Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement

Quantification of Liver Fat Content with the iATT Algorithm: Correlation with Controlled Attenuation Parameter

Background: The primary aim of our study was to assess the correlation between an improved version of the attenuation coefficient available on the Arietta 850 ultrasound system (iATT, Fujifilm Healthcare, Tokyo, Japan) and controlled attenuation parameter (CAP). The secondary aim was to assess whether focusing only on iATT acquisition without following the strict protocol for liver stiffness measurements would affect iATT measurement. Methods: Consecutive individuals were enrolled. Pearson’s r was used to test the correlation between ATT and CAP values. The concordance between iATT and CAP was tested using Lin’s concordance correlation coefficient (CCC). Results: 354 individuals (203 males, 151 females) were studied. The overall Pearson correlation between CAP and iATT values obtained following or not following the liver stiffness measurement protocol, respectively, were r = 0.73 and r = 0.71. The correlation was affected by the interquartile range/median (IQR/M) of the 10 measurements: it was r = 0.75 for IQR/M ≤ 15% and r = 0.60 for IQR/M > 15%. CCC showed that there was a moderate to good concordance between iATT and CAP values. Conclusion: iATT shows a strong correlation with CAP that does not decrease when the protocol for liver stiffness acquisition is not followed. The correlation between iATT and CAP values is higher when the IQR/M ≤ 15%.

Steatosis Grading Comparison Between Qualitative Ultrasonography and Magnetic Resonance Spectroscopy in Patients With Nonalcoholic Fatty Liver Disease

Objective:

Assess the correlation between the qualitative sonographic score for detecting hepatic steatosis (HS) and liver fat quantification, using proton magnetic resonance spectroscopy (MRS).

Materials and Methods:

Sixty-six patients with known or suspected nonalcoholic fatty liver disease (NAFLD) underwent ultrasonography (US) and magnetic resonance imaging (MRI). The qualitative sonographic score and fat quantification, measured by MRS, were the techniques used. A Kappa coefficient was used for agreement calculation, and a Fisher test was used to assess the normality of the variables. The MRS results were the gold standard for US quality assessment.

Results:

The agreement between MRS and US was 50% (Kappa 0.35). Ultrasonography results were more severe in 42.4% of the cases, and 66.7% of the patients had a body mass index greater than 30 ( P = .017). For diagnosis of HS, US presented 100% sensitivity, 30.8% to 60% specificity, 61.7% to 72.7% accuracy, 40% to 69.2% false-positive rate, 0% false-negative rate, 53.8% positive predictive value, and 100% negative predictive value.

Conclusion:

Ultrasonography is a reliable exam for detecting HS, although not for grading purposes. Therefore, US is not a good predictor of HS severity for the management and follow-up of NAFLD.

Diagnostic Performance of Attenuation to Stage Liver Steatosis with MRI Proton Density Fat Fraction as Reference: A Prospective Comparison of Three US Machines

Background US tools to quantify liver fat content have recently been made clinically available by different vendors, but comparative data on their accuracy are lacking. Purpose To compare the diagnostic performances of the attenuation parameters of US machines from three different manufacturers (vendors 1, 2, and 3) in participants who underwent liver fat quantification with the MRI-derived proton density fat fraction (PDFF). Materials and Methods From July 2020 to June 2021, consecutive participants with chronic liver disease were enrolled in this prospective single-center study and underwent MRI PDFF quantification (reference standard) and US on the same day. US was performed with two different machines from among three vendors assessed. Areas under the receiver operating characteristic curve (AUCs) for the staging of liver steatosis (MRI PDFF: ≥5.5% for grade ≥S1 and ≥15.5% for grade ≥S2) were calculated in test and validation samples and then compared between vendors in the study sample. Results A total of 534 participants (mean age, 60 years ± 13 [SD]; 320 men) were evaluated. Failure of measurements occurred in less than 1% of participants for all vendors. Correlation coefficients with the MRI PDFF were 0.71, 0.73, and 0.54 for the attenuation coefficients of vendors 1, 2, and 3, respectively. In the test sample, AUCs for diagnosis of steatosis grade S1 and higher and grade S2 and higher were 0.89 and 0.93 for vendor 1 attenuation, 0.88 and 0.92 for vendor 2 attenuation, and 0.79 and 0.79 for vendor 3 attenuation, respectively. In the validation sample, a threshold value of 0.65 for vendor 1 and 0.66 for vendor 2 yielded sensitivity of 77% and 84% and specificity of 78% and 85%, respectively, for diagnosis of grade S1 and higher. Vendor 2 attenuation had greater AUCs than vendor 3 attenuation (P = .001 and P = .003) for diagnosis of grade S1 and higher and grade S2 and higher, respectively, and vender 2 had greater AUCs for attenuation than vendor 1 for diagnosis of grade S2 and higher (P = .04). For all vendors, attenuation was not associated with liver stiffness (correlation coefficients <0.05). Conclusion To stage liver steatosis, attenuation coefficient accuracy varied among US devices across vendors when using MRI proton density fat fraction quantification as the reference standard, with some demonstrating excellent diagnostic performance and similar cutoff values. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Dubinsky in this issue.

Three-Dimensional Shear Wave Elastography Using a 2D Row Column Addressing (RCA) Array

Objective. To develop a 3D shear wave elastography (SWE) technique using a 2D row column addressing (RCA) array, with either external vibration or acoustic radiation force (ARF) as the shear wave source. Impact Statement. The proposed method paves the way for clinical translation of 3D SWE based on the 2D RCA, providing a low-cost and high volume rate solution that is compatible with existing clinical systems. Introduction. SWE is an established ultrasound imaging modality that provides a direct and quantitative assessment of tissue stiffness, which is significant for a wide range of clinical applications including cancer and liver fibrosis. SWE requires high frame rate imaging for robust shear wave tracking. Due to the technical challenges associated with high volume rate imaging in 3D, current SWE techniques are typically confined to 2D. Advancing SWE from 2D to 3D is significant because of the heterogeneous nature of tissue, which demands 3D imaging for accurate and comprehensive evaluation. Methods. A 3D SWE method using a RCA array was developed with a volume rate up to 2000 Hz. The performance of the proposed method was systematically evaluated on tissue-mimicking elasticity phantoms and in an in vivo case study. Results. 3D shear wave motion induced by either external vibration or ARF was successfully detected with the proposed method. Robust 3D shear wave speed maps were reconstructed for phantoms and in vivo. Conclusion. The high volume rate 3D imaging provided by the 2D RCA array provides a robust and practical solution for 3D SWE with a clear pathway for future clinical translation.

Combined Liver Stiffness and Α-fetoprotein Further beyond the Sustained Virologic Response Visit as Predictors of Long-Term Liver-Related Events in Patients with Chronic Hepatitis C

AIMS

Long-term risk stratification using combined liver stiffness (LS) and clinically relevant blood tests acquired at the baseline further beyond the sustained virologic response (SVR) visit for chronic hepatitis C (CHC) has not been thoroughly investigated. This study retrospectively investigated the prognostics of liver-related events (LREs) further beyond the SVR visit.

METHODS

Cox regression and random forest models identified the key factors, including longitudinal LS and noninvasive test results, that could predict LREs, including hepatocellular carcinoma, during prespecified follow-ups from 2010 to 2021. Kaplan-Meier survival analysis estimated the significance of between-group risk stratification.

RESULTS

Of the entire eligible cohort (n = 520) of CHC patients with SVR to antiviral therapy, 28 (5.4%) patients developed post-SVR LREs over a median follow-up period of 6.1 years (interquartile range = 3.5-8.7). The multivariate Cox regression analysis identified two significant predictors of LREs after the year 3 post-SVR (Y3PSVR) baseline (LRE, n = 15 of 28, 53.6%, median follow-up = 4.1 [1.6-6.4] years after Y3PSVR): LS at Y3PSVR (adjusted hazard ratio [aHR] = 3.980, 95% confidence interval [CI] = 2.085-7.597, P < 0.001), and α-fetoprotein (AFP) at Y3PSVR (aHR = 1.017, 95% CI = 1.001-1.034, P=0.034). LS ≥1.45 m/s and AFP ≥3.00 ng/mL for Y3PSVR yielded positive likelihood ratios of 4.24 and 2.62, respectively. Kaplan-Meier analysis revealed that among the stratified subgroups, the subgroup with concurrent LS ≥1.45 m/s and AFP ≥3.00 ng/mL at Y3PSVR exhibited the highest risk of LREs after Y3PSVR (log-rank P < 0.001).

CONCLUSION

We recommend the combined use of concurrent LS and AFP in future prediction models for LREs in CHC. Patients with concurrently high LS and AFP values further beyond the SVR visit may require a recall policy involving intense surveillance.

