A meta-analysis of transient elastography for the detection of hepatic fibrosis

Principles and clinical application of ultrasound elastography for diffuse liver disease

Accurate assessment of the degree of liver fibrosis is important for estimating prognosis and deciding on an appropriate course of treatment for cases of chronic liver disease (CLD) with various etiologies. Because of the inherent limitations of liver biopsy, there is a great need for non-invasive and reliable tests that accurately estimate the degree of liver fibrosis. Ultrasound (US) elastography is considered a non-invasive, convenient, and precise technique to grade the degree of liver fibrosis by measuring liver stiffness. There are several commercial types of US elastography currently in use, namely, transient elastography, acoustic radiation force impulse imaging, supersonic shear-wave imaging, and real-time tissue elastography. Although the low reproducibility of measurements derived from operator-dependent performance remains a significant limitation of US elastography, this technique is nevertheless useful for diagnosing hepatic fibrosis in patients with CLD. Likewise, US elastography may also be used as a convenient surveillance method that can be performed by physicians at the patients' bedside to enable the estimation of the prognosis of patients with fatal complications related to CLD in a non-invasive manner.

Shear wave elastography for liver stiffness measurement in clinical sonographic examinations: evaluation of intraobserver reproducibility, technical failure, and unreliable stiffness measurements

OBJECTIVES

The purpose of this study was to determine the optimal minimum number of liver stiffness measurements on shear wave elastography (SWE) and to evaluate the frequency of technical failures and unreliable stiffness measurements and the intraobserver reproducibility of SWE.

METHODS

This retrospective study was approved by our Institutional Review Board, and informed consent was waived. From August 2011 to January 2013, 540 patients underwent abdominal sonography, including SWE. In 86 patients (group 1), the minimum number of examinations was determined by comparing the intraclass correlation coefficient (ICC) of subsets of the first 2 to 14 measurements with that from 15 measurements. In 454 patients (group 2), 2 SWE sessions were performed in the right lobe within 1 day. Technical failure was defined as when no or little signal was obtained in the elastogram during the first 5 acquisitions; unreliable SWE results were defined as when the interquartile range/median liver stiffness value exceeded 30%. Intraobserver reproducibility was assessed using ICCs and Bland-Altman plots.

RESULTS

In group 1, the ICCs did not significantly increase after the first 6 measurements. In group 2, there were technical failures and unreliable results in 47 patients (10.35%) and 74 patients (16.29%), respectively. In 407 patients, after excluding technical failures, there was no significant difference in the median liver stiffness values between the 2 sessions (6.95 versus 6.86 kPa; P > .05). The overall intraobserver reproducibility was excellent (ICC, 0.95).

CONCLUSIONS

In this study, the optimal minimum number of SWE measurements was 6, and SWE using 6 measurements showed excellent intraobserver reproducibility.

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.

Real-time elastography for assessment of uterine disorders

OBJECTIVES

Sonoelastography is an ultrasound-imaging technique that measures tissue strain. The aim of this study was to define, in a systematic manner, specific sonoelastographic characteristics of the myometrium, fibroids and adenomyosis, to evaluate the feasibility of sonoelastography in patients with suspected gynecological pathology and to compare the results with histology and/or magnetic resonance imaging (MRI)-based diagnoses.

METHODS

We performed a prospective observational cohort study between 2009 and 2011. Two-hundred and eighteen women with suspected gynecological pathology underwent routine transvaginal ultrasound and additional real-time sonographic elastography. Sixty-nine of the 218 women underwent MRI and/or histological examination and were included in the final analysis. Acquisition of elastographic images was standardized. We analyzed the elastographic characteristics of myometrium, fibroids and adenomyosis. An independent observer, unaware of clinical, histological or MRI findings, evaluated the recorded elastographic images and cineloops. These elastographic-based diagnoses were compared with histology and/or MRI diagnoses.

RESULTS

With elastography, the uterus was well delineated from the surrounding bowel. The myometrium was uniform in color in 49% of the cases, with a main color of purple or dark blue, indicating stiffer tissue. Fibroids and adenomyosis had different elastographic characteristics and different color patterns. In general, fibroids were darker and adenomyosis was brighter than adjacent myometrium. The agreement between elastography-based diagnosis of fibroids and adenomyosis with MRI-based diagnosis was excellent; with histology-based diagnosis, agreement was substantial for fibroids and adenomyosis.

CONCLUSIONS

Elastography is able to identify clear discriminating characteristics of the uterus, fibroids and adenomyosis, and elastography-based diagnoses are in excellent agreement with those of MRI. Agreement between elastography-based diagnosis of adenomyosis and histology is substantial but not optimal.

Review article: The prevention and reversal of hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Immunosuppressive treatment of autoimmune hepatitis can prevent or reverse hepatic fibrosis, but these anti-fibrotic effects are inconsistent secondary gains.

AIM

To describe the anti-fibrotic effects of current therapies for autoimmune hepatitis, discuss the pathogenic mechanisms of hepatic fibrosis that might be targeted by anti-fibrotic interventions, indicate the non-invasive diagnostic tests of hepatic fibrosis that must be validated in autoimmune hepatitis and to suggest promising treatment opportunities.

METHODS

Studies cited in PubMed from 1972 to 2013 for autoimmune hepatitis, hepatic fibrosis, cirrhosis, anti-fibrotic therapy and non-invasive tests of hepatic fibrosis were selected.

RESULTS

Hepatic fibrosis improves in 53-57% of corticosteroid-treated patients with autoimmune hepatitis; progressive fibrosis slows or is prevented in 79%; and cirrhosis may be reversed. Progressive hepatic fibrosis is associated with liver inflammation, and the inability to fully suppress inflammatory activity within 12 months is associated with progression to cirrhosis (54%) and death or need for liver transplantation (15%). Liver tissue examination remains the gold standard for assessing hepatic fibrosis, but laboratory and radiological tests may be useful non-invasive methods to measure the fibrotic response. Severe liver inflammation can confound radiological assessments, and the preferred non-invasive test in autoimmune hepatitis is uncertain. Individualised treatment adjustments and adjunctive anti-fibrotic therapies are poised for study in this disease.

CONCLUSIONS

The prevention and reversal of hepatic fibrosis are achievable objectives in autoimmune hepatitis. Strategies that evaluate individualised therapies adjusted to the rapidity and completeness of the inflammatory response, and the use of adjunctive anti-fibrotic interventions, must be evaluated.

Contrast-enhanced CT quantification of the hepatic fractional extracellular space: correlation with diffuse liver disease severity

OBJECTIVE

The purpose of this study was to determine whether contrast-enhanced CT quantification of the hepatic fractional extracellular space (ECS) correlates with the severity of diffuse liver disease.

MATERIALS AND METHODS

The cases of 70 patients without (46 men, 24 women; mean age, 59.1 years) and 36 patients with (23 men, 13 women; mean age, 63.1 years) cirrhosis who had undergone unenhanced and 10-minute delayed phase contrast-enhanced CT were retrospectively identified. By consensus one experienced radiologist and one trainee measured the CT attenuation of the liver and aorta to estimate the fractional ECS, defined as the ratio of the difference between the attenuation of the liver on 10-minute and unenhanced images to the difference between the attenuation of the aorta on 10-minute and unenhanced images multiplied by 1 minus the hematocrit. Findings were correlated with each patient's Model of End-Stage Liver Disease (MELD) score.

RESULTS

The mean MELD score was higher in patients with than in those without cirrhosis (14.3 ± 7.3 versus 7.20 ± 2.4, p < 0.0001). The mean fractional ECS was significantly greater in patients with cirrhosis than in those without cirrhosis (41.0% ± 9.0% versus 23.8% ± 6.3%, p < 0.0001). The fractional ECS correlated with the MELD score (r = 0.572, p < 0.0001) and was predictive of cirrhosis with an area under the receiver operating characteristic curve of 0.953 (p < 0.0001). The sensitivity and specificity of an expanded fractional ECS greater than 30% for the prediction of cirrhosis were 92% and 83%. Multivariate linear regression revealed that the fractional ECS is complementary to the MELD score as a predictor of cirrhosis (p < 0.0001).

