Performance and cutoffs for liver fibrosis staging of a two-dimensional shear wave elastography technique

Role of multiparametric US in the preoperative assessment of hepatic parenchyma in patients with liver tumors

OBJECTIVES

The aim of this study was to evaluate the diagnostic performance of shear wave elastography (SWE), shear wave dispersion (SWD), and attenuation imaging (ATI) in assessment of hepatic parenchyma in patients with liver tumors before resection.

METHODS

Patients with liver tumors were prospectively enrolled in this study. All participants underwent SWE, SWD, and ATI examinations. Fibrosis stage, necroinflammatory activity and hepatic steatosis grade were determined histopathologically. We evaluated the stability of ATI, SWE and SWD examinations. Multivariable linear regression analyses were conducted to determine the determinant factors for SWE, SWD, attenuation coefficient (AC) values. A receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic performance of multiparametric US (ultrasond).

RESULTS

A total of 280 participants were enrolled in this study. TG (triglyceride) and steatosis for AC value were significant determinant factors. PLT (platelet), PT (prothrombin time), GGT (glutamyl transpeptidase), and fibrosis stage for SWE value were significant determinant factors. PLT, fibrosis stage and inflammation activity for SWD value were significant determinant factors. AC value was correlated with hepatic steatosis. Both SWE and SWD values were correlated with fibrosis stage, inflammation activity, respectively. The area under the ROC (AUROC) curve of ATI for predicting hepatic steatosis grade were 0.910(≥ S1), 0.927(≥ S2), 0.962(= S3), respectively. The AUROC curve of SWE for predicting fibrosis stage were 0.923(≥ S1), 0.934(≥ S2), 0.930(≥ S3), 0.895(= S4), respectively. The AUROC curve of SWD for predicting fibrosis stage were 0.858(≥ S1), 0.886(≥ S2), 0.866(≥ S1) (≥ S3), 0.825(= S4). The AUROC curve of SWE for predicting inflammation activity were 0.846(≥ G1), 0.724(≥ G2), 0.787 (≥ G3), respectively. The AUROC curve of SWD for predicting inflammation activity were 0.777(≥ G1), 0.727(≥ G2), 0.803 (≥ G3), respectively.

CONCLUSIONS

For patients with liver tumors, ATI technology showed excellent feasibility and diagnostic performance for detecting and grading hepatic steatosis, SWE was more accurate in detecting fibrosis stage than SWD, SWD was not superior to SWE in detecting inflammation activity.

Diagnostic Performance of Quantitative Ultrasound Parameters in Non-alcoholic Fatty Liver Disease

RATIONALE AND OBJECTIVES

Marked liver steatosis, steatohepatitis, and significant fibrosis are risk factors for unfavorable outcomes in non-alcoholic fatty liver disease (NAFLD). In this study, the diagnostic performance of attenuation coefficient (AC), liver stiffness (LS), and dispersion slope (DS) was evaluated separately and combined in the diagnosis of liver steatosis and fibrosis in NAFLD suspects using biopsy or magnetic resonance imaging (MRI) as a reference standard.

MATERIALS AND METHODS

Seventy-four NAFLD suspects were prospectively imaged with an Aplio i800 ultrasound scanner (Canon Medical Systems, Tustin, CA). AC, LS, and DS measurements were obtained from the right liver lobe.

RESULTS

Thirty-four patients underwent liver biopsy, and 40 had MRI. There were 32 patients (43%) with liver steatosis and fibrosis (S + F), 22 (30%) with steatosis (S), 5 (7%) with fibrosis (F), and 15 (20%) with normal liver (N). Mean ACs were significantly higher in steatotic livers (n = 54) than in non-steatotic livers (n = 20) (P < 0.0001). LS and DS were significantly higher in patients with liver fibrosis (n = 37) compared to non-fibrotic livers (n = 37) (P = 0.0004 and P = 0.0002, respectively). In detecting (S + F), the area under the receiver operating characteristic curve (AUROCC) was 0.87 for combined ultrasound parameters of LS and AC (negative predictive value [NPV]: 75%, positive predictive value [PPV]: 77%, P < 0.0001). In detecting patients with liver steatosis and fibrosis stage ≥2, LS had an AUROCC of 0.93 (NPV: 87%, PPV: 82%, P < 0.0001). In the biopsy group, 32% (11/34) were diagnosed with non-alcoholic steatohepatitis (NASH). DS values showed a significant difference among patients with (n = 23) or without (n = 11) hepatocellular ballooning (P = 0.02). AUROCC was 0.87 for combined ultrasound parameters of AC, LS, and DS with body mass index (BMI) in detecting NASH (NPV: 80%, PPV: 87%, P = 0.0006).

