Acoustic radiation force impulse elastography, FibroScan®, Forns' index and their combination in the assessment of liver fibrosis in patients with chronic hepatitis B, and the impact of inflammatory activity and steatosis on these diagnostic methods

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.

Novel index for the prediction of significant liver fibrosis and cirrhosis in chronic hepatitis B patients in China

BACKGROUND

Noninvasive, practical, and convenient means of detection for the prediction of liver fibrosis and cirrhosis in China are greatly needed.

AIM

To develop a precise noninvasive test to stage liver fibrosis and cirrhosis.

METHODS

With liver biopsy as the gold standard, we established a new index, [alkaline phosphatase (U/L) + gamma-glutamyl transpeptidase (U/L)/platelet (10⁹/L) (AGPR)], to predict liver fibrosis and cirrhosis. In addition, we compared the area under the receiver operating characteristic curve (AUROC) of AGPR, gamma-glutamyl transpeptidase to platelet ratio, aspartate transaminase to platelet ratio index, and FIB-4 and evaluated the accuracy of these routine laboratory indices in predicting liver fibrosis and cirrhosis.

RESULTS

Correlation analysis revealed a significant positive correlation between AGPR and liver fibrosis stage (P < 0.001). In the training cohort, the AUROC of AGPR was 0.83 (95%CI: 0.78-0.87) for predicting fibrosis (≥ F2), 0.84 (95%CI: 0.79-0.88) for predicting extensive fibrosis (≥ F3), and 0.87 (95%CI: 0.83-0.91) for predicting cirrhosis (F4). In the validation cohort, the AUROCs of AGPR to predict ≥ F2, ≥ F3 and F4 were 0.83 (95%CI: 0.77-0.88), 0.83 (95%CI: 0.77-0.89), and 0.84 (95%CI: 0.78-0.89), respectively.

CONCLUSION

The AGPR index should become a new, simple, accurate, and noninvasive marker to predict liver fibrosis and cirrhosis in chronic hepatitis B patients.

Ultrasound score combined with liver stiffness measurement by sound touch elastography for staging liver fibrosis in patients with chronic hepatitis B: a clinical prospective study

Background

A noninvasive and precise diagnosis of liver fibrosis in patients with chronic hepatitis B (CHB) is crucial for establishing the optimal time and strategy of therapy and for predicting treatment response. This study aimed to assess the diagnostic performance of ultrasound (US) score and liver stiffness measurement (LSM) of sound touch elastography (STE) in diagnosing liver fibrosis stages and to investigate whether combining these methods would improve liver fibrosis staging.

Methods

US and STE examinations were performed in CHB patients included. Liver biopsy was used as a reference standard. A diagnostic marker with the optimal linear combination (LC) of US score and LSM of STE, namely LC marker, was established for noninvasive assessment of liver fibrosis stages. The diagnostic performance of the LC marker was evaluated by using receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC).

Results

A total of 291 subjects, including 242 patients with CHB and 49 healthy volunteers, were included. Correlation analysis showed that the correlation of liver fibrosis stages to the LC marker (Spearman's r=0.846, P<0.001) was higher than that of LSM (r=0.771, P<0.001) or US score (r=0.825, P<0.001) alone. The results showed that the overall diagnostic performance of the LC marker in predicting a fibrosis stage of ≥F1, ≥F2, ≥F3, and =F4 {AUCs: 0.943 [95% confidence interval (CI): 0.917-0.948], 0.906 (0.871-0.915), 0.953 (0.923-0.969), and 0.961 (0.922-0.973), respectively} were better than those of the US score [AUCs: 0.916 (0.883-0.948, P=0.014), 0.875 (0.835-0.915, P<0.001), 0.934 (0.898-0.969, P=0.001), and 0.918 (0.864-0.973, P<0.001), respectively] or LSM [AUCs: 0.858 (0.812-0.948, P<0.001), 0.867 (0.826-0.915, P=0.006), 0.930 (0.894-0.969, P<0.023), and 0.958 (0.918-0.973, P=0.778), respectively].

Conclusions

The LC marker with the optimal combination of LSM and US score may be considered as a promising diagnostic model for noninvasive staging of liver fibrosis.

Quantitative ultrasound, elastography, and machine learning for assessment of steatosis, inflammation, and fibrosis in chronic liver disease

Objective

To develop a quantitative ultrasound (QUS)- and elastography-based model to improve classification of steatosis grade, inflammation grade, and fibrosis stage in patients with chronic liver disease in comparison with shear wave elastography alone, using histopathology as the reference standard.