CONCLUSION

Noninvasive contrast-enhanced CT quantification of the fractional ECS correlates with the MELD score, an indicator of the severity of liver disease, and merits further study.

Nondiseased liver stiffness measured by shear wave elastography: a pilot study

OBJECTIVES

The purpose of this study was to investigate the value of liver stiffness in patients without liver disease using shear wave elastography and to determine the liver stiffness threshold value for identifying patients with chronic liver diseases.

METHODS

A total of 150 patients who underwent liver sonography coupled with shear wave elastography were enrolled. On the basis of clinical and pathologic criteria, they were assigned to 1 of 2 groups: nondiseased liver (n = 97) and noncirrhotic chronic liver disease (n = 53). Liver stiffness was measured in the right liver, and the median value of 10 measurements was calculated. Both mean and median values in the nondiseased liver group were compared with those in the noncirrhotic chronic liver disease group. To validate this comparison, liver stiffness of the patients who underwent liver biopsy revealing either no fibrosis (fibrosis score F0; n = 5) or substantial fibrosis (F2; n = 14) was also investigated and compared. To determine the optimal threshold value for determining chronic liver disease, a receiver operating characteristic curve analysis was performed.

RESULTS

The mean liver stiffness value in the nondiseased liver group was 5.4 kPa. In the noncirrhotic chronic liver disease group, the mean value was 8.1 kPa. Differences between the nondiseased liver and both noncirrhotic chronic liver disease groups were statistically significant (P < .001). The optimal liver stiffness threshold value for discriminating nondiseased liver from noncirrhotic chronic liver disease was 6.9 kPa. The sensitivity using this threshold was 94%. In the biopsy-proven patients, the mean liver stiffness values were 6.0 kPa in the F0 group and 9.9 kPa in the F2 group.

CONCLUSIONS

The range of liver stiffness in patients with nondiseased liver and the optimal threshold value for discriminating these patients from those with chronic liver disease were identified.

Regression of liver fibrosis is progressive after sustained virological response to HCV therapy in patients with hepatitis C and HIV coinfection

There are few data about the long-term histological outcome of HIV-/HCV-coinfected patients after therapy with interferon and ribavirin. We performed an observational study of 216 patients who received therapy against HCV and who had at least three successive transient elastographies (TE) during the follow-up. The primary endpoint was confirmed fibrosis regression, defined as a reduction of at least 1 point in Metavir fibrosis score, confirmed and without worsening in successive TE. At baseline, 23% had fibrosis stage 4 or cirrhosis. Overall, 82 (38%) achieved sustained virological response (SVR), without differences in baseline fibrosis or time of follow-up. Confirmed fibrosis regression was observed in 55% of patients, higher for SVR (71% vs 44%; P < 0.01), and the likelihood of achieving fibrosis regression at 3, 5 and 7 years was 0.17, 0.51 and 0.67, respectively, for SVR patients, in comparison with 0.02, 0.23 and 0.41 for no SVR patients (P < 0.01, log-rank test at any time point). Progressive regression, defined as continuous improvement in successive TE, was observed in 62% of patients with advanced liver fibrosis or cirrhosis who achieved SVR. In a Cox regression model, only SVR (HR, 4.01; 95% CI, 2.33-7.57; P < 0.01) and a younger age (HR, 1.14; 95% CI, 1.05-1.25; P < 0.01; per year) were associated with fibrosis regression. This study confirms that the rate of liver fibrosis regression increases during the follow-up after SVR to interferon therapy in HIV-/HCV-coinfected patients.

Correlates of nonalcoholic fatty liver among women receiving residential mental health care

PURPOSE

To review the risk factors for diagnosis of nonalcoholic fatty liver disease (NAFLD) in women in a mental health, dual diagnosis, treatment facility.

DATA SOURCES

A review of the literature and retrospective chart reviews of patients to identify factors within this population of women most closely associated with diagnosis of NAFLD.

CONCLUSIONS

NAFLD is a common diagnosis and as obesity rates increase in the United States the incidence for this disease is also increasing. Identifiable risk factors are associated with the presence of this disease. Advanced practice nurses, as prescribers, need to be aware that the presence of NAFLD may interfere with drug metabolism and toxin elimination in their patients.

IMPLICATIONS FOR PRACTICE

Numerous physical conditions, behavioral symptoms, and laboratory findings are identified as associated conditions of NAFLD. Patients seen in primary care practices have NAFLD, but patients in treatment centers for mental health disorders are also affected. This population is particularly at risk because of the hepatotoxic effects of many medications used in psychiatric-mental health settings.

HIV/hepatitis C virus-coinfected patients and cirrhosis: how to diagnose it and what to do next?

Liver disease, specifically cirrhosis, is a leading cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients. The diagnosis of early cirrhosis in HIV/hepatitis C virus (HCV)-coinfected patients may be challenging. The development of noninvasive methods for fibrosis assessment empowers the infectious disease specialist to diagnose advanced fibrosis or cirrhosis. Early diagnosis is essential to enroll patients in screening programs for esophageal varices and hepatocellular carcinoma. Cirrhosis may also modify decisions about treatment of both HIV and HCV, including vaccination, medications chosen, and referral for liver transplant.

Tissue Doppler imaging and tissue strain imaging for the evaluation of hepatic fibrosis in patients with chronic hepatitis B

We studied the feasibility of evaluating the stages of liver fibrosis with tissue Doppler imaging (TDI) and tissue strain imaging (TSI) for patients with chronic hepatitis B virus infection. One hundred ten patients were divided into two groups: normal adult group (n = 38) and chronic liver disease group (n = 72, patients infected with HBVs). The chronic liver disease group was divided into three subgroups on the basis of the Scheuer scoring system and clinical evidence: mild fibrosis (S0 and S1, n = 11), moderate fibrosis (S2 and S3, n = 27) and cirrhosis (S4 and clinically typical cirrhosis, n = 34) groups. TDI was performed for a chosen oblique section. Four regions of interest (ROIs), A-D, were chosen in the hepatic parenchyma based on the direction of propagation from the heart to the liver. Strain rate curves were obtained on the basis of TDI and TSI findings. Strain peak rates (SPRs) of all ROIs and the differences in times to SPRs for the four ROIs (TA-B, TB-C and TC-D) in the hepatic parenchyma were measured with TDI and TSI. Strain rate curves were analyzed for each ROI. The strain rate curves for the normal adult group were synchronous, whereas those for the chronic liver disease group were asynchronous. SPRs of the ROIs gradually decreased with the progression of liver fibrosis. The SPRs of ROI B significantly correlated with chronic liver disease severity (r = 0.991, p < 0.05). Areas under the curve (AUCs) of the ROI A and ROI B SPRs at the moderate fibrosis and cirrhosis stages were 0.86 ± 0.06, 0.81 ± 0.56 and 0.90 ± 0.65, 0.92 ± 0.04, respectively. The AUC of the SPRs of ROIs A and B correlated better than the platelet/age/phosphatase/α-fetoprotein/aspartate aminotransferase (PAPAS) index for advanced fibrosis. The differences in time to SPRs among the peaks of the four ROIs (TA-B, TB-C and TC-D) gradually increased with the progression of liver fibrosis. TDI and TSI with quantitative measurements using tissue Doppler analysis software (TDIQ, GE Medical Systems, Horten, Norway) provided reliable information for evaluating non-invasive liver fibrosis in patients with chronic hepatitis B.

Ultrasound elastography for fibrosis surveillance is cost effective in patients with chronic hepatitis C virus in the UK

BACKGROUND

Chronic hepatitis C (HCV) is a significant risk factor for cirrhosis and subsequently hepatocellular carcinoma (HCC). HCV patients with cirrhosis are screened for HCC every 6 months. Surveillance for progression to cirrhosis and consequently access to HCC screening is not standardized. Liver biopsy, the usual test to determine cirrhosis, carries a significant risk of morbidity and associated mortality. Transient ultrasound elastography (fibroscan) is a non-invasive test for cirrhosis.

PURPOSE

This study assesses the cost effectiveness of annual surveillance for cirrhosis in patients with chronic HCV and the effect of replacing biopsy with fibroscan to diagnose cirrhosis.

