Optimal linear combination of ARFI, transient elastography and APRI for the assessment of fibrosis in chronic hepatitis B

Staging liver fibrosis and cirrhosis using non-invasive tests in people with chronic hepatitis B to inform WHO 2024 guidelines: a systematic review and meta-analysis

BACKGROUND

Non-invasive tests (aspartate aminotransferase-to-platelet ratio index [APRI] and transient elastography [FibroScan]) were recommended in the 2015 WHO guidelines to guide treatment decisions in people with chronic hepatitis B. We updated the systematic review and meta-analysis that informed the 2015 guidelines to inform new cutoffs for non-invasive tests for the diagnosis of significant fibrosis and cirrhosis for the 2024 WHO guidelines for chronic hepatitis B.

METHODS

We searched PubMed (MEDLINE), Embase, and Science Citation Index Expanded (Web of Science) for studies published in any language between Jan 1, 2014, and Feb 15, 2023. We included all studies that reported cross-sectional data on the staging of fibrosis or cirrhosis with APRI, Fibrosis-4 (FIB-4), and FibroScan compared with liver biopsy as the reference standard in people with chronic hepatitis B. We excluded studies in which the maximum interval between liver biopsy and non-invasive fibrosis test was more than 6 months; that reported on fewer than ten patients with advanced fibrosis or cirrhosis; that were done exclusively in children; and did not report diagnostic accuracy across our prespecified ranges of test cutoffs. The results of this updated search were collated with the meta-analysis that informed the 2015 guidelines. Outcomes of interest were the sensitivity and specificity of non-invasive tests using defined index test cutoffs for detecting significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) based on the METAVIR staging system. We performed meta-analyses using a bivariate random-effects model.

FINDINGS

Of 19 933 records identified by our search strategy, 195 were eligible for our systematic review and combined with the 69 studies from the previous meta-analysis to total 264. Two studies were at low risk of bias, 31 studies had unclear risk of bias, and 231 studies had a high risk of bias. Of these 264, 211 studies with 61 665 patients were used in the meta-analysis. For the diagnosis of significant fibrosis (≥F2), sensitivity and specificity were 72·9% (95% CI 70·2-75·5) and 64·7% (95% CI 61·0-68·2) for the APRI low cutoff (>0·3 to 0·7), 30·5% (23·7-38·3) and 92·3% (89·3-94·6) for the APRI high cutoff (>1·3 to 1·7), and 75·1% (72·2-77·7) and 79·3% (76·2-82·2) for FibroScan (>6·0 to 8·0 kPa), respectively. For the diagnosis of cirrhosis (F4), sensitivity and specificity were 59·4% (53·2-65·2) and 73·9% (70·1-77·4) for the APRI low cutoff (>0·8 to 1·2), 30·2% (24·2-36·9) and 88·2% (85·4-90·6) for the APRI high cutoff (>1·8 to 2·2), and 82·6% (77·8-86·5) and 89·0% (86·3-91·2) for FibroScan (>11·0 to 14·0 kPa), respectively. Using a hypothetical population of 1000 unselected patients with chronic hepatitis B with a 25% prevalence of significant fibrosis (≥F2), the APRI low cutoff for significant fibrosis (≥F2) would result in 262 (26·2%) false positives but only 68 (6·8%) false negatives. The FibroScan cutoff would result in 158 (15·8%) false positives and 63 (6·3%) false negatives. In a population with a 5% prevalence of cirrhosis (F4), the APRI low cutoff for cirrhosis (F4) would result in 247 (24·7%) false positives and 21 (2·1%) false negatives and the FibroScan cutoff would result in 105 (10·5%) false positives and nine (0·9%) false negatives.

INTERPRETATION

These findings have informed new thresholds of APRI and FibroScan for diagnosis of significant fibrosis and cirrhosis in the 2024 WHO guidelines on chronic hepatitis B, with an APRI score greater than 0·5 or a FibroScan value greater than 7·0 kPa considered to identify most adults with significant fibrosis (≥F2) and an APRI score greater than 1·0 or a FibroScan value greater than 12·5 kPa to identify most adults with cirrhosis (F4). These patients are a priority for antiviral treatment.

FUNDING

WHO.

Diagnostic accuracy of magnetic resonance elastography and point-shear wave elastography for significant hepatic fibrosis screening: Systematic review and meta-analysis

The hepatic diseases are extremely common in clinical practice. The correct classification of liver fibrosis is extremely important, as it influences therapy and predicts disease outcomes. The purpose of this study is to compare the diagnostic performance of point-shear wave elastography (pSWE) and magnetic resonance elastography (MRE) in the hepatic fibrosis diagnostic. A meta-analysis was carried out based on articles published until October 2020. The articles are available at following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, LILACS, Scopus, and CINAHL. Diagnostic performances were analyzed per METAVIR F2, using 3.5kPa as target fibrosis. Assessment of the methodological quality of the incorporated papers by the QUADAS-2 tool for pSWE and MRE. A total 2,153 studies articles were evaluated and 44 studies, comprising 6,081 patients with individual data, were included in the meta-analysis: 28 studies for pSWE and 16 studies for MRE. The pooled sensitivity and specificity were 0.86 (95%CI 0.80-0.90) and 0.88 (95%CI 0.85-0.91), respectively, for pSWE, compared with 0.94 (95%CI 0.89-0.97) and 0.95 (95%CI 0.89-0.98) respectively, for MRE. The pooled SROC curve for pSWE shows in the area under the curve (AUC) of 0.93 (95%CI 0.90-0.95), whereas the AUC for MRE was 0.98 (95%CI 0.96-0.99). The diagnostic odds ratio for pSWE and MRE were 41 (95%CI 24-72) and 293 (95%CI 86-1000), respectively. There was statistically significant heterogeneity for pSWE sensitivity (I² = 85.26, P<0.001) and specificity (I² = 89.46, P<0.001). The heterogeneity for MRE also was significant for sensitivity (I² = 73.28, P<0.001) and specificity (I² = 87.24, P<0.001). Therefore, both pSWE and MRE are suitable modalities for assessing liver fibrosis. In addition, MRE is a more accurate imaging technique than pSWE and can be used as alternative to invasive biopsy.

Ultrasound-New Techniques Are Extending the Applications

BACKGROUND

Sonography is often the first imaging procedure to be used in diagnostic investigation of the abdomen. The aim of this article is to provide a new interdisciplinary overview of recent groundbreaking advances in this modality.

METHODS

A selective survey of the literature in PubMed was conducted. The literature search was carried out in 2021-2022 and included publications over the period 2004-2022.

RESULTS

The novel sonographic software techniques can be divided into algorithms that deal with conventional B-scan optimization and new programs that extend the scope of sonographic examination. The latter include elastography, contrast-enhanced sonography, and image fusion in combination with other cross-sectional imaging modalities. Elastography can be used to assess the presence of steatosis, fibrosis, or cirrhosis in patients with liver disease. One study reported diagnostic accuracy of 84-87% for the diagnosis of significant fibrosis (F2), 89-91% for the diagnosis of severe fibrosis (F3), and 92-93% for the diagnosis of liver cirrhosis (F4). Contrast-enhanced sonography is used for evaluation of tumors and trauma. A prospective multicenter study found sensitivity of 95.8% for the characterization of malignant lesions and specificity of 83.1% for benign lesions. Image fusion has the potential to improve the diagnostic assessment of parenchymatous organs, vascular conditions, and the prostate.

CONCLUSION

With continuous improvement of the B-scan and the development of high-frequency probes and novel investigation techniques, sonography has become established as an increasingly autonomous examination procedure.

Comparison of two-dimensional shear wave elastography, magnetic resonance elastography, and three serum markers for diagnosing fibrosis in patients with chronic hepatitis B: a meta-analysis

BACKGROUND

Two-dimensional shear wave elastography (2D-SWE), magnetic resonance elastography (MRE), aspartate transaminase-to-platelet ratio index (APRI), fibrosis index based on 4 factors (FIB-4), and King's score have been proposed for diagnosing fibrosis.

METHODS

Literature databases were searched until October 1st, 2020. The summary area under the receiver operating characteristic curve (AUROC), the summary diagnostic odds ratios, and the summary sensitivities and specificities were used to assess the performance of these noninvasive methods for staging fibrosis.

RESULTS

Our final data contained 72 studies. The prevalence of significant fibrosis, advanced fibrosis, and cirrhosis was 58.3%, 36.2%, and 20.5%, respectively, in chronic hepatitis B (CHB). For 2D-SWE and MRE, the summary AUROCs were 0.89 and 0.97, 0.95 and 0.97, and 0.94 and 0.97 for significant fibrosis, advanced fibrosis, and cirrhosis, respectively. The summary AUROCs using APRI and FIB-4 for detecting significant fibrosis, advanced fibrosis, and cirrhosis were 0.76 and 0.75, 0.74 and 0.77, and 0.77 and 0.82, respectively. The summary AUROCs of King's score for detecting significant fibrosis and cirrhosis were 0.77 and 0.83, respectively.

CONCLUSION

MRE and 2D-SWE may show the best diagnostic accuracy for predicting fibrosis in CHB. Among the three serum markers, King's score may be more useful for diagnosing fibrosis.

Combining hepatic surface nodularity and serum tests better predicts hepatic fibrosis stages in chronic liver disease

PURPOSE

Hepatic surface nodularity quantified on CT images has shown promising results in staging hepatic fibrosis in chronic hepatitis C. The aim of this study was to evaluate hepatic surface nodularity, serum fibrosis indices, and a linear combination of them for staging fibrosis in chronic liver disease, mainly chronic hepatitis B.

METHODS

We developed a semiautomated software quantifying hepatic surface nodularity on CT images. Hepatic surface nodularity and serum fibrosis indices were assessed in the development group of 125 patients to generate 3 linear models combining hepatic surface nodularity with the aspartate aminotransferase to platelet ratio index, fibrosis-4 index, or platelet count in reference to the METAVIR scoring system. The models were validated in 183 patients.

RESULTS

Hepatic surface nodularity and serum fibrosis indices all significantly correlated with fibrosis stages. For binary classifications into cirrhosis (F4), advanced fibrosis (≥ F3), and significant fibrosis (≥ F2), hepatic surface nodularity was significantly different across categories. The areas under the curve (AUCs) of the best model were 0.901, 0.872, and 0.794 for cirrhosis, advanced fibrosis, and significant fibrosis, respectively, higher than serum fibrosis indices alone (0.797-0.802, 0.799-0.818, and 0.761-0.773). In the validation group, the same model likewise showed higher AUCs (0.872, 0.831, and 0.850) compared to serum fibrosis indices (0.722-0.776, 0.692-0.768, and 0.695-0.769; p < 0.001 for F4).

CONCLUSION

Hepatic surface nodularity combined with serum blood test could be a practical method to predict cirrhosis, advanced fibrosis, and significant fibrosis in chronic liver disease patients, providing higher accuracy than using serum fibrosis indices alone.

Comparing radiomics models with different inputs for accurate diagnosis of significant fibrosis in chronic liver disease

OBJECTIVE

The non-invasive discrimination of significant fibrosis (≥ F2) in patients with chronic liver disease (CLD) is clinically critical but technically challenging. We aimed to develop an updated deep learning radiomics model of elastography (DLRE2.0) based on our previous DLRE model to achieve significantly improved performance in ≥ F2 evaluation.

METHODS

This was a retrospective multicenter study with 807 CLD patients and 4842 images from three hospitals. All of these patients have liver biopsy results as referenced standard. Multichannel deep learning radiomics models were developed. Elastography images, gray-scale images of the liver capsule, gray-scale images of the liver parenchyma, and serological results were gradually integrated to establish different diagnosis models, and the optimal model was selected for assessing ≥ F2. Its accuracy was thoroughly investigated by applying different F0-1 prevalence cohorts and independent external test cohorts. Analysis of receiver operating characteristic (ROC) curves was performed to calculate the area under the ROC curve (AUC) for significance of fibrosis (≥ F2) and cirrhosis (F4).

RESULTS

The AUC of the DLRE2.0 model significantly increased to 0.91 compared with the DLRE model (AUC 0.83) when evaluating ≥ F2 (p = 0.0167). However, it did not show statistically significant differences as integrating gray-scale images and serological data into the DLRE2.0 model. AUCs of DLRE and DLRE2.0 increased, when there was higher F0-1 prevalence. All radiomics models had good robustness in the independent external test cohort.

CONCLUSIONS

DLRE2.0 was the most suitable model for staging significant fibrosis while considering the balance of diagnostic accuracy and clinical practicability.

KEY POINTS

• The non-invasive discrimination of significant fibrosis (≥ F2) in patients with chronic liver disease (CLD) is clinically critical but technically challenging. • We aimed to develop an updated deep learning radiomics model of elastography (DLRE2.0) based on our previous DLRE model to achieve significantly improved performance in ≥ F2 evaluation. • Our study based on 807 CLD patients and 4842 images with liver biopsy found that DLRE2.0 was the most suitable model for staging significant fibrosis while considering the balance of diagnostic accuracy and clinical practicability.

Comparison of 2-D Shear Wave Elastography and Point Shear Wave Elastography for Assessing Liver Fibrosis

Progressive liver fibrosis may result in cirrhosis, portal hypertension and increased risk of hepatocellular carcinoma. We performed a meta-analysis to compare liver fibrosis staging in chronic liver disease patients using 2-D shear wave elastography (2-D SWE) and point shear wave elastography (pSWE). The PubMed, Web of Science and Cochrane Library databases were searched until May 31, 2020 for studies evaluating the diagnostic performance of 2-D SWE and pSWE in assessing liver fibrosis. Pooled sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratios and area under receiver operating characteristic curve were estimated using the bivariate random effects model. As a result, 71 studies with 11,345 patients were included in the analysis. The pooled sensitivities of 2-D SWE and pSWE significantly differed for the detection of significant fibrosis (F ≥ 2; 0.84 vs. 0.76, p < 0.001) and advanced fibrosis (F ≥ 3; 0.90 vs. 0.83, p = 0.003), but not for detection of cirrhosis (F = 4; 0.89 vs. 0.85, p = 0.090). The pooled specificities of 2-D SWE and pSWE did not significantly differ for detection of F ≥ 2 (0.81 vs. 0.79, p = 0.753), F ≥ 3 (0.87 vs. 0.83, p = 0.163) or F = 4 (0.87 vs. 0.84, p = 0.294). Both 2-D SWE and pSWE have high sensitivity and specificity for detecting each stage of liver fibrosis. Two-dimensional SWE has higher sensitivity than pSWE for detection of significant fibrosis and advanced fibrosis.

Ultrasound-based liver elastography in the assessment of fibrosis

Ultrasound-based elastography has rapidly replaced the need for liver biopsy in most patients with chronic liver disease in recent years. The technique is now widely supported by many manufacturers. This review will introduce various current ultrasound-based elastography techniques, review the physics and scanning techniques, discuss potential cofounding factors as well as summarising the evidence for its use in staging liver fibrosis using shear-wave elastography among different disease aetiologies. Future challenges and directions will be also be discussed.

Performance of common imaging techniques vs serum biomarkers in assessing fibrosis in patients with chronic hepatitis B: A systematic review and meta-analysis

BACKGROUND

Noninvasive biomarkers have been developed to predict hepatitis B virus (HBV) related fibrosis owing to the significant limitations of liver biopsy. Both serum biomarkers and imaging techniques have shown promising results and may improve the evaluation of liver fibrosis. However, most of the previous studies focused on the diagnostic effects of various imaging techniques on fibrosis in all chronic liver diseases.

AIM

To compare the performance of common imaging methods and serum biomarkers for prediction of significant fibrosis caused only by HBV infection.

METHODS

A systematic review was conducted on the records available in PubMed, EMBASE, and the Cochrane Library electronic databases until December 2018. We systematically assessed the effectiveness of two serum biomarkers and three imagine techniques in predicting significant fibrosis solely caused by HBV infection. The serum biomarkers included aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis index based on the 4 factors (FIB-4). The three imaging techniques included acoustic radiation force impulse (ARFI), FibroScan, and magnetic resonance elastography (MRE). Three parameters, the area under the summary receiver operating characteristic curve (AUSROC), the summary diagnostic odds ratio, and the summary sensitivity and specificity, were used to examine the accuracy of all tests for liver fibrosis.

RESULTS

Out of 2831 articles evaluated for eligibility, 204 satisfied the predetermined inclusion criteria for this current meta-analysis. Eventually, our final data contained 81 studies. The AUSROCs of serum biomarkers of APRI and FIB-4 were both 0.75. For imaging techniques (ARFI, FibroScan, and MRE), the areas were 0.89, 0.83, and 0.97, respectively. The heterogeneities of ARFI and FibroScan were statistically significant (I² > 50%). The publication bias was not observed in any of the serum biomarkers or imaging methods.

CONCLUSION

These five methods have attained an acceptable level of diagnostic accuracy. Imaging techniques, MRE in particular, demonstrate significant advantages in accurately predicting HBV-related significant fibrosis, while serum biomarkers are admissible methods.

Derivation and Performance of Standardized Enhanced Liver Fibrosis (ELF) Test Thresholds for the Detection and Prognosis of Liver Fibrosis

INTRODUCTION

Noninvasive tests are increasingly used to assess liver fibrosis and determine prognosis but suggested test thresholds vary. We describe the selection of standardized thresholds for the Enhanced Liver Fibrosis (ELF) test for the detection of liver fibrosis and for prognostication in chronic liver disease.

METHODS

A Delphi method was used to identify thresholds for the ELF test to predict histological liver fibrosis stages, including cirrhosis, using data derived from 921 patients in the EUROGOLF cohort. These thresholds were then used to determine the prognostic performance of ELF in a subset of 457 patients followed for a mean of 5 years.

RESULTS

The Delphi panel selected sensitivity of 85% for the detection of fibrosis and >95% specificity for cirrhosis. The corresponding thresholds were 7.7, 9.8, and 11.3. Eighty-five percent of patients with mild or worse fibrosis had an ELF score ≥7.7. The sensitivity for cirrhosis of ELF ≥9.8 was 76%. ELF ≥11.3 was 97% specific for cirrhosis. ELF scores show a near-linear relationship with Ishak fibrosis stages. Relative to the <7.7 group, the hazard ratios for a liver-related outcome at 5 years were 21.00 (95% CI, 2.68-164.65) and 71.04 (95% CI, 9.4-536.7) in the 9.8 to <11.3 and ≥11.3 subgroups, respectively.

CONCLUSION

The selection of standard thresholds for detection and prognosis of liver fibrosis is described and their performance reported. These thresholds should prove useful in both interpreting and explaining test results and when considering the relationship of ELF score to Ishak stage in the context of monitoring.

Acoustic Radiation Force Impulse Elastography with APRI and FIB-4 to Identify Significant Liver Fibrosis in Chronic Hepatitis B Patients

INTRODUCTION AND AIM

In chronic hepatitis B (CHB) patients with equivocal indication for antiviral therapy, therapeutic decision currently depends on histopathology of the liver. We aimed to evaluate if acoustic radiation force impulse (ARFI) in conjunction with aspartate transaminase to platelet ratio index (APRI) and fibrosis-4 (FIB-4) score could replace liver biopsy to indicate treatment for CHB.

MATERIAL AND METHODS

We prospectively enrolled 101 clinically non-cirrhotic patients whose serum alanine aminotransferase was mildly elevated (1-2 folds above the upper normal limit) despite a high viral load (HBV DNA &gt; 2,000 IU/mL). All participants underwent liver biopsy, and measurement of ARFI, APRI and FIB-4. The ability of the markers to distinguish fibrosis ≥ METAVIR F2 was evaluated.

RESULTS

According to histopathology, liver fibrosis was METAVIR F0 in 2 (2.0%), F1 in 43 (42.6%), F2 in 34 (33.7%), F3 in 16 (15.8%), and F4 in 6 (5.9%) patients, and was correlated with ARFI (p = 0.0001), APRI (p = 0.012), and FIB-4 (p = 0.004). The six patients with cirrhosis were included for analysis, and received antiviral therapy. The C statistics of ARFI, APRI, and FIB-4 for fibrosis ≥ F2 were 0.70 (95% confidence interval [CI], 0.59-0.80), 0.62 (95% CI, 0.51-0.73), and 0.64 (0.53- 0.75), respectively. The cut-off values for 95% sensitivity and 95% specificity to identify significant fibrosis were 0.97 m/sec and 1.36 m/sec for ARFI, 0.36 and 1.0 for APRI, 0.63 and 2.22 for FIB-4, respectively. Using a combination of these 3 indices, 44 patients (43.6%) could be spared a liver biopsy procedure.

CONCLUSIONS

A combination of ARFI, APRI, and FIB-4 may spare some CHB patients with equivocal indication for antiviral treatment a liver biopsy.

Role of acoustic radiation force impulse imaging elastography in the assessment of steatohepatitis and fibrosis in rat models

Acoustic radiation force impulse (ARFI) elastography is a non-invasive method for performing liver assessment via liver shear wave velocity (SWV) measurements. The aim of this study was to evaluate the performance of the ARFI technique in the diagnosis of nonalcoholic steatohepatitis (NASH) and fibrosis and to investigate the effect of steatosis and inflammation on liver fibrosis SWV measurements in a rat model of nonalcoholic fatty liver disease (NAFLD). The ex vivo right liver lobes from 110 rats were processed and embedded in a fabricated gelatin phantom, and the other lobes were used for histologic assessment. The SWV induced by acoustic radiation force was derived to evaluate liver stiffness. The experimental results showed that the liver SWV value could be used to differentiate non-NASH rats from NASH-presenting rats and NASH from cirrhosis, and these comparisons showed areas under the receiver operating characteristic curves (AUROC) of 0.951 and 0.980, respectively. The diagnostic performances of ARFI elastography in predicting severe fibrosis (F ≥ 3) and cirrhosis (F ≥ 4) showed AUROC values of 0.997 and 0.993, respectively. In rats with mild fibrosis (F0-F1), severe steatosis had a significant effect on the mean SWV values. In rats with significant fibrosis (F2-F4), severe lobular inflammation had significant effects on the mean SWV values. Our findings indicate that ARFI elastography is a promising method for differentiating non-NASH rats from NASH rats and for staging hepatic fibrosis in NASH. The presence of severe steatosis and severe lobular inflammation are significant factors for evaluating fibrosis stages.

Acoustic Radiation Force Impulse US Imaging: Liver Stiffness in Patients with Chronic Hepatitis B with and without Antiviral Therapy

Purpose To investigate the clinical utility and longitudinal change of acoustic radiation force impulse (ARFI) ultrasonographic (US) imaging in patients with chronic hepatitis B. Materials and Methods A retrospective cohort study of patients with chronic hepatitis B who underwent serial ARFI examinations in a tertiary referral center in Taiwan between 2012 and 2016 was conducted. The clinical information and noninvasive liver stiffness measurement tests (ARFI, Fibrosis-4 index [FIB-4], and FibroScan) were collected. Serial ARFI measurements were compared in patients without antiviral therapy (nontreatment group) and during antiviral therapy (treatment group). The linear mixed-effects model with random coefficients was used to compare longitudinal repeated measurements. Results A total of 559 patients undergoing serial ARFI examinations were included. The ARFI value correlated with FIB-4 (correlation coefficient = 0.55, P < .001) and FibroScan (correlation coefficient = 0.69, P < .001) results. There were 314 patients with five or more ARFI measurements in more than 3 years of follow-up. The ARFI value remained unchanged in the nontreatment group (n = 189, from 1.11 to 1.11 m/sec, time trend P = .911). However, the ARFI value declined significantly in the treatment group (n = 125, from 1.63 to 1.37 m/sec, time trend P < .001), both in patients with cirrhosis (n = 51, from 2.15 to 1.75 m/sec, time trend P < .001) and in those without (n = 74, from 1.27 to 1.11 m/sec, time trend P < .001). Conclusion ARFI US imaging is an important clinical noninvasive test for liver stiffness measurement and can be used for serial measurements in the management of chronic hepatitis B. Antiviral therapy significantly reduces liver stiffness during longitudinal follow-up.

Quantitative Elastography Methods in Liver Disease: Current Evidence and Future Directions

Chronic liver diseases often result in the development of liver fibrosis and ultimately, cirrhosis. Treatment strategies and prognosis differ greatly depending on the severity of liver fibrosis, thus liver fibrosis staging is clinically relevant. Traditionally, liver biopsy has been the method of choice for fibrosis evaluation. Because of liver biopsy limitations, noninvasive methods have become a key research interest in the field. Elastography enables the noninvasive measurement of tissue mechanical properties through observation of shear-wave propagation in the tissue of interest. Increasing fibrosis stage is associated with increased liver stiffness, providing a discriminatory feature that can be exploited by elastographic methods. Ultrasonographic (US) and magnetic resonance (MR) imaging elastographic methods are commercially available, each with their respective strengths and limitations. Here, the authors review the technical basis, acquisition techniques, and results and limitations of US- and MR-based elastography techniques. Diagnostic performance in the most common etiologies of chronic liver disease will be presented. Reliability, reproducibility, failure rate, and emerging advances will be discussed. ^© RSNA, 2018 Online supplemental material is available for this article.

Development of a Simple Noninvasive Model to Predict Significant Fibrosis in Patients with Chronic Hepatitis B: Combination of Ultrasound Elastography, Serum Biomarkers, and Individual Characteristics

Objectives:

The accurate assessment of liver fibrosis is clinically important in patients with chronic hepatitis B (CHB). Blood tests and elastography are now widely used for the noninvasive diagnosis of liver fibrosis in CHB patients. The aim of this study was to develop a new and more accurate predictive model, which combines elastography data, serum biomarkers, and individual characteristics, to discriminate between CHB patients with and without significant liver fibrosis.

Methods:

Two noninvasive methods, specifically, an ultrasound elastography technique termed acoustic radiation force impulse imaging (ARFI) and a blood test, were used to assess a cohort of 345 patients (estimation group, 218 patients; validation group, 127 patients) with CHB. Multivariate logistic regression analysis revealed that ARFI, the aspartate aminotransferase (AST) to platelet ratio, and age were significantly associated with fibrosis. Based on these results, we constructed and validated a model for the diagnosis of significant hepatic fibrosis.

Results:

The area under the receiver operating characteristic (ROC) curve was 0.921 for the estimation group and 0.929 for the validation group, significantly higher than those for ARFI (0.887, 0.893) and for the AST-to-platelet ratio index (APRI; 0.811, 0.859). Using an optimal cutoff of 3.05 in the validation group, all the indices of the proposed model, including accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic odds ratio, were better than those for ARFI or APRI.

Conclusions:

We developed a simple noninvasive model that used ultrasound elastography, routine serum biomarkers, and individual characteristics to accurately differentiate significant fibrosis in patients with CHB. Compared with elastography or the biomarker index alone, this model was significantly more accurate and robust.

Virtual Touch™ Quantification to Diagnose and Monitor Liver Fibrosis in Hepatitis B and Hepatitis C: A NICE Medical Technology Guidance

Virtual Touch™ Quantification (VTq) is a software application used with Siemens Acuson ultrasound scanners to assess the stiffness of liver tissue. The National Institute for Health and Care Excellence (NICE) Medical Technologies Advisory Committee (MTAC) selected VTq for evaluation and invited the company to submit clinical and economic evidence. King's Technology Evaluation Centre, an External Assessment Centre (EAC) commissioned by NICE, independently assessed the evidence submitted. The EAC conducted its own systematic review, meta-analysis and economic analysis to supplement the company's submitted evidence. The meta-analyses comparing VTq and transient elastography (TE) with liver biopsy (LB) provided pooled estimates of liver stiffness and stage of fibrosis for the study populations (hepatitis B, hepatitis C or combined populations). When comparing significant fibrosis (Metavir score F ≥ 2) for both hepatitis B and C, VTq had slightly higher values for both sensitivity and specificity (77 and 81 %) than TE (76 and 71 %). The overall prevalence of cirrhosis (F4, combined populations) was similar with VTq and TE (23 vs. 23 %), and significant fibrosis (F ≥ 2) was lower for VTq than for TE (55 vs. 62 %). The EAC revised the company's de novo cost model, which resulted in a cost saving of £53 (against TE) and £434 (against LB). Following public consultation, taking into account submitted comments, NICE Medical Technology Guidance MTG27 was published in September 2015. This recommended the adoption of the VTq software to diagnose and monitor liver fibrosis in patients with hepatitis B or hepatitis C.

Noninvasive Assessment of Liver Fibrosis Stage Using Ultrasound-Based Shear Wave Velocity Measurements and Serum Algorithms in Patients With Viral Hepatitis B: A Retrospective Cohort Study

OBJECTIVES

Liver biopsy remains the reference standard for the assessment of liver fibrosis, but this procedure is invasive and can lead to complications. Thus, studies to determine the optimal noninvasive test are warranted. This study compared several noninvasive tests and their combinations for evaluating liver fibrosis stages in patients with chronic hepatitis B.

METHODS

The shear wave velocity (SWV) and laboratory indicators were collected from 174 patients with chronic hepatitis B. Formulas were applied to calculate the serum fibrosis model, including the aspartate aminotransaminase-to-platelet ratio index (APRI), fibrosis-4 index (FIB-4) and aspartate aminotransferase-to-alanine aminotransferase ratio (AAR). The diagnostic performance of all noninvasive tests was assessed in comparison with percutaneous liver biopsy, based on a receiver operating characteristic curve analysis.

RESULTS

The SWV (area under the receiver operating characteristic curve [AUC], 0.82) and APRI (AUC = 0.77) performed better than the FIB-4 (AUC = 0.62), and the AAR (AUC = 0.47) was not suitable for evaluating substantial liver fibrosis (stage ≥F2). The SWV (AUC = 0.96) was the best indicator, being superior to the APRI (AUC = 0.75) and FIB-4 (AUC = 0.74), and the AAR (AUC = 0.45) was not suitable for assessing cirrhosis (F4). Combining the SWV and APRI, the AUC improved to 0.85 for substantial liver fibrosis, and the sensitivity increased to 100% for cirrhosis.

CONCLUSIONS

The SWV, APRI, and FIB-4 were valid tests for evaluating substantial liver fibrosis and cirrhosis. The combination of these tests with several noninvasive indicators is expected to enhance the assessment of liver fibrosis stages.

Viscoelastic properties of normal rat liver measured by ultrasound elastography: Comparison with oscillatory rheometry

BACKGROUND

Ultrasound elastography has been widely used to measure liver stiffness. However, the accuracy of liver viscoelasticity obtained by ultrasound elastography has not been well established.

OBJECTIVE

To assess the accuracy of ultrasound elastography for measuring liver viscoelasticity and compare to conventional rheometry methods. In addition, to determine if combining these two methods could delineate the rheological behavior of liver over a wide range of frequencies.

METHODS

The phase velocities of shear waves were measured in livers over a frequency range from 100 to 400 Hz using the ultrasound elastography method of shearwave dispersion ultrasound vibrometry (SDUV), while the complex shear moduli were obtained by rheometry over a frequency range of 1 to 30 Hz. Three rheological models, Maxwell, Voigt, and Zener, were fit to the measured data obtained from the two separate methods and from the combination of the two methods.

RESULTS

The elasticity measured by SDUV was in good agreement with that of rheometry. However, the viscosity measured by SDUV was significantly different from that of rheometry.

CONCLUSIONS

The results indicate that the high frequency components of the dispersive data play a much more important role in determining the dispersive pattern or the viscous value than the low frequency components. It was found that the Maxwell model is not as appropriate as the Voigt and Zener models for describing the rheological behavior of liver.

Noninvasive models for assessment of liver fibrosis in patients with chronic hepatitis B virus infection

There are approximately 240 million patients with chronic hepatitis B virus (HBV) infection worldwide. Up to 40% of HBV-infected patients can progress to liver cirrhosis, hepatocellular carcinoma or chronic end-stage liver disease during their lifetime. This, in turn, is responsible for around 650000 deaths annually worldwide. Repeated hepatitis flares may increase the progression of liver fibrosis, making the accurate diagnosis of the stage of liver fibrosis critical in order to make antiviral therapeutic decisions for HBV-infected patients. Liver biopsy remains the “gold standard” for diagnosing liver fibrosis. However, this technique has recently been challenged by the development of several novel noninvasive tests to evaluate liver fibrosis, including serum markers, combined models and imaging techniques. In addition, the cost and accessibility of imaging techniques have been suggested as additional limitations for invasive assessment of liver fibrosis in developing countries. Therefore, a noninvasive assessment model has been suggested to evaluate liver fibrosis, specifically in HBV-infected patients, owing to its high applicability, inter-laboratory reproducibility, wide availability for repeated assays and reasonable cost. The current review aims to present the status of knowledge in this new and exciting field, and to highlight the key points in HBV-infected patients for clinicians.

A comparison of multimodal biomarkers for chronic hepatitis B assessment using recursive feature elimination

An effective assessment of liver fibrosis in patients with chronic hepatitis B (CHB) is highly desired because it is important not only for clinical courses prediction, but also for the determination of antiviral therapy schemes. In recent years, various approaches for liver biopsies analysis have been highlighted, such as elastography techniques and serum markers, due to their properties of non-invasiveness. The aim of this study is to determine the best biomarkers or their combination by comparing multimodal biomarkers (ultrasound elastography parameters, biochemical hematologic parameters, and clinical parameters) for fibrosis assessment in chronic hepatitis B using a support vector machine combined with recursive feature elimination (RFE-SVM) approach. Results revealed that biomarkers from ultrasound elastography techniques achieved better prediction performance than others in the assessment of significant fibrosis (≥ F2) and cirrhosis (F4), and the best prediction performance were (1) ≥ F2: AUC = 0.902, ACC = 86.697%; (2) F4: AUC = 0.976, ACC = 90.364%. The findings are useful in guiding biomarkers selection and features optimization and in simplifying the prediction system for evaluation of liver fibrosis stage.

Transient elastography in clinical detection of liver cirrhosis: A systematic review and meta-analysis

BACKGROUND/AIMS

Transient elastography is a noninvasive method for measuring liver fibrosis. This meta-analysis assesses the diagnostic performance of transient elastography of detecting liver cirrhosis in patients with liver disease.

PATIENTS AND METHODS

We searched MEDLINE, Cochrane, EMBASE databases until Jan 31, 2015, using the following search terms: elastography and liver cirrhosis. Included studies assessed patients with a diagnosis of liver cirrhosis, with an index test of transient elastography, and with the reference standard being a histopathological exam by liver biopsy. Sensitivity analysis and assessment of risk of bias and publication bias were performed.

RESULTS

Fifty-seven studies were included in the meta-analysis with a total of 10,504 patients. The pooled estimate for the sensitivity of transient elastography for detecting liver fibrosis was 81% and the specificity was 88%. The imputed diagnostic odds ratio (DOR) was 26.08 and the area under the receiver-operating characteristic (AUROC) curve was 0.931.

CONCLUSION

Our findings indicate that transient elastography shows good sensitivity, specificity and a high accuracy for detecting liver cirrhosis. Transient elastography can be used as an additional method for the clinical diagnosis of liver fibrosis and cirrhosis.

Liver Shear-Wave Velocity and Serum Fibrosis Markers to Diagnose Hepatic Fibrosis in Patients with Chronic Viral Hepatitis B

Objective

To compare several noninvasive indices of fibrosis in chronic viral hepatitis B, including liver shear-wave velocity (SWV), hyaluronic acid (HA), collagen type IV (CIV), procollagen type III (PCIII), and laminin (LN).

Materials and Methods

Acoustic radiation force impulse (ARFI) was performed in 157 patients with chronic viral hepatitis B and in 30 healthy volunteers to measure hepatic SWV (m/s) in a prospective study. Serum markers were acquired on the morning of the same day of the ARFI evaluation. Receiver operating characteristic (ROC) analysis was performed to evaluate and compare the accuracies of SWV and serum markers using METAVIR scoring from liver biopsy as a reference standard.

Results

The most accurate test for diagnosing fibrosis F ≥ 1 was SWV with the area under the ROC curve (AUC) of 0.913, followed by LN (0.744), HA (0.701), CIV (0.690), and PCIII (0.524). The best test for diagnosing F ≥ 2 was SWV (AUC of 0.851), followed by CIV (0.671), HA (0.668), LN (0.562), and PCIII (0.550). The best test for diagnosing F ≥ 3 was SWV (0.854), followed by CIV (0.693), HA (0.675), PCIII (0.591), and LN (0.548). The best test for diagnosing F = 4 was SWV (0.965), followed by CIV (0.804), PCIII (0.752), HA (0.744), and LN (0.662). SWV combined with HA and CIV did not improve diagnostic accuracy (AUC = 0.931 for F ≥ 1, 0.863 for F ≥ 2, 0.855 for F ≥ 3, 0.960 for F = 4).

Conclusion

The performance of SWV in diagnosing liver fibrosis is superior to that of serum markers. However, the combination of SWV, HA, and CIV does not increase the accuracy of diagnosing liver fibrosis and cirrhosis.

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

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

Contemporary use of elastography in liver fibrosis and portal hypertension

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

The prognostic values of 12 cirrhosis-relative noninvasive models in patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinogenesis is associated with the progression of cirrhosis, and the latter further aggravates tumor development and prognosis. The aim of the study was to investigate the prognostic values of 12 cirrhosis-relative noninvasive models in hepatocellular carcinoma (HCC).

METHODS

We retrospectively analyzed 363 HCC patients who either underwent partial hepatectomy (PH) or received transcatheter arterial chemoembolization (TCAE). Preoperative data were collected to calculate these indices using the original formulas. Diagnostic accuracy of these models in detection of cirrhosis was evaluated by area under receiver operating characteristic curve (AUC) analysis. Multivariate analyses were performed to assess the independent prognostic significance of the 12 indicators.

RESULTS

Aspartate aminotransferase-platelet ratio index (APRI) and Goteborg University Cirrhosis Index (GUCI) were found to be significant in discriminating cirrhotic patients from non-cirrhotic individuals. When the indices were expressed as continuous variables, multivariate analyses indicated that APRI and GUCI were independent indices to predict overall survival in patients underwent PH, with a hazard ratio (HR) value 1.04 (p = 0.005) and 1.07 (p = 0.001), respectively. In the cohort of TACE, APRI and GUCI were independently associated with survival as well.

CONCLUSION

Of the 12 indices, APRI and GUCI were relatively accurate predictors of cirrhosis status as well as outcome of HCC. As only a limited study population was enrolled in the current study, larger cohorts are needed to validate our results.