Quantitative diagnosis of early acute compartment syndrome using two-dimensional shear wave elastography in a rabbit model.

PURPOSE: This study explored the association of the elasticity modulus and shear wave velocity (SWV) of the tibialis anterior muscle, as measured by two-dimensional shear wave elastography (2D-SWE), with the intracompartmental pressure (ICP) determined using the Whitesides method in a New Zealand rabbit model of acute compartment syndrome (ACS). Additionally, it evaluated the viability of 2D-SWE as a noninvasive, quantitative tool for the early detection of ACS. METHODS: An ACS model was established through direct external compression by applying pressure bandaging to the lower legs of 15 New Zealand rabbits using neonatal blood pressure cuffs. Another five animals represented a non-modeled control group. To measure the elasticity modulus and SWV of the tibialis anterior muscles, 2D-SWE was employed. Blood oxygen saturation, serum creatine kinase (CK), and myoglobin levels were monitored. Subsequently, the anterior tibial compartment was dissected, and the tibialis anterior was removed for hematoxylin and eosin staining to assess muscle injury. RESULTS: The elasticity modulus and SWV of the tibialis anterior muscle increased with compression duration, as did serum CK and myoglobin levels. ICP was strongly positively correlated with these parameters, particularly mean velocity (r=0.942, P<0.001) and CK (r=0.942, P<0.001). Blood oxygen saturation was negatively correlated with ICP (r=-0.887, P<0.001). Histological analysis indicated progressive muscle cell swelling over time, with damage transitioning from reversible to irreversible and culminating in necrosis. CONCLUSION: In a rabbit ACS model, ICP was strongly positively correlated with muscle elasticity modulus/SWV. Consequently, 2D-SWE may represent a novel tool for assessing early-phase ACS.

Comparison of 2D Shear Wave Elastography and Transient Elastography in Non-Invasive Evaluation of Liver Fibrosis in Hepatitis C Virus-Related Chronic Liver Disease.

Background: Transient Elastography (TE) is widely regarded as the most reliable non-invasive method for evaluating liver fibrosis. Recently, new techniques such as 2D Shear Wave Elastography (2D-SWE) have been developed. This study aimed to evaluate the correlation between TE and 2D-SWE in patients with HCV-related chronic liver disease and to redefine the cut-off values of 2D-SWE for predicting different stages of fibrosis based on our results. Methods: Both TE (Fibroscan, Echosens, Paris, France) and 2D-SWE (SuperSonic Imagine) were performed simultaneously in 170 patients, including those with active and eradicated HCV infection. Spearman's rank correlation coefficient was used to assess the correlation between the two measurements, and the concordance between the assigned METAVIR classes was calculated using Cohen's kappa coefficient. ROC curves were constructed to determine the optimal cut-off values for 2D-SWE. Results: Ten patients were excluded for invalid measurements. In the remaining 160 patients, TE and 2D-SWE demonstrated a high correlation (ρ = 0.83, p < 0.0001) and good agreement in METAVIR classification (k = 0.74). The optimal cut-off values identified for 2D-SWE were as follows: ≥ 7 kPa for F ≥ 2, ≥ 8.3 kPa for F ≥ 3, and ≥ 9.4 kPa for F4. Conclusions: 2D-SWE is a viable alternative to TE for patients with HCV-related chronic liver disease. Our data suggest that the currently accepted 2D-SWE cut-off values for cirrhosis (F4) should be reconsidered and potentially lowered.

Associations Between Multiparametric US-Based Indicators and Pathological Status in Patients with Metabolic Associated Fatty Liver Disease.

OBJECTIVE: Noninvasive evaluation of metabolic dysfunction-associated fatty liver disease (MAFLD) using ultrasonography holds significant clinical value. The associations between ultrasound (US)-based parameters and the pathological spectra remain unclear and controversial. This study aims to investigate the associations thoroughly. METHODS: The participants with MAFLD undergoing liver biopsy and multiparametric ultrasonography were prospectively recruited from December 2020 to September 2022. Three US-based parameters, namely attenuation coefficient (AC), liver stiffness (LS) and dispersion slope (DS) were obtained. The relationship between these parameters and steatosis grades, inflammation grades and fibrosis stages was examined. RESULTS: In this study with 116 participants, AC values significantly differed across distinct steatosis grades (p < 0.001), while DS and LS values varied among inflammation grades (p < 0.001) and fibrosis stages (p < 0.001). The area under the receiver operating characteristic curves (AUCs) of AC ranged from 0.82 to 0.84 for differentiating steatosis grades, while AUCs of LS ranged from 0.62 to 0.76 for distinguishing inflammation grades and 0.83-0.95 for discerning fibrosis stages. AUCs for DS ranged from 0.79 to 0.81 in discriminating inflammation grades and 0.80-0.88 for differentiating fibrosis stages. Subgroup analysis revealed that LS demonstrated different trends in inflammation grade but consistent trends in fibrosis stage across subgroups, whereas DS showed consistent trends for both inflammation grade and fibrosis stage across all subgroups. CONCLUSION: AC values indicate the degree of hepatic steatosis but not inflammation or fibrosis. LS values are determined only by fibrosis stage and are not associated with inflammation grades. DS values are associated with both fibrosis and inflammation grades.

Protocol for acquisition of images and measurement of transabdominal ultrasound pancreatic two-dimensional shear wave elastography (2D-SWE). / Protocolo de adquisición de imágenes y medición de la elasticidad pancreática mediante elastografía por onda de cizallamiento bidimensional (2D-SWE) transabdominal.

INTRODUCTION: Transabdominal ultrasound (TU) pancreatic 2D-SWE elastography is a developing technique that needs to be protocolized. OBJECTIVES: Establish a protocol for image acquisition and measurement of TU pancreatic - 2D-SWE elastography and estimate the minimum number of measurements to be performed. MATERIALS AND METHODS: Ten measurements of pancreatic elasticity were taken in healthy volunteers using TU-2D-SWE, following a strict protocol for image acquisition and measurement. RESULTS: The 70% of the participants were women, with an average age, weight, and BMI of 49.5±15.7 years, 65.9±11.9kg, and 24.5±4.2kg/m2, respectively. Measurements were taken from the body (70%), tail (16.7%), and pancreatic head (13.3%). The median mean velocity and elasticity were 1.46±0.25cm/sec and 6.46±2.87KPa, respectively. The ROI depth was 4.12±1cm and the SP-ROI distance was 5.2mm on average. There were no statistically significant differences between the 10 measurements. The reliability analysis of the measurements showed high internal consistency and repeatability. Taking 5-6 measurements ensured high concordance with the ten reference measurements. The measurements were significantly lower when the SP-ROI values were intermediate (0.3-0.6cm). The measurement accuracy was higher when performed at a depth less than 4.8cm. CONCLUSION: To measure pancreatic elasticity using TU-2D-SWE, we propose a strict protocol for image acquisition and measurement, taking a minimum of 5 measurements in the best visualized and accessible pancreatic portion, and preferably at a depth of less than 4.8cm.

Cardiac 2-D Shear Wave Imaging Using a New Dedicated Clinical Ultrasound System: A Phantom Study.

OBJECTIVE: The purpose of this study was to assess cardiac shear wave imaging implemented in a new MACH 30 ultrasound machine (SuperSonic Imaging, Aix-en-Provence, France) and interfaced with a linear probe and a phased array probe, in comparison with a previously validated Aixplorer system connected to a linear probe (SuperSonic Imaging) using Elasticity QA phantoms (Models 039 and 049, CIRS Inc., Norfolk, VA, USA). METHODS: Quantile-quantile plots were used for distribution agreement. The accuracy of stiffness measurement was assessed by the percentage error and the mean percentage error (MPE), and its homogeneity, by the standard deviation of the MPE. A p value <0.01 was considered to indicate statistical significance. RESULTS: The accuracy of dedicated cardiac sequences for linear probes was similar for the two systems with an MPE of 8 ± 14% versus 20 ± 21% (p = not significant) with the SuperSonic MACH 30 and Aixplorer, respectively, and was influenced by target stiffness and location of the measurement in the field of view, but without drift over time. The optimal transthoracic cardiac probe workspace was located between 4 and 10 cm, with an MPE of 29.5 ± 25% compared with 93.3 ± 130% outside this area (p < 0.0001). In this area, stiffness below 20 kPa was significantly different from the reference (p < 0.0001). The sectorial probe revealed no MPE difference in any of the measurement areas, with no significant lateral or axial gradient. CONCLUSION: The new Supersonic MACH 30 system upgraded with a sectorial probe and specific cardiac settings provided homogenous stiffness measurements, especially when operating at depths between 4 and 10 cm. These phantom results may be useful in designing future in vivo studies.

Liver Investigation: Testing Marker Utility in Steatohepatitis (LITMUS): Assessment & validation of imaging modality performance across the NAFLD spectrum in a prospectively recruited cohort study (the LITMUS imaging study): Study protocol.

Non-alcoholic fatty liver disease (NAFLD) is the liver manifestation of the metabolic syndrome with global prevalence reaching epidemic levels. Despite the high disease burden in the population only a small proportion of those with NAFLD will develop progressive liver disease, for which there is currently no approved pharmacotherapy. Identifying those who are at risk of progressive NAFLD currently requires a liver biopsy which is problematic. Firstly, liver biopsy is invasive and therefore not appropriate for use in a condition like NAFLD that affects a large proportion of the population. Secondly, biopsy is limited by sampling and observer dependent variability which can lead to misclassification of disease severity. Non-invasive biomarkers are therefore needed to replace liver biopsy in the assessment of NAFLD. Our study addresses this unmet need. The LITMUS Imaging Study is a prospectively recruited multi-centre cohort study evaluating magnetic resonance imaging and elastography, and ultrasound elastography against liver histology as the reference standard. Imaging biomarkers and biopsy are acquired within a 100-day window. The study employs standardised processes for imaging data collection and analysis as well as a real time central monitoring and quality control process for all the data submitted for analysis. It is anticipated that the high-quality data generated from this study will underpin changes in clinical practice for the benefit of people with NAFLD. Study Registration: clinicaltrials.gov: NCT05479721.

Value of Multimodal Data From Clinical and Sonographic Parameters in Predicting Recurrence of Hepatocellular Carcinoma After Curative Treatment.

OBJECTIVE: The objective of the work described here was to assess the value of the combination of pre-operative multimodal data-including clinical data, contrast-enhanced ultrasound (CEUS) information and liver stiffness measurement (LSM) based on 2-D shear wave elastography (SWE)-in predicting early (within 1 y) and late (after 1 y) recurrence of hepatocellular carcinoma (HCC) after curative treatment. METHODS: We retrospectively included 101 patients with HCC who met the Milan criteria and received curative treatment. The multimodel data from clinical parameters, LSM by 2-D SWE and CEUS enhancement patterns were collected. The association between different variables in HCC recurrence was accessed using a Cox proportional hazard model. On the basis of the independent factors of early recurrence, models with different source variables were established (Clinical Model, CEUS-Clinical Model, SWE-Clinical Model, CEUS-SWE-Clinical Model). The goodness-of-fit of models was evaluated and the performance trends of different models were calculated by time-dependent area under the curve (AUC). RESULTS: Two-dimensional SWE, CEUS enhancement patterns and clinical parameters (spleen length, multiple tumors, α-fetoprotein, albumin and prothrombin time) were independently associated with early recurrence (all p values <0.05). Multiple tumors and a decrease in albumin independently contributed to the late recurrence. The model fit of CEUS-SWE-Clinical Model was superior to other models in predicting early recurrence (all p values <0.05). The AUCs of the CEUS-Clinical Model were higher from 2 mo to 7 mo, while the SWE-Clinical Model had higher AUCs from 9 mo to 12 mo. CONCLUSION: CEUS enhancement patterns and 2-D SWE were independent predictors of HCC early recurrence as the two factors contributed to the predictive performance at different times. The multimodal model, which included diverse data in predicting early HCC recurrence, had the best goodness-of-fit.

Intra-individual comparison of two-dimensional shear wave elastography techniques using plane wave imaging and the multi-beam technique: are they interchangeable in measuring liver fibrosis?

PURPOSE: This study compared two different two-dimensional shear wave elastography techniques-plane wave imaging (PWI) and multi-beam (MB) imaging-from the same vendor to evaluate liver fibrosis. METHODS: In this prospective study, 42 patients with chronic liver disease who had recently undergone magnetic resonance elastography (<3 months) were enrolled, and their liver stiffness (LS) values were measured using PWI or MB. The LS values (kPa) were compared using the Wilcoxon rank-sum test. Inter-technique reproducibility and intra-observer repeatability were assessed using Bland-Altman analysis with 95% limits of agreement (LOA) and coefficients of variation (CVs). The cutoff values for predicting severe fibrosis (≥F3) were estimated using receiver operating characteristic curve (ROC) analysis, with magnetic resonance elastography as the reference standard. RESULTS: PWI exhibited technical failure in four patients. Therefore, 38 patients underwent both examinations. The LS values showed moderate agreement between PWI and MB (CV, 22.5%) and 95% LOA of -3.71 to 7.44 kPa. The MB technique showed good intra-observer agreement (CV, 8.1%), while PWI showed moderate agreement (CV, 11.0%). The cutoff values of PWI and MB for diagnosing ≥F3 were 12.3 kPa and 13.8 kPa, respectively, with areas under the ROC curve of 0.89 and 0.95 (sensitivity, 100% and 100%; specificity, 65.6% and 85.7%). CONCLUSION: The LS values significantly differed between PWI and MB, hindering their interchangeable use in longitudinal follow-up. Considering its low technical failure rate and better repeatability, the MB technique may be preferable for evaluating liver fibrosis in chronic liver disease patients.

A methodological study of 2D shear wave elastography for noninvasive quantitative assessment of renal fibrosis in patients with chronic kidney disease.

PURPOSE: To determine the optimal measurement method of 2D shear wave elastography (2D-SWE) for noninvasive quantitative assessment of renal fibrosis in chronic kidney disease (CKD) patients. METHODS: A total of 190 CKD patients were enrolled for 2D-SWE of right kidney. The success rates, coefficients of variation (CV), and pathological correlation of different measurement sites, body positions, and depths were compared. RESULTS: (1) Measurement sites: Success rate in the middle part (100%) was higher than that in the lower pole (97.3%, P > 0.05). CV in the middle part (10.2%) was lower than that in the lower pole (16.4%, P < 0.05). Pathological correlation of the middle part (r = - 0.452, P < 0.05) was higher than that of the lower pole (r = 0.097, P > 0.05). (2) Body positions: Success rate in left lateral decubitus position (100%) was higher than that in supine (99.4%, P > 0.05) and prone position (99.4%, P > 0.05). CV was lowest (11.9%) and pathological correlation was highest (r = -0.256, P < 0.05) in prone position. (3) Measurement depths: Success rate at depth < 4 cm (100%) was higher than that at depth ≥ 4 cm (98.8%, P > 0.05). CV at depth < 4 cm (11.1%) was lower than that at depth ≥ 4 cm (14.4%, P < 0.05). Pathological correlation at depth < 4 cm (r = - 0.303, P < 0.05) was higher than that at depth ≥ 4 cm (r = - 0.156, P > 0.05). CONCLUSION: The optimal measurement method of 2D-SWE for renal fibrosis assessment was prone position, renal middle part, and measurement depth < 4 cm.

Application and Diagnostic Performance of Two-Dimensional Shear Wave Elastography and Liver Fibrosis Scores in Adults with Class 3 Obesity.

There are no ideal non-invasive tests for assessing the severity of liver fibrosis in people with metabolic dysfunction-associated steatotic liver disease (MASLD) and class 3 obesity, where body habitus often makes imaging technically challenging. This study aimed to assess the applicability and diagnostic performance of two-dimensional shear wave elastography (2D-SWE), alongside several serum-based liver fibrosis scoring methods, in individuals with class 3 obesity. A cross-sectional study was conducted in patients aged ≥18 years and with a body mass index (BMI) ≥ 40 kg/m2 who were participants in a publicly funded multidisciplinary weight management program in South Western Sydney. The 2D-SWE was performed using the ElastQ Imaging (EQI) procedure with the Phillips EPIQ Elite series ultrasound. An EQI Median value of ≥6.43 kPa was taken as a cutoff score for significant fibrosis, and the scan was considered valid when the liver EQI IQR/Med value was <30%. The Fibrosis-4 (FIB-4) index, AST-to-platelet ratio index (APRI), NAFLD fibrosis score (NFS), and circulating fibroblast activation protein index (FAP index) were calculated from fasting blood samples. The participants (n = 116; 67.2% female) were aged 47.2 ± 12.9 years, with BMI 54.5 ± 11.0 kg/m2. EQI Median values were obtained for 97.4% (113/116) of the 2D-SWE scans, and 91.4% (106/116) of the scans were considered valid. The EQI Median values exhibited a moderately positive correlation with the FIB-4 index (r = 0.438; p < 0.001) and a weakly positive correlation with the APRI (r = 0.388; p < 0.001), NFS (r = 0.210; p = 0.036) and FAP index (r = 0.226; p = 0.020). All liver fibrosis scores were positively correlated with one another. Among those referred for a liver biopsy based on the 2D-SWE and serum scores, half (11/22) underwent liver biopsy, and their 2D-SWE scores exhibited 72.7% accuracy (sensitivity: 71.4%; specificity: 75%) in detecting significant fibrosis. Our results show that 2D-SWE is a feasible, non-invasive test to assess liver fibrosis among people with class 3 obesity. Further research is needed to assess how 2D-SWE can be used alongside existing serum-based risk scores to reliably detect significant fibrosis, which would potentially reduce the need for invasive liver biopsy.

Noninvasive Prediction of Advanced Fibrosis in Pediatric Liver Disease-Discriminatory Performance of 2D Shear Wave Elastography, Transient Elastography and Magnetic Resonance Elastography in Comparison to Histopathology.

Background: Elastography can be measured with different imaging techniques and is increasingly used for noninvasive assessment of hepatic fibrosis. Little is known about the performance, and interrelation of different elastographic techniques, in prediction of hepatic fibrosis in pediatric liver disease. Objectives: We aimed to determine the discriminatory value for advanced fibrosis (Metavir F3-4) and evaluate the applicability of 2D shear wave ultrasound elastography (USe), Transient Elastography (TE) and Magnetic Resonance elastography (MRe) in pediatric liver disease. Methods: In patients with pediatric liver disease aged 0−19 years, USe, TE and MRe were compared with histopathological fibrosis stage. Multivariate logistic regression models for advanced fibrosis were considered. Discriminative performance was assessed by the area under the receiver operating characteristic curve and the Brier Score. Primary analyses included complete cases. Multiple imputation was used as sensitivity analysis. Results: In 93 histologically evaluated patients USe, TE and MRe were performed 89, 93 and 61 times respectively. With increased liver stiffness values, significantly increased odds for presenting F3-4 were seen in individual models for ALT < 470 U/L, whereas the effect for ALT > 470 U/L was non-significant. Area under the curve and Brier Score for discrimination of advanced fibrosis were 0.798 (0.661−0.935) and 0.115 (0.064−0.166); 0.862 (0.758−0.966) and 0.118 (0.065−0.171); 0.896 (0.798−0.994) and 0.098 (0.049−0.148) for USe, TE and MRe respectively. No significant increase in discriminatory ability was found when combining elastographic modalities. Conclusions: In pediatric liver disease, USe, TE and MRe had a good discriminatory ability for assessment of advanced liver fibrosis, although TE and MRe performed best. In most children with pediatric liver disease, TE is a reliable and easily applicable measure.

2D shear wave elastography in evaluation of prognostic factors in breast cancer.

PURPOSE: To evaluate the reproducibility of the 2D shear wave elastography (2D-SWE) method and to identify the prognostic factors of breast lesions. METHODS: In this prospective study, 44 female patients were consecutively included from January 2020 to September 2021. All patients showing visible masses at B-mode ultrasound underwent to clinical evaluation, followed by qualitative and quantitative 2D-SWE by two different operators with over 15-year and 2-year experience, respectively. Subsequently, patients underwent to surgical treatment after core needle biopsy. Reproducibility of qualitative and quantitative 2D-SWE was evaluated by Cohen's kappa and intraclass correlation coefficient (ICC). Clinical, imaging, and histopathological data and 2D-SWE evaluations were analysed with Spearman's rank correlation test. RESULTS: The mean age of the patients was 55 years ± 12. The mean histological and ultrasound tumour size of were 23.1 mm ± 13.2 and 17.2 mm ± 10.2, respectively. The interobserver agreement showed a good reproducibility limited to the qualitative evaluation colour maps (Cohen's kappa = 0.603) and to the quantitative evaluation E ratio (ICC = 0.771). Correlation analysis between the ultrasound and 2D-SWE values and the clinical-pathological parameters showed a significant relationship between E ratio and Elston-Ellis grading (P < 0.030) and between tumour size and Elston-Ellis grading (P < 0.041). CONCLUSION: The 2D-SWE has shown good reproducibility among operators with different experience. It could be a promising tool in the evaluation of some prognostic factors in ultrasound visible breast cancer.

Risk Predictors of Advanced Fibrosis in Non-Alcoholic Fatty Liver Disease.

The assessment of fibrosis in chronic liver diseases using non-invasive methods is an important topic in hepatology. The aim of this study is to identify patients with non-alcoholic fatty liver disease (NAFLD) and advanced liver fibrosis by establishing correlations between biological/ultrasound markers and non-invasively measured liver stiffness. This study enrolled 116 patients with non-alcoholic fatty liver disease, which were evaluated clinically, biologically, and by ultrasound. Liver fibrosis was quantified by measuring liver stiffness by shear wave elastography (SWE). Multiple correlation analysis of predictors of liver fibrosis identified a number of clinical, biological, and ultrasound parameters (BMI, blood glucose, albumin, platelet count, portal vein diameter, bipolar spleen diameter) that are associated with advanced liver fibrosis in patients with non-alcoholic fatty liver disease. The correlations between the degree of liver fibrosis and the risk values of some serological and ultrasound markers obtained in our study could be useful in clinical practice for the identification of advanced fibrosis in patients with NAFLD.

Comparison Between Different Manufacturers' 2-D and Point Shear Wave Elastography Techniques in Staging Liver Fibrosis in Chronic Liver Disease Using Liver Biopsy as the Reference Standard: A Prospective Study.

The purpose of this study was to assess the utility of 2-D shear wave elastography (SWE) in assessing liver fibrosis in patients with chronic liver disease by comparing its performance with that of point shear wave elastography (pSWE) using liver histological staging as the reference standard. In this ethics committee-approved, single-institution prospective study, pSWE and 2-D SWE velocity measurements were obtained in 121 adult patients (age: 18-70 y, median: 45 y) immediately before a liver biopsy for chronic liver disease. Shear wave velocity (SWV) and Ishak scores were compared using the Kruskal-Wallis test, Spearman's correlation and receiver operating characteristic (ROC) curve analysis. Youden's index was used to determine the optimal cutoff point. There was no technical failure using pSWE and 2-D SWE. The mean difference for SWV between pSWE and 2-D SWE was 0.0223 (limits of agreement: -1.1009, 1.1145). Values for both pSWE and 2-D SWE were significantly correlated with fibrosis stage (Spearman's ρ = 0.606, p < 0.0001; ρ = 0.722, p < 0.001 respectively). The area under the ROC curve differentiating F ≥3 was 0.855 (95% confidence interval: 0.778-0.932) for pSWE and 0.884 (95% CI: 0.817-0.951) for 2-D SWE. The AUC for differentiating F ≥5 was 0.890 (95% CI: 0.826-0.954) for pSWE and 0.926 (95% CI: 0.88-0.973) for 2-D SWE. This study indicates that 2-D SWE provides feasible and accurate assessment of liver fibrosis, comparable to that provided by pSWE from two different manufacturers' machines.

2D Shear Wave Elastography, a promising screening tool for Cystic Fibrosis liver disease, shows a correlation between vitamin D and liver stiffness.

BACKGROUND: Liver disease in Cystic Fibrosis (CFLD) is an early complication of CF. Evidence of CFLD is often subclinical and screening is recommended. Screening includes a biochemical work-up and an ultrasound investigation. Non-invasive methods measuring liver stiffness such as shear wave elastography could be beneficial. This study describes the use of 2D Shear Wave Elastography (2D SWE) in screening for CFLD in a clinical setting and explores its correlation to other indicators of CFLD. Furthermore, a relationship between liver stiffness and nutritional status, lung function and glucose tolerance was explored. MATERIAL AND METHODS: A retrospective cohort study was performed at a pediatric CF center. Information was gathered from the patients' charts and the Swedish national CF registry. The patients included had been evaluated for the presence of CFLD by ultrasound and 2D SWE during 2018-2020. Demographic data as well as data concerning nutritional status, lung function and glucose tolerance were collected. RESULTS: Fifty-one subjects were included with a median age of 11 years. Four children who had biopsy confirmed liver cirrhosis had significantly increased liver stiffness. There was a statistically significant negative correlation between liver stiffness and vitamin D levels and FEV1% predicted respectively. Children with abnormal glucose tolerance had increased liver stiffness compared to their normal glucose tolerant counterparts. CONCLUSION: Measuring liver stiffness by 2D SWE is a reliable addition to CFLD screening with data comparable to the more conventional ultrasound investigation. Increased liver stiffness is associated with lower vitamin D levels, lower FEV1% predicted and abnormal glucose tolerance.

Liver Stiffness Measurements by 2D Shear-Wave Elastography: Effect of Steatosis on Fibrosis Evaluation.

BACKGROUND. Hepatic steatosis has been found not to affect liver stiffness measurements (LSM) from MR elastography (MRE). However, the effect of steatosis on LSM from 2D shear-wave elastography (SWE) remains controversial. OBJECTIVE. The purpose of this study was to evaluate the effect of hepatic steatosis on the diagnostic performance of LSM from 2D SWE (LSM2D SWE) for evaluation of liver fibrosis with LSM from MRE (LSMMRE) as the reference standard. METHODS. This retrospective study included 888 patients (442 women, 446 men; median age, 67 years) with chronic liver disease who underwent LSM by both 2D SWE and MRE within a 3-month window. Steatosis was also assessed on ultrasound examinations by ultrasound-guided attenuation parameter (UGAP) and on MRI examinations by proton density fat fraction (PDFF). Fibrosis stages and steatosis grades were classified according to previously established thresholds. The effect of steatosis on LSM2D SWE was evaluated by Kruskal-Wallis tests with post hoc tests and ROC analysis. RESULTS. LSM2D SWE were significantly higher in patients with severe steatosis than those without steatosis by MRI PDFF among patients with F0 fibrosis (5.5 kPa [IQR, 4.7-6.0 kPa] vs 4.7 kPa [IQR, 4.2-5.5 kPa], p = .009) and F1 fibrosis (6.3 kPa [IQR, 6.0-7.2 kPa] vs 5.9 kPa [IQR, 5.0-6.6 kPa], p = .009). LSM2D SWE were significantly higher in patients with severe steatosis than those without steatosis by UGAP among patients with F1 fibrosis (6.6 kPa [IQR, 5.9-7.3 kPa] vs 5.9 kPa [IQR, 5.1-6.5 kPa], p = .008). Otherwise, LSM2D SWE did not vary significantly across steatosis grades at a given fibrosis stage (all p > .05). Sensitivity and specificity for ≥ F1 fibrosis were 63.8% and 91.5% in patients without versus 60.4% and 80.9% in patients with severe steatosis by MRI PDFF and were 62.4% and 91.5% in patients without versus 72.1% and 78.3% in patients with severe steatosis by UGAP. CONCLUSION. Severe hepatic steatosis may result in overestimation of LSM2D SWE in patients without or with mild steatosis, reducing the specificity of liver fibrosis detection. CLINICAL IMPACT. Assessment of UGAP at 2D SWE may help identify patients in whom LSM2D SWE should be assessed with caution. In patients with no or mild steatosis by 2D SWE and severe steatosis by UGAP, MRE helps provide a more reliable measure of liver fibrosis.

Diagnostic performance of 2D-shear wave elastography and serum fibrosis markers for evaluation of hepatic graft fibrosis in pediatric liver-inclusive transplant recipients: A prospective pilot study.

BACKGROUND: Liver biopsy is the gold standard for hepatic fibrosis staging, but it is invasive and has potential severe complications. We aimed to determine the diagnostic performance of 2D-SWE and serum markers to predict significant hepatic graft fibrosis (≥F2) in pediatric liver-inclusive transplant recipients. METHODS: This prospective, cross-sectional pilot study included children younger than 19 years who had received a LT or LSBT and underwent a liver biopsy performed for clinical indications. LS was measured using 2D-SWE. The AUROC was calculated to evaluate the diagnostic performance of 2D-SWE and biomarkers (AST/ALT ratio, APRI, FIB4) for predicting significant fibrosis. RESULTS: Twenty-two children (13 males, 8 LSBT) were included. Eighteen (81.8%) children received a whole liver graft. Thirteen (59.1%) patients had hepatic fibrosis (≥F1) and four (18.2%) had significant fibrosis. The AUROCs of AST/ALT ratio, APRI, and FIB4 for predicting significant hepatic graft fibrosis were 0.71 (p = .29), 0.85 (p = .0001), and 0.76 (p = .03), respectively. When FIB4 was calculated using the hepatic graft's age, its AUROC improved to 0.85 (p < .0001). The AUROC of 2D-SWE for predicting significant hepatic graft fibrosis was 0.80 (p = .046). When 2D-SWE was combined with APRI or FIB4, its AUROC improved to 0.82 (p = .08) and 0.87 (p = .002), respectively. CONCLUSIONS: APRI and FIB4 can accurately predict significant hepatic graft fibrosis. 2D-SWE may serve as a valuable adjunct tool to detect significant graft fibrosis, especially when combined with these serum markers.

An exploratory study of two-dimensional shear-wave elastography in the diagnosis of acute compartment syndrome.

BACKGROUND: Two-dimensional shear-wave elastography (2D-SWE) is an ultrasound elastography technique that uses shear waves to quantitatively measure tissue stiffness and it has recently been developed as a safe, real-time, and noninvasive imaging technique. The purpose of this study was to investigate the value of 2D-SWE in the diagnosis and treatment of acute compartment syndrome (ACS). METHODS: 2D-SWE was used to measure the elasticity values of the main muscles in the superficial compartments of the calf in 212 healthy volunteers, and the difference in the muscle elasticity values between different gender and age groups were analyzed. Nine patients with clinical suspicion of ACS were included in this study and 2D-SWE was used to measure the elasticity values of the muscles on the affected and unaffected sides, and a comparative analysis was performed. RESULTS: The mean elasticity values of the tibialis anterior (TA), peroneus longus (PL), and gastrocnemius medialis (GA) muscles in the relaxed state of the 212 healthy volunteers were 25.4 ± 3.2 kPa, 15.7 ± 1.5 kPa, and 12.1 ± 2.1 kPa, respectively. No statistically significant differences was observed in the elasticity values of the same muscle under the state of relaxation in different gender and age groups (p > 0.05). A statistically significant difference in the elasticity values of the muscle between the affected and unaffected sides in the fasciotomy group (p < 0.05, n = 5) was observed. In contrast, no difference in the elasticity values of the muscle between the affected and unaffected sides in the conservative group (p > 0.05, n = 4) was observed. There was a statistically significant difference in the elasticity values of the muscle on the affected side in the two treatment groups (p < 0.05). CONCLUSIONS: When the ACS occurs, the muscle elasticity of the affected limb increases significantly. 2D-SWE is expected to be a new noninvasive technique for the assessment of ACS and may provide a potential basis for clinical diagnosis and treatment.

Comparative Utility of Transient and 2D Shear Wave Elastography for the Assessment of Liver Fibrosis in Clinical Practice.

The aim of the study was to investigate the feasibility and correlation of liver stiffness measurements (LSM) between 2D-shear wave elastography (2D-SWE) and transient elastography (TE) in patients with chronic liver disease. Over 4 months, 421 patients with chronic liver disease of any cause underwent LSM by 2D-SWE and TE (M and/or XL probe) and controlled attenuation parameter at the same visit. LSM was not feasible by TE in 16 (3.8%) and by 2D-SWE in 17 (4.0%) patients. Median LSM were 8.9 and 8.7 kPa with TE and 2D-SWE, respectively, having a strong correlation (r = 0.774, p < 0.001) in the total cohort and in any cause of liver disease (r = 0.747-0.806, p < 0.001). There was a strong agreement on diagnosis of severe fibrosis (k-statistic: 0.841, p < 0.001) or cirrhosis (k-statistic: 0.823, p < 0.001). Both methods had increased failure rates in patients with obesity and/or increased waist circumference. Among 104 obese patients, TE was more feasible than 2D-SWE (92.3% vs 85.6%, p < 0.001]. LSM by 2D-SWE are strongly correlated to LSM by TE independently of the etiology of chronic liver disease, stage of fibrosis, degree of liver steatosis, and patients' characteristics. TE with the XL probe may be superior in a minority of obese patients.

Liver stiffness measurements by 2-dimensional shear wave elastography compared to histological and ultrasound parameters in primary biliary cholangitis.

BACKGROUND AND AIMS: Liver stiffness measurements (LSMs) by 2-dimensional-shear-wave elastography (LSM2D-SWE) are now widely used in hepatology. However, relevant information for primary biliary cholangitis (PBC) is scant. We compare LSM2D-SWE with liver biopsy (LB) in a cohort of PBC patients in Greece. METHODS: Data of 68 LBs from 53 PBC patients were retrospectively analyzed and fibrosis stage was compared to LSM2D-SWE. Forty-six patients (86.8%) were females and at the time of LBx median (IQR) age was 62.6 (53.2-72.1). Demographic, UDCA treatment, histological and B-mode ultrasound data were tested for their influence on LSM2D-SWE estimates. RESULTS: Liver fibrosis stages F0-F4 were found in 4, 19, 19, 16 and 10 cases, respectively. Across stages F0-F4, the LSM2D-SWE was 5.6 (5.1-6.1), 7.0 (5.8-7.7), 9.1 (7.3-11.5), 10.8 (9.9-12.2) and 14.5 (11.9-25.7) kPa, respectively, with highly significant difference (p<.001). The LSM2D-SWE differed also significantly between F0 vs. F1 (p=.027), F1 vs. F2 (p=.005) and F3 vs. F4 (p=.017). The discriminatory ability of LSM2D-SWE for mild, significant, severe fibrosis and cirrhosis was highly significant in all comparisons (p<.001), with AUC2D-SWE 95.3%, 87.4%, 85.3% and 95.3% and accuracy 89.7%, 85.3%, 80.9% and 86.8%, respectively. Among 21 parameters tested, significant predictors of LSM2D-SWE by multiple linear regression were fibrosis stage, portal inflammation and parenchymal heterogeneity. The portal inflammation grade accounted for 32.2% of LSM variation with adjusted R2 0.428. CONCLUSIONS: In patients with PBC, LSM measurements by 2D-SWE can reliably discriminate between mild, significant, severe fibrosis and cirrhosis. Measurements are significantly affected by portal inflammation grade.