver stiffness measurements (LSM). However, TE can be limited by unreliable measurement (UM). The relationship between the time taken to perform TE (duration) and UM has not been studied.

OBJECTIVES

To determine whether the duration of TE correlates with UM.

MATERIALS AND METHODS

We prospectively studied the frequency and predictors of UM over a 5-year period. UM was defined as follows: less than 10 successful measurements, success rate less than 60%, or interquartile range more than 30% of the median LSM value (IQR/LSM>30%).

RESULTS

Among the 2834 patients with LSM analysed, UM occurred in 19.0%. Duration [odds ratio (OR) 4.2, 95% confidence interval (CI) 2.8-6.4; P<0.0001] was the strongest predictor of UM, followed by BMI more than 28 kg/m (OR 2.1, 95% CI 1.5-3.0; P<0.0001), age more than 52 (OR 1.6, 95% CI 1.1-2.3; P=0.007) and non-HBV aetiology (OR 1.6, 95% CI 1.1-2.3; P=0.02). An optimal cut-off of 3 min 47 s was calculated for predicting UM (sensitivity 70%, specificity 65%, OR 4.2, 95% CI 2.7-6.6, P<0.0001). Examinations that took longer than 8 min 10 s had a 90% chance of UM.

CONCLUSION

In experienced hands, duration is a strong predictor of UM in patients undergoing TE. Examinations longer than 4 min are more likely to be unreliable. Examinations longer than 8 min are unlikely to yield a valid result and should be considered a futility endpoint. Older age and increased BMI and nonhepatitis B aetiology are independent, albeit weaker, predictors of UM.

Noninvasive imaging assessment of non-alcoholic fatty liver disease: Focus on liver scintigraphy

Noninvasive diagnoses of nonalcoholic fatty-liver disease (NAFLD) involve the use of serologic markers and imaging methods, such as conventional ultrasonography (US), computed tomography, and magnetic resonance imaging. Although these methods are reliable for the noninvasive detection of moderate to severe fatty changes in the liver, they are not reliable for detecting nonalcoholic steatohepatitis (NASH) and fibrosis. New imaging technologies, such as US-based transient elastography, acoustic radiation force impulse and magnetic resonance-based elastography, can reportedly be used to determine the severity of liver fibrosis associated with NASH. In this context, the field of nuclear medicine through liver scintigraphy has recently been proposed, and is being explored for use in the diagnosis of NASH. More importantly, nuclear medicine may contribute to the distinction between simple steatosis and NASH. For example, the enhanced release of cytokines and the decrease in the phagocytic activity of Kupffer cells play important roles in the pathogenesis of NASH. Removal of technetium-99m colloid from circulation by Kupffer cell phagocytosis therefore provides a valuable imaging technique. Thus, nuclear medicine is poised to provide useful tools for the evaluation of patients with NAFLD. However, the evidence is still scarce, and more studies with larger samples are needed to identify their role before they are used in clinical practice.

Fibroscan for diagnosis and treatment of chronic liver disease

Liver biopsy is still the golden standard in the diagnosis of chronic liver diseases, but it is invasive, which limits its application. Therefore, the search for a reliable noninvasive diagnostic method has attracted more and more attention. Since Fibroscan (FS) was launched in 2003, scholars have paid more attention to this modality, because it is non-invasive, painless, rapid and objective. In this paper, we will review the value of FS in the diagnosis and treatment of chronic liver disease.

Patient preference and willingness to pay for transient elastography versus liver biopsy: A perspective from British Columbia

BACKGROUND

The cost of liver biopsy (LB) is publicly funded in British Columbia, while the cost of transient elastography (FibroScan [FS], Echosens, France) is not. Consequently, there is regional variation regarding FS access and monitoring of liver disease progression.

OBJECTIVE

To evaluate patient preference for FS versus LB and to assess the willingness to self-pay for FS.

METHODS

Questionnaires were distributed in clinic and via mail to LB-experienced and LB-naive patients who underwent FS at Vancouver General Hospital, Vancouver, British Columbia.

RESULTS

The overall response rate was 76%. Of the 422 respondents, 205 were LB-experienced. The mean age was 53.5 years, 50.2% were male, 54.7% were Caucasian, 38.2% had hepatitis C and 26.3% had an annual household income >$75,000. Overall, 95.4% of patients preferred FS to LB. FS was associated with greater comfort than LB, with the majority reporting no discomfort during FS (84.1% versus 7.8% for LB), no discomfort after (96.2% versus 14.6% LB) and no feelings of anxiety after FS explanation (78.2% versus 12.7% LB). FS was also associated with greater speed, with the majority reporting short test duration (97.2% versus 48.3% LB) and short wait for the test result (95.5% versus 30.2% LB). Most (75.3%) respondents were willing to self-pay for FS, with 26.3% willing to pay $25 to $49. Patients with unknown liver disease preferred LB (OR [FS preference] 0.20 [95% CI 0.07 to 0.53]).

CONCLUSIONS

FS was the preferred method of assessing liver fibrosis among patients, with the majority willing to self-pay. To ensure consistency in access, provincial funding for FS is needed. However, LB remains the procedure of choice for individuals with an unknown diagnosis.

Points to be considered when applying FibroScan S probe in children with biliary atresia

OBJECTIVES

With the introduction of smaller probes (S1, S2), the use of transient elastography has been expanded to children. Accordingly, we aimed to address points of consideration in probe choice and interpretation of measured liver stiffness by applying and comparing FibroScan S and M probes in biliary atresia.

METHODS

Using S1, S2, and M probes, 3 liver stiffness measurements, success rates, and interquartile ranges were obtained from 100 patients. Patients were assigned to 2 groups according to thoracic perimeter (≤ 45 cm vs > 45 cm). In both groups, obtained values were compared and the relation between liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index was analyzed.

RESULTS

In the small-thorax group, the success rate was highest with the S1 probe and the intraclass correlation coefficient (ICC) was highest for S1 versus S2 (0.98), compared with that for S1 versus M (0.69) and S2 versus M (0.77). In the large-thorax group, ICC was the highest for S2 versus M (0.88), compared with that for S1 versus S2 (0.69) and S1 versus M (0.51). In the small-thorax group, correlations between aspartate aminotransferase-to-platelet ratio index and liver stiffness measurement were stronger for S1 (0.65) and S2 (0.64) than for M (0.49). In the large-thorax group, all probes showed good correlation, S1 (0.68), S2 (0.62), and M (0.62).

CONCLUSIONS

We recommend that the S1 probe is more appropriate for use in small children, especially those with a thorax perimeter of < 45 cm. If no S probe is available, the M probe may be acceptable in children whose thorax perimeter is > 45 cm.

Usefulness of transient elastography by FibroScan for the evaluation of liver fibrosis

INTRODUCTION

Liver stiffness measurement (LSM) is used for the assessment of liver fibrosis. However, there is limited data in Indian patients.

AIMS AND OBJECTIVE

The aim of this study was to find the correlation of LSM, aspartate transaminase to platelet ratio index (APRI) with fibrosis as assessed by liver biopsy (LB), and predictors of discordance between LB and LSM.

METHODS

One hundred and eighty-five consecutive patients who underwent liver biopsy and transient elastography (TE) were enrolled. Fibrosis was graded by two independent pathologists using the METAVIR classification. Area under receiver operating curves (AUROC) was used to evaluate the accuracy of transient elastography and APRI in diagnosing significant fibrosis (F>2) and cirrhosis (F4).

RESULTS

Predominant etiologies were hepatitis B (46 %) and hepatitis C (26 %). LSM was unsuccessful in ten patients (5 %) because of small intercostal space (n = 3) and obesity (n = 7). Fibrosis is significantly correlated with LSM (r = 0.901, p = 0.001) and APRI (r = 0.736, p = 0.001). There was a significant difference in median LSM value in patients with no fibrosis (F0) in comparison to patients having mild fibrosis [mild portal fibrosis (F1) + fibrosis with few septa (F2)] (4.5 vs. 7.5 kPa, p = 0.001) and advanced fibrosis [bridging fibrosis that is spreading and connecting to other areas that contain fibrosis (F3) + cirrhosis or advanced scarring of the liver (F4)] (4.5 vs. 19.4 kPa, p = 0.001). Similarly, there was a significant difference in mean APRI value in patients with F0 in comparison to patients having mild fibrosis (F1 + F2) (0.55 ± 0.31 vs. 1.09 ± 0.81, p = 0.001) and advanced fibrosis (F3 + F4) (2.3 ± 1.3, p = 0.001). AUROC for diagnosis of significant fibrosis was 0.98 (95 % confidence interval (CI) 0.963-0.999) for TE and 0.865 (95 % CI 0.810-0.920) for APRI. Optimal TE value was 10.0 kPa for diagnosis of significant fibrosis and 14.7 kPa for cirrhosis with specificity and sensitivity of 89 %, 98 % and 96 %, and 97 %, respectively. On multivariate analysis, total bilirubin and histological activity index (HAI) were identified as an independent predictor of TE inaccuracy.

CONCLUSION

LSM is a reliable predictor of hepatic fibrosis in Indian patients. LSM is superior to APRI for noninvasive diagnosis of hepatic fibrosis and cirrhosis, and high bilirubin (10.5 mg/dL) and Ishak HAI grade (>11) were independent predictors of discordance between LB and LSM.

The frequency and determinants of liver stiffness measurement failure: a retrospective study of "real-life" 38,464 examinations

Objective

To investigate the frequency and determinants of liver stiffness measurement (LSM) failure by means of FibroScan in “real-life” Chinese patients.

Methods

A total of 38,464 “real-life” Chinese patients in 302 military hospital of China through the whole year of 2013, including asymptomatic carrier, chronic hepatitis B, chronic hepatitis C, liver cirrhosis (LC), alcoholic liver disease, autoimmune liver disease, hepatocellular carcinoma (HCC) and other, were enrolled, their clinical and biological parameters were retrospectively investigated. Liver fibrosis was evaluated by FibroScan detection. S probe (for children with height less than 1.20 m) and M probe (for adults) were used. LSM failure defined as zero valid shots (unsuccessful LSM), or the ratio of the interquartile range to the median of 10 measurements (IQR/M) greater than 0.30 plus median LSM greater or equal to 7.1 kPa (unreliable LSM).

Results

LSM failure occurred in 3.34% of all examinations (1286 patients out of 38,464), among them, there were 958 cases (2.49%) with unsuccessful LSM, and 328 patients (0.85%) with unreliable LSM. Statistical analyses showed that LSM failure was independently associated with body mass index (BMI) greater than 30 kg/m², female sex, age greater than 50 years, intercostal spaces (IS) less than 9 mm, decompensated liver cirrhosis and HCC patients. There were no significant differences among other diseases. By changing another skilled operator, success was achieved on 301 cases out of 1286, which reduced the failure rate to 2.56%, the decrease was significant (P<0.0001).

Conclusions

The principal reasons of LSM failure are ascites, obesity and narrow of IS. The failure rates of HCC, decompensated LC, elder or female patients are higher. These results emphasize the need for adequate operator training, technological improvements and optimal criteria for specific patient subpopulations.

Magnetic resonance elastography of liver

Magnetic resonance elastography (MRE) assesses tissue stiffness in vivo by imaging propagating shear waves through the tissues and processing the wave information. MRE is a robust technology with excellent technical success; is applicable in almost all patients and body habitus; and has excellent reproducibility, repeatability, and interobserver agreement for assessing liver stiffness. It is currently the most accurate noninvasive technique for detection and staging of liver fibrosis and has the potential to replace liver biopsy. This article describes the principles and technique of MRE, current clinical applications, and emerging clinical indications.

Clinical Application of Transient Elastography in the Diagnosis of Liver Fibrosis: an Expert Panel Review and Opinion

Liver fibrosis evaluation is pivotal for treatment decisions and prognosis assessment in patients with chronic liver disease. Liver transient elastography (TE) is a newly developed non-invasive technique for diagnosis of liver fibrosis. It can assess the state of liver fibrosis by liver stiffness measurements, and offers better performance for the diagnosis of liver cirrhosis than serum biological markers. It has now been approved for clinical use in China. The aim of this review is to provide a guide for clinicians to apply this technique appropriately. The recommendations are made under the auspices of China Foundation for Hepatitis Prevention and Control, and have been prepared by a panel experts, who have reviewed and summarized the clinical studies on TE in order to develop these recommendations.

Coincidental metabolic syndrome increases the risk of liver fibrosis progression in patients with chronic hepatitis B--a prospective cohort study with paired transient elastography examinations

BACKGROUND

Metabolic syndrome is a known risk factor of cirrhosis in chronic hepatitis B (CHB).

AIM

To investigate the effects of coincidental metabolic syndrome on liver fibrosis progression in treatment-naïve CHB patients.

METHODS

A total of 1466 CHB patients underwent liver stiffness measurement (LSM) by transient elastography in 2006-2008; 663 patients remained treatment-naïve and had second LSM in 2010-2012. Liver fibrosis progression was defined as an increase in LSM ≥30% at the second assessment. The impact of coincidental metabolic syndrome and its factors on liver fibrosis progression were evaluated after adjustment for viral load and hepatitis activity.

RESULTS

At baseline, the mean age was 43 ± 12 years, 55% were males, serum alanine aminotransferase (ALT) was 44 ± 40 IU/L, HBV DNA was 4.0 ± 2.0 log IU/mL and LSM was 6.3 ± 3.6 kPa. Metabolic syndrome was diagnosed in 80 (12%) and 142 (21%) patients at baseline and follow-up visit, respectively; 84 (13%) and 22 (3%) patients had coincidental and resolved metabolic syndrome respectively. After an interval of 44 ± 7 months, 107 (16%) patients developed liver fibrosis progression. Coincidental metabolic syndrome [adjusted odds ratio (aOR) 2.0, 95% confidence interval (CI) 1.1-3.5, P = 0.015], central obesity (aOR 2.0, 95% CI 1.0-4.1, P = 0.05) and low level of high-density lipoprotein cholesterol (aOR 1.9, 95% CI 1.0-3.7, P = 0.04) were associated with liver fibrosis progression independent of change in viral load and ALT level. The effects of coincidental metabolic syndrome were most apparent in the immune-tolerant phase.

CONCLUSION

Coincidental metabolic syndrome increases the risk of liver fibrosis progression in patients with chronic hepatitis B infection, independent of viral load and hepatitis activity.

Systematic review with meta-analysis: non-invasive assessment of non-alcoholic fatty liver disease--the role of transient elastography and plasma cytokeratin-18 fragments

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) affects 15-40% of the general population. Some patients have non-alcoholic steatohepatitis (NASH) and progressive fibrosis, and would be candidates for monitoring and treatment.

AIM

To review current literature on the use of non-invasive tests to assess the severity of NAFLD.

METHODS

Systematic literature searching identified studies evaluating non-invasive tests of NASH and fibrosis using liver biopsy as the reference standard. Meta-analysis was performed for areas with adequate number of publications.

RESULTS

Serum tests and physical measurements like transient elastography (TE) have high negative predictive value (NPV) in excluding advanced fibrosis in NAFLD patients. The NAFLD fibrosis score comprises of six routine clinical parameters and has been endorsed by current American guidelines as a screening test to exclude low-risk individuals. The pooled sensitivities and specificities for TE to diagnose F ≥ 2, F ≥ 3 and F4 disease were 79% and 75%, 85% and 85%, and 92% and 92% respectively. Liver stiffness measurement often fails in obese patients, but the success rate can be improved with the use of the XL probe. A number of biomarkers have been developed for the diagnosis of NASH, but few were independently validated. Serum/plasma cytokeratin-18 fragments have been most extensively evaluated and have a pooled sensitivity of 66% and specificity of 82% in diagnosing NASH.

CONCLUSIONS

Current non-invasive tests are accurate in excluding advanced fibrosis in NAFLD patients, and may be used for initial assessment. Further development and evaluation of NASH biomarkers are needed.

The Emerging Role of Elastography in Cancer

Real-time elastography is an emerging sonographic imaging technique that provides a noninvasive method of evaluating biomechanical properties of a lesion: specifically, the elasticity, or stiffness, of the cellular composition relative to surrounding tissue. Clinical studies have demonstrated the diagnostic capability of elastography to detect specific cancers with accuracy that may substantially affect patient care and improve outcome. This literature review examines the basics of elastography, the advantages and limitations of this technique, and the results of research centered on its role in cancer detection and evaluation of tissue response to cancer therapies.

Noninvasive evaluation of NAFLD

A common clinical concern in patients with NAFLD is whether they have NASH or simple steatosis and, more importantly, what the stage of fibrosis is and whether the level of fibrosis has increased over time. Such concern is based on the fact that patients with NAFLD with advanced fibrosis are at greatest risk of developing complications of end-stage liver disease. Although it lacks sensitivity, ultrasonography is an accepted tool for steatosis screening. The controlled attenuation parameter or CAP seems a promising screening technique, but requires further validation. Cytokeratin-18 has been extensively validated, but it is an imperfect serum marker of NASH. Ultrasonography-based transient elastography can exclude advanced fibrosis and cirrhosis, but its main limitation is its reduced applicability in patients with NAFLD, which is not completely solved by use of the XL probe. Of the noninvasive serum markers, the NAFLD fibrosis score is the most validated and has appropriate accuracy in distinguishing patients with and without advanced fibrosis. Although noninvasive methods require further validation, they could be useful for selecting those patients with NAFLD who require a liver biopsy. This Review discusses the advantages and limitations of noninvasive methods for the management of adults with NAFLD, including diagnosis and quantification of steatosis, diagnosis of NASH and staging of hepatic fibrosis.

Correlation of MR elastography with morphometric quantification of liver fibrosis (Fibro-C-Index) in chronic hepatitis B

PURPOSE

We evaluated the correlation of MR Elastography (MRE) with morphometric assessment of liver fibrosis in chronic hepatitis B (CHB).

METHODS

Thirty-two patients with CHB underwent both MRE and a liver biopsy within a 6-month interval. MRE was performed using standard MRE sequence on a 1.5 Tesla clinical scanner. The liver stiffness (LS) was measured on automatically generated stiffness maps. Morphometric quantification of fibrosis of liver biopsies was performed using a semi-automated image analysis program and expressed as percentage area (Fibro-C-Index). Correlations between MRE, Fibro-C-Index, and histologic fibrosis stages were evaluated. Receiver operating curve (ROC) analysis of MRE and Fibro-C-index for differentiating fibrosis (≥F1), significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) was performed.

RESULTS

MRE showed excellent correlation with both Fibro-C-Index (r = 0.78, 95% confidence interval [CI], 0.59-0.88, P < 0.001) and histologic staging (rho = 0.87, 95% CI, 0.72-0.94, P < 0.0001). Significant differences in MRE (P = 0.0001) and Fibro-C-Index (P = 0.003) among different stages of liver fibrosis was found. MRE and Fibro-C-Index had similar accuracies for differentiating fibrosis stages: ≥F1 (0.87 versus 0.81, P = 0.6), ≥F2 (0.95 versus 0.94, P = 0.78), ≥F3 (0.98 versus 0.96, P = 0.76), and F4 (1.00 versus 0.92, P = 0.10).

CONCLUSION

MRE is an excellent noninvasive indicator of liver fibrosis burden in CHB.

Direct comparison of the FibroScan XL and M probes for assessment of liver fibrosis in obese and nonobese patients

BACKGROUND

A novel Fibroscan XL probe has recently been introduced and validated for obese patients, and has a diagnostic accuracy comparable with that of the standard M probe. The aim of this study was to analyze and understand the differences between these two probes in nonobese patients, to identify underlying causes for these differences, and to develop a practical algorithm to translate results for the XL probe to those for the M probe.

METHODS AND RESULTS

Both probes were directly compared first in copolymer phantoms of varying stiffness (4.8, 11, and 40 kPa) and then in 371 obese and nonobese patients (body mass index, range 17.2-72.4) from German (n = 129) and Canadian (n = 242) centers. Liver stiffness values for both probes correlated better in phantoms than in patients (r = 0.98 versus 0.82, P < 0.001). Significantly more patients could be measured successfully using the XL probe than the M probe (98.4% versus 85.2%, respectively, P < 0.001) while the M probe produced a smaller interquartile range (21% versus 32%). Failure of the M probe to measure liver stiffness was not only observed in patients with a high body mass index and long skin-liver capsule distance but also in some nonobese patients (n = 10) due to quenching of the signal from subcutaneous fat tissue. In contrast with the phantoms, the XL probe consistently produced approximately 20% lower liver stiffness values in humans compared with the M probe. A long skin-liver capsule distance and a high degree of steatosis were responsible for this discordance. Adjustment of cutoff values for the XL probe (<5.5, 5.5-7, 7-10, and >10 kPa for F0, F1-2, F3, and F4 fibrosis, respectively) significantly improved agreement between the two probes from r = 0.655 to 0.679.

CONCLUSION

Liver stiffness can be measured in significantly more obese and nonobese patients using the XL probe than the M probe. However, the XL probe is less accurate and adjusted cutoff values are required.

Direct comparison of the FibroScan XL and M probes for assessment of liver fibrosis in obese and nonobese patients

Background

A novel Fibroscan XL probe has recently been introduced and validated for obese patients, and has a diagnostic accuracy comparable with that of the standard M probe. The aim of this study was to analyze and understand the differences between these two probes in nonobese patients, to identify underlying causes for these differences, and to develop a practical algorithm to translate results for the XL probe to those for the M probe.

Methods and results

Both probes were directly compared first in copolymer phantoms of varying stiffness (4.8, 11, and 40 kPa) and then in 371 obese and nonobese patients (body mass index, range 17.2–72.4) from German (n = 129) and Canadian (n = 242) centers. Liver stiffness values for both probes correlated better in phantoms than in patients (r = 0.98 versus 0.82, P < 0.001). Significantly more patients could be measured successfully using the XL probe than the M probe (98.4% versus 85.2%, respectively, P < 0.001) while the M probe produced a smaller interquartile range (21% versus 32%). Failure of the M probe to measure liver stiffness was not only observed in patients with a high body mass index and long skin-liver capsule distance but also in some nonobese patients (n = 10) due to quenching of the signal from subcutaneous fat tissue. In contrast with the phantoms, the XL probe consistently produced approximately 20% lower liver stiffness values in humans compared with the M probe. A long skin-liver capsule distance and a high degree of steatosis were responsible for this discordance. Adjustment of cutoff values for the XL probe (<5.5, 5.5–7, 7–10, and >10 kPa for F0, F1–2, F3, and F4 fibrosis, respectively) significantly improved agreement between the two probes from r = 0.655 to 0.679.

Conclusion

Liver stiffness can be measured in significantly more obese and nonobese patients using the XL probe than the M probe. However, the XL probe is less accurate and adjusted cutoff values are required.

Liver stiffness measurement by transient elastography as a predictor on posthepatectomy outcomes

BACKGROUND

Liver fibrosis and cirrhosis are well-known risk factors for morbidity after hepatectomy. Liver stiffness measurement (LSM) using transient elastography is a new method for detection of hepatic fibrosis and cirrhosis with high accuracy. Whether LSM can predict posthepatectomy outcomes has not been studied.

METHODS

This was a prospective cohort study in which consecutive patients underwent hepatectomy for various indications from February 2010 to July 2011. All patients received detailed preoperative assessments including LSM and indocyanine green (ICG) clearance test. The primary outcome was major postoperative complication.

RESULTS

One hundred five patients with a mean age of 59 years were included; 75 (71.4%) had chronic viral hepatitis and 76 (72.4%) had hepatocellular carcinoma. Thirty-four patients (32.4%) received major hepatectomy. The median ICG retention rate at 15 minutes was 4.2 (0.1%-32%) and the median LSM was 9.4 (3.3-75 kPa). For posthepatectomy outcomes, only LSM but not ICG showed significant correlation with major postoperative complications on receiver operating characteristic curves, with area under the curve of 0.79 (P < 0.001). Using the calculated cutoff at 12.0 kPa, LSM had sensitivity of 85.7% and specificity of 71.8% in the prediction of major postoperative complications. It was also an independent prognostic factor for major postoperative complications by multivariate analysis. The operative blood loss and transfusion rate were also significantly higher in patients with LSM >12.0 kPa.

CONCLUSIONS

High LSM (>12.0 kPa) predicted worse posthepatectomy outcomes. Preoperative LSM was better than ICG test in the prediction of major postoperative complications. It was a useful preoperative investigation for risk stratification before hepatectomy.

Transient elastography: Kill two birds with one stone?

Assessment of liver fibrosis and steatosis is crucial in chronic liver diseases in order to determine the prognosis, the need of treatment, as well as monitor disease progression and response to treatment. Liver biopsy is limited by its invasiveness and patient acceptability. Transient elastography (TE, Fibroscan^®) is a non-invasive tool with satisfactory accuracy and reproducibility to estimate liver fibrosis and steatosis. TE has been well validated in major liver diseases including chronic hepatitis B and C, non-alcoholic fatty liver disease, alcoholic liver disease, primary biliary cirrhosis, and primary sclerosing cholangitis. As alanine aminotransferase (ALT) is one of the major confounding factors of liver stiffness in chronic hepatitis B, an ALT-based algorithm has been developed and higher liver stiffness measurements (LSM) cutoff values for different stages of liver fibrosis should be used in patients with elevated ALT levels up to 5 times of the upper limit of normal. Otherwise falsely-high LSM results up to cirrhotic range may occur during ALT flare. TE is also useful in predicting patient prognosis such as development of hepatocellular carcinoma (HCC), portal hypertension, post-operative complications in HCC patients, and also survival. Unfortunately, failed acquisition of TE is common in obese patients. Furthermore, obese patients may have higher LSM results even in the same stage of liver fibrosis. The new XL probe, a larger probe with lower ultrasound frequency and deeper penetration, increases the success rate of TE in obese patients. The median LSM value with XL probe was found to be lower than that by the conventional M probe, hence cutoff values approximately 1.2 to 1.3 kPa lower than those of M probe should be adopted. Recent studies revealed a novel ultrasonic controlled attenuation parameter (CAP) of the machine is a useful parameter to detect even low-grade steatosis noninvasively. CAP may also be used to quantify liver steatosis by applying different cutoff values. As both LSM and CAP results are instantly available at same measurement, this makes TE a very convenient tool to assess any patients who are suspected or confirmed to suffer from chronic liver diseases.

NAFLD in Asia--as common and important as in the West

NAFLD--regarded as a consequence of the modern sedentary, food-abundant lifestyle prevalent in the West--was recorded in Japan nearly 50 years ago and its changing epidemiology during the past three decades is well-documented. NAFLD, and its pathologically more severe form NASH, occur in genetically susceptible people who are over-nourished. Asian people are particularly susceptible, partly owing to body composition differences in fat and muscle. Community prevalence ranges between 20% (China), 27% (Hong Kong), and 15-45% (South Asia, South-East Asia, Korea, Japan and Taiwan). This Review presents emerging data on genetic polymorphisms that predispose Asian people to NAFLD, NASH and cirrhosis, and discusses the clinical and pathological outcomes of these disorders. NAFLD is unlikely to be less severe in Asians than in other populations, but the associated obesity and diabetes pandemics have occurred more recently in Asia than in Europe and the USA, and occur with reduced degrees of adiposity. Cases of cryptogenic cirrhosis and hepatocellular carcinoma have also been attributed to NAFLD. Public health efforts to curb over-nutrition and insulin resistance are needed to prevent and/or reverse NAFLD, as well as its adverse health outcomes of type 2 diabetes, cardiovascular events, cirrhosis and liver cancer.

Factors influencing reliability of liver stiffness measurements using transient elastography (M-probe)-monocentric experience

AIM

To retrospectively assess the feasibility of transient elastography (TE) and the factors associated with failed and unreliable liver stiffness measurements (LSMs), in patients with chronic liver diseases.

MATERIAL AND METHODS

Our retrospective study included 8218 consecutive adult patients with suspected chronic liver diseases. In each patient, LSMs were performed with a FibroScan(®) device (Echosens, France), with the M probe. Failure of TE measurements was defined if no valid measurement was obtained after at least 10 shots and unreliable if fewer than 10 valid shots were obtained, success rate (SR) <60% and/or interquartile range interval/median value (IQR/Med) ≥30%.

RESULTS

From the 8218 patients, failed and unreliable LSMs were observed in 29.2% of cases. In univariant analysis, the following risk factors were associated with failed and unreliable measurements: age over 50 years (OR 2.04; 95%CI 1.84-2.26), female gender (OR 1.32; 95%CI 1.20-1.45), BMI>27.7kg/m(2) (OR 2.89, 95%CI 2.62-3.19), weight>77kg (OR 2.17; 95%CI 1.97-2.40) and height<162cm (OR 1.26; 95%CI 1.14-1.40). In multivariate analysis all the factors mentioned above were independently associated with the risk of failed and unreliable measurements. If all the negative predictive factors were present (woman, older than 50 years, with BMI>27.7kg/m(2), heavier than 77kg and shorter than 162cm), the rate of failed and unreliable measurements was 58.5%. In obese patients (BMI≥30kg/m(2)), the rate of failed and unreliable measurements was 49.5%.

CONCLUSION

Failed and unreliable LSMs were observed in 29.1% of patients. Female gender, older age, higher BMI, higher weight and smaller height were significantly associated with failed and unreliable LSMs.

Update of liver fibrosis and steatosis with transient elastography (Fibroscan)

Background: Assessment of liver fibrosis and steatosis is now almost indispensable in most of the chronic liver diseases in order to determine prognosis and need for treatment, and to monitor disease progression and response to treatment. Liver biopsy is limited by its invasiveness and patient acceptability. Transient elastography (TE; Fibroscan) is a non-invasive tool with satisfactory accuracy and reproducibility to estimate liver fibrosis.

Aims & Methods: To review the existing evidence concerning the clinical applications of TE in major liver diseases, including chronic hepatitis B and -C, non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, primary biliary cirrhosis and primary sclerosing cholangitis.

Results: As alanine aminotransferase (ALT) is one of the major confounding factors of liver stiffness in chronic hepatitis B, an ALT-based algorithm has been developed and higher liver stiffness measurements (LSM) cut-off values for different stages of liver fibrosis should be used in patients with elevated ALT levels up to five times the upper limit of normal. Furthermore, falsely-high LSM results up to the cirrhotic range may occur during ALT flare. TE is also useful predicting patient prognosis in the development of hepatocellular carcinoma (HCC), portal hypertension, postoperative complications in HCC patients and survival. Unfortunately, failed acquisition of TE is common in obese patients. Furthermore, obese patients may have higher LSM results, even in the same stage of liver fibrosis. To better evaluate NAFLD a new XL probe, with a larger probe with lower ultrasound frequency and deeper penetration, increases the success rate of TE in obese patients. The median LSM value with the XL probe was found to be lower than that by the conventional M probe, hence cut-off values were approximately 1.2 to 1.3 kilopascals lower than those of the M probe, suggesting its adoption. Studies reveal that a novel ultrasonic controlled attenuation parameter is potentially useful to detect and quantify hepatic steatosis non-invasively.

Conclusion: TE is a non-invasive, accurate and reproducible test of liver fibrosis and possibly hepatic steatosis and has been validated in a wide spectrum of liver diseases. TE is also useful to predict patient outcomes.

Association between anthropometric parameters and measurements of liver stiffness by transient elastography

BACKGROUND & AIMS

We investigated the association between anthropometric parameters and results of liver stiffness measurements (LSMs) by transient elastography in healthy subjects and patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

We analyzed anthropometric and LSM data from 658 healthy subjects (37% male; mean age, 47 ± 11 years; body mass index [BMI], 21.8 ± 3.0 kg/m(2); LSM, 4.4 ± 1.6 kPa) and 247 patients with biopsy-proven NAFLD (50% male; mean age, 48 ± 11 years; BMI, 28.6 ± 6.5 kg/m(2); LSM, 9.6 ± 8.7 kPa). Healthy subjects were defined as individuals without viral hepatitis, alcoholic liver disease, or NAFLD. We investigated associations between anthropometric parameters, including BMI and waist circumference, and LSM.

RESULTS

LSMs were slightly higher among healthy subjects with BMIs ≤ 18.5 kg/m(2) (n = 84, 4.8 ± 1.5 kPa) and BMIs of 25-29.9 kg/m(2) (n = 76, 5.3 ± 2.2 kPa) than those with BMIs of 18.5-24.9 kg/m(2) (n = 492, 4.5 ± 1.9 kPa; P = .16 by analysis of variance). Among patients with NAFLD of Brunt fibrosis stage 0 or 1, LSMs were lowest among those with BMIs of 18.5-24.9 kg/m(2) (stage 0: n = 34, 5.5 ± 2.2 kPa; stage 1: n = 18, 7.2 ± 3.8 kPa). LSMs were higher among those with BMIs of 25-29.9 kg/m(2) (stage 0: n = 41, 6.1 ± 1.3 kPa; stage 1: n = 26, 7.9 ± 3.5 kPa) and highest for those with BMIs ≥30 kg/m(2) (stage 0: n = 13, 8.5 ± 2.2 kPa; stage 1: n = 22, 11.7 ± 5.2 kPa) (P < .001 and P = .002, respectively, by analysis of variance). High BMI was independently associated with high LSM, in addition to fibrosis stage, among patients with NAFLD. Patients with different waist circumferences had comparable LSMs.

CONCLUSIONS

BMI ≥30 kg/m(2) is associated with higher LSMs in patients with NAFLD, after adjusting for fibrosis stage.

Serum GP73, a marker for evaluating progression in patients with chronic HBV infections

This study was designed to investigate the role of serum GP73 for diagnosing significant fibrosis in patients with chronic hepatitis B virus (HBV) infections. Two populations were enrollment. All subjects were patients with chronic HBV infections. First population included 761 patients, who received liver stiffness measurement; the second population included 633 patients, who undertaken liver biopsy, in which 472 patients with nearly normal ALT. All patients received serum GP73 test. The effect of GP73 recombinant protein to HepG2 cells and LX2 cells were observed in vitro. Results showed that serum GP73 concentration is correlated with liver stiffness (r = 0.601). The area under ROC curve is 0.76. The sensitivity and specificity of GP73 for significant fibrosis (≥F2) diagnosis were 62.81%, 80.05% respectively (cut off: 76.6 ng/ml). Serum GP73 concentration was significantly correlated with the grading of fibrosis (r = 0.32, and 0.35, in 633 and 472 patients, respectively.) GP73 had a striking performance for diagnosing S2 in patients with chronic HBV infections. In 472 patients with nearly normal ALT, the sensitivity and specificity of GP73 for S2 diagnosis were 62.5% and 80.0% respectively, where the cut-off was set at 82 ng/ml. GP73 recombinant protein may prompt LX2 cells proliferation at the concentration 10–100 ng/ml. The present results indicated that GP73 may be a marker for diagnosing significant fibrosis in patients with chronic HBV infections, and may be a new contributor to fibrogensis.

Nonalcoholic fatty liver disease in Asia: a story of growth

Ten years ago, few if any researchers in Asia showed interest in nonalcoholic fatty liver disease (NAFLD). Today, NAFLD is increasingly recognized as a major chronic liver disease not only in Western countries but also in Asia. Its importance is exemplified by its high prevalence, disease progression, and association with major medical disorders. In Asia, 15-30% of the general adult population suffers from NAFLD. In patients with diabetes and metabolic syndrome, the reported prevalence is typically over 50%. Patients with the active form of NAFLD, namely steatohepatitis (NASH), may have fibrosis progression and eventually develop cirrhosis. Patients with NASH-related cirrhosis have similar mortality to those with other causes of cirrhosis, and they have a high risk of developing hepatocellular carcinoma up to 2-3% per year. In addition, NAFLD patients have a high prevalence of cardiovascular disease and colorectal neoplasm. One major challenge for practicing clinicians is how to identify patients with significant liver disease among many who are found to have NAFLD. While liver biopsy is traditionally considered the gold standard for disease staging, it is invasive and unpleasant, and is an impractical tool for a disease that affects a quarter of the general population. To this end, new developments in transient elastography and biomarkers such as cytokeratin-18 fragments can help exclude significant liver fibrosis and NASH, respectively. This article summarizes a young researcher's journey through this exciting area of research and what he has learned from amazing people all around the world.

Liver stiffness measurement using XL probe in patients with nonalcoholic fatty liver disease

OBJECTIVES

Liver stiffness measurement (LSM) by transient elastography is a noninvasive test of liver fibrosis, but cannot be performed in a significant proportion of obese patients. The aim of this study was to evaluate the performance of the new XL probe in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

Liver biopsy and paired LSM by both the original M probe and XL probe were performed on 193 consecutive NAFLD patients in France and Hong Kong.

RESULTS

Compared with M probe, XL probe was more likely to achieve 10 valid measurements (95% vs. 81%; P<0.001) and a success rate of over 60% (90% vs. 74%; P<0.001). The areas under receiver operating characteristics curves of XL probe for F2, F3, and F4 disease were 0.80, 0.85, and 0.91, respectively. XL probe tended to generate lower LSM than M probe in the same patient. At a cutoff of 7.2 kPa, the sensitivity, specificity, positive, and negative predictive values for F3 or greater disease were 78%, 78%, 60%, and 89%, respectively. Discordance of at least two stages between XL probe and histology was observed in 16 (9%) patients. Body mass index (BMI) over 35 kg/m(2) was independently associated with discordance (adjusted odds ratio 9.09; 95% confidence interval 1.10-75.43). Reliable measurements by XL probe were obtained in 75% of the overall population and 65% of patients with BMI over 30 kg/m(2).

CONCLUSIONS

LSM by XL probe can be performed successfully in most NAFLD patients, but obesity is associated with less accurate and reliable measurements.

Interobserver discrepancy in liver fibrosis using transient elastography

Transient elastography is a useful method to assess liver fibrosis, but uncertainties still exist regarding reliability and reproducibility of the technique. We aimed to improve knowledge on interobserver variability with the procedure and tried to find factors associated with such variability. This was a cross-sectional study to compare the results of transient elastography performed by two different operators, one test made just after the other. We assessed both results with correlation tests and with repeated parametric or nonparametric tests, as needed. We also carried out a multivariate analysis to find factors associated with discrepancy in the results obtained by the two operators. We included a total of 333 pairs of transient elastography tests, belonging to 274 different patients. A total of 325 pairs of tests (97.6%) were valid. Results of the first and the second tests were, respectively, median (and interquartile range) of direct measurement 6.2 (4.6-10.6) and 6.0 (4.4-10.1) kPa (P = 0.012), and mean ± standard deviation of log(10) of direct measurement 0.892 ± 0.316 and 0.871 ± 0.324 (P = 0.001). In 87 pairs of tests (26.7%), a discrepancy of at least 2 kPa between both results was found, and in 15 pairs of tests (4.6%), a discrepancy of at least 10 kPa was found. Discordance of at least one stage between both measurements was noted in 74 pairs of tests (22.8%). An association was found between higher stiffness and discrepancy between both operators (P < 0.001). Although transient elastography is a very convenient test to assess liver fibrosis in clinical practice, interobserver discrepancy in results is common and represents a significant problem with the technique. Discrepant results are more common in patients with higher values of stiffness.