Methods

This ancillary study to a prospective institutional review-board approved study included 82 patients with non-alcoholic fatty liver disease, chronic hepatitis B or C virus, or autoimmune hepatitis. Elastography measurements, homodyned K-distribution parametric maps, and total attenuation coefficient slope were recorded. Random forests classification and bootstrapping were used to identify combinations of parameters that provided the highest diagnostic accuracy. Receiver operating characteristic (ROC) curves were computed.

Results

For classification of steatosis grade S0 vs. S1-3, S0-1 vs. S2-3, S0-2 vs. S3, area under the receiver operating characteristic curve (AUC) were respectively 0.60, 0.63, and 0.62 with elasticity alone, and 0.90, 0.81, and 0.78 with the best tested model combining QUS and elastography features. For classification of inflammation grade A0 vs. A1-3, A0-1 vs. A2-3, A0-2 vs. A3, AUCs were respectively 0.56, 0.62, and 0.64 with elasticity alone, and 0.75, 0.68, and 0.69 with the best model. For classification of liver fibrosis stage F0 vs. F1-4, F0-1 vs. F2-4, F0-2 vs. F3-4, F0-3 vs. F4, AUCs were respectively 0.66, 0.77, 0.72, and 0.74 with elasticity alone, and 0.72, 0.77, 0.77, and 0.75 with the best model.

Conclusion

Random forest models incorporating QUS and shear wave elastography increased the classification accuracy of liver steatosis, inflammation, and fibrosis when compared to shear wave elastography alone.

Systematic review with meta-analysis: prevalence of hepatic steatosis, fibrosis and associated factors in chronic hepatitis B

BACKGROUND

As the prevalence of hepatitis steatosis (HS) increases, the prevalence of HS among those with chronic hepatitis B (CHB) may also be increasing but data on the effect of HS on CHB disease progression are lacking.

AIMS

To determine the prevalence of HS in CHB and associated factors, prevalence of fibrosis and its association with HS.

METHODS

Two researchers independently searched the literature and extracted data. We included full-length original articles of adults with CHB that evaluated. Prevalence estimates were pooled using a random-effects model. Associations between HS and fibrosis were assessed by pooled odds ratios (ORs) or mean differences (MD).

RESULTS

Of the 2821 records screened, 54 eligible studies (28 648 patients) were analysed. The pooled prevalence of HS in CHB was 32.8% (95% CI, 28.9-37.0) with higher prevalence in men and obese patients. Older age, male sex and metabolic factors were associated with HS while an inverse association was observed between HS and HBeAg (OR 0.82, 95% CI, 0.75-0.91) and HBV DNA levels (MD -0.38, 95% CI -1.16--0.42). The pooled prevalence of significant fibrosis (≥F2 or ≥F3) was similar between patients with CHB with or without HS (40.1% vs 42.22%, P = 0.68). HS was not significantly associated with fibrosis (pooled OR 0.87, 95% CI 0.54-1.39, 20 studies, 6232 patients).

CONCLUSIONS

Approximately 30% of patients with CHB had HS, which was positively associated with male sex, diabetes and metabolic factors, and was negatively associated with HBeAg and HBV DNA. HS was not significantly associated with increased fibrosis.

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.

A noninvasive index to predict liver cirrhosis in biliary atresia

BACKGROUND

Biliary atresia is a progressive obliterative cholangiopathy affecting both extrahepatic and intrahepatic biliary trees, resulting in fibrous obliteration of the biliary tract and subsequent development of cirrhosis.

OBJECTIVE

The aim of this study was to find noninvasive indices to predict the status of hepatic fibrosis in children with biliary atresia.

MATERIALS AND METHODS

We retrospectively measured the volume of the hepatic lobes and spleen from MR images, obtained biochemical data and analyzed the relationship between the imaging and biochemical indices, and the pathological status of hepatic fibrosis in 35 children with biliary atresia.

RESULTS

A combined index was obtained by logistic regression: logit (likelihood of cirrhosis) = 0.00043 x age at MR examination + 1.67 x aspartate aminotransferase and platelet ratio index (APRI) + 0.0029 x body-surface-area-adjusted left liver lobe volume (BSA adLLV) - 6.57 (log-likelihood chi-square P<0.05, pseudo-R²=0.59). The area under the receiver operator characteristic curve of age at MR examination, APRI, BSA adLLV and the combined index for prediction of cirrhosis were 0.91, 0.86, 0.83 and 0.94, respectively. The optimal cut-off value (sensitivity and specificity) of age at MR examination, APRI, BSA adLLV and combined index were 132 (86% and 92%), 1.3 (91% and 85%), 855.5 (96% and 62%) and 0.689 (91% and 92%). The accuracy of age at MR examination, APRI, BSA adLLV and combined index were 89%, 89%, 83% and 91%, respectively.

