2D Shear Wave Research Articles

Seismic site conditions of RESNOM network

The Northwest Seismic Network of Mexico (RESNOM) is operated by personnel from the Center for Scientific Research and Higher Education of Ensenada, Baja California (CICESE), which supervises station installation, improvement, and maintenance. We employed seismic noise and the Horizontal to Vertical Spectral Ratio (HVSR) method to determine, for each station, the following site condition parameters: the depth of the rock layer (Heng_bed), and the geotechnical parameter VS30, obtained from 1D shear wave velocity models. Other parameters as the fundamental frequency (f0) and the average amplitude at the fundamental frequency (A0) were also estimated. Our results show clear differences between the values obtained for the Mexicali Valley and the Peninsular ranges regions. The VS30 obtained for stations of the Mexicali Valley region falls in the range from 173 m/s to 535 m/s, while for the Peninsular Ranges region is between 213 m/s and 958 m/s. Regarding the Heng_bed parameter, the values are similar between both regions, from 23 m to 850 m for the Peninsular and from 42 m to 926 m for the Mexicali Valley. Additionally, from the VS30 values, we propose the site classification according to the U.S. National Earthquake Hazards Reduction Program (NEHRP).

Performance of ultrasound-guided attenuation parameter and 2D shear wave elastography in patients with metabolic dysfunction-associated steatotic liver disease.

To assess the performance and the reproducibility of ultrasound-guided attenuation parameter (UGAP) and two-dimensional shear wave elastography (2D-SWE) in patients with biopsy-proven metabolic dysfunction-associated steatotic liver disease (MASLD). This study included consecutive adult patients with MASLD who underwent ultrasound with UGAP, 2D-SWE and percutaneous liver biopsy. The median values of 12 consecutive UGAP measurements were acquired by two independent radiologists (R1 and R2). Hepatic steatosis was graded by liver biopsy as: (0) < 5%; (1) 5-33%; (2) > 33-66%; (3) > 66%. Areas under the curve (AUCs) were calculated to determine the diagnostic performance. Inter- and intra-observer reliability was assessed with intraclass correlation coefficient (ICC). A hundred patients (median age 55.0 years old) with MASLD were prospectively enrolled. At histopathology, 70 and 42 patients had grade ≥ 2 and 3 steatosis, respectively. Median UGAP was 0.78 dB/cm/MHz (IQR/Med: 5.55%). For the diagnosis of grade ≥ 2 steatosis, the AUCs of UGAP were 0.828 (95% CI: 0.739, 0.896) for R1 and 0.779 (95% CI: 0.685, 0.856) for R2. The inter- and intra-operator reliability of UGAP were excellent, with an ICC of 0.92 (95% CI: 0.87-0.95) and 0.95 (95% CI: 0.92-0.96), respectively. The median liver stiffness was 6.76 kPa (IQR/Med: 16.30%). For the diagnosis of advanced fibrosis, 2D-SWE had an AUC of 0.862 (95% CI: 0.757, 0.934), and the optimal cutoff value was > 6.75 kPa with a sensitivity of 80.6% and a specificity of 75.7%. UGAP and 2D-SWE provide a good performance for the staging of steatosis and fibrosis in patients with MASLD with an excellent intra-operator reliability of UGAP. Question How well do ultrasound-guided attenuation parameter (UGAP) and two-dimensional shear wave elastography (2D-SWE) perform for quantifying hepatic steatosis and fibrosis? Findings UGAP had a maximum AUC of 0.828 for the diagnosis of grade ≥ 2 steatosis, and 2D-SWE had an AUC of 0.862 for diagnosing advanced fibrosis. Clinical relevance UGAP and 2D-SWE allow rapid, reproducible, and accurate quantification of hepatic steatosis and fibrosis that can be used for the noninvasive assessment of patients with metabolic dysfunction-associated steatotic liver disease.