METHOD

A Markov decision analytic model simulated a hypothetical cohort of 10,000 patients with chronic HCV initially without fibrosis over their lifetime. The cirrhosis surveillance strategies assessed were: no surveillance; current practice; fibroscan in current practice with biopsy to confirm cirrhosis; fibroscan completely replacing biopsy in current practice (definitive); annual biopsy; annual fibroscan with biopsy to confirm cirrhosis; annual definitive fibroscan.

RESULTS

Our results demonstrate that annual definitive fibroscan is the optimal strategy to diagnose cirrhosis. In our study, it diagnosed 20 % more cirrhosis cases than the current strategy, with 549 extra patients per 10,000 accessing screening over a lifetime and, consequently, 76 additional HCC cases diagnosed. The lifetime cost is £98.78 extra per patient compared to the current strategy for 1.72 additional unadjusted life years. Annual fibroscan surveillance of 132 patients results in the diagnosis one additional HCC case over a lifetime. The incremental cost-effectiveness ratio for an annual definitive fibroscan is £6,557.06/quality-adjusted life years gained.

CONCLUSION

Annual definitive fibroscan may be a cost-effective surveillance strategy to identify cirrhosis in patients with chronic HCV, thereby allowing access of these patients to HCC screening.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

The role of transient elastography in the detection of liver disease in patients with chronic pancreatitis

BACKGROUND & AIMS

Quantification of liver stiffness with transient elastography (TE) is validated for staging hepatic fibrosis in chronic hepatitis C infection. The current study was aimed to assess the diagnostic performance of liver stiffness measurement for the determination of fibrosis stage in patients with chronic pancreatitis.

METHODS

Thirty consecutive patients with chronic pancreatitis and increased liver enzyme were enrolled over a 2.5-year period. Eight liver living donor candidates were recruited to serve as internal controls. The TE values were compared with non-invasive fibrosis scoring systems including aspartate transaminase (AST)/alanine aminotransferase (ALT) ratio, APRI, non-alcoholic fatty liver disease NAFLD score, FIB-4 index and to liver histology.

RESULTS

TE was successful in all patients. Stiffness values ranged from 3.1 to 69 kPa (mean 16.9). Liver stiffness was correlated with fibrosis stage (Spearman's correlation 0.73, P < 0.0001). Areas under receiver operator characteristics curves for fibrosis F = 4 were 0.92 for TE, 0.87 for FIB-4 index, 0.81 for APRI, 0.73 for NAFLD score and 0.71 for AST/ALT ratio. Optimal stiffness cut-off values for diagnosis fibrosis F = 4 was 10.9 kPa, with 90% sensitivity, 85% specificity and 86% accuracy.

CONCLUSION

Our study provides for the first time evidence that liver stiffness in patients with chronic pancreatitis and concomitant cholestasis can be measured by TE.

Factors influencing reliability of liver stiffness measurements using transient elastography (M-probe)-monocentric experience

AIM

To retrospectively assess the feasibility of transient elastography (TE) and the factors associated with failed and unreliable liver stiffness measurements (LSMs), in patients with chronic liver diseases.

MATERIAL AND METHODS

Our retrospective study included 8218 consecutive adult patients with suspected chronic liver diseases. In each patient, LSMs were performed with a FibroScan(®) device (Echosens, France), with the M probe. Failure of TE measurements was defined if no valid measurement was obtained after at least 10 shots and unreliable if fewer than 10 valid shots were obtained, success rate (SR) <60% and/or interquartile range interval/median value (IQR/Med) ≥30%.

RESULTS

From the 8218 patients, failed and unreliable LSMs were observed in 29.2% of cases. In univariant analysis, the following risk factors were associated with failed and unreliable measurements: age over 50 years (OR 2.04; 95%CI 1.84-2.26), female gender (OR 1.32; 95%CI 1.20-1.45), BMI>27.7kg/m(2) (OR 2.89, 95%CI 2.62-3.19), weight>77kg (OR 2.17; 95%CI 1.97-2.40) and height<162cm (OR 1.26; 95%CI 1.14-1.40). In multivariate analysis all the factors mentioned above were independently associated with the risk of failed and unreliable measurements. If all the negative predictive factors were present (woman, older than 50 years, with BMI>27.7kg/m(2), heavier than 77kg and shorter than 162cm), the rate of failed and unreliable measurements was 58.5%. In obese patients (BMI≥30kg/m(2)), the rate of failed and unreliable measurements was 49.5%.

CONCLUSION

Failed and unreliable LSMs were observed in 29.1% of patients. Female gender, older age, higher BMI, higher weight and smaller height were significantly associated with failed and unreliable LSMs.

Acoustic waves in medical imaging and diagnostics

Up until about two decades ago acoustic imaging and ultrasound imaging were synonymous. The term ultrasonography, or its abbreviated version sonography, meant an imaging modality based on the use of ultrasonic compressional bulk waves. Beginning in the 1990s, there started to emerge numerous acoustic imaging modalities based on the use of a different mode of acoustic wave: shear waves. Imaging with these waves was shown to provide very useful and very different information about the biological tissue being examined. We discuss the physical basis for the differences between these two basic modes of acoustic waves used in medical imaging and analyze the advantages associated with shear acoustic imaging. A comprehensive analysis of the range of acoustic wavelengths, velocities and frequencies that have been used in different imaging applications is presented. We discuss the potential for future shear wave imaging applications.

Ultrasound elastography in liver

Conventional imaging techniques cannot provide information about tissue mechanical properties. Many injuries can cause changes in tissue stiffness, especially tumors and fibrosis. In recent years, various non-invasive ultrasound methods have been developed to study tissue elasticity for a large number of applications (breast, thyroid, prostate, kidneys, blood vessels, liver…). For non-invasive assessment of liver diseases, several ultrasound elastography techniques have been investigated: Transient elastography (the most extensively used), Real Time Elastography (RTE), Acoustic Radiation Force Impulse Imaging (ARFI) and more recently Shear Wave Elastography (SWE). Even if evaluation of liver fibrosis in chronic liver disease remains the principal application, there are many others applications for liver: predicting cirrhosis-related complications; monitoring antiviral treatments in chronic viral liver disease; characterizing liver tumors; monitoring local treatments, etc. The aim of this article is to report on the different hepatic ultrasound elastography techniques, their advantages and disadvantages, their diagnostic accuracy, their applications in clinical practice.

Acoustic radiation force impulse imaging for non-invasive assessment of liver fibrosis in chronic hepatitis B

Acoustic radiation force impulse (ARFI) imaging is a novel ultrasound-based elastography method that is integrated in a conventional ultrasound machine. It might provide an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. While previous studies have shown comparable diagnostic accuracy of ARFI to transient elastography in chronic hepatitis C, the aim of the present prospective multicenter study was to evaluate ARFI for the assessment of liver fibrosis in chronic hepatitis B. ARFI imaging involves the mechanical excitation of tissue using short-duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear-wave propagation which is tracked using ultrasonic, correlation-based methods and recorded in m/s. In the present international prospective study, patients infected with chronic hepatitis B received ARFI imaging, blood tests and if available transient elastography. The results were compared to liver biopsy as reference method analysed by a central pathologist. In 92 of 114 patients, a comparison of ARFI with transient elastography was possible. ARFI imaging and transient elastography correlated significantly with histological fibrosis stage. The diagnostic accuracy expressed as areas under ROC curves for ARFI imaging and transient elastography was 0.75 and 0.83 for the diagnosis of significant fibrosis (F ≥ 2), 0.93 and 0.94 for the diagnosis of severe fibrosis (F ≥ 3), and 0.97 and 0.93 for the diagnosis of liver cirrhosis, respectively. No significant difference was found between ARFI and transient elastography. ARFI imaging is a reliable ultrasound-based method for the assessment of advanced stages of liver fibrosis in chronic hepatitis B.

Clinical application of liver stiffness measurement using transient elastography in chronic liver disease from longitudinal perspectives

Accurate determination of the presence and degree of fibrosis in liver is of great importance, because the prognosis and management strategies for chronic liver disease depend mainly on these factors. To date, liver biopsy (LB) remains the "gold standard" for assessing the severity of liver fibrosis; however, LB is often limited by its invasiveness, sampling error, and intra/inter-observer variability in histological interpretation. Furthermore, repeated LB examinations within a short time interval are indeed ineligible in a real clinical practice. Thus, due to the pressing need for non-invasive surrogates for liver fibrosis, transient elastography (TE), as a novel ultrasound based technology, has allowed a noninvasive measurement of liver stiffness and has gained in popularity over recent years. In the past few years, additional roles for transient TE beyond the initial purpose of a non-invasive surrogate for LB have included the prediction of the most two critical consequences of fibrosis progression: the development of portal hypertension-related complications and hepatocellular carcinoma. This indicates that the role of transient TE is not merely limited to reducing the need for LB, but transient TE can enable the establishment of tailored management strategies by providing more detailed prognostic information. In particular, under the concept in which the clinical course of liver fibrosis is dynamic and bidirectional, especially when appropriate intervention is commenced, transient TE can be used to track the dynamic changes in fibrotic burden during antiviral or antifibrotic treatment. This review discussed extended applications of transient TE in prediction of the development of real clinical endpoints from a longitudinal perspective.

Determination of reliability criteria for liver stiffness evaluation by transient elastography

Liver stiffness evaluation (LSE) is usually considered as reliable when it fulfills all the following criteria: ≥10 valid measurements, ≥60% success rate, and interquartile range / median ratio (IQR/M) ≤0.30. However, such reliable LSE have never been shown to be more accurate than unreliable LSE. Thus, we aimed to evaluate the relevance of the usual definition for LSE reliability, and to improve reliability by using diagnostic accuracy as a primary outcome in a large population. 1,165 patients with chronic liver disease from 19 French centers were included. All patients had liver biopsy and LSE. 75.7% of LSE were reliable according to the usual definition. However, these reliable LSE were not significantly more accurate than unreliable LSE with, respectively: 85.8% versus 81.5% well-classified patients for the diagnosis of cirrhosis (P = 0.082). In multivariate analyses with different diagnostic targets, LSE median and IQR/M were independent predictors of fibrosis staging, with no significant influence of ≥10 valid measurements or LSE success rate. These two reliability criteria determined three LSE groups: "very reliable" (IQR/M ≤0.10), "reliable" (0.10< IQR/M ≤0.30, or IQR/M >0.30 with LSE median <7.1 kPa), and "poorly reliable" (IQR/M >0.30 with LSE median ≥7.1 kPa). The rates of well-classified patients for the diagnosis of cirrhosis were, respectively: 90.4%, 85.8%, and 69.5% (P < 10(-3) ). According to these new reliability criteria, 9.1% of LSE were poorly reliable (versus 24.3% unreliable LSE with the usual definition, P < 10(-3) ), 74.3% were reliable, and 16.6% were very reliable.

CONCLUSION

The usual definition for LSE reliability is not relevant. LSE reliability depends on IQR/M according to liver stiffness median level, defining thus three reliability categories: very reliable, reliable, and poorly reliable LSE. (HEPATOLOGY 2013).

Staging of hepatic fibrosis: comparison of magnetic resonance elastography and shear wave elastography in the same individuals

Objective

To cross-validate liver stiffness (LS) measured on shear wave elastography (SWE) and on magnetic resonance elastography (MRE) in the same individuals.

Materials and Methods

We included 94 liver transplantation (LT) recipients and 114 liver donors who underwent either MRE or SWE before surgery or biopsy. We determined the technical success rates and the incidence of unreliable LS measurements (LSM) of SWE and MRE. Among the 69 patients who underwent both MRE and SWE, the median and coefficient of variation (CV) of the LSM from each examination were compared and correlated. Areas under the receiver operating characteristic curve in both examinations were calculated in order to exclude the presence of hepatic fibrosis (HF).

Results

The technical success rates of MRE and SWE were 96.4% and 92.2%, respectively (p = 0.17), and all of the technical failures occurred in LT recipients. SWE showed 13.1% unreliable LSM, whereas MRE showed no such case (p < 0.05). There was moderate correlation in the LSM in both examinations (r = 0.67). SWE showed a significantly larger median LSM and CV than MRE. Both examinations showed similar diagnostic performance for excluding HF (Az; 0.989, 1.000, respectively).

Conclusion

MRE and SWE show moderate correlation in their LSMs, although SWE shows higher incidence of unreliable LSMs in cirrhotic liver.

Non-invasive measurement of liver and pancreas fibrosis in patients with cystic fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) have a relevant morbidity and mortality caused by CF-related liver-disease. While transient elastography (TE) is an established elastography method in hepatology centers, Acoustic-Radiation-Force-Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method which is integrated in a conventional ultrasound-system. The aim of the present study was to evaluate the prevalence of liver-fibrosis in patients with CF using TE, ARFI-imaging and fibrosis blood tests.

METHODS

106 patients with CF were prospectively included in the present study and received ARFI-imaging of the left and right liver-lobe, ARFI of the pancreas TE of the liver and laboratory evaluation.

RESULTS

The prevalence of liver-fibrosis according to recently published best practice guidelines for CFLD was 22.6%. Prevalence of significant liver-fibrosis assessed by TE, ARFI-right-liver-lobe, ARFI-left-liver-lobe, Fibrotest, Fibrotest-corrected-by-haptoglobin was 17%, 24%, 40%, 7%, and 16%, respectively. The best agreement was found for TE, ARFI-right-liver-lobe and Fibrotest-corrected-by-haptoglobin. Patients with pancreatic-insufficiency had significantly lower pancreas-ARFI-values as compared to patients without.

CONCLUSIONS

ARFI-imaging and TE seem to be promising non-invasive methods for detection of liver-fibrosis in patients with CF.

Performance of liver stiffness measurements by transient elastography in chronic hepatitis

AIM

To compare results of liver stiffness measurements by transient elastography (TE) obtained in our patients population with that used in a recently published meta-analysis.

METHODS

This was a single center cross-sectional study. Consecutive patients with chronic viral hepatitis scheduled for liver biopsy at the outpatient ward of our Infectious Diseases Department were enrolled. TE was carried out by using FibroScan™ (Echosens, Paris, France). Liver biopsy was performed on the same day as TE, as day case procedure. Fibrosis was staged according to the Metavir scoring system. The diagnostic performance of TE was assessed by using receiver operating characteristic (ROC) curves and the area under the ROC curve analysis.

RESULTS

Two hundred and fifty-two patients met the inclusion criteria. Six (2%) patients were excluded due to unreliable TE measurements. Thus, 246 (171 men and 75 women) patients were analyzed. One hundred and ninety-five (79.3%) patients had chronic hepatitis C, 41 (16.7%) had chronic hepatitis B, and 10 (4.0%) were coinfected with human immunodeficiency virus. ROC curve analysis identified optimal cut-off value of TE as high as 6.9 kPa for F ≥ 2; 7.9 kPa for F ≥ 3; 9.6 kPa for F = 4 in all patients (n = 246), and as high as 6.9 kPa for F ≥ 2; 7.3 kPa for F ≥ 3; 9.3 kPa for F = 4 in patients with hepatitis C (n = 195). Cut-off values of TE obtained by maximizing only the specificity were as high as 6.9 kPa for F ≥ 2; 9.6 kPa for F ≥ 3; 12.2 kPa for F = 4 in all patients (n = 246), and as high as 7.0 kPa for F ≥ 2; 9.3 kPa for F ≥ 3; 12.3 kPa for F = 4 in patients with hepatitis C (n = 195).

CONCLUSION

The cut-off values of TE obtained in this single center study are comparable to that obtained in a recently published meta-analysis that included up to 40 studies.

Non-invasive methods for the assessment of hepatic fibrosis: transient elastography, hyaluronic acid, 13C-aminopyrine breath test and cytokeratin 18 fragment

BACKGROUND. In the management of chronic hepatitis C (CHC) patients, liver biopsy is the gold standard for liver fibrosis assessment despite some technical limits and risks. Non-invasive approaches have been proposed as alternative methods to evaluate structural liver damage. AIM. To investigate the diagnostic accuracy of transient elastography, 13C-aminopyrine breath test (13C-ABT), serum hyaluronic acid (HA) and cytokeratin 18 Asp396 fragment (CK-18) as non-invasive methods of liver fibrosis assessment ad their correlation to METAVIR score. MATERIAL AND METHODS. In a cohort of 57 CHC patients, liver stiffness, cumulative percentage of administered dose of 13C-aminopyrine at 120 min, serum HA and serum CK-18 concentration were determined. Diagnostic accuracy in detecting significant fibrosis (F ≥ 2), severe fibrosis (F ≥ 3) and cirrhosis (F = 4) was assessed by the area under the receiver operating characteristic curve. RESULTS. Liver fibrosis score showed a strong correlation with liver stiffness (r = 0.667; p < 0.0001) and a significant inverse correlation with 13C-ABT results (r = -0.418; p = 0.0012). A weaker correlation was found with CK18 (r = 0.329; p = 0.0126) and no correlation with HA. Areas under the curve of elastography, 13C-ABT, HA and CK18 were: 0.98, 0.75, 0.69, 0.64, respectively, for F ≥ 2; 0.97, 0.69, 0.80, 0.66, respectively, for F ≥ 3; 0.95, 0.64, 0.70, 0.56, respectively, for F = 4. CONCLUSION. Elastography has the best diagnostic accuracy for the assessment of the degree of liver fibrosis in CHC patients. Its application can provide an alternative useful tool for monitoring the disease evolution.

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core: Canadian guidelines for management and treatment of HIV/hepatitis C coinfection in adults

BACKGROUND

Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV, and is responsible for a heavy burden of morbidity and mortality. HIV-HCV management is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens.

OBJECTIVE

To develop national standards for the management of HCV-HIV coinfected adults in the Canadian context.

METHODS

A panel with specific clinical expertise in HIV-HCV co-infection was convened by The CIHR HIV Trials Network to review current literature, existing guidelines and protocols. Following broad solicitation for input, consensus recommendations were approved by the working group, and were characterized using a Class (benefit verses harm) and Level (strength of certainty) quality-of-evidence scale.

RESULTS

All HIV-HCV coinfected individuals should be assessed for HCV therapy. Individuals unable to initiate HCV therapy should initiate antiretroviral therapy to slow liver disease progression. Standard of care for genotype 1 is pegylated interferon and weight-based ribavirin dosing plus an HCV protease inhibitor; traditional dual therapy for 24 weeks (for genotype 2/3 with virological clearance at week 4); or 48 weeks (for genotypes 2-6). Therapy deferral for individuals with mild liver disease may be considered. HIV should not be considered a barrier to liver transplantation in coinfected patients.

DISCUSSION

Recommendations may not supersede individual clinical judgement.

Liver stiffness measurement in cirrhotic patient -- implications of disease activity and treatment efficacy

Liver stiffness measurement (LSM) is a noninvasive method for the diagnosis of hepatic fibrosis. The aim of this study was to evaluate the effects of hepatitis activity and antiviral therapy on LSM in cirrhotic patients. Consecutive patients with compensated hepatic cirrhosis were enrolled for LSM. The medical records of hepatitis activity and antiviral therapy before enrollment were reviewed. Patients were stratified into inactive, fluctuating, and active groups by serial change of alanine transaminase level. For chronic hepatitis C, patients were stratified into sustained virological response (SVR) and non-SVR (NSVR) by effect of antiviral treatment. LSM results were compared among different groups. A total of 163 patients (mean age = 57.2 ± 11.0 years) were enrolled. The median (range) LSM values were 9.6 (4.2-20.6), 10.25 (3.9-49.6), and 15.75 (4.8-61.5) kPa in the inactive, fluctuating, and active groups, respectively. Patients in the active group had significantly higher LSM values. For chronic hepatitis C, median (range) LSM values were 16.6 (8.1-61.5), 22.9 (11.1-37.4), and 11.2 (3.9-27.0) kPa in patients without antiviral therapy, in NSVR, and in SVR groups, respectively. Patients with SVR had significantly lower LSM values. For chronic hepatitis B, median (range) LSM values were 11.8 (5.1-46.6), 16.85 (4.2-48), and 10.6 (4.3-46.4 kPa) kPa in patients without oral nucleos(t)ide analogue (NA) therapy, with NA < 12, and ≧12 months, respectively. There was a significantly lower LSM value in patients with NA therapy≧12 months. There were low LSM values in cirrhotic patients without hepatitis activity, as well as with SVR in chronic hepatitis C and long-term NA therapy in chronic hepatitis B.

Coinfection by human immunodeficiency virus and hepatitis C virus: noninvasive assessment and staging of fibrosis

PURPOSE OF REVIEW

This review presents recent findings on noninvasive alternatives for the diagnosis of fibrosis and cirrhosis in patients who are coinfected with HIV and hepatitis C virus (HCV).

RECENT FINDINGS

APRI, FIB-4, and Forns were accurate indices for the diagnosis of cirrhosis [area under the receiver operating characteristic curve (AUROC) >0.80] but not for the diagnosis of significant and advanced fibrosis (AUROC < 0.80). Diagnostic accuracy was affected by CD4 T-cell count and alanine aminotransferase levels. An artificial neural network to predict significant fibrosis was highly accurate (AUROC of 0.853), outperforming simple noninvasive indices. Derivations of the FibroMeter panel (FibroMeter HICV and FibroMeter HICV) achieved high diagnostic accuracy for significant fibrosis (AUROC of 0.823 and 0.833, respectively). Transient elastography had higher predictive accuracy than previously validated panels for diagnosis of advanced fibrosis (F ≥ 3) and cirrhosis (0.93 and 0.99, respectively). However, misclassification as F ≥ 3 was more common among patients with steatosis than among those without steatosis (25 versus 5%, P = 0.01). Moreover, transient elastography can predict clinically significant and severe portal hypertension in HIV/HCV-coinfected patients.

SUMMARY

Both biomarkers and transient elastography can accurately diagnose fibrosis and cirrhosis and are better at excluding than at predicting liver disease in HIV/HCV-coinfected patients.

Accuracy of real-time shear wave elastography for assessing liver fibrosis in chronic hepatitis C: a pilot study

Real-time shear wave elastography (SWE) is a novel, noninvasive method to assess liver fibrosis by measuring liver stiffness. This single-center study was conducted to assess the accuracy of SWE in patients with chronic hepatitis C (CHC), in comparison with transient elastography (TE), by using liver biopsy (LB) as the reference standard. Consecutive patients with CHC scheduled for LB by referring physicians were studied. One hundred and twenty-one patients met inclusion criteria. On the same day, real-time SWE using the ultrasound (US) system, Aixplorer (SuperSonic Imagine S.A., Aix-en-Provence, France), TE using FibroScan (Echosens, Paris, France), and US-assisted LB were consecutively performed. Fibrosis was staged according to the METAVIR scoring system. Analyses of receiver operating characteristic (ROC) curve were performed to calculate optimal area under the ROC curve (AUROC) for F0-F1 versus F2-F4, F0- F2 versus F3-F4, and F0-F3 versus F4 for both real-time SWE and TE. Liver stiffness values increased in parallel with degree of liver fibrosis, both with SWE and TE. AUROCs were 0.92 (95% confidence interval [CI]: 0.85-0.96) for SWE and 0.84 (95% CI: 0.76-0.90) for TE (P = 0.002), 0.98 (95% CI: 0.94-1.00) for SWE and 0.96 (95% CI: 0.90-0.99) for TE (P = 0.14), and 0.98 (95% CI: 0.93-1.00) for SWE and 0.96 (95% CI: 0.91-0.99) for TE (P = 0.48), when comparing F0-F1 versus F2- F4, F0- F2 versus F3-F4, and F0 -F3 versus F4, respectively.

CONCLUSION

The results of this study show that real-time SWE is more accurate than TE in assessing significant fibrosis (≥ F2). With respect to TE, SWE has the advantage of imaging liver stiffness in real time while guided by a B-mode image. Thus, the region of measurement can be guided with both anatomical and tissue stiffness information.

Hepatic fibrosis: evaluation with semiquantitative contrast-enhanced CT

PURPOSE

To evaluate the feasibility of using contrast material-enhanced computed tomographic (CT) measurements of hepatic fractional extracellular space (fECS) and macromolecular contrast material (MMCM) uptake to measure severity of liver fibrosis.

MATERIALS AND METHODS

All procedures were approved by and executed in accordance with University of California, San Francisco, institutional animal care and use committee regulations. Twenty-one rats that received intragastric CCl(4) for 0-12 weeks were imaged with respiratory-gated micro-CT by using both a conventional contrast material and a novel iodinated MMCM. Histopathologic hepatic fibrosis was graded qualitatively by using the Ishak fibrosis score and quantitatively by using morphometry of the fibrosis area. Hepatic fECS and MMCM uptake were calculated for each examination and correlated with histopathologic findings by using uni- and multivariate linear regressions.

RESULTS

Ishak fibrosis scores ranged from a baseline of 0 in untreated animals to a maximum of 5. Histopathologic liver fibrosis area increased from 0.46% to 3.5% over the same interval. Strong correlations were seen between conventional contrast-enhanced CT measurements of fECS and both the Ishak fibrosis scores (R(2) = 0.751, P < .001) and the fibrosis area (R(2) = 0.801, P < .001). Strong negative correlations were observed between uptake of MMCM in the liver and Ishak fibrosis scores (R(2) = 0.827, P < .001), as well as between uptake of MMCM in the liver and fibrosis area (R(2) = 0.643, P = .001). Multivariate linear regression analysis showed a trend toward independence for fECS and MMCM uptake in the prediction of Ishak fibrosis scores, with an R(2) value of 0.86 (P = .081 and P = .033, respectively).

CONCLUSION

Contrast-enhanced CT measurements of fECS and MMCM uptake are individually capable of being used to estimate the degree of early hepatic fibrosis in a rat model.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112452/-/DC1.

Non-invasive evaluation of hepatic manifestation in Wilson disease with transient elastography, ARFI, and different fibrosis scores

OBJECTIVE

Noninvasive investigation of liver fibrosis with ultrasound-based elastography and laboratory-based fibrosis indices have been established in various chronic liver diseases within the last years. We aimed to evaluate feasibility and diagnostic value of transient elastography (TE), acoustic radiation force impulse imaging (ARFI), and different serologic fibrosis indices in Wilson's disease (WD).

MATERIALS AND METHODS

TE and ARFI were performed in 50 Wilson patients. In addition, AST/Platelet Ratio Index (APRI), FIB-4, and Forns score were calculated. Hepatic fibrosis was classified by a clinical score.

RESULTS

Of the 50 Wilson patients 41 had hepatic manifestation of WD. TE results were significantly increased in advanced hepatic fibrosis (7.0 ± 2.2 kPa; p < 0.05) and cirrhosis (10.1 ± 6.73 kPa; p < 0.05) compared to individuals without hepatic manifestation (5.0 ± 1.4 kPa). Right liver lobe ARFI (R-ARFI) values were only increased in cirrhotic patients (1.43 ± 0.28 vs. 1.19 ± 0.14 m/s; p < 0.05). The cutoff values to best discriminate cirrhosis were 6.1 kPa for TE and 1.29 m/s for R-ARFI. Left lobe ARFI failed to provide additional diagnostic benefit. Elastography methods displayed a significant correlation with APRI, FIB-4, and Forns indices (Pearson's rho > 0.33; p < 0.03).

CONCLUSIONS

TE displayed a gradual increase between different stages of hepatic manifestation in WD and could significantly discriminate cirrhosis. The TE cutoff for cirrhosis may be clinically more relevant than the R-ARFI value.

Review of MR elastography applications and recent developments

The technique of MR elastography (MRE) has emerged as a useful modality for quantitatively imaging the mechanical properties of soft tissues in vivo. Recently, MRE has been introduced as a clinical tool for evaluating chronic liver disease, but many other potential applications are being explored. These applications include measuring tissue changes associated with diseases of the liver, breast, brain, heart, and skeletal muscle including both focal lesions (e.g., hepatic, breast, and brain tumors) and diffuse diseases (e.g., fibrosis and multiple sclerosis). The purpose of this review article is to summarize some of the recent developments of MRE and to highlight some emerging applications.

Performance of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B: a meta-analysis

BACKGROUND

Transient elastography (TE), a non-invasive tool that measures liver stiffness, has been evaluated in meta-analyses for effectiveness in assessing liver fibrosis in European populations with chronic hepatitis C (CHC). However, these data cannot be extrapolated to populations in Asian countries, where chronic hepatitis B (CHB) is more prevalent. In this study, we performed a meta-analysis to assess the overall performance of TE for assessing liver fibrosis in patients with CHB.

METHODS

Studies from the literature and international conference abstracts which enrolled only patients with CHB or performed a subgroup analysis of such patients were enrolled. Combined effects were calculated using area under the receiver operating characteristic curves (AUROC) and diagnostic accuracy values of each study.

RESULT

A total of 18 studies comprising 2,772 patients were analyzed. The mean AUROCs for the diagnosis of significant fibrosis (F2), severe fibrosis (F3), and cirrhosis (F4) were 0.859 (95% confidence interval [CI], 0.857-0.860), 0.887 (95% CI, 0.886-0.887), and 0.929 (95% CI, 0.928-0.929), respectively. The estimated cutoff for F2 was 7.9 (range, 6.1-11.8) kPa, with a sensitivity of 74.3% and specificity of 78.3%. For F3, the cutoff value was determined to be 8.8 (range, 8.1-9.7) kPa, with a sensitivity of 74.0% and specificity of 63.8%. The cutoff value for F4 was 11.7 (range, 7.3-17.5) kPa, with a sensitivity of 84.6% and specificity of 81.5%.

CONCLUSION

TE can be performed with good diagnostic accuracy for quantifying liver fibrosis in patients with CHB.

Developing a 'traffic light' test with potential for rational early diagnosis of liver fibrosis and cirrhosis in the community

BACKGROUND

Liver disease develops silently and presents late, with often fatal complications.

AIM

To develop a 'traffic light' test for liver disease suitable for community use that could enhance assessment of liver risk and allow rational referral of more severe disease to specialist care.

DESIGN AND SETTING

Two cohorts from Southampton University Hospital Trust Liver Unit: model development and a validation cohort to evaluate prognosis.

METHOD

A total of 1038 consecutive liver patients (inpatient and outpatient) (development n = 397, validation n = 641) for whom the relevant blood tests had been performed, were followed for a mean of 46 months (range 13-89 months). Blood tests for: hyaluronic acid (HA), procollagen-3 N-terminal peptide (P3NP), and platelet count were combined in a diagnostic algorithm to stage liver disease.

RESULTS

A simple clinical rule combined: HA, P3NP, and platelet count into a 'traffic light' algorithm, grading the results red--high risk, amber--intermediate risk, and green--low risk. In the validation cohort, no green subjects died or developed varices or ascites (n = 202); in the amber group, 9/267 (3.3%) died, 0/267 developed varices, and 2/267 (0.7%) developed ascites; in the red group, 24/172 died (14%), 24/172 (14%) developed varices, and 20/172 developed (11.6%) ascites. Survival was reduced in red (P<0.001) and amber (P<0.012) groups compared with green.

CONCLUSION

A simple blood test triages liver disease into three prognostic groups; used in the community, it could enhance the management of risk factors in primary care and rationalise secondary care referrals, including the many patients with fatty liver and relatively minor elevations in alanine transaminase.

Management of hepatitis C in HIV and/or HBV co-infected patients

Co-infection with either HIV or HBV in chronic hepatitis C patients is common, since all these viruses share transmission routes and geographical distribution. Interaction between these viruses generally amplifies liver damage, increasing the risk of developing end-stage liver disease and hepatocellular carcinoma. HIV-HCV co-infection is associated with poorer response to antiviral therapy. New antivirals against HCV are eagerly awaited for this population. HBV-HCV dual infections are less common. The principles guiding indication of therapy in monoinfected patients should be followed considering which virus replicates in persons with serological markers of dual HBV-HCV infection. Although there is growing evidence supporting the use of direct acting antivirals (DAA) in dually infected patients with active HCV replication, prospective trials should be conducted to demonstrate their benefit, assessing carefully the rate and clinical consequences of HBV rebounds.

Transient elastography and simple blood markers in the diagnosis of esophageal varices for compensated patients with hepatitis B virus-related cirrhosis

BACKGROUND AND AIM

Transient elastography (TE) has been useful in esophageal varices (EV) diagnosis for chronic hepatitis C patients. In the present study, we evaluate the usefulness of TE and simple blood markers in the EV diagnosis of patients with hepatitis B virus (HBV)-related cirrhosis, prospectively.

METHODS

Consecutive patients with compensated cirrhosis and positive HBV surface antigen were enrolled, prospectively. At enrollment, the aspartate aminotransferase (AST) to alanine aminotransferase ratio (AAR) and the AST to platelet ratio index (APRI) were recorded, and TE was performed. Two experienced endoscopists assessed EV independently. High-risk EV was defined as small size with a red color sign, and medium or large in size. The diagnostic performances, optimal cut-offs, and the validities of TE, APRI, platelet count (PLT), and AAR in EV diagnosis were assessed.

RESULTS

A total of 126 patients (male/female: 93/33; mean age: 54.5 years) with reliable TE results were analyzed. There was good agreement between two endoscopists in assessing the presence of EV and high-risk EV (kappa value: 0.82 and 0.96). Forty-eight (38.1%) patients had EV (small: 35; high risk: 13). There was correlation between TE result and EV size (r = 0.515, P < 0.001). TE, APRI, and PLT were similar; however, superior to AAR in the diagnostic accuracies for EV and high-risk EV. In high-risk EV prediction, the negative predictive value (NPV) was 97%, 98%, and 98%, with cut-offs of 21 kPa, 1.24, and 110 (× 10(9) /L) for TE, APRI, and PLT, respectively.

CONCLUSIONS

For compensated patients with HBV-related cirrhosis, TE, APRI, and PLT are useful in excluding high-risk EV with high NPV.

Performance of real-time strain elastography, transient elastography, and aspartate-to-platelet ratio index in the assessment of fibrosis in chronic hepatitis C

OBJECTIVE

The purpose of this article is to evaluate the diagnostic performance of transient elastography, real-time strain elastography, and aspartate-to-platelet ratio index in assessing fibrosis in patients with chronic hepatitis C by using histologic Metavir scores as reference standard.

SUBJECTS AND METHODS

Consecutive patients with chronic hepatitis C scheduled for liver biopsy were enrolled. Liver biopsy was performed on the same day as transient elastography and real-time strain elastography. Transient elastography and real-time strain elastography were performed in the same patient encounter by a single investigator using a medical device based on elastometry and an ultrasound machine, respectively. Diagnostic performance was assessed by using receiver operating characteristic curves and area under the receiver operating characteristic curve (AUC) analysis.

RESULTS

One hundred thirty patients (91 men and 39 women) were analyzed. The cutoff values for transient elastography, real-time strain elastography, and aspartate-to-platelet ratio index were 6.9 kPa, 1.82, and 0.37, respectively, for fibrosis score of 2 or higher; 7.3 kPa, 1.86, and 0.70, respectively, for fibrosis score of 3 or higher; and 9.3 kPa, 2.33, and 0.70, respectively, for fibrosis score of 4. AUC values of transient elastography, real-time strain elastography, aspartate-to-platelet ratio index were 0.88, 0.74, and 0.86, respectively, for fibrosis score of 2 or higher; 0.95, 0.80, and 0.89, respectively, for fibrosis score of 3 or higher; and 0.97, 0.80, and 0.84, respectively, for fibrosis score of 4. A combination of the three methods, when two of three were in agreement, showed AUC curves of 0.93, 0.95, and 0.95 for fibrosis scores of 2 or higher, 3 or higher, and 4, respectively.

CONCLUSION

Transient elastography, real-time strain elastography, and aspartate-to-platelet ratio index values were correlated with histologic stages of fibrosis. Transient elastography offered excellent diagnostic performance in assessing severe fibrosis and cirrhosis. Real-time elastography does not yet have the potential to substitute for transient elastography in the assessment of liver fibrosis.

How many valid measurements are necessary to assess liver fibrosis using FibroScan® in patients with chronic viral hepatitis? An analysis of subjects with at least 10 valid measurements

PURPOSE

Using FibroScan® to obtain a reliable liver stiffness measurement (LSM) may require more than 10 valid measurements (VMs), according to the manufacturer's recommendations. However, this requirement lacks scientific evidence in support thereof. We investigated the minimal number of VMs required to assess liver fibrosis without significant loss of accuracy in patients with chronic hepatitis B (CHB) and C (CHC) and predictors of discordance between LSM and liver biopsy (LB).

MATERIALS AND METHODS

Between January 2005 and December 2009, we prospectively enrolled 182 patients with CHB and 68 patients with CHC who were to undergo LB and LSM before starting antiviral treatment. Only LSMs with at least 10 VMs were considered reliable. The Batts and Ludwig scoring system was used for histologic assessment.

RESULTS

The mean age and body mass index were 46.0 years and 23.4 kg/m² in patients with CHB and 49.7 years and 23.1 kg/m² in those with CHC, respectively. The median elasticity scores from the first 3, first 5, and all VMs taken significantly predicted fibrosis stages ≥F2 and F4 (all p<0.05) without significant differences (all p>0.05 by DeLong's method). Alanine aminotransferase (ALT) was the only predictor of discordance in fibrosis stage as estimated by the median elasticity score from the first 3 VMs and by LB in patients with CHB, whereas no significant predictor was identified in those with CHC.

CONCLUSION

After comparison of patients who had more than 10 valid measurements for LSM, three VMs may be enough to assess liver fibrosis using LSM without significant loss of accuracy in patients with CHC and patients with CHB. However, ALT should be considered when interpreting LSM for patients with CHB.

Transient elastography in patients with celiac disease: a noninvasive method to detect liver involvement associated with celiac disease

BACKGROUND

Liver involvement in celiac disease (CD) is clinically relevant and could require specific treatment in addition to gluten-free diet (GFD). Transient elastography (TE), a noninvasive tool for assessing liver stiffness (LS), has widely been reported as an accurate surrogate marker of liver fibrosis.

AIMS

To prospectively identify celiac patients with liver involvement by TE and to assess the effect of GFD.

MATERIAL AND METHODS

Ninety-five histologically confirmed CD patients (24 newly diagnosed) were consecutively evaluated by TE and compared with 146 patients with chronic hepatitis C (HCV) and 54 healthy subjects.

RESULTS

LS ranged between 2.8 and 6.7 kPa (median 4.9) in healthy subjects, defining 6.9 kPa as the upper reference limit (2 SD above the mean levels). TE was above 6.9 kPa in 10 (10.5%) CD patients. Median TE values resulted significantly higher in CD patients with hypertransaminasemia than those without [6.1 vs. 4.2 kPa (p < 0.01)]. Among the 24 newly diagnosed patients with CD, median TE values declined from 4.4 to 4 kPa, after 6 months of GFD, resulting below 6.9 kPa in 100% of the patients.

CONCLUSIONS

A subset of CD patients with hypertransaminasemia showed liver involvement by TE. Accordingly, based on its accuracy in predicting liver fibrosis, TE could be used to identify those CD patients suitable for liver biopsy.

Clinical applications of transient elastography

Chronic liver disease represents a major public health problem, accounting for significant morbidity and mortality worldwide. As prognosis and management depend mainly on the amount and progression of liver fibrosis, accurate quantification of liver fibrosis is essential for therapeutic decision-making and follow-up of chronic liver diseases. Even though liver biopsy is the gold standard for evaluation of liver fibrosis, non-invasive methods that could substitute for invasive procedures have been investigated during past decades. Transient elastography (TE, FibroScan®) is a novel non-invasive method for assessment of liver fibrosis with chronic liver disease. TE can be performed in the outpatient clinic with immediate results and excellent reproducibility. Its diagnostic accuracy for assessment of liver fibrosis has been demonstrated in patients with chronic viral hepatitis; as a result, unnecessary liver biopsy could be avoided in some patients. Moreover, due to its excellent patient acceptance, TE could be used for monitoring disease progression or predicting development of liver-related complications. This review aims at discussing the usefulness of TE in clinical practice.