CONCLUSION

A combined noninvasive index of age, aspartate aminotransferase and platelet ratio index, and the body-surface-area-adjusted left liver lobe volume measured from MR images is a potential marker of liver cirrhosis in children with biliary atresia.

A New Endemic of Concomitant Nonalcoholic Fatty Liver Disease and Chronic Hepatitis B

Hepatitis B virus (HBV) infection remains a global public problem despite the availability of an effective vaccine. In the past decades, nonalcoholic fatty liver disease (NAFLD) has surpassed HBV as the most common cause of chronic liver disease worldwide. The prevalence of concomitant chronic hepatitis B (CHB) and NAFLD thus reaches endemic proportions in geographic regions where both conditions are common. Patients with CHB and NAFLD are at increased risk of liver disease progression to cirrhosis and hepatocellular carcinoma. Due to the complexity of the pathogenesis, accurate diagnosis of NAFLD in CHB patients can be challenging. Liver biopsy is considered the gold standard for diagnosing and determining disease severity, but it is an invasive procedure with potential complications. There is a growing body of literature on the application of novel noninvasive serum biomarkers and advanced radiological modalities to diagnose and evaluate NAFLD, but most have not been adequately validated, especially for patients with CHB. Currently, there is no approved therapy for NAFLD, although many new agents are in different phases of development. This review provides a summary of the epidemiology, clinical features, diagnosis, and management of the NAFLD and highlights the unmet needs in the areas of CHB and NAFLD coexistence.

Preliminary Clinical Experience with Shear Wave Dispersion Imaging for Liver Viscosity in Preoperative Diagnosis of Focal Liver Lesions

BACKGROUND

 The aim of our study is to analyze viscosity characteristics of focal liver lesions (FLLs) and the diagnostic performance of shear wave dispersion (SWD) in differentiating benign and malignant FLLs.

METHODS

 Between January 2018 and April 2018, 58 consecutive patients (median age 57, age range 21-74 years, 37 males) with 58 FLLs located on the right lobe of liver were prospectively studied. The Aplio i900 series diagnostic ultrasound system (Canon Medical systems) equipped with a curvilinear PV1-475BX transducer (1-8 MHz) was used. SWD slope and viscosity measurements were expressed as mean ± standard deviation for both liver tumors and background liver parenchyma. Histopathological results after surgery were regarded as the gold standard for diagnosis.

RESULTS

 Final diagnosis included 40 cases of malignant and 18 cases of benign FLLs. The mean viscosity value were 14.78 ± 1.86 m/s/kHz for hepatocellular carcinoma (n = 30), 14.81 ± 2.35 m/s/kHz for liver metastasis lesions (n = 10), 13.23 ± 1.31 m/s/kHz for hemangioma (n = 13), and 13.67 ± 2.72 m/s/kHz for focal nodular hyperplasia (n = 5). Malignant FLLs showed higher mean viscosity values (14.79 ± 3.15 m/s/KHz) than benign FLLs (13.36 ± 2.76 m/s/KHz) (p < 0.05). The best performing cut-off value of lesion viscosity was 13.15 m/s/kHz (sensitivity 83.3 %; specificity 56.5 %; area under the curve (AUC) 0.71) for malignancy) (p < 0.05).

CONCLUSIONS

 The analysis of SWD slope and liver viscosity parameters provide additional viscoelastic information about FLLs before operation.

Serum ceruloplasmin can predict liver fibrosis in hepatitis B virus-infected patients

BACKGROUND

The presence of significant liver fibrosis in hepatitis B virus (HBV)-infected individuals with persistently normal serum alanine aminotransferase (PNALT) levels is a strong indicator for initiating antiviral therapy. Serum ceruloplasmin (CP) is negatively correlated with liver fibrosis in HBV-infected individuals.

AIM

To examine the potential value of serum CP and develop a noninvasive index including CP to assess significant fibrosis among HBV-infected individuals with PNALT.

METHODS

Two hundred and seventy-five HBV-infected individuals with PNALT were retrospectively evaluated. The association between CP and fibrotic stages was statistically analyzed. A predictive index including CP [Ceruloplasmin hepatitis B virus (CPHBV)] was constructed to predict significant fibrosis and compared to previously reported models.

RESULTS

Serum CP had an inverse correlation with liver fibrosis (r = -0.600). Using CP, the areas under the curves (AUCs) to predict significant fibrosis, advanced fibrosis, and cirrhosis were 0.774, 0.812, and 0.853, respectively. The CPHBV model was developed using CP, platelets (PLT), and HBsAg levels to predict significant fibrosis. The AUCs of this model to predict significant fibrosis, advanced fibrosis, and cirrhosis were 0.842, 0.920, and 0.904, respectively. CPHBV was superior to previous models like the aspartate aminotransferase (AST)-to-PLT ratio index, Fibrosis-4 score, gamma-glutamyl transpeptidase-to-PLT ratio, Forn’s score, and S-index in predicting significant fibrosis in HBV-infected individuals with PNALT.

