Is ARFI elastography reliable for predicting fibrosis severity in chronic HCV hepatitis?

Investigating the role of ultrasound-based shear wave elastography in kidney transplanted patients: correlation between non-invasive fibrosis detection, kidney dysfunction and biopsy results-a systematic review and meta-analysis

INTRODUCTION

Interstitial fibrosis and tubular atrophy are leading causes of renal allograft failure. Shear wave elastography could be a promising noninvasive method for providing information on the state of the kidney, with specific regard to fibrosis but currently available data in the literature are controversial. Our study aimed to analyze the correlation between shear wave elastography and various kidney dysfunction measures.

METHODS

This review was registered on PROSPERO (CRD42021283152). We systematically searched three major databases (MEDLINE, Embase, and CENTRAL) for articles concerning renal transplant recipients, shear wave elastography, fibrosis, and kidney dysfunction. Meta-analytical calculations for pooled Pearson and Spearman correlation coefficients (r) were interpreted with 95% confidence intervals (CIs). Heterogeneity was tested with Cochran's Q test. I2 statistic and 95% CI were reported as a measurement of between-study heterogeneity. Study quality was assessed with the QUADAS2 tool.

RESULTS

In total, 16 studies were included in our meta-analysis. Results showed a moderate correlation between kidney stiffness and interstitial fibrosis and tubular atrophy, graded according to BANFF classification, on biopsy findings for pooled Pearson (r = 0.48; CI: 0.20, 0.69; I2 = 84%) and Spearman correlations (r = 0.57; CI: 0.35, 0.72; I2 = 74%). When compared to kidney dysfunction parameters, we found a moderate correlation between shear wave elastography and resistive index (r = 0.34 CI: 0.13, 0.51; I2 = 67%) and between shear wave elastography and estimated Glomerular Filtration Rate (eGFR) (r = -0.65; CI: - 0.81, - 0.40; I2 = 73%). All our outcomes had marked heterogeneity.

CONCLUSION

Our results showed a moderate correlation between kidney stiffness measured by shear wave elastography and biopsy results. While noninvasive assessment of kidney fibrosis after transplantation is an important clinical goal, there is insufficient evidence to support the use of elastography over the performance of a kidney biopsy.

Imaging-based noninvasive liver disease assessment for staging liver fibrosis in chronic liver disease: A systematic review supporting the AASLD Practice Guideline

BACKGROUND AND AIMS

Transient elastography (TE), shear wave elastography, and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F).

APPROACH AND RESULTS

A comprehensive search for studies assessing LSM by TE, shear wave elastography, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), using histopathology as the standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV coinfection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults.

CONCLUSIONS

LSM from TE, shear wave elastography, and MRE shows acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

The Influence of Metabolic Factors in Patients with Chronic Viral Hepatitis C Who Received Oral Antiviral Treatment

Hepatic diseases pose a significant public health concern. Regardless of the severity of hepatic fibrosis, treatment is recommended for all chronic hepatitis C virus (HCV) subjects. However, fibrosis and steatosis assessment remains crucial for evaluating the prognosis, progression, and hepatic disease monitoring, particularly following the treatment with direct-acting antivirals (DAAs). The aim of our study was to evaluate the impact of metabolic factors and the extent of hepatic fibrosis and fat accumulation in chronic HCV infection subjects. Additionally, another objective was to investigate modifications regarding fibrosis and steatosis three months after a successful sustained viral response (SVR). A total of 100 patients with compensated cirrhosis and chronic hepatitis C (CHC) were included in our study. These patients received treatment with DAA and underwent Fibromax assessment before and three months post SVR. After DAA treatment, a significant decrease was observed in the degree of hepatic fibrosis and hepatic steatosis. This regression was evident three months following the achievement of SVR. Chronic viral hepatitis C may trigger risk factors for metabolic syndromes, such as obesity and type 2 diabetes mellitus. Conclusions: It is crucial to monitor metabolic factors and take timely measures to prevent or treat metabolic syndrome in patients with chronic viral hepatitis C.

Vitamin D Status and Steatohepatitis in Obese Diabetic and Non-Diabetic Patients

BACKGROUND AND AIMS

The presence of steatohepatitis in obese patients can be multifactorial. The current study tries to determine the differences between diabetic and non-diabetic patients regarding the presence of steatohepatitis. We evaluated sequential liver samples and collected the times of bariatric surgery to assess the presence of NASH in patients with obesity, in the circuit of bariatric surgery.

METHODS

We performed a retrospective study of 49 patients presenting high-grade obesity in the circuit of bariatric surgery, with liver biopsy. The patients underwent bariatric surgery at a single center in France and were followed for 2 years. The liver biopsies were performed intraoperatively on all 49 patients before the bariatric surgery. The primary endpoint of the study was to evaluate the relationships between steatohepatitis/liver fibrosis and the presence of diabetes and to evaluate the current relationships between the biochemical work-ups. Special importance was accorded to the correlations between vitamin D levels and the presence of hepatic steatosis, due to the antifibrogenic pattern in the liver, as shown in many important papers in the field.

RESULTS

Significant correlations were found between the presence of liver fibrosis and the presence of diabetes (p = 0.022), but not regarding the antidiabetic treatment. An important correlation was found between the vitamin D levels and the presence of liver fibrosis, as well as with the levels of A1C hemoglobin and LDL cholesterol levels.

CONCLUSIONS

Vitamin D deficiency presents a strong correlation with hepatic steatosis in individuals with morbid obesity. Correcting vitamin D deficiency may present a beneficial role in treating hepatic steatosis, diabetes, and cardiovascular risk in patients with morbid obesity.

Diagnostic Performance of Acoustic Radiation Force Impulse Imaging in Evaluating Liver Fibrosis in Patients with Chronic Hepatitis B Infection: A Cross-Sectional Study

Background  Acoustic radiation force impulse point shear wave elastography (ARFI-pSWE), measuring shear-wave velocity (SWV), has been utilized to examine the liver stiffness caused by different etiologies. However, information on its reliability in staging liver fibrosis in chronic hepatitis B (CHB) patients is scarce.

Purpose  The aim of the study is to examine the diagnostic performance of ARFI-pSWE and determine the optimal SWV cut-off values to predict significant fibrosis ( F ≥2) and cirrhosis (F4) in CHB patients.

Material and Methods  All 114 adult CHB patients visiting the University Medical Center, Ho Chi Minh City, Vietnam between February 2019 and March 2021 underwent liver stiffness measurement using ARFI-pSWE and FibroScan. SWV results were tested against FibroScan for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The area under the receiver operating characteristic (AUROC) curve was used to identify the optimal SWV cut-off values.

Results  There was a strong agreement between ARFI-pSWE and FibroScan ( r  = 0.92, p <0.001). The optimal SWV cut-off value for detecting significant fibrosis was 1.37 m/s with an AUROC of 0.975, sensitivity of 83.3%, specificity of 100%, PPV of 100%, and NPV of 81%. The optimal cut-off value for predicting cirrhosis was 1.70 m/s with an AUROC of 0.986, sensitivity of 97%, specificity of 93%, PPV of 95%, and NPV of 96%.

Conclusion  ARFI-pSWE could be an effective technique for evaluating liver fibrosis in CHB patients. SWV cut-off values of 1.37 and 1.70 m/s could be used to diagnose significant fibrosis and cirrhosis, respectively.

Shear Wave Elastography in Diagnosing Secondary Hyperparathyroidism

This study evaluates the diagnostic value of two-dimensional shear wave elastography (2 D-SWE) technique in the evaluation of hyperplastic parathyroid glands in cases with secondary and tertiary hyperparathyroidism. A total of 59 patients (end-stage renal disease, under supplemental dialysis program) with visible parathyroid hyperplastic glands on ultrasound, confirmed by biochemical assay and scintigraphy, were enrolled; they were examined on grayscale ultrasound and 2 D shear wave elastography. We determined the elasticity index (EI) in the parathyroid gland, thyroid parenchyma and surrounding muscles, and the elasticity ratio of hyperplastic parathyroid glands compared to muscle, specifically sternocleidomastoid muscle. Patients presented fibrocystic bone disease with secondary hyperparathyroidism induced by end-stage chronic kidney disease; being on prolonged chronic dialysis therapy, they had positive sestamibi scintigraphy and high values of serum parathormone (1141.04 pg/mL). Nodules placed posterior to the thyroid capsule that were cystic, had a hypoechoic aspect, and were homogenous with an independent afferent artery were found. Mean EI in the parathyroid gland was 7.83 kPa, the median value in thyroid parenchyma was 13.76 kPa, and mean muscle EI value was 15.78 kPa. The observed mean parathyroid/muscle SWE ratio was 0.5356 and the value for parathyroid/normal thyroid parenchyma was 0.5995. Using receiver operating characteristic (ROC) analysis, we found that EI below 9.74 kPa correctly identifies parathyroid tissue, with a sensitivity of 94.8%, specificity of 90.7%, and accuracy of 92.26% when compared to normal thyroid tissue. Compared with the muscle tissue, we identified that EI below 9.98 kPa has a sensitivity, specificity, and accuracy of 93.8%, 90.7%, and 91.75%, respectively. Ultrasound elastography is a helpful tool in identifying parathyroid hyperplasia in patients with chronic kidney disease. A cutoff value of 9.98 kPa can be used in 2 D-SWE for accurate diagnosis of parathyroid disease.

The clinical usefulness of elastography in the evaluation of nonalcoholic fatty liver disease patients: A biopsy-controlled study

BACKGROUND

We aimed at determination of the usefulness of elastography [acoustic radiation force impulse (ARFI) and FibroScan] for evaluation of nonalcoholic fatty liver disease (NAFLD) patients.

PATIENTS AND METHODS

A prospective cross-sectional study included 60 biopsy-proven NAFLD patients (mean age: 45 years) was carried out. All patients were subjected to lab works, liver biopsy, and measurement of liver stiffness by ARFI and FibroScan and steatosis by controlled attenuation parameter (CAP). CAP measurements were adjusted for the presence of NAFLD and presence or absence of diabetes and according to BMI.

RESULTS

Linear regression analysis showed that CAP is an independent predictor for significant hepatic steatosis (P<0.001). No significant difference was found in diagnostic accuracy between adjusted and nonadjusted CAP values for diagnosis of mild (>S1) or significant (>S2) hepatic steatosis (P=0.17 and 0.29 respectively). The median ARFI velocities for F1, F2, F3, and F4 were 0.92, 1.08, 1.07, and 2.58 m/s, respectively. Although there was an overall significant increase in ARFI values across the fibrosis grades (P<0.04), the difference in ARFI values was only significant between fibrosis grades F1 and F4 (P=0.02).

CONCLUSION

Elastography is a promising noninvasive tool for diagnosis and grading of hepatic steatosis and fibrosis in patients with NAFLD/nonalcoholic steatohepatitis with good sensitivity and specificity, especially in moderate to marked grades.

Chronic hepatitis C infection - Noninvasive assessment of liver fibrosis in the era of direct acting antivirals

Significant advancements in the diagnosis and treatment of chronic hepatitis C infection and its associated fibrosis have revolutionized treatment of these patients over the last several years. Liver biopsy, the gold standard diagnostic method for evaluating liver fibrosis level, was routinely used prior to initiation of hepatitis C therapy, placing patients at an inherent risk of adverse events. The recent advent of noninvasive serologic and nonserologic measures of hepatic fibrosis level has reduced the need for liver biopsy significantly, thereby minimizing its associated risks. These noninvasive methods have been extensively studied in the era of interferon therapies and are increasingly recognized in the realm of direct acting antiviral agents as well. Their validation of use after having achieved a sustained virologic response is yet to occur, but the future remains promising. This review focuses on the various non-invasive diagnostic modalities of liver fibrosis and discusses how they can be applied to the care of patients undergoing direct acting antiviral therapy for hepatitis C. In the constantly evolving landscape of hepatitis C therapy, the review underscores the important prognostic value of fibrosis staging prior to HCV treatment and suggests potential uses for non-invasive fibrosis assessment following successful HCV eradication.

Liver ultrasound elastography for the evaluation of periportal fibrosis in schistosomiasis mansoni: A cross-sectional study

BACKGROUND

ARFI elastrography has been used as a noninvasive method to assess the severity of liver fibrosis in viral hepatitis, although with few studies in schistosomiasis mansoni. We aimed to evaluate the performance of point shear wave elastography (pSWE) for predicting significant periportal fibrosis (PPF) in schistosomotic patients and to determine its best cutoff point.

METHODOLOGY/PRINCIPAL FINDINGS

This cross-sectional study included 358 adult schistosomotic patients subjected to US and pSWE on the right lobe. Two hundred two patients (62.0%) were women, with a median age of 54 (ranging 18-92) years. The pSWE measurements were compared to the US patterns of PPF, as gold standard, according to the Niamey classification. The performance of pSWE was calculated as the area under the ROC curve (AUC). Patients were further classified into two groups: 86 patients with mild PPF and 272 patients with significant PPF. The median pSWE of the significant fibrosis group was higher (1.40 m/s) than that of mild fibrosis group (1.14 m/s, p<0.001). AUC was 0.719 with ≤1.11 m/s as the best cutoff value for excluding significant PPF. Sensitivity and negative predictive values were 80.5% and 40.5%, respectively. Whereas, for confirming significant PPF, the best cutoff value was >1.39 m/s, with specificity of 86.1% and positive predictive value of 92.0%.

CONCLUSIONS/SIGNIFICANCE

pSWE was able to differentiate significant from mild PPF, with better performance to predict significant PPF.

Longitudinal assessment of hepatic fibrosis in responders to direct-acting antivirals for recurrent hepatitis C after liver transplantation using noninvasive methods

Successful eradication of recurrent hepatitis C virus (HCV) infection following liver transplantation (HCV) improves graft survival. This study aimed at evaluation of hepatic fibrosis changes among long-term responders to DAA therapy for recurrent HCV after liver transplantation using noninvasive methods. Patients with significant hepatic fibrosis (≥F2) who achieved SVR12 after treatment with DAAs for recurrent HCV were included (n = 52). Hepatic fibrosis status was assessed, noninvasively, by calculation of fibrosis-4 score (FIB-4) and Aspartate Aminotransferase Platelet Ratio Index (APRI) and by measurement of graft stiffness using FibroScan at baseline and 12 and 18 months post-treatment. Acoustic radiation force imaging (ARFI) was done for all patients 12 and 18 months post-treatment. Patients were classified into two groups based on baseline liver stiffness measurement (LSM) by FibroScan; significant fibrosis (F2; n = 28) and advanced fibrosis groups (≥F3). Over 18-month follow-up period, there was serial improvement of FIB-4, APRI, and LSM by FibroScan in both groups. Higher baseline LSM and delayed initiation of antiviral therapy were significant predictors of lack of fibrosis regression (P-value 0.01 and 0.04, respectively). Fibroindices and LSM improved over time in liver transplant recipients who responded to DAAs. Baseline LSM can predict post-treatment fibrosis regression.

Acoustic Radiation Force Impulse Elastography in Post-transplant Recurrent Hepatitis C in Living Donor Liver Transplantation

OBJECTIVE

The aim of the study was to evaluate the efficacy of liver fibrosis (LF) with acoustic radiation force impulse (ARFI) elastography for post-transplant (post-LT) HCV recurrence.

PATIENTS AND METHODS

We enrolled 89 adult recipients of living donor liver transplantation (LDLT) who had HCV, with or without post-LT HCV recurrence and treated or not treated. The post-LT HCV recurrence was diagnosed on the basis of RNA viral load present. ARFI examination was performed every 3 months for all patients, with shear wave velocity (SWV) obtained quantitatively in m/s and correlated with histopathologic fibrosis scoring of liver biopsy (LB).

RESULTS

There were 50 (50 of 89) patients without HCV recurrence and 39 (39 of 89) with post-LT recurrence in the 89 patients studied. The recurrent group had significantly higher median SWVs (1.87 ± 0.52 vs 1.37 ± 0.52 m/s, P < .0001), in which 18 (18 of 39) patients had antiviral drug treatment and obtained significant improvement with SWVs from 1.83 ± 0.49 to 1.68 ± 0.56 m/s, P = .043. The correlations of LF staging between ARFI elastography and Ishak histopathologic LF scores showed great significance, P = .045. The HCV RNA titer after antiviral treatment decreased from 3,831,750 to 0, P < .0001, but the RNA titer of nontreated patients remained high and the median SWV increased. The Ishak LF staging in the nontreated group progressed from stage 1 to 2, P = .012 and SWV increased from 1.69 ± 0.54 to 1.91 ± 0.66 m/s, P = .085 at 1-year follow-up.

CONCLUSION

ARFI elastography has efficient quantitative LF monitoring correlated with histopathologic staging for post-LT HCV recurrence. It could be an alternative, noninvasive method for frequent LB in the disease follow-up.

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

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

Acoustic radiation force impulse (ARFI) elastography in a cohort of alpha-1 antitrypsin-deficient individuals and healthy volunteers

Background

Acoustic radiation force impulse (ARFI) elastography has been used to assess liver stiffness non-invasively. However, its usefulness in alpha-1 antitripsin-deficient (AATD) individuals is unknown.

Purpose

To assess if liver fibrosis is present in a cohort of AATD individuals using ARFI elastography.

Material and Methods

Eighty-three participants aged 38–39 years, except for two who were aged 40 years, underwent ultrasound elastography of the liver with ARFI technique. Twenty-nine were homozygote ZZ genotype, PiZZ (14 men, 15 women); 12 were SZ genotype, Pi SZ (8 men, 4 women), and 42 were healthy volunteers, PiMM (16 men, 26 women). Three specific liver anatomical regions were examined: segments 2/3 (left lobe) in the subcostal plane, and 5/6 and 7/8 (right lobe) in the intercostal space. In each region, three measurements were registered.

Results

There was no statistically significant difference between ARFI-median in the AATD group and the control group (P value = 0.877) and neither between AATD groups (PiZZ and PiSZ) with a P value = 0.259. The ARFI-median was lower in the right liver lobe than in the left lobe in all groups and the difference between both lobes was statistically significant (P = 0.001). No statistically significant difference was found in ARFI-median of the right liver lobe between the AATD group and the control group (P = 0.759), nor between the AATD group (P = 0.384). No gender difference was found in ARFI-median.

Conclusions

ARFI values in AATD individuals aged 38–39 years showed no difference compare to healthy participants.

Hepatitis C virus-induced CCL5 secretion from macrophages activates hepatic stellate cells

Hepatitis C virus (HCV)-mediated chronic liver disease is a serious health problem around the world and often causes fibrosis/cirrhosis and hepatocellular carcinoma. The mechanism of liver disease progression during HCV infection is still unclear, although inflammation is believed to be an important player in disease pathogenesis. We previously reported that macrophages including Kupffer cells exposed to HCV induce proinflammatory cytokines. These secreted cytokines may activate hepatic stellate cells (HSCs) toward fibrosis. In this study, we examined crosstalk between macrophages and HSCs following HCV infection. Primary human HSCs and immortalized HSCs (LX2 cells) were incubated with conditioned medium derived from HCV-exposed human macrophages. Expression of inflammasome and fibrosis-related genes in these cells was examined, with increased expression of inflammatory (NLR family pyrin domain containing 3, interleukins 1β and 6, and cysteine-cysteine chemokine ligand 5 [CCL5]) and profibrogenic (transforming growth factor β1, collagen type 4 alpha 1, matrix metalloproteinase 2, and alpha-smooth muscle actin) markers. Further investigation suggested that CCL5, secreted from HCV-exposed macrophages, activates inflammasome and fibrosis markers in HSCs and that neutralizing antibody to CCL5 inhibited activation.

CONCLUSION

Together, our results demonstrate that human macrophages exposed to HCV induce CCL5 secretion, which plays a significant role in hepatic inflammation and fibrosis. (Hepatology 2017;66:746-757).

The value of ElastPQ for the evaluation of liver stiffness in patients with B and C chronic hepatopathies

The aim of this study was to evaluate the diagnostic performance of a point shear wave elastography using ARFI technique - ElastPQ, in patients with B and C chronic hepatopathies, using Transient Elastography (TE) as the reference method, since it is a validated method for liver fibrosis assessment.

SUBJECTS AND METHODS

the study included 228 consecutive subjects with chronic hepatopathies (26% HBV, 74% HCV) from whom 51% had liver cirrhosis. Liver stiffness (LS) was evaluated in the same session by means of 2 elastographic methods: TE (FibroScan, EchoSens) and ElastPQ (Affinity, Philips) techniques. For TE 10 valid LS measurements were performed for each patient and the median value was calculated. Reliable LS measurements by TE (M or XL probe) were considered the median value of 10LS measurements with a success rate ≥60% and an interquartile range <30%. For ElastPQ we calculated the median value of 10LS measurements in the liver parenchyma, at least 1cm below the capsule, avoiding large vessels. For differentiating between stages of liver fibrosis we used the TE cut-off values published in the Tsochatzis meta-analysis: significant fibrosis (F≥2)- 7.0kPa, severe fibrosis (F≥3)- 9.5kPa and for liver cirrhosis (F=4)-12kPa (Tsochatzis et al., 2011). The areas under the receiver operating characteristic curve (AUROCs) were used to assess the diagnostic performance of ElastPQ, correlations between ElastPQ and TE were evaluated.

RESULTS

Valid LS measurements were obtained in 90.7% (207/228) cases by means of TE and in 98.7% (225/228) cases with ElastPQ. In the final analysis 205 patients were included. The ElastPQ values ranged from 2.32 to 44.07kPa (median=10.42kPa). Based on TE cut-off values (Tsochatzis et al., 2011) we divided our cohort into 4 groups: F0-F1:61/205 (29.8%); F2: 14/205 (6.8%); F3: 15/205 (7.3%); F=4: 115/205 (56.1%). The best cut-off values for discriminating, significant, severe fibrosis and cirrhosis were 7.2, 8.5 and 8.9kPa, respectively. The AUROCs were calculated considering TE as the reference method: 0.94 for significant fibrosis (F≥2), 0.97 for severe fibrosis (F≥3) and 0.97 for cirrhosis (F=4). In our cohort there was a strong correlation between measurements obtained by Transient Elastography and ElastPQ (r=0.85, p<0.001).

CONCLUSIONS

ElastPQ seems to have a good diagnostic accuracy for staging liver fibrosis.

Concordance of non-invasive mechanical and serum tests for liver fibrosis evaluation in chronic hepatitis C

AIM

To determine the sensitivity and specificity of liver stiffness measurement (LSM) and serum markers (SM) for liver fibrosis evaluation in chronic hepatitis C.

METHODS

Between 2012 and 2014, 81 consecutive hepatitis C virus (HCV) patients had METAVIR score from liver biopsy compared with concurrent results from LSM [transient elastography (TE) [FibroScan^®/ARFI technology (Virtual Touch^®)] and SM [FIB-4/aspartate aminotransferase-to-platelet ratio index (APRI)]. The diagnostic performance of these tests was assessed using receiver operating characteristic curves. The optimal cut-off levels of each test were chosen to define fibrosis stages F ≥ 2, F ≥ 3 and F = 4. The Kappa index set the concordance analysis.

RESULTS

Fifty point six percent were female and the median age was 51 years (30-78). Fifty-six patients (70%) were treatment-naïve. The optimal cut-off values for predicting F ≥ 2 stage fibrosis assessed by TE were 6.6 kPa, for acoustic radiation force impulse (ARFI) 1.22 m/s, for APRI 0.75 and for FIB-4 1.47. For F ≥ 3 TE was 8.9 kPa, ARFI was 1.48 m/s, APRI was 0.75, and FIB-4 was 2. For F = 4, TE was 12.2 kPa, ARFI was 1.77 m/s, APRI was 1.46, and FIB-4 was 3.91. The APRI could not distinguish between F2 and F3, P = 0.92. The negative predictive value for F = 4 for TE and ARFI was 100%. Kappa index values for F ≥ 3 METAVIR score for TE, ARFI and FIB-4 were 0.687, 0.606 and 0.654, respectively. This demonstrates strong concordance between all three screening methods, and moderate to strong concordance between them and APRI (Kappa index = 0.507).

CONCLUSION

Given the costs and accessibility of LSM methods, and the similarity with the outcomes of SM, we suggest that FIB-4 as well as TE and ARFI may be useful indicators of the degree of liver fibrosis. This is of particular importance to developing countries.

Prediction of development of hepatocellular carcinoma using a new scoring system involving virtual touch quantification in patients with chronic liver diseases

BACKGROUND

This study aimed to establish a new scoring system that combined several risk factors, including virtual touch quantification (VTQ) values and fasting plasma glucose (FPG) levels, for predicting the development of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

METHODS

A total of 1808 chronic liver disease patients who underwent VTQ measurement were analyzed. Risk factors for developing HCC were selected by multivariate Cox proportional hazards models.

RESULTS

VTQ (>1.33 m/s), FPG (≥110 mg/dl), sex (male), age (≥55 years), and α-fetoprotein (AFP) level (≥5 ng/ml) were independently selected as risk factors for HCC development by multivariate analysis. Using these parameters, we established a new scoring system (0 to 5 points), based on VTQ, FPG, sex, age, and AFP level, named VFMAP. As compared with the low VFMAP score group (0 or 1 point), the hazard ratio for the incidence of HCC was 17.37 [95 % confidence interval (CI), 2.35-128.40] in the intermediate-score group (2 or 3 points) and 66.82 (95 % CI, 9.01-495.80) in the high-score group (4 or 5 points). The area under the receiver operating characteristic curve of the VFMAP score for predicting HCC development within 5 years was 0.82 (95 % CI, 0.76-0.87), indicating a moderate diagnostic value. A VFMAP cutoff value of 3 excluded HCC within 5 years with a high negative predictive value (98.2 %).

CONCLUSION

The VFMAP score accurately predicted HCC in patients with chronic liver disease.

Diagnostic Accuracy of Acoustic Radiation Force Impulse (ARFI) in Diagnosis of Liver Fibrosis among Egyptian Patients with Chronic HCV Infection

BACKGROUND:

Acoustic radiation force impulse (ARFI) evaluates liver stiffness non-invasively and was invented recently. This technique can easily and accurately assess the degree of liver fibrosis in clinical practice.

AIM:

The aim of this study was to detect the diagnostic performance of ARFI elastography in the staging of fibrosis in some Egyptian patients with chronic HCV infection.

PATIENTS AND METHODS:

One hundred ninety patients with chronic HCV infection; 142 men and 48 women were enrolled in the study. They underwent liver biopsy examination for liver fibrosis detection. All demographic; clinical and biochemical data were recoded. ARFI examination was done for all subjects to detect liver stiffness measurement in relation to liver fibrosis detected by pathological examination of liver biopsies.

RESULTS:

Medians of liver stiffness measurement by shear wave velocity showed a significant increase as a grade of liver fibrosis increases (p ≤ 0.0001, highly significant). Liver stiffness was directly correlated to age, AST; ALT; INR and liver steatosis (p values were: 0.009; 0.0001; 0.013; 0.006 and 0.04 respectively, significant). On the other hand, liver stiffness was inversely correlated to albumin; prothrombin concentration and platelets (p values were: 0.0001; 0.001, and 0.0001, respectively, significant). We found that shear wave velocity can predict F1; F2; F3 and F4 at cut-off values: 1.22; 1.32; 1.44 and 1.8 respectively.

CONCLUSION:

ARFI is a diagnostic noninvasive promising technique for liver fibrosis diagnosis among Egyptian patients with chronic HCV infection.

[Comparison of FibroTouch and acoustic radiation force impulse in diagnosis of liver fibrosis in patients with chronic hepatitis B]

Objective: To compare transient elastorgaphy (FibroTouch) and acoustic radiation force impulse (ARFI) in diagnosis of liver fibrosis in patients with chronic hepatitis B. Methods: One hundred and forty five patients with chronic hepatitis B underwent FibroTouch and ARFI examinations in Xixi Hospital of Hangzhou from January to November 2015. The liver stiffness (LSM) was detected by FibroTouch and the liver shear wave velocity (VTQ) was detected by ARFI; liver biopsy was performed in all patients. With biopsy results as gold standards, the diagnostic values of FibroTouch and ARFI for liver fibrosis were analyzed with Spearman correlation analysis and receiver operating characteristic (ROC) curve. Results: The correlation coefficient of FibroTouch and ARFI was 0.746 (P<0.01). FibroTouch and ARFI were significantly correlated with pathological stage determined by liver biopsy(r=0.705 and 0.727, all P<0.01). When 8.4 kPa was taken as the cut-off value of LSM and 1.49 m/s was taken as the cut-off value of VTQ, the areas under ROC (AUCs) were 0.857 and 0.836 (P>0.05) in diagnosis of fibrosis S≥2 stage; when 10.8 kPa of LSM and 1.49 m/s of VTQ were used as cut-off values, the AUCs were 0.872 and 0.881 (P>0.05) in diagnosis of S≥3 stage; when 12.3 kPa of LSM and 1.81m/s of VTQ were used as cut-off values, the AUCs were 0.875 and 0.888 (P>0.05) in diagnosis of S=4 stage. Conclusion: Both FibroTouch and ARFI can be effectively used in evaluation of liver fibrosis in patients with chronic hepatitis B.

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

Objective

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

Materials and Methods

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

Results

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

Conclusion

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

Non-invasive assessment of liver fibrosis in patients with alcoholic liver disease using acoustic radiation force impulse elastography

OBJECTIVES

To investigate the diagnostic performance of the acoustic radiation force impulse (ARFI) elastography for the assessment of the liver fibrosis in alcoholic liver disease (ALD).

METHODS

We included 112 patients with ALD in whom liver biopsy, ARFI elastography, and aspartate-to-platelet ratio index (APRI) measurements were performed.

RESULTS

ARFI elastography correlated significantly with histological fibrosis (r = 0.685, P < 0.001) in patients with ALD. The diagnostic accuracies expressed as areas under receiver operating characteristic (AUROC) curves for ARFI elastography and APRI were 0.846 and 0.763 for the diagnosis of significant fibrosis (S ≥ 2), 0.875 and 0.688 for the diagnosis of severe fibrosis (S ≥ 3), and 0.893 and 0.648 for the diagnosis of liver cirrhosis, respectively. The AUROC values of ARFI elastography were significantly better than those of APRI for predicting severe fibrosis (P = 0.02) and cirrhosis (P = 0.04). The optimum cutoff values for ARFI elastography were 1.33 m/s for S ≥ 2, 1.40 m/s for S ≥ 3, and 1.65 m/s for S = 4 in patients with elevated alanine aminotransferase (ALT) levels; these decreased to 1.24 m/s for S ≥ 2, 1.27 m/s for S ≥ 3, and 1.41 m/s for S = 4 in patients with normal ALT.

CONCLUSION

ARFI elastography is an acceptable method for predicting the severity of fibrosis in patients with ALD. ARFI elastography is influenced by elevated aminotransferase levels in ALD.

Ultrasound-based elastography for the diagnosis of portal hypertension in cirrhotics

Progressive fibrosis is encountered in almost all chronic liver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered the reference method for staging the severity of fibrosis, but due to its drawbacks (inter and intra-observer variability, sampling errors, unequal distribution of fibrosis in the liver, and risk of complications and even death), non-invasive methods were developed to assess fibrosis (serologic and elastographic). Elastographic methods can be ultrasound-based or magnetic resonance imaging-based. All ultrasound-based elastographic methods are valuable for the early diagnosis of cirrhosis, especially transient elastography (TE) and acoustic radiation force impulse (ARFI) elastography, which have similar sensitivities and specificities, although ARFI has better feasibility. TE is a promising method for predicting portal hypertension in cirrhotic patients, but it cannot replace upper digestive endoscopy. The diagnostic accuracy of using ARFI in the liver to predict portal hypertension in cirrhotic patients is debatable, with controversial results in published studies. The accuracy of ARFI elastography may be significantly increased if spleen stiffness is assessed, either alone or in combination with liver stiffness and other parameters. Two-dimensional shear-wave elastography, the ElastPQ technique and strain elastography all need to be evaluated as predictors of portal hypertension.

Normal values of spleen stiffness in healthy children assessed by acoustic radiation force impulse imaging (ARFI): comparison between two ultrasound transducers

BACKGROUND

Portal hypertension, a major complication of hepatic fibrosis, can affect the stiffness of the spleen.

OBJECTIVE

To suggest normal values of spleen stiffness determined by acoustic radiation force impulse imaging in healthy children and to compare measurements using two different US probes.

MATERIALS AND METHODS

In a prospective study, 60 healthy children between 1 day and 14 years of age were assigned to four age groups with 15 children in each. Measurements were performed using two transducers (convex 4C1 and linear 9L4), and 10 measurements were obtained in each child, 5 with each probe.

RESULTS

The mean splenic shear wave velocities were 2.17 m/s (SD 0.35, 95% CI 2.08-2.26) with the 4C1 probe and 2.15 m/s (SD 0.23, 95% CI 2.09-2.21) with the 9L4 probe (not significant).

CONCLUSION

We found normal values for spleen stiffness with no difference in the mean values obtained using two types of US transducers, but with higher variability using a convex compared to a linear transducer.

Acoustic radiation force impulse elastography of the liver in healthy patients: test location, reference range and influence of gender and body mass index

The objective of this study was to evaluate the best test location and study factors associated with acoustic radiation force impulse (ARFI) elastography measurements in healthy individuals. When ARFI elastography was performed on 68 healthy patients after controlling for all known test condition factors except segmental location, the median shear wave velocities (SWVs) derived from five valid measurements in the area between S5 and S8 in patients in the supine position had a significantly lower mean and the narrowest 95% confidence interval, followed by those for the S8 supine and S8 semidecubitus locations (p = 0.045). Analysis of mean SWVs revealed similar, although statistically insignificant, findings (p = 0.078). Male patients had significantly higher median SWVs (p = 0.0073) and mean SWVs (p = 0.0043) than female patients. Patients with body mass indexes >22 had significantly lower median SWVs (p = 0.0033) and mean SWVs (p = 0.0008) than those with body mass indexes ≤22. S5/8 supine was the better test location for ARFI. The reference ranges for median and mean SWV were 0.81-1.27 and 0.82-1.27 m/s, respectively. Gender and body mass index, but not age, were the significant factors associated with ARFI SWV values.

Usefulness of evaluating hepatic elasticity using artificial acoustic radiation force ultrasonography before hepatectomy

AIM

To evaluate hepatic fibrosis and tumor diagnosis preoperatively, we investigated the elasticity calculated by the new parameter of ultrasonography, acoustic radiation force impulse (ARFI).

METHODS

We examined ARFI of the non-tumorous right and left lateral liver and in the tumor by push pulse of probe in 95 patients with hepatic malignancies undergoing hepatectomy. Measurement of ARFI as hepatic stiffness was indicated as the Vs (m/s).

RESULTS

Measuring the Vs in the non-tumor region was achieved in the right liver in 99% and at the left lateral liver in 94%. The Vs in the right liver was significantly lower than in the left lateral liver, and the Vs of the liver tumor was significantly higher than in the non-tumorous liver. The Vs in the right and left lateral liver was correlated with the platelet count, aspartate aminotransferase, fibrotic indices and indocyanine green test. The Vs in the right liver was significantly correlated with the fibrotic marker or index. The Vs of liver cirrhosis and histological stage 4 in the right and left liver was significantly the highest compared to the others. The Vs in the right liver showed a high area under the receiver-operator curve value predicting histological fibrosis. The Vs in the right was significantly correlated with blood loss and postoperative complications, particularly uncontrolled ascites.

CONCLUSION

Non-invasive ARFI imaging elastography is useful in evaluating impaired liver function or in the differential diagnosis of liver malignancies, highly hepatic fibrosis and in predicting posthepatectomy morbidity.

Elastography in clinical practice

Elastography is a new technique that evaluates tissue stiffness. There are two elastography methods, strain and shear wave elastography. Both techniques are being used to evaluate a wide range of applications in medical imaging. Elastography of breast masses and prostates have been shown to have high accuracy for characterizing masses and can significantly decrease the need for biopsies. Shear wave elastography has been shown to be able to detect and grade liver fibrosis and may decrease the need for liver biopsy. Evaluation of other organs is still preliminary. This article reviews the principles of elastography and its potential clinical applications.

Acoustic radiation force impulse elastography and serum fibrosis markers in chronic hepatitis C

OBJECTIVE

Liver biopsy (LB) remains the gold standard for the assessment of liver fibrosis, although it is invasive and can have complications. The present study compares several noninvasive methods of fibrosis assessment in chronic hepatitis C (CHC), including acoustic radiation force impulse (ARFI) elastography, aspartate aminotransferase:platelet ratio index (APRI), Forns, FIB-4, and King scores versus percutaneous LB.

MATERIAL AND METHODS

This prospective study enrolled 51 untreated CHC patients. Biological tests necessary for the calculation of the scores (according to the classic formulas) were performed within a week of LB. The time interval between LB and tissue stiffness, assessed according to the Metavir score, was <6 months. Cutoff values were determined using area under receiver-operating characteristic curves (AUROC).

RESULTS

The best test for predicting significant fibrosis (F ≥2 Metavir) was ARFI elastography with an AUROC of 0.90, followed by FIB-4 (AUROC = 0.86), King (AUROC = 0.85), Forns (AUROC = 0.84), and APRI (AUROC = 0.82). For a cutoff of 1.31 m/s, ARFI had 89.3% sensitivity (Se) and 87% specificity (Sp). The best test for predicting cirrhosis was ARFI elastography with an AUROC of 0.98, followed by FIB-4 (AUROC = 0.94), King (AUROC = 0.90), APRI (AUROC = 0.82), and Forns (AUROC = 0.81). For a cutoff of 1.95 m/s, ARFI had 100% Se and 95.2% Sp.

CONCLUSION

ARFI elastography had very good accuracy for the assessment of liver fibrosis. It was more effective than APRI, Forns, King, and FIB-4 scores for the prediction of significant fibrosis and cirrhosis in CHC patients.

Acoustic Radiation Force Impulse (ARFI) and Transient Elastography (TE) for evaluation of liver fibrosis in HIV-HCV co-infected patients

BACKGROUND

Transient elastography (TE) is widely used for non-invasive assessment of liver fibrosis in HIV-HCV co-infected patients. TE, however, cannot determine liver morphology. Acoustic radiation force impulse (ARFI) imaging is a novel procedure enabling assessment of liver fibrosis during a conventional ultrasonographic examination. This study evaluated the correlation between liver fibrosis measurements by TE and ARFI.

METHODS

Each of 46 HIV-HCV patients underwent both ARFI and TE within 6 months. Patients were evaluated by the "equivalent METAVIR" scoring system, using previously established cut-off values. Agreements between the ARFI and TE scores were estimated by Kappa coefficients, with Kappa values ≥0.40, ≥0.60, and ≥0.80 defined as moderate, good and very good agreement, respectively.

RESULTS

ARFI and TE yielded "Equivalent Metavir" fibrosis scores of F1 in 26 and 31 patients, respectively; F2 in nine and seven, respectively; F3 in three and two, respectively; and F4 in eight and six, respectively. The two methods showed very good agreement in predicting overall stages [Kappa = 0.82] and for F ≥3 [Kappa = 0.80] and moderate agreement in predicting significant fibrosis F ≥2 [Kappa = 0.50]. Morphologic ultrasound analysis concomitant to ARFI detected two hepatocarcinomas.

CONCLUSIONS

ARFI showed promising results in the non-invasive assessment of liver fibrosis in HIV-HCV patients, with liver fibrosis staging similar to that of TE. Moreover, ARFI can assess morphology and fibrosis during the same session.

Ultrasound in chronic liver disease

Background

With the high prevalence of diffuse liver disease there is a strong clinical need for noninvasive detection and grading of fibrosis and steatosis as well as detection of complications.

Methods

B-mode ultrasound supplemented by portal system Doppler and contrast-enhanced ultrasound are the principal techniques in the assessment of liver parenchyma and portal venous hypertension and in hepatocellular carcinoma surveillance.

Results

Fibrosis can be detected and staged with reasonable accuracy using Transient Elastography and Acoustic Radiation Force Imaging. Newer elastography techniques are emerging that are undergoing validation and may further improve accuracy. Ultrasound grading of hepatic steatosis currently is predominantly qualitative.

Conclusion

A summary of methods including B-mode, Doppler, contrast-enhanced ultrasound and various elastography techniques, and their current performance in assessing the liver, is provided.

Teaching Points

• Diffuse liver disease is becoming more prevalent and there is a strong clinical need for noninvasive detection.

• Portal hypertension can be best diagnosed by demonstrating portosystemic collateral venous flow.

• B-mode US is the principal US technique supplemented by portal system Doppler.

• B-mode US is relied upon in HCC surveillance, and CEUS is useful in the evaluation of possible HCC.