2D Shear Wave Elastography of Normal Thyroid Gland in Nepalese Population

Ultrasonography (USG) is modality of choice for normal, diffuse or nodular thyroid diseases. Two dimensional shear wave elastography (2D-SWE) is the latest innovation in USG techniques that allows real-time quantitative assessment of tissue stiffness using acoustic radiation force impulse (ARFI) induced by ultrafast focused US beam sequence (up to 20,000Hz) to record the propagation of the shear waves in real time and displays a map that represents the local elasticity values of tissues in real-time and in a quantitative manner without any compression of the organ. At times, there are difficulties in differentiating normal thyroid gland from diffuse thyroid disease based solely on gray scale USG for which 2D-SWE can be an adjunct. This study aims to establish 2D-SWE parameters for normal thyroid gland in Nepalese population. A cross sectional descriptive study was carried out with 2D SWE on all euthyroid patients with normal thyroid gland on B-mode USG at Department of Radiology, Nepal Medical College Teaching Hospital between December 2021 and November 2022. Tissue stiffness of normal thyroid gland was recorded and tabulated in terms of SMV units (m/s) according age and gender. Out of 100 subjects ( 52 females and 48 males) the youngest was 16 year female and oldest was 68 year female with mean age of 37.07 year (S.D = 11.58). Minimum mean velocity of 1.78 m/s was seen in 36 year old male and maximum of 3.40 m/s in 26 year old female. Mean of mean velocity was 2.36 m/s with (S.D= 0.34). Linear positive correlation was seen between shear wave velocities and age with no statistically significant difference between genders. This study had the most number of normal subjects (100) with almost equal gender distribution (52 females and 48 males) compared to previous studies in known literature. This study also analyzed correlation of shear wave velocity with age unlike other studies. Statistically significant correlation was seen between age and velocities in males only and also in mean velocities between age group 21-40 and 41-60 years (p-value= 0.037).

Crustal structure of the Bushveld complex, South Africa from 1D shear wave velocity models: Evidence for complex-wide crustal modification

Thirty-nine 1D shear wave velocity profiles, obtained by jointly inverting receiver functions and Rayleigh wave group velocities, are used to investigate the crustal structure of the Bushveld Complex in northern South Africa. Data from teleseismic earthquakes recorded on broadband seismic stations between 1997 and 1999 and 2015–2020 were used to compute P-wave receiver functions. Rayleigh wave group velocities between 5 and 30 s period were obtained from an ambient noise tomography and combined with group velocities between 30 and 60 s period from a published continental-scale surface wave tomography model. Moho depths of 45–47.5 km are found under the center of the complex compared to 40 km thick crust, on average, surrounding the complex, indicating ∼5–7 of crustal thickening. The bottom ∼10 km or more of the lower crust across much of the Bushveld Complex has a Vs ≥ 4.0 km/s, consistent with a mafic composition, whereas in most areas around the margins of the complex the thickness of the mafic lower crust is much less than 10 km. In the upper crust higher velocity structure (Vs > 3.6 km/s) above 15 km depth underlain by lower velocity structure is seen in many locations, suggesting the presence of mafic/ultramafic layering. These results favor the continuous-sheet model for the structure of the Bushveld Complex because the ensemble of 1D models is characterized by three diagnostic features consistent with that model: (1) thicker crust under the center of the complex than away from the complex; (2) a greater thickness of high-velocity (i.e., mafic) layering in the lower crust under the complex compared to away from the complex; (3) high-velocity (i.e., mafic/ultramafic) layering in the upper crust beneath much of the complex. The lack of upper crustal mafic/ultramafic layering beneath some parts of the complex is consistent with the post-emplacement tectonic and magmatic history of the complex.

B-mode, Doppler, and Elastography abdominal ultrasound in Tamandua tetradactyla.

The aim of this study was to describe the normal B-mode, Doppler, and 2D Shear Wave Elastography ultrasonographic findings of some abdominal structures in a six-month-old male Southern Tamandua (Tamandua tetradactyla). The animal was found and rescued by the environmental police after being discovered in the wild near its mother, who had died in a car accident. For the ultrasonographic exams, the animal's abdominal region was shaved, and only physical restraint was used. In the B-mode exam, the urinary bladder, small intestine, kidneys, left adrenal gland, stomach, liver, and gallbladder were located and evaluated. Doppler examination obtained spectral tracings of the arcuate and renal arteries of both kidneys. Elastography assessed the stiffness of the renal cortex, liver, and spleen. The ultrasound examination provided an adequate evaluation and novel findings of the Southern Tamandua abdominal structures without invasiveness.

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

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. 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. 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. 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.

Breast multiparametric ultrasound: a single-center experience.

To evaluate the role of multiparametric ultrasound (mpUS) in the characterization of focal breast lesions (FBLs). This prospective study enrolled patients undergoing multiparametric breast ultrasound for FBLs. An experienced breast radiologist evaluated the following ultrasound features: US BI-RADS category, vascularization pattern (internal, vessels in rim and combined) and presence of penetrating vessels with each Doppler method (Color-Doppler, Power-Doppler, Microvascular imaging), strain ratio (SR) and Tsukuba score (TS) with Strain Elastography (SE), Emax, Emean, Emin and Eratio with 2D-shear wave elastography (2D-SWE). Core biopsy for all BI-RADS 4-5 FBLs and 24-month follow-up for all BI-RADS 2-3 FBLs were considered for standard of reference. The diagnostic performance was assessed with the area under curve (AUCs) and cut-off values were determined according to the Youden's index. A total of 139 FBLs were included with 75/139 (53.9%) benign and 64/139 (46.1%) malignant FBLs. Internal vascularization patterns (p < 0.001), penetrating vessels (p < 0.001), TS 4-5 (p < 0.001) and all 2D-SWE parameters (p < 0.001) were significantly different between benign and malignant FBLs. The BI-RADS score provided an AUC of 0.876 (95% CI 0.810-0.926) for the diagnosis of malignant FBLs. Among the 2D-SWE measurements, an excellent diagnostic performance was observed for Emax with an AUC of 0.915 (95% CI 0.856-0.956) and Emean of 0.908 (95% CI 0.847-0.951). Optimal cutoff for the diagnosis of malignant FBLs were US BI-RADS > 3, Strain Ratio > 2.52, Tsukuba Score > 3, Emax > 82.6kPa, Emean > 66.0kPa, Emin > 54.4kPa and Eratio > 330.8. Multiparametric ultrasound, particularly SWE, can improve specificity in the characterization of FBLs.

Quality Assurance of Point and 2D Shear Wave Elastography through the Establishment of Baseline Data Using Phantoms.

Ultrasound elastography has been available on most modern systems; however, the implementation of quality processes tends to be ad hoc. It is essential for a medical physicist to benchmark elastography measurements on each system and track them over time, especially after major software upgrades or repairs. This study aims to establish baseline data using phantoms and monitor them for quality assurance in elastography. In this paper, we utilized two phantoms: a set of cylinders, each with a composite material with varying Young's moduli, and an anthropomorphic abdominal phantom containing a liver modeled to represent early-stage fibrosis. These phantoms were imaged using three ultrasound manufacturers' elastography functions with either point or 2D elastography. The abdominal phantom was also imaged using magnetic resonance elastography (MRE) as it is recognized as the non-invasive gold standard for staging liver fibrosis. The scaling factor was determined based on the data acquired using MR and US elastography from the same vendor. The ultrasound elastography measurements showed inconsistency between different manufacturers, but within the same manufacturer, the measurements showed high repeatability. In conclusion, we have established baseline data for quality assurance procedures and specified the criteria for the acceptable range in liver fibrosis phantoms during routine testing.

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.

Predicting hepatocellular carcinoma: A new non-invasive model based on shear wave elastography.

Integrating conventional ultrasound features with 2D shear wave elastography (2D-SWE) can potentially enhance preoperative hepatocellular carcinoma (HCC) predictions. To develop a 2D-SWE-based predictive model for preoperative identification of HCC. A retrospective analysis of 884 patients who underwent liver resection and pathology evaluation from February 2021 to August 2023 was conducted at the Oriental Hepatobiliary Surgery Hospital. The patients were divided into the modeling group (n = 720) and the control group (n = 164). The study included conventional ultrasound, 2D-SWE, and preoperative laboratory tests. Multiple logistic regression was used to identify independent predictive factors for malignant liver lesions, which were then depicted as nomograms. In the modeling group analysis, maximal elasticity (Emax) of tumors and their peripheries, platelet count, cirrhosis, and blood flow were independent risk indicators for malignancies. These factors yielded an area under the curve of 0.77 (95% confidence interval: 0.73-0.81) with 84% sensitivity and 61% specificity. The model demonstrated good calibration in both the construction and validation cohorts, as shown by the calibration graph and Hosmer-Lemeshow test (P = 0.683 and P = 0.658, respectively). Additionally, the mean elasticity (Emean) of the tumor periphery was identified as a risk factor for microvascular invasion (MVI) in malignant liver tumors (P = 0.003). Patients receiving antiviral treatment differed significantly in platelet count (P = 0.002), Emax of tumors (P = 0.033), Emean of tumors (P = 0.042), Emax at tumor periphery (P < 0.001), and Emean at tumor periphery (P = 0.003). 2D-SWE's hardness value serves as a valuable marker for enhancing the preoperative diagnosis of malignant liver lesions, correlating significantly with MVI and antiviral treatment efficacy.

3D shear wave velocity and azimuthal anisotropy structure in the shallow crust of Binchuan Basin in Yunnan, Southwest China, from ambient noise tomography

The Binchuan Basin in northwest Yunnan, southwest China, is a rift basin developed at the intersection of the Red River Fault and Chenghai Fault, where historical earthquakes have occurred. Understanding the fine velocity structure of the shallow crust in this region can help improve earthquake location accuracy and our understanding of the relationship between fault zone structures and fault slip behaviors. Using the continuous waveform data recorded by 381 dense array stations in 2017, we obtained 7 915 Rayleigh-wave phase velocity dispersion curves in the period band of 0.2–6 ​s from ambient noise cross-correlation functions after rigorous data processing and quality control. We determined 3D isotropic and azimuthally anisotropic shear wave velocity models at depths above 6 ​km in the shallow crust based on the direct surface wave azimuthal anisotropic tomography method. The isotropic model reveals a strong correspondence between the S-wave velocity structure at depths of 0–1 ​km and the regional topography and lithology. The Binchuan depocenter, Zhoucheng depocenter, Xiangyun Basin, and Xihai Rift Basin are primarily composed of Quaternary deposits, which show low-velocity anomalies, while the regions with the Paleozoic shale, limestone, and basalt exhibit high-velocity anomalies. The nearly N–S orientation of fast directions from azimuthal anisotropy models are mainly controlled by the active Binchuan Fault with N–S strike as well as the NNW-oriented primary compressive stress.

#613 Is there a relationship between kidney stiffness identified by 2D shear wave elastography and the estimated glomerular filtration rate?

Abstract Background and Aims Ultrasound-based elastography has been utilized as an imaging method with high utility in the liver or thyroid, but it is not yet being implemented in evaluating the chronic kidney disease (CKD) because current research indicates a high level of heterogeneity between studies. We aimed to investigate if there is a connection between kidney stiffness measured with a new, specially designed elastography software for kidneys and estimated glomerular filtration rate (eGFR). Method In 2022 and 2023 we performed a cross-sectional study in 150 participants (50 healthy, 50 kidney-transplanted, 50 with chronic glomerulonephritis). The mean value of five different measurements for each kidney were correlated with biological and clinical parameters. To examine the variations amongst the three groups, one-way between-groups ANOVA was employed. Results The mean kidney stiffness for the healthy cohort was 31.9 ± 2.9 kiloPascal (kPa), for kidney transplanted (Ktx) patients 25.9 ± 6.9 kPa and for the chronic glomerulonephritis (GN) 23.8 ± 7.45 kPa. We discovered correlations between kidney stiffness and eGFR in all three groups: healthy r = 0.61, p &amp;lt; 0.0001, Ktx r = 0.56, p &amp;lt; 0.0001, GN r = 0.70, p &amp;lt; 0.0001. We also found a value of under 26 kPa for the detection of an eGFR under 60 mL/min/1.73 m2 with 94.3% sensitivity and 84% specificity (AUC = 0.905, p &amp;lt; 0.0001). The healthy group showed significant higher values than Ktx or GN groups, but without significant differences between the latter two. Conclusion Our findings demonstrate a correlation between renal function, with very good diagnostic accuracy, and these novel imaging techniques. A decrease in renal stiffness with the progression of CKD could prove to be an easy, reproducible approach to provide additional diagnostic information. However, given the limited number of participants, additional studies are required before they can be incorporated into standard clinical practice.

3D Ultrasound Shear Wave Elastography for Musculoskeletal Tissue Assessment Under Compressive Load: A Feasibility Study.

Given its real-time capability to quantify mechanical tissue properties, ultrasound shear wave elastography holds significant promise in clinical musculoskeletal imaging. However, existing shear wave elastography methods fall short in enabling full-limb analysis of 3D anatomical structures under diverse loading conditions, and may introduce measurement bias due to sonographer-applied force on the transducer. These limitations pose numerous challenges, particularly for 3D computational biomechanical tissue modeling in areas like prosthetic socket design. In this feasibility study, a clinical linear ultrasound transducer system with integrated shear wave elastography capabilities was utilized to scan both a calibrated phantom and human limbs in a water tank imaging setup. By conducting 2D and 3D scans under varying compressive loads, this study demonstrates the feasibility of volumetric ultrasound shear wave elastography of human limbs. Our preliminary results showcase a potential method for evaluating 3D spatially varying tissue properties, offering future extensions to computational biomechanical modeling of tissue for various clinical scenarios.

3D shear wave velocity imaging of the subsurface structure of granite rocks in the arid climate of Pan de Azúcar, Chile, revealed by Bayesian inversion of HVSR curves

Abstract. Seismic methods are emerging as efficient tools for imaging the subsurface to investigate the weathering zone. The structure of the weathering zone can be identified by differing shear wave velocities as various weathering processes will alter the properties of rocks. Currently, 3D subsurface modelling of the weathering zone is gaining increasing importance as results allow the identification of the weathering imprint in the subsurface not only from top to bottom but also in three dimensions. We investigated the 3D weathering structure of monzogranite bedrock near the Pan de Azúcar National Park (Atacama Desert, northern Chile), where the weathering is weak due to the arid climate conditions. We set up an array measurement that records seismic ambient noise, which we used to extract the horizontal-to-vertical spectral ratio (HVSR) curves. The curves were then used to invert for 1D shear wave velocity (Vs) models, which we then used to compile a pseudo-3D model of the subsurface structure in our study area. To invert the 1D Vs model, we applied a transdimensional hierarchical Bayesian inversion scheme, allowing us to invert the HVSR curve with minimal prior information. The resulting 3D model allowed us to image the granite gradient from the surface down to ca. 50 m depth and confirmed the presence of dikes of mafic composition intruding the granite. We identified three main zones of fractured granite, altered granite, and the granite bedrock in addition to the mafic dikes with relatively higher Vs. The fractured granite layer was identified with Vs of 1.4 km s−1 at 30–40 m depth, while the granite bedrock was delineated with Vs of 2.5 km s−1 and a depth range between 10 and 50 m depth. We compared the resulting subsurface structure to other sites in the Chilean coastal cordillera located in various climatic conditions and found that the weathering depth and structure at a given location depend on a complex interaction between surface processes such as precipitation rate, tectonic uplift and fracturing, and erosion. Moreover, these local geological features such as the intrusion of mafic dikes can create significant spatial variations to the weathering structure and therefore emphasize the importance of 3D imaging of the weathering structure. The imaged structure of the subsurface in Pan de Azúcar provides the unique opportunity to image the heterogeneities of a rock preconditioned for weathering but one that has never experienced extensive weathering given the absence of precipitation.

Ultrasound Shear Elastography With Expanded Bandwidth (USEWEB): A Novel Method for 2D Shear Phase Velocity Imaging of Soft Tissues.

Ultrasound shear wave elastography (SWE) is a noninvasive approach for evaluating mechanical properties of soft tissues. In SWE either group velocity measured in the time-domain or phase velocity measured in the frequency-domain can be reported. Frequency-domain methods have the advantage over time-domain methods in providing a response for a specific frequency, while time-domain methods average the wave velocity over the entire frequency band. Current frequency-domain approaches struggle to reconstruct SWE images over full frequency bandwidth. This is especially important in the case of viscoelastic tissues, where tissue viscoelasticity is often studied by analyzing the shear wave phase velocity dispersion. For characterizing cancerous lesions, it has been shown that considerable biases can occur with group velocity-based measurements. However, using phase velocities at higher frequencies can provide more accurate evaluations. In this paper, we propose a new method called Ultrasound Shear Elastography with Expanded Bandwidth (USEWEB) used for two-dimensional (2D) shear wave phase velocity imaging. We tested the USEWEB method on data from homogeneous tissue-mimicking liver fibrosis phantoms, custom-made viscoelastic phantom measurements, phantoms with cylindrical inclusions experiments, and in vivo renal transplants scanned with a clinical scanner. We compared results from the USEWEB method with a Local Phase Velocity Imaging (LPVI) approach over a wide frequency range, i.e., up to 200-2000 Hz. Tests carried out revealed that the USEWEB approach provides 2D phase velocity images with a coefficient of variation below 5% over a wider frequency band for smaller processing window size in comparison to LPVI, especially in viscoelastic materials. In addition, USEWEB can produce correct phase velocity images for much higher frequencies, up to 1800 Hz, compared to LPVI, which can be used to characterize viscoelastic materials and elastic inclusions.

A Simple and Reliable 2D-Shear Wave Elastography and UltraSound Coefficient Attenuation Parameter Technique in Chronic Liver Diseases.

The performance and reliability criteria for Aixplorer MACH30 (SS) in chronic liver diseases (CLD) have not been validated. The objectives were to define the optimal procedure, the accuracy for fibrosis and steatosis diagnosis, and the reliability criteria using SS. Patients had 2D-shear wave elastography (SWE) and ultraSound-guided controlled attenuation parameter (SCAP) performed in triplicate at the mid-axillary line (MAL), posterior axillary line (PAL), and anterior axillary line (AAL). Performances of SWE and SCAP were defined using transient elastography (TE ≥ 9.5kPa) and CAP (≥ 275dB/m) using Fibroscan (FS) as reference and validated with liver biopsy (LB). FS and SS data from 203 CLD patients were analyzed (55 ± 14years; 59% male; MASLD 58%). Median TE and CAP were 6.4kPa (2.5-66.9) and 270dB/m (141-400). The best technique for the diagnosis of advanced fibrosis and significant steatosis was the median of three SWE values and three SCAP values at MAL, PAL, and AAL with an AUROC of 0.96 [95% CI 0.93-0.98] and 0.91 [95% CI 0.86-0.95]. Only skin-to-liver distance ≥ 2.4cm (p = 0.012, 95% CI 1.37-13.38) was independently associated with discordance. The accuracy of SWE (≥ 8.5kPa) and SCAP (≥ 0.44) was analyzed in 58 patients with LB. The PPV and NPV were 50% and 94%, and 71% and 88% for fibrosis and steatosis, respectively. A reliable diagnosis of advanced fibrosis and significant steatosis can be obtained with the median of three measurements in different liver portions using SS. The only non-reliable criterion is skin-to-liver distance ≥ 2.4cm.

Distribution of Normative Percentiles of Liver Stiffness Measurement Using Ultrasound Shear Wave Elastography in an Adult Asian Indian Population

Abstract Objective The aim of this study was to determine the normative percentiles for liver stiffness measurement (LSM) using shear wave elastography in an adult Asian Indian population as part of the preventive radiology initiative of the Indian Radiological and Imaging Association (IRIA). Methods LSMs were ascertained by two-dimensional (2D) shear wave elastography using the Mindray Resona series of ultrasound machines. The image quality was assessed using the motion stability index (M-STB) and reliability (RLB) map. Ten acquisitions were documented, and an interquartile range-to-median (IQR/M) ratio ≤30% kilopascal (kPa) units was considered a good-quality measurement. A subgroup of the study population without comorbidities was chosen to derive the normative percentile distribution of LSM using a generalized least squares multivariable fractional polynomial regression model that adjusted for sex and body mass index (BMI). The effectiveness of the estimated percentiles was assessed on the entire study population using the greater than 90th percentile value of the LSM as the cutoff for abnormality. Results The study included 852 people who underwent shear wave elastography from June 2022 to July 2023. The magnitude of compensated advanced chronic liver disease (cACLD) and clinically significant portal hypertension (CSPH) was 6.81% (95% confidence interval [CI]: 5.30–8.7) and 4.91% (95% CI: 3.67–6.60), respectively. The normative percentiles were estimated from 282 persons without associated comorbidity and risk factors. The mean age (standard deviation [SD]) of the normal individuals was 40.90 ± 12.92 years, and 210 (71.47%) were males. The mean age (SD) of the 570 persons excluded from the normative percentiles analysis was 47.94 (12.49) years and 72.11% were males. The sex- and BMI-adjusted age-specific 90th percentiles of LSM were 8.76, 8.78, 8.96, 8.97, 9.25, and 9.45 kPa for 18 to 20, 21 to 30, 31 to 40, 41 to 50, 51 to 60, and 61 to 70 years, respectively. Conclusion The sex- and BMI-adjusted age-specific 90th percentiles for LSM using shear wave elastography in Asian Indian adults are almost similar to the greater than 9 kPa cutoff proposed by the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement guidelines to discriminate cACLD and CSPH from normal individuals.

Evaluation of spleen stiffness by 2D shear wave elastography for ruling out high risk varices in patients with chronic advanced liver disease. A systematic review and meta-analysis

ObjectivesTo systematically review the accuracy of spleen stiffness measurement (SSM) by 2D- Shear Wave Elastography (2D-SWE) in predicting high risk for bleeding varices (HRV) in cirrhotic patients. MethodsPubMed, Embase, Web of Science, Medline, Cochrane, and Google Scholar databases were searched up to 31/05/2023 for all human studies using 2D-SWE to estimate SSM and endoscopy to detect HRV. Meta-analysis was performed using a generalized linear mixed model. Publication bias was evaluated using the funnel plot asymmetry test. The Area Under the Summarized Receiver Operating Characteristic curve (AUSROC) was estimated using the “mada” package. ResultsA total of 13 studies and 1970 patients were included. Of them, 27.8 % had HRV. The pooled sensitivity and polled specificity of SSM in detecting HRV were 90 % (95 %CI:87–92 %) and 68 % (95 %CI:58–77 %), respectively, with an AUSROC at 0.86 (95 %CI:0.82–0.90). The median cutoff value of SSM in detecting HRV was 34.2 kPa. In studies including exclusively HBV cirrhotic patients, SSM's polled sensitivity and specificity in predicting HRV was 88 % (95 %CI:82–92 %) and 73 % (95 %CI:68–78 %), respectively. The AUSROC was 0.84 (95 %CI:0.81–0.87). The number of repeated measurements per patient (<5 or ≥ 5) did not affect the method’s capability. Using Aixplorer to evaluate SSM had a higher sensitivity in ruling out HRV than other 2D-SWE devices. ConclusionsOur meta-analysis supports that SSM by 2D-SWE has a good diagnostic performance for ruling out HRV in cirrhosis.

Non-Invasive Assessment of Liver Fibrosis in Hepatitis B Patients.

The aim of this review is to provide updated information on the clinical use of non-invasive serum and imaging-based tests for fibrosis assessment in chronic hepatitis B (CHB) virus infection. In recent years, non-invasive tests (NIT) have been increasingly used to determine eligibility for treatment. Liver biopsy is still considered the gold standard for assessing inflammatory activity and fibrosis staging, but it is an invasive procedure with inherent limitations. Simple serum markers such as APRI and FIB-4 are limited by indeterminate results but remain useful initial tests for fibrosis severity if imaging elastography is not available. Point-of-care US-based elastography techniques, such as vibration-controlled transient elastography or 2D shear wave elastography, are increasingly available and have better accuracy than simple serum tests for advanced fibrosis or cirrhosis, although stiffness cut-offs are variable based on E-antigen status and inflammatory activity. Current NITs have poor diagnostic performance for following changes in fibrosis with antiviral therapy. However, NITs may have greater clinical utility for determining prognosis in patients with CHB that have advanced disease, especially for the development of hepatocellular carcinoma and/or liver decompensation. Algorithms combining serum and imaging NITs appear promising for advanced fibrosis and prognostic risk stratification.

Possible use of 2D shear wave liver elastography in new-onset ascites evaluation

BackgroundNo data on the use of 2D shear wave elastography exists regarding the evaluation of the new-onset ascites causality.AimsTo determine whether 2D shear wave elastography can help in the non-invasive assessment of the new-onset ascites cause. To assess the applicability of liver stiffness measured by 2D shear wave elastography using Esaote MyLab Nine apparatus in patients with ascites.MethodsIn 52 consecutive patients with new-onset ascites (January 2020 to October 2021), liver stiffness using 2D shear wave elastography was prospectively measured. The reliable measurements were used for further analysis. Relevant clinical and laboratory data was collected.ResultsThe calculated liver stiffness measurement cut-off value of 14.4 kPa held 94% accuracy, 100% sensitivity, and 83% specificity when determining ascites with serum ascites albumin gradient ≥11 g/L. Reliable 2D shear wave elastography success rate was 84%.Conclusions2D shear wave elastography may potentially be used to differentiate transudative from exudative ascites, especially in patients with portal hypertension and peritoneal carcinomatosis.