Factors of accuracy of transient elastography (fibroscan) for the diagnosis of liver fibrosis in chronic hepatitis C

Diagnosis of cirrhosis and portal hypertension: imaging, non-invasive markers of fibrosis and liver biopsy

The concept of ‘cirrhosis’ is evolving and it is now clear that compensated and decompensated cirrhosis are completely different in terms of prognosis. Furthermore, the term ‘advanced chronic liver disease (ACLD)’ better reflects the continuum of histological changes occurring in the liver, which continue to progress even after cirrhosis has developed, and might regress after removing the etiological factor causing the liver disease. In compensated ACLD, portal hypertension marks the progression to a stage with higher risk of clinical complication and requires an appropriate evaluation and treatment. Invasive tests to diagnose cirrhosis (liver biopsy) and portal hypertension (hepatic venous pressure gradient measurement and endoscopy) remain of crucial importance in several difficult clinical scenarios, but their need can be reduced by using different non-invasive tests in standard cases. Among non-invasive tests, the accepted use, major limitations and major benefits of serum markers of fibrosis, elastography and imaging methods are summarized in the present review.

Factors Influencing the Diagnostic Accuracy of Acoustic Radiation Force Impulse Elastography in Patients with Chronic Hepatitis B

Background/Aims

To determine factors predictive of discordance in staging liver fibrosis using liver biopsy (LB) and acoustic radiation force impulse (ARFI) elastography in patients with chronic hepatitis B (CHB).

Methods

Consecutive patients with CHB who underwent LB and ARFI elastography on the same day from November 2010 to March 2013 were prospectively recruited from three tertiary hospitals.

Results

We analyzed 105 patients (median age of 47 years). The F0–1, F2, F3, and F4 fibrosis stages were identified in 27 (25.7%), 27 (25.7%), 21 (20.0%), and 30 (28.6%) patients, respectively. The areas under the receiver operating characteristics curves for ARFI elastography in assessing ≥F2, ≥F3, and F4 was 0.814, 0.848, and 0.752, respectively. The discordance of at least one stage between LB and ARFI was observed in 68 patients (64.8%) and of at least two stages in 16 patients (15.2%). In a multivariate analysis, advanced fibrosis stage (F3–4) was the only factor that was negatively correlated with one-stage discordance (p=0.042). Moreover, advanced fibrosis stage was negatively (p=0.016) correlated and body mass index (BMI) was positively (p=0.006) correlated with two-stage discordance.

Conclusions

Advanced fibrosis stage (F3–4) was a predictor of nondiscordance between LB and ARFI elastography; BMI also influenced the accuracy of ARFI elastography.

Development of algorithms based on serum markers and transient elastography for detecting significant fibrosis and cirrhosis in chronic hepatitis B patients: Significant reduction in liver biopsy

AIM

To develop algorithms for detecting significant fibrosis and cirrhosis in chronic hepatitis B (CHB) patients with the aim of reducing unwarranted liver biopsy.

METHODS

For 307 CHB patients, the aspartate aminotransferase-to-platelet ratio index (APRI), the fibrosis index based on four factors (FIB-4), and the result of transient elastography with FibroScan (FS) were obtained when a liver biopsy was carried out. All patients were classified based on APRI or FIB-4 score and further assessed by FS results. Patients who remained unclassified after two steps of evaluation were considered to need liver biopsy.

RESULTS

Algorithm implementation found that APRI + FS significantly lowered the requirement for liver biopsy for the detection of significant fibrosis compared to either individual APRI or FS screening (65.1% vs 75.9% or 78.5%, P = 0.003 or <0.001, respectively). The combination of FIB-4 + FS significantly reduced the need for liver biopsy compared to single FIB-4 or FS (58.3% vs 67.4% or 78.5%, P = 0.019 or <0.001, respectively). The FIB-4 + FS algorithm also reduced the need for liver biopsy for detection of significant fibrosis in patients ≥50 years old compared to APRI + FS (22.6% vs 56.5%, P < 0.001), with a relatively lower accuracy (83.9% vs 98.4%, P = 0.004). Only 3.6% or 1.3% of patients needed liver biopsy for diagnosis of cirrhosis after screening with APRI + FS or FIB-4 + FS, respectively.

CONCLUSION

The APRI + FS and FIB-4 + FS algorithms could significantly reduce the need for liver biopsy with high accuracy, sensitivity, and positive predictive value for diagnosis of significant fibrosis and cirrhosis in CHB patients.

Prospective Assessment of Correlation between US Acoustic Radiation Force Impulse and MR Elastography in a Pediatric Population: Dispersion of US Shear-Wave Speed Measurement Matters

Purpose To evaluate the correlation between ultrasonographic (US) point shear-wave elastography (SWE) and magnetic resonance (MR) elastography liver shear-wave speed (SWS) measurements in a pediatric population and to determine if US data dispersion affects this relationship. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant investigation; informed consent and patient assent (as indicated) were obtained. Patients (age range, 0-21 years) undergoing clinical liver MR elastography between July 2014 and November 2015 were prospectively enrolled. Patients underwent two-dimensional gradient-recalled-echo 1.5-T MR elastography with point SWE performed immediately before or immediately after MR elastography. Spearman rank correlation coefficients were calculated to assess the relationship and agreement between point SWE and MR elastography SWS measurements. Uni- and multivariate logistic regression were performed to identify predictors of US data dispersion, with the best multivariate model selected based on Akaike information criterion. Results A total of 55 patients (24 female) were enrolled (mean age, 14.0 years ± 3.9 (standard deviation) (range, 3.5-21.4 years). There was fair correlation between point SWE and MR elastography SWS values for all patients (ρ = 0.33, P = .016). Correlation was substantial, however, when including only patients with minimal US data dispersion (n = 26, ρ = 0.61, P = .001). Mean body mass index (BMI) was significantly lower in patients with minimal US data dispersion than in those with substantial US data dispersion (25.4 kg/m2 ± 7.8 vs 32.3 kg/m2 ± 8.3, P = .003). At univariate analysis, BMI (odds ratio, 1.12; 95% confidence interval [CI]: 1.03, 1.21; P = .006) and abdominal wall thickness (odds ratio, 2.50; 95% CI: 1.32, 4.74; P = .005) were significant predictors of US data dispersion. In the best multivariate model, BMI was the only significant predictor (odds ratio, 1.11; 95% CI: 1.03, 1.20; P = .009). Conclusion Point SWE and MR elastography liver SWS measurements correlate well in patients with a BMI of less than 30 kg/m2 and minimal US data dispersion; increasing US data dispersion is directly related to a higher BMI. © RSNA, 2016.

Transient Elastography with Serum Hepatitis B Surface Antigen Enhances Liver Fibrosis Detection

BACKGROUND The aim of this study was to explore transient elastography (TE) with quantitative hepatitis B surface antigen (qHBsAg) for detecting advanced hepatic fibrosis. MATERIAL AND METHODS This was a single-center prospective real-life analysis of 111 treatment-naïve chronic hepatitis B (CHB) patients enrolled into the Establishment of Non-invasive Diagnosis Criteria and Model of Hepatitis B Virus-related Cirrhosis Study. RESULTS There were significant correlations between TE, qHBsAg, and fibrosis. Both qHBsAg and TE were identified as independent predictors for advanced fibrosis. In receiver operating characteristic curve (ROC) analysis, TEqHBsAg (combination of TE and qHBsAg) resulted in the highest area under the receiver-operator curve (AUC) (0.912), mainly due to increased specificity. Using the optimal cut-off, TEqHBsAg provided a sensitivity of 86.7%, and increased specificity from 78.7% to 85.1%. CONCLUSIONS Combining TE with qHBsAg enhances specificity in identifying advanced fibrosis in treatment-naïve CHB patients.

Comparison of the effect of region-of-interest methods using gadoxetic acid-enhanced MR imaging with diffusion-weighted imaging on staging hepatic fibrosis

OBJECTIVE

To evaluate the utility of T1 mapping on gadoxetic acid-enhanced MRI and DWI for staging liver fibrosis and assess the influence of ROI positioning on interobserver variability, T1 relaxation time and ADC value.

METHODS

This retrospective study was approved by the institutional review board and included 150 patients (mean age 58 years old; 91 men and 59 women). Liver fibrosis stages (S) were histopathologically determined. T1 relaxation time and ADC value of liver were measured by three distinct ROI protocols (the whole left lobe liver, the whole right lobe liver and the individual ROIs). T1 relaxation time measurements were compared with ADC values according to S scores. Interobserver variability for the T1 relaxation times and ADC values by the three distinct ROI protocols was analyzed by calculating the ICC.

RESULTS

T1 relaxation time measurements by the three distinct ROI protocols on severe fibrosis stage were significantly higher than the relative values on mild fibrosis stage. The mean ADC values on severe fibrosis stage showed no significantly different when measured by means of the whole right lobe liver (p = 0.057) and the individual ROIs (p = 0.10), compared with the relative values on mild fibrosis stage. AUCs of T1 relaxation time and ADC value by the means of the three distinct ROI protocols were 0.614, 0.676, 0.677 and 0.656, 0.585, 0.575 for identification of severe fibrosis stage. The interobserver reproducibility was excellent for measuring the right lobe liver T1 relaxation time and the individual ROIs T1 relaxation time (ICC 0.814, 0.883, respectively).