CONCLUSION

CPHBV could accurately predict liver fibrosis in HBV-infected individuals with PNALT. Therefore, CPHBV can be a valuable tool for antiviral treatment decisions.

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.

The Effects of Hepatic Steatosis on the Natural History of HBV Infection

Fatty liver prevalence is increasing and becoming a global health burden. Chronic hepatitis B infection (CHB) is one of the most common chronic viral infections. Steatosis in CHB patients increases risk of cirrhosis and hepatocellular carcinoma. Data from studies on the interaction between CHB and nonalcoholic fatty liver disease are not conclusive. Liver biopsy is the gold standard for diagnosis of fatty liver; however, noninvasive diagnostic tests have been developed to diagnose and predict fibrosis in CHB/NAFLD. Treatment guidelines are not clear.

Moderate to severe hepatic steatosis leads to overestimation of liver stiffness measurement in chronic hepatitis B patients without significant fibrosis

BACKGROUND

Liver stiffness measurement (LSM) by transient elastography is a noninvasive method for the diagnosis of hepatic fibrosis. The impact of hepatic steatosis on LSM remains to be explored.

AIM

To determine whether LSM is affected by hepatic steatosis in patients with chronic hepatitis B (CHB).

METHODS

Consecutive patients with biopsy-proven CHB were prospectively enrolled. Hepatic steatosis was classified by pathology as none (S0, <5%), mild (S1, 5%-33%), and moderate-severe (S2-3, >33%), and quantitatively by controlled attenuation parameter (CAP) as CAP S0 (≤247 dB/m), CAP S1 (248-267 dB/m) and CAP S2-3 (≥268 dB/m). Liver fibrosis was assessed by METAVIR classification and noninvasively by LSM.

RESULTS

The prevalence of non-alcoholic fatty liver disease (n = 223) in CHB patients (n = 593) was 37.6%. Forty-eight belonged to S2-3 and 127 belonged to CAP S2-3. In patients without significant fibrosis (F0-1), the median LSM (kPa) was 7.4 in S2-3 and 7.1 in CAP S2-3, which was significantly higher than that in S0/S1 (P = 0.005) and CAP S0/S1 (P = 0.003). No significant difference was found in significant fibrosis (F2-4). For LSM identifying significant fibrosis (F2-4), the negative predictive value was higher in CHB patients with CAP ≥ 268 compared to those with CAP < 268 (0.81 vs 0.73); the positive predictive value was lower in CAP ≥ 268 than its counterpart (0.65 vs 0.76).

CONCLUSIONS

Moderate-severe steatosis increased the LSM value in CHB patients without significant fibrosis. A CAP ≥ 268 did not affect LSM for ruling out, but it slightly affected LSM for ruling in significant fibrosis.

TRIAL REGISTRATION

ChiCTR-DDT-13003983.

Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis

BACKGROUND

Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed.

AIM

To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging.

METHODS

This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young's modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination.

RESULTS

2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC > 0.7, P < 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC > 0.7, P < 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P > 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC > 0.7, P < 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P < 0.05), whereas no significant differences were observed in other comparisons (P > 0.05).

CONCLUSION

Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution.

Effects of Hepatic Steatosis on Non-Invasive Liver Fibrosis Measurements Between Hepatitis B and Other Etiologies

Fibrosis-4 (FIB4), transient elastography (TE), and acoustic radiation force impulse (ARFI) are popular modalities to assess liver fibrosis. Their cutoff values for degrees of fibrosis vary between studies. The influence of hepatic steatosis on fibrosis measurements for different etiologies was evaluated. Data from a consecutive series of patients who received fibrosis measurement were included for the training group. An additional series with histology served as the validation group. A standardized protocol was performed for both TE and ARFI, mostly by a single technician. Patients with alcoholism, autoimmune disease, active inflammation, or who were receiving therapy were excluded. The training group included 215 patients and the validation group included 221. The correlation of liver stiffness between TE and ARFI was good (R2 linear = 0.798; p < 0.001). Different correlations between ARFI and TE were noted between high and low control attenuation parameter (CAP) values (cutoff: 290 dB/m), especially in the non-hepatitis B subgroups. Relatively lower FIB4 and TE values were seen in the high CAP versus low CAP in patients with histology-proven non-alcoholic fatty liver disease and chronic hepatitis C. FIB4 cutoff values were >25% lower among F2-F4 stages and the TE cutoff value for F4 was 8.5% lower in the high versus low CAP group. Such findings were not observed in chronic hepatitis B. Different fibrogenesis mechanisms between hepatitis B and non-B are discussed. We conclude that hepatic steatosis significantly impacts FIB4 and TE fibrosis measurements in non-hepatitis B-related liver diseases. Fibrosis grade should be interpreted with caution in severe steatosis.