• Fibrosis can be detected and staged with reasonable accuracy using TE and ARFI.

• US detection of steatosis is currently reasonably accurate but grading of severity is of limited accuracy.

The acoustic radiation force impulse elastography evaluation of liver fibrosis in posttransplantation dysfunction of living donor liver transplantation

BACKGROUND

The acoustic radiation force impulse elastography (ARFI) is a new technology of elastography integrated into B-mode ultrasonography. It has been a reliable method to evaluate liver fibrosis of chronic liver disease in recent years, but less applied in the posttransplantation liver. The aim of the study was to evaluate liver fibrosis by the ARFI with correlation of pathological stages in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

From August 2010 to August 2012, there were 57 LDLT patients with liver biopsy (LB) due to posttransplantation dysfunction; all patients also received posttransplantation ARFI liver stiffness measurement (LSM) after transplantation for liver fibrosis staging. The ARFI elastography was performed using a Siemens Acuson S2000 ultrasound system with 4V1 transducers (Acusion, Siemens Medical Systems Co. Ltd. Erlangen, Germany). The ARFI LSM value was presented by shear wave velocity (SWV, m/s). The fibrosis staging as F0 to F4 was in accordance with the Metavir scoring system.

RESULTS

A total of 57 patients had both posttransplantation LB and effective ARFI fibrosis staging for correlation. The ARFI LSM value increased with severity of liver fibrosis and had significant linear correlation with the results of histological fibrosis staging. The ARFI LSM sensitivities (Se), specificities (Sp), and cutoff values based on receiver-operator characteristic curve were F0: 0.75 m/s (Se: 93.8%, Sp: 4%), F1: 1.06 m/s (Se: 95.5%, Sp: 25.7%), F2: 1.81 m/s (Se: 50%, Sp: 83.6%) and F3: 2.33 m/s (Se: 100%, Sp: 92.9%). Predictive value of ARFI LSM reported a significant difference between early fibrosis stage (F0-F1) and advanced fibrosis stage (F ≧ 2) (P < .05).

CONCLUSION

In this study, ARFI demonstrated a strong linear correlation and severity of liver fibrosis with LB pathologic staging. ARFI can be an alternative and compensatory method for frequent LB in the posttransplantation liver.

Non-invasive diagnosis of liver fibrosis in chronic hepatitis C

Assessment of liver fibrosis in chronic hepatitis C virus (HCV) infection is considered a relevant part of patient care and key for decision making. Although liver biopsy has been considered the gold standard for staging liver fibrosis, it is an invasive technique and subject to sampling errors and significant intra- and inter-observer variability. Over the last decade, several noninvasive markers were proposed for liver fibrosis diagnosis in chronic HCV infection, with variable performance. Besides the clear advantage of being noninvasive, a more objective interpretation of test results may overcome the mentioned intra- and inter-observer variability of liver biopsy. In addition, these tests can theoretically offer a more accurate view of fibrogenic events occurring in the entire liver with the advantage of providing frequent fibrosis evaluation without additional risk. However, in general, these tests show low accuracy in discriminating between intermediate stages of fibrosis and may be influenced by several hepatic and extra-hepatic conditions. These methods are either serum markers (usually combined in a mathematical model) or imaging modalities that can be used separately or combined in algorithms to improve accuracy. In this review we will discuss the different noninvasive methods that are currently available for the evaluation of liver fibrosis in chronic hepatitis C, their advantages, limitations and application in clinical practice.

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.

Acoustic radiation force impulse of the liver

Acoustic radiation force impulse (ARFI) imaging is a new and promising ultrasound-based diagnostic technique that, evaluating the wave propagation speed, allows the assessment of the tissue stiffness. ARFI is implemented in the ultrasound scanner. By short-duration acoustic radiation forces (less than 1 ms), localized displacements are generated in a selected region of interest not requiring any external compression so reducing the operator dependency. The generated wave scan provides qualitative or quantitative (wave velocity values) responses. Several non-invasive methods for assessing the staging of fibrosis are used, in order to avoid liver biopsy. Liver function tests and transient elastography are non-invasive, sensitive and accurate tools for the assessment of liver fibrosis and for the discrimination between cirrhotic and non-cirrhotic liver. Many published studies analyse ARFI performance and feasibility in studying diffuse liver diseases and compare them to other diagnostic imaging modalities such as conventional ultrasonography and transient elastography. Solid focal liver lesions, both benign and malignant, are common findings during abdominal examinations. The accurate characterization and differential diagnosis are important aims of all the imaging modalities available today. Only few papers describe the application of ARFI technology in the study of solid focal liver lesions, with different results. In the present study, the existing literature, to the best of our knowledge, about ARFI application on diffuse and focal liver pathology has been evaluated and results and statistical analyses have been compared, bringing to the conclusion that ARFI can be used in the study of the liver with similar accuracy as transient elastography in diagnosing significant fibrosis or cirrhosis and has got some advantages in respect to transient elastography since it does not require separate equipment, better displays anatomical structures and measurements can be successfully carried out almost in every patient.

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.

Comparative study concerning the value of acoustic radiation force impulse elastography (ARFI) in comparison with transient elastography (TE) for the assessment of liver fibrosis in patients with chronic hepatitis B and C

Our aim was to compare liver stiffness (LS) measurements by means of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in patients with chronic hepatitis B and C, according to the severity of fibrosis. We also compared the correlation strength of ARFI and TE measurements with liver fibrosis. We included 53 patients with hepatitis B and 107 with hepatitis C in which liver biopsy, ARFI and TE measurements were performed in the same session. The mean LS values measured with ARFI were similar in patients with chronic hepatitis B and C and depended on the stage of fibrosis. The correlation strength of LS measurements by ARFI and by TE with fibrosis was similar in chronic hepatitis B and C patients. In conclusion, for the same stage of fibrosis, the mean LS values by ARFI were similar in patients with chronic hepatitis B and C. ARFI had similar predictive value with TE in both chronic viral hepatitis.