EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 1: Basic principles and technology

The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 1: basic principles and terminology

Conventional diagnostic ultrasound images of the anatomy (as opposed to blood flow) reveal differences in the acoustic properties of soft tissues (mainly echogenicity but also, to some extent, attenuation), whereas ultrasound-based elasticity images are able to reveal the differences in the elastic properties of soft tissues (e.g., elasticity and viscosity). The benefit of elasticity imaging lies in the fact that many soft tissues can share similar ultrasonic echogenicities but may have different mechanical properties that can be used to clearly visualize normal anatomy and delineate pathologic lesions. Typically, all elasticity measurement and imaging methods introduce a mechanical excitation and monitor the resulting tissue response. Some of the most widely available commercial elasticity imaging methods are 'quasi-static' and use external tissue compression to generate images of the resulting tissue strain (or deformation). In addition, many manufacturers now provide shear wave imaging and measurement methods, which deliver stiffness images based upon the shear wave propagation speed. The goal of this review is to describe the fundamental physics and the associated terminology underlying these technologies. We have included a questions and answers section, an extensive appendix, and a glossary of terms in this manuscript. We have also endeavored to ensure that the terminology and descriptions, although not identical, are broadly compatible across the WFUMB and EFSUMB sets of guidelines on elastography (Bamber et al. 2013; Cosgrove et al. 2013).

EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 2: Clinical applications

The clinical part of these Guidelines and Recommendations produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology EFSUMB assesses the clinically used applications of all forms of elastography, stressing the evidence from meta-analyses and giving practical advice for their uses and interpretation. Diffuse liver disease forms the largest section, reflecting the wide experience with transient and shear wave elastography . Then follow the breast, thyroid, gastro-intestinal tract, endoscopic elastography, the prostate and the musculo-skeletal system using strain and shear wave elastography as appropriate. The document is intended to form a reference and to guide clinical users in a practical way.

EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Long Version)

We present here the first update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography, focused on the assessment of diffuse liver disease. The first part (long version) of these Guidelines and Recommendations deals with the basic principles of elastography and provides an update of how the technology has changed. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided regarding optimization of scanning technique, image display, image interpretation, reporting of data and some of the known image artefacts. The second part provides clinical information about the practical use of elastography equipment and the interpretation of results in the assessment of diffuse liver disease and analyzes the main findings based on published studies, stressing the evidence from meta-analyses. The role of elastography in different etiologies of liver disease and in several clinical scenarios is also discussed. All of the recommendations are judged with regard to their evidence-based strength according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. This updated document is intended to act as a reference and to provide a practical guide for both beginners and advanced clinical users.

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced these guidelines for the use of elastography techniques in liver disease. For each available technique, the reproducibility, results, and limitations are analyzed, and recommendations are given. Finally, recommendations based on the international literature and the findings of the WFUMB expert group are established as answers to common questions. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.

Performance of Acoustic Radiation Force Impulse imaging for the staging of liver fibrosis: a pooled meta-analysis

Acoustic Radiation Force Impulse (ARFI) imaging is a novel ultrasound-based elastography method that is integrated in a conventional ultrasound machine enabling the exact localization of measurement site. It might present an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. At present, studies with small patient population have shown promising results. A systematic review and meta-analysis of pooled patient data were performed to evaluate the overall performance of ARFI for the staging of liver fibrosis. Literature databases were searched up to 10/2010. The authors of the original publication were contacted, and the original patient data were requested. A meta-analysis was performed using a random effect meta-analytic method for diagnostic tests. In addition, available data comparing ARFI with FibroScan with the DeLong test were evaluated. Literature search yielded nine full-paper publications evaluating ARFI while using liver biopsy as reference method. Original patient data were available from eight studies including 518 patients. The mean diagnostic accuracy of ARFI expressed as areas under ROC curves (AUROC) was 0.87 for the diagnosis of significant fibrosis (F ≥ 2), 0.91 for the diagnosis of severe fibrosis (F ≥ 3), and 0.93 for the diagnosis of cirrhosis. ARFI can be performed with good diagnostic accuracy for the noninvasive staging of liver fibrosis.

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

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

Assessment of biopsy-proven liver fibrosis by two-dimensional shear wave elastography: An individual patient data-based meta-analysis

Two-dimensional shear wave elastography (2D-SWE) has proven to be efficient for the evaluation of liver fibrosis in small to moderate-sized clinical trials. We aimed at running a larger-scale meta-analysis of individual data. Centers which have worked with Aixplorer ultrasound equipment were contacted to share their data. Retrospective statistical analysis used direct and paired receiver operating characteristic and area under the receiver operating characteristic curve (AUROC) analyses, accounting for random effects. Data on both 2D-SWE and liver biopsy were available for 1,134 patients from 13 sites, as well as on successful transient elastography in 665 patients. Most patients had chronic hepatitis C (n = 379), hepatitis B (n = 400), or nonalcoholic fatty liver disease (n = 156). AUROCs of 2D-SWE in patients with hepatitis C, hepatitis B, and nonalcoholic fatty liver disease were 86.3%, 90.6%, and 85.5% for diagnosing significant fibrosis and 92.9%, 95.5%, and 91.7% for diagnosing cirrhosis, respectively. The AUROC of 2D-SWE was 0.022-0.084 (95% confidence interval) larger than the AUROC of transient elastography for diagnosing significant fibrosis (P = 0.001) and 0.003-0.034 for diagnosing cirrhosis (P = 0.022) in all patients. This difference was strongest in hepatitis B patients.

CONCLUSION

2D-SWE has good to excellent performance for the noninvasive staging of liver fibrosis in patients with hepatitis B; further prospective studies are needed for head-to-head comparison between 2D-SWE and other imaging modalities to establish disease-specific appropriate cutoff points for assessment of fibrosis stage. (Hepatology 2018;67:260-272).

Meta-analysis: ARFI elastography versus transient elastography for the evaluation of liver fibrosis

AIMS

This meta-analysis aims to compare the diagnostic performance of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in the assessment of liver fibrosis using liver biopsy (LB) as 'gold-standard'.

METHODS

PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases were searched for all studies published until 31 May 2012 that evaluated the liver stiffness by means of ARFI, TE and LB. Information abstracted from each study according to a fixed protocol included study design and methodological characteristics, patient characteristics, interventions, outcomes and missing outcome data.

RESULTS

Thirteen studies (11 full-length articles and 2 abstracts) including 1163 patients with chronic hepatopathies were included in the analysis. Inability to obtain reliable measurements was more than thrice as high for TE as that of ARFI (6.6% vs. 2.1%, P < 0.001). For detection of significant fibrosis, (F ≥ 2) the summary sensitivity (Se) was 0.74 (95% CI: 0.66-0.80) and specificity (Sp) was 0.83 (95% CI: 0.75-0.89) for ARFI, while for TE the Se was 0.78 (95% CI: 0.72-0.83) and Sp was 0.84 (95% CI: 0.75-0.90). For the diagnosis of cirrhosis, the summary Se was 0.87 (95% CI: 0.79-0.92) and Sp was 0.87 (95% CI: 0.81-0.91) for ARFI elastography, and, respectively, 0.89 (95% CI: 0.80-0.94) and 0.87 (95% CI: 0.82-0.91) for TE. The diagnostic odds ratio of ARFI and TE did not differ significantly in the detection of significant fibrosis [mean difference in rDOR = 0.27 (95% CI: 0.69-0.14)] and cirrhosis [mean difference in rDOR = 0.12 (95% CI: 0.29-0.52)].

CONCLUSION

Acoustic radiation force impulse elastography seems to be a good method for assessing liver fibrosis, and shows higher rate of reliable measurements and similar predictive value to TE for significant fibrosis and cirrhosis.

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 2: breast

The breast section of these Guidelines and Recommendations for Elastography produced under the auspices of the World Federation of Ultrasound in Medicine and Biology (WFUMB) assesses the clinically used applications of all forms of elastography used in breast imaging. The literature on various breast elastography techniques is reviewed, and recommendations are made on evidence-based results. Practical advice is given on how to perform and interpret breast elastography for optimal results, with emphasis placed on avoiding pitfalls. Artifacts are reviewed, and the clinical utility of some artifacts is discussed. Both strain and shear wave techniques have been shown to be highly accurate in characterizing breast lesions as benign or malignant. The relationship between the various techniques is discussed, and recommended interpretation based on a BI-RADS-like malignancy probability scale is provided. This document is intended to be used as a reference and to guide clinical users in a practical way.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

How to perform Contrast-Enhanced Ultrasound (CEUS)

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

The EFSUMB Guidelines and Recommendations for the Clinical Practice of Elastography in Non-Hepatic Applications: Update 2018

This manuscript describes the use of ultrasound elastography, with the exception of liver applications, and represents an update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography.

Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease: a randomized controlled trial

The only currently recommended treatment for nonalcoholic fatty liver disease (NAFLD) is lifestyle modification. Preliminary studies of silybin showed beneficial effects on liver function. Realsil (RA) comprises the silybin phytosome complex (silybin plus phosphatidylcholine) coformulated with vitamin E. We report on a multicenter, phase III, double-blind clinical trial to assess RA in patients with histologically documented NAFLD. Patients were randomized 1:1 to RA or placebo (P) orally twice daily for 12 months. Prespecified primary outcomes were improvement over time in clinical condition, normalization of liver enzyme plasma levels, and improvement of ultrasonographic liver steatosis, homeostatic model assessment (HOMA), and quality of life. Secondary outcomes were improvement in liver histologic score and/or decrease in NAFLD score without worsening of fibrosis and plasma changes in cytokines, ferritin, and liver fibrosis markers. We treated 179 patients with NAFLD; 36 were also HCV positive. Forty-one patients were prematurely withdrawn and 138 patients analyzed per protocol (69 per group). Baseline patient characteristics were generally well balanced between groups, except for steatosis, portal infiltration, and fibrosis. Adverse events (AEs) were generally transient and included diarrhea, dysgeusia, and pruritus; no serious AEs were recorded. Patients receiving RA but not P showed significant improvements in liver enzyme plasma levels, HOMA, and liver histology. Body mass index normalized in 15% of RA patients (2.1% with P). HCV-positive patients in the RA but not the P group showed improvements in fibrogenesis markers. This is the first study to systematically assess silybin in NAFLD patients. Treatment with RA but not P for 12 months was associated with improvement in liver enzymes, insulin resistance, and liver histology, without increases in body weight. These findings warrant further investigation.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

EFSUMB Recommendations and Clinical Guidelines for Intestinal Ultrasound (GIUS) in Inflammatory Bowel Diseases

The accuracy and usefulness of gastrointestinal ultrasound (GIUS) for detecting activity and complications of inflammatory bowel diseases (IBD), has been reported in studies, promoting this technique as an important tool for the management of IBD patients. Whilst well recognised by international guidelines, standardization and general agreement in the definition of the luminal and extra-intestinal features, still need to be well defined.A task force group of 17 experts in GIUS faced this issue, by developing recommendations and clinical guidelines for the use of GIUS in IBD, under the auspices of EFSUMB. This article presents the consensus on the current data on sonographic features of IBD and summarises the accuracy of different sonographic modalities for the management of IBD patients.

Acoustic Radiation Force Impulse elastography for fibrosis evaluation in patients with chronic hepatitis C: an international multicenter study

AIM

The aim of this international multicenter study was to evaluate the reliability of Acoustic Radiation Force Impulse (ARFI) elastography for predicting fibrosis severity, in patients with chronic hepatitis C.

PATIENTS AND METHODS

We compared ARFI to liver biopsy (LB) in 914 patients (10 centers, 5 countries) with chronic hepatitis C. In each patient LB (evaluated according to the METAVIR score) and ARFI measurements were performed (median of 5-10 valid measurements, expressed in meters/second - m/s). In 400 from the 914 patients, transient elastography (TE) was also performed (median of 6-10 valid measurements, expressed in kiloPascals - kPa).

RESULTS

Valid ARFI measurements were obtained in 911 (99.6%) of 914 cases. On LB 61 cases (6.7%) had F0, 241 (26.4%) had F1, 202 (22.1%) had F2, 187 (20.4%) had F3, and 223 (24.4%) had F4 fibrosis. A highly significant correlation (r=0.654) was found between ARFI measurements and fibrosis (p<0.0001). The predictive values of ARFI for various stages of fibrosis were: F ≥ 1 - cut-off>1.19 m/s (AUROC=0.779), F ≥ 2 - cut-off>1.33 m/s (AUROC=0.792), F ≥ 3 - cut-off>1.43 m/s (AUROC=0.829), F=4 - cut-off>1.55 m/s (AUROC=0.842). The correlation with histological fibrosis was not significantly different for TE in comparison with ARFI elastography: r=0.728 vs. 0.689, p=0.28. TE was better than ARFI for predicting the presence of liver cirrhosis (p=0.01) and fibrosis (F ≥ 1, METAVIR) (p=0.01).

CONCLUSION

ARFI elastography is a reliable method for predicting fibrosis severity in chronic hepatitis C patients.

Acoustic radiation force impulse elastography as compared to transient elastography and liver biopsy in patients with chronic hepatopathies

PURPOSE

To compare two methods of noninvasive assessment: transient elastography (TE) and acoustic radiation force impulse elastography (ARFI).

