Nowadays, shear wave elastographic techniques have brought a substantial reduction of liver biopsies performed to stage liver fibrosis in patients with chronic hepatitis. The availability of accurate ...noninvasive methods for the assessment of liver fibrosis was an important breakthrough and prompted ultrasound federations of societies as well as clinical and radiologic societies to issue international guidelines or consensus statements on the clinical applications of shear wave elastographic techniques. This article reviews the guidelines that have been published as of today.
This multidisciplinary update of the Society of Radiologists in Ultrasound consensus statement on liver elastography incorporates the large volume of new information available in the literature since ...the initial publication. The recommended procedure for acquiring stiffness measurements is reviewed. There has been substantial improvement in the acoustic radiation force impulse (ARFI) technology-most notably the addition of a quality assessment of the shear wave propagation. Due to the efforts of the Quantitative Imaging Biomarkers Alliance, or QIBA, the variability of liver stiffness measurements between systems had decreased. There are now effective treatments for hepatitis B and hepatitis C, and follow-up after effective treatment should be based on the use of the delta change of the value obtained at viral eradication or suppression. Because the detection of compensated advanced chronic liver disease (cACLD) is very important, the new guidelines are made based on the probability of cACLD for given stiffness values. The panel recommends a vendor-neutral rule of four for interpretation for ARFI techniques. This new method simplifies interpretation of liver stiffness results and is more clinically relevant.
Real‐time shear wave elastography (SWE) is a novel, noninvasive method to assess liver fibrosis by measuring liver stiffness. This single‐center study was conducted to assess the accuracy of SWE in ...patients with chronic hepatitis C (CHC), in comparison with transient elastography (TE), by using liver biopsy (LB) as the reference standard. Consecutive patients with CHC scheduled for LB by referring physicians were studied. One hundred and twenty‐one patients met inclusion criteria. On the same day, real‐time SWE using the ultrasound (US) system, Aixplorer (SuperSonic Imagine S.A., Aix‐en‐Provence, France), TE using FibroScan (Echosens, Paris, France), and US‐assisted LB were consecutively performed. Fibrosis was staged according to the METAVIR scoring system. Analyses of receiver operating characteristic (ROC) curve were performed to calculate optimal area under the ROC curve (AUROC) for F0‐F1 versus F2‐F4, F0‐ F2 versus F3‐F4, and F0‐F3 versus F4 for both real‐time SWE and TE. Liver stiffness values increased in parallel with degree of liver fibrosis, both with SWE and TE. AUROCs were 0.92 (95% confidence interval CI: 0.85‐0.96) for SWE and 0.84 (95% CI: 0.76‐0.90) for TE (P = 0.002), 0.98 (95% CI: 0.94‐1.00) for SWE and 0.96 (95% CI: 0.90‐0.99) for TE (P = 0.14), and 0.98 (95% CI: 0.93‐1.00) for SWE and 0.96 (95% CI: 0.91‐0.99) for TE (P = 0.48), when comparing F0‐F1 versus F2‐ F4, F0‐ F2 versus F3‐F4, and F0 ‐F3 versus F4, respectively. Conclusion: The results of this study show that real‐time SWE is more accurate than TE in assessing significant fibrosis (≥F2). With respect to TE, SWE has the advantage of imaging liver stiffness in real time while guided by a B‐mode image. Thus, the region of measurement can be guided with both anatomical and tissue stiffness information. (HEPATOLOGY 2012;56:2125–2133)
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.
The diagnosis of liver fibrosis and the assessment of its severity are important to provide appropriate management, to determine the prognosis or the need for surveillance. Currently, for fibrosis ...staging, liver stiffness measurement (LSM) with the shear wave elastography (SWE) techniques is considered a reliable substitute for liver biopsy in several clinical scenarios. Nonetheless, it should be emphasized that stiffness value is a biomarker of diffuse liver disease that must be interpreted taking into consideration anamnesis, clinical and laboratory data. In patients with diffuse liver disease, it is more clinically relevant to determine the likelihood of advanced disease rather than to obtain an exact stage of liver fibrosis using a histologic classification. In this regard, a ‘rule of five’ for LSMs with vibration-controlled transient elastography (VCTE) and a ‘rule of four’ for LSMs with the acoustic radiation force impulse (ARFI)-based techniques have been proposed. In patients with advanced chronic liver disease (CLD), the risk of liver decompensation increases with increasing liver stiffness value. SWE has been proposed as a tool to predict the risk of death or complications in patients with CLD. LSM by VCTE combined with platelets count is a validated non-invasive method for varices screening, with very good results in terms of invasive procedures being spared. ARFI-based techniques also show some promising results in this setting. LSM, alone or combined in scores or algorithms with other parameters, is used to evaluate the risk of hepatocellular carcinoma occurrence. Due to the high prevalence of CLD, screening the population at risk is of interest but further studies are needed.
AIM:To estimate the validity of the point shear-wave elastography method by evaluating its reproducibility and accuracy for assessing liver stiffness.METHODS:This was a single-center,cross-sectional ...study.Consecutive patients with chronic viral hepatitis scheduled for liver biopsy(LB)(Group 1)and healthy volunteers(Group 2)were studied.In each subject 10 consecutive point shear-wave elastography(PSWE)measurements were performed using the iU22 ultrasound system(Philips Medical Systems,Bothell,WA,United States).Patients in Group 1 underwent PSWE,transient elastography(TE)using FibroScan(Echosens,Paris,France)and ultrasound-assisted LB.For the assessment of PSWE reproducibility two expert raters(rater 1 and rater 2)independently performed the examinations.The performance of PSWE was compared to that of TE using LB as a reference standard.Fibrosis was staged according to the METAVIR scoring system.Receiver operating characteristic curve analyses were performed to calculate the area under the receiver operating characteristic curve(AUC)for F≥2,F≥3and F=4.The intraobserver and interobserver reproducibility of PSWE were assessed by calculating Lin’s concordance correlation coefficient.RESULTS:To assess the performance of PSWE,134consecutive patients in Group 1 were studied.The median values of PSWE and TE(in kilopascals)were 4.7(IQR=3.8-5.4)and 5.5(IQR=4.7-6.5),respectively,in patients at the F0-F1 stage and 3.5(IQR=3.2-4.0)and 4.4(IQR=3.5-4.9),respectively,in the healthy volunteers in Group 2(P<10-5).In the univariate analysis,the PSWE and TE values showed a high correlation with the fibrosis stage;low correlations with the degree of necroinflammation,aspartate aminotransferase and gamma-glutamyl transferase(GGT);and a moderate negative correlation with the platelet count.A multiple regression analysis confirmed the correlations of both PSWE and TE with fibrosis stage and GGT but not with any other variables.The following AUC values were found:0.80(0.71-0.87)for PSWE and 0.82(0.73-0.89)for TE(P=0.42);0.88(0.80-0.94)for PSWE and 0.95(0.88-0.98)for TE(P=0.06);and 0.95(0.89-0.99)for PSWE and 0.92(0.85-0.97)for TE(P=0.30)for F≥2,F≥3 and F=4,respectively.To assess PSWE reproducibility,116 subjects were studied,including 47consecutive patients scheduled for LB(Group 1)and 69 consecutive healthy volunteers(Group 2).The intraobserver agreement ranged from 0.83(95%CI:0.79-0.88)to 0.96(95%CI:0.95-0.97)for rater 1 and from 0.84(95%CI:0.79-0.88)to 0.96(95%CI:0.95-0.97)for rater 2.The interobserver agreement yielded values from0.83(95%CI:0.78-0.88)to 0.93(95%CI:0.91-0.95).CONCLUSION:PSWE is a reproducible method for assessing liver stiffness,and it compares with TE.Compared with patients with nonsignificant fibrosis,healthy volunteers showed significantly lower values.
The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, hepatology, pathology, and basic science and physics to arrive at a consensus regarding the use of ...elastography in the assessment of liver fibrosis in chronic liver disease. The panel met in Denver, Colo, on October 21-22, 2014, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to the noninvasive assessment of diffuse liver fibrosis.
Objectives
The main aim was to assess the performance and cutoff value for the detection of liver steatosis (grade S > 0) with the Attenuation Imaging–Penetration (ATI‐Pen) algorithm available on the ...Aplio i‐series ultrasound systems (Canon Medical Systems, Otawara, Japan). The magnetic resonance imaging–derived proton density fat fraction (MRI‐PDFF) was used as the reference standard. Secondary aims were to compare the results to those obtained with the previous ATI algorithm (Attenuation Imaging–General ATI‐Gen) and with the controlled attenuation parameter (CAP) and to generate a regression equation between ATI‐Pen and ATI‐Gen values.
Methods
Consecutive adult patients potentially at risk of liver steatosis were prospectively enrolled. Each patient underwent ultrasound quantification of liver steatosis with ATI‐Pen and ATI‐Gen and a CAP assessment with the FibroScan system (Echosens, Paris, France). The MRI‐PDFF evaluation was performed within a week. The correlations between ATI‐Pen, ATI‐Gen, the CAP, and the MRI‐PDFF were analyzed with the Pearson rank correlation coefficient. The diagnostic performance of ATI‐Pen, ATI‐Gen, and the CAP was assessed with receiver operating characteristic curves and an area under the receiver operating characteristic curve (AUROC) analysis.
Results
Seventy‐two individuals (31 male and 41 female) were enrolled. Correlation coefficients of ATI‐Pen, ATI‐Gen, and the CAP with the MRI‐PDFF were 0.78, 0.83, and 0.58, respectively. The AUROCs of ATI‐Pen, ATI‐Gen, and the CAP for detecting steatosis (S > 0) were 0.90 (95% confidence interval, 0.81–0.96), 0.92 (0.82–0.98), and 0.85 (0.74–0.92), and the cutoffs were greater than 0.69 dB/cm/MHz, greater than 0.62 dB/cm/MHz, and greater than 273 dB/m. The regression equation between ATI‐Pen and ATI‐Gen was ATI‐Pen = 0.88 ATI‐Gen + 0.13.
Conclusions
Attenuation Imaging is a reliable tool for detecting liver steatosis, showing an excellent correlation with the MRI‐PDFF and high performance with AUROCs of 0.90 or higher.
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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).
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