Viscoelasticity Measurement in Rat Livers Using Shear-Wave US Elastography

To investigate the usefulness of shear-wave speed and dispersion slope measurements obtained, using an ultrasound elastography system in rat livers with various degrees of necroinflammation and fibrosis. A total of 25 male Sprague Dawley rats were randomly divided into 5 groups of 5 rats each: G0 (control), G1 (CCl₄ injected twice a week for 1 wk), G2 (CCl₄ injected four times a wk for 1 wk), G3 (CCl₄ injected twice a wk for 6 wk) and G4 (CCl₄ injected twice a wk for 10 wk). The shear-wave speed (m/s) and the dispersion slope ([m/s]/kHz) were measured. Histologic features (inflammation, necrosis and fibrosis) were used as reference standards. In multivariable analysis with histologic features as independent variables, the fibrosis grade was significantly related to shear-wave speed (p < 0.05) and the necrosis grade was significantly related to dispersion slope (p < 0.05). Dispersion slope is more useful than shear-wave speed for predicting the degree of necroinflammation.

Liver Fibrosis with Two-dimensional US Shear-Wave Elastography in Participants with Chronic Hepatitis B: A Prospective Multicenter Study

Purpose To investigate the diagnostic performance of two-dimensional (2D) shear-wave elastography (SWE) in chronic hepatitis B. Materials and Methods This prospective multicenter study from January 2015 to January 2016 was conducted at 12 hospitals and included 654 participants with chronic hepatitis B who had undergone liver biopsy and 2D SWE examination. Participants were divided into chronic infection and chronic hepatitis groups. The diagnostic performance of 2D SWE was compared with the aspartate amino transferase-to-platelet ratio index (APRI), the Fibrosis-4 index (FIB-4), and transient elastography (TE) by using a DeLong test and was also compared between two subgroups. Dual cutoff values for cirrhosis were determined with multilevel likelihood ratio analysis. Results Overall, 402 participants with chronic hepatitis B were enrolled (154 with chronic infection and 248 with chronic hepatitis). The areas under the receiver operating characteristic curve of 2D SWE (0.87; 95% confidence interval [CI]: 0.83, 0.90) were higher than those of TE (0.80; 95% CI: 0.68, 0.88), APRI (0.70; 95% CI: 0.65, 0.74), and FIB-4 (0.73; 95% CI: 0.69, 0.78) in cirrhosis. The high area under the receiver operating characteristic curve (0.92; 95% CI: 0.87, 0.96) was achieved in the chronic infection group and was significantly higher than that of the chronic hepatitis group (0.84; 95% CI: 0.78, 0.88; P = .017). Dual cutoff values with the likelihood ratios below 0.1 and above 10 (8.4 kPa and 11.0 kPa to rule out and rule in a diagnosis of cirrhosis, respectively) were effectively determined in chronic infection; a total of 81.2% (125 of 154) participants with cirrhosis were definitively diagnosed. Conclusion The performance of two-dimensional (2D) shear-wave elastography (SWE) was higher than that of other noninvasive methods. 2D SWE was most effective in ruling in and ruling out cirrhosis in participants with chronic infection, which may prompt antiviral treatment. © RSNA, 2018 Online supplemental material is available for this article.

Transient Elastography for Significant Liver Fibrosis and Cirrhosis in Chronic Hepatitis B: A Meta-Analysis

BACKGROUND

The hepatitis B virus infection is a global health issue and the stage of liver fibrosis affects the prognosis in patients with chronic hepatitis B (CHB). We performed the meta-analysis describing diagnostic accuracy of transient elastography (TE) for predicting CHB-related fibrosis.

METHODS

We performed an adequate literature search to identify studies that assessed the diagnostic accuracy of TE in CHB patients using biopsy as reference standard. Hierarchical summary receiver-operating curves model and the bivariate mixed-effects binary regression model were applied to generate summary receiver-operating characteristic curves and pooled estimates of sensitivity and specificity.

