2D SWE Research Articles

Feasibility of liver stiffness measured using two-dimensional shear wave elastography in assessing preoperative liver function for patients with hepatocellular carcinoma.

To evaluate the feasibility of liver stiffness (LS) measured using two-dimensional shear wave elastography (2D SWE) in assessing preoperative liver function for patients with hepatocellular carcinoma (HCC). A total of 143 patients who underwent surgical resection for HCC between August 2018 and December 2019 were enrolled prospectively. LS measurement, liver function tests including serum biochemical indicators, and indocyanine green (ICG) clearance test were performed preoperatively. Child-Pugh (CP) score, Albumin-bilirubin (ALBI) score and Model for End-Stage Liver Disease score were calculated. ICG retention rate at 15min (ICG R15) and ICG elimination rate constant (ICG K) were determined automatically. Fibrosis stage was determined based on pathological findings. The association between LS and serum biochemical indicators, liver function scores, and the ICG results were analyzed. Weak to moderate correlations were identified between LS and biochemical indicators of liver function (all p < 0.01). Weak correlation was identified between LS and CP score, and between LS and ALBI score (all p < 0.001). Moderate correlation was identified between LS and ICG R15 (Pearson r = 0.62, p < 0.001), and between LS and ICG K value (Pearson r = - 0.49, p < 0.001). The best cutoff of LS to discriminate a normal ICG R15 was 10.6kPa, with area under the curve (AUC), sensitivity, specificity of 0.874, 0.900 and 0.724, respectively. LS determined using 2D SWE could be a potential tool for the preoperative evaluation of liver function in patients with HCC.

Can ultrasound elastography assess liver quality in brain-dead donors and predict early allograft dysfunction after transplantation?

To evaluate the role of two-dimensional shear wave elastography (2D SWE) in assessing graft quality before liver transplantation and the relationship between donor liver stiffness (LS) and early allograft dysfunction (EAD) after transplantation. Eighty-three donors from January 2018 to December 2018 were involved in this prospective study. Liver stiffness measurements (LSMs) were performed using 2D SWE. The differences in LS values between discarded and transplanted grafts were analyzed. The relationship of donor LS with recipient EAD was also evaluated. Our results suggest that the donor LS values were higher in discarded grafts than in transplanted grafts (24.0 ± 10.9 kPa vs 10.0 ± 2.6 kPa, p < 0.001). LSM failed in one donor. According to multivariate logistic regression analysis, the donor LS values ≥10.9 kPa (odds ratio [OR] 4.042, 95% confidence interval [CI] 1.133-14.421, p = 0.031), BMI (OR 1.287, 95% CI 1.025-1.616, p = 0.030) and INR (OR 6.703, 95% CI 1.338-33.589, p = 0.021) were independently associated with EAD. Donor LSM conducted by 2D SWE might represent an effective quantitative method to evaluate graft quality. Donor LS might predict recipient EAD after liver transplantation.

Effect of Q‐Box size on liver stiffness measurement by two‐dimensional shear wave elastography

To investigate the effect of the Q-Box size on liver stiffness (LS) measurement by two-dimensional shear wave elastography (2D SWE). Ninety-eight patients with chronic liver disease were enrolled. Each patient was continuously measured five times. The Q-Box diameter was adjusted to 10, 20, and 30 mm each time. The liver stiffness values (LSVs) at different diameters were compared in the following groups: LSVs ≤6.2kPa, 6.2kPa < LSVs ≤11 kPa, LSVs >11 kPa. The reliability and repeatability of LS measurement at different diameters were evaluated. The differences in LSVs at different Q-Box diameters were statistically significant only when LSV ≤6.2kPa (p=0.004). There were no statistically significant differences in standard deviation (SD), SD/median, coefficient of variation (CV), and interquartile range (IQR)/median at different Q-Box diameters (p > 0.05). There were statistical differences in minimum LSVs and percentage of minimum LSVs ≤0.2kPa as well as in stability index (SI) and percentage of SI <90% at different Q-Box diameters (p < 0.05). The intraclass correlation coefficients (ICCs) were up to 0.98 at Q-Box diameters of 10, 20, and 30 mm. Our study showed that Q-Box size may lead to significant differences in LSVs, especially when LSVs ≤6.2kPa. The Q-Box size had a large effect on the reliability of a single LS measurement but did not affect the repeatability of multiple measurements.