CONCLUSIONS

T1 relaxation time measurements by means of the three distinct ROI protocols on gadoxetic acid-enhanced MR imaging were a potential biomarker in staging of hepatic fibrosis, which were more accuracy than DWI-ADC measurements. The more reproducible results were obtained when measuring T1 relaxation time of the whole right lobe liver and the individual ROIs.

Diagnosis of Clinically Significant Portal Hypertension in Patients with Cirrhosis: Splenic Arterial Resistive Index versus Liver Stiffness Measurement

The purpose of the present study is to compare the diagnostic accuracy of the splenic arterial resistive index (SARI) with that of liver stiffness measurement (LSM) for identifying patients with clinically significant portal hypertension (CSPH). We included 47 patients (M:F = 37:10) who underwent Doppler ultrasonography, LSM and hepatic venous pressure gradient (HVPG) on the same day. We investigated whether the SARI and LSM were correlated with the HVPG, and compared area under the curve (AUC) values for the abilities of SARI and LSM to diagnose CSPH. We also performed a sub-group analysis. The SARI and LSM were all moderately correlated with HVPG overall in patients. The AUC of SARI and LSM were 0.873 and 0.745, respectively. In patients without splenomegaly, SARI was strongly correlated with HVPG (r = 0.830), but LSM was moderately correlated with HVPG (r = 0.601). The AUC was also higher for SARI than for LSM. Therefore, SARI is potentially an excellent non-invasive measurement method for diagnosing CSPH, especially those without splenomegaly.

T2 relaxation time is related to liver fibrosis severity

BACKGROUND

The grading of liver fibrosis relies on liver biopsy. Imaging techniques, including elastography and relaxometric, techniques have had varying success in diagnosing moderate fibrosis. The goal of this study was to determine if there is a relationship between the T2-relaxation time of hepatic parenchyma and the histologic grade of liver fibrosis in patients with hepatitis C undergoing both routine, liver MRI and liver biopsy, and to validate our methodology with phantoms and in a rat model of liver fibrosis.

METHODS

This study is composed of three parts: (I) 123 patients who underwent both routine, clinical liver MRI and biopsy within a 6-month period, between July 1999 and January 2010 were enrolled in a retrospective study. MR imaging was performed at 1.5 T using dual-echo turbo-spin echo equivalent pulse sequence. T2 relaxation time of liver parenchyma in patients was calculated by mono-exponential fit of a region of interest (ROI) within the right lobe correlating to histopathologic grading (Ishak 0-6) and routine serum liver inflammation [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)]. Statistical comparison was performed using ordinary logistic and ordinal logistic regression and ANOVA comparing T2 to Ishak fibrosis without and using AST and ALT as covariates; (II) a phantom was prepared using serial dilutions of dextran coated magnetic iron oxide nanoparticles. T2 weighed imaging was performed by comparing a dual echo fast spin echo sequence to a Carr-Purcell-Meigboom-Gill (CPMG) multi-echo sequence at 1.5 T. Statistical comparison was performed using a paired t-test; (III) male Wistar rats receiving weekly intraperitoneal injections of phosphate buffer solution (PBS) control (n=4 rats); diethylnitrosamine (DEN) for either 5 (n=5 rats) or 8 weeks (n=4 rats) were MR imaged on a Bruker Pharmascan 4.7 T magnet with a home-built bird-cage coil. T2 was quantified by using a mono-exponential fitting algorithm on multi-slice multi echo T2 weighted data. Statistical comparison was performed using ANOVA.

RESULTS

(I) Histopathologic evaluation of both rat and human livers demonstrated no evidence of steatosis or hemochromatosis There was a monotonic increase in mean T2 value with increasing degree of fibrosis (control 65.4±2.9 ms, n=6 patients); mild (Ishak 1-2) 66.7±1.9 ms (n=30); moderate (Ishak 3-4) 71.6±1.7 ms (n=26); severe (Ishak 5-6) 72.4±1.4 ms (n=61); with relatively low standard error (~2.9 ms). There was a statistically significant difference between degrees of mild (Ishak <4) vs. moderate to severe fibrosis (Ishak >4) (P=0.03) based on logistic regression of T2 and Ishak, which became insignificant (P=0.07) when using inflammatory markers as covariates. Expanding on this model using ordinal logistic regression, there was significance amongst all 4 groups comparing T2 to Ishak (P=0.01), with significance using inflammation as a covariate (P=0.03) and approaching statistical significance amongst all groups by ANOVA (P=0.07); (II) there was a monotonic increase in T2 and statistical significance (ANOVA P<0.0001) between each rat subgroup [phosphate buffer solution (PBS) 25.2±0.8, DEN 5-week (31.1±1.5), and DEN 9-week (49.4±0.4) ms]; (III) the phantoms that had T2 values within the relevant range for the human liver (e.g., 20-100 ms), demonstrated no statistical difference between two point fits on turbo spin echo (TSE) data and multi-echo CPMG data (P=0.9).

CONCLUSIONS

The finding of increased T2 with liver fibrosis may relate to inflammation that may be an alternative or adjunct to other noninvasive MR imaging based approaches for assessing liver fibrosis.

Prospective comparison of magnetic resonance imaging to transient elastography and serum markers for liver fibrosis detection

BACKGROUND & AIMS

Establishing accurate non-invasive methods of liver fibrosis quantification remains a major unmet need. Here, we assessed the diagnostic value of a multiparametric magnetic resonance imaging (MRI) protocol including diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE)-MRI and magnetic resonance elastography (MRE) in comparison with transient elastography (TE) and blood tests [including ELF (Enhanced Liver Fibrosis) and APRI] for liver fibrosis detection.

METHODS

In this single centre cross-sectional study, we prospectively enrolled 60 subjects with liver disease who underwent multiparametric MRI (DWI, DCE-MRI and MRE), TE and blood tests. Correlation was assessed between non-invasive modalities and histopathologic findings including stage, grade and collagen content, while accounting for covariates such as age, sex, BMI, HCV status and MRI-derived fat and iron content. ROC curve analysis evaluated the performance of each technique for detection of moderate-to-advanced liver fibrosis (F2-F4) and advanced fibrosis (F3-F4).

RESULTS

Magnetic resonance elastography provided the strongest correlation with fibrosis stage (r = 0.66, P < 0.001), inflammation grade (r = 0.52, P < 0.001) and collagen content (r = 0.53, P = 0.036). For detection of moderate-to-advanced fibrosis (F2-F4), AUCs were 0.78, 0.82, 0.72, 0.79, 0.71 for MRE, TE, DCE-MRI, DWI and APRI, respectively. For detection of advanced fibrosis (F3-F4), AUCs were 0.94, 0.77, 0.79, 0.79 and 0.70, respectively.

CONCLUSIONS

Magnetic resonance elastography provides the highest correlation with histopathologic markers and yields high diagnostic performance for detection of advanced liver fibrosis and cirrhosis, compared to DWI, DCE-MRI, TE and serum markers.

Quantification of liver fibrosis via second harmonic imaging of the Glisson's capsule from liver surface

Liver surface is covered by a collagenous layer called the Glisson's capsule. The structure of the Glisson's capsule is barely seen in the biopsy samples for histology assessment, thus the changes of the collagen network from the Glisson's capsule during the liver disease progression are not well studied. In this report, we investigated whether non-linear optical imaging of the Glisson's capsule at liver surface would yield sufficient information to allow quantitative staging of liver fibrosis. In contrast to conventional tissue sections whereby tissues are cut perpendicular to the liver surface and interior information from the liver biopsy samples were used, we have established a capsule index based on significant parameters extracted from the second harmonic generation (SHG) microscopy images of capsule collagen from anterior surface of rat livers. Thioacetamide (TAA) induced liver fibrosis animal models was used in this study. The capsule index is capable of differentiating different fibrosis stages, with area under receiver operating characteristics curve (AUC) up to 0.91, making it possible to quantitatively stage liver fibrosis via liver surface imaging potentially with endomicroscopy.

Clinical applications, limitations and future role of transient elastography in the management of liver disease

Transient elastography (TE) is a reliable tool for the non-invasive assessment of liver fibrosis in routine clinical practice. TE is currently approved for use in Europe, Asia and the United States. The widespread adoption of this technology is certain to increase the use of TE worldwide. Although TE has been well validated in chronic viral hepatitis, its clinical role in other liver diseases remains less clear. The advent of new treatment for chronic hepatitis C and emerging prevalence of non-alcoholic steatohepatitis raises new questions on the role of TE in current clinical practice. This review aims to examine the clinical applications, limitations and future role of TE in current clinical practice in light of the changing epidemiology of liver diseases and new clinical management paradigms. In current clinical practice, TE is the most accurate non-invasive method for diagnosis of liver cirrhosis. TE is useful to rule out fibrosis and cirrhosis but does not have sufficient accuracy to discern between various stages of fibrosis. The clinical role of TE has evolved from cross-sectional point-in-time assessment of fibrosis and cirrhosis to the more relevant role of prediction of vital clinical end-points. This provides clinicians with the ability to modify treatment strategies based on the information provided by TE. TE has evolved over the past decade to become an essential tool to assist the clinician in the management of chronic liver disease.