Ultrasound Shear Wave Elastography, Shear Wave Dispersion and Attenuation Imaging of Pediatric Liver Disease with Histological Correlation

Aim: To evaluate the feasibility of multiple ultrasound markers for the non-invasive characterization of fibrosis, inflammation and steatosis in the liver in pediatric patients. Materials and methods: The quantitative ultrasound measures shear wave elastography (SWE), shear wave dispersion (SWD) and attenuation imaging (ATI) were compared and correlated with percutaneous liver biopsies and corresponding measures in a control cohort. Results: The median age of the 32 patients was 12.1 years (range 0.1−17.9), and that of the 15 controls was 11.8 years (range: 2.6−16.6). Results: There was a significant difference in SWE values between histologic grades of fibrosis (p = 0.003), with a positive correlation according to the grade (r = 0.7; p < 0.0001). Overall, a difference in SWD values between grades of inflammation was found (p = 0.009) but with a lack of correlation (r = 0.1; p = 0.67). Comparing inflammation grades 0−1 (median:13.6 m/s kHz [min; max; 8.4; 17.5]) versus grades 2−3 (16.3 m/s kHz [14.6; 24.2]) showed significant differences between the groups (p = 0.003). In the 30 individuals with a steatosis score of 0, ATI was measured in 23 cases with a median value of 0.56 dB/cm/MHz. Conclusion: Comprehensive ultrasound analysis was feasible to apply in children and has the potential to reflect the various components of liver affection non-invasively. Larger studies are necessary to conclude to what extent these image-based markers can classify the grade of fibrosis, inflammation and steatosis.

Liver Fibrosis Assessment by Viewing Sinusoidal Capillarization: US Molecular Imaging versus Two-dimensional Shear-Wave Elastography in Rats

Background US elastography is a first-line assessment of liver fibrosis severity; however, its application is limited by its insufficient sensitivity in early-stage fibrosis detection and its measurements are affected by inflammation. Purpose To assess the sensitivity of US molecular imaging (USMI) in early-stage liver fibrosis detection and to determine whether USMI can specifically distinguish fibrosis regardless of inflammation when compared with two-dimensional (2D) shear-wave elastography (SWE). Materials and methods USMI and 2D SWE were performed prospectively (January to June 2021) in 120 male Sprague-Dawley rats with varying degrees of liver fibrosis and acute hepatitis and control rats. Liver sinusoidal capillarization was viewed at CD34-targeted USMI and quantitatively analyzed by the normalized intensity difference (NID). Data were compared by using a two-sided Student t test or one-way analysis of variance. Linear correlation analyses were used to evaluate the relationships between collagen proportionate area values and NID and liver stiffness measurement (LSM) values. Receiver operating characteristic curves were used to assess the diagnostic performance in detecting liver fibrosis. Results Both NID and LSM values showed good linear correlation with collagen proportionate area values (r = 0.91 and 0.87, respectively). No difference was observed between the areas under the receiver operating characteristic curve in detecting stage F0-F1 between USMI and 2D SWE (0.97 vs 0.91, respectively; P = .20). USMI depicted liver fibrosis at an early stage more accurately than 2D SWE (area under the curve, 0.97 vs 0.82, respectively; P = .01). Rats with hepatitis had higher liver stiffness values than control rats (9.83 kPa ± 0.79 vs 6.55 kPa ± 0.38, respectively; P < .001), with no difference in the NID values between control rats and rats with hepatitis (6.75% ± 1.43 vs 6.74% ± 0.86, respectively; P = .98). Conclusion Sinusoidal capillarization viewed at US molecular imaging helped to detect early-stage liver fibrosis more accurately than two-dimensional shear-wave elastography and helped assess fibrosis regardless of inflammation. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Barr in this issue.

Liver and Spleen Stiffness Surveillance Through Elastography During and After Direct-Acting Antiviral Therapy in Patients With Chronic Hepatitis C

OBJECTIVES

Direct-acting antiviral agents achieve a high cure rate, resulting in early hepatic necroinflammatory resolution and sustained fibrosis regression. This study aimed to obtain longitudinal, concurrent within-subject measurements of liver stiffness (LS) and spleen stiffness (SS) and their correlates over time.

METHODS

Participants with hepatitis C (n = 592) receiving direct-acting antiviral-based therapy were monitored through point shear-wave elastography from the treatment baseline (TW0) across follow-up visits in terms of LS and SS.

RESULTS

Generalized linear mixed modeling indicated that all LS values (2301 visits) were negatively correlated with the follow-up times (all P < .05) from TW0 to 24 weeks (PW24) after the end of treatment (EOT) and positively correlated with baseline LS values (P < .001). The slopes of declines (preceding minus next) differed significantly (P < .001) between TW0-TW4 (treatment week 4) (0.060 [-0.050 to 0.225] meter/second/month [m/s/mo]) and TW4-EOT (0.010 [-0.030 to 0.075] m/s/mo). All SS values (1704 visits) were negatively correlated with time only at PW24 (P < .001) and positively correlated with baseline SS values (P < .001). The slopes of the SS values differed significantly (P < .001) only between EOT-PW12 (-0.010 [-0.110 to 0.083] m/s/mo) and PW12-PW24 (0.043 [-0.063 to 0.160] m/s/mo).

CONCLUSIONS

The biphasic fast-to-slow decline in LS occurred early in the on-treatment phase, which is consistent with the resolution of hepatic necroinflammation. The slow-to-fast decline in SS occurred off treatment. Future studies should investigate the association with regressions in liver fibrosis and portal hypertension.

A model based on two-dimensional shear wave elastography for acute-on-chronic liver failure development in patients with acutely decompensated hepatitis B cirrhosis

BACKGROUND

To evaluate the accuracy of two-dimensional (2D) shear wave elastography (SWE), develop and validate a novel prognostic model in predicting acute-on-chronic liver failure (ACLF) development in patients with acutely decompensated hepatitis B cirrhosis.

METHODS

This prospective cohort study enrolled 221 patients in the First Affiliated Hospital of Nanchang University from September 2019 to January 2021, and randomly assigned them to the derivation and validation cohorts (7:3 ratio). Ultrasound, 2D SWE, clinical and laboratory data were collected, and outcome (ACLF developed) was recorded during a 90-day follow-up period. We evaluated the ability of 2D SWE to predict the outcome, developed a model for predicting ACLF development in the derivation cohort, and assessed the model in the validation cohort.

RESULTS

2D SWE values were significantly higher in patients with ACLF development (P<0.05). The accuracy of 2D SWE in predicting the outcome was better than that of serum parameters of liver fibrosis (all P<0.05). The SWE model for ACLF development had good calibration and discrimination [concordance index (C-index): 0.855 and 0.840 respectively] in derivation and validation cohorts, outperforming serum prognostic scores (all P<0.05).

CONCLUSIONS

The SWE model, superior to serum prognostic scores in predicting ACLF development, could be a noninvasive tool to guide the individual management of patients with acutely decompensated hepatitis B cirrhosis.

Prevalence of nonalcoholic fatty liver disease using noninvasive techniques among children, adolescents, and youths living with HIV

OBJECTIVE

The prevalence of subclinical liver abnormalities is high among people with HIV, but data regarding perinatally HIV-infected children and adolescents (PHIV) are scarce. Noninvasive image techniques offer an opportunity to address nonalcoholic fatty liver disease (NAFLD) in a population in which the scores validated for adults have not been tested.

DESIGN

Prospective cross-sectional study including PHIV and uninfected controls.

METHODS

Noninvasive imaging techniques for the diagnosis of NAFLD and/or fibrosis were performed, and four scores to predict NAFLD were evaluated.

RESULTS

Seventy-six participants (59.2% women) with a median of 19 years old (interquartile range: 15.5-25.6) were included, 38 were PHIV and 38 were age and sex-matched controls. All HIV participants were on ART at the moment of inclusion, and 86.8% were virologically suppressed. A total of 11 PHIV and three controls were diagnosed with NAFLD (28.9% vs. 7.9%; P = 0.02) by noninvasive imaging techniques. The performance of scores based on clinical and analytical parameters was very poor. Although nonsignificant, overweight was more common among participants with NAFLD, who had a significantly higher BMI. Differences in HIV-related parameters between the groups were nonsignificant, except for the CD4+/CD8+ T-cells ratio, decreased among PHIV diagnosed with NAFLD (P = 0.04).

CONCLUSIONS

The prevalence of NAFLD was high (28.9%) among PHIV, and only partially explained by overweight and metabolic syndrome defining factors. The scores based on clinical and analytical parameters did not accurately identify participants at risk. Therefore, liver ultrasound assessment should be considered for the screening of NAFLD among PHIV in routine clinical practice.