Liver Stiffness Measured by Two-Dimensional Shear Wave Elastography for Predicting Symptomatic Post-hepatectomy Liver Failure in Patients with Hepatocellular Carcinoma.

To evaluate the ability of liver stiffness (LS) measured by two-dimensional shear wave elastography (2D SWE) to predict symptomatic post-hepatectomy liver failure (SPHLF) in patients with hepatocellular carcinoma (HCC). A total of 119 patients who underwent hepatectomy for HCC between August 2018 and July 2019 were enrolled. Preoperative assessments for LS and other clinicopathological tests were performed in all patients. Univariate and multivariate analyses were conducted for the risk factors of SPHLF. Further subgroup analysis was performed according to multivariate analysis results. SPHLF occurred in 38 patients (31.9%). The best cutoff value of LS for predicting SPHLF was 9.5 kPa. Multivariate analysis identified LS ≥9.5 kPa, greater Child-Turcotte-Pugh (CTP) grade, and major hepatectomy as independent predictors of SPHLF. Based on the extent of hepatectomy, CTP grade could stratify the risk of SPHLF in the minor hepatectomy group (12.2% vs. 100.0%, p = 0.001), whereas LS was superior in predicting SPHLF in the major hepatectomy group (18.9% vs. 72.4%, p < 0.001). In patients with CTP grade A, LS could further stratify the risks of SPHLF in both the minor and major hepatectomy groups (3.7% vs. 22.7%, p = 0.043; 17.6% vs. 70.4%, p < 0.001, respectively). LS measured using 2D SWE could predict SPHLF using the best cutoff value of 9.5 kPa. CTP grade was a stronger indicator of SPHLF in minor hepatectomy, whereas LS was more effective in selecting candidates for major hepatectomy. LS could further stratify the risk of SPHLF in CTP grade A patients, regardless of the extent of hepatectomy.

A 2D SWE meshless model with fictitious water level at dry nodes

In this study, a two-dimensional shallow-water-equation numerical model is developed for simulating free surface water flows with internal moving wet/dry front boundaries. It is based on the Eulerian aspect and meshless approach. The predictor-corrector process is used for the time marching. The spatial derivatives of physical quantities are computed using the local polynomial approximation with the weighted-least-squares approach. A formula for specifying the fictitious water level, which does not exist physically, at dry nodes is proposed. This is the main novelty of the present study and it significantly reduces computation time compared with the authors’ previous work. Four dam break test cases are employed to validate the capability of the present model.

Predictive value of two-dimentional shear wave elastography in posthepatoectomy liver failure

Objective: To investigate the value of two-dimensional shear wave elastography (2D SWE) combined with clinical biochemical data in predicting posthepatoectomy liver failure (PHLF) in patients with hepatocellular carcinoma (HCC). Methods: A total of 274 HCC patients who underwent hepatectomy in Zhongshan Hospital Fudan University from January 2015 to January 2016 were retrospectively collected, including 235 males and 39 females, age 19-80 (56±11) years. All patients were confirmed to be HCC by postoperative pathology. The preoperative 2D SWE examination, laboratory examination results and intraoperative indicators were analyzed. According to the occurrence of PHLF after surgery, single factor analysis and multiple logistic regression analysis were performed on the above indicators to obtain a binary logistic regression model, and evaluate the diagnostic effect of the model on PHLF. In addition, 103 HCC patients from October 2019 to January 2020 were retrospectively collected as an external validation set, including 89 males and 14 females, age 23-80 (55±11) years old. Results: The liver stiffness measurement (LSM) obtained from 2D SWE, INR and Laminin (LN) were independent predictors of PHLF. The formula of prediction model PM=-15.451+0.095×LSM+11.7×INR+0.012×LN was obtained by combining above three factors. The area under the curve (AUC) of PHLF was 0.82, which was higher than that of end-stage liver disease model (MELD) score and Child-Pugh grading diagnosis of PHLF. The AUC of PHLF predicted by PM in the external validation group was 0.81. Conclusion: 2D SWE is helpful for clinicians to evaluate liver reserve function preoperatively and to predict the occurrence of PHLF in patients with HCC.

Methodological Study to Investigate the Potential of Ultrasound-Based Elastography and Texture as Biomarkers to Monitor Liver Tumors.

Aims and objectives: In order to evaluate the responses of hepatic lesions to treatment in terms of tissue stiffness and heterogeneity, this work investigated the robustness of 2D shear-wave elastography (2D SWE) stiffness measurements and texture analyses in vitro and in vivo in terms of repeatability and variability. Methods and materials: A multioperator (n = 5) study was performed with an ultrasonic elastography device on two sets of phantoms. For the first set of phantoms, 10 measurements for each of the eight inclusions were performed by each observer, whereas the second set of phantoms was used to evaluate the influence of depth on the stiffness measurements. Variability of the stiffness measurements was evaluated in vivo on 10 healthy livers, with 10 measurements for each hepatic segment. Texture analyses were performed in B-mode, obtaining elastography images for every hepatic segment. Results: Stiffness measurements were influenced by depth, particularly when exceeding 7 cm. In vivo measurements demonstrated that measurements of segments I, VII, and VIII were less reliable, mainly due to their deeper locations. The protocols used were more flexible in terms of acquisition setup and probe placement than those currently used with Fibroscan®. For texture analysis on the B-mode images, 12 features showed low variability regardless of the evaluated hepatic segment. On elastogram, only two features showed low variability, but not in every segment. Conclusion: We demonstrated the robustness of two methodologies for the quantification of liver stiffness and heterogeneity. Further clinical studies should evaluate whether these techniques can assess tumor responses to treatment and, therefore, have the potential to be used as imaging biomarkers.

2D shear wave elastography combined with age and serum biomarkers prior to kasai surgery predicts native liver survival of biliary atresia infants

The prognosis of patients with biliary atresia (BA) after Kasai portoenterostomy (KPE) varies, and precisely predicting the outcomes of KPE before surgery is still challenging. A total of 158 patients who underwent KPE in our hospital were included in this study. The patients in the training cohort were recruited from January 2012 to October 2017 (n=118), and then, those in the validation cohort were recruited from November 2017 to April 2019 (n=40). Combined nomogram models were developed based on two-dimensional shear wave elastography (2D SWE) values and other biomarkers. The utility of the proposed models was evaluated by C-index. 2D SWE played a potentially important role in predicting native liver survival (NLS) of BA patients with a C-index of 0.69 (0.63 to 0.75) in the training cohort and 0.76 (0.67 to 0.85) in the validation cohort. The nomogram A based on 2D SWE values, age, gamma-glutamyl transferase (GGT) and aspartate aminotransferase-to-platelet ratio (APRI) had a better C-index in the training cohort [0.74 (0.68-0.80) vs. 0.66 (0.60-0.73), P=0.017] and in the validation cohort [0.78 (0.70-0.86) vs. 0.60 (0.49-0.71), P=0.002] than the nomogram B (without 2D SWE). Using risk score developed from nomogram A, we successfully predicted 88.0% (22/25) of patients in the training cohort and 75.0% (9/12) in the validation cohort to have survival time of less than 12months after KPE. The combined nomogram model based on 2D SWE values, age, GGT and APRI prior to KPE can effectively predict NLS in BA infants.

Two-dimensional shear wave elastography for significant liver fibrosis in patients with chronic hepatitis B: A systematic review and meta-analysis

PurposeTo determine the diagnostic performance and cutoff value of two-dimensional shear wave elastography (2D SWE) for detecting significant liver fibrosis in patients with chronic hepatitis B (CHB). MethodsA systematic literature search of the PubMed, EMBASE, Cochrane Library databases and Web of Science was conducted. Bivariate modelling and summary receiver-operating-characteristic (ROC) modelling were constructed to summarize the diagnostic performance of 2D SWE. Meta-regression analyses were performed to explore the source of heterogeneity. ResultsEleven eligible studies with 2623 patients were included. 2D SWE showed a summary sensitivity of 88 % (95 % CI: 83–91), specificity of 83 % (95 % CI: 78–88) and area under the ROC curve of 0.92 (95 % CI: 0.89–0.94) for detecting significant fibrosis in CHB patients. The mean threshold of 2D SWE was 7.91 kPa (range: 6.73–10.00 kPa). Notably, the cutoffs of studies excluding patients with history of prior antiviral therapy were generally lower than that of studies without excluding those who had received antiviral treatment, with an average of 7.15 kPa and 8.87 kPa, respectively (p < 0.01). Meta-regression analysis revealed that enrollment of consecutive patients was the only significant factor influencing heterogeneity (p < 0.01). Specifically, studies recruiting consecutive patients with CHB had significantly lower sensitivity than those with absence of consecutive enrolment (0.83 vs 0.92, p < 0.01). Conclusions2D SWE is an excellent modality for predicting significant liver fibrosis in CHB populations. Further work is required to establish the cutoffs that account for antiviral treatment as a potential confounding factor.

Comparisons and Combined Application of Two-Dimensional and Three-Dimensional Real-time Shear Wave Elastography in Diagnosis of Thyroid Nodules.

Purpose Two-dimensional and three-dimensional real-time shear wave elastography (2D+3D SWE) represents a new technology for the quantification of tissue elasticity. This study investigated whether they could be performed to differentiate between benign and malignant thyroid nodules.Methods Conventional B-mode ultrasound, 2D and 3D SWE were performed in 96 patients with 97 thyroid nodules with pathology results.Results All the elastography values of 2D&3D SWE in malignant thyroid nodules were higher than those in benign nodules. These two elastography methods alone could not improve diagnostic value comparing to B-mode ultrasound significantly. However, B-mode US + 2D SWE (TI-RADS ≥ 4c or S-Emean ≥ 23.75 kPa, suspicious), B-mode US + 3D SWE (TI-RADS ≥ 4c or 3D-T-Emean ≥ 20.75 kPa, suspicious), B-mode US + 2D + 3D SWE (TI-RADS ≥ 4c or S-Emean ≥ 23.75 kPa or 3D-T-Emean ≥ 20.75 kPa, suspicious) had higher sensitivity and accuracy values than those of 3 methods alone but lower specificity values. Among them, B-mode ultrasound + 2D SWE had the highest sensitivity, NPV, accuracy and Youden's index (0.881, 0.788, 0.804 and 0.57).Conclusions 2D SWE or 3D SWE alone could not improve the diagnostic value of differentiating malignant from benign thyroid nodules comparing to conventional B-mode ultrasound. But combination methods could improve the diagnostic value, especially B-mode US + 2D SWE.

Ultrasound Techniques for the Assessment of Liver Stiffness: A Correct Terminology

Potential conflict of interest: Dr. Ferraioli is on the speakers’ bureau for Canon Medical Systems, Hitachi, Mindray Medical Systems, and Philips Ultrasound. To the Editor: I have read with great interest the article by Younossi et al.(1) and would like to express my gratitude for giving a thorough insight on the diagnostic modalities for assessing nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis, and associated fibrosis. As underlined by the authors, a subgroup of NAFLD patients will develop liver fibrosis, which predicts mortality. Due to the high prevalence of NAFLD in the general population worldwide, the noninvasive methods for staging liver fibrosis are highly attractive and cost‐effective. On the paragraph about the role of the radiologic modalities, incorrect information about the available ultrasound (US) elastography techniques for the assessment of liver stiffness is given. This mistake is reiterated several times in the literature, despite the clarification made by guidelines that have detailed the technical principles of all US elastography techniques available as of today.(2) Indeed, the use of correct terminology is an essential prerequisite to allow effective and appropriate comparison among the different available technologies. The widely used US‐based elastography techniques for the assessment of liver elasticity are based on the generation of shear wave by an external or internal mechanical push and are termed “shear wave elastography” (SWE).(2) Transient elastography is a SWE technique that makes use of an external mechanical push to generate shear waves that propagate into the liver and is performed with a dedicated device, the FibroScan (Echosens, Paris, France). With the SWE techniques incorporated in the US systems, the shear waves are generated by an internal acoustical push pulse made by the acoustic radiation force impulse (ARFI) (i.e., the force of the ultrasound beam) directly into the liver. The assessment of shear wave speed/stiffness is made either at one point as in point SWE or, using several ARFI lines, it is possible to obtain quantitative images of the elasticity, as in 2D SWE. The term “acoustic radial force imaging” identifies a completely different elastography technique that is not based on the generation of the shear waves and is not used for the assessment of diffuse liver disease.(4)

Hepatic fibrosis: US elastography vs. MR elastography

Hepatic fibrosis is final results of a wide variety of types of liver injury and is a consequence of all chronic liver diseases and progresses more or less rapidly towards cirrhosis, and finally cancer. In terms of the tools used to quantitate fibrosis today, there are three kinds of tools; biochemical markers, conventional imaging, and functional imaging such as elastography (E) or stiffness imaging. Recent imaging tools for evaluation of hepatic fibrosis are US based techniques, MR based techniques, and perfusion imaging. US Elastography (USE) is classified into strain-based E and SW-based E. Strain-based E is subclassified into Static USE (Manual compression of the tissue) and Quasi-static USE (Physiologic vibrations (heartbeat, blood vessels pulse). SW-based E is subclassified into 1D such as fibroscan (Echosens), Point E such as virtual touch quantification (Siemens). ElastPQ (Philips) and 2D SWE such as supersonic shear imaging (Supersonic Imagine), and shear wave elastography (GE, Toshiba)). For the liver, USE is divided into 2 categories quasi-static E and shear wave based imaging. Quasi-static E is not popular. Shear wave based imaging is subdivided into two types based on generation method of shear wave: Controlled external vibration with a vibrator and acoustic radiation force impulse. Transient elastography is using mechanical push, and both ARFI imaging and supersonic shear wave elastography are using ARFI. Strengths of 1D SW-based elastography are the most extensively investigated technique with high portability. Limitations are no B-mode imaging, high technical failure rate (2.4-9.4%) and narrow applications outside of liver investigation. Strengths of point SW-based elastography are low technical failure rate ( In Summary, liver stiffness is determined by matrix deposition (fibrosis) and pressure change (hydrostatic, osmotic). Hepatic fibrosis (HF) is a consequence of all chronic liver diseases and progresses towards cirrhosis and finally cancer. Noninvasive diagnosis and staging is important clinical issue for hepatic fibrosis which is reversible. Elastrography is clinically acceptable for the prediction of liver fibrosis (≥F2) and confounders of stiffness measurement (intercostal approach to right lobe (S7/8), 1-3 cm below the liver capsule, biologic confounders can change stiffness values, fasting at least 2 hours, breath-hold at expiration). Elastography is one of important noninvasive methods to quantify HF more sensitively and objectively. USE is the first line examination for the assessment of HF. MRE is the second line examination, especially in cirrhosis. To avoid confounders of liver stiffness, comprehensive other imaging exams are needed.

Two-dimensional shear wave elastography for differential diagnosis between mastitis and breast malignancy.

To determine the diagnostic performance of conventional ultrasound (US) and two-dimensional shear wave elastography (2D SWE) in the differential diagnosis between mastitis and breast malignancy. Between January 2016 and March 2017, 105 patients with 105 pathologically proven breast lesions were enrolled. All the lesions were subject to conventional US and 2D SWE examinations. In 2D SWE, the qualitative parameter of stiff rim sign and quantitative parameter of maximal shear wave velocity (SWV) were obtained. The diagnosis performances of US and combination of US and 2D SWE were evaluated, including sensitivity, specificity and the area under the receiver operating characteristic curve (AUROC). The AUROC of US and the combined method were also evaluated in subgroups with different diameters. Pathologically, 26 breast lesions were confirmed to be mastitis and 79 were malignant. The cut-off value for maximal SWV was 6.75 m/sec. The AUROC of stiff rim sign and maximal SWV were 0.701 (95% CI: 0.587-0.815) and 0.753 (95% CI: 0.659-0.832) respectively. Compared with US, the specificity and AUROC of the combined method increased significantly (specificity: 11.5% vs. 96.1%, AUROC: 0.520 vs. 0.752; both P < 0.05). The combination of US and 2D SWE improved the diagnostic performance in the differential diagnosis between mastitis and breast malignancy in comparison with the conventional US alone.

Improved Riemann solvers for an accurate resolution of 1D and 2D shock profiles with application to hydraulic jumps

From the early stages of CFD, the computation of shocks using Finite Volume methods has been a very challenging task as they often prompt the generation of numerical anomalies. Such anomalies lead to an incorrect and unstable representation of the discrete shock profile that may eventually ruin the whole solution. The two most widespread anomalies are the slowly-moving shock anomaly and the carbuncle, which are deeply addressed in the literature in the framework of homogeneous problems, such as Euler equations. In this work, the presence of the aforementioned anomalies is studied in the framework of the 1D and 2D SWE and novel solvers that effectively reduce both anomalies, even in cases where source terms dominate the solution, are presented. Such solvers are based on the augmented Roe (ARoe) family of Riemann solvers, which account for the source term as an extra wave in the eigenstructure of the system. The novel method proposed here is based on the ARoe solver in combination with: (a) an improved flux extrapolation method based on a previous work, which circumvents the slowly-moving shock anomaly and (b) a contact wave smearing technique that avoids the carbuncle. The resulting method is able to eliminate the slowly-moving shock anomaly for 1D steady cases with source term. When dealing with 2D cases, the novel method proves to handle complex shock structures composed of hydraulic jumps over irregular bathymetries, avoiding the presence of the aforementioned anomalies.

The Evaluation of Liver Fibrosis in the Real-Time Shear Wave Elastography Technique in Chronic Hepatitis B and C Patients: How Many Measurements Are Necessary to Assign Patients to METAVIR Score Properly?

Background Hepatic fibrosis is part of chronic liver disorders such as chronic hepatitis, cirrhosis, or metabolic disorders. Two-dimensional shear wave elastography (2D SWE) is one of the newest elastography techniques, which enables the assessment of the liver fibrosis in a non-invasive way.Objectives The aim of the study was to determine how many measurements are necessary to assess liver fibrosis in a healthy population and patients with hepatitis B and C.Methods We analyzed the retrospective data of 642 patients who underwent the complex ultrasonic abdomen examination and liver 2D SWE examination. We analyzed the statistical differences and the interclass correlation coefficient between the value of the first measurement, the median value of the first three measurements, and the median value of all five measurements.Results There was no statistical difference between the 2D SWE value of the first measurement and the median value of the first three and the first five measurements in healthy controls. In the group of patients with hepatitis B, the median value of the first five 2D SWE measurements was significantly higher than the value of the first 2D SWE measurement. Our study presented no statistical difference between the median of the first three measurements and the median value of all five measurements in the group of HCV positive patients. The analysis of the assignment to the METAVIR groups with respect to the median value of the first three 2D SWE measurements revealed no statistical difference in comparison with the assignment of patients with respect to the all five 2D SWE measurements of the liver.Conclusions Depending on the patients’ condition, different numbers of 2D SWE measurements can affect the median values of liver stiffness although they do not affect the assignment to the METAVIR scale.

2D shear wave elastography combined with MELD improved prognostic accuracy in patients with acute-on-chronic hepatitis B liver failure.

To evaluate accuracy of two-dimensional shear wave elastography (2D SWE) and develop and validate a new prognostic score in predicting prognosis of acute-on-chronic liver failure (ACLF) patients. From 1 October 2013 to 30 September 2015, we consecutively enrolled 290 patients, sequentially collected data (including 2D SWE, ultrasound parameters, laboratory data and prognostic scores) and recorded patients' outcome (recovering/steady or worsening) during a 90-day follow-up period. We evaluated ability of 2D SWE to predict outcomes of acute-on-chronic hepatitis B liver failure (ACLF-HBV) patients. We developed a new score (MELD-SWE, combining MELD and SWE values) for predicting mortality risk of ACLF-HBV in 179 patients in a derivation group, and validated in 111 patients. 2D SWE values were higher in worsening patients than recovering/steady ones (p < 0.001). Accuracy of 2D SWE in predicting outcomes of ACLF-HBV was comparable to that of the MELD score (p = 0.441). MELD-SWE showed a significantly higher prognostic value than MELD in both derivation (AUROC, 0.80 vs. 0.76, p = 0.040) and validation (AUROC, 0.87 vs. 0.82, p = 0.018) group. The MELD-SWE score, combining MELD and SWE values, was superior to MELD alone for outcoming prediction in patients with ACLF-HBV. • 2D SWE is a simple prognostic evaluation tool in patients with ACLF-HBV. • MELD-SWE was created in this study: 1.3×MELD + 0.3×2D SWE (kPa). • MELD-SWE score was superior to MELD alone for outcoming prediction in ACLF-HBV. • In this study, 46.8 was the optimal cut-off value of MELD-SWE score.

Accuracy of 2D shear wave elastography in the diagnosis of liver fibrosis in patients with chronic hepatitis C.

This prospective study was conducted to assess the diagnostic accuracy of two-dimensional shear wave elastography (2D SWE) in the diagnosis of liver fibrosis in patients with chronic liver disease and hepatitis C virus (HCV) compared with the serum liver fibrosis biomarkers using the results of liver biopsy as the reference standard. We analyzed 233 consecutive HCV patients. On the same day, 2D SWE m, biochemical tests, and liver biopsy were performed. We used the METAVIR staging system and receiver operating characteristic curves for the analysis. The success rate of 2D-SWE was 98.7%. The median shear wave velocities (SWVs) of patients in the F0, F1, F2, F3, and F4 stages were 1.35 m/s, 1.42 m/s, 1.58 m/s, 1.83 m/s, and 2.13 m/s, respectively, demonstrating a stepwise increase (P < .0001). The accuracy of 2D-SWE in the prediction of ≥F1, ≥F2, ≥F3, and F4 was .888 (95% CI: .85-.93), .915 (95% CI: .88-095), .940 (95% CI: .91-.97), and .949 (95% CI: .92-.97), respectively. 2D-SWE was significantly superior to serum liver fibrosis biomarkers. 2D-SWE was positively correlated with the severity of liver fibrosis and was more useful for to predict all liver fibrosis grades in HCV patients than liver fibrosis biomarkers.

SAT-071 - Liver stiffness measurement by 2D SWE from General Electric is similar with Transient Elastography in clinical significant portal hypertension diagnosis

SAT-071 - Liver stiffness measurement by 2D SWE from General Electric is similar with Transient Elastography in clinical significant portal hypertension diagnosis

Toward Sustainable Management: 2D Modelling of a Self-Cleaning System to Improve Geometry in Front of the Flushing Gate

This paper aims to show how numerical modelling based on 2D SWE can be used to analyze the cleaning effectiveness of flushing waves in storm tanks. The case study under consideration is an existing storm tank located in Badalona, a municipality of Barcelona, Spain. Storm tank cleaning systems are critical features that must be carefully addressed. If not appropriately addressed, operation and maintenance work costs can drastically increase. There are numerous currently available technologies for cleaning storage tanks. However, no specific guide on this field has been identified. References are provided by the manufacturers through their commercial catalogues. Generally, this information is not based on experimental or numerical experiences or results have not been published in the literature of scientific papers. In this study, a public domain software (IBER) was used to develop 2D hydraulic analysis of the selected tank. The results obtained show how the phenomenon of recirculation is acting in some areas of the lane. This implies a dissipation of energy, thus causing difficulties in terms of cleaning procedures. Furthermore, two new scenarios have been tested to determine how a different lane width might affect hydrodynamic behavior. A newly suggested geometry for the existing lane of the tank is proposed by using the numerical modeling software. The proposed geometry in the current pilot tank achieves higher velocities and avoids recirculation areas. The results demonstrate that numerical modelling of these types of processes is possible with the computer models available (commercial codes) and can be used to optimize cleaning system design.

The Possibility of Forecast an Expressed Intraoperative Bleeding During Transurethral Resection of the Prostate using Preoperative Transrectal Ultrasound

There is no doubt about the prevalence rate of benign prostate hyperplasia. Currently, transurethral prostate resection (TUR) is the main method of surgical treatment. To clarify the degree of possible intraoperative bleeding, we assume the application of pre-hospital transrectal ultrasonic prostate examination (TRU) with vascular Doppler and 2D Shear Wave elastography.The aim: to evaluate the possibilities of preoperative complex TRU prostate examination in forecasting of the expressed intraoperative bleeding.Materials and methods. The study included the results of a survey of 242 patients in the urological Department of the road clinical hospital of Rostov-on-don in the period from 2016 to 2017, which had undergone TUR of the prostate. All patients before the operation was performed prostate transrectal ultrasonography (TRU) with Doppler and 2D Shear Wave Elastography (2DSWE). Depending on the amount of blood loss determined after surgery, all patients were divided into three statistically (p &lt; 0.001) significant groups (р &lt; 0.001). All TRU examinations were made with ultrasound system Aixplorer (France). During Doppler sonography, maximal linear blood flow velocity (Vmax) in capsular arteries (CA), in “surgical capsule” arteries (SCA) and in the paraurethral artery (PuA) was measured. During 2D Sheare Wave elastography (2D SWE) stiffness of tissues was measured (in kPa) in symmetric areas of both lobes of peripheral zone (PPZ), central zone (CZ), and transitory zone (TZ) of prostateResults. Significant (p &lt; 0.001) correlation of blood loss with reduction of hemoglobin level, as well as with Vmax CA, Vmax PuA, tissue stiffness TZ and areas on the border with the surgical capsule revealed. The ROC analysis showed, that sensitivity and specificity of predictions of severe intraoperative blood loss, when using a cut-off for the Vmax of the blood flow in CA more 18.7 cm/s, was respectively 87.2% and 94.4 per cent; when using a cut-off for the Vmax of the blood flow in the basin PUA over 24.2 cm/s – respectively of 76.6% and 78.5%; when using a cut-off of stiffness of the tissues TZ less of 39.8 kPa – respectively 100% and 95.4%: when using a cut-off of stiffness of the tissues at the border of the “surgical capsule” less than the 38.1 kPa – respectively 89,4% and 90,8%.Conclusion.The use of cut-off Vmax values for the blood flow in the paraurethral and capsular arteries, as well as the use of cut-off values for tissue stiffness in the prostate transitory zone of prostate and in the surgical capsule area, may be an effective means of forecasting of expressed intraoperative bleeding. The data presented is recommended to take into account the operating surgeon during the selection of patients for operative benefits.