Early diagnosis of liver cancer: an appraisal of international recommendations and future perspectives

All Societies, AASLD, EASL, APASL and JSH, identify patients with cirrhosis as a target population for surveillance, with minor differences for additional categories of patients, such as chronic hepatitis B and hepatitis C patients with advanced fibrosis. According to AASLD, liver disease related to metabolic diseases including diabetes and obesity is a recognized target of screening, since those conditions have been causally related to HCC. All societies endorse radiological non-invasive techniques as the mainstay for early diagnosis of HCC, but discrepancies exist between Societies on the utilization of contrast-enhanced ultrasound and utilization of serum markers for surveillance and diagnosis of HCC. The diagnostic algorithm of the international societies differ substantially in the anatomic paradigm of EASL and APASL which identify 1 cm size as the starting point for radiological diagnosis of HCC compared to APASL algorithm based on the dynamic pattern of contrast imaging, independently on tumour size. While strengthening prediction in individual patients is expected to improve cost-effectiveness ratios of screening, the benefits of pre-treatment patient stratification by clinical, histological and genetic scores remain uncertain and exclusion of patients with severe co-morbidities and advanced age is still debated.

Noninvasive assessment of alcoholic liver disease using unidimensional transient elastography (Fibroscan®)

Unidimensional transient elastography (TE) is a noninvasive technique, which has been increasingly used in the assessment of diffuse liver diseases. This paper focuses on reviewing the existing data on the use of TE in the diagnosis of fibrosis and in monitoring disease progression in alcoholic liver disease, on the factors that may influence the result of fibrosis prediction, and last but not least, on its potential use in assessing the steatosis degree. Therefore, this field is far from being exhausted and deserves more attention. Further studies are required, on large groups of biopsied patients, in order to find answers to all the remaining questions in this field.

Management before hepatectomy for hepatocellular carcinoma with cirrhosis

The global distribution of hepatocellular carcinoma (HCC) varies markedly among regions, and patients in East Asia and Central Africa account for about 80% of all cases. The risk factors are hepatitis B, hepatitis C, alcohol, and etc. The risk of carcinogenesis further increases with progression to hepatic cirrhosis in all liver disorders. Radical treatment of HCC by liver resection without causing liver failure has been established as a safe approach through selection of an appropriate range of resection of the damaged liver. This background indicates that both evaluation of hepatic functional reserve and measures against concomitant diseases such as thrombocytopenia accompanying portal hypertension, prevention of rupture of esophageal varices, reliable control of ascites, and improvement of hypoalbuminemia are important issues in liver resection in patients with hepatic cirrhosis. We review the latest information on perioperative management of liver resection in HCC patients with hepatic cirrhosis.

Transient elastography of the liver in children with Wilson's disease: Preliminary results

PURPOSE

In chronic liver diseases, liver stiffness (LS) is increased, primarily because of liver fibrosis, but other factors, such as intrahepatic deposits, may also be involved. We hypothesized that intrahepatic copper accumulation occurring in Wilson's disease (WD) also leads to an increase in LS. The aim of this study was thus to investigate the changes in LS during treatment in pediatric patients with WD.

METHODS

Consecutive patients younger than 18 years old, whose WD was diagnosed between 2008 and 2013, were enrolled. All patients underwent testing for liver function and urinary copper excretion, and LS was measured on transient elastography at baseline and at 6- to 12-month intervals during specific therapy.

RESULTS

Nine patients were included in the analysis; only two were diagnosed with cirrhosis. The median LS decreased during treatment from 15.1 kPa (range, 5.1-66 kPa) at baseline to 10 kPa (4-16.1 kPa) at follow-up interval 1, and to 6.1 kPa (3.9-11.6 kPa) at follow-up interval 2 (p < 0.0001). In parallel, the differences in urinary copper excretion over the follow-up period were not statistically significant, although the decrease in LS correlated with the increase in urinary copper excretion (r = 0.6).

CONCLUSIONS

In pediatric patients with WD, LS is high at the time of diagnosis and decreases during specific treatment, in parallel with an increase in the urinary copper concentration.

Usefulness of indirect noninvasive methods in predicting progression to cirrhosis in chronic hepatitis C

BACKGROUND AND AIMS

The ability of noninvasive methods to predict the development of cirrhosis has not been established. We evaluated the ability of three noninvasive methods [the Forns index, the aspartate aminotransferase-to-platelet ratio index (APRI), and the Non-Invasive Hepatitis-C-related Cirrhosis Early Detection (NIHCED) score] to determine the risk of developing cirrhosis in chronic hepatitis C.

METHODS

Consecutive patients with chronic hepatitis C who had undergone liver biopsy between 1998 and 2004 were eligible. We used the three methods to evaluate patients at baseline and at follow-up (4-10 years later). When these methods yielded discordant or indeterminate results, a second liver biopsy was performed. Logistic regression models were fitted for each method to predict whether cirrhosis would appear and to predict long-term mortality from cirrhosis.

RESULTS

We included 289 patients in our study. The mean scores at baseline and at follow-up, respectively, were as follows: Forns, 5.47 ± 1.95 and 6.56 ± 2.02; APRI, 1.1 ± 2.33 and 1.4 ± 1.53; and NIHCED, 7.79 ± 11.45 and 15.48 ± 15.28. The area under the receiver operating characteristic curve for predicting cirrhosis was 0.83 for Forns, 0.79 for APRI, and 0.76 for NIHCED. The sensitivity and specificity for predicting cirrhosis, respectively, were 75 and 71% for Forns (cutoff 4.7), 86 and 42% for APRI (cutoff 0.48), and 41 and 82% for NIHCED (cutoff 0). The area under the receiver operating characteristic curve for predicting mortality was 0.86 for Forns, 0.79 for APRI, and 0.84 for NIHCED.

CONCLUSION

Indirect noninvasive markers could help identify patients with chronic hepatitis C at risk of progression to cirrhosis.

Non-invasive assessment of liver fibrosis in C282Y homozygous HFE hemochromatosis

BACKGROUND & AIMS

C282Y homozygotes with serum ferritin (SF) levels >1000 μg/L and/or increased serum transaminase levels are at risk of severe F3/F4 fibrosis. Current practical guidelines recommend liver biopsy in such individuals. This prospective observational cohort study aimed to evaluate non-invasive alternative means such as hyaluronic acid (HA) and transient elastography (TE) for the assessment of severe fibrosis in patients with SF >1000 μg/L or elevated transaminases.

METHODS

Between September 2005 and April 2013, 77 patients diagnosed C282Y homozygotes underwent a liver biopsy because of SF >1000 μg/L and/or increased transaminases according to current guidelines, with concomitant TE. All of them had clinical and biological evaluation, including HA measurement in 52 cases.

RESULTS

A total of 19.5% of patients had F3-F4 severe fibrosis. HA was higher in patients with severe fibrosis, but did not accurately predict severe fibrosis. TE was significantly higher in patients with severe fibrosis (17.2 vs. 4.9 kPa; P < 0.05) and was able to accurately predict fibrosis stage in 47/61 (77%) patients with valid measurement using a lower threshold of 6.4 kPa and an upper threshold of 13.9 kPa. Efficient assessment of severe fibrosis was not possible in patients with intermediate TE values.

CONCLUSION

An algorithm that successively employed SF and TE can accurately classify severe fibrosis in 61% of patients, restricting the need for liver biopsy to the 39% of patients with intermediate or unvalid TE values. This algorithm should be validated in independent cohorts before extended use.

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

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

Real-time shear-wave elastography: applicability, reliability and accuracy for clinically significant portal hypertension

BACKGROUND & AIMS

Real-time shear wave elastography (RT-SWE) might be useful to assess the severity of portal hypertension; reliability criteria for measurement are needed.

METHODS

We prospectively included 88 consecutive patients undergoing hepatic venous pressure gradient measurement (HVPG, reference standard) for portal hypertension. Liver stiffness (LS) was measured by RT-SWE and by transient elastography (TE). Spleen stiffness (SS) was measured by RT-SWE. Reliability criteria for RT-SWE were searched, and the accuracy of these techniques to identify HVPG ⩾10mmHg (clinically significant portal hypertension, CSPH) was tested and internally validated by bootstrapping analysis.

RESULTS

LS and SS by RT-SWE were feasible respectively in 87 (99%) and 58 (66%) patients. Both correlated with HVPG (LS: R=0.611, p<0.0001 and SS: R=0.514, p<0.0001). LS performed well for diagnosing CSPH (optimism corrected AUROC=0.858). Reliability of measurements was influenced by standard deviation (SD)/median ratio and depth. SD/median ⩽0.10 and depth of measurement <5.6cm were associated to 96.3% well classified for CSPH, while when one or none of the criteria were fulfilled the rates were 76.4% and 44.4%, respectively. Measurements fulfilling at least one criterion were considered acceptable; in these patients, RT-SWE performance to detect CSPH was excellent (AUROC=0.939; 95% CI: 0.865-1.000; p<0.0001; best cut-off: 15.4kPa). LS by RT-SWE and by TE were strongly correlated (R=0.795, p<0.0001) and performed similarly both in "per protocol" and in "intention-to-diagnose" analysis after applying reliability criteria.

CONCLUSIONS

LS by RT-SWE is an accurate method to diagnose CSPH if reliability criteria (SD/median ⩽0.10 and/or depth <5.6cm) are fulfilled.

Accuracy of fibroscan, compared with histology, in analysis of liver fibrosis in patients with hepatitis B or C: a United States multicenter study

BACKGROUND & AIMS

Liver biopsy is invasive and associated with complications, sampling errors, and observer variability. Vibration-controlled transient elastography (VCTE) with FibroScan can be used to immediately assess liver stiffness. We aimed to define optimal levels of liver stiffness to identify patients with chronic viral hepatitis and significant fibrosis, advanced fibrosis, or cirrhosis.

METHODS

In a prospective, 2-phase study, patients with chronic hepatitis C or B underwent VCTE followed by liver biopsy analysis from January 2005 through May 2008 at 6 centers in the United States. In phase 1 we identified optimal levels of liver stiffness for identification of patients with stage F2-F4 or F4 fibrosis (the development phase, n = 188). In phase 2 we tested these cutoff values in a separate cohort of patients (the validation phase, n = 560). All biopsies were assessed for METAVIR stage by a single pathologist in the phase 1 analysis and by a different pathologist in the phase 2 analysis. Diagnostic performances of VCTE were assessed by area under the receiver operating characteristic curve (AUROC) analyses.

RESULTS

In phase 1 of the study, liver stiffness measurements identified patients with ≥ F2 fibrosis with AUROC value of 0.89 (95% confidence interval, 0.83-0.92) and identified patients with F4 fibrosis with AUROC value of 0.92 (95% confidence interval, 0.87-0.95). Liver stiffness cutoff values (kPa) in phase 1 were 8.4 for ≥ F2 (82% sensitivity, 79% specificity) and 12.8 for F4 (84% sensitivity, 86% specificity). In the phase 2 analysis, the liver stiffness cutoff values identified patients with ≥ F2 fibrosis with 58% sensitivity (P < .0001 vs phase 1) and 75% specificity (nonsignificant difference vs phase 1); they identified patients with F4 fibrosis with 76% sensitivity (P < .0001 vs phase 1) and 85% specificity (nonsignificant differences vs phase 1). VCTE had an interobserver agreement correlation coefficient of 0.98 (n = 26) and an intraobserver agreement correlation coefficient of 0.95 (n = 34).

CONCLUSIONS

In a large U.S. multicenter study, we confirmed that VCTE provides an accurate assessment of liver fibrosis in patients with chronic viral hepatitis. Our findings are similar to those from European and Asian cohorts.

Significant variations in elastometry measurements made within short-term in patients with chronic liver diseases

BACKGROUND & AIMS

Transient elastometry is a noninvasive procedure used to measure fibrosis when patients are diagnosed with liver disease; it might be used to monitor changes over time. We investigated whether there are short-term variations in stiffness measurements that are not attributable to changes in fibrosis by studying patients with stable liver disease.

METHODS

We performed a retrospective analysis of 531 paired liver stiffness measurements made by Fibroscan when the study began (LSM1) and at follow-up (LSM2), more than 1 day and less than 1 year apart, from 432 stable (for body mass index, waist circumference, and alcohol consumption), untreated, immunocompetent patients with chronic liver disease (from January 2006 through March 2009). Variations between the first and follow-up measurements were expressed as absolute (LSM2-LSM1, kPa) or relative ([LSM2-LSM1]/LSM1*100) or as changes in fibrosis stage.

RESULTS

There was >20% variation in 49.7%, >30% in 34.3%, and >50% in 12.2% of paired measurements; this variation was constant across the spectrum of LSM1 values. The variations produced a 1-fibrosis stage difference in 31.5% of pairs and a ≥ 2-stage difference in 9.8% of pairs. Patients with LSM1 >7 kPa had increased probability of having a different stage of fibrosis at LSM2, compared with patients with LSM1 <7 kPa. Factors associated with variation included measurements made by 2 different operators or at least 1 non-senior operator, ratios of interquartile range:median values, significant fibrosis (≥ 7 kPa) at LSM1, baseline body mass index, or a 2-fold difference in level of alanine aminotransferase between measurements. When the analyses were restricted to measurements made by the same operator, the variation was slightly reduced; fibrosis stage differed between measurements for only 34.3% of cases.

CONCLUSIONS

Operator-related and patient-related factors produce significant variations in liver stiffness measurements made by transient elastometry, limiting its use in monitoring patients. These variations are unrelated to disease progression. The lowest levels of variation occur in measurements made in patients with no or early-stage fibrosis or by a single experienced operator.

Applicability and accuracy improvement of transient elastography using the M and XL probes by experienced operators

Transient elastography (TE) is the reference method to obtain liver stiffness measurements (LSM), but no results are obtained in 3.1% and unreliable in 15.8%. We assessed the applicability and diagnostic accuracy of TE re-evaluation using M and XL probes. From March 2011 to April 2012 868 LSM were performed with the M probe by trained operators (50-500 studies) (LSM1). Measurements were categorized as inadequate (no values or ratio <60% and/or IQR/LSM >30%) or adequate. Inadequate LSM1 were re-evaluated by experienced operators (>500 explorations) (LSM2) and inadequate LSM2 using XL probe (LSMXL). Inadequate LSM1 were obtained in 187 (21.5%) patients, IQR/LSM >30% in 97 (51%), ratio <60% in 24 (13%) and TE failed to obtain a measurement in 67 (36%). LSM2 achieved adequate registers in 123 (70%) of 175 registers previously considered as inadequate. Independent variables (OR, 95%CI) related to inadequate LSM1 were body mass index (1.11, 1.04-1.18), abdominal circumference (1.03, 1.01-1.06) and age (1.03, 1.01-1.04) and to inadequate LSM2 were skin-capsule distance (1.21, 1.09-1.34) and abdominal circumference (1.05, 1.01-1.10). The diagnostic accuracy (AUROC) to identify significant fibrosis improved from 0.89 (LSM1) to 0.91 (LSM2) (P = 0.046) in 334 patients with liver biopsy or clinically significant portal hypertension. A third evaluation (LSMXL) obtained adequate registers in 41 (93%) of 44 patients with inadequate LSM2. Operator experience increases the applicability and diagnostic accuracy of TE. The XL probe may be recommended for patients with inadequate values obtained by experienced operators using the M probe. http://clinicaltrials.gov (NCT01900808).

Australian Liver Association (ALA) expert consensus recommendations for the use of transient elastography in chronic viral hepatitis

Since the introduction of Transient Elastography (TE) into Australia in 2008, non-invasive liver fibrosis assessments have integrated themselves into clinical hepatology. The Australian Liver Association (ALA) recognizes these technologies perform an important role in the assessment of chronic viral hepatitis B and C. However, in the setting of viral hepatitis and many other chronic liver diseases, there remains no consensus or guidelines regarding the performance, utility or reporting of TE. Accordingly, the ALA sought to produce an expert consensus statement for the use of TE in chronic viral hepatitis. The recommendations incorporated in this document are based upon a thorough literature review and draw on extensive clinical experience using TE. The initial draft was presented at Australian Gastroenterology Week (AGW) 2013. Through a collaborative process and expert external review a finalized document was presented at AGW 2014.

New reliability criteria for transient elastography increase the number of accurate measurements for screening of cirrhosis and portal hypertension

BACKGROUND & AIMS

Transient elastography (TE) can non-invasively diagnose cirrhosis and portal hypertension (PHT). New TE reliability criteria suggest classifying measurements as very reliable (IQR/M < 0.1), reliable (IQR<0.3 or >0.3, if TE < 7.1 kPa) and poorly reliable (IQR/M > 0.3, if TE > 7.1 kPa). Compare traditional (reliable: success rate >60% + IQR/M ≤ 0.30) and new TE quality criteria (accurate: very reliable + reliable) regarding their diagnostic accuracy for cirrhosis and PHT and to identify potential confounders (age, aetiology, necroinflammatory activity, steatosis, siderosis, cholestasis, aminotransferases) of TE performance.

METHODS

Patients undergoing simultaneous measurements of TE, portal pressure (hepatic venous pressure gradient, HVPG) and liver biopsy were analysed.

RESULTS

Among 226 patients (48.7 ± 13.1 years, 74.7% male, 75.7% viral aetiology, 57% F3/F4), traditional TE quality criteria identified 71.6% reliable measurements, while new criteria yielded in 83.2% accurate results. Reliable TE values according to both criteria significantly correlated with fibrosis stage (r = 0.648 vs. r = 0.636) and HVPG (r = 0.836 vs. r = 0.846). Diagnostic accuracy for cirrhosis (cut-off >14.5 kPa) was 76.5% (AUC: 0.863) and 75.0% (AUC: 0.852) for traditional and new TE criteria, respectively, while for predicting HVPG ≥ 10 mmHg (>16.1 kPa), the accuracies were 88.9% (AUC: 0.957) and 89.8% (AUC: 0.962). New TE criteria allowed a better discrimination of reliable and non-reliable results for prediction of fibrosis and CSPH. Only aetiology and aminotransferases were independent confounders of the correlation of TE and fibrosis stage, while no confounder affected the correlation of TE and HVPG.