Shear wave elastography using sound touch elastography and supersonic shear imaging for liver measurements: a comparative study

BACKGROUND

Measurements of liver stiffness obtained with 2-dimensional shear wave elastography (2D-SWE) have been widely used to clinically assess liver fibrosis. However, differences between different 2D-SWE systems can lead to confusion when interpreting measurements. This study investigated the variability between a recently released sound touch elastography (STE) system and a supersonic shear imaging (SSI) system and assessed the degree of intersystem discrepancy using the different liver stiffness value (LSV) thresholds recommended by the Society of Radiologists in Ultrasound (SRU) for assessing liver fibrosis.

METHODS

A total of 4,152 patients who had undergone STE and SSI on the same day were enrolled in this retrospective study. First, intrasystem agreement for STE and SSI was assessed. Then, intraclass correlation coefficients (ICCs) and the Bland-Altman method were used to assess intersystem variability for all cases, classified according to the thresholds recommended by the SRU. The effects of age, gender, and body-mass index (BMI) were evaluated using multivariate linear regression analysis and attributive intervals were computed for STE and SSI at each of the different thresholds.

RESULTS

The ICCs for STE and SSI intrasystem agreement were 0.94 [95% confidence interval (CI): 0.937-0.943; P<0.001] and 0.984 (95% CI: 0.984-0.985; P<0.001), respectively. The 95% limit of agreement (LOA) for all cases ranged from -6.96 to 7.44 kPa. The 95% LOA increased as the threshold values rose, and intersystem variability was obvious, even at the smallest threshold (the 95% LOA at values ≤5 kPa was -0.85 to 2.08 kPa, while that at values >17 kPa was -20.81 to 14.71 kPa). The adjusted R2 for age, gender, and BMI was only 0.018 (all P value <0.05).

CONCLUSIONS

There was clear variability between STE and SSI, in contrast with some previous studies with small sample sizes, and consistent with others. Intersystem variability increased with the elevation of the LSV thresholds recommended by the SRU. Gender and BMI had little effect on intersystem variability. Future research could compare STE and SSI in different liver diseases, assessing the feasibility of the SRU-recommended thresholds in proven pathologies and evaluating the test-retest repeatability.

Multiinstitutional Evaluation of the Liver Surface Nodularity Score on CT for Staging Liver Fibrosis and Predicting Liver-Related Events in Patients With Hepatitis C

BACKGROUND. In single-institution multireader studies, the liver surface nodularity (LSN) score accurately detects advanced liver fibrosis and cirrhosis and predicts liver decompensation in patients with chronic liver disease (CLD) from hepatitis C virus (HCV). OBJECTIVE. The purpose of this study was to assess the diagnostic performance of the LSN score alone and in combination with the (FIB-4; fibrosis index based on four factors) to detect advanced fibrosis and cirrhosis and to predict future liver-related events in a multiinstitutional cohort of patients with CLD from HCV. METHODS. This retrospective study included 40 consecutive patients, from each of five academic medical centers, with CLD from HCV who underwent nontargeted liver biopsy within 6 months before or after abdominal CT. Clinical data were recorded in a secure web-based database. A single central reader measured LSN scores using software. Diagnostic performance for detecting liver fibrosis stage was determined. Multivariable models were constructed to predict baseline liver decompensation and future liver-related events. RESULTS. After exclusions, the study included 191 patients (67 women, 124 men; mean age, 54 years) with fibrosis stages of F0-F1 (n = 37), F2 (n = 44), F3 (n = 46), and F4 (n = 64). Mean LSN score increased with higher stages (F0-F1, 2.26 ± 0.44; F2, 2.35 ± 0.37; F3, 2.42 ± 0.38; F4, 3.19 ± 0.89; p < .001). The AUC of LSN score alone was 0.87 for detecting advanced fibrosis (≥ F3) and 0.89 for detecting cirrhosis (F4), increasing to 0.92 and 0.94, respectively, when combined with FIB-4 scores (both p = .005). Combined scores at optimal cutoff points yielded sensitivity of 75% and specificity of 82% for advanced fibrosis, and sensitivity of 84% and specificity of 85% for cirrhosis. In multivariable models, LSN score was the strongest predictor of baseline liver decompensation (odds ratio, 14.28 per 1-unit increase; p < .001) and future liver-related events (hazard ratio, 2.87 per 1-unit increase; p = .03). CONCLUSION. In a multiinstitutional cohort of patients with CLD from HCV, LSN score alone and in combination with FIB-4 score exhibited strong diagnostic performance in detecting advanced fibrosis and cirrhosis. LSN score also predicted future liver-related events. CLINICAL IMPACT. The LSN score warrants a role in clinical practice as a quantitative marker for detecting advanced liver fibrosis, compensated cirrhosis, and decompensated cirrhosis and for predicting future liver-related events in patients with CLD from HCV.

Noninvasive diagnosis of periportal fibrosis in schistosomiasis mansoni: A comprehensive review

Schistosomiasis mansoni is a neglected disease and key public health problem, mainly due to its high prevalence, the scarcity of public policies, and the severity of some clinical forms. Periportal fibrosis (PPF) is the commonest complication of chronic schistosomiasis mansoni and its diagnosis requires different techniques. Even though wedge biopsy of the liver is considered the gold standard, it is not justified in non-surgical patients, and percutaneous liver biopsy may be informative but does not have sufficient sensitivity. Noninvasive PPF tests mostly include biological (serum biomarkers or combined scores) or physical assessments (imaging assessment of fibrosis pattern or tissue stiffness). Moreover, imaging techniques, such as ultrasound, computed tomography, magnetic resonance imaging, and elastography are applied not only to support the diagnosis of schistosomiasis, but also to assess and detect signs of portal hypertension and organ damage due to chronic schistosomiasis. A combination between a comprehensive history and physical examination with biomarkers for liver fibrosis and imaging methods seems to offer the best approach for evaluating these patients. In addition, understanding their strengths and limitations will allow a more accurate interpretation in the clinical context and can lead to greater accuracy in estimating the degree of fibrosis in patients with Schistosomiasis mansoni (S. mansoni) infection. This review will discuss the different noninvasive methods that are currently available for the evaluation of PPF in S. mansoni infection, and their application, advantages, and limitations in clinical practice.

Creation of an Inpatient Alcohol Liver Service Improves Early Liver Disease Detection in Patients With Alcohol Use Disorder

One of the most common and devastating complications of alcohol use disorder (AUD) is the development of alcohol-associated liver disease (ALD).¹ Unfortunately, outcomes of patients with ALD are poor, in large part because patients with ALD are diagnosed at a much later stage of disease compared with patients with other causes of liver disease.² Accordingly, earlier detection is critical in combating the high mortality associated with ALD. In this work, we sought to assess the feasibility and impact of evaluating high-risk patients with no prior documented liver disease for the presence of advanced ALD while admitted to the hospital.

Ultrasound elastography in the assessment of post-stroke muscle stiffness: a systematic review

Background

Post-stroke muscle stiffness is a major challenge in the rehabilitation of stroke survivors, with no gold standard in clinical assessment. Muscle stiffness is typically evaluated by the Modified Ashworth Scale or the Tardieu Scale; however, these can have low reliability and sensitivity. Ultrasound elastography is an advanced imaging technology that can quantitatively measure the stiffness of a tissue and has been shown to have good construct validity when compared to clinically assessed muscle stiffness and functional motor recovery.

Objective

The purpose of this article is to systematically review the literature regarding the change in muscle stiffness as measured by ultrasound elastography in stroke survivors.

Methods

Scopus, PubMed, Embase, CINAHL, MEDLINE and Cochrane Library were searched for relevant studies that assessed the change in stiffness of post-stroke muscle stiffness measured by ultrasound elastography following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

Results

In total, 29 articles were identified, using either strain elastography and shear wave elastography to measure the stiffness of muscles in stroke survivors, most frequently in the biceps and medial gastrocnemius muscles. The stiffness was typically higher in the paretic compared to the non-paretic or healthy control. Other variations that increased the stiffness include increasing the joint angle and introducing a passive stretch or muscle activation. The paretic muscle has also been assessed pre- and post-treatment demonstrating a decrease in stiffness.

Conclusion

Ultrasound elastography is a promising imaging technology for determining the muscle stiffness in stroke survivors with need for a standardized imaging protocol.

Quantitative Assessment of Portal Hypertension by Two-Dimensional Shear Wave Elastography in Rat Models of Nonalcoholic Fatty Liver Disease: Comparison With Four Composite Scores

Background

Measurement of hepatic venous pressure gradients is the gold standard for assessing portal hypertension (PH) but is invasive with potential complications. We aimed to assess the performance in liver and spleen stiffness measurement (LSM and SSM, respectively) by two-dimensional shear wave elastography (2D-SWE) and composite scores including liver stiffness-spleen diameter to platelet ratio score (LSPS), platelet (PLT) count/spleen diameter ratio (PSR), aspartate aminotransferase (AST)/alanine aminotransferase ratio (AAR), and AST-to-PLT ratio index (APRI) for diagnosing PH in nonalcoholic fatty liver disease (NAFLD) rat models.

Methods

Animal models with PH in NAFLD were established in 65 rats, which then underwent 2D-SWE measurements. Morphological and biological parameters were collected for calculation of four composite scores. Correlations of noninvasive methods with portal venous pressure were evaluated by Spearman correlation analysis. The area under the receiver operating characteristic curve (AUC) was used to assess the performance of noninvasive methods in predicting PH.

Results

LSM and SSM were significantly associated with portal venous pressure (r = 0.636 and 0.602, respectively; all P < 0.001). The AUCs of LSM and SSM in the diagnosis of PH were 0.906 (95% confidence interval [CI]:0.841–0.97) and 0.87 (95% CI:0.776–0.964), respectively, and were significantly higher than those in composite scores. The AUCs for LSPS, PSR, AAR, and APRI were 0.793, 0.52, 0.668, and 0.533, respectively, for diagnosing PH. The AUCs of the combined models of LSM and SSM, LSM and PLT, SSM and PLT, and LSM, SSM and PLT were 0.923, 0.913, 0.872, and 0.923, respectively. The four combined models showed no statistical differences compared to LSM and SSM in evaluating PH (all P > 0.05).

Conclusions

LSM and SSM by 2D-SWE can be used as promising noninvasive parameters for diagnosing PH in NAFLD and have higher accuracy than composite scores. The combined models, compared to LSM and SSM, did not significantly improve the performance in diagnosing PH.

Comparing shear wave elastography with liver biopsy in the assessment of liver fibrosis at King Hussein Medical Center

Background and study aims

The aim of this prospective study is to compare the sensitivity and specificity of the liver shear wave elastography to the golden standard liver biopsy in staging liver fibrosis.

Patients and methods

Ninety-five patients were included in this study. These patients were sent for liver biopsy as a possible living liver donor or because of different pathologies including viral and autoimmune hepatitis and congenital liver diseases. A shear wave elastography and US-guided liver biopsy were done at the same setting by one experienced radiologist. One experienced histopathologist, blinded to SWE results, read the specimens.

Results

We included 95 patients in the study with a mean age of 30 years (range 3–65 years). We had 15/95 (16%) patients with hepatitis B/C, 61/95 (64%) patients with another liver disease, and 19/95 (20%) were donors. The mean of liver stiffness measured by elastography in patients was 6.5±0.19 kPa. The mean liver stiffness measured by elastography in patients with F0–F1 fibrosis was 5.39 ± 0.62 kPa, F2 was 7.32 ± 0.41, at stage F3 was 8.46 ± 0.33, and in the F4 stage, it was 11.42 ± 2.8 kPa. We found a significant difference in the mean level of liver stiffness in different degrees of fibrosis (p = 0.0001).

Conclusion

The shear wave elastography could be used to assess liver fibrosis regardless of the cause.

Staging Fibrosis in Chronic Viral Hepatitis

Staging fibrosis accurately has always been a challenge in viral hepatitis and other liver diseases. Liver biopsy is an imperfect gold standard due to its intra and interobserver agreement limitations and additional characteristics such as its safety and cost. Hence, non-invasive tests have been developed to stage liver fibrosis. In addition to serological biomarkers, physical tests with reasonable accuracy are available and adopted in the daily clinic regarding viral hepatitis fibrosis staging. In this review, we discuss the published data regarding the staging of liver fibrosis in chronic hepatitis B and C, emphasizing non-invasive markers of fibrosis, both serological and physical. Moreover, we also discuss a persistent central gap, the evaluation of liver fibrosis after HCV cure.

Accuracy of B-mode ultrasound and ARFI elastography in predicting malignancy of canine splenic lesions

The objective was to evaluate the accuracy of B-mode ultrasonography and ARFI elastography in detecting malignancy in canine splenic lesions. Thirty-seven spleens with abnormalities (16 benign and 21 malignant) from dogs of different breeds and ages were evaluated. Echogenicity, echotexture, organ length and height were evaluated using B-mode. By ARFI elastography, tissue stiffness was evaluated qualitatively (elastogram) and quantitatively (measuring the shear wave velocity-SWV). Lesions were classified as diffuse, focal or multifocal (cranial, medial or caudal portion) and comparisons of the SWV between the injured and non-injured areas were performed. In the B-mode, no features were associated to malignancy (P > 0.05). In the elastogram, 35 spleens were non-deformable and 2 deformable, having no association with malignancy. The greater SWV was observed in malignant lesions (3.4 ± 0.6 m/s), followed by areas free from alterations (2.1 ± 0.3 m/s) and benign lesions (1.7 ± 0.5 m/s), with difference between groups (P < 0.0001). It was found that a SWV > 2.6 m/s indicates malignancy of canine splenic lesions (sensitivity of 95%, specificity of 100%, PPV of 100%, NPV of 94% and accuracy of 97%), concluding that ARFI elastography is a promising technique for differentiating malignancy in these lesions.

Liver fibrosis quantification

Liver fibrosis (LF) is the wound healing response to chronic liver injury. LF is the endpoint of chronic liver disease (CLD) regardless of etiology and the single most important determinant of long-term liver-related clinical outcomes. Quantification of LF is important for staging, to evaluate response to treatment and to predict outcomes. LF is traditionally staged by liver biopsy. However, liver biopsy is invasive and suffers from sampling errors when biopsy size is inadequate; therefore, non-invasive tests (NITs) have found important roles in clinical care. NITs include simple laboratory-based serum tests, panels of serum tests, and imaging biomarkers. NITs are validated against the liver biopsy and will be used in the future for evaluation of nearly all CLDs with invasive liver biopsy reserved for some cases. Both serum tests and some imaging biomarkers such as elastography are currently used clinically as surrogate markers for LF. Several other imaging biomarkers are still considered research and awaiting clinical application in the future. As the evaluation of imaging biomarkers will likely become the norm in the future, understanding pathogenesis of LF is important. Knowledge of properties measured by imaging biomarkers and its correlation with LF is important to understand the application of NITs by abdominal radiologists. In this review, we present a brief overview of pathogenesis of LF, spatiotemporal evolution of LF in different CLD, and severity assessment with liver biopsy. This will be followed by a brief discussion on properties measured by imaging biomarkers and their relationship to the LF.

Ultrasound score combined with liver stiffness measurement by sound touch elastography for staging liver fibrosis in patients with chronic hepatitis B: a clinical prospective study

Background

A noninvasive and precise diagnosis of liver fibrosis in patients with chronic hepatitis B (CHB) is crucial for establishing the optimal time and strategy of therapy and for predicting treatment response. This study aimed to assess the diagnostic performance of ultrasound (US) score and liver stiffness measurement (LSM) of sound touch elastography (STE) in diagnosing liver fibrosis stages and to investigate whether combining these methods would improve liver fibrosis staging.

Methods

US and STE examinations were performed in CHB patients included. Liver biopsy was used as a reference standard. A diagnostic marker with the optimal linear combination (LC) of US score and LSM of STE, namely LC marker, was established for noninvasive assessment of liver fibrosis stages. The diagnostic performance of the LC marker was evaluated by using receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC).

Results

A total of 291 subjects, including 242 patients with CHB and 49 healthy volunteers, were included. Correlation analysis showed that the correlation of liver fibrosis stages to the LC marker (Spearman's r=0.846, P<0.001) was higher than that of LSM (r=0.771, P<0.001) or US score (r=0.825, P<0.001) alone. The results showed that the overall diagnostic performance of the LC marker in predicting a fibrosis stage of ≥F1, ≥F2, ≥F3, and =F4 {AUCs: 0.943 [95% confidence interval (CI): 0.917-0.948], 0.906 (0.871-0.915), 0.953 (0.923-0.969), and 0.961 (0.922-0.973), respectively} were better than those of the US score [AUCs: 0.916 (0.883-0.948, P=0.014), 0.875 (0.835-0.915, P<0.001), 0.934 (0.898-0.969, P=0.001), and 0.918 (0.864-0.973, P<0.001), respectively] or LSM [AUCs: 0.858 (0.812-0.948, P<0.001), 0.867 (0.826-0.915, P=0.006), 0.930 (0.894-0.969, P<0.023), and 0.958 (0.918-0.973, P=0.778), respectively].

Conclusions

The LC marker with the optimal combination of LSM and US score may be considered as a promising diagnostic model for noninvasive staging of liver fibrosis.

Liver stiffness assessed by real-time two-dimensional shear wave elastography predicts hypersplenism in patients with Wilson's disease: a prospective study

Background

The current study aimed to explore the value of liver stiffness assessed by two-dimensional real-time shear wave elastography (2D-SWE) to predict hypersplenism occurrence in Wilson’s disease (WD) patients.

Methods

Ninety WD patients were enrolled in this prospective study between May 2018 and December 2018. Baseline clinical data and ultrasound imaging including 2D-SWE liver stiffness of WD patients were collected. After enrollment, patients had follow-ups for 24 months or until they developed hypersplenism. The hypersplenism risk factors were determined using Cox regressions and receiver operating characteristic curves (ROC).

Results

Twenty-nine (32.2%) patients developed hypersplenism. Age, portal vein diameter, and liver stiffness were independent hypersplenism risk factors in WD patients. The cutoff value of liver stiffness to predict hypersplenism was 10.45 kPa, with sensitivity and specificity of 75.9% and 73.8%, respectively. Patients were divided into two groups according to liver stiffness: ≥ 10.45 kPa (57.9% with hypersplenism) or < 10.45 kPa (13.5% with hypersplenism). The median time between enrollment and hypersplenism development was 15 months vs. 22 months (p < 0.001) for the two groups, respectively.

Conclusion

The measurement of liver stiffness by 2D-SWE can be a reliable hypersplenism predictor in WD patients. Therefore, dynamic monitoring of WD patients using 2D-SWE is crucial for the early diagnosis of hypersplenism.

Shear Wave Elastography in the Differentiation of Nonfibrotic Versus Fibrotic Liver Disease in Children: A Prospective Study With Histological Correlation

To evaluate the diagnostic accuracy of ultrasound shear wave elastography (SWE) prospectively and to determine cutoff value for nonfibrotic liver tissue in children with suspected or established liver disease.

Methods

In 90 consecutive pediatric patients, standardized 2D-SWE was performed during general anesthesia and free breathing. Liver stiffness was estimated with SWE followed by a percutaneous biopsy from the corresponding area. SWE values were compared with histology with fibrosis scored according to Batts & Ludwig classification (grade 0-4 = F0-F4) and to hepatic biomarkers.

Results

Four patients with SWE interquartile range (IQR)/median ≥ 30% kPa were excluded. The remaining 86 children (59% males) had a mean age = 10.2 years (0.1-18). The distribution of individuals with median (min;max) SWE values (kPa) within each fibrosis grade were; F0[n = 10; 5.0(3.4;6.3)], F1[n = 24; 5.0(3.6;8.7)], F2[n = 32; 5.8(3.5;13.4)], F3[n = 12, 7.5(4.0;14.4)], and F4[n = 8; 12.5(6.6;21.0)]. There was a significant difference between fibrosis grades (0.03 > P < 0.002) except between F0 and F1 respectively between F1 and F2. The AuROC differentiating F0-1 from F2-4 was 0.77(95% CI: 0.67-0.87). A cutoff SWE value of ≤4.5 kPa yielded 90% sensitivity and 68% specificity to rule out significant fibrosis (F2-F4). Out of the 18 children (21%) with SWE value ≤4.5 kPa, 12 had grade F0-1 and 6 had F2, although including some confounders for increased SWE measurements as steatosis/hepatitis/cholestasis.

Conclusions

2D-SWE ultrasound can reliably distinguish no/mild (F0/F1) from moderate/severe (F2-F4) fibrosis in children with suspected/established liver disease with good sensitivity and acceptable specificity. Our results show that in pediatric patients, when the indication for biopsy is to rule out significant fibrosis, SWE can be considered an alternative.

Diagnostic Performance of 2-D Shear Wave Elastography on the Evaluation of Hepatic Fibrosis with Emphasis on Impact of the Different Region-of-Interest Methods

The purpose of this study was to evaluate the impact of the different region-of-interest (ROI) methods of 2-D shear wave elastography (2-D SWE) on hepatic fibrosis diagnosis. In this retrospective study, 83 patients who underwent 2-D SWE with three ROI methods (a circle ROI, a box ROI and multiple ROIs in an elastogram) and transient elastography (TE) were included. Liver stiffness (LS) was measured five times with each ROI method. These LS values were compared, and their correlation with those obtained from TE was evaluated. The LS values obtained using the three different ROI methods differed statistically (p < 0.001). However, the LS values obtained using each ROI method of 2-D SWE were highly correlated with those obtained using TE (r > 0.7, p < 0.001). All three ROI methods of 2-D SWE had high areas under the receiver operating characteristic curve in diagnosing significant fibrosis and cirrhosis (0.841, 0.820 and 0.840, respectively; 0.962, 0.946 and 0.945, respectively). There were no significant differences in area under the receiver operating characteristic curve among the ROI methods of 2-D SWE. Regardless of the ROI method, 2-D SWE had high performance in diagnosing hepatic fibrosis.

Diagnostic efficacy of FibroScan for liver inflammation in patients with chronic hepatitis B: a single-center study with 1185 liver biopsies as controls

Background

Noninvasive diagnostic technologies that can dynamically monitor changes in liver inflammation are highly important for the management of chronic hepatitis B (CHB) patients and thus warrant further exploration. This study assessed the diagnostic efficacy of FibroScan for liver inflammation in CHB patients.

Methods

A total of 1185 patients were selected, and ultrasound-guided liver biopsy was performed within 1 month after the FibroScan test. The liver stiffness measurement (LSM), the reliability criteria (IQR/M) of LSM, the quality of liver biopsy (complete portal area, PA), and the liver inflammation grades were the main observation items of this study. With liver biopsy as the control, the diagnostic efficacy of FibroScan for liver inflammation in CHB patients was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

The grade of liver inflammation was positively correlated with the stage of fibrosis (rho = 0.829, P < 0.001). Different grades of inflammation will have significant rise in LSM values within the same fibrosis stage, and LSM values were positively correlated with liver inflammation grade and fibrosis stage, and the rho is 0.579 and 0.593 respectively (P < 0.001). Significant differences in the LSM of FibroScan were observed among different grades of liver inflammation (P < 0.0001). Liver biopsy (PA > 10) served as the control, and the cutoff point and the area under ROC curves (AUCs) of the LSMs for different inflammation grades were as follows: G2, 8.6 kPa, 0.775; G3 9.8 kPa, 0.818; and G4, 11.0 kPa; 0.832. With LSM cutoff values of 8.6 kPa, 9.8 kPa and 11.0 kPa, FibroScan showed certain diagnostic value for CHB patients with G2, G3 and G4 liver inflammation, especially those with G4 inflammation.

Conclusions

The grade of liver inflammation was positively correlated with the stage of fibrosis, different grades of inflammation will have significant rise in LSM values within the same fibrosis stage. In addition to liver fibrosis, FibroScan could evaluate liver inflammation in CHB patients in a noninvasive manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02108-0.

US Attenuation for Liver Fat Quantification: An AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with an estimated prevalence of up to 30% in the general population and higher in people with type 2 diabetes. The assessment of liver fat content is essential to help identify patients with or who are at risk for NAFLD and to follow their disease over time. The American Institute of Ultrasound in Medicine-RSNA Quantitative Imaging Biomarkers Alliance Pulse-Echo Quantitative Ultrasound Initiative was formed to help develop and standardize acquisition protocols and to better understand confounding factors of US-based fat quantification. The three quantitative US parameters explored by the initiative are attenuation, backscatter coefficient, and speed of sound. The purpose of this review is to present the current state of attenuation imaging for fat quantification and to provide expert opinion on examination performance and interpretation. US attenuation methods that need further study are outlined.

Shear wave speed measurement bias in a viscoelastic phantom across six ultrasound elastography systems: a comparative study with transient elastography and magnetic resonance elastography

Purpose

To quantify the bias of shear wave speed (SWS) measurements in a viscoelastic phantom across six different ultrasound (US) systems and to compare the SWS with those from transient elastography (TE) and magnetic resonance elastography (MRE).

Methods

A viscoelastic phantom of stiffness representing fibrotic liver or healthy thyroid was measured with nine (linear probe) and 10 (convex probe) modes of six different US-based shear wave elastography (SWE) systems using linear and convex probes. SWS measurements of three regions of interest were repeated thrice at two focal depths, coupling the probe to the phantom using a jig. An MRE system using three motion-encoding gradient frequencies of 60, 90, and 120 Hz and TE were also used to measure the stiffness of the phantom.

Results

The SWS from different SWE systems had mean coefficients of variation of 9.0–9.2% and 5.4–5.6% with linear and convex probes, respectively, in viscoelastic phantom measurement. The focal depth was a less significant source of SWS variability than the system. The total average SWS obtained with US-SWE systems was 19.9% higher than that obtained with MRE at 60 Hz, which is commonly used in clinical practice, and 31.5% higher than that obtained with TE using the M probe.

Conclusions

Despite the measurement biases associated with the SWE systems, biases were not necessarily consistent, and they changed with the probes used and depth measured. The SWS of the viscoelastic phantom obtained using different modalities increased according to the shear wave frequency used.

Noninvasive Diagnosis of Hepatocellular Carcinoma on Sonazoid-Enhanced US: Value of the Kupffer Phase

The aim of this study was to compare the diagnostic performance of Contrast-Enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) version 2017, which includes portal- and late-phase washout as a major imaging feature, with that of modified CEUS LI-RADS, which includes Kupffer-phase findings as a major imaging feature. Participants at risk of hepatocellular carcinoma (HCC) with treatment-naïve hepatic lesions (≥1 cm) were recruited and underwent Sonazoid-enhanced US. Arterial phase hyperenhancement (APHE), washout time, and echogenicity in the Kupffer phase were evaluated using both criteria. The diagnostic performance of both criteria was analyzed using the McNemar test. The evaluation was performed on 102 participants with 102 lesions (HCCs (n = 52), non-HCC malignancies (n = 36), and benign (n = 14)). Among 52 HCCs, non-rim APHE was observed in 92.3% (48 of 52). By 5 min, 73.1% (38 of 52) of HCCs showed mild washout, while by 10 min or in the Kupffer phase, 90.4% (47 of 52) of HCCs showed hypoenhancement. The sensitivity (67.3%; 35 of 52; 95% CI: 52.9%, 79.7%) of modified CEUS LI-RADS criteria was higher than that of CEUS LI-RADS criteria (51.9%; 27 of 52; 95% CI: 37.6%, 66.0%) (p = 0.0047). In conclusion, non-rim APHE with hypoenhancement in the Kupffer phase on Sonazoid-enhanced US is a feasible criterion for diagnosing HCC.

Two-dimensional shear wave elastography for sparing endoscopy screening in patients with HBV-related compensated advanced chronic liver disease

OBJECTIVES

To investigate the diagnostic performance of liver stiffness (LS) measured by 2D-SWE for predicting esophageal varices (EV) and high-risk varices (HRV) in patients with hepatitis B virus (HBV)-related compensated advanced chronic liver disease (cACLD).

METHODS

In total, 268 patients with HBV-related cACLD who underwent 2D-SWE and esophagogastroduodenoscopy (EGD) were retrospectively evaluated. The new criteria for ruling out HRV were tested in the training cohort with 175 patients and validated in the validation cohort with 93 patients.

RESULTS

The AUROCs of LS for predicting EV and HRV were 0.90(0.86-0.95) and 0.93(0.89-0.96) respectively. LS (OR, 1.64 (95% CI: 1.31-2.07); P < 0.0001), PLT (OR, 0.94 (95% CI: 0.91-0.97); P < 0.0001) and albumin (OR, 0.75 (95% CI: 0.62-0.90); P = 0.02) were independent factors for the presence of HRV. The Baveno VI criteria of LS < 20 kPa and PLT > 150 × 10⁹ /L saved 15.1%-17.1% EGD screening with 0-4.3% HRV miss rate. LS < 16 kPa and PLT > 60 × 10⁹ /L spared 51.4%-52.7% EGD screening with 3.8%-4.3% HRV miss rate.

CONCLUSION

Baveno VI criteria is suitable for 2D-SWE to rule out HRV. LS < 16 kPa and PLT > 60 × 10⁹ /L could be a reliable model for ruling out HRV in patients with HBV-related cACLD.

Shear-Wave Dispersion Slope of the Liver: Effect of Study Protocol and Ascites on the Measurement Applicability

This study aimed to evaluate the shear-wave dispersion (SWD) scanning protocol including the minimum number of measurements and better size of the region of interest (ROI), as well as the influence of ascites on the measurement applicability. Patients who had undergone serial SWD examinations between July 2019 and December 2020 were included. In patients with chronic liver disease (group A), two different ROI sizes were applied, and at least 10 measurements were repeated to determine the minimum number of measurements and better ROI size. In patients with liver failure (group B), failure and unreliable results were compared between patients with and without ascites. A minimum of five measurements when using a 20-mm ROI and six measurements when using a 10-mm ROI were required. Compared with using a 20-mm ROI, a 10-mm ROI showed a higher unreliable rate. The failure and unreliable rates of SWD in patients with ascites were significantly higher than those in patients without ascites. SWD examination required at least five measurements when using a 20-mm ROI and six measurements when using a 10-mm ROI. A larger ROI was associated with higher reliability, and ascites influenced the failure and reliability of the SWD measurement.

Brazilian Society of Hepatology and Brazilian College of Radiology practice guidance for the use of elastography in liver diseases

In 2015 the European Association for the Study of Liver Diseases (EASL) and the Asociación Latinoamericana para el Estudio del Hígado (ALEH) published a guideline for the use of non-invasive markers of liver disease. At that time, this guideline focused on the available data regarding ultrasonic-related elastography methods. Since then, much has been published, including new data about XL probe use in transient elastography, magnetic resonance elastography, and non-invasive liver steatosis evaluation. In order to draw evidence-based guidance concerning the use of elastography for non-invasive assessment of fibrosis and steatosis in different chronic liver diseases, the Brazilian Society of Hepatology (SBH) and the Brazilian College of Radiology (CBR) sponsored a single-topic meeting on October 4th, 2019, at São Paulo, Brazil. The aim was to establish specific recommendations regarding the use of imaging-related non-invasive technology to diagnose liver fibrosis and steatosis based on the discussion of evidence-based topics by an organizing committee of experts. It was submitted online to all SBH and CBR members. The present document is the final version of the manuscript that supports the use of this new technology as an alternative to liver biopsy.

Advances in liver US, CT, and MRI: moving toward the future

Over the past two decades, the epidemiology of chronic liver disease has changed with an increase in the prevalence of nonalcoholic fatty liver disease in parallel to the advent of curative treatments for hepatitis C. Recent developments provided new tools for diagnosis and monitoring of liver diseases based on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), as applied for assessing steatosis, fibrosis, and focal lesions. This narrative review aims to discuss the emerging approaches for qualitative and quantitative liver imaging, focusing on those expected to become adopted in clinical practice in the next 5 to 10 years. While radiomics is an emerging tool for many of these applications, dedicated techniques have been investigated for US (controlled attenuation parameter, backscatter coefficient, elastography methods such as point shear wave elastography [pSWE] and transient elastography [TE], novel Doppler techniques, and three-dimensional contrast-enhanced ultrasound [3D-CEUS]), CT (dual-energy, spectral photon counting, extracellular volume fraction, perfusion, and surface nodularity), and MRI (proton density fat fraction [PDFF], elastography [MRE], contrast enhancement index, relative enhancement, T1 mapping on the hepatobiliary phase, perfusion). Concurrently, the advent of abbreviated MRI protocols will help fulfill an increasing number of examination requests in an era of healthcare resource constraints.

Assessment of chronic liver disease by multiparametric ultrasound: results from a private practice outpatient facility

PURPOSE

To assess chronic liver disease (CLD) using multiparametric US in a private practice setting in a cohort of patients with increased skin-to-liver distance.

METHODS

110 consecutive patients with increased skin-to-liver distance scheduled for US assessment of CLD were reviewed for study completion time, liver stiffness values (LS), attenuation imaging, and shear wave dispersion slope. The ROI was placed 2 cm below the liver capsule. The study included patients with NAFLD/NASH (68), hepatitis C (30), prior Fontan surgery (1), elevated liver function tests (5), alcohol abuse (3), hepatitis B (2), and primary biliary cirrhosis (1). IQR/M values were obtained. Comparison of less experienced sonographers (LES) and more experienced sonographers (MES) were evaluated through Student's t test for independent data. Pearson coefficient r of correlation among quantitative variables was calculated.

RESULTS

The mean time to perform the exam was 129.7 ± 62.1 s. There was a statistically significant difference between LES and MES. The mean IQR/M for LS was 12.3 ± 5.5% m/s. Overall, in a cohort of difficult patients, 4.5% of LS values were not reliable. Fat quantification using attenuation imaging had a mean value of 0.60 ± 0.15 dB/cm/MHz (range 0.35-0.98 cm/dB/MHz) with an IQR/M of 14.7 ± 9.2%. Less reliable measurements of steatosis were obtained in 4.5% of patients. The mean shear wave dispersion slope was 12.74 ± 4.05 (m/s)/kHz (range 7.7-27.5 (m/s)/kHz) with an IQR/M of 38.7 ± 20.2% (range 3-131%). 20.9% of patients had values suggestive of compensated advanced chronic liver disease (cACLD).

CONCLUSION

Multiparametric US can provide assessment of CLD in less than 3 min in most patients and identify patients at risk for cACLD.

Targeting plasma cells with daratumumab aids in the treatment of post-transplant autoimmune-like hepatitis

Antibody-mediated autoimmune-like hepatitis is a rare and challenging occurrence after hematopoietic cell transplant (HCT). We present the case of a 16-year-old male patient with Ph+ ALL who underwent matched sibling donor HCT and developed autoimmune-like hepatitis after receiving ponatinib for post-HCT maintenance, evidenced by marked plasma cell infiltrate on liver biopsy. He was successfully treated with steroids and daratumumab, an anti-CD38-monoclonal antibody. The dramatic response in this patient warrants expanded investigation of daratumumab for plasma cell-mediated disorders post-HCT. It further highlights that identifying mechanisms of immune-mediated injury can allow for directed therapy and limit exposure to broad immune suppression.

Hemodynamic analysis of hepatic arteries for the early evaluation of hepatic fibrosis in biliary atresia

BACKGROUND AND OBJECTIVE

Hepatic fibrosis is the prominent characteristic of biliary atresia (BA), may even progress continually after Kasai procedure (KP). BA, as a devastating pediatric hepatic disease, mainly leads to newborn cholestasis, even liver cirrhosis, eventually hepatic failure. Earlier diagnosis of hepatic fibrosis, which used to be detected by liver biopsy commonly, is consistent with better outcomes of KP. Due to potential risks and uncertainty of liver biopsy, it is an urge to seek a safer and more precise evaluation method as alternative. The purpose of this study is to investigate the hemodynamics of hepatic artery (HA) in hepatic fibrosis of early BA based on computational fluid dynamics (CFD) for evaluating the value of CFD for hepatic fibrosis diagnosis.

METHODS

40 patients were divided into three groups, including the control group, the abnormal liver function group and the mild to moderate hepatic fibrosis group. CFD was applied to quantify primary hemodynamic parameters of HA and related arteries, including blood flow distribution ratio (FDR), pressure, wall shear stress (WSS) and energy loss (EL). Statistical analyses were also performed to compare the differences amongst these above groups.

RESULTS

With the progression of hepatic fibrosis, the increasing tendency of hemodynamic parameters values of HA and related arteries were observed. Values of FDR, pressure, WSS and EL of the mild to moderate group was higher than those of the control group and the abnormal liver function group. There were significant differences on FDR_AA, FDR_HA and EL between the control group and the mild to moderate hepatic fibrosis group (t = 0.037, 0.030 and <0.001, P < 0.05).

CONCLUSION

Significant variations of HA hemodynamics acquired by CFD between the control group and the mild to moderate hepatic fibrosis group demonstrated the relationship between the progression of hepatic fibrosis and the hemodynamic disorder, and suggested that CFD had the potential to assist the diagnosis of hepatic fibrosis in early BA.

Liver stiffness measured by virtual touch quantification predicts the occurrence of posthepatectomy refractory ascites in patients with hepatocellular carcinoma

PURPOSE

This study assessed the significance of measuring liver stiffness using virtual touch quantification before hepatectomy to predict posthepatectomy refractory ascites.

METHODS

A total of 267 patients with hepatocellular carcinoma who underwent hepatectomy were prospectively analyzed. Liver stiffness was defined as the median value of the virtual touch quantification (Vs; m/s) by acoustic radio-force-impulse-based virtual touch.

RESULTS

A multivariate analysis showed that Vs and the aspartate aminotransferase-to-platelet ratio index were independent risk factors for postoperative refractory ascites (odds ratio = 3.27 and 3.08, respectively). The cutoff value for Vs was 1.52 m/s (sensitivity: 59.5%, specificity: 88.6%) as determined by the analysis of the receiver-operating characteristic curve, and the area under the receiver-operating characteristic curve was 0.79. The cutoff value for the aspartate aminotransferase-to-platelet ratio was 0.952 (sensitivity: 65.5%, specificity: 82.9%), and the area under the receiver-operating characteristic curve was 0.75.

CONCLUSIONS

Vs is an independent risk factor for refractory ascites after hepatectomy. The measurement of liver stiffness by virtual touch quantification before hepatectomy can help estimate the risk of postoperative refractory ascites. Nonsurgical treatments should be considered for the management of patients who are at high risk for refractory ascites.

2D-shear wave elastography: number of acquisitions can be reduced according to clinical setting

Background

The factors affecting intra-operator variability of two-dimensional shear wave elastography (2D-SWE) have not been clearly established. We evaluated 2D-SWE variability according to the number of measurements, clinical and laboratory features, and liver stiffness measurements (LSM).

Methods

At least three LSM were performed in 452 patients who underwent LSM by 2D-SWE (supersonic shear imaging) out of an initial database of 1650 patients. The mean value of the three LSM was our best measurement method. Bland–Altman plots were used to evaluate intra-operator variability when considering only one, or the first two measurements. Variability was assessed by taking the absolute value of the difference between the first LSM and the mean of the three LSM. Logistic regression was used to assess the factors associated with the highest tertile of variability.

Results

The limit of agreement was narrower with the mean of the first and second measurements than with each measurement taken separately (− 2.83 to 2.99 kPa vs. − 5.86 to 6.21 kPa and − 5.77 to 5.73 kPa for the first and second measurement, respectively). A BMI ≥ 25 kg/m² and a first LSM by 2D-SWE ≥ 7.1 kPa increased the odds of higher variability by 3.4 and 3.9, respectively. Adding a second LSM didn’t change the variability in patients with BMI < 25 and a first LSM by 2D-SWE < 7.1 kPa.

Conclusions

Intra-operator variability of LSM by 2D-SWE increases with both a high BMI and high LSM value. In patients with BMI < 25 kg/m² and a first LSM < 7.1 kPa we recommend performing only one LSM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-021-01090-7.

New frontiers in liver ultrasound: From mono to multi parametricity

Modern liver ultrasonography (US) has become a “one-stop shop” able to provide not only anatomic and morphologic but also functional information about vascularity, stiffness and other various liver tissue properties. Modern US techniques allow a quantitative assessment of various liver diseases. US scanning is no more limited to the visualized plane, but three-dimensional, volumetric acquisition and consequent post-processing are also possible. Further, US scan can be consistently merged and visualized in real time with Computed Tomography and Magnetic Resonance Imaging examinations. Effective and safe microbubble-based contrast agents allow a real time, dynamic study of contrast kinetic for the detection and characterization of focal liver lesions. Ultrasound can be used to guide loco-regional treatment of liver malignancies and to assess tumoral response either to interventional procedures or medical therapies. Microbubbles may also carry and deliver drugs under ultrasound exposure. US plays a crucial role in diagnosing, treating and monitoring focal and diffuse liver disease. On the basis of personal experience and literature data, this paper is aimed to review the main topics involving recent advances in the field of liver ultrasound.

The Diagnostic Accuracy of LOGIQ S8 and E9 Shear Wave Elastography for Staging Hepatic Fibrosis, in Comparison with Transient Elastography

BACKGROUND

The aim of this study was to evaluate the usefulness of two different types of 2-dimensional shear wave elastography (2D-SWE) for predicting liver fibrosis stages in comparison to transient elastography (TE), using a histologic METAVIR scoring system as the reference method.

METHODS

A total of 203 patients with chronic liver disease were prospectively enrolled in the study. Two different 2D-SWEs (LOGIQ S8 and E9 systems, GE Healthcare, Chalfont St Giles, UK) were assessed for liver stiffness in patients with chronic liver diseases. Patients received 2D-SWE examinations with the S8 and E9 systems, and also underwent TE (FibroScan^®, Echosens, France) tests and liver biopsies on the same day.

RESULTS

The most common etiology of chronic liver disease was non-alcoholic fatty liver disease (28.7%), followed by chronic hepatitis B (25.1%). Liver fibrosis stages consisted of F0 (22.6%), F1 (29.7%), F2 (16.9%), F3 (12.8%) and F4 (17.9%). Overall, S8 and E9 were well correlated with the histologic fibrosis stages. The optimal cut-off values for S8 and E9 to differentiate significant fibrosis (≥F2) were 6.70 kPa and 6.42 kPa, respectively, while the cut-off values for S8 and E9 in distinguishing liver cirrhosis were 9.15 kPa and 8.88 kPa, respectively. Among the 195 patients who had successful measurements in both S8 and E9, liver stiffness showed good inter-equipment correlation (ICC: 0.900, p < 0.001). Regarding diagnostic ability, upon comparison (FibroScan^®), there were no significant differences between 2D-SWEs and TE for detecting every stage of liver fibrosis.

CONCLUSION

In comparison to TE, 2D-SWE with LOGIQ S8 and E9 (GE Healthcare) are useful non-invasive tools for predicting significant fibrosis and liver cirrhosis.

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.

APS (Age, Platelets, 2D Shear-Wave Elastography) Score Predicts Hepatocellular Carcinoma in Chronic Hepatitis B

Background Two-dimensional (2D) shear-wave elastography (SWE) has been considered to be useful in predicting hepatocellular carcinoma (HCC) development in patients with chronic hepatitis B (CHB). Purpose To develop a risk model using 2D SWE to predict HCC in patients with CHB and to compare its predictive value with that of other models. Materials and Methods Patients with biopsy-proven CHB who underwent US and 2D SWE between April 2011 and December 2015 were enrolled in this study. After 2D SWE and biopsy were performed, the patients received regular follow-up for the detection of HCC. The scoring system was developed by dividing the parameters of the Cox proportional hazards model by the smallest parameter and simplifying the assigned points to integers. The predictive performance of the new score was compared with that of other scores. Results Among the 654 patients (mean age, 37 years; range, 30-43 years; 510 men), 26 developed HCC. The variables of age, platelet count, and liver stiffness measurement at 2D SWE were weighted to develop the so-called APS score, with a cutoff of 60 showing the best discrimination for HCC risk. The APS score (area under the receiver operating characteristic curve [AUC], 0.89) was superior to that of the Chinese University HCC prediction score constructed from age, albumin level, bilirubin level, hepatitis B virus (HBV) DNA level, and cirrhosis (AUC, 0.70; P = .005) and slightly higher than that of the guide with age, gender, HBV DNA level, core promoter mutations, and cirrhosis, or GAG-HCC score (AUC, 0.82; P = .052). In patients who underwent transient elastography, the AUC of the APS score was 0.79, compared with 0.82 for the modified risk estimation for HCC in CHB, or mREACH-B, score (P = .05). The APS score performed better in patients regardless of whether antiviral treatment was used, inflammation grade was low or high, or alanine aminotransferase levels were normal or high (all P > .05). Conclusion The APS score based on only the patient's baseline liver stiffness measurement at two-dimensional shear-wave elastography, age, and platelet count is valuable for predicting hepatocellular carcinoma in patients with chronic hepatitis B. © RSNA, 2021 Online supplemental material is available for this article.

High resolution flow (HR Flow) and glazing flow in cases of hepatic flow changes: Comparison to color-coded Doppler sonography (CCDS)

AIM

To evaluate the possibilities of flow detection using high resolution flow (HR Flow) and Glazing Flow technique in patients with liver parenchymal changes and flow changes in comparison to colour coded Doppler sonography (CCDS).

MATERIAL AND METHODS

All examinations were performed using a multi frequency matrix convex probe with high resolution technique (SC6-1U/Resona7, Mindray, Shenzhen, China) by one experienced examiner to evaluate the venous, portal venous and arterial liver flow with digital documentation of the dynamic flow parameters like peak systolic flow, end-diastolic flow and resistance index. For liver parenchymal stiffness changes shear wave elastography was performed with at least 10 measurements. By two independent readers an elevation was performed to evaluate the image quality and the degree of flow artefacts, from 0 = not available to 5 points with excellent image quality without flow artefacts.

RESULTS

All 40 patients (24 men, 16 women, age 27-83 years, mean 56±5 years) showed morphology changes from B-Mode of the liver parenchyma to inhomogeneous tissue with higher stiffness evaluated by the shear wave elastography (1.45 m/s up to 2.79 m/s±1.79 m/s, considering F1 up to F4 fibrosis) and in 15 cases histopathologically proven liver cirrhosis. In 9 cases after non-acute thrombosis flow reduction of the portal vein was the reason for the diameter less than 5 mm. Flow parameters for the venous flow were between 8 cm/s up to 29 cm/s, mean 14±4 cm/s, for the hepatic portal vein 5 cm/s up to 57 cm/s, mean 17±5 cm/s, for the hepatic artery systolic flow between 50 cm/s up to 127±33 cm/s, end-diastolic flow from 22 cm/s up to 47 cm/s±8 cm/s. Resistance index for the hepatic artery was between 0.41 up to 0.73, mean 0.67±0.25. The image quality for CCDS over all cases was evaluated for CCDS between 1 up to 4. The mean quality was 2.5±0.5, for HR Flow in combination with Glazing flow 3±0.5, with significant differences for the 2 readers (P <  0.01).

CONCLUSION

Combination of HR Flow with Glazing Flow could be helpful to evaluate morphological und hemodynamic changes of liver arterial flow, portal venous and venous flow. Reduction of flow artefacts in combination with a higher image quality could be helpful for optimizing the digital measurements also for follow up examinations.

Role of Ultrasound for Chronic Liver Disease and Hepatocellular Carcinoma Surveillance

Ultrasound plays a vital role in the evaluation of patients with chronic liver disease and in hepatocellular carcinoma (HCC) surveillance in populations at risk for developing HCC. Semiannual ultrasound for HCC surveillance is universally recommended by all liver societies around the world. Advanced ultrasound techniques, such as elastography and contrast-enhanced ultrasound, offer additional benefits in imaging evaluation of chronic liver disease. Major benefits of ultrasound include its high safety profile and relatively low cost.

Ultrasound shear wave elastography: does it add value to gray-scale ultrasound imaging in differentiating biliary atresia from other causes of neonatal jaundice?

BACKGROUND

Neonatal/infantile jaundice is relatively common, and most cases resolve spontaneously. However, in the setting of unresolved neonatal cholestasis, a prompt and accurate assessment for biliary atresia is vital to prevent poor outcomes.

OBJECTIVE

To determine whether shear wave elastography (SWE) alone or combined with gray-scale imaging improves the diagnostic performance of US in discriminating biliary atresia from other causes of neonatal jaundice over that of gray-scale imaging alone.

MATERIALS AND METHODS

Infants referred for cholestatic jaundice were assessed with SWE and gray-scale US. On gray-scale US, two radiology readers assessed liver heterogeneity, presence of the triangular cord sign, hepatic artery size, presence/absence of common bile duct and gallbladder, and gallbladder shape; associated interobserver correlation coefficients (ICC) were calculated. SWE speeds were performed on a Siemens S3000 using 6C2 and 9 L4 transducers with both point and two-dimensional (2-D) SWE US. Both univariable and multivariable analyses were performed, as were receiver operating characteristic curves (ROC) and statistical significance tests (chi-squared, analysis of variance, t-test and Wilcoxon rank sum) when appropriate.

RESULTS

There were 212 infants with biliary atresia and 106 without biliary atresia. The median shear wave speed (SWS) for biliary atresia cases was significantly higher (P<0.001) than for non-biliary-atresia cases for all acquisition modes. For reference, the median L9 point SWS was 2.1 m/s (interquartile range [IQR] 1.7-2.4 m/s) in infants with biliary atresia and 1.5 m/s (IQR 1.3-1.9 m/s) in infants without biliary atresia (P<0.001). All gray-scale US findings were significantly different between biliary-atresia and non-biliary-atresia cohorts (P<0.001), intraclass correlation coefficient (ICC) range 0.7-1.0. Triangular cord sign was most predictive of biliary atresia independent of other gray-scale findings or SWS - 96% specific and 88% sensitive. Multistep univariable/multivariable analysis of both gray-scale findings and SWE resulted in three groups being predictive of biliary atresia likelihood. Abnormal common bile duct/gallbladder and enlarged hepatic artery were highly predictive of biliary atresia independent of SWS (100% for girls and 95-100% for boys). Presence of both the common bile duct and the gallbladder along with a normal hepatic artery usually excluded biliary atresia independent of SWS. Other gray-scale combinations were equivocal, and including SWE improved discrimination between biliary-atresia and non-biliary-atresia cases.

CONCLUSION

Shear wave elastography independent of gray-scale US significantly differentiated biliary-atresia from non-biliary-atresia cases. However, gray-scale findings were more predictive of biliary atresia than elastography. SWE was useful for differentiating biliary-atresia from non-biliary-atresia cases in the setting of equivocal gray-scale findings.

Two-dimensional shear wave elastography for screening varices in Asian patients with primary biliary cholangitis

Objectives: The presence of varices affects the survival of patients with primary biliary cholangitis (PBC). The aim of this study is to assess the criteria based on liver stiffness (LS) measured by two-dimensional shear wave elastography (2D-SWE) and platelet count (PLT), and recently published noninvasive models for triaging PBC patients.Methods: 231 patients with PBC who underwent EGD and 2D-SWE examination were enrolled. Areas under the receiver-operating characteristic curve (AUROC) were used to assess the performance of 2D-SWE for predicting all-size varices and high-risk varices. All-size varices and high-risk varices miss rate < 10% and <5%, respectively, were acceptable for screening varices.Results: The AUROCs of LS for predicting all-size varices and high-risk varices were 0.87 (95%CI: 0.82-0.91) and 0.84 (95%CI: 0.74-0.86), respectively. LS <25 kPa and PLT >110 × 10⁹/L spared 46.3% EGD screening, with 3.7% high-risk varices miss rate and 8.4% all-size varices miss rate. One hundred and sixteen (50.2%) patients met the Newcastle varices in PBC score (cutoff, 0.5), with 4.3% high-risk varices miss rate and 11.2% all-size varices miss rate.Conclusion: The criteria based on LS and PLT are useful for triaging PBC patients. LS <25 kPa and PLT >110 × 10⁹/L could be the optimal criteria for screening varices.