RESULTS

The area under the summary receiver-operating curve for significant fibrosis and cirrhosis was 0.86 (95% confidence interval (CI): 0.83-0.89) and 0.92 (95% CI: 0.90-0.94), respectively. The sensitivity, specificity, and diagnostic odds ratio of TE for significant fibrosis were 0.78 (95% CI: 0.73-0.81, p < 0.01; I² = 85.59%), 0.81 (95% CI: 0.77-0.84, p < 0.01; I² = 88.20%), and 14.44 (95% CI: 10.80-19.31, p < 0.01; I² = 100%) and for cirrhosis were 0.84 (95% CI: 0.80-0.88, p < 0.01; I² = 76.67%), 0.87 (95% CI: 0.84-0.90, p < 0.01; I² = 90.89%), and 36.63 (95% CI: 25.38-52.87, p < 0.01; I² = 100%), respectively. The optimal cut-off values of TE were 7.25 kPa for diagnosing significant fibrosis and 12.4 kPa for diagnosing cirrhosis, respectively.

CONCLUSION

TE is of great value in the detection of patients with CHB-related cirrhosis but has a suboptimal accuracy in the detection of significant fibrosis.

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.

Acoustic radiation force impulse (ARFI) elastography of the bowel wall as a possible marker of inflammatory activity in patients with Crohn's disease

AIM

To evaluate acoustic radiation force impulse (ARFI) shear-wave velocities of the bowel wall in patients with Crohn's disease (CD).

MATERIAL AND METHODS

ARFI shear-wave elastography was analysed within the wall of the stomach, terminal ileum, and sigmoid, and correlated with ultrasound signs of activity in CD patients both retrospectively and in a prospective cohort.

RESULTS

A total of 77 retrospective and 21 prospective CD patients were included. ARFI elastography in the stomach, the normal ileum, and sigmoid was lower than in ileitis or sigmoiditis. Retrospectively, the ARFI values correlated with the bowel wall thickness and Limberg vascularisation score. Prospectively, there was no correlation between ARFI and bowel wall thickness, Limberg score, clinical activity, or C-reactive protein. A cut-off analysis of 105 ileal ARFI measurements showed a cut-off value of 1.92 m/s for the diagnosis of ileal inflammation with 75.3% sensitivity and 87.5% specificity.

CONCLUSION

In patients with CD, ARFI shear-wave velocities show a trend to higher values in inflamed bowel wall thickening on B-mode ultrasound; however, the differences appear small and may not be clinically significant. The factors influencing ARFI measurements of the bowel wall require further investigation.

A Single Test Combining Blood Markers and Elastography is More Accurate Than Other Fibrosis Tests in the Main Causes of Chronic Liver Diseases

BACKGROUND AND GOAL

International guidelines suggest combining a blood test and liver stiffness measurement (LSM) to stage liver fibrosis in chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD). Therefore, we compared the accuracies of these tests between the main etiologies of chronic liver diseases.

STUDY

Overall, 1968 patients were included in 5 etiologies: CHC: 698, chronic hepatitis B: 152, human immunodeficiency virus/CHC: 628, NAFLD: 225, and alcoholic liver disease (ALD): 265. Sixteen tests [13 blood tests, LSM (Fibroscan), 2 combined: FibroMeters] were evaluated. References were Metavir staging and CHC etiology. Accuracy was evaluated mainly with the Obuchowski index (OI) and accessorily with area under the receiver operating characteristics (F≥2, F≥3, cirrhosis).

RESULTS

OIs in CHC were: FibroMeters: 0.812, FibroMeters: 0.785 to 0.797, Fibrotest: 0.762, CirrhoMeters: 0.756 to 0.771, LSM: 0.754, Hepascore: 0.752, FibroMeter: 0.750, aspartate aminotransferase platelet ratio index: 0.742, Fib-4: 0.741. In other etiologies, most tests had nonsignificant changes in OIs. In NAFLD, CHC-specific tests were more accurate than NAFLD-specific tests. The combined FibroMeters had significantly higher accuracy than their 2 constitutive tests (FibroMeters and LSM) in at least 1 diagnostic target in all etiologies, except in ALD where LSM had the highest OI, and in 3 diagnostic targets (OIs and 2 area under the receiver operating characteristics) in CHC and NAFLD.

CONCLUSIONS

Some tests developed in CHC outperformed other tests in their specific etiologies. Tests combining blood markers and LSM outperformed single tests, validating recent guidelines and extending them to main etiologies. Noninvasive fibrosis evaluation can thus be simplified in the main etiologies by using a unique test: either LSM alone, especially in ALD, or preferably combined to blood markers.

Liver fibrosis diagnosis by blood test and elastography in chronic hepatitis C: agreement or combination?

BACKGROUND

In chronic hepatitis C, the European Association for the Study of the Liver and the Asociacion Latinoamericana para el Estudio del Higado recommend performing transient elastography plus a blood test to diagnose significant fibrosis; test concordance confirms the diagnosis.

AIM

To validate this rule and improve it by combining a blood test, FibroMeter (virus second generation, Echosens, Paris, France) and transient elastography (constitutive tests) into a single combined test, as suggested by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America.

METHODS

A total of 1199 patients were included in an exploratory set (HCV, n = 679) or in two validation sets (HCV ± HIV, HBV, n = 520). Accuracy was mainly evaluated by correct diagnosis rate for severe fibrosis (pathological Metavir F ≥ 3, primary outcome) by classical test scores or a fibrosis classification, reflecting Metavir staging, as a function of test concordance.

RESULTS

Score accuracy: there were no significant differences between the blood test (75.7%), elastography (79.1%) and the combined test (79.4%) (P = 0.066); the score accuracy of each test was significantly (P < 0.001) decreased in discordant vs. concordant tests. Classification accuracy: combined test accuracy (91.7%) was significantly (P < 0.001) increased vs. the blood test (84.1%) and elastography (88.2%); accuracy of each constitutive test was significantly (P < 0.001) decreased in discordant vs. concordant tests but not with combined test: 89.0 vs. 92.7% (P = 0.118). Multivariate analysis for accuracy showed an interaction between concordance and fibrosis level: in the 1% of patients with full classification discordance and severe fibrosis, non-invasive tests were unreliable. The advantage of combined test classification was confirmed in the validation sets.

CONCLUSIONS

The concordance recommendation is validated. A combined test, expressed in classification instead of score, improves this rule and validates the recommendation of a combined test, avoiding 99% of biopsies, and offering precise staging.

Evaluation of APRI and FIB-4 for noninvasive assessment of significant fibrosis and cirrhosis in HBeAg-negative CHB patients with ALT ≤ 2 ULN: A retrospective cohort study

To evaluate the performance of aspartate transaminase-to-platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4) to predict significant fibrosis and cirrhosis in hepatitis B virus e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients with alanine transaminase (ALT) ≤ twice the upper limit of normal (2 ULN).Histologic and laboratory data of 236 HBeAg-negative CHB patients with ALT ≤ 2 ULN were analyzed. Predicted fibrosis stage, based on established scales and cut-offs for APRI and FIB-4, was compared with METAVIR scores obtained from liver biopsy.In this study, the areas under the receiver operating characteristic curves (AUROCs) of APRI were lower than that of FIB-4 (0.62 vs 0.69; P = 0.019) for diagnosing significant fibrosis; however APRI and FIB-4 were comparable for diagnosing cirrhosis (0.77 vs 0.81; P = 0.374). When the cut-off proposed by WHO HBV guideline for APRI (>2.0) was used, no cirrhotic patients were correctly predicted. For FIB-4, the WHO proposed cut-off of 3.25 correctly identified significant fibrosis 83% of the time; but for APRI, the WHO proposed cut-off of 1.5 identified significant fibrosis 56%. In ruling out significant fibrosis, the WHO proposed APRI cut-off of 0.5 had a predictive value of 39%, and the FIB-4 cut-off of 1.45 correctly identified lack of significant fibrosis in 47% of the patients. In this study, based on ROC analysis, the optimal cut-offs were 0.46 and 0.65 for APRI, and 1.05 and 1.29 for FIB-4, for diagnosing significant fibrosis and cirrhosis, respectively. When the new cut-off of APRI (>0.65) was used, 82% of the cirrhotic patients were correctly predicted. In ruling out significant fibrosis, the new APRI cut-off (<0.46) had a predictive value of 80%, and new FIB-4 cut-off (<1.05) correctly identified lack of significant fibrosis in 84% of the patients.The WHO guidelines proposed cut-offs might be higher for HBeAg-negative CHB patients with ALT ≤2 ULN, and might underestimate the proportion of significant fibrosis and cirrhosis. A new set of cut-offs should be used to predict significant fibrosis and cirrhosis in this specific population.

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.

Low Pretreatment Acoustic Radiation Force Impulse Imaging (ARFI) Values Predict Sustained Virological Response in Antiviral Hepatitis C Virus (HCV) Therapy

Background

Non-invasive procedures such as acoustic radiation force impulse imaging (ARFI) shear-wave elastography are currently used for the assessment of liver fibrosis. In the course of chronic hepatitis C, significant liver fibrosis or cirrhosis develops in approximately 25% of patients, which is a negative predictor of antiviral treatment response. Cirrhosis can be prevented by successful virus elimination.

In this prospective study, a pretreatment ARFI cutoff value of 1.5 m/s was evaluated in relation to sustained virological response to anti-HCV therapy.

Material/Methods

In 23 patients with chronic hepatitis C, liver stiffness was examined with ARFI at defined times before and under antiviral triple therapy (peginterferon, ribavirin in combination with a first-generation protease inhibitor, and telaprevir or boceprevir). Patients were stratified into 2 groups based on pretreatment ARFI values (<1.5 m/s and ≥1.5 m/s) for the assessment of virological response.

Results

The liver stiffness at baseline for all patients was 1.57±0.79 m/s (ARFI median ± standard deviation; margin: 0.81 m/s to 3.45 m/s). At week 4 of triple therapy, patients with low pretreatment ARFI values had higher rates of HCV-RNA negativity (69% vs. 43%), reflecting an early rapid virological response (eRVR). Sustained virological response (SVR) was found in 75% (12/16) of patients with an ARFI value <1.5 m/s and only 57% (4/7) of patients with ARFI value ≥1.5 m/s.

Conclusions

Patients with chronic hepatitis C and pretreatment ARFI <1.5 m/s showed earlier virus elimination and better response to treatment.

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.

Acoustic radiation force impulse imaging for assessing liver fibrosis in alcoholic liver disease

AIM: To evaluate the performance of elastography by ultrasound with acoustic radiation force impulse (ARFI) in determining fibrosis stage in patients with alcoholic liver disease (ALD) undergoing alcoholic detoxification in relation to biopsy.

METHODS: Eighty-three patients with ALD undergoing detoxification were prospectively enrolled. Each patient underwent ARFI imaging and a liver biopsy on the same day. Fibrosis was staged according to the METAVIR scoring system. The median of 10 valid ARFI measurements was calculated for each patient.

RESULTS: Sixty-nine males and thirteen females (one patient excluded due to insufficient biopsy size) were assessed with a mean alcohol consumption of 132.4 ± 128.8 standard drinks per week and mean cumulative year duration of 17.6 ± 9.5 years. Sensitivity and specificity were respectively 82.4% (0.70-0.95) and 83.3% (0.73-0.94) (AUROC = 0.87) for F ≥ 2 with a cut-off value of 1.63m/s; 82.4% (0.64-1.00) and 78.5% (0.69-0.89) (AUROC = 0.86) for F ≥ 3 with a cut-off value of 1.84m/s; and 92.3% (0.78-1.00] and 81.6% (0.72-0.90) (AUROC = 0.89) for F = 4 with a cut-off value of 1.94 m/s.

CONCLUSION: ARFI is an accurate, non-invasive and easy method for assessing liver fibrosis in patients with ALD undergoing alcoholic detoxification.

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.

The Gamma-Glutamyl-Transpeptidase to Platelet Ratio Does not Show Advantages than APRI and Fib-4 in Diagnosing Significant Fibrosis and Cirrhosis in Patients With Chronic Hepatitis B: A Retrospective Cohort Study in China

The gamma-glutamyl-transpeptidase to platelet ratio (GPR) is a new liver fibrosis model, which is reported to be more accurate than aspartate transaminase (AST) to platelet ratio index (APRI) and fibrosis index based on the four factors (Fib-4) for diagnosing significant fibrosis and cirrhosis in patients with chronic hepatitis B (CHB) in West Africa. The aim of this study is to assess the diagnostic accuracy of GPR for significant fibrosis and cirrhosis in Chinese CHB patients, and explore whether GPR deserves to be popularized in China. A total of 372 CHB patients who underwent liver biopsies and routine laboratory tests were retrospectively studied. The Scheuer scoring system was adopted as the pathological standard of liver fibrosis. Using liver histology as a gold standard, the diagnostic accuracies of GPR, APRI, and Fib-4 for significant fibrosis and cirrhosis are evaluated and compared by the receiver operating characteristic (ROC) curves and the area under the ROC curves (AUROCs). Of these 372 patients, 176 (47.3%), 129 (34.7%), and 72 (19.4%) were classified as having significant fibrosis (≥ S2), severe fibrosis (≥ S3), and cirrhosis (S4), respectively. The AUROCs of GPR for significant fibrosis (0.72 vs. 0.78; P = 0.01), severe fibrosis (0.75 vs. 0.80; P = 0.04), and cirrhosis (0.78 vs. 0.83; P = 0.02) were lower than those of APRI. The AUROCs of GPR and Fib-4 for diagnosing significant fibrosis (0.72 vs. 0.70; P = 0.29), severe fibrosis (0.75 vs. 0.73; P = 0.33), and cirrhosis (0.78 vs. 0.75; P = 0.38) were comparable. GPR is a new serum diagnostic model for liver fibrosis and cirrhosis, but does not show advantages than APRI and Fib-4 in identifying significant fibrosis, severe fibrosis, and cirrhosis in CHB patients in China.