CONCLUSIONS

New reliability criteria for TE measurements increase the number of patients with accurate measurements without affecting diagnostic performance for detecting cirrhosis and portal hypertension. Aetiology of liver disease and aminotransferases should be considered when assessing liver fibrosis by TE.

Prognostic value of the combined use of transient elastography and fibrotest in patients with chronic hepatitis B

BACKGROUND & AIMS

Liver stiffness (LS) measurement using transient elastography and the FibroTest (FT) are alternatives to liver biopsy (LB) in assessing liver fibrosis. We investigated the prognostic role of the combined use of LS and FT in predicting liver-related events (LREs) in patients with chronic hepatitis B (CHB).

METHODS

Consecutive patients with CHB who underwent LB, along with LS and FT on the same day were recruited. LRE was defined as hepatic decompensation, hepatocellular carcinoma (HCC) or liver-related death.

RESULTS

A total of 151 patients (86 male) were analyzed. During follow-up (median 59.9 months), overall 18 (11.9%) patients experienced LREs. The areas under receiver-operating characteristic curves of LS, FT, LS + FT and LS × FT in predicting LRE were 0.701, 0.668, 0.702 and 0.741 respectively. After adjusting for age and histological fibrosis staging, significant variables in univariate analysis (both P < 0.05), LS + FT and LS × FT were independent predictors of LREs with hazard ratios (HRs) of 1.080 and 1.126 (all P < 0.05) respectively. When subjects were divided into three groups according to quartile stratification (low quartile, interquartile and high quartile) using LS + FT and LS × FT, cumulative LRE development rate significantly increased with a corresponding increase in value among three groups respectively (log-rank test, all P < 0.05).

CONCLUSION

The combined use of LS and FT significantly predicted forthcoming LRE development, but with only a slight additional benefit compared to LS or FT alone.

Controlled attenuation parameter for noninvasive assessment of hepatic steatosis using Fibroscan®: validation in chronic hepatitis B

BACKGROUND AND AIM

The controlled attenuation parameter (CAP) using transient elastography (TE) was validated in chronic hepatitis C to evaluate hepatic steatosis; however, limited data are available on chronic hepatitis B (CHB). Therefore, we assessed the accuracy and the efficacy of CAP for the detection of steatosis in CHB.

METHODS

Consecutive CHB patients underwent liver biopsy and liver stiffness measurements (LSM) with simultaneous CAP determination using the M probe of the TE. The area under the receiver operating characteristics curve (AUROC) was used to evaluate the performance of CAP in diagnosing steatosis compared with biopsy.

RESULTS

A total of 340 patients were included: 60 % were male, the median age was 37 years; the body mass index (BMI) was ≥ 28 kg/m(2) for 14 % of the subjects; and the distribution of the steatosis grade was S0 58.2 %, S1 34.2 %, S2 5.0 % and S3 2.6 %. The median (range) of CAP was 218 (100-400) dB/m, and CAP correlated with the BMI (ρ = 3.622) and steatosis grade (ρ = 29.203) according to a multivariate analysis (both P < 0.001). CAP could detect the different grades of steatosis: ≥ S1 with AUROC of 0.81 at a cutoff of 224 dB/m, ≥ S2 with AUROC of 0.90 at a cutoff of 236 dB/m and ≥ S3 with AUROC of 0.97 at a cutoff of 285 dB/m. Furthermore, the LSM and fibrosis and activity grades on biopsy did not influence the CAP performance.

CONCLUSIONS

CAP presented excellent diagnostic performance for severe steatosis with high sensitivity and specificity in Chinese patients with CHB.

Comparison of liver fibrosis progression in HIV/HCV co-infected and HCV mono-infected patients by transient elastometry

Monitoring of liver fibrosis (LF) is an essential tool for preventing liver-related complications in HIV/HCV co-infected patients. In this study, we compared LF progression by transient elastometry (TE) in 50 HIV/HCV co-infected and 115 HCV mono-infected patients followed in our institution between June 2006 and December 2011. Patients naive to interferon therapy and with at least two measurements of liver stiffness by TE were included. In all, 76% of HIV/HCV co-infected and 75% of HCV mono-infected patients remained in the same stage of LF over time. Conversely, 19% and 15% of HIV/HCV co-infected and HCV mono-infected subjects, respectively, had progression to advanced LF (≥ F3). Our study found a similar proportion of HIV/HCV co-infected and HCV mono-infected patients that developed an advanced LF during the follow-up time considered. Alcohol abuse was the only factor significantly associated with the progression as evidenced by multiple quantile regression analysis.

Usefulness of transient elastography by FibroScan for the evaluation of liver fibrosis

INTRODUCTION

Liver stiffness measurement (LSM) is used for the assessment of liver fibrosis. However, there is limited data in Indian patients.

AIMS AND OBJECTIVE

The aim of this study was to find the correlation of LSM, aspartate transaminase to platelet ratio index (APRI) with fibrosis as assessed by liver biopsy (LB), and predictors of discordance between LB and LSM.

METHODS

One hundred and eighty-five consecutive patients who underwent liver biopsy and transient elastography (TE) were enrolled. Fibrosis was graded by two independent pathologists using the METAVIR classification. Area under receiver operating curves (AUROC) was used to evaluate the accuracy of transient elastography and APRI in diagnosing significant fibrosis (F>2) and cirrhosis (F4).

RESULTS

Predominant etiologies were hepatitis B (46 %) and hepatitis C (26 %). LSM was unsuccessful in ten patients (5 %) because of small intercostal space (n = 3) and obesity (n = 7). Fibrosis is significantly correlated with LSM (r = 0.901, p = 0.001) and APRI (r = 0.736, p = 0.001). There was a significant difference in median LSM value in patients with no fibrosis (F0) in comparison to patients having mild fibrosis [mild portal fibrosis (F1) + fibrosis with few septa (F2)] (4.5 vs. 7.5 kPa, p = 0.001) and advanced fibrosis [bridging fibrosis that is spreading and connecting to other areas that contain fibrosis (F3) + cirrhosis or advanced scarring of the liver (F4)] (4.5 vs. 19.4 kPa, p = 0.001). Similarly, there was a significant difference in mean APRI value in patients with F0 in comparison to patients having mild fibrosis (F1 + F2) (0.55 ± 0.31 vs. 1.09 ± 0.81, p = 0.001) and advanced fibrosis (F3 + F4) (2.3 ± 1.3, p = 0.001). AUROC for diagnosis of significant fibrosis was 0.98 (95 % confidence interval (CI) 0.963-0.999) for TE and 0.865 (95 % CI 0.810-0.920) for APRI. Optimal TE value was 10.0 kPa for diagnosis of significant fibrosis and 14.7 kPa for cirrhosis with specificity and sensitivity of 89 %, 98 % and 96 %, and 97 %, respectively. On multivariate analysis, total bilirubin and histological activity index (HAI) were identified as an independent predictor of TE inaccuracy.

CONCLUSION

LSM is a reliable predictor of hepatic fibrosis in Indian patients. LSM is superior to APRI for noninvasive diagnosis of hepatic fibrosis and cirrhosis, and high bilirubin (10.5 mg/dL) and Ishak HAI grade (>11) were independent predictors of discordance between LB and LSM.

Chronic hepatitis C and liver fibrosis

Chronic infection with hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality worldwide and predisposes to liver fibrosis and end-stage liver complications. Liver fibrosis is the excessive accumulation of extracellular matrix proteins, including collagen, and is considered as a wound healing response to chronic liver injury. Its staging is critical for the management and prognosis of chronic hepatitis C (CHC) patients, whose number is expected to rise over the next decades, posing a major health care challenge. This review provides a brief update on HCV epidemiology, summarizes basic mechanistic concepts of HCV-dependent liver fibrogenesis, and discusses methods for assessment of liver fibrosis that are routinely used in clinical practice. Liver biopsy was until recently considered as the gold standard to diagnose and stage liver fibrosis. However, its invasiveness and drawbacks led to the development of non-invasive methods, which include serum biomarkers, transient elastography and combination algorithms. Clinical studies with CHC patients demonstrated that non-invasive methods are in most cases accurate for diagnosis and for monitoring liver disease complications. Moreover, they have a high prognostic value and are cost-effective. Non-invasive methods for assessment of liver fibrosis are gradually being incorporated into new guidelines and are becoming standard of care, which significantly reduces the need for liver biopsy.

Chronic permanent hypoxemia predisposes to mild elevation of liver stiffness

AIM: To evaluate the impact of long term permanent hypoxemia noticed in patients with non operated congenital cyanogenic cyanotic cardiopathy on liver stiffness.

METHODS: We included ten adult patients with non operated inoperate cyanotic cardiopathy and ten matched patients for age and gender admitted to the gastroenterology department for proctologic diseases; Clinical and laboratory data were collected [age, gender, body mass index, oxygen saturation, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), glycemia and cholesterol]. Measurement of hepatic stiffness by transient elastography was carried out in all patients using the Fibroscan device. All patients underwent an echocardiography to eliminate congestive heart failure.