CONCLUSION

AC and LS showed high diagnostic value in detecting liver steatosis and fibrosis, respectively. The combined AC and LS values further improved the diagnostic accuracy in detecting NAFLD and high-risk NAFLD patients.

Corrected and republished from: Metabolic associated liver disease

Alcohol consumption (AC) and metabolic syndrome (MS) represent the first cause of liver disease, hepatocellular carcinoma and liver transplantation. The habit of consuming alcoholic beverages and the presence of MS and non-alcoholic fatty liver disease (NAFLD) often coexist in the same patient. The histoclinical boundaries between alcohol related liver disease (ALD) and NAFLD are often not well defined. The co-presence of AC and MS increases the risk of hepatic and extra-hepatic disease. The terminological evolution from NAFLD to metabolic associated fatty liver disease (MAFLD) is certainly a useful advance. However, it is known that the appearance of liver fibrosis increases oncologic and cardiovascular disease risk, which in the case of cirrhosis can be present even in the absence of steatosis and that the mechanisms of fibrogenesis can act independently of the presence of steatosis/steatohepatitis. For this reason, as already stated recently, a further terminological evolution can be hypothesized. This article was originally published with mistakes in the text. The new corrected citable version appears below.

Influence of Measurement Depth and Acquisition Parameters on Shear Wave Speed and Shear Wave Dispersion in Certified Phantoms Using a Canon Aplio Clinical Ultrasound Scanner

OBJECTIVE

The aim of the work described here was to investigate the relative contribution of confounding factors on liver shear wave speed (SWS) and shear wave dispersion slope (SWDS) measurements in three certified phantoms using a Canon Aplio clinical ultrasound scanner.

METHODS

A Canon Aplio i800 i-series ultrasound system (Canon Medical Systems Corporation, Otawara, Tochigi, Japan) with i8CX1 convex array (center frequency = 4 MHz) was used to examine dependencies caused by the depth, width and height of the acquisition box (AQB), the depth and size of the region of interest (ROI), the AQB angle and the pressure of the ultrasound probe on the surface of the phantom.

RESULTS

Results revealed that depth is the most significant confounder in both SWS and SWDS measurements. AQB angle, height and width and ROI size exhibited minimal confounding effects on measurements. For SWS, the most consistent measurement depth is when the top of the AQB is placed between 2 and 4 cm, and the ROI is located between 3 and 7 cm deep. For SWDS, results indicate that measurement values significantly decrease with depth from the surface of the phantom until approximately 7 cm deep, and consequently no stable area of AQB placement or ROI depth exists.

CONCLUSION

In contrast to SWS, the same ideal acquisition depth range cannot necessarily be applied to SWDS measurements because of a significant depth dependency.

Risk Factors for Hepatitis E Virus Infection and Eating Habits in Kidney Transplant Recipients

There is a significant risk for ongoing and treatment-resistant courses of hepatitis E virus (HEV) infection in patients after solid organ transplantation. The aim of this study was to identify risk factors for the development of hepatitis E, including the dietary habits of patients. We conducted a retrospective single-center study with 59 adult kidney and combined kidney transplant recipients who were diagnosed with HEV infection between 2013 and 2020. The outcomes of HEV infections were analyzed during a median follow-up of 4.3 years. Patients were compared with a control cohort of 251 transplant patients with elevated liver enzymes but without evidence of an HEV infection. Patients' alimentary exposures during the time before disease onset or diagnosis were assessed. Previous intense immunosuppression, especially treatment with high-dose steroids and rituximab, was a significant risk factor to acquire hepatitis E after solid organ transplantation. Only 11 out of 59 (18.6%) patients reached remission without further ribavirin (RBV) treatment. A total of 48 patients were treated with RBV, of which 19 patients (39.6%) had either viral rebounds after the end of treatment or did not reach viral clearance at all. Higher age (>60 years) and a BMI ≤ 20 kg/m² were risk factors for RBV treatment failure. Deterioration in kidney function with a drop in eGFR (p = 0.046) and a rise in proteinuria was more common in patients with persistent hepatitis E viremia. HEV infection was associated with the consumption of undercooked pork or pork products prior to infection. Patients also reported processing raw meat with bare hands at home more frequently than the controls. Overall, we showed that the intensity of immunosuppression, higher age, a low BMI and the consumption of undercooked pork meat correlated with the development of hepatitis E.