PATIENTS AND METHODS

Our study included 114 subjects: 38 healthy volunteers, (considered to have no fibrosis - F 0) and 76 patients with chronic liver disease: 53 who had undergone liver biopsy (LB) (7 with F 1, 24 with F 2, 22 with F 3 Metavir) and 23 previously diagnosed with cirrhosis (F4 Metavir). In each patient we performed a liver stiffness measurement by means of TE and ARFI. ARFI (shear wave velocity quantification) was performed at 3 points: at 0 - 1 cm, at 1 - 2 cm and at 2 - 3 cm under the capsule. For each depth, 5 valid measurements were made, and a median value was calculated, measured in m/sec.

RESULTS

A direct, strong, linear correlation (Spearman rho = 0.848) was found between TE and the stage of fibrosis (p < 0.001). A significant, direct correlation was found between ARFI measurements made 1 - 2 cm and 2 - 3 cm below the liver capsule and the severity of fibrosis (rho = 0.675 and 0.714 respectively). The subcapsularly measured ARFI values showed a poor correlation with fibrosis (rho = 0.469). The best test for predicting significant fibrosis (F ≥ 2) was TE, with the area under receiver-operating characteristic curve (AUROC) 0.908, significantly larger than the AUROCs for ARFI. If only ARFI is considered, measurements made 1 - 2 and 2 - 3 cm below the capsule have the best predictive value, with AUROCs not significantly different from each other (0.767 and 0.731, respectively). For predicting fibrosis (F > 0), TE had the best predictive value: optimized cut-off 5.65 kPa (AUROC -0.898). For ARFI, the cut-offs were: 1.4 m/sec, AUROC -0.747 (1 - 2 cm), and 1.26 m/sec AUROC -0.721 (2 - 3 cm). For predicting cirrhosis (F = 4 Metavir), the optimized cut-offs were: TE -12.9 kPa (AUROC -0.994); ARFI - 1.78 m/sec for measurements made 2 - 3 cm below the capsule, AUROC - 0.951.

CONCLUSION

At present, liver elasticity evaluation by means of ARFI is not superior to TE for the assessment of liver fibrosis. For ARFI, the most reliable results are obtained if measurements are made 1 - 2 and 2 - 3 cm below the liver capsule. ARFI is an accurate test for the diagnosis of cirrhosis.

EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Short Version)

We present here the first update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography with a focus on the assessment of diffuse liver disease. The short version provides clinical information about the practical use of elastography equipment and interpretation of results in the assessment of diffuse liver disease and analyzes the main findings based on published studies, stressing the evidence from meta-analyses. The role of elastography in different etiologies of liver disease and in several clinical scenarios is also discussed. All of the recommendations are judged with regard to their evidence-based strength according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. This updated document is intended to act as a reference and to provide a practical guide for both beginners and advanced clinical users.

Value of acoustic radiation force impulse imaging elastography for non-invasive evaluation of patients with nonalcoholic fatty liver disease

The goals of the work described here were to evaluate the clinical utility of acoustic radiation force impulse (ARFI) elastography in differentiating non-alcoholic fatty liver disease (NAFLD) histologic subtypes and to determine if ARFI elastography measurements correlate with the severity of liver fibrosis. We compared ARFI elastography measurements with clinical, biologic and histologic features (simple steatosis or steatohepatitis) in 64 patients with histologically proven NAFLD. ARFI elastography is suitable for distinguishing patients with non-alcoholic steatohepatitis from those with simple steatosis, with an area under the receiver operating characteristic curve (AUROC) of 0.867 (95% confidence interval = 0.782-0.953). There was a highly significant correlation (r = 0.843) between ARFI elastography measurements and fibrosis (p < 0.001). In patients with non-alcoholic steatohepatitis, the diagnostic performance of ARFI elastography in predicting significant fibrosis (F ≥ 2) had an AUROC of 0.944. ARFI elastography better predicted F = 4 fibrosis (AUROC = 0.984). In conclusion, ARFI elastography is a promising method for differentiating patients with non-alcoholic steatohepatitis from patients with simple steatosis and can also predict significant fibrosis in these patients.

Intra- and interoperator reproducibility of acoustic radiation force impulse (ARFI) elastography--preliminary results

Our study assessed acoustic radiation force impulse (ARFI) reproducibility and the factors influencing it. The intra- and interoperator reproducibility were studied in 33 and 58 patients, respectively. Intraclass correlation coefficient (ICC) was used to assess ARFI reproducibility. The overall intraoperator agreement was better than the interoperator one: ICC 0.90 vs. ICC 0.81. The correlation of repeated ARFI measurements was higher, but not significantly so, in cases in which intraoperator reproducibility was assessed compared with the ones in which interoperator reproducibility was studied: r = 0.848 vs. r = 0.694 (p = 0.08). For both intra- and interoperator reproducibility, the ICCs were smaller in women vs. men (0.88 vs. 0.91 and 0.67 vs. 0.86, respectively), in patients with high body mass index (BMI) ≥25 kg/m² vs. <25 kg/m² (0.88 vs. 0.91 and 0.79 vs. 0.82, respectively), in patients with ascites vs. no ascites (0.80 vs. 0.93 and 0.78 vs. 0.84, respectively) and in noncirrhotic vs. cirrhotic patients (0.77 vs. 0.82 and 0.70 vs. 0.83, respectively).

Acoustic radiation force impulse and supersonic shear imaging versus transient elastography for liver fibrosis assessment

Our study compared three elastographic methods--transient elastography (TE), acoustic radiation force impulse (ARFI) imaging and supersonic shear imaging (SSI)--with respect to the feasibility of their use in liver fibrosis evaluation. We also compared the performance of ARFI imaging and SSI, with TE as the reference method. The study included 332 patients, with or without hepatopathies, in which liver stiffness was evaluated using TE, ARFI and SSI. Reliable measurements were defined as a median value of 10 (TE, ARFI imaging) or 5 (SSI) liver stiffness measurements with a success rate ≥60% and an interquartile range interval <30%. A significantly higher percentage of reliable measurements were obtained using ARFI than by using TE and SSI: 92.1% versus 72.2% (p < 0.0001) and 92.1% versus 71.3% (p < 0.0001). Higher body mass index and older age were significantly associated with inability to obtain reliable measurements of liver stiffness using TE and SSI. In 55.4% of patients, reliable liver stiffness measurements were obtained using all three elastographic methods, and ARFI imaging and TE were similarly accurate in diagnosing significant fibrosis and cirrhosis, with TE as the reference method.

How many measurements are needed for liver stiffness assessment by 2D-Shear Wave Elastography (2D-SWE) and which value should be used: the mean or median?

AIM

To analyze how many measurements are needed for non-invasive assessment of liver stiffness (LS) by means of 2D-Shear Wave Elastography (2D-SWE) and if the use of mean of median values of 2D-SWE measurements is needed.

METHODS

We evaluated 449 consecutive subjects (with or without chronic liver disease) by means of Transient Elastography (TE) and 2D-SWE. We compared the correlation of LS assessed by TE with 2D-SWE measurements when using either the median of 5 valid 2D-SWE measurements or the mean of 3 or 5 valid 2D-SWE measurements.

RESULTS

We obtained reliable LS measurements by TE in 330/449 subjects (73.5%). From these, in 281 subjects we obtained 5 valid 2D-SWE measurements. The correlation of LS assessed by TE with 2D-SWE values was similar when we used the median value of 5 valid 2D-SWE measurements, the mean value of 5 valid 2D-SWE measurements or the mean value of 3 valid 2D-SWE measurements: r =0.683, r=0.711 and r=0.691, respectively. There were no significant differences between the median value of 5 valid 2D-SWE measurements; the mean value of 5 valid 2D-SWE measurements; or the mean value of 3 valid 2D-SWE measurements: 7.6 kPa, 7.7 kPa and 7.6 kPa, respectively.

CONCLUSIONS

Our study showed that it is enough to perform 3 valid 2D-SWE measurements and to use the mean value of these measurements.

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

BACKGROUND

Acoustic Radiation Force Impulse Elastography is a new method for non-invasive evaluation of liver fibrosis.

AIM

To evaluate the impact of elevated alanine aminotransferase levels on liver stiffness assessment by Acoustic Radiation Force Impulse Elastography.

METHODS

A multicentre retrospective study including 1242 patients with chronic liver disease, who underwent liver biopsy and Acoustic Radiation Force Impulse. Transient Elastography was also performed in 512 patients.

RESULTS

The best Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis was 1.29 m/s in cases with normal alanine aminotransferase levels and 1.44 m/s in patients with alanine aminotransferase levels>5 × the upper limit of normal. The best cut-off for predicting liver cirrhosis were 1.59 and 1.75 m/s, respectively. Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis and cirrhosis were relatively similar in patients with normal alanine aminotransferase and in those with alanine aminotransferase levels between 1.1 and 5 × the upper limit of normal: 1.29 m/s vs. 1.36 m/s and 1.59 m/s vs. 1.57 m/s, respectively. For predicting cirrhosis, the Transient Elastography cut-offs were significantly higher in patients with alanine aminotransferase levels between 1.1 and 5 × the upper limit of normal compared to those with normal alanine aminotransferase: 12.3 kPa vs. 9.1 kPa.

CONCLUSION

Liver stiffness values assessed by Acoustic Radiation Force Impulse and Transient Elastography are influenced by high aminotransferase levels. Transient Elastography was also influenced by moderately elevated aminotransferase levels.