RESULTS: Among the patients with cyanotic cardiopathy, median liver stiffness 5.9 ± 1.3 kPa was greater than control group (4.7 ± 0.4 kPa) (P = 0.008). Median levels of GOT, GPT, gamma-glutamyltransferase, glycemia and cholesterol were comparable in cardiopathy and control group. In regression analysis including age, gender, body mass index, oxygen saturation, GOT, GPT, glycemia, cholesterol showed that only oxygen saturation was related to liver stiffness (r = -0.63 P = 0.002).

CONCLUSION: Chronic permanent hypoxemia can induce mild increase of liver stiffness, but further studies are needed to explore the histological aspects of liver injury induced by chronic permanent hypoxemia.

Shear-wave elastography: a noninvasive tool for monitoring changing hepatic venous pressure gradients in patients with cirrhosis

PURPOSE

To investigate whether liver stiffness ( LS liver stiffness ) and change in LS liver stiffness measurements ( ΔLS change in LS ) at shear-wave elastography ( SWE shear-wave elastography ) correlates with the hepatic venous pressure gradient ( HVPG hepatic venous pressure gradient ) and to assess the feasibility of using SWE shear-wave elastography to estimate the change in HVPG hepatic venous pressure gradient ( ΔHVPG change in HVPG ) in patients with portal hypertension.

MATERIALS AND METHODS

Institutional review board approval was obtained, with waiver of informed consent. Between September 2010 and October 2012, 97 consecutive patients who were given a diagnosis of portal hypertension on the basis of HVPG hepatic venous pressure gradient measurement were included. Among these patients, 23 who underwent follow-up HVPG hepatic venous pressure gradient measurement to evaluate response to treatment were included in the follow-up group. The correlation between HVPG hepatic venous pressure gradient and LS liver stiffness was analyzed by using the Pearson correlation test. In the follow-up group, whether ΔHVPG change in HVPG was correlated with ΔLS change in LS was also evaluated. Thereafter, the areas under the receiver operating characteristic curves ( AUC area under the ROC curve s) were calculated to determine the diagnostic performances of ΔLS change in LS and the second LS liver stiffness measurement after medical treatment and to compare their performances in association with clinical improvement and aggravation of portal hypertension.

RESULTS

LS liver stiffness was moderately correlated with HVPG hepatic venous pressure gradient (r = 0.593) in the single-measurement group. There was also a strong correlation between ΔLS change in LS and ΔHVPG change in HVPG (r = 0.863). At comparison of the second LS liver stiffness measurement, ΔLS change in LS showed no significant difference in AUC area under the ROC curve in patients with improvement (0.627 vs 0.794, P = .201) but showed higher AUC area under the ROC curve in association with aggravation of portal hypertension (0.925 vs 0.611, P = .026).

CONCLUSION

Estimating ΔHVPG change in HVPG by using SWE shear-wave elastography may be useful in patients with cirrhosis and portal hypertension.

Controlled attenuation parameter for evaluating liver steatosis in chronic viral hepatitis

AIM: To assess the performance of controlled attenuation parameter (CAP) in patients with chronic viral hepatitis.

METHODS: CAP is a new technique that measures the attenuation in the liver of an ultrasound beam, which is directly related to lipid accumulation. Consecutive patients undergoing liver biopsy for chronic viral hepatitis were studied using the M probe of FibroScan device (Echosens, Paris, France). The device estimates liver steatosis in decibel per meter (dB/m). An expert operator performed all measurements. Steatosis was graded according to Kleiner’s classification. Pearson or Spearman rank coefficient was used to test correlation between two study variables. Linear regression was used for multivariate model to assess the association between CAP and other variables. Receiver operating characteristic curve analysis was performed to calculate area under the curve (AUROC) for S0 vs S1-S3 and S0-S1 vs S2-S3.

RESULTS: 115 subjects (85 males and 30 females) were prospectively studied. The mean values of CAP were 227.1 ± 43.1 for S0; 254.6 ± 38.9 for S1; 297.8 ± 49.4 dB/m for S2-S3. In univariate analysis CAP showed a significant correlation with age, body mass index (BMI), degree of steatosis, and cholesterol. Multivariate regression analysis confirmed the correlation with the degree of steatosis [coefficient, 1.2 (0.60-1.83); P < 10^-5] and BMI [coefficient, 4.1 (0.5-7.8); P = 0.03] but not with all other variables. Optimal cutoff values for S ≥ 1 and S ≥ 2 were 219 dB/m [AUROC, 0.76 (0.67-0.84); sensitivity, 91.1% (78.8-97.5); specificity, 51.6% (38.7-64.2); positive predictive value, 56.9% (44.7-68.6); negative predictive value, 89.2% (74.3-97.0); positive likelihood ratio, 1.88 (1.4-2.5); negative likelihood ratio, 0.17 (0.07-0.5)] and 296 dB/m [AUROC, 0.82 (0.74-0.89); sensitivity, 60.0% (32.3-83.7); specificity, 91.5% (83.9-96.3); positive predictive value, 52.9% (27.8-77.0); negative predictive value, 93.5% (86.3-97.6); positive likelihood ratio, 7.05 (3.2-15.4); negative likelihood ratio, 0.44 (0.2-0.8)], respectively.

CONCLUSION: Controlled attenuation parameter could be a useful tool in the clinical management of patients with chronic viral hepatitis for detecting liver steatosis.

Factors affecting the accuracy of controlled attenuation parameter (CAP) in assessing hepatic steatosis in patients with chronic liver disease

Background & Aims

Controlled attenuation parameter (CAP) can measure hepatic steatosis. However, factors affecting its accuracy have not been described yet. This study investigated predictors of discordance between liver biopsy (LB) and CAP.

Methods

A total of 161 consecutive patients with chronic liver disease who underwent LB and CAP were enrolled prospectively. Histological steatosis was graded as S0 (<5%), S1 (5–33%), S2 (34–66%), and S3 (>66% of hepatocytes). Cutoff CAP values were calculated from our cohort (250, 301, and 325 dB/m for ≥S1, ≥S2, and S3). Discordance was defined as a discrepancy of at least two steatosis stages between LB and CAP.

Results

The median age (102 males and 59 females) was 49 years. Repartition of histological steatosis was as follows; S0 26.1% (n = 42), S1 49.7% (n = 80), S2 20.5% (n = 33), and S3 3.7% (n = 6). In multivariate linear regression analysis, CAP value was independently associated with steatosis grade along with body mass index (BMI) and interquartile range/median of CAP value (IQR/M_CAP) (all P<0.05). Discordance was identified in 13 (8.1%) patients. In multivariate analysis, histological S3 (odd ratio [OR], 9.573; 95% confidence interval [CI], 1.207–75.931; P = 0.033) and CAP value (OR, 1.020; 95% CI, 1.006–1.034; P = 0.006) were significantly associated with discordance, when adjusting for BMI, IQR/M_CAP, and necroinflammation, reflected by histological activity or ALT level.

Conclusions

Patients with high grade steatosis or high CAP values have a higher risk of discordance between LB and CAP. Further studies are needed to improve the accuracy of CAP interpretation, especially in patients with higher CAP values.

Quantitative liver MRI combining phase contrast imaging, elastography, and DWI: assessment of reproducibility and postprandial effect at 3.0 T

PURPOSE

To quantify short-term reproducibility (in fasting conditions) and postprandial changes after a meal in portal vein (PV) flow parameters measured with phase contrast (PC) imaging, liver diffusion parameters measured with multiple b value diffusion-weighted imaging (DWI) and liver stiffness (LS) measured with MR elastography (MRE) in healthy volunteers and patients with liver disease at 3.0 T.

MATERIALS AND METHODS

In this IRB-approved prospective study, 30 subjects (11 healthy volunteers and 19 liver disease patients; 23 males, 7 females; mean age 46.5 y) were enrolled. Imaging included 2D PC imaging, multiple b value DWI and MRE. Subjects were initially scanned twice in fasting state to assess short-term parameter reproducibility, and then scanned 20 min. after a liquid meal. PV flow/velocity, LS, liver true diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (PF) and apparent diffusion coefficient (ADC) were measured in fasting and postprandial conditions. Short-term reproducibility was assessed in fasting conditions by measuring coefficients of variation (CV) and Bland-Altman limits of agreement. Differences in MR metrics before and after caloric intake and between healthy volunteers and liver disease patients were assessed.

RESULTS

PV flow parameters, D, ADC and LS showed good to excellent short-term reproducibility in fasting state (CV <16%), while PF and D* showed acceptable and poor reproducibility (CV = 20.4% and 51.6%, respectively). PV flow parameters and LS were significantly higher (p<0.04) in postprandial state while liver diffusion parameters showed no significant change (p>0.2). LS was significantly higher in liver disease patients compared to healthy volunteers both in fasting and postprandial conditions (p<0.001). Changes in LS were significantly correlated with changes in PV flow (Spearman rho = 0.48, p = 0.013).

CONCLUSIONS

Caloric intake had no/minimal/large impact on diffusion/stiffness/portal vein flow, respectively. PC MRI and MRE but not DWI should be performed in controlled fasting state.

The feasibility and reliability of transient elastography using Fibroscan®: a practice audit of 2335 examinations

BACKGROUND

Liver stiffness measurement (LSM) using transient elastography is widely used in the management of patients with chronic liver disease.

OBJECTIVES

To examine the feasibility and reliability of LSM, and to identify patient and operator characteristics predictive of poorly reliable results.

METHODS

The present retrospective study investigated the frequency and determinants of poorly reliable LSM (interquartile range [IQR]⁄median LSM [IQR⁄M] >30% with median liver stiffness ≥7.1 kPa) using the FibroScan (Echosens, France) over a three-year period. Two experienced operators performed all LSMs. Multiple logistic regression analyses examined potential predictors of poorly reliable LSMs including age, sex, liver disease, the operator, operator experience (<500 versus ≥500 scans), FibroScan probe (M versus XL), comorbidities and liver stiffness. In a subset of patients, medical records were reviewed to identify obesity (body mass index ≥30 kg⁄m2).

RESULTS

Between July 2008 and June 2011, 2335 patients with liver disease underwent LSM (86% using the M probe). LSM failure (no valid measurements) occurred in 1.6% (n=37) and was more common using the XL than the M probe (3.4% versus 1.3%; P=0.01). Excluding LSM failures, poorly reliable LSMs were observed in 4.9% (n=113) of patients. Independent predictors of poorly reliable LSM included older age (OR 1.03 [95% CI 1.01 to 1.05]), chronic pulmonary disease (OR 1.58 [95% CI 1.05 to 2.37), coagulopathy (OR 2.22 [95% CI 1.31 to 3.76) and higher liver stiffness (OR per kPa 1.03 [95% CI 1.02 to 1.05]), including presumed cirrhosis (stiffness ≥12.5 kPa; OR 5.24 [95% CI 3.49 to 7.89]). Sex, diabetes, the underlying liver disease and FibroScan probe were not significant. Although reliability varied according to operator (P<0.0005), operator experience was not significant. In a subanalysis including 434 patients with body mass index data, obesity influenced the rate of poorly reliable results (OR 2.93 [95% CI 0.95 to 9.05]; P=0.06).

CONCLUSIONS

FibroScan failure and poorly reliable LSM are uncommon. The most important determinants of poorly reliable results are older age, obesity, higher liver stiffness and the operator, the latter emphasizing the need for adequate training.

Precise evaluation of liver histology by computerized morphometry shows that steatosis influences liver stiffness measured by transient elastography in chronic hepatitis C

BACKGROUND

Liver stiffness evaluation (LSE) by Fibroscan is now widely used to assess liver fibrosis in chronic hepatitis C. Liver steatosis is a common lesion in chronic hepatitis C as in other chronic liver diseases, but its influence on LSE remains unclear. We aimed to precisely determine the influence of steatosis on LSE by using quantitative and precise morphometric measurements of liver histology.

METHODS

650 patients with chronic hepatitis C, liver biopsy, and LSE were included. Liver specimens were evaluated by optical analysis (Metavir F and A, steatosis grading) and by computerized morphometry to determine the area (%, reflecting quantity) and fractal dimension (FD, reflecting architecture) of liver fibrosis and steatosis.

RESULTS

The relationships between LSE and liver histology were better described using morphometry. LSE median was independently linked to fibrosis (area or FD), steatosis (area or FD), activity (serum AST), and IQR/LSE median. Steatosis area ≥4.0 % induced a 50 % increase in LSE result in patients with fibrosis area <9 %. In patients with IQR/LSE median ≤0.30, the rate of F0/1 patients misclassified as F ≥ 2 by Fibroscan was, respectively for steatosis area <4.0 and ≥4.0 %: 12.6 vs 32.4 % (p = 0.003). Steatosis level did not influence LSE median when fibrosis area was ≥9 %, and consequently did not increase the rate of F ≤ 3 patients misclassified as cirrhotic.

CONCLUSION

A precise evaluation of liver histology by computerized morphometry shows that liver stiffness measured by Fibroscan is linked to liver fibrosis, activity, and also steatosis. High level of steatosis induces misevaluation of liver fibrosis by Fibroscan.

Clinical benefit of liver stiffness measurement at 3 months after Kasai hepatoportoenterostomy to predict the liver related events in biliary atresia

BACKGROUND

The progression of hepatic fibrosis may result in decompensated hepatic failure with cirrhosis, liver related events (LRE) such as ascites, variceal bleeding, and death after successful and timely Kasai hepatoportoenterostomy (HPE) in biliary atresia. The aim of this study is to suggest clinical benefit of the liver stiffness measurement (LSM) using transient elastography at 3 months after the Kasai operation to predict LRE.

METHODS

Between January 2007 and December 2011, 69 eligible biliary atresia patients who underwent Kasai HPE and performed transient elastography before and 3 months after HPE were included. The occurrences of LRE were analyzed for all patients. All patients were divided into 2 groups (with and without LRE) for comparison. Multivariate analysis was used to detect the independent risk factors of LRE. The area under the receiver operation characteristics curve (AUROC) was used to establish the LSM optimal cutoff value of 3 months after Kasai operation in predicting LRE.

RESULTS

LSM value, aminotransferase, albumin, bilirubin, and PT-INR significantly differed among the two groups. Multivariate analysis demonstrated LSM value as the most powerful independent factor of the development of LRE. The cut-off value of 19.9 kPa was calculated to be optimal for predicting LRE development with total sensitivity and specificity of 1.804. AUROC resulted in 0.943, with sensitivity of 85.3% and specificity of 95.2%.

CONCLUSIONS

The LSM value of 3 months after Kasai HPE can be a useful predictor of LRE development.

Liver fibrosis progression in HIV-HCV-coinfected patients treated with distinct antiretroviral drugs and impact of pegylated interferon/ribavirin therapy

BACKGROUND

Advanced liver fibrosis frequently develops in patients with chronic hepatitis C coinfected with HIV. Non-invasive techniques for staging liver fibrosis, such as transient elastometry, may allow both periodic monitoring and examination of large patient populations.

METHODS

A programme of liver fibrosis assessment using transient elastometry has been ongoing at our institution since 2004. All HIV-HCV-coinfected patients having ≥2 examinations separated by >18 months were included. Liver fibrosis progression (LFP) was defined as an increase in liver stiffness from <9.5 kPa (Metavir F0-F2) to >9.5 kPa (Metavir F3-F4), or an increase >30% in patients with baseline Metavir F3-F4.

RESULTS

A total of 545 HIV-HCV-coinfected patients were analysed (mean age 41 years, 71% male, 81% intravenous drug users, mean body mass index 23.3 kg/m(2), 4.2% hepatitis B surface antigen-positive, 8.4% alcohol abuse, mean CD4(+) T-cell count 519 cells/μl). At baseline, 527 patients were on antiretroviral therapy, with the most frequent third drug being atazanavir (19.7%), efavirenz (15.9%), lopinavir (13.1%) or nevirapine (7.2%). A total of 99 (18%) patients experienced LFP during a mean (sd) follow-up of 70.9 (15.7) months. Use of protease inhibitors (OR 4.93, 95% CI 1.73, 14.0; P=0.03) and male gender (OR 5.12, 95% CI 1.37, 19.1; P=0.01) were associated with LFP. By contrast, the achievement of HCV clearance following pegylated interferon/ribavirin (PEG-IFN/RBV) therapy (OR 0.27, 95% CI 0.1, 0.79; P=0.02) was protective. Lopinavir exposure was significantly associated with LFP (OR 1.02, 95% CI 1.0, 1.04; P=0.03), whereas nevirapine was protective (OR 0.94, 95% CI 0.9, 0.99; P=0.02).

CONCLUSIONS

The use of protease inhibitors, mainly lopinavir, is associated with increased LFP in HIV-HCV-coinfected patients. By contrast, nevirapine therapy and, particularly, HCV clearance with PEG-IFN/RBV significantly reduce LFP.

Correlation of MR elastography with morphometric quantification of liver fibrosis (Fibro-C-Index) in chronic hepatitis B

PURPOSE

We evaluated the correlation of MR Elastography (MRE) with morphometric assessment of liver fibrosis in chronic hepatitis B (CHB).

METHODS

Thirty-two patients with CHB underwent both MRE and a liver biopsy within a 6-month interval. MRE was performed using standard MRE sequence on a 1.5 Tesla clinical scanner. The liver stiffness (LS) was measured on automatically generated stiffness maps. Morphometric quantification of fibrosis of liver biopsies was performed using a semi-automated image analysis program and expressed as percentage area (Fibro-C-Index). Correlations between MRE, Fibro-C-Index, and histologic fibrosis stages were evaluated. Receiver operating curve (ROC) analysis of MRE and Fibro-C-index for differentiating fibrosis (≥F1), significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) was performed.

RESULTS

MRE showed excellent correlation with both Fibro-C-Index (r = 0.78, 95% confidence interval [CI], 0.59-0.88, P < 0.001) and histologic staging (rho = 0.87, 95% CI, 0.72-0.94, P < 0.0001). Significant differences in MRE (P = 0.0001) and Fibro-C-Index (P = 0.003) among different stages of liver fibrosis was found. MRE and Fibro-C-Index had similar accuracies for differentiating fibrosis stages: ≥F1 (0.87 versus 0.81, P = 0.6), ≥F2 (0.95 versus 0.94, P = 0.78), ≥F3 (0.98 versus 0.96, P = 0.76), and F4 (1.00 versus 0.92, P = 0.10).

CONCLUSION

MRE is an excellent noninvasive indicator of liver fibrosis burden in CHB.

Liver elastography, comments on EFSUMB elastography guidelines 2013

Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography. The document is intended to form a reference and to guide clinical users in a practical way. They give practical advice for the use and interpretation. Liver disease forms the largest section, reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography. In this review comments and illustrations on the guidelines are given.

Hepatic and splenic stiffness augmentation assessed with MR elastography in an in vivo porcine portal hypertension model

PURPOSE

To investigate the influence of portal pressure on the shear stiffness of the liver and spleen in a well-controlled in vivo porcine model with magnetic resonance elastography (MRE). A significant correlation between portal pressure and tissue stiffness could be used to noninvasively assess increased portal venous pressure (portal hypertension), which is a frequent clinical condition caused by cirrhosis of the liver and is responsible for the development of many lethal complications.

MATERIALS AND METHODS

During multiple intraarterial infusions of Dextran-40 in three adult domestic pigs in vivo, 3D abdominal MRE was performed with left ventricle and portal catheters measuring blood pressure simultaneously. Least-squares linear regressions were used to analyze the relationship between tissue stiffness and portal pressure.

RESULTS

Liver and spleen stiffness have a dynamic component that increases significantly following an increase in portal or left ventricular pressure. Correlation coefficients with the linear regressions between stiffness and pressure exceeded 0.8 in most cases.

CONCLUSION

The observed stiffness-pressure relationship of the liver and spleen could provide a promising noninvasive method for assessing portal pressure. Using MRE to study the tissue mechanics associated with portal pressure may provide new insights into the natural history and pathophysiology of hepatic diseases and may have significant diagnostic value in the future.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Operator training requirements and diagnostic accuracy of Fibroscan in routine clinical practice

BACKGROUND

Fibroscan is a quick, non-invasive technique used to measure liver stiffness (kPa), which correlates with fibrosis. To achieve a valid liver stiffness evaluation (LSE) the operator must obtain all the following three criteria: (1) ≥10 successful liver stiffness measurements; (2) IQR/median ratio <0.30 and (3) ≥60% measurement success rate.

OBJECTIVES

To assess the operator training requirements and the importance of adhering to the LSE validity criteria in routine clinical practice.

METHODS

We retrospectively analysed the LSE validity rates of 2311 Fibroscans performed (1 August 2008 to 31 July 2011) in our tertiary liver outpatients department at the University Hospital Birmingham, UK. The diagnostic accuracy of Fibroscan was assessed in 153 patients, by comparing LSE (valid and invalid) with the modified Ishak fibrosis stage on liver biopsy.

RESULTS

Learning curve analysis highlighted that the greatest improvement in validity of LSE rates occurs in the operator's first 10 Fibroscans, reaching 64.7% validity by the 50th Fibroscan. The correlation between LSE and the fibrosis stage on liver biopsy was superior in patients with a valid LSE (n=97) compared with those with an invalid LSE (n=56) (rs 0.577 vs 0.259; p=0.022). Area under receiving operating characteristics for significant fibrosis was greater when LSE was valid (0.83 vs 0.66; p=0.048). Using an LSE cut-off of 8 kPa, the negative predictive value of valid LSE was superior to invalid LSE for the detection of significant (84% vs 71%) and advanced fibrosis (100% vs 93%).

CONCLUSIONS

Fibroscan requires minimal operator training (≥10 observed on patients), and when a valid LSE is obtained, it is an accurate tool for excluding advanced liver fibrosis. To ensure the diagnostic accuracy of Fibroscan it is essential that the recommended LSE validity criteria are adhered to in routine clinical practice.

Association of HIV infection, hepatitis C virus infection, and metabolic factors with liver stiffness measured by transient elastography

BACKGROUND

Few studies have examined the relationship of human immunodeficiency virus (HIV) monoinfection and its associated perturbations with liver fibrosis.

METHODS

USING multivariable linear regression, we examined the demographic, behavioral, metabolic and viral factors associated with transient elastography-measured liver stiffness in 314 participants (165 HIV positive/hepatitis C virus [HCV] negative, 78 HIV positive/HCV positive, 14 HIV negative/HCV positive, 57 HIV negative/HCV negative) in the Women's Interagency HIV Study.

RESULTS

Compared with HIV negative/HCV negative women, HIV positive/HCV positive women had higher median liver stiffness values (7.1 vs 4.4 kPa; P < .001); HIV positive/HCV negative and HIV negative/HCV negative women had similar liver stiffness values (both 4.4 kPa; P = .94). HIV/HCV coinfection remained associated with higher liver stiffness values (74% higher; 95% confidence interval [CI], 49-104) even after multivariable adjustment. Among HCV positive women, waist circumference (per 10-cm increase) was associated with 18% (95% CI, 7.5%-30%) higher liver stiffness values after multivariable adjustment; waist circumference showed little association among HIV positive/HCV negative or HIV negative/HCV negative women. Among HIV positive/HCV negative women, history of AIDS (13%; 95% CI, 4% -27%) and HIV RNA (7.3%; 95% CI, 1.59%-13.3%, per 10-fold increase) were associated with greater liver stiffness.

CONCLUSIONS

HCV infection but not HIV infection is associated with greater liver stiffness when infected women are compared with those with neither infection. Our finding that waist circumference, a marker of central obesity, is associated with greater liver stiffness in HIV/HCV-coinfected but not HIV-monoinfected or women with neither infection suggests that in the absence of HCV-associated liver injury the adverse effects of obesity are lessened.

Non-invasive assessment of liver fibrosis in patients with chronic hepatitis B

In patients with chronic hepatitis B (CHB), liver fibrosis assessment is essential not only for determining prognosis but also for identifying patients who should receive treatment. Liver biopsy is limited by its invasiveness and sampling error. To explore effective non-invasive methods for liver fibrosis assessment, we reviewed international literature published over the past decade that focused on patients with CHB. Biomarker panels such as API, FIB-4, Forns Index, HepaScore, FibroMeter, FibroTest, Zeng Index and Hui Index detect advanced fibrosis and cirrhosis with fairly satisfactory accuracy with area under the receiver-operating characteristics curve higher than 0.85. However, most panels and the suggested cutoffs have not been independently validated. Transient elastography is accurate in detecting advanced fibrosis and cirrhosis, and the relative cutoffs have been defined. False-positive results may, however, occur in cases of active necroinflammation and cholestasis. Other promising imaging methods such as acoustic radiation force impulse and magnetic resonance elastography still require further validating studies. We conclude that transient elastography, FibroTest and API are the most widely validated. Transient elastography has been validated as the most useful non-invasive method for liver fibrosis assessment. To improve non-invasive performance of detecting liver fibrosis, a combined application of transient elastography and biomarkers may be the preferred course of action.

Liver stiffness predicts liver-related complications and mortality in HIV patients with chronic hepatitis C on antiretroviral therapy

BACKGROUND

Liver disease is currently one of the leading causes of death in HIV individuals. Hepatic fibrosis largely mediates this effect and infection with hepatitis C virus (HCV) is the most common cause. Few studies have examined so far the predictive value of liver fibrosis staging on mortality and liver decompensation in HIV/HCV-coinfected patients.

METHODS

A prospective programme of liver fibrosis assessment using transient elastometry has been ongoing at our institution since 2004. Data from all HIV/HCV-coinfected patients who underwent a transient elastometry examination and have at least 18 months of follow-up were selected for the current analysis.

RESULTS

A total of 545 HIV/HCV-coinfected patients were examined (mean age 41 years, 71% men, 81% IDUs, mean BMI 23.3 kg/m2, HBsAg+ 4.2%, alcohol abuse 8.4%, mean CD4 cell count 519 cells/μl). The mean follow-up was 70.9 ± 15.7 months. During follow-up, 12 patients (2.2%) died, four of them due to hepatic complications. Liver-related events (ascites, encephalopathy, oesophageal varices or hepatocellular carcinoma) appeared in 53 patients (10%). In the multivariate analysis, baseline liver stiffness was the strongest predictor of liver-related complications [odds ratio (OR) 1.12, 95% confidence interval (CI) 1.08-1.16, P < 0.0001] and of all-cause mortality (OR 1.09, 95% CI 1.01-1.19, P = 0.02). The achievement of sustained virological response following peginterferon/ribavirin therapy during the study period was protective against the development of liver-related events (OR 0.02, 95% CI 0-0.23, P = 0.01).

CONCLUSION

Liver fibrosis staging, as measured by transient elastometry, predicts liver-related complications and all-cause mortality in HIV/HCV-coinfected patients on antiretroviral therapy.