Shear Wave Dispersion in Chronic Liver Disease: From Physical Principles to Clinical Usefulness

The development of new applications in ultrasound (US) imaging in recent years has strengthened the role of this imaging technique in the management of different pathologies, particularly in the setting of liver disease. Improved B-mode imaging (3D and 4D), contrast-enhanced US (CEUS) and especially US-based elastography techniques have created the concept of multiparametric ultrasound (MP-US), a term borrowed from radiological sectional imaging. Among the new elastography techniques, shear wave dispersion is a newly developed imaging technology which enables the assessment of the shear waves' dispersion slope. The analysis of the dispersion qualities of shear waves might be indirectly related to the tissue viscosity, thus providing biomechanical information concerning the pathologic state of the liver such as necroinflammation. Some of the most recent US devices have been embedded with software that evaluate the dispersion of shear waves/liver viscosity. In this review, the feasibility and the clinical applications of liver viscosity are reviewed based on the preliminary findings of both animal and human studies.

Clinical Application of Shear Wave Elastography With Shear Wave Dispersion Imaging in the Preoperative Evaluation of Hepatic Parenchyma in Patients With Liver Tumors

OBJECTIVES

This study aimed to compare the diagnostic accuracy of shear wave elastography (SWE) with that of shear wave dispersion (SWD) in evaluation of hepatic parenchyma in patients with liver tumors before resection.

METHODS

A total of 174 patients with liver tumors were prospectively enrolled. SWE and SWD examinations were performed. Fibrosis stage and necroinflammatory activity were determined histopathologically according to the Scheuer standard. We compared the diagnostic accuracy of SWE and SWD.

RESULTS

Both SWE and SWD values of the liver were highly correlated with liver fibrosis stage (P < .05, respectively). Both SWE and SWD values of the liver were moderately correlated with necroinflammatory activity (P < .05, respectively). Both SWE and SWD values of the liver were not correlated with steatosis (P > .05, respectively). Both SWE and SWD values were significantly different among the patients with different stages of liver fibrosis (P < .001, respectively). The area under the receiver operating characteristic (ROC) curve of SWE value was 0.982, 0.977, 0.969, and 0.984 for predicting S ≥ 1, S ≥ 2, S ≥ 3, and S = 4, respectively. The optimal cutoff SWE values were 6.9, 7.9, 8.7, and 10.6 kPa for S ≥ 1, S ≥ 2, S ≥ 3, and S = 4, respectively. The area under the ROC curve of SWD value was 0.967, 0.960, 0.925, and 0.954 for predicting S ≥ 1, S ≥ 2, S ≥ 3, and S = 4, respectively. The optimal cutoff SWD values were 11.2, 12.0, 13.2, and 16.0 m/s/kHz for S ≥ 1, S ≥ 2, S ≥ 3, and S = 4, respectively.

CONCLUSIONS

SWE and SWD could be noninvasive and accurate for predicting the stage of liver fibrosis in patients with liver tumors before surgery. SWE was more accurate than SWD in predicting severe fibrosis (S ≥ 3) and cirrhosis (S = 4).

Performance of two-dimensional shear wave elastography and transient elastography compared to liver biopsy for staging of liver fibrosis

BACKGROUND

Staging of liver fibrosis traditionally relied on liver histology; however, transient elastography (TE) and more recently two-dimensional shear wave elastography (2D-SWE) evolved to noninvasive alternatives. Hence, we evaluated the diagnostic accuracy of 2D-SWE assessed by the Canon Aplio i800 ultrasound system using liver biopsy as reference and compared the performance to TE.

METHODS

In total, 108 adult patients with chronic liver disease undergoing liver biopsy, 2D-SWE and TE were enrolled prospectively at the University Hospital Zurich. Diagnostic accuracies were evaluated using the area under the receiver operating characteristic (AUROC) analysis, and optimal cut-off values by Youden's index.

