Adherence to quality criteria improves concordance between transient elastography and ElastPQ for liver stiffness assessment-A multicenter retrospective study

Derivation of Splenic Stiffness in Subjects with Normal Liver Stiffness and No Vascular Liver Disease Using Transient Elastography with a Spleen-Dedicated Module: A Large Cross Sectional Study

BACKGROUND

Liver and splenic stiffness measurements (LSM and SSM) are useful to predict varices and clinical decompensation in cirrhosis. SSM values are highly variable and overlapping and no guidelines exists on what constitutes normal SSM, that might limit interpretation of results.

METHODS

Consecutive subjects with LSM < 6 kPa and reliable SSM (FibroScan630 Expert device with spleen-dedicated module) and no vascular liver disease were analysed for significant correlations of SSM values with age, sex, BMI, portal and splenic vein diameter, splenic diameter, liver fat and diabetes. Based on timeline of SSM, subjects were randomly assigned in 70:30 ratio into derivation [n = 502] and validation subset [n = 214].

RESULTS

Of 7200 subjects with simultaneous reliable LSM and SSM, 715 fulfilled the selection criteria (mean age: 43.8 ± 12.8 years, 67.2% male, mean BMI-26.4 ± 4.5 kg/m2). The mean SSM was 22.6 ± 5.8 kPa (c10-c90 percentile range: 15.2-31.3 kPa) and followed the normal distribution curve. In the derivation subset, mean SSM for males was higher than female (23.06 ± 6.2 vs. 21.78 ± 5.93 kPa; p = 0.028). SSM value correlated with LSM (r = 0.454, p = 0.001). Mean SSM in subjects with LSM 3-4, 4.1-5 and 5.1-6 kPa were 21.7 ± 5.8, 22.27 ± 5.67 and 23.76 ± 5.88 kPa (p value = 0.001). There was no difference in SSM based on age, BMI, diabetes and liver fat on ultrasound. Above results hold true for subjects in validation subset.

CONCLUSION

SSM range in subjects with normal LSM and no vascular liver disease using spleen-dedicated module varies from 15.2 to 31.3 kPa, values being higher in male and not affected by Age, BMI, spleen size, liver fat and diabetes. Our results may serve as reference point in evaluation of SSM in compensated advanced liver disease patients.

Understanding confounding factors allows for accurate interpretation of liver stiffness measurements by ElastQ, a novel 2D shear wave elastography technique

PURPOSE

Liver stiffness measurement (LSM) using vibration-controlled transient elastography (VCTE) or two-dimensional shear wave elastography (2D-SWE) is recommended to assess the risk of liver fibrosis and advanced chronic liver disease. Even though both techniques measure liver stiffness, their numerical results often diverge. Confounders and reliability criteria for 2D-SWE have not been systematically investigated.

MATERIALS AND METHODS

We prospectively recruited participants with paired LSM by VCTE and the novel 2D-SWE technique ElastQ (Philips) in three European tertiary centers. The following parameters were recorded: sex, age, body mass index (BMI), etiology, laboratory markers of liver damage and function, as well as cholestasis, LSM by VCTE and controlled attenuation parameter (CAP), interquartile range (IQR)/median for VCTE-LSM and ElastQ-LSM, and the skin-to-liver capsule distance.

RESULTS

We included 840 participants: 447 (53.2%) males; median age 57.0 [IQR:19.0] years; median BMI 25.4 [6.0] kg/m2; median VCTE-LSM 7.25 [9.2] kPa; median ElastQ-LSM 6.7 [5.4] kPa. On uni- and multivariable modeling (adjusted for LSM), we found that the discrepancy increased with liver stiffness and markers of disease severity. Skin-to-liver capsule distance and BMI affected VCTE-LSM more compared to ElastQ-LSM and significantly increased the discordance between the two measurements.

CONCLUSION

The discrepancy of ElastQ-LSM to VCTE-LSM increases with liver stiffness and disease severity. BMI and skin-to-liver capsule distance increase the discrepancy between VCTE- and ElastQ-LSM but affect ElastQ-LSM less. The quality criterion IQR/median ≤ 30% indicates reliable ElastQ-LSM.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

Image-guided point-shear-wave elastography: a valid and reliable technique for liver fibrotic staging

PURPOSE

Despite progressive implementation of image-guided point-shear wave elastography (pSWE) in guidelines as an alternative to transient elastography for the staging of fibrotic liver disease, pSWE is not widely adopted in clinical workflow. More information on reliability and validity of pSWE systems is needed. Therefore, we performed a phantom study to evaluate the validity and reliability of pSWE with ultrasound systems.

METHODS

Validity and reliability of pSWE measurements from three ultrasound systems were evaluated. Measurements were performed on an elasticity phantom with reference elasticities of 7 ± 1 (low) (median ± interquartile range (IQR)), 14 ± 2 (medium) and 26 ± 3 (high) kPa. Measurements were repeated in tenfold for each reference at 2, 3 and 4 cm depth. Results were considered valid when median elasticity ± IQR was between the uncertainty limits (IQR) for each reference elasticity value and reliable when IQR/median < 0.30.

RESULTS

pSWE with the systems provided valid results for all reference elasticities and focal depths, except for overestimation of high reference elasticity at 2 and 4 cm depth for one system (41.5 ± 4.3 and 39.0 ± 1.2 kPa, respectively). Measurements were reliable with a maximum IQR/median of 0.13, well below the guideline of IQR/median < 0.30.

DISCUSSION

The results support the use of pSWE as an alternative to invasive or non-image guided noninvasive techniques for liver fibrotic staging.

CONCLUSIONS

pSWE with ultrasound systems from different vendors is valid and reliable and can therefore be implemented to optimize clinical workflow by performing imaging and elastography simultaneously.

Prospective evaluation of liver shearwave elastography measurements with 3 different technologies and same day liver biopsy in patients with chronic liver disease

BACKGROUND

Most ultrasound-based methods for assessing liver fibrosis still need further validation with liver biopsy used as gold standard to assess their accuracy.

AIMS

To assess accuracy of three shear wave elastography (SWE) methods: 1) Philips Elast Point Quantification (ElastPQTM), 2) Siemens Virtual TouchTM Quantification (VTQ) acoustic radiation force impulse (ARFI), and 3) transient elastography (TE) measured by Echosens FibroscanTM.

METHODS

160 patients underwent liver stiffness measurements (LSM) with three SWE methods immediately prior to liver biopsy.

RESULTS

The number of LSM required for reliable studies could be reduced to 6 for ElastPQ and to 7 for VTQ from standard recommendations of 10. Significant fibrosis and interquartile range/median (IQR/M)> 30 were independent predictors for lower reliability for detection of liver fibrosis. Ordinal logistic regression corrected for age showed that there was a significant interaction between steatosis (p = 0.008) and lobular inflammation (p = 0.04) and VTQ (ARFI) and between lobular inflammation and TE (p = 0.006).

CONCLUSIONS

We showed variations in SWE measurements using different ARFI technologies. TE and ElastPQ achieved good diagnostic performance, whereas VTQ showed lower diagnostic accuracy. The number of measurements required for reliable studies can be reduced to 6 for ElastPQ and to 7 for VTQ, which have important clinical implications.

The Role of ElastPQ in Assessing Liver Stiffness for Non-Alcoholic Fatty Liver Disease in Patients Treated with Atypical Antipsychotic Drugs

Objective

To evaluate the role of elastography point quantification (ElastPQ) for the quantitative assessment of stiffness in the fatty liver disease in mental disorder patients and to provide a noninvasive detection method for non-alcoholic fatty liver (NAFLD) caused by atypical antipsychotics drugs (AAPDs).

Methods

A total number of 168 mental disorder patients treated with AAPDs and 58 healthy volunteers were enrolled in this study. All the subjects underwent ultrasound and ElastPQ tests. The basic data of the patients were analyzed.

Results

BMI, liver function, and the value of ElastPQ were considerably higher in the patient group than that in the healthy volunteers. The values of liver stiffness obtained by ElastPQ were increased gradually from 3.48(3.14-3.81) kPa in the normal liver to 8.15(6.44-9.88) in the severe fatty liver. The receiver operating characteristic (ROC) for the diagnosis of fatty liver with ElastPQ were 0.85, 0.79, 0.80, and 0.87 for the diagnosis of normal, mild, moderate, and severe steatosis, respectively, with a sensitive/specificity of 79%/76.4%, 85.7%/78.3%, 86.2%/73%, and 81.3%/82.1%, correspondingly. Moreover, ElastPQ in the olanzapine group was higher than those in the risperidone and aripiprazole groups (5.11(3.83-5.61) kPa vs 4.35(3.63-4.98) kPa, P < 0.05; 5.11(3.83-5.61) kPa vs 4.79(4.18-5.24) kPa, P < 0.05). After one-year treatment, the value of ElastPQ was 4.43(3.85-5.22) kPa, but it was 5.81(5.09-7.33) kPa in patients treated for more than three years. This value increased with treatment prolongation (P < 0.05).

Conclusion

ElastPQ is a real-time, quantitative method for assessing the stiffness of NAFLD. The liver stiffness value could be varied in the different stages of fatty liver. Olanzapine has a considerable influence on liver stiffness. The long-term use of AAPDs can increase the stiffness value of fatty liver.

Point Shear Wave Elastography by ElastPQ for Fibrosis Screening in Patients with NAFLD: A Prospective, Multicenter Comparison to Vibration-Controlled Elastography

BACKGROUND

Since nonalcoholic fatty liver disease (NAFLD) has become the leading cause of liver disease in the Western world, clinicians need reliable noninvasive tools for the identification of NAFLD-associated fibrosis. Limited evidence on the performance of the novel shear wave elastography technique Elast-PQ (EPQ) in NAFLD is available.

METHOD

In this prospective, European multinational study we assessed the diagnostic accuracy of EPQ using vibration-controlled transient elastography (VCTE) as a reference standard.

RESULTS

Among 353 NAFLD patients, 332 (94.1%) fulfilled reliability criteria of VCTE and EPQ (defined by IQR/median ≤0.3; 41.3% female, mean age: 59 [IQR: 16.5], mean BMI: 29.0 (7.1)). 4/353 (1.1%) and 17/353 (4.8%) had unreliable VCTE and EPQ measurements, respectively. VCTE-based NAFLD fibrosis stages were F0/F1: 222(66.9%), F2: 41 (12.3%), F3: 30 (9.1%), F4: 39 (11.7%). We found a strong correlation (Pearson R=0.87; p<0.0001) and concordance (Lin's concordance correlation coefficient =0.792) of EPQ with VCTE. EPQ was able to identify NAFLD-fibrosis risk with the following EPQ cutoffs: ≥6.5 kPa for significant fibrosis (≥F2) (≥1.47 m/s; sensitivity: 78%; specificity: 95%; AUROC: 0.94), ≥6.9 kPa for advanced fibrosis (≥F3) (≥1.52 m/s; sens.: 88%, spec.: 89%; AUROC: 0.949), and ≥10.4 kPa for cirrhosis (F4) (≥1.86 m/s; sens.: 87%; spec.: 94%; AUROC: 0.949).

CONCLUSION

The point shear wave elastography technique EPQ shows excellent correlation to and concordance with VCTE. EPQ can reliably exclude NAFLD fibrosis <6.0 kPa (<1.41 m/s) and indicate a high risk of advanced fibrosis ≥10.4 kPa (≥1.86 m/s).

How to Identify Advanced Fibrosis in Adult Patients with Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH) Using Ultrasound Elastography-A Review of the Literature and Proposed Multistep Approach

Non-alcoholic fatty liver disease (NAFLD), and its progressive form, non-alcoholic steatohepatitis (NASH), represent, nowadays, real challenges for the healthcare system. Liver fibrosis is the most important prognostic factor for NAFLD, and advanced fibrosis is associated with higher liver-related mortality rates. Therefore, the key issues in NAFLD are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. We critically reviewed the ultrasound (US) elastography techniques for the quantitative characterization of fibrosis, steatosis, and inflammation in NAFLD and NASH, with a specific focus on how to differentiate advanced fibrosis in adult patients. Vibration-controlled transient elastography (VCTE) is still the most utilized and validated elastography method for liver fibrosis assessment. The recently developed point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) techniques that use multiparametric approaches could bring essential improvements to diagnosis and risk stratification.

Comparison of point-shear wave elastography (ElastPQ) and transient elastography (FibroScan) for liver fibrosis staging in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIMS

ElastPQ is a point shear wave elastography technique used to non-invasively assess liver fibrosis. We compared liver stiffness measurements (LSM) by ElastPQ and fibroscan transient elastography (F-TE) in a cohort of patients with non-alcoholic fatty liver disease (NAFLD). We further evaluated the performance of ElastPQ in a subgroup of patients with available liver histology.

MATERIALS AND METHODS

We included patients with NAFLD who presented in a dedicated multidisciplinary clinic. Anthropometric parameters, blood tests and elastography measurements were obtained using F-TE and ElastPQ as part of routine clinical care.

RESULTS

We enrolled 671 patients with NAFLD, mean age 55.8 ± 13 years, body mass index (BMI) 31.5 ± 5.7 kg/m² , 56.6% males, 41% diabetes, 53.7% hypertension, 68% dyslipidaemia. ElastPQ showed an excellent correlation with F-TE (Spearman's r = 0.80, p < .001), which was better for mild/moderate stages of fibrosis. Independent predictors of a >2 kPa discrepancy between the two techniques were a larger waist circumference and F-TE ≥10 kPa. In the subgroup of 159 patients with available histology, ElastPQ showed similar diagnostic accuracy with F-TE in staging liver fibrosis (ElastPQ area under the curves 0.84, 0.83, 0.86 and 0.95, for F ≥ 1, F ≥ 2, F ≥ 3 and F = 4 respectively). Optimal cut-off values of ElastPQ for individual fibrosis stages were lower than those of F-TE.

