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

FibroScan's evolution: a critical 20-year review

FibroScan, initially designed for assessing cheese maturity, has evolved into a crucial medical tool for liver fibrosis diagnosis. This systematic review explores its development history, functionality, and pros and cons compared to traditional liver biopsy. Precision in various clinical settings is scrutinised, emphasising FibroScan's accuracy in conditions like NAFLD and viral-induced liver disease. The article also delves into its potential in paediatrics, its relevance in monitoring COVID-19-related liver complications, and its role in predicting hepatocellular carcinoma risk, Technical aspects, including transducers, imaging integration, and portability, are examined. Various methods for evaluating liver fibrosis are discussed, highlighting FibroScan's suitability for advanced stages, contrasting with the gold standard of liver biopsy for early stages. The impact of FibroScan on long-term liver conditions is emphasised, focusing on early detection, progression monitoring, reduced invasive biopsies, and hepatocellular carcinoma risk prediction. This systematic review underscores FibroScan's transformative potential in liver disease treatment and predicts ongoing research to enhance early detection, disease monitoring, and explore new clinical applications. Anticipated advances include FibroScan-guided liver biopsy, artificial intelligence data analysis, and point-of-care device development, promising a further revolution in liver disease management. The article concludes with optimistic prospects for FibroScan's future.

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

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

Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity

Background

Vibration controlled transient elastography (VCTE) and controlled attenuation parameter (CAP™) have shown reliable performance predicting fibrosis and steatosis in normal- to overweight patients but have not been validated in severe to morbid obesity. This study aimed at determining the accuracy of VCTE, CAP™ and the composite score FibroScan-AST (FAST) in patients with a body mass index (BMI) of ≥35 kg/m².

Methods

Patients scheduled for bariatric-metabolic surgery underwent preoperative VCTE/CAP™ measurement, and intraoperative liver biopsy. The feasibility and accuracy of VCTE, CAP™ and the composite score FAST were retrospectively analysed to evaluate fibrosis, steatosis and active fibrotic non-alcoholic steatohepatitis [NASH + non-alcoholic fatty liver disease (NAFLD) activity score ≥4 + fibrosis grade ≥2] using per protocol (PP) and intent to diagnose (ITD) calculation.

Results

In total, 170 patients (median BMI 44.4 kg/m²) were included in the study. Liver biopsy showed NASH, simple steatosis, and normal livers in 60.6% (n=103), 28.8% (n=49), and 10.6% (n=18), respectively. VCTE and CAP™ delivered reliable results in 90.6% (n=154/170) and 90.5% (n=134/148). The AUC (PP) of VCTE, CAP™, and FAST were 0.687 (≥F2), 0.786 (≥F3), 0.703 (≥S2), 0.738 (S3), and 0.780 (active fibrotic NASH). The AUC increased to 0.742 (≥F2), 0.842 (≥F3), 0.712 (≥S2), 0.780 (S3), and 0.836 (active fibrotic NASH) in patients below the median BMI of 44.4 kg/m².

Conclusions

VCTE, CAP™ and FAST show acceptable accuracy for the detection of fibrosis, steatosis and NASH in a real-life cohort of patients with obesity. Accuracy improves in patients with a BMI <44.4 kg/m².

Transient elastography versus liver biopsy: discordance in evaluations for fibrosis and steatosis from a pathology standpoint

Vibration-controlled transient elastography (VCTE) is a non-invasive method of evaluating liver fibrosis and steatosis. It can easily be performed in the outpatient setting and has been suggested as an alternative to liver biopsy. However, VCTE and biopsy discrepancies commonly occur. Patient characteristics, procedure performance, and liver features can impact the reliability of VCTE results. We identified 82 patients who received VCTE and biopsy within one month to assess how frequently major discrepancies occur and to determine the role of the liver biopsy in this workup. In our study, 35.4% of patients had a major fibrosis discrepancy, which was defined as advanced fibrosis or cirrhosis by VCTE and no to minimal fibrosis on biopsy. This was significantly associated with increased BMI, and liver features including steatohepatitis, inflammation, congestion, and cholestasis were important contributors to discrepancies. All patients with advanced fibrosis or cirrhosis on liver biopsy were appropriately detected by VCTE (n = 28). Detection of steatosis was less sensitive as 19% (n = 4 of 21) of patients with moderate to severe steatosis on biopsy were missed by VCTE. Liver biopsy has been traditionally performed for diagnosis, but with the emergence of non-invasive tools to evaluate for liver fibrosis and steatosis, biopsies are now additionally being performed to confirm findings from noninvasive procedures. Although VCTE is a highly sensitive tool for liver fibrosis, it is not as specific, and therefore, the liver biopsy remains the gold standard for accurate fibrosis assessment.

Fibroscan® probe selection for lean adults

Background and Aim

Fibroscan® is used to assess fibrosis and steatosis of the liver noninvasively. The company suggests to use the S+‐probe in people <18 years with a thoracic circumference (TC) between 45 and 75 cm and the M+‐probe in children with a TC >75 cm and adults with a skin–liver capsule distance <2.5 cm. For lean adults with a TC ≤75 cm, no comparative studies have been performed. Furthermore, it is unclear whether lean adults need to be fasted before assessment.

Methods

We compared liver stiffness (LS) using Fibroscan® S+‐ and M+‐probes and controlled attenuation parameter (CAP; only available for M+‐probe) in healthy volunteers with a TC ≤75 cm compared with those with a TC >75 cm in fasting state and after intake of a standardized light meal (300 kcal).

Results

We examined 50 volunteers (26 female, 24 ± 3 years). Twenty‐two participants were in the TC ≤75 cm group and 28 in TC >75 cm group. LS values with the S+‐probe were 15% higher than with the M+‐probe in both groups (median difference 0.6 kPa, P < 0.001). Both probes showed good agreement with minimal bias (Spearman correlation r = 0.754, P < 0.001; Interclass Correlation Coefficient 0.843, P < 0.001; Bland–Altman bias 0.6 ± 0.9 kPa, linear regression r² = 0.557, P < 0.001). Intake of a light meal had no relevant influence on LS (S+‐ and M+‐probes) or CAP measurements (M+‐probe) in both groups.

Conclusion

Lean adults with a TC below 75 cm can be assessed with either the S+‐probe or the M+‐probe and may take a light meal before assessment.

Assessment of hepatic fibrosis and steatosis by vibration-controlled transient elastography and controlled attenuation parameter versus non-invasive assessment scores in patients with non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) is regarded as the most common liver disease in the twenty-first century, and a condition leaving individuals at increased risk of extra-hepatic morbidity. Liver biopsy has long been regarded as the gold standard for diagnosis and prognostication of patients with NAFLD. However, due to its invasive nature and potential complications (e.g., bleeding), other methods for non-invasive laboratory and radiological assessment of hepatic steatosis and fibrosis in NAFLD have evolved and include scores such as AST/Platelet Ratio Index (APRI), Fibrosis-4 (FIB-4) score, NAFLD fibrosis score (NFS), and fatty liver index (FLI), in addition to radiological methods such as transient elastography (TE), which is a well-validated non-invasive ultrasound-based technique for assessment of hepatic fibrosis. Recently, novel development of controlled attenuation parameter (CAP) in TE allowed simultaneous assessment of hepatic steatosis. This provided a chance to assess both hepatic fibrosis and steatosis in the same setting and without any unwanted complications. This study aimed at assessing the role of TE and CAP versus other non-invasive assessment scores for liver fibrosis and steatosis in patients with NAFLD.

Results

This study included 90 patients diagnosed with NAFLD based on abdominal ultrasonography, body mass index, and serum liver enzymes. All patients were assessed with TE and non-invasive scores (APRI score, FIB-4 score, NFS, and FLI). There was a highly significant positive correlation between fibrosis and steatosis grades assessed by TE and other non-invasive respective scores. Both TE and CAP achieved acceptable sensitivity and specificity compared to other non-invasive assessment methods.

Conclusions

TE with CAP can be used as a screening method for patients suspected with NAFLD or patients without a clear indication for liver biopsy. CAP allows a non-invasive method of assessment of hepatic steatosis in patients with NAFLD.

Non-alcoholic fatty liver disease in lean individuals

Non-alcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, encompassing a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis, which can progress to cirrhosis. It has recently been recognised that NAFLD also occurs in individuals who are not obese, especially in Asian populations. In these patients, NAFLD manifests at lower overall body mass index thresholds in the presence of increased visceral adipose tissue. Currently, the principles of clinical management are similar to those in obese individuals, although, in specific regions and clinical situations, unique aetiologies of NAFLD must be treated specifically.

Liver stiffness reversibly increases during pregnancy and independently predicts preeclampsia

AIM

To study liver stiffness (LS) during pregnancy and its association with complications during pregnancy.

METHODS

In this observational, diagnostic study, 537 pregnant women were prospectively enrolled at the Department of Obstetrics and Gynecology, University hospital Heidelberg and Salem Medical Center. LS was measured using the Fibroscan device (Echosens, Paris) in all women and in 41 cases 24 h after delivery. Clinical and morphological data were recorded and abdominal ultrasound and standard laboratory tests were performed. No complications were observed in 475 women (controls) while preeclampsia and intrahepatic cholestasis of pregnancy (ICP) developed in 22 and 40 women, respectively.

RESULTS

In controls, LS increased significantly from initially 4.5 ± 1.2 kPa in the second trimester to 6.0 ± 2.3 kPa (P < 0.001) in the third trimester. In the third trimester, 41% of women had a LS higher than 6 kPa. Elevated LS in controls was significantly correlated with alkaline phosphatase, leukocytes, gestational age and an increase in body weight and body mass index (BMI). In women with pregnancy complications, LS was significantly higher as compared to controls (P < 0.0001). Moreover, in multivariate analysis, LS was an independent predictor for preeclampsia with an odds ratio of 2.05 (1.27-3.31) and a cut-off value of 7.6 kPa. In contrast, ICP could not be predicted by LS. Finally, LS rapidly decreased in all women within 24 h after delivery from 7.2 ± 3.3 kPa down to 4.9 ± 2.2 kPa (P < 0.001).

CONCLUSION

During pregnancy, LS significantly and reversibly increases in the final trimester of pregnant women without complications. In women with preeclampsia, LS is significantly elevated and an independent non-invasive predictor.

A Pragmatic Approach Identifies a High Rate of Nonalcoholic Fatty Liver Disease With Advanced Fibrosis in Diabetes Clinics and At-Risk Populations in Primary Care

Noninvasive serum biomarkers (nonalcoholic fatty liver disease fibrosis score [NFS], fibrosis 4 score [FIB‐4], or enhanced liver fibrosis [ELF] test) are recommended as first‐line tools to determine the risk of advanced fibrosis in nonalcoholic fatty liver disease. We aimed to assess the utility of a pragmatic approach to screening for clinically significant fibrosis in primary care and diabetes clinics. We recruited 252 patients from an endocrine clinic or primary care facility. Anthropometric measurements, ELF test, ultrasound, and liver stiffness measurements (LSMs) were performed. Clinically significant fibrosis was defined as LSM ≥8.2 kPa or ELF ≥9.8. A subgroup of patients underwent liver biopsy (n = 48) or had imaging diagnostic of cirrhosis (n = 14). Patients were 57.3 ± 12.3 years old with a high prevalence of metabolic syndrome (84.5%), type 2 diabetes (82.5%), and body mass index (BMI) ≥40 kg/m² (21.8%). LSM met quality criteria in 230 (91.3%) patients. NFS and FIB‐4 combined had a high negative predictive value (90.0%) for excluding LSM ≥8.2 kPa. However, 84.1% of patients had indeterminate or high NFS or FIB‐4 scores requiring further assessment. LSM ≥8.2 kPa and ELF ≥9.8 were present in 31.3% and 28.6% of patients, respectively. Following adjustment for age, BMI, sex, and presence of advanced fibrosis, older age was independently associated with ELF ≥9.8 (adjusted odds ratio, 1.14; 95% confidence interval, 1.06‐1.24), whereas increasing BMI was independently associated with LSM ≥8.2 kPa (adjusted odds ratio, 1.15; 95% confidence interval, 1.01‐1.30). Concordant LSM <8.2 kPa and ELF <9.8 and concordant LSM ≥8.2 kPa and ELF ≥9.8 had a high negative predictive value (91.7%) and positive predictive value (95.8%) for excluding and identifying clinically significant fibrosis, respectively. Conclusion: Simple scoring tools alone lack accuracy. LSM accuracy is influenced by severe obesity, whereas age impacts the ELF test. Further studies are required to confirm whether combining LSM and ELF may enhance accuracy and confidence in identifying clinically significant fibrosis. (Hepatology Communications 2018; 00:000‐000)

Virtual touch quantification (VTq) elastography for non-invasive assessment of liver disease and its complications: what the clinician needs to know

Liver stiffness measurement (LSM) is the most widely used non-invasive alternative to biopsy for assessing liver fibrosis in the UK. Virtual touch quantification (VTq, also known as acoustic radiation force impulse) is the principal available alternative to transient elastography (Fibroscan) and is delivered via software enhancements to standard ultrasound (US) machines. It has recently been endorsed by National Institute for Health and Care Excellence in terms of both accuracy and cost-effectiveness for use in viral hepatitis. However, while an increasing proportion of radiologists use VTq, familiarity among gastroenterologists and trainees with LSM techniques is variable and implementation is patchy. This review considers the background, evidence for and practical use of VTq elastography in clinical practice in the UK. Potential future developments in this rapidly evolving field are also highlighted.

Primary liver injury and delayed resolution of liver stiffness after alcohol detoxification in heavy drinkers with the PNPLA3 variant I148M

AIM

To investigate the influence of PNPLA3 genotype in heavy drinkers on serum markers and liver stiffness (LS) during alcohol withdrawal and its association with histology.

METHODS

Caucasian heavy drinkers (n = 521) with a mean alcohol consumption of 192.1 g/d (median alcohol consumption: 169.0 g/d; 95%CI: 179.0-203.3) were enrolled at the Salem Medical Center, University of Heidelberg. LS was measured by transient elastography (Fibroscan, Echosens SA, Paris, France). LS and serum markers were prospectively studied in these patients with all stages of alcoholic liver disease (steatosis, steatohepatitis, fibrosis) prior and after alcohol detoxification with a mean observation interval of 6.2 ± 3.2 d. A liver biopsy with histological analysis including the Kleiner score was obtained in 80 patients.

RESULTS

The PNPLA3 rs738409 genotype distribution for CC, CG and GG was 39.2%, 52.6% and 8.2%. GG genotype primarily correlated with histological steatohepatitis (r = 0.404, P < 0.005), ballooning (r = 0.319, P < 0.005) and less with steatosis (r = 0.264, P < 0.05). Mean LS was lowest in CC carriers (13.1 kPa) as compared to CG and GG carriers (17.6 and 17.2 kPa). Notably, LS primarily correlated with fibrosis stage (r = 0.828, P < 0.005), ballooning (r = 0.516, P < 0.005), steatohepatitis (r = 0.319, P < 0.005) but not with steatosis. After alcohol withdrawal, LS did not change in CC carriers, significantly decreased in CG-carriers from 17.6 to 12.7 kPa but to a lesser extent in GG carriers from 17.6 to 14.5 kPa. This was due to prolonged resolution of inflammation with significantly elevated aspartate transaminase levels after alcohol withdrawal in GG carriers. Non-invasive fibrosis assessment by LS in all patients showed a significantly higher F0 rate as compared to the biopsy cohort (47% vs 6%) with 3.8% more CC carriers while 3.7% less were seen in the F4 cirrhosis group. Thus, about 20% of patients with alcoholic liver cirrhosis would be attributable to PNPLA3 G variants. The OR to develop cirrhosis corrected for age, gender and body mass index was 1.295 (95%CI: 0.787-2.131) for CG + GG carriers.

CONCLUSION

In heavy drinkers, PNPLA3 GG primarily correlates with ballooning/steatohepatitis but not steatosis resulting in a delayed inflammation-associated resolution of LS. Consequently, sustained ballooning-associated LS elevation seems to be a potential risk factor for fibrosis progression in PNPLA3 GG carriers.

Shear wave elastography with a new reliability indicator

Non-invasive methods for liver stiffness assessment have been introduced over recent years. Of these, two main methods for estimating liver fibrosis using ultrasound elastography have become established in clinical practice: shear wave elastography and quasi-static or strain elastography. Shear waves are waves with a motion perpendicular (lateral) to the direction of the generating force. Shear waves travel relatively slowly (between 1 and 10 m/s). The stiffness of the liver tissue can be assessed based on shear wave velocity (the stiffness increases with the speed). The European Federation of Societies for Ultrasound in Medicine and Biology has published Guidelines and Recommendations that describe these technologies and provide recommendations for their clinical use. Most of the data available to date has been published using the Fibroscan (Echosens, France), point shear wave speed measurement using an acoustic radiation force impulse (Siemens, Germany) and 2D shear wave elastography using the Aixplorer (SuperSonic Imagine, France). More recently, also other manufacturers have introduced shear wave elastography technology into the market. A comparison of data obtained using different techniques for shear wave propagation and velocity measurement is of key interest for future studies, recommendations and guidelines. Here, we present a recently introduced shear wave elastography technology from Hitachi and discuss its reproducibility and comparability to the already established technologies.

Non-invasive diagnosis of alcoholic liver disease

Alcoholic liver disease (ALD) is the most common liver disease in the Western world. For many reasons, it is underestimated and underdiagnosed. An early diagnosis is absolutely essential since it (1) helps to identify patients at genetic risk for ALD; (2) can trigger efficient abstinence namely in non-addicted patients; and (3) initiate screening programs to prevent life-threatening complications such as bleeding from varices, spontaneous bacterial peritonitis or hepatocellular cancer. The two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis (AH). The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on a combination of laboratory, clinical and imaging findings. It is not widely conceived that conventional screening tools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca. 40% of manifest alcoholic liver cirrhosis. Non-invasive methods such as transient elastography (Fibroscan), acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of alcoholic cirrhosis. Present algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca. 95% of patients. The correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase levels. Other non-invasive methods such as controlled attenuation parameter, serum levels of M30 or M65, susceptometry or breath tests are under current evaluation to assess the degree of steatosis, apoptosis and iron overload in these patients. Liver biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH.

Non-invasive diagnosis of alcoholic liver disease

Alcoholic liver disease (ALD) is the most common liver disease in the Western world. For many reasons, it is underestimated and underdiagnosed. An early diagnosis is absolutely essential since it (1) helps to identify patients at genetic risk for ALD; (2) can trigger efficient abstinence namely in non-addicted patients; and (3) initiate screening programs to prevent life-threatening complications such as bleeding from varices, spontaneous bacterial peritonitis or hepatocellular cancer. The two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis (AH). The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on a combination of laboratory, clinical and imaging findings. It is not widely conceived that conventional screening tools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca. 40% of manifest alcoholic liver cirrhosis. Non-invasive methods such as transient elastography (Fibroscan), acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of alcoholic cirrhosis. Present algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca. 95% of patients. The correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase levels. Other non-invasive methods such as controlled attenuation parameter, serum levels of M30 or M65, susceptometry or breath tests are under current evaluation to assess the degree of steatosis, apoptosis and iron overload in these patients. Liver biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH.