Liver elasticity in NASH patients evaluated with real-time elastography (RTE)

Assessing the Utility of Acoustic Radiation Force Impulse in the Evaluation of Non-Alcoholic Fatty Liver Disease with Severe Obesity or Steatosis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) encompasses a heterogeneous spectrum ranging from simple steatosis to fibrosis and cirrhosis. Fibrosis, associated with long-term overall mortality and liver-related events, requires evaluation. Traditionally, liver biopsy has been the gold standard for diagnosing fibrosis. However, its invasive nature, potential complications, and sampling variability limit widespread use. Consequently, various non-invasive tests have been developed as alternatives for diagnosing fibrosis in NAFLD patients.

AIM

This study aimed to compare the accuracy of non-invasive tests (NITs) and evaluate the diagnostic accuracy of acoustic radiation force impulse (ARFI), one of the point shear wave techniques, compared to conventional methods, assessing its effective role in diagnosis.

METHODS

This is a retrospective study; a total of 136 patients diagnosed with fatty liver disease through ultrasonography were enrolled. The anthropometric data of the patients were collected on the day of admission and blood tests, measurements of ARFI, and a point shear test were conducted using abdominal ultrasound; a biopsy was performed the following day. In addition, we calculated the aspartate aminotransferase-to-platelet ratio index (APRI) index based on four factors (FIB-4) and the NAFLD fibrosis score (NFS). Subsequently, we assessed the diagnostic accuracy of NITs within various subgroups based on the extent of obesity, steatosis, or NAFLD activity score.

RESULTS

ARFI has been shown to have the highest diagnostic value among various NITs, with AUROC values of 0.832, 0.794, 0.767, and 0.696 for ARFI, APRI, FIB-4, and NFS, respectively. In the morbidly obese subgroup, the AUROC values of ARFI, APRI, FIB-4, and NFS were 0.805, 0.769, 0.736, and 0.674. In the group with severe steatosis or non-alcoholic steatohepatitis (NASH), the AUROC values were 0.679, 0.596, 0.661, and 0.612, respectively, for severe steatosis and 0.789, 0.696, 0.751, and 0.691, respectively, for NASH.

CONCLUSIONS

In conclusion, ARFI is not affected by various factors and maintains diagnostic accuracy compared to serum NITs. Therefore, we can recommend ARFI as a valuable diagnostic test to screen for advanced fibrosis in patients with NAFLD.

Comparison of strain elastography and shear wave elastography in diagnosis of fibrosis in nonalcoholic fatty liver disease

PURPOSE

To reveal the ability of S-Map strain elastography to diagnose fibrosis in nonalcoholic fatty liver disease (NAFLD) and to compare its diagnostic ability with that of shear wave elastography (SWE).

METHODS

Participants were patients with NAFLD who were scheduled to undergo liver biopsy at our institution between 2015 and 2019. A GE Healthcare LOGIQ E9 ultrasound system was used. For S-Map, the right lobe of the liver was visualized in the section where the heartbeat was detected by right intercostal scanning, a 4 × 2-cm region of interest (ROI) was defined at 5 cm from the liver surface, and ROI strain images were acquired. Measurements were repeated six times, with the average taken as the S-Map value. Correlations of S-Map and SWE values with fibrosis stage determined by liver biopsy were analyzed using multiple comparisons. The diagnostic performance of S-Map for fibrosis staging was assessed using receiver operating characteristic curves.

RESULTS

In total, 107 patients (65 men, 42 women; mean age 51 ± 14 years) were analyzed. The S-Map value by fibrosis stage was 34.4 ± 10.9 for F0, 32.9 ± 9.1 for F1, 29.5 ± 5.6 for F2, 26.7 ± 6.0 for F3, and 22.8 ± 4.19 for F4. By fibrosis stage, the SWE value was 1.27 ± 0.25 for F0, 1.39 ± 0.20 for F1, 1.59 ± 0.20 for F2, 1.64 ± 0.17 for F3, and 1.88 ± 0.19 for F4. The diagnostic performance of S-Map (measured by area under the curve) was 0.75 for F2, 0.80 for F3, and 0.85 for F4. The diagnostic performance of SWE (measured by area under the curve) was 0.88 for F2, 0.87 for F3, and 0.92 for F4.

CONCLUSION

S-Map strain elastography was inferior to SWE in terms of ability to diagnose fibrosis in NAFLD.

Is There a Relationship between the Elasticity of Brain Tumors, Changes in Diffusion Tensor Imaging, and Histological Findings? A Pilot Study Using Intraoperative Ultrasound Elastography

Intraoperative ultrasound elastography (IOUS-E) is a novel image modality applied in brain tumor assessment. However, the potential links between elastographic findings and other histological and neuroimaging features are unknown. This study aims to find associations between brain tumor elasticity, diffusion tensor imaging (DTI) metrics, and cell proliferation. A retrospective study was conducted to analyze consecutively admitted patients who underwent craniotomy for supratentorial brain tumors between March 2018 and February 2020. Patients evaluated by IOUS-E and preoperative DTI were included. A semi-quantitative analysis was performed to calculate the mean tissue elasticity (MTE). Diffusion coefficients and the tumor proliferation index by Ki-67 were registered. Relationships between the continuous variables were determined using the Spearman ρ test. A predictive model was developed based on non-linear regression using the MTE as the dependent variable. Forty patients were evaluated. The pathologic diagnoses were as follows: 21 high-grade gliomas (HGG); 9 low-grade gliomas (LGG); and 10 meningiomas. Cases with a proliferation index of less than 10% had significantly higher medians of MTE (110.34 vs. 79.99, p < 0.001) and fractional anisotropy (FA) (0.24 vs. 0.19, p = 0.020). We found a strong positive correlation between MTE and FA (r_s (38) = 0.91, p < 0.001). A cubic spline non-linear regression model was obtained to predict tumoral MTE from FA (R² = 0.78, p < 0.001). According to our results, tumor elasticity is associated with histopathological and DTI-derived metrics. These findings support the usefulness of IOUS-E as a complementary tool in brain tumor surgery.

Meningioma Consistency Can Be Defined by Combining the Radiomic Features of Magnetic Resonance Imaging and Ultrasound Elastography. A Pilot Study Using Machine Learning Classifiers

BACKGROUND

The consistency of meningioma is a factor that may influence surgical planning and the extent of resection. The aim of our study is to develop a predictive model of tumor consistency using the radiomic features of preoperative magnetic resonance imaging and the tumor elasticity measured by intraoperative ultrasound elastography (IOUS-E) as a reference parameter.

METHODS

A retrospective analysis was performed on supratentorial meningiomas that were operated on between March 2018 and July 2020. Cases with IOUS-E studies were included. A semiquantitative analysis of elastograms was used to define the meningioma consistency. MRIs were preprocessed before extracting radiomic features. Predictive models were built using a combination of feature selection filters and machine learning algorithms: logistic regression, Naive Bayes, k-nearest neighbors, Random Forest, Support Vector Machine, and Neural Network. A stratified 5-fold cross-validation was performed. Then, models were evaluated using the area under the curve and classification accuracy.

RESULTS

Eighteen patients were available for analysis. Meningiomas were classified as hard or soft according to a mean tissue elasticity threshold of 120. The best-ranked radiomic features were obtained from T1-weighted post-contrast, apparent diffusion coefficient map, and T2-weighted images. The combination of Information Gain and ReliefF filters with the Naive Bayes algorithm resulted in an area under the curve of 0.961 and classification accuracy of 94%.

CONCLUSIONS

We have developed a high-precision classification model that is capable of predicting consistency of meningiomas based on the radiomic features in preoperative magnetic resonance imaging (T2-weighted, T1-weighted post-contrast, and apparent diffusion coefficient map).

Intraoperative Ultrasonographic Elastography: A Semi-Quantitative Analysis of Brain Tumor Elasticity Patterns and Peritumoral Region

BACKGROUND

Ultrasonographic elastography imaging visualizes the elastic properties of tissues to distinguish pathologic and healthy areas. Real-time elastography measures relative tissue hardness by evaluating changes in local strain in response to external forces.

OBJECTIVE

We aimed to determine the elastographic patterns of different brain tumor types and establish differences between their peritumoral regions.

METHODS

We prospectively enrolled patients undergoing craniotomy along with intraoperative ultrasonographic elastography for supratentorial brain tumors in March 2018-May 2019. The elastograms were semi-quantitatively analyzed offline based on the mean tissue elasticity of the tumors, peritumoral regions, and healthy parenchyma.

RESULTS

We examined 37 lesions in 36 patients. The pathologic diagnoses comprised 11 meningiomas (29.7%), 4 low-grade gliomas (LGGs; 10.8%), 16 high-grade gliomas (HGGs; 43.2%), and 6 metastases (16.2%). The median MTE values observed after manual segmentation of the whole tumor were as follows: meningiomas, 119.9 (36.6); HGGs, 77.9 (18.9); LGGs, 91 (19.5); metastases, 103.9 (35.6); tumor types significantly differed (H = 18.2; P < 0.001). The peritumoral MTE values were as follows: meningiomas, 120.1 (36.3); HGGs, 86.3 (20.9); LGGs, 94.8 (7.38); and metastases, 116.3 (22). The intergroup differences were significant (H = 17.43; P < 0.001). Using receiver operating characteristic curves, we obtained an optimal cutoff point of 92.22 (whole tumors) and 109.6 (peritumoral regions). Values below these cutoff points were correlated with a high probability of being a glioma.

CONCLUSIONS

We objectively describe the elastographic patterns of different types of brain tumors (i.e., gliomas, metastases, and meningiomas). We have identified differences in both the tumors and the peritumoral areas of these histologic types.

Could semiquantitative analysis of real-time ultrasound elastography distinguish more liver parenchyma alterations of nonalcoholic fatty liver disease in patients with polycystic ovary syndrome?

OBJECTIVE

Nonalcoholic fatty liver disease is the commonest diffuse liver disease, of which women with polycystic ovary syndrome are at an increased risk. The aim of the present study was to assess the diagnostic value of the semiquantitative strain parameters of real-time ultrasound elastography for nonalcoholic fatty liver disease in patients with polycystic ovary syndrome.

SUBJECTS AND METHODS

Thirty-five polycystic ovary syndrome patients with nonalcoholic fatty liver disease, 70 polycystic ovary syndrome patients without nonalcoholic fatty liver disease, and 70 healthy female controls of reproductive age were included. All participants underwent ultrasonic examination and semiquantitative analysis of real-time ultrasound elastography of the liver.

RESULTS

Main semi quantitative strain parameters, such as average strain value, differed significantly among groups polycystic ovary syndrome with nonalcoholic fatty liver disease, polycystic ovary syndrome without nonalcoholic fatty liver disease, and control (87.02 ± 10.16 vs. 96.31 ± 11.44 vs. 104.49 ± 7.28, p < 0.001). Clinical and laboratory parameters differed significantly between the two subgroups with low or high average strain value. For diagnostic value of average strain value for elevated aminotransferase, the area under the curve was 0.808 (range 0.721-0.895). In multiple linear regression analysis, polycystic ovary syndrome, waist circumference, and metabolic syndrome were stand-alone independent factors associated with average strain value among subjects without nonalcoholic fatty liver disease.

CONCLUSION

Semiquantitative real-time ultrasound elastography analysis could distinguish liver parenchyma alterations in patients with polycystic ovary syndrome more sensitively. The diagnostic value of the proposed method for nonalcoholic fatty liver disease need further research.

Ultrasound/Elastography techniques, lipidomic and blood markers compared to Magnetic Resonance Imaging in non-alcoholic fatty liver disease adults

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) may progress to steatohepatitis, cirrhosis and complicated hepatocellular carcinoma with defined differential symptoms and manifestations.

OBJECTIVE

To evaluate the fatty liver status by several validated approaches and to compare imaging techniques, lipidomic and routine blood markers with magnetic resonance imaging in adults subjects with non-alcoholic fatty liver disease.

MATERIALS AND METHODS

A total of 127 overweight/obese with NAFLD, were parallelly assessed by Magnetic Resonance Imaging (MRI), ultrasonography, transient elastography and a validated metabolomic designed test to diagnose NAFLD in this cross-sectional study. Body composition (DXA), hepatic related biochemical measurements as well as the Fatty Liver Index (FLI) were evaluated. This study was registered as FLiO: Fatty Liver in Obesity study; NCT03183193.

RESULTS

The subjects with more severe liver disease were found to have worse metabolic parameters. Positive associations between MRI with inflammatory and insulin biomarkers were found. A linear regression model including ALT, RBP4 and HOMA-IR was able to explain 40.9% of the variability in fat content by MRI. In ROC analyses a combination panel formed of ALT, HOMA-IR and RBP4 followed by ultrasonography, ALT and metabolomic test showed the major predictive ability (77.3%, 74.6%, 74.3% and 71.1%, respectively) for liver fat content.

CONCLUSIONS

A panel combination including routine blood markers linked to insulin resistance showed highest associations with MRI considered as a gold standard for determining liver fat content. This combination of tests can facilitate the diagnosis of early stages of non-alcoholic liver disease thereby avoiding other invasive and expensive methods.

Ultrasonic Perfluorohexane-Loaded Monocyte Imaging: Toward a Minimally Invasive Technique for Selective Detection of Liver Inflammation in Fatty Liver Disease

OBJECTIVES

To investigate the utility of ultrasonic (US) perfluorohexane (PFH)-loaded monocyte imaging for detection of liver inflammation in fatty liver disease.

METHODS

C57Bl6 mice were injected intraperitoneally with tumor necrosis factor α and assessed by US PFH-loaded monocyte imaging 3 hours later. Echogenic monocytes were injected intravenously, leading to a transient increase in liver tissue intensity on a US perfusion scan. The contrast wash-out time constant was hypothesized to reflect the degree of inflammation. Next, we evaluated US PFH-loaded monocyte imaging in Ldlr^-/- mice fed a 1-week high-fat/high-cholesterol diet as model for early developing nonalcoholic steatohepatitis. Adjunct analyses included tissue markers of liver inflammation.

RESULTS

Tumor necrosis factor α-injected mice showed a reduced wash-out time constant (mean ± SEM, 0.013 ± 0.003; n = 8) compared to controls (0.054 ± 0.009; n = 7; P = .0006), indicative of increased inflammatory adhesion molecule expression on the endothelium. The Ldlr^-/- mice fed the high-fat/high-cholesterol diet showed liver inflammation, as reflected by increased (3- to 4-fold) infiltration of inflammatory cells and increased (3- to 4-fold) gene expression of tumor necrosis factor α, integrin αM, intracellular adhesion molecule, and vascular cell adhesion molecule. However, in these mice, no difference was detected in the wash-out time constant as assessed by US PFH-loaded monocyte imaging (high-fat/high-cholesterol, 0.050 ± 0.017; n = 5; chow, 0.048 ± 0.006; n = 6; P = .91).

CONCLUSIONS

Our results indicate that US PFH-loaded monocyte imaging is able to detect vascularly expressed inflammatory adhesion molecules in the mouse liver on direct endothelial stimulation. However, in our mouse model of early developing nonalcoholic steatohepatitis, we did not detect inflammation by this method, which may suggest that the time-dependent relationship between parenchymal and endothelial inflammation remains a fundamental issue to be addressed.

Machine-learning-based classification of real-time tissue elastography for hepatic fibrosis in patients with chronic hepatitis B

Hepatic fibrosis is a common middle stage of the pathological processes of chronic liver diseases. Clinical intervention during the early stages of hepatic fibrosis can slow the development of liver cirrhosis and reduce the risk of developing liver cancer. Performing a liver biopsy, the gold standard for viral liver disease management, has drawbacks such as invasiveness and a relatively high sampling error rate. Real-time tissue elastography (RTE), one of the most recently developed technologies, might be promising imaging technology because it is both noninvasive and provides accurate assessments of hepatic fibrosis. However, determining the stage of liver fibrosis from RTE images in a clinic is a challenging task. In this study, in contrast to the previous liver fibrosis index (LFI) method, which predicts the stage of diagnosis using RTE images and multiple regression analysis, we employed four classical classifiers (i.e., Support Vector Machine, Naïve Bayes, Random Forest and K-Nearest Neighbor) to build a decision-support system to improve the hepatitis B stage diagnosis performance. Eleven RTE image features were obtained from 513 subjects who underwent liver biopsies in this multicenter collaborative research. The experimental results showed that the adopted classifiers significantly outperformed the LFI method and that the Random Forest(RF) classifier provided the highest average accuracy among the four machine algorithms. This result suggests that sophisticated machine-learning methods can be powerful tools for evaluating the stage of hepatic fibrosis and show promise for clinical applications.

Non-invasive imaging techniques in assessing non-alcoholic fatty liver disease: a current status of available methods

Non-alcoholic fatty liver disease (NAFLD) is an ailment affecting and increasing a number of people worldwide diagnosed via non-invasive imaging techniques, at a time when a minimum harm caused by medical procedures is rightfully emphasized, more sought after, than ever before. Liver steatosis should not be taken lightly even if its evolution is largely benign as it has the potential to develop into non-alcoholic steatohepatitis (NASH) or even more concerning, hepatic cirrhosis, and hepatocellular carcinoma (HCC). Traditionally, liver biopsy has been the standard for diagnosing this particular liver disease, but nowadays, a consistent number of imagistic methods are available for diagnosing hepatosteatosis and choosing the one appropriate to the clinical context is the key. Although different in sensitivity and specificity when it comes to determining the hepatic fat fraction (FF), these imaging techniques possessing a diverse availability, operating difficulty, cost, and reproducibility are invaluable to any modern physician. Ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), elastography, and spectroscopy will be discussed in order to lay out the advantages and disadvantages of their diagnostic potential and application.

Although imagistics has given physicians a valuable insight into the means of managing NAFLD, the current methods are far from perfect, but given the time, they will surely be improved and the use of liver biopsy will be completely removed.

Imaging biomarkers for steatohepatitis and fibrosis detection in non-alcoholic fatty liver disease

There is a need, in NAFLD management, to develop non-invasive methods to detect steatohepatitis (NASH) and to predict advanced fibrosis stages. We evaluated a tool based on optical analysis of liver magnetic resonance images (MRI) as biomarkers for NASH and fibrosis detection by investigating patients with biopsy-proven NAFLD who underwent magnetic resonance (MR) protocols using 1.5T General Electric (GE) or Philips devices. Two imaging biomarkers (NASHMRI and FibroMRI) were developed, standardised and validated using area under the receiver operating characteristic curve (AUROC) analysis. The results indicated NASHMRI diagnostic accuracy for steatohepatitis detection was 0.83 (95% CI: 0.73–0.93) and FibroMRI diagnostic accuracy for significant fibrosis determination was 0.85 (95% CI: 0.77–0.94). These findings were independent of the MR system used. We conclude that optical analysis of MRI has high potential to define non-invasive imaging biomarkers for the detection of steatohepatitis (NASHMRI) and the prediction of significant fibrosis (FibroMRI) in NAFLD patients.

Diagnostic value of optimised real-time sonoelastography in the assessment of liver fibrosis in chronic hepatitis B and C

Aim

To optimise the method of real-time elastography (RTE) in the assessment of liver fibrosis using an in-house prepared method for elastogram analysis, as well as a semiquantitative analysis based on newly introduced parameters.

Material and methods

Sonoelastography was performed in 94 patients with various degrees of liver fibrosis and also in 25 healthy volunteers. As a reference method for diagnostic efficacy of sonoelastography-based parameters used for the assessment of fibrosis degree in patients with chronic B and C hepatitis, a liver biopsy was used. Patient’s elastograms were analysed using in-house prepared software, Pixel Count, calculating two semiquantitative parameters: mean stiffness fraction (MSF%) and intrinsic stiffness ratio (ISR).

Results

Statistically significant differences between distributions of the above presented parameters for different degrees of liver fibrosis were revealed. Indices of diagnostic efficacy for detection of significant liver fibrosis (F ≥ 2) using MSF% amounted to: sensitivity – 76%, specificity – 87% and ISR: 81% and 87%, respectively. Sensitivity of both parameters in detection of cirrhosis (F = 4) was equal to 88% and specificity amounted to: for MSF% – 84% and ISR – 86%. Interobserver reproducibility determined for both of the above parameters was high, intraclass correlation coefficients (ICC) were 0.91 for MSF% and 0.93 for ISR.

Conclusions

Real-time elastography applied in this study, using in-house prepared Pixel Count software, provided good reproducibility and diagnostic efficacy, especially specificity, in the assessment of liver fibrosis degree.

Can early hepatic fibrosis stages be discriminated by combining ultrasonic parameters?

In this study, we put forward a new approach to classify early stages of fibrosis based on a multiparametric characterization using backscatter ultrasonic signals. Ultrasonic parameters, such as backscatter coefficient (Bc), speed of sound (SoS), attenuation coefficient (Ac), mean scatterer spacing (MSS), and spectral slope (SS), have shown their potential to differentiate between healthy and pathologic samples in different organs (eye, breast, prostate, liver). Recently, our group looked into the characterization of stages of hepatic fibrosis using the parameters cited above. The results showed that none of them could individually distinguish between the different stages. Therefore, we explored a multiparametric approach by combining these parameters in two and three, to test their potential to discriminate between the stages of liver fibrosis: F0 (normal), F1, F3, and/without F4 (cirrhosis), according to METAVIR Score. Discriminant analysis showed that the most relevant individual parameter was Bc, followed by SoS, SS, MSS, and Ac. The combination of (Bc, SoS) along with the four stages was the best in differentiating between the stages of fibrosis and correctly classified 85% of the liver samples with a high level of significance (p<0.0001). Nevertheless, when taking into account only stages F0, F1, and F3, the discriminant analysis showed that the parameters (Bc, SoS) and (Bc, Ac) had a better classification (93%) with a high level of significance (p<0.0001). The combination of the three parameters (Bc, SoS, and Ac) led to a 100% correct classification. In conclusion, the current findings show that the multiparametric approach has great potential in differentiating between the stages of fibrosis, and thus could play an important role in the diagnosis and follow-up of hepatic fibrosis.

Non-invasive diagnostic approach to non-alcoholic fatty liver disease: current evidence and future perspectives

Non-alcoholic fatty liver disease is a new epidemic liver disease, thus, its early diagnosis and the identification of those patients with the worst prognosis is mandatory. Liver biopsy is still the diagnostic gold standard, even if it is associated to a significant rate of complications; moreover, the interpretation of histological samples is not always univocal. Several non-invasive alternative scores have been proposed for the diagnostic approach to non-alcoholic fatty liver disease. This article evaluates the performance of the currently available non-invasive diagnostic strategies. The authors also suggest a potential diagnostic algorithm, with two or more non-invasive techniques, to increase the overall accuracy for identifying patients with worst prognosis, and to minimize the recourse to liver biopsy.

Imaging methods for evaluation of liver fibrosis

Liver fibrosis is a development stage of various chronic liver diseases. Since liver fibrosis is still a reversible process, the development of irreversible cirrhosis can be delayed or prevented if the patient is early diagnosed and receives timely and effective treatment. Therefore, how to accurately, effectively and easily evaluate the severity of liver fibrosis remains a clinical problem to be solved. Ultrasound, CT and MRI are common examinations for hepatic lesions. Imaging examinations can non-invasively and accurately evaluate the degree of liver fibrosis. With the development and application of new imaging technologies, flexible technology has been widely applied in the assessment of liver fibrosis. This article reviews the application of various imaging modalities, especially elastic technology, for assessment of hepatic fibrosis.

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted.

RESULTS

Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822.

LIMITATIONS

A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments.

CONCLUSIONS

Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Minimally invasive percutaneous endovascular therapies in the management of complications of non-alcoholic fatty liver disease (NAFLD): A case report

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disorders from simple steatosis to inflammation leading to fibrosis, cirrhosis, and even hepatocellular carcinoma. With the progressive epidemics of obesity and diabetes, major risk factors in the development and pathogenesis of NAFLD, the prevalence of NAFLD and its associated complications including liver failure and hepatocellular carcinoma is expected to increase by 2030 with an enormous health and economic impact. We present a patient who developed Hepatocellular carcinoma (HCC) from nonalcoholic steatohepatitis (NASH) cirrhosis. Due to morbid obesity, she was not an optimal transplant candidate and was not initially listed. After attempts for lifestyle modifications failed to lead to weight reduction, a transarterial embolization of the left gastric artery was performed. This is the sixth such procedure in humans in literature. Subsequently she had a meaningful drop in BMI from 42 to 36 over the following 6 months ultimately leading to her being listed for transplant. During this time, the left hepatic HCC was treated with chemoembolization without evidence of recurrence. In this article, we wish to highlight the use of minimally invasive percutaneous endovascular therapies such as transarterial chemoembolization (TACE) in the comprehensive management of the NAFLD spectrum and percutaneous transarterial embolization of the left gastric artery (LGA), a novel method, for the management of obesity.

The Global Nonalcoholic Fatty Liver Disease Epidemic: What a Radiologist Needs to Know

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disorders from a benign steatosis to hepatocellular carcinoma (HCC). Metabolic syndrome, mainly obesity, plays an important role, both as an independent risk factor and in the pathogenesis of NAFLD. With the progressive epidemics of obesity and diabetes mellitus, the prevalence of NAFLD and its associated complications is expected to increase dramatically. Therapeutic strategies for treating NAFLD and metabolic syndrome, particularly obesity, are continuously being refined. Their goal is the prevention of NAFLD by the management of risk factors, prevention of progression of the disease, as well as management of complications, ultimately preventing morbidity and mortality. Optimal management of NAFLD and metabolic syndrome requires a multidisciplinary collaboration between the government as well as the health system including the nutritionist, primary care physician, radiologist, hepatologist, oncologist, and transplant surgeon. An awareness of the clinical presentation, risk factors, pathogenesis, diagnosis, and management is of paramount importance to a radiologist, both from the clinical perspective as well as from the imaging standpoint. With expertise in imaging modalities as well as minimally invasive percutaneous endovascular therapies, radiologists play an essential role in the comprehensive management, which is highlighted in this article, with cases from our practice. We also briefly discuss transarterial embolization of the left gastric artery (LGA), a novel method that promises to have an enormous potential in the minimally invasive management of obesity, with details of a case from our practice.

Importance of imaging and recent developments in diagnosis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease and is a major public health problem worldwide. It is a spectrum that includes simple steatosis, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Recently, NAFLD prevalence in children and adolescents has increased too. The increasing prevalence has resulted in NASH-related chronic liver disease. Therefore, early diagnosis and treatment is quite important. Although liver biopsy is still the gold standard for diagnosis and staging of NAFLD, particularly for the diagnosis of NASH, imaging methods such as ultrasonography, computed tomography, magnetic resonance imaging with chemical shift imaging and especially magnetic resonance spectroscopy and elastography have been increasingly approved as noninvasive alternative methods. The aim of this review is to analyze the diagnostic accuracy and limitations of the imaging methods and recent developments in the diagnosis of NAFLD.

Non-invasive methods for the diagnosis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease and includes simple steatosis and nonalcoholic steatohepatitis (NASH). Since NASH progresses to cirrhosis more frequently and increases liver-related and cardiovascular disease risk substantially more than simple steatosis, there is a great need to differentiate the two entities. Liver biopsy is the gold standard for the diagnosis of NAFLD but its disadvantages, including the risk of complications and sampling bias, stress the need for developing alternative diagnostic methods. Accordingly, several non-invasive markers have been evaluated for the diagnosis of simple steatosis and NASH, including both serological indices and imaging methods. The present review summarizes the current knowledge on the role of these markers in the diagnosis of NAFLD. Current data suggest that ultrasound and the fibrosis-4 score are probably the most appealing methods for detecting steatosis and for distinguishing NASH from simple steatosis, respectively, because of their low cost and relatively high accuracy. However, currently available methods, both serologic and imaging, cannot obviate the need for liver biopsy for diagnosing NASH due to their substantial false positive and false negative rates. Therefore, the current role of these methods is probably limited in patients who are unwilling or have contraindications for undergoing biopsy.

Measurement of liver stiffness as a non-invasive method for diagnosis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of liver disease worldwide. To detect early stages of NAFLD and start treatment or to monitor the changes in trials of new drugs, non-invasive diagnostic methods are needed, such as biochemical markers or liver stiffness measurement (LSM). LSM with transient elastography (TE) and acoustic radiation force impulse (ARFI) has been shown to be useful in NAFLD, although the cut-off values have varied among reports. Magnetic resonance elastography and real-time tissue elastography also can be useful for the diagnosis of NAFLD, although the number of studies is limited. Fibrosis is absent in 8-40% of patients with non-alcoholic steatohepatitis (NASH), making it difficult to diagnose NASH by LSM because LSM is usually associated with fibrotic stage. The presence of inflammation or hepatocyte ballooning may affect LSM and aid the diagnosis of NASH without fibrosis. However, obesity significantly increases the failure of LSM and its interference is more conspicuous in TE than in ARFI. The newly implemented XL probe of TE has overcome the difficulty to some degree. Nonetheless, the effects of obesity, hepatocyte ballooning, steatosis and inflammation on LSM values have not yet been adequately investigated, although they are likely to affect LSM values. Further studies are needed to establish the clinical utility of LSM in NAFLD.

Performance of real-time elastography for the staging of hepatic fibrosis: a meta-analysis

Background

With the rapid development of real-time elastography (RTE), a variety of measuring methods have been developed for the assessment of hepatic fibrosis. We evaluated the overall performance of four methods based on RTE by performing meta-analysis of published literature.

Methods

Online journal databases and a manual search from April 2000 to April 2014 were used. Studies from different databases that meet inclusion criteria were enrolled. The statistical analysis was performed using a random-effects model and fixed-effects model for the overall effectiveness of RTE. The area under the receiver operating characteristic curve (AUROC) was calculated for various means. Fagan plot analysis was used to estimate the clinical utility of RTE, and the heterogeneity of the studies was explored with meta-regression analysis.

Results

Thirteen studies from published articles were enrolled and analyzed. The combined AUROC of the liver fibrosis index (LFI) for the evaluation of significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4) were 0.79, 0.94, and 0.85, respectively. The AUROC of the elasticity index (EI) ranged from 0.75 to 0.92 for F≥2 and 0.66 to 0.85 for F = 4. The overall AUROC of the elastic ratio of the liver for the intrahepatic venous vessels were 0.94, 0.93, and 0.96, respectively. The AUROC of the elastic ratio of the liver for the intercostal muscle in diagnosing advanced fibrosis and cirrhosis were 0.96 and 0.92, respectively. There was significant heterogeneity in the diagnostic odds ratio (DOR) for F≥2 of LFI mainly due to etiology (p<0.01).

Conclusion

The elastic ratio of the liver for the intrahepatic vein has excellent precision in differentiating each stage of hepatic fibrosis and is recommend to be applied to the clinic.

Kidney transplant: usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis

The aim of this study is to evaluate the usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis. We prospectively enrolled 50 patients clinically suspected of graft fibrosis. RTE was performed with a broadband linear transducer using a dedicated ultrasound machine. Tissue mean elasticity (TME) was calculated by two blinded operators. All patients underwent biopsy after RTE. To determine cortical fibrosis Banff score was used. The receiver operating characteristic curves analysis was performed to evaluate the accuracy of TME to discriminate between patients with mild fibrosis (F1) versus patients with moderate to severe fibrosis (F2-F3). Inverse correlation between TME values and the degree of fibrosis has been shown (p < 0.05). Patients with F1 had mean TME values significantly higher compared with TME in patients with F2 (p = 0.005) and F3 (p = 0.004). The diagnostic accuracy of TME measurement for F2-F3 evaluated by area under the curve-receiver operating characteristic analysis was 0.95. RTE was able to evaluate kidney fibrosis in a non-invasive way and could be used as complementary imaging during follow-up of renal transplant patients.

Real-time elastography in the assessment of liver fibrosis: a review of qualitative and semi-quantitative methods for elastogram analysis

Despite its invasiveness, liver biopsy is still considered the gold standard for the assessment of hepatic fibrosis. Non-invasive ultrasound-based techniques are increasingly employed to assess parenchymal stiffness and the progression of chronic diffuse liver diseases. Real-time elastography is a rapidly evolving technique that can reveal the elastic properties of tissues. This review examines qualitative and semi-quantitative methods developed for analysis of real-time liver elastograms, to estimate parenchymal stiffness and, indirectly, the stage of fibrosis. Qualitative analysis is the most immediate approach for elastogram analysis, but this method increases intra- and inter-observer variability, which is seen as a major limitation of real-time elastography. Semi-quantitative methods include analysis of the histogram derived from color-coded maps, as well as calculation of the elastic ratio and fibrosis index.

Diagnostic accuracy of real-time tissue elastography for the staging of liver fibrosis: a meta-analysis

OBJECTIVE

To evaluate the overall accuracy of real-time tissue elastography (RTE) for the staging of liver fibrosis.

METHODS

We systematically reviewed 15 studies (1,626 subjects) in which sensitivity and specificity of RTE for liver fibrosis are available. For each cut-off stage of fibrosis, i.e., F ≥ 1, F ≥ 2, F ≥ 3, and F ≥ 4, summary sensitivity and specificity were estimated using a bivariate random-effects model. Publication bias was assessed using funnel plots and Egger's test.

RESULTS

Summary sensitivity and specificity were 0.79 and 0.76 for F ≥ 2, 0.82 and 0.81 for F ≥ 3, and 0.74 and 0.84 for F ≥ 4, respectively. Meta-regressions revealed scoring methods of RTE and liver diseases in the samples might not influence sensitivity and specificity of RTE. However, the estimated accuracy of RTE might be overestimated due to publication bias (p = 0.004 for F ≥ 2, p < 0.001 for F ≥ 3, and p = 0.002 for F ≥ 4).

CONCLUSIONS

RTE is not highly accurate for any cut-off stage of fibrosis. Compared with findings of meta-analyses on Transient Elastography and Acoustic Radiation Force Impulse imaging, the overall accuracy of RTE seems to be nearly identical for the evaluation of significant liver fibrosis, but less accurate for the evaluation of cirrhosis.

KEY POINTS

• Non-invasive methods for evaluating liver fibrosis are necessary to replace liver biopsy. • ARFI is as accurate as TE for evaluating liver fibrosis. • RTE may be as accurate as TE and ARFI for fibrosis. • RTE may be less accurate than TE and ARFI for cirrhosis. • The estimated accuracy of RTE may be overestimated by publication bias.

Radiologic evaluation of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a frequent cause of chronic liver diseases, ranging from simple steatosis to nonalcoholic steatohepatitis (NASH)-related liver cirrhosis. Although liver biopsy is still the gold standard for the diagnosis of NAFLD, especially for the diagnosis of NASH, imaging methods have been increasingly accepted as noninvasive alternatives to liver biopsy. Ultrasonography is a well-established and cost-effective imaging technique for the diagnosis of hepatic steatosis, especially for screening a large population at risk of NAFLD. Ultrasonography has a reasonable accuracy in detecting moderate-to-severe hepatic steatosis although it is less accurate for detecting mild hepatic steatosis, operator-dependent, and rather qualitative. Computed tomography is not appropriate for general population assessment of hepatic steatosis given its inaccuracy in detecting mild hepatic steatosis and potential radiation hazard. However, computed tomography may be effective in specific clinical situations, such as evaluation of donor candidates for hepatic transplantation. Magnetic resonance spectroscopy and magnetic resonance imaging are now regarded as the most accurate practical methods of measuring liver fat in clinical practice, especially for longitudinal follow-up of patients with NAFLD. Ultrasound elastography and magnetic resonance elastography are increasingly used to evaluate the degree of liver fibrosis in patients with NAFLD and to differentiate NASH from simple steatosis. This article will review current imaging methods used to evaluate hepatic steatosis, including the diagnostic accuracy, limitations, and practical applicability of each method. It will also briefly describe the potential role of elastography techniques in the evaluation of patients with NAFLD.

Real-time tissue elastography (RTE) for noninvasive evaluation of fibrosis in liver diseases in children in comparison to liver biopsy

PURPOSE

To determine the value of real-time tissue elastography (RTE) in pediatric liver diseases in comparison to liver biopsy.

METHODS

RTE was performed on 34 patients (♀, n = 17; ♂, n = 17; range 0-21 years) with various acute and chronic liver diseases: autoimmune hepatitis (n = 5), liver transplantation (n = 5), Wilson's disease (n = 4), hepatopathy of unknown origin (n = 4), unclear cholestatic hepatitis (n = 2), thalassemia major (n = 2), glycogenosis (n = 2), hereditary fructose intolerance (n = 1), alpha-1-antitrypsin deficiency (n = 1), diabetes mellitus type 1 (n = 1), chronic intestinal pseudo-obstruction (n = 1), primary sclerosing cholangitis (n = 1), hepatitis B (n = 1), cirrhosis of unknown origin (n = 1), drug-induced hepatopathy (n = 1), unexplained transaminase elevation (n = 1), and nonalcoholic steatohepatitis (n = 1). Included children were biopsied. RTE was performed on a control group (n = 30; ♀, n = 15; ♂, n = 15). The mean value of strain (MEAN) in arbitrary units and the ratio of blue color-coded harder tissue (AREA) were calculated based on an elasticity histogram of the selected region of interest in liver parenchyma. They were compared with the histologically defined grade of liver fibrosis.

RESULTS

In comparison to the scoring systems, a moderate correlation was observed for MEAN and AREA by excluding the F0 patients [MEAN r = -0.575 to -0.645, AREA r = 0.545-0.607 (p < 0.05)]. Differentiation of the control group and low-grade fibrosis (F1) from high-grade fibrosis (F2-4) was significantly possible (p values <0.001 at 5 % significance level).

CONCLUSION

RTE parameters enable a possible differentiation of high fibrosis; however, their correlation with fibrosis stage was moderate. RTE seems to be a promising method in liver fibrosis grading in children.

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.

Non-invasive assessment of liver fibrosis in a rat model: shear wave elasticity imaging versus real-time elastography

The purpose of this study was to investigate the diagnostic value of shear wave elasticity imaging (SWEI) and real-time elastography (RTE) in liver fibrosis induced by dimethylnitrosamine (DMN) and to compare the accuracy of these methods. Seventy male Wistar rats given a single intra-peritoneal injection of DMN and 10 control rats given a saline injection underwent SWEI and RTE to determine their shear wave velocity (V(s)) and liver fibrosis (LF) index, respectively. Correlations between V(s) or the LF index and histologic stage of liver fibrosis (S0-S4) were analyzed, and the diagnostic values of the techniques were assessed using a receiver operating characteristic curve. A positive correlation was found between V(s) and stage of liver fibrosis (r = 0.947, p < 0.001) and between LF index and stage (S) of liver fibrosis (r = 0.662, p < 0.001). For Vs, the areas under the receiver operating characteristic curve for the diagnosis of fibrosis, S ≥ S1, S ≥ S2, S ≥ S3 and S = S4, were 0.983, 0.995, 0.999 and 0.964, respectively; for the LF index, the values were 0.871, 0.887, 0.761 and 0.839, respectively (all p < 0.001). Vs and the LF index values in rats with severe inflammatory activity were significantly higher than those in controls (p < 0.001). In conclusion, positive correlations exist between V(s) or the LF index and the severity of liver fibrosis in rats. Vs is more accurate than the LF index in predicting liver fibrosis in rats. However, severe inflammatory activity may reduce the accuracy of both techniques.