CONCLUSIONS

ElastPQ shows an excellent correlation with F-TE in patients with NAFLD, which was better for lower LSM. The optimal cut-off values of ElastPQ are lower than those of F-TE for individual stages of fibrosis. ElastPQ has similar diagnostic accuracy to F-TE for all stages of fibrosis.

Comparison of point shear wave elastography and transient elastography in the evaluation of patients with NAFLD

PURPOSE

To compare point shear wave elastography (pSWE, ElastPQ®) and transient elastography (TE) with Liver Biopsy in order to evaluate fibrosis stage in non-alcoholic fatty liver disease (NAFLD).

METHODS

Our prospective study from September 2017 to October 2020 included 50 consecutively enrolled patients with NAFLD (52.2 ± 13.0 years, 32 male). All patients underwent clinical evaluation, B-mode ultrasound, pSWE, TE and liver biopsy in a single evaluation. The clinical, laboratory and liver biopsy data were compared with liver stiffness (LS) measurement obtained with pSWE and TE. TE and pSWE diagnostic accuracy for the diagnosis of the different fibrosis stages were evaluated using the area under receiver operating characteristic curve (AUROC).

RESULTS

Only fibrosis stage was independently associated with TE and pSWE. The median liver stiffness measurement for fibrosis stages F0, F1, F2, F3, and F4 using TE was 4.8 (4.7-6.1) kPa, 5.5 (4.4-7.3) kPa, 7.7 (6.1-9.1) kPa, 9.9 (8.8-13.8) kPa, and 20.2 kPa, respectively. The corresponding median liver stiffness measurement using pSWE was 4.2 (4.0-4.8) kPa, 4.7 (4.2-5.8) kPa, 5.1 (4.1-6.9) kPa, 8.5 (5.2-13.3), and 15.1 kPa, respectively. The AUROC of TE for diagnosis of fibrosis stage F1, ≥ F2, ≥ F3, and F4 were 0.795, 0.867, 0.927, and 0.990, respectively. The corresponding AUROC of pSWE was 0.717, 0.733, 0.908, and 1.000, respectively. No association was observed with other histological parameters.

CONCLUSION

TE was significantly better than pSWE for the diagnosis of fibrosis stage ≥ F2. No statistically significant differences were found between TE and pSWE AUROC of fibrosis stage ≥ F1, ≥ F3, and F4.

Noninvasive Assessment of Liver Fibrosis with ElastPQ in Patients with Chronic Viral Hepatitis: Comparison Using Histopathological Findings

Chronic viral hepatitis is a major cause of chronic liver disease leading to liver fibrosis. This study aimed to assess the diagnostic performance of elastography point quantification (ElastPQ), transient elastography (TE), and aspartate aminotransferase-to-platelet count ratio index (APRI) for the staging of liver fibrosis in patients with chronic viral hepatitis using histopathological findings as a reference standard. For 122 patients with chronic viral hepatitis, diagnostic performance was evaluated using area under the receiver operating characteristic curve (AUROC) analysis and correlations were determined using Spearman’s correlation coefficient. The AUROC of ElastPQ for the diagnosis of the fibrosis stage ≥ F2 was 0.917 with a cut-off value of 3.935. There was a significant positive correlation between the different stages of histologic liver fibrosis and stiffness values obtained using ElastPQ, TE, and APRI (ρ = 0.556, ρ = 0.657, ρ = 0.375, respectively; p < 0.001). ElastPQ showed a higher diagnostic accuracy than APRI, resembling that of TE; AUROC values of ElastPQ, TE, and APRI were 0.917, 0.964, and 0.896, respectively, for a fibrosis stage ≥ F2. ElastPQ is a promising noninvasive technique with a diagnostic accuracy comparable with that of TE for the evaluation of liver fibrosis in patients with chronic viral hepatitis.

Two-dimensional shear wave elastography predicts survival in advanced chronic liver disease

OBJECTIVE

Liver stiffness measurement (LSM) is a tool used to screen for significant fibrosis and portal hypertension. The aim of this retrospective multicentre study was to develop an easy tool using LSM for clinical outcomes in advanced chronic liver disease (ACLD) patients.

DESIGN

This international multicentre cohort study included a derivation ACLD patient cohort with valid two-dimensional shear wave elastography (2D-SWE) results. Clinical and laboratory parameters at baseline and during follow-up were recorded. LSM by transient elastography (TE) was also recorded if available. The primary outcome was overall mortality. The secondary outcome was the development of first/further decompensation.

RESULTS

After screening 2148 patients (16 centres), 1827 patients (55 years, 62.4% men) were included in the 2D-SWE cohort, with median liver SWE (L-SWE) 11.8 kPa and a model for end stage liver disease (MELD) score of 8. Combination of MELD score and L-SWE predict independently of mortality (AUC 0.8). L-SWE cut-off at ≥20 kPa combined with MELD ≥10 could stratify the risk of mortality and first/further decompensation in ACLD patients. The 2-year mortality and decompensation rates were 36.9% and 61.8%, respectively, in the 305 (18.3%) high-risk patients (with L-SWE ≥20 kPa and MELD ≥10), while in the 944 (56.6%) low-risk patients, these were 1.1% and 3.5%, respectively. Importantly, this M10LS20 algorithm was validated by TE-based LSM and in an additional cohort of 119 patients with valid point shear SWE-LSM.

CONCLUSION

The M10LS20 algorithm allows risk stratification of patients with ACLD. Patients with L-SWE ≥20 kPa and MELD ≥10 should be followed closely and receive intensified care, while patients with low risk may be managed at longer intervals.

Elastography for Pediatric Chronic Liver Disease: A Review and Expert Opinion

In adults with chronic liver diseases, ultrasound and magnetic resonance shear wave elastography (SWE) can replace liver biopsy in several clinical scenarios. Several guidelines on the use of ultrasound SWE for the adult population have been published. However, the number of publications in the pediatric population is limited, and available guidelines on SWE do not specifically address pediatric chronic liver diseases. In this article, we review the literature on the use of SWE for pediatric chronic liver diseases and provide expert opinion on how to use SWE, both ultrasound and magnetic resonance techniques, in the pediatric population.

Establishing Reliability Criteria for Liver ElastPQ Shear Wave Elastography (ElastPQ-SWE): Comparison Between 10, 5 and 3 Measurements

PURPOSE

 ElastPQ is a new elastography technique for non-invasive liver fibrosis staging. However, it does not have validated reliability criteria. We tested the reliability of a different number of measurements in patients with chronic liver disease and explored whether the application of quality criteria improves the diagnostic performance.

MATERIALS AND METHODS

 All patients underwent liver stiffness assessment (LSM) with ElastPQ and Fibroscan (F-TE). The mean, median, standard deviation (SD) and interquartile range (IQR) of 10, 5 and 3 measurements were retrospectively collected for each patient and compared to each other. Liver histology was available in a subset of patients.

RESULTS

 Overall, 400 patients met the inclusion criteria. Non-alcoholic fatty liver disease (NAFLD) was the most represented etiology (75 %), followed by primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH). The correlation of medians was significantly better between 10 and 5 measurements than between 10 and 3. The difference of medians was significant only in the comparison between 10 and 3 measurements. The correlation between ElastPQ and F-TE was equally good for 10 and 5 measurements and significantly improved after an IQR/median ≤ 30 % was applied. The diagnostic performance of ElastPQ was better with the median value of 10 and 5 measurements and improved if LSM values were obtained with IQR/M ≤ 30 %.

CONCLUSION

 The median value of 5 valid LSMs suffices for the reliable estimation of liver stiffness using ElastPQ. The quality criterion of IQR/M ≤ 30 % should also be followed when using this technique.

Spleen Stiffness Probability Index (SSPI): A simple and accurate method to detect esophageal varices in patients with compensated liver cirrhosis

INTRODUCTION AND OBJECTIVES

Recent findings pointed out that even low-risk esophageal varices (EVs) are markers of severe prognosis. Accordingly, we analyzed spleen stiffness (SS) as a non-invasive method to predict EVs of any grade in a cohort of patients with compensated liver cirrhosis.

METHOD

We measured SS and liver stiffness (LS) using point-Shear-Wave Elastography (pSWE) with Philips Affiniti 70 system in 210 cirrhotic patients who had undergone endoscopic screening for EVs. We compared SS and LS predictive capability for EVs of any grade.

RESULTS

SS was higher in cirrhotic patients with EVs if compared to patients without EVs (p<0.001). The cut-off analysis detected 31kPa (100% sensitivity and negative predictive value) as the value to rule-out EVs and 69kPa (100% specificity and positive predictive value) to rule-in EVs. Besides, we developed the Spleen Stiffness Probability Index (SSPI), that can provide a probability of presence/absence of EVs. SSPI was the best model according to all discriminative and calibration metrics (AIC=120, BIC=127, AUROC=0.95, Pseudo-R2=0.74). SS demonstrated higher correlation with spleen bipolar diameter and spleen surface (r=0.52/0.55) if compared to LS (r=0.30/0.25) - and with platelet count as well (r=0.67 vs r=0.4).

CONCLUSION

SS showed significantly higher performance than other parameters, proving to be the best non-invasive test in the screening of EVs: by directly applying SS cut-off of 31kPa, our department could have safely avoided endoscopy in 36% of patients. Despite cut-off analyses, it was possible to create a probability model that could further stratify low-risk from high-risk patients (for any grade of EVs).

Noninvasive assessment of liver fibrosis in a real-world cohort of patients with known or suspected chronic liver disease using 2D-shear wave elastography

OBJECTIVES

We aimed to investigate the diagnostic accuracy of liver stiffness measurement (LSM) by 2D-shear wave elastography (2D-SWE, GE, Logiq E9) in patients with known or suspected chronic liver disease and to define cutoff values for the different stages of fibrosis.

METHODS

First, we retrospectively enrolled 21 patients in a pilot study and validated the results in a prospective cohort of 70 patients between May 2017 and February 2019. In all patients, LSM and liver biopsy were performed. We analyzed the diagnostic accuracy of LSM for the different fibrosis stages and examined the impact of additional clinical parameters on LSM.

RESULTS

The success rate of LSM was 88.6%. In the prospective cohort, optimal cutoff values for F ≥ 1, F ≥ 2, F ≥ 3 and F = 4 were 6.24, 7.86, 8.05 and 10.74 kPa [area under the receiver operating characteristic curve (AUROC) 0.831, 0.913, 0.996 and 0.954]. In both cohorts and in the subgroup of patients with nonalcoholic fatty liver disease (NAFLD) (n = 35), a cutoff value of 8.05 kPa differentiates patients with advanced fibrosis (F ≥ 3) and patients with no or mild fibrosis (F0-F2) with high diagnostic accuracy (AUROC 0.995-1.000). Parameters such as age, sex, BMI, bilirubin- and alanine aminotransferase-level had no significant impact on LSM.

CONCLUSION

LSM by 2D-SWE is an excellent method to differentiate between patients with advanced fibrosis (F ≥ 3) and patients with no or mild fibrosis (F ≤ 2). We were able to show this also in a subgroup of patients with NAFLD.

Comparison of liver stiffness measurements by a 2D-shear wave technique and transient elastography: results from a European prospective multi-centre study

OBJECTIVES

To compare liver stiffness measurement (LSM) provided by Canon 2D-shear wave elastography (2D-SWE) and transient elastography (TE), the latter being the reference method.

METHODS

Prospective study conducted in four European centres from 2015 to 2016 including patients with various chronic liver diseases who had LSMs with both 2D-SWE and TE on the same day. Median of 10 valid measurements (in kPa) was used for comparison using paired t test, Pearson correlation, intraclass correlation coefficient (ICC) and Bland-Altman plot. The ability of 2D-SWE to stratify patient according to recognised LSM-TE thresholds was assessed by ROC curve analysis.

RESULTS

Six hundred forty patients were scanned, where 593 (92.7%), 572 (89.4%) and 537 (83.9%) had reliable LSMs by TE, 2D-SWE and both combined, respectively. In the latter (n = 537, 310 [57.7%] male, mean 55.3 ± 14.8 years), median LSM-TE and LSM-2D-SWE had a mean of 10.1 ± 9.4 kPa (range 2.4-75) and 9.1 ± 6.1 kPa (range 3.6-55.7) (paired t test: p < 0.001), respectively. These were significantly correlated (Pearson r = 0.932, p < 0.001, ICC 0.850 (0.825-0.872), bias 0.99 ± 4.33 kPa [95% limits of agreement - 9.48 to + 7.49] with proportional error towards higher LSM values). LSM-2D-SWE values significantly increased with TE categories (ANOVA: p < 0.001). AUROCs ranged from 0.935 ± 0.010 (95% CI 0.910-0.954) to 0.973 ± 0.009 (95% CI 0.955-0.985), resulting in correct classification of 390/537 (73%) patients. Three 2D-SWE measurements were sufficient for reliable LSMs.

CONCLUSION

LSM using 2D-SWE correlates well with TE. It tends to underestimate higher stages of liver fibrosis but correctly classifies the majority of patients. It may be used in TE-derived algorithms to manage patients.

KEY POINTS

• Liver stiffness measurement (LSM) by 2D-shear wave elastography (2D-SWE) and transient elastography (TE) are strongly correlated. • 2D-SWE shows proportionately lower LSM values compared to TE, particularly with the higher LSM range. • Three individual measurements by 2D-SWE are sufficient to assess LSM reliably.

Assessing Baveno VI criteria with liver stiffness measured using a new point-shear wave elastography technique (BAVElastPQ study)

BACKGROUND AND AIMS

To date, no study has explored the potential role of ElastPQ, a novel point-SWE technique, in the assessment of clinically significant portal hypertension. The aim of our study was to determine a liver stiffness (LS) cut-off value measured by ElastPQ and laboratory parameters that could help to identify those patients who can safely avoid screening endoscopy.

METHODS

Data were collected on 1422 patients who underwent ElastPQ measurement from January 2013 to January 2016 in our Department. Inclusion criteria were a LS value of ≥7 kPa, an upper gastrointestinal endoscopy within 12 months and a diagnosis of compensated chronic liver disease. Exclusion criteria were history of decompensated liver disease, evidence of porto-spleno-mesenteric vein thrombosis and non-cirrhotic portal hypertension. Varices were graded as low-risk varices (grade <2) or varices needing treatment (VNT, grade ≥2).

RESULTS

The study included 195 patients (120 [61%] HCV, 171 [88%] Child-Pugh A). Varices were present in 35% cases, with 10% prevalence of VNT. According to ROC curve analysis, LS measurement and platelet count were evaluated as predictors of VNT. Overall, 75/195 (38%) met the 'BAVElastPQ' criteria (that is, LS < 12 kPa and platelet count >150 000/μL). Within this group, 11/75 (15%) had any grade of varices and only 1/75 (1%) had VNT. The BAVElastPQ criteria gave sensitivity of 0.95, specificity of 0.42, positive predictive value of 0.15 and negative predictive value of 0.99.

CONCLUSIONS

The BAVElastPQ criteria correctly identified 99% of patients without VNT. By applying such criteria, we could have potentially avoided 38% of surveillance endoscopies in our cohort.

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

This multidisciplinary update of the Society of Radiologists in Ultrasound consensus statement on liver elastography incorporates the large volume of new information available in the literature since the initial publication. The recommended procedure for acquiring stiffness measurements is reviewed. There has been substantial improvement in the acoustic radiation force impulse (ARFI) technology-most notably the addition of a quality assessment of the shear wave propagation. Due to the efforts of the Quantitative Imaging Biomarkers Alliance, or QIBA, the variability of liver stiffness measurements between systems had decreased. There are now effective treatments for hepatitis B and hepatitis C, and follow-up after effective treatment should be based on the use of the delta change of the value obtained at viral eradication or suppression. Because the detection of compensated advanced chronic liver disease (cACLD) is very important, the new guidelines are made based on the probability of cACLD for given stiffness values. The panel recommends a vendor-neutral rule of four for interpretation for ARFI techniques. This new method simplifies interpretation of liver stiffness results and is more clinically relevant.

Comparing point shear wave elastography (ElastPQ) and transient elastography for diagnosis of fibrosis stage in non-alcoholic fatty liver disease

BACKGROUND AND AIM

Transient elastography (TE) and point shear wave elastography (pSWE) are noninvasive methods to diagnose fibrosis stage in patients with chronic liver disease. The aim of this study is to compare the accuracy of the two methods to diagnose fibrosis stage in non-alcoholic fatty liver disease (NAFLD) and to study the intra-observer and inter-observer variability when the examinations were performed by healthcare personnel of different backgrounds.

METHODS

Consecutive NAFLD patients who underwent liver biopsy were enrolled in this study and had two sets each of pSWE and TE examinations by a nurse and a doctor on the same day of liver biopsy procedure. The medians of the four sets of pSWE and TE were used for evaluation of diagnostic accuracy using area under receiver operating characteristic curve (AUROC). Intra-observer and inter-observer variability was analyzed using intraclass correlation coefficients.

RESULTS

Data for 100 NAFLD patients (mean age 57.1 ± 10.2 years; male 46.0%) were analyzed. The AUROC of TE for diagnosis of fibrosis stage ≥ F1, ≥ F2, ≥ F3, and F4 was 0.89, 0.83, 0.83, and 0.89, respectively. The corresponding AUROC of pSWE was 0.80, 0.72, 0.69, and 0.79, respectively. TE was significantly better than pSWE for the diagnosis of fibrosis stages ≥ F2 and ≥ F3. The intra-observer and inter-observer variability of TE and pSWE measurements by the nurse and doctor was excellent with intraclass correlation coefficient > 0.96.

CONCLUSION

Transient elastography was significantly better than pSWE for the diagnosis of fibrosis stage ≥ F2 and ≥ F3. Both TE and pSWE had excellent intra-observer and inter-observer variability when performed by healthcare personnel of different backgrounds.

Transient elastography reliably estimates liver fibrosis in autoimmune hepatitis

Aim of the study

Autoimmune hepatitis (AIH) may result in liver fibrosis and cirrhosis. While the gold standard for staging fibrosis is biopsy, transient elastography (TE) represents a non-invasive alternative. TE has been validated in several chronic liver diseases, but no data exist to establish an association between histologic fibrosis on biopsy and TE liver stiffness measurements among a United States cohort of AIH patients.

Material and methods

We conducted a retrospective cohort study of 53 AIH patients who received TE assessment and liver biopsy. Histologic fibrosis was classified as advanced (F3-F4) or mild/moderate (F0-F2). Liver stiffness by TE was measured in kilopascals (kPa). We performed a score test for trend to test the association between histologic fibrosis stage and increasing TE kPa categories. Analyses incorporated probe type (medium or extra-large) and body mass index (BMI). Linear regression was used to generate predicted associations between median kPa and histologic fibrosis score with the medium probe.

Results

The cohort was primarily female (83%) with median age 56.3 years. Increasing kPa category was associated with worsening fibrosis stage when using the medium probe (p = 0.04), but not the extra-large probe (p = 0.40). BMI, however, differed between these groups (median 25.8 vs. 33.1, respectively, p < 0.001). In adjusted linear regression, increasing median kPa corresponded well to worsening fibrosis stage (p = 0.003).

Conclusions

In a United States AIH cohort, increasing TE kPa measurements are associated with worsening histologic fibrosis staging. While medium probe performance was superior to the extra-large probe, significant variation in BMI between groups may explain this difference.

Diagnostic performance of a point shear wave elastography (pSWE) for hepatic fibrosis in patients with autoimmune liver disease

BACKGROUND & AIMS

Elastography point quantification is a convenient method for measuring liver stiffness. It can be performed simultaneously with conventional ultrasonography. This study aimed to evaluate its diagnostic performance for assessing hepatic fibrosis in patients with autoimmune liver disease (AILD), including autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC).

METHODS

The diagnostic performance of elastography point quantification (ElastPQ) was evaluated and compared with that of serum fibrosis markers, including the aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4), using the receiver operating characteristics analysis with histologic evaluation as the reference standard.

RESULTS

In 49 AIH patients, sensitivity and specificity of ElastPQ were 93.6% and 44.4%, respectively, for significant fibrosis (≥ F2, cutoff 4.47 kPa), and 63.6% and 86.8% for cirrhosis (F4, cutoff 9.28 kPa). In 41 PBC patients, they were 81.8% and 73.3%, respectively, for significant fibrosis (≥ F2, cutoff 5.56 kPa), and 100% and 81.6%, respectively, for advanced fibrosis (≥ F3, cutoff 6.04 kPa). The areas under the receiver operating characteristic curves of ElastPQ for significant fibrosis (0.77, 95% CI 0.67-0.86) and cirrhosis (0.81, 95% CI 0.65-0.96) were higher than those of APRI and FIB-4 in AILD patients. According to the multivariable analysis, histological activity, steatosis, and body max index (BMI) were not significant factors that influenced the result of ElastPQ.

CONCLUSIONS

ElastPQ exhibited better diagnostic performance-without the influence of confounding factors-for assessing hepatic fibrosis in AILD patients than serum fibrosis markers.

Elastography-based screening for esophageal varices in patients with advanced chronic liver disease

Elastography-based liver stiffness measurement (LSM) is a non-invasive tool for estimating liver fibrosis but also provides an estimate for the severity of portal hypertension in patients with advanced chronic liver disease (ACLD). The presence of varices and especially of varices needing treatment (VNT) indicates distinct prognostic stages in patients with compensated ACLD (cACLD). The Baveno VI guidelines suggested a simple algorithm based on LSM < 20 kPa (by transient elastography, TE) and platelet count > 150 G/L for ruling-out VNT in patients with cACLD. These (and other) TE-based LSM cut-offs have been evaluated for VNT screening in different liver disease etiologies. Novel point shear-wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) methodologies for LSM have also been evaluated for their ability to screen for “any” varices and for VNT. Finally, the measurement of spleen stiffness (SSM) by elastography (mainly by pSWE and 2D-SWE) may represent another valuable screening tool for varices. Here, we summarize the current literature on elastography-based prediction of “any” varices and VNT. Finally, we have summarized the published LSM and SSM cut-offs in clinically useful scale cards.

Multiparametric ultrasound in liver diseases: an overview for the practising clinician

Ultrasound (US) is usually the first and most commonly used tool in the diagnostic algorithm for liver disease. It is widely available, non-invasive and offers a real-time assessment of the liver in several anatomic planes, using different US modalities such as greyscale imaging, Doppler, elastography and contrast-enhanced US. This multiparametric ultrasound (MPUS) provides more information of the examined structures and allows for a faster and more accurate diagnosis, usually at the point of care, thus reducing the requirement for some invasive and more expensive methods. Current data on the MPUS in hepatology are summarised in this review, mostly focused on its use for non-invasive staging of liver fibrosis, detection and classification of portal hypertension and oesophageal varices, prognosis in chronic liver diseases and characterisation of focal liver lesions (FLLs). Based on the available data, we propose practical algorithms for clinical use of MPUS in chronic liver disease and FLL.