RESULTS

Diagnostic accuracy of 2D-SWE was good for significant (≥F2; AUROC 85.2%, 95% confidence interval (95%CI):76.2-91.2%) as well as severe fibrosis (≥F3; AUROC 86.8%, 95%CI: 78.1-92.4%) and excellent for cirrhosis (AUROC 95.6%, 95%CI: 89.9-98.1%), compared to histology. TE performed equally well (significant fibrosis: 87.5%, 95%CI: 77.7-93.3%; severe fibrosis: 89.7%, 95%CI: 82.0-94.3%; cirrhosis: 96%, 95%CI: 90.4-98.4%), and accuracy was not statistically different to 2D-SWE. 2D-SWE optimal cut-off values were 6.5, 9.8 and 13.1 kPa for significant fibrosis, severe fibrosis and cirrhosis, respectively.

CONCLUSIONS

Performance of 2D-SWE was good to excellent and well comparable with TE, supporting the application of this 2D-SWE system in the diagnostic workup of chronic liver disease.

Impact of Breathing Phase, Liver Segment, and Prandial State on Ultrasound Shear Wave Speed, Shear Wave Dispersion, and Attenuation Imaging of the Liver in Healthy Volunteers

OBJECTIVES

Measurement location and patient state can impact noninvasive liver assessment and change clinical staging in ultrasound examinations. Research into differences exists for Shear Wave Speed (SWS) and Attenuation Imaging (ATI), but not for Shear Wave Dispersion (SWD). The aim of this study is to assess the effect of breathing phase, liver lobe, and prandial state on SWS, SWD, and ATI ultrasound measurements.

METHODS

Two experienced examiners performed SWS, SWD, and ATI measurements in 20 healthy volunteers using a Canon Aplio i800 system. Measurements were taken in the recommended condition (right lobe, following expiration, fasting state), as well as (a) following inspiration, (b) in the left lobe, and (c) in a nonfasting state.

RESULTS

SWS and SWD measurements were strongly correlated (r = 0.805, p < 0.001). Mean SWS was 1.34 ± 0.13 m/s in the recommended measurement position and did not change significantly under any condition. Mean SWD was 10.81 ± 2.05 m/s/kHz in the standard condition and significantly increased to 12.18 ± 1.41 m/s/kHz in the left lobe. Individual SWD measurements in the left lobe also had the highest average coefficient of variation (19.68%). No significant differences were found for ATI.

CONCLUSION

Breathing and prandial state did not significantly affect SWS, SWD, and ATI values. SWS and SWD measurements were strongly correlated. SWD measurements in the left lobe showed a higher individual measurement variability. Interobserver agreement was moderate to good.

Hepatic steatosis: Ultrasound assessment using attenuation imaging (ATI) with liver biopsy correlation

INTRODUCTION

Hepatic steatosis duration and severity are risk factors for liver fibrosis and cardiometabolic disease. We assessed the diagnostic accuracy of attenuation imaging (ATI), compared with histologic hepatosteatosis grading in adults with varied suspected liver pathologies.

METHODS

Liver biopsy was performed on 76 patients (51 women, 25 men) with non-malignant diffuse parenchymal liver disease, within 4 weeks of multiparametric liver ultrasound including attenuation imaging (ATI). Skin-liver capsule distance (SCD) and body mass index (BMI) were measured. Histologic steatosis was graded none (S0), mild (S1), moderate (S2) or severe (S3). We compared histology and sonographic parameters.

RESULTS

The median patient age was 50.5 (range 18-83) years and BMI 28.9 kg/m² (interquartile range 24.0-33.3). The distribution of histologic steatosis grade was S0 (44%), S1(17%), S2(30%) and S3(9%). Median ATI value for each biopsy steatosis grade was 0.60 (IQR: 0.52-0.65), 0.65 (IQR: 0.6-0.71), 0.83 (IQR: 0.74-0.90) and 0.90 (IQR: 0.82-1.01) dB/cm/MHz for S0, S1, S2 and S3, respectively. The AUC of ATI for detection of any steatosis (S1-S3) and moderate to severe steatosis (S2-S3) was 0.85 (95% CI: 0.75-0.91) and 0.91 (95% CI: 0.83-0.99) with cut-offs of 0.55 and 0.62 dB/cm/MHz. ATI threshold of 0.74 dB/cm/MHz was able to discriminate between S0-S1 and S2-3 with accuracy, CI and kappa statistic of 0.8889, 0.65-0.98 and 0.7534.

CONCLUSION

We found a good correlation between ATI and steatosis grade. The most accurate discrimination was between none to mild (S0-1) and moderate to severe (S2-3) steatosis.

Clinical application of two dimensional shear wave elastography with a propagation map in evaluating liver fibrosis in patients with liver tumors

OBJECTIVE

This study aimed to evaluate the diagnostic performance of two-dimensional shear wave elastography (2D-SWE) with a propagation map in evaluating the degree of hepatic fibrosis in patients with liver tumors before resection.

METHODS AND MATERIALS

From January 2020 to April 2021, 128 patients with liver tumors were prospectively enrolled, including 20 benign liver tumors and 108 malignant liver tumors. 2D-SWE with a propagation map technology was used to measure the stiffness of liver parenchyma 2 cm away from the tumor. The median value of five measurements was used in this study. The stage of hepatic fibrosis was graded in accordance with Scheuer standard. Spearman correlation was used to analyze the correlation between liver fibrosis stage and the liver stiffness. Univariate and multivariate linear regression analyses were used to determine significant affecting factors for liver stiffness value. The diagnostic performance of 2D-SWE with a propagation map in predicting fibrosis stage was evaluated by receiver operating characteristic curve analysis.

RESULTS

The median liver stiffness value in patients with benign liver tumors was lower than that in patients with malignant liver tumors (6.0 kPa vs. 9.4 kPa, p < 0.05). The median liver stiffness values in patients with primary liver cancer were higher than that in patients with benign liver tumors and other types of malignant liver tumors (9.6 kPa vs. 6.0 kPa, p < 0.05). The liver stiffness measured by 2D-SWE was highly correlated with the fibrosis stage confirmed by postoperative pathology (r = 0.834, p < 0.05). For the liver stiffness value, PLT,TB,ALB and fibrosis stage are significantly associated with liver stiffness. The median liver stiffness values in stages S0-S4 of fibrosis were 6.0, 7.2, 8.0, 9.4, and 12.6 kPa, respectively. The areas under the ROC curve of S≥1, S≥2, S≥3, and S = 4 as predicted by SWE were 0.932, 0.945, 0.945, and 0.916, respectively. According to the Youden index, the optimal critical values for predicting fibrosis S≥1, S≥2, S≥3, and S = 4 were 6.8 (sensitivity of 89.69% and specificity of 93.55%), 7.5 (sensitivity of 87.50 % and specificity of 95.00 %), 8.3 (sensitivity of 87.14 % and specificity of 87.93 %) and 9.8 (sensitivity of 79.55 % and specificity of 86.90 %) kPa.

CONCLUSION

2D-SWE with a propagation map could noninvasively and accurately predict the staging of liver fibrosis in patients with liver tumors before resection.

Clinical application of preoperative shear wave dispersion for prediction of post liver failure in patients with hepatocellular carcinoma after hepatectomy

OBJECTIVE

The aim in this study was to determine the efficacy of shear wave dispersion (SWD) technique for the prediction of post hepatectomy liver failure (PHLF) in patients with hepatocellular carcinoma after hepatectomy and develop an SWD based risk prediction model.

METHODS & MATERIALS

We prospectively enrolled 205 consecutive patients who were scheduled to undergo hepatectomy for hepatocellular carcinoma (HCC), pre-operative SWD examination, laboratory data and some other clinicopathological tests were collected. The risk factors of PHLF were identified according to univariate and multivariate analysis, a predictive model was established based on logistic regression analyses.

RESULTS

SWD examination was successfully performed in 205 patients. PHLF occurred in 51 patients (24.9%), including 37/11/3 patients with Grade A/B/C, respectively. There was a high correlation between SWD value of liver and liver fibrosis stage (r = 0.873, p < 0.05). Patients with PHLF has a higher median SWD value of liver than patients without PHLF [17.4 vs 14.7 (m/s)/kHz, p < 0.05]. The SWD value of liver, total bilirubin (TB), international normalized ratio of prothrombin time (INR) and splenomegaly were significantly related to PHLF based on the multivariate analysis. A new prediction model (PM) for PHLF was established (PM = -12.918 + 0.183× SWD + 6.668× INR +0.100×TB+1.240×splenomegaly). The optimal cutoff value of SWD for predicting PHLF was 16.7 (m/s)/kHz. The area under the curve (AUC) of the PM for PHLF was 0.833, which was higher than that of SWD, INR, Forns, FIB4, APRI (p < 0.005, respectively).

CONCLUSION

SWD is a promising and reliable method for PHLF prediction in patients with HCC who were undergoing hepatectomy. Compared with SWD, Forns, APRI and FIB-4, PM demonstrate better efficacy for preoperative PHLF prediction.

Validation of attenuation imaging coefficient, shear wave elastography, and dispersion as emerging tools for non-invasive evaluation of liver tissue in children

Introduction

The number of children with acute and chronic liver disease is rising. Moreover, liver involvement may be limited to subtle changes in organ texture especially in early childhood and some syndromic conditions, such as ciliopathies. Attenuation imaging coefficient (ATI), shear wave elastography (SWE), and dispersion (SWD) are emerging ultrasound technologies providing data about attenuation, elasticity, and viscosity of liver tissue. This additional and qualitative information has been correlated with certain liver pathologies. However, limited data are available for healthy controls and have mainly been raised in adults.

Methods

This prospective monocentric study was conducted at a university hospital with a specialization in pediatric liver disease and transplantation. Between February and July 2021, 129 children aged 0-17.92 years were recruited. Study participants attended outpatient clinics due to minor illnesses excluding liver or cardiac diseases, acute (febrile) infections or other conditions affecting liver tissue and function. ATI, SWE, and SWD measurements were performed on an Aplio i800 (Canon Medical Systems) with an i8CX1 curved transducer by two different investigators with long-standing experience in pediatric ultrasound according to a standardized protocol.

Results

Considering multiple potential covariates, we derived percentile charts for all 3 devices relying on the Lambda-Mu-Sigma (LMS) approach. 112 children were considered for further analysis, excluding those with abnormal liver function and under-/overweight (BMI SDS<-1.96/> 1.96, respectively). Age range was 0-17.92 years (mean 6.89±0.50SD), 58% were male. The mean duration of the ultrasound examination (basic ultrasound plus SWE, SWD, and ATI) was 6.67±0.22 minutes and it was well tolerated in 83% (n=92) of cases. While ATI was related to age, SWD was found to depend on BMI SDS, and SWE on abdominal wall thickness and sex. ATI correlated with neither SWE nor SWD, but SWE was correlated with SWD.

Conclusions

Our study provides norm values and reference charts for ATI, SWE, and SWD considering important covariates including age, sex and, BMI. This may help to implement these promising tools into imaging diagnostics of liver disease and to improve the diagnostic relevance of liver ultrasound. In addition, these noninvasive techniques proved to be time-effective and highly reliable, which make them ideal for application in children.

Metabolic associated liver disease

In real practice the patient with liver disease is often the carrier of multiple etiological factors such as metabolic syndrome (MS) and alcohol consumption (AC). Their copresence is often underestimated and AC is not adequately studied. Traditionally to diagnose non-alcoholic fatty liver disease (NAFLD), AC must not exceed 30 gr for men and 20 gr for women per day. This limit should still be reduced, especially in relation to the AC and fibrogenesis ratio and also frequent misestimation of AC or unrecognized MS may underestimate multi caused liver injury. AC is a contributing cause of MS and alcoholic and non-alcoholic liver disease have a substantially overlapping histopathological picture. Moreover, AC and MS are cause and contributing cause of extra-hepatic morbidity and mortality. It can be concluded that the possible simplification of terminology at metabolic associated liver disease (MALD) makes clinical activity more usable and immediate, facilitates better communication and cooperation between scientific societies and specialists who apparently deal with different medical sectors, facilitates early identification of related hepatic and extra-hepatic pathology, allows to "see the person in a unitary way," to create more streamlined care pathways, to reduce the hospitalization rate with relative cost-benefit advantage and to create unitary prevention and health promotion policies.

Reduction of Shear Wave Elastography but Not Shear Wave Dispersion After Successful Hepatitis C Treatment With Direct-Acting Antiviral Agents

OBJECTIVES

Successful antiviral treatment in patients with hepatitis C can lead to reduced liver stiffness. In this study, we attempted to compare 2-dimensional (2D) shear wave elastography (SWE), shear wave dispersion (SWD), and attenuation imaging (ATI) with transient elastography (TE) and the controlled attenuation parameter (CAP) in patients under direct-acting antiviral (DAA) therapy.

METHODS

Patients with chronic hepatitis C infection undergoing DAA therapy from January 2017 to June 2020 were retrospectively examined. The results of 2D SWE, SWD, ATI, TE, and CAP were recorded before and 12 weeks after the completion of DAA therapy.

RESULTS

A total of 122 patients with a median age of 61 years were investigated; among them, 121 (99.2%) achieved a sustained virologic response at 12 weeks after DAA therapy. Fibrosis 4, the aspartate aminotransferase-to-platelet ratio index, 2D SWE, and TE were reduced after DAA therapy. The CAP was increased; however, SWD and ATI showed no statistically significant changes after DAA therapy. Two-dimensional SWE and TE were strongly correlated (r = 0.885-0.897; P < .001). Albumin and the baseline liver stiffness measurement were independent factors of liver stiffness measurement changes after DAA therapy.

CONCLUSIONS

Direct-acting antiviral therapy can significantly decrease liver stiffness (using both 2D SWE and TE) but not SWD and ATI values in patients with hepatitis C. An increased CAP is also observed after DAA therapy.

Diagnostic Performance of 2-D Shear-Wave Elastography with Propagation Maps and Attenuation Imaging in Patients with Non-Alcoholic Fatty Liver Disease

We aimed to investigate the diagnostic performance of new 2-D shear-wave elastography (SWE) with propagation maps and attenuation imaging (ATI) for quantification of fibrosis and steatosis in non-alcoholic fatty liver disease (NAFLD). Consecutive patients with NAFLD and healthy volunteers underwent liver stiffness measurement and steatosis quantification by means of vibration-controlled transient elastography coupled with the controlled attenuation parameter as the reference and by 2-D shear-wave elastography (2-D-SWE) with propagation maps and ATI as the investigational methods. We included 232 participants (164 in the NAFLD group and 68 in the healthy control group): 51.7%/49.3% women/men; mean age, 54.2 ± 15.2 y; mean body mass index, 29.4 ± 6.5 kg/m². Significant correlations were found between 2-D-SWE and vibration-controlled transient elastography (r = 0.71, p < 0.0001) and between ATI and the controlled attenuation parameter (r = 0.72, p < 0.0001). NAFLD-specific 2-D-SWE liver stiffness measurement cutoffs were as follows-F ≥ 2: 7.9 kPa (area under the curve [AUC] = 0.91); F ≥ 3: 10 kPa (AUC = 0.92); and F = 4: 11.4 kPa (AUC = 0.95). For steatosis, the best cutoffs by ATI were as follows-S1 = 0.73 dB/cm/MHz (AUC = 0.86); S2 = 0.76 dB/cm/MHz (AUC = 0.86); and S3 = 0.80 dB/cm/MHz (AUC = 0.83). According to Baveno VI criteria, the optimal 2-D-SWE liver stiffness measurement for diagnosing liver cirrhosis is 15.5 kPa (AUC = 0.94), and for ruling out compensated advanced chronic liver disease it is 9.2 kPa (AUC = 0.92). To conclude, 2-D-SWE with propagation maps and ATI is reliable for quantification of liver fibrosis and steatosis in patients with NAFLD.

Attenuation Imaging with Ultrasound as a Novel Evaluation Method for Liver Steatosis

In recent years, ultrasound attenuation imaging (ATI) has emerged as a new method to detect liver steatosis. However, thus far, no studies have confirmed the clinical utility of this technology. Using a retrospective database analysis of 28 patients with chronic liver disease who underwent ultrasound liver biopsy and ATI, we compared the presence and degree of steatosis measured by ATI with the results obtained through liver biopsy. The area under the receiver operating characteristic curve (AUROC) of the ATI for differentiating between normal and hepatic steatosis was 0.97 (95% confidence interval: 0.83–1.00). The AUROC of the ATI was 0.99 (95% confidence interval: 0.86–1.00) in grade ≥2 liver steatosis and 0.97 (95% confidence interval: 0.82–1.00) in grade 3. ATI showed good consistency and accuracy for the steatosis grading of liver biopsy. Therefore, ATI represents a novel diagnostic measurement to support the diagnosis of liver steatosis in non-invasive clinical practice.

What does liver elastography measure? Technical aspects and methodology

Elastography can be thought as an extension of the ancient technique of palpation. After giving a short introduction to the history of elastography, the different technologies that are nowadays available and the physics behind them, the article focuses on the assessment of liver stiffness in patients with diffuse liver disease using shear wave elastography (SWE). Practical advices on how to perform the SWE techniques and on the factors that should be considered for a correct interpretation of the results are given. This paper aimed to provide a practical guide for beginners and advanced clinical users to better understand technical aspects, methodologies and terminology.