Normal values of liver elasticity measured by real-time tissue elastography (RTE) in healthy infants and children

PURPOSE

To define normal values of liver elasticity measured by real-time tissue elastography (RTE) in healthy infants and children.

METHODS

RTE was performed on 91 children and adolescents by two experienced observers (female, n = 43; male, n = 48) and in two age groups (0-10 years, n = 45; 11-20 years, n = 46). Hepatopathies were excluded clinically by extensive laboratory testing and by ultrasound. RTE provides a histogram from a region of interest (ROI) in the liver representing the degree of stiffness of the liver. The distribution of the colors in the histogram corresponds to organ elasticity. By calculating the mean of stiffness values, a numerical value is expressed in arbitrary units (a.u.) representing the mean elasticity of the liver (MEAN). Additionally, the percentage values of relatively stiffer areas (color coded in blue) in the ROI can be calculated (%AREA). A Mann-Whitney U test was performed for these two parameters according to gender. The reproducibility of these values was determined with an intraclass correlation coefficient (ICC) test on another group of 18 healthy volunteers.

RESULTS

The median elasticity was 106 a.u. Gender did not have an influence on the parameters (MEAN: p = 0.052; %AREA: p = 0.051). Age-specific analyses did not yield any significant difference between the two age groups for either of the two analyzed parameters (MEAN: p = 0.059; %AREA: p = 0.058). The ICC test demonstrated a moderate agreement for MEAN (ICC = 0.582) and %AREA (ICC = 0.659).

CONCLUSION

Real-time elastography is a new sonography-based method and may be used as a supportive analysis to assess liver parenchyma elasticity in children, especially when fibrosis is suspected. We measured RTE normal values in children as reference data.

Liver fibrosis assessment using transient elastography guided with real-time B-mode ultrasound imaging: a feasibility study

Liver fibrosis is a kind of chronic damage of the liver and can lead to cirrhosis, one of the top 10 causes of death in the Western world. However, there is still a lack of noninvasive methods for diagnosing liver fibrosis. Fibroscan (Echosens, Paris, France), a device based on A-mode transient elastography, has shown promising results. In this study, a transient elastography system with real-time B-mode imaging for non-invasive liver fibrosis assessment, named Liverscan, was developed; its performance was tested and compared with that of the Fibroscan. A specific measurement probe was designed and fabricated with a B-mode ultrasound transducer fixed along the axis of a mechanical vibrator. It was integrated with the Liverscan to measure liver stiffness based on the shear wave propagation in liver tissues. The system was validated by mechanical indentation test using custom-made agar-gelatin phantoms with different stiffness. To further test its feasibility, in vivo measurements were conducted in 67 volunteers (age, 34 ± 3 years; body mass index, 21.3 ± 2.8 kg/m(2); Mean ± SD., 34 male and 33 female), including 20 patients with various liver diseases, and 28 (19 male and 9 female) being tested by both Liverscan and Fibroscan. A significant linear correlation between the stiffness measured by the mechanical indentation test and that by the Liverscan (r = 0.973; p < 0.001) was obtained. The in vivo liver stiffness measured by Liverscan was also correlated with that by Fibroscan significantly (r = 0.886; p < 0.001). There was a significant difference in liver stiffness between the 20 patients and the other healthy subjects (14.1 ± 3.4 kPa vs. 10.5 ± 2.1 kPa; p = 0.001). The intra- and inter-observer tests indicated that the measurements were repeatable with intra-class correlation coefficients being 0.987 (p < 0.001) and 0.988 (p < 0.001), respectively. This study demonstrated that Liverscan with a specifically designed probe was able to measure and differentiate liver of different stiffness using the established measurement protocol under the guidance of real-time B-mode ultrasound imaging.

Elastography and Contrast-enhanced Ultrasonography in the Early Detection of Hepatocellular Carcinoma in an Experimental Model of Nonalcoholic Steatohepatitis

BACKGROUND/OBJECTIVE

The early detection of focal hepatic lesions using ultrasound scanning is challenging, and this challenge becomes even greater in the presence of diffuse parenchymal disease. This study aimed to evaluate the diagnostic performance of elastography and contrast-enhanced ultrasonography (CEUS) in the early detection of hepatocellular lesions in an experimental rat model of nonalcoholic steatohepatitis (NASH).

METHODS

B-mode and Doppler ultrasonography was performed weekly in 30 rats divided into a NASH group (n = 20) and a group without liver disease (n = 10). The animals underwent elastography and CEUS and were then euthanized. Liver nodules were assessed by histopathology.

RESULTS

Doppler mapping results of lesions with vascularization were considered indicative of malignancy, with a sensitivity of 29% before and 71% after contrast injection. The specificity was 71% before and 96% after CEUS. Elastograms of positive lesions showed areas of high stiffness, which were indicative of malignancy. This malignancy was confirmed by the histologic evaluation, with a sensitivity of 90% and a specificity of 60%. After CEUS analysis, 4 nodules were identified that were not observed on B-mode ultrasonography. Early wash-in was significantly associated with malignancy (sensitivity of 88% and specificity of 67%).

CONCLUSIONS

Both techniques allow for the correct diagnosis of well-differentiated to moderately differentiated hepatocellular carcinomas with good accuracy in an experimental rat model of NASH.