Stability of liver fibrosis among HCV-infected injection drug users

BACKGROUND

There are few published data characterizing patterns of liver stiffness measurements (LSMs) among HCV-infected persons and their potential impact on clinical decisions (for example, deferring treatment and hepatocellular carcinoma surveillance).

METHODS

A total of 591 HCV-infected injection drug users in a community-based cohort had four LSMs. We used semi-parametric latent class growth modelling to identify patterns, which then became a gold standard against which we characterized validity of information from the initial measurements.

RESULTS

Median age was 49, 68% were male, 92% African-American and 33% HIV-coinfected. The median LSM at visit 1 was 6.7 kPa (IQR 5.3-8.8). Over a median 1.75 years, LSM measures were stable; median change between visits was 0 kPa (IQR -1.4-1.7). Only 3% had evidence of fibrosis progression. Other groups included stable patterns of no fibrosis (59%), moderate fibrosis (21%), severe fibrosis (7%) and cirrhosis (9%). Individuals with fibrosis progression were more likely to be HIV-infected than those with stable low fibrosis (P<0.001). The diagnostic accuracy of the first LSM for identification of need for cancer surveillance (cirrhosis ≥12.3 kPa) was high (positive predictive value =97%). Although no single low LSM had high negative predictive value for significant fibrosis (metavir <2), individuals with two or more low results rarely had progression.

CONCLUSIONS

These data underscore the stability of liver fibrosis in a cohort of predominantly African-American HCV-infected persons over 1.75 years, support using LSMs to monitor untreated persons at risk for progression and assess need for hepatocellular carcinoma surveillance.

How many valid measurements are necessary to assess liver fibrosis using FibroScan® in patients with chronic viral hepatitis? An analysis of subjects with at least 10 valid measurements

PURPOSE

Using FibroScan® to obtain a reliable liver stiffness measurement (LSM) may require more than 10 valid measurements (VMs), according to the manufacturer's recommendations. However, this requirement lacks scientific evidence in support thereof. We investigated the minimal number of VMs required to assess liver fibrosis without significant loss of accuracy in patients with chronic hepatitis B (CHB) and C (CHC) and predictors of discordance between LSM and liver biopsy (LB).

MATERIALS AND METHODS

Between January 2005 and December 2009, we prospectively enrolled 182 patients with CHB and 68 patients with CHC who were to undergo LB and LSM before starting antiviral treatment. Only LSMs with at least 10 VMs were considered reliable. The Batts and Ludwig scoring system was used for histologic assessment.

RESULTS

The mean age and body mass index were 46.0 years and 23.4 kg/m² in patients with CHB and 49.7 years and 23.1 kg/m² in those with CHC, respectively. The median elasticity scores from the first 3, first 5, and all VMs taken significantly predicted fibrosis stages ≥F2 and F4 (all p<0.05) without significant differences (all p>0.05 by DeLong's method). Alanine aminotransferase (ALT) was the only predictor of discordance in fibrosis stage as estimated by the median elasticity score from the first 3 VMs and by LB in patients with CHB, whereas no significant predictor was identified in those with CHC.

CONCLUSION

After comparison of patients who had more than 10 valid measurements for LSM, three VMs may be enough to assess liver fibrosis using LSM without significant loss of accuracy in patients with CHC and patients with CHB. However, ALT should be considered when interpreting LSM for patients with CHB.

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

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

Acoustic radiation force impulse imaging (ARFI) for non-invasive detection of liver fibrosis: examination standards and evaluation of interlobe differences in healthy subjects and chronic liver disease

OBJECTIVE

Acoustic radiation force impulse imaging (ARFI) is a non-invasive method for the quantification of liver stiffness. We aimed to develop standards for the measuring procedure and studied the impact of different measuring sites.

MATERIALS AND METHODS

ARFI was tested in a tissue phantom and in 50 healthy volunteers. In addition, 116 patients with chronic liver disease underwent ARFI. The results were compared with histological staging (non-viral liver disease) and transient elastography (hepatitis C). ARFI diagnostic performance was evaluated with receiver operating characteristic curves.

RESULTS

ARFI results were not normally distributed in >20% of cases. Deep inspiration significantly increased ARFI values by 13% (p < 0.05). The mean shear-wave velocity in healthy individuals was 1.28 ± 0.19 m/s in the left liver lobe and 1.15 ± 0.17 m/s in the right liver lobe (p < 0.001). Similarly, in 79/116 patients with chronic liver disease a significant difference of shear-wave velocity between both liver lobes was detected. The histological staging correlated with ARFI results of the biopsy site (r = 0.661, p < 0.001) in non-viral liver disease (n = 47). The mean shear-wave velocity in cases with F1 and F2 fibrosis was increased in the left compared with the right liver lobe (2.1 ± 0.73 m/s vs. 1.75 ± 0.89 m/s, p = 0.041). Similar results were obtained in patients with hepatitis C (n = 69).

CONCLUSION

Our study strengthens the necessity for definition of examination standards and demonstrates the usefulness of ARFI in non-viral liver disease. Interlobe variations of liver stiffness demand further investigation.

Comparison of accuracy of fibrosis degree classifications by liver biopsy and non-invasive tests in chronic hepatitis C

BACKGROUND

Non-invasive tests have been constructed and evaluated mainly for binary diagnoses such as significant fibrosis. Recently, detailed fibrosis classifications for several non-invasive tests have been developed, but their accuracy has not been thoroughly evaluated in comparison to liver biopsy, especially in clinical practice and for Fibroscan. Therefore, the main aim of the present study was to evaluate the accuracy of detailed fibrosis classifications available for non-invasive tests and liver biopsy. The secondary aim was to validate these accuracies in independent populations.

METHODS

Four HCV populations provided 2,068 patients with liver biopsy, four different pathologist skill-levels and non-invasive tests. Results were expressed as percentages of correctly classified patients.

RESULTS

In population #1 including 205 patients and comparing liver biopsy (reference: consensus reading by two experts) and blood tests, Metavir fibrosis (FM) stage accuracy was 64.4% in local pathologists vs. 82.2% (p < 10-3) in single expert pathologist. Significant discrepancy (≥ 2FM vs reference histological result) rates were: Fibrotest: 17.2%, FibroMeter2G: 5.6%, local pathologists: 4.9%, FibroMeter3G: 0.5%, expert pathologist: 0% (p < 10-3). In population #2 including 1,056 patients and comparing blood tests, the discrepancy scores, taking into account the error magnitude, of detailed fibrosis classification were significantly different between FibroMeter2G (0.30 ± 0.55) and FibroMeter3G (0.14 ± 0.37, p < 10-3) or Fibrotest (0.84 ± 0.80, p < 10-3). In population #3 (and #4) including 458 (359) patients and comparing blood tests and Fibroscan, accuracies of detailed fibrosis classification were, respectively: Fibrotest: 42.5% (33.5%), Fibroscan: 64.9% (50.7%), FibroMeter2G: 68.7% (68.2%), FibroMeter3G: 77.1% (83.4%), p < 10-3 (p < 10-3). Significant discrepancy (≥ 2 FM) rates were, respectively: Fibrotest: 21.3% (22.2%), Fibroscan: 12.9% (12.3%), FibroMeter2G: 5.7% (6.0%), FibroMeter3G: 0.9% (0.9%), p < 10-3 (p < 10-3).

CONCLUSIONS

The accuracy in detailed fibrosis classification of the best-performing blood test outperforms liver biopsy read by a local pathologist, i.e., in clinical practice; however, the classification precision is apparently lesser. This detailed classification accuracy is much lower than that of significant fibrosis with Fibroscan and even Fibrotest but higher with FibroMeter3G. FibroMeter classification accuracy was significantly higher than those of other non-invasive tests. Finally, for hepatitis C evaluation in clinical practice, fibrosis degree can be evaluated using an accurate blood test.