Advancements in the application of uterine ultrasound elastography.

PURPOSE OF REVIEW: This article reviews recent advances in ultrasound elastography in diagnosing and evaluating the normal nongravid uterus and the infertile uterus in the gynecologic patient. RECENT FINDINGS: Focusing on the most recent primary literature, studies have demonstrated new findings among a breadth of gynecologic clinical settings. Studies in the nongravid uterus have found that menopausal status, age, and menstrual phase have not been associated with changes in uterine tissue stiffness. Focusing on myometrial disease, there have been conflicting data regarding the ability to distinguish uterine fibroids from adenomyosis. One area of expanding research surrounding uterine elastography includes the infertile population, where ongoing studies attempt to provide a predictive model using shear wave elastography (SWE) in patients undergoing in-vitro fertilization. SUMMARY: Ultrasound elastography has become an increasingly studied and utilized tool in assessing physiologic and pathologic processes in the field of gynecology. Evaluating tissue stiffness through strain and SWE can serve to improve diagnosis of various uterine and cervical lesions, as well as prognosticate outcomes after fertility treatments. This growing area of research will continue to establish the role and application of ultrasound elastography into clinical practice.

Regional shear wave speeds track regional axial stress in nonuniformly loaded fibrous soft tissues.

Ligaments and tendons undergo nonuniform deformation during movement. While deformations can be imaged, it remains challenging to use such information to infer regional tissue loading. Shear wave tensiometry is a promising noninvasive technique to gauge axial stress and is premised on a tensioned beam model. However, it is unknown whether tensiometry can predict regional stress in a nonuniformly loaded structure. The objectives of this study were to (1) determine whether regional shear wave speed tracks regional axial stress in nonuniformly loaded fibrous soft tissues, and (2) determine the sensitivity of regional axial stress and shear wave speed to nonuniform load distribution and fiber alignment. We created a representative set of 12,000 dynamic finite element models of a fibrous soft tissue with probabilistic variations in fiber alignment, stiffness, and aspect ratio. In each model, we applied a randomly selected nonuniform load distribution, and then excited a shear wave and tracked its regional propagation. We found that regional shear wave speed was an excellent predictor of the regional axial stress (RMSE = 0.57 MPa) and that the nature of the regional shear wave speed-stress relationship was consistent with a tensioned beam model (R2 = 0.99). Variations in nonuniform load distribution and fiber alignment did not substantially alter the wave speed-stress relationship, particularly at higher loads. Thus, these findings suggests that shear wave tensiometry could provide a quantitative estimate of regional tissue stress in ligaments and tendons.

Investigation of correlation between shear wave elastography and lymphangiogenesis in invasive breast cancer and diagnosis of axillary lymph node metastasis.

BACKGROUND: Accurate evaluation of axillary lymph node metastasis (LNM) in breast cancer is very important. A large number of hyperplastic and dilated lymphangiogenesis cases can usually be found in the pericancerous tissue of breast cancer to promote the occurrence of tumor metastasis.Shear wave elastography (SWE) can be used as an important means for evaluating pericancerous stiffness. We determined the stiffness of the pericancerous by SWE to diagnose LNM and lymphangiogenesis in invasive breast cancer (IBC). METHODS: Patients with clinical T1-T2 stage IBC who received surgical treatment in our hospital from June 2020 to December 2020 were retrospectively enrolled. A total of 299 patients were eventually included in the preliminary study, which included an investigation of clinicopathological features, ultrasonic characteristics, and SWE parameters. Multivariable logistic regression analysis was used to establish diagnostic model and evaluated its diagnostic performance of LNM. The correlation among SWE values, collagen volume fraction (CVF), and microlymphatic density (MLD) in primary breast cancer lesions was analyzed in another 97 patients. RESULTS: The logistic regression model is Logit(P)=-1.878 + 0.992*LVI-2.010*posterior feature enhancement + 1.230*posterior feature shadowing + 0.102*posterior feature combined pattern + 0.009*Emax. The optimum cutoff value of the logistic regression model was 0.365, and the AUC (95% CI) was 0.697 (0.636-0.758); the sensitivity (70.7 vs. 54.3), positive predictive value (PPV) (54.0 vs. 50.8), negative predictive value (NPV) (76.9 vs. 69.7), and accuracy (65.2 vs. 61.9) were all higher than Emax. There was no correlation between the SWE parameters and MLD in primary breast cancer lesions. CONCLUSIONS: The logistic regression model can help us to determine LNM, thus providing more imaging basis for the selection of preoperative treatment. The SWE parameter of the primary breast cancer lesion cannot reflect the peritumoral lymphangiogenesis, and we still need to find a new ultrasonic imaging method.

Evaluation of anorectal function using real-time tissue elastography before and after preoperative chemoradiotherapy.

PURPOSE: This study aimed to clarify the relationship between changes in elasticity and anorectal function before and after chemoradiotherapy. METHODS: This is a single-center prospective cohort study (Department of Surgical Oncology, The University of Tokyo). We established a technique to quantify internal anal sphincter hardness as elasticity using transanal ultrasonography with real-time tissue elastography. Twenty-seven patients with post-chemoradiotherapy rectal cancer during 2019-2022 were included. Real-time tissue elastography with transanal ultrasonography was performed before and after chemoradiotherapy to measure internal anal sphincter hardness as "elasticity" (hardest (0) to softest (255); decreased elasticity indicated sclerotic changes). The relationship between the increase or decrease in elasticity pre- and post-chemoradiotherapy and the maximum resting pressure, maximum squeeze pressure, and Wexner score were the outcome measures. RESULTS: A decrease in elasticity was observed in 16/27 (59.3%) patients after chemoradiotherapy. Patients with and without elasticity decrease after chemoradiotherapy comprised the internal anal sphincter sclerosis and non-sclerosis groups, respectively. The maximum resting pressure post-chemoradiotherapy was significantly high in the internal anal sphincter sclerosis group (63.0 mmHg vs. 47.0 mmHg), and a majority had a worsening Wexner score (60.0% vs. 18.2%) compared with that of the non-sclerosis group. Decreasing elasticity (internal anal sphincter sclerosis) correlated with a higher maximum resting pressure (r = 0.36); no correlation was observed between the degree of elasticity change and maximum squeeze pressure. CONCLUSION: Internal anal sphincter sclerosis due to chemoradiotherapy may correlate to anorectal dysfunction.

An explainable machine learning model for prediction of high-risk nonalcoholic steatohepatitis.

Early identification of high-risk metabolic dysfunction-associated steatohepatitis (MASH) can offer patients access to novel therapeutic options and potentially decrease the risk of progression to cirrhosis. This study aimed to develop an explainable machine learning model for high-risk MASH prediction and compare its performance with well-established biomarkers. Data were derived from the National Health and Nutrition Examination Surveys (NHANES) 2017-March 2020, which included a total of 5281 adults with valid elastography measurements. We used a FAST score ≥ 0.35, calculated using liver stiffness measurement and controlled attenuation parameter values and aspartate aminotransferase levels, to identify individuals with high-risk MASH. We developed an ensemble-based machine learning XGBoost model to detect high-risk MASH and explored the model's interpretability using an explainable artificial intelligence SHAP method. The prevalence of high-risk MASH was 6.9%. Our XGBoost model achieved a high level of sensitivity (0.82), specificity (0.91), accuracy (0.90), and AUC (0.95) for identifying high-risk MASH. Our model demonstrated a superior ability to predict high-risk MASH vs. FIB-4, APRI, BARD, and MASLD fibrosis scores (AUC of 0.95 vs. 0.50, 0.50, 0.49 and 0.50, respectively). To explain the high performance of our model, we found that the top 5 predictors of high-risk MASH were ALT, GGT, platelet count, waist circumference, and age. We used an explainable ML approach to develop a clinically applicable model that outperforms commonly used clinical risk indices and could increase the identification of high-risk MASH patients in resource-limited settings.

Serum proteomic profiling of patients with compensated advanced chronic liver disease with and without clinically significant portal hypertension.

INTRODUCTION: Portal hypertension (PH) drives the progression of liver cirrhosis to decompensation and death. Hepatic venous pressure gradient (HVPG) measurement is the standard of PH quantification, and HVPG≥10 mmHg defines clinically significant PH (CSPH). We performed proteomics-based serum profiling to search for a proteomic signature of CSPH in patients with compensated advanced chronic liver disease (cACLD). MATERIALS AND METHODS: Consecutive patients with histologically confirmed cACLD and results of HVPG measurements were prospectively included. Serum samples were pooled according to the presence/absence of CSPH and analysed by liquid chromatography-mass spectrometry. Gene set enrichment analysis was performed, followed by comprehensive literature review for proteins identified with the most striking difference between the groups. RESULTS: We included 48 patients (30 with, and 18 without CSPH). Protein CD44, involved in the inflammatory response, vascular endothelial growth factor C (VEGF-C) and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), both involved in lymphangiogenesis were found solely in the CSPH group. Although identified in both groups, proteins involved in neutrophil extracellular traps (NET) formation, as well as tenascin C, autotaxin and nephronectin which mediate vascular contractility and lymphangiogenesis were more abundant in CSPH. DISCUSSION AND CONCLUSION: We propose that altered inflammatory response, including NET formation, vascular contractility and formation of new lymph vessels are key steps in PH development. Proteins such as CD44, VEGF-C, LYVE-1, tenascin C, Plasminogen activator inhibitor 1, Nephronectin, Bactericidal permeability-increasing protein, Autotaxin, Myeloperoxidase and a disintegrin and metalloproteinase with thrombospondin motifs-like protein 4 might be considered for further validation as potential therapeutic targets and candidate biomarkers of CSPH in cACLD.

Successful therapy with tenofovir disoproxil fumarate (TDF) in patients with chronic hepatitis B (CHB) does not guarantee amelioration of liver damage assessing by transient elastography. A retrospective - prospective multicenter study.

BACKGROUND: Preventing disease progression and viral suppression are the main goals of antiviral therapy in chronic hepatitis B (CHB). Liver stiffness measurement (LSM) by transient elastography is a reliable non-invasive method to assess liver fibrosis in patients with CHB. Our aim was to explore factors that may affect changes in LSMs during long term tenofovir (TDF) monotherapy in a well characterized cohort of patients with compensated CHB. METHODS: We analyzed serial LSMs in 103 adult patients with CHB who were on TDF monotherapy and had at least three LSMs over a period of 90 months. RESULTS: Twenty-five (24%) patients had advanced fibrosis at baseline. A significant decline in mean LSM between baseline and last visit (8.7 ± 6.2 kPa vs. 6.7 ± 3.3, p = 10- 3) was observed. Twenty-four (23%) patients had progression of liver fibrosis with mean increase in liver stiffness of 2.8 kPa (range: 0.2-10.2 kPa). Multivariate analysis showed that BMI ≥ 25 (OR, 0.014; 95% CI, 0.001-0.157; p = 0.001) and advanced fibrosis (OR, 5.169; 95% CI, 1.240-21.540; p = 0.024) were independently associated with a fibrosis regression of > 30% of liver stiffness compared to baseline value. CONCLUSIONS: In CHB patients TDF monotherapy resulted in liver fibrosis regression, especially in patients with advanced fibrosis. Despite the successful antiviral effect of TDF, 1 out of 4 patients had liver fibrosis progression. Obesity and advanced fibrosis at baseline were independently associated with significant liver fibrosis regression.

Predictors for liver fibrosis in non-alcoholic patients with psoriatic diseases: A multicenter cross sectional-study.

Psoriasis has been related to metabolic dysfunction-associated fatty liver disease and, liver fibrosis. This study aimed to evaluate the prevalence of liver fibrosis in psoriasis and identify predictors for fibrosis. This is a cross-sectional study conducted from December 2012 to June 2016 assessing psoriasis and psoriatic arthritis patients attended at four centers in Mexico City. Data regarding history of the skin disease, previous and current medication, and previously diagnosed liver disease was collected. Liver fibrosis was assessed with four different non-invasive methods (FIB4, APRI, NAFLD score and elastography). We compared data based on the presence of fibrosis. Adjusted-logistic regression models were performed to estimate OR and 95% CI. A total of 160 patients were included. The prevalence of significant fibrosis using elastography was 25% (n = 40), and 7.5% (n = 12) for advanced fibrosis. Patients with fibrosis had higher prevalence of obesity (60% vs 30.8%, P = 0.04), type 2 diabetes (40% vs 27.5%, P = 0.003), gamma-glutamyl transpeptidase levels (70.8±84.4 vs. 40.1±39.2, P = 0.002), and lower platelets (210.7±58.9 vs. 242.8±49.7, P = 0.0009). Multivariate analysis showed that body mass index (OR1.11, 95%CI 1.02-1.21), type 2 diabetes (OR 3.44, 95%CI 1.2-9.88), and gamma-glutamyl transpeptidase (OR 1.01, 95%CI1-1.02) were associated with the presence of fibrosis. The use of methotrexate was not associated. Patients with psoriasis are at higher risk of fibrosis. Metabolic dysfunction, rather than solely the use of hepatotoxic drugs, likely plays a major role; it may be beneficial to consider elastography regardless of the treatment used. Metabolic factors should be assessed, and lifestyle modification should be encouraged.

The therapeutic effects of ADSCs on photoaging of skin induced by UVB irradiation.

Skin photoaging affects appearance and is associated with a variety of skin diseases, even skin cancer. Therefore, the prevention and treatment of skin photoaging is very important. However, there is a lack of effective evaluation methods, so it is an urgent problem to explore a comprehensive, non-invasive and in vivo evaluation method. Adipose-derived mesenchymal stem cells (ADSCs) are widely used to improve skin conditions as easier to obtain and positive effects. Recently, as the development of ultrasound technology, skin ultrasound has been widely used. Changes in skin layer and structure can be observed by high-frequency ultrasound (HFUS). In addition, Shear wave elastography (SWE) technology can be used to monitor the change of skin hardness. However, it is necessary to further explore the ultrasound parameters in interpreting histological changes. We simulate the progression and treatment process of human skin photoaging by using UVB-induced nude mice skin photoaging model and ADSCs injection. The analysis of the degree and therapeutic effect of skin photoaging was conducted by HFUS, SWE and to verify with histopathology. Our study aims to clarify the value of HFUS combined SWE techniques in evaluating the degree and therapeutic efficacy of skin photoaging, which provides theoretical basis for diagnosis and treatment evaluation systems.

Detection of significant liver fibrosis in Chinese psoriasis patients receiving methotrexate: a comparison between transient elastography and liver histology.

INTRODUCTION: Methotrexate (MTX) is effective for treating psoriasis and psoriatic arthritis, but its potential hepatoxicity remains a concern. Liver biopsy, the gold standard for detecting MTX-induced liver injury, is invasive and carries considerable risk. Transient elastography (TE) offers a non-invasive alternative for detecting advanced liver fibrosis. This study investigated the performance of TE in detecting MTX-induced liver fibrosis among Chinese psoriasis patients, compared with liver biopsy. METHODS: This study included adult patients with clinical psoriasis. Liver stiffness measurement using TE was performed in patients receiving MTX. Exclusion criteria were known liver cirrhosis, positive viral hepatitis carrier status, or conditions influencing TE performance. Liver biopsy was performed when liver stiffness was ≥7.1 kilopascals (kPa) or when the total cumulative dose (TCD) of MTX was ≥3.5 g. RESULTS: A total of 228 patients were screened; among 34 patients who met the inclusion criteria, nine (26.5%) had significant liver fibrosis (Roenigk grade ≥3a). The area under the receiver operating characteristic curve was 0.76 (95% confidence interval=0.59-0.93; P=0.021), indicating that TE had satisfactory performance in detecting liver fibrosis. A cut-off value of 7.1 kPa of liver stiffness yielded 100% sensitivity and 68% specificity. Liver fibrosis was not correlated with the TCD of MTX or the duration of MTX use; it was significantly correlated with obesity and diabetes status (body mass index ≥30 kg/m2, waist circumference ≥138 cm, and glycated haemoglobin level ≥7.8%). CONCLUSION: Transient elastography is reliable and superior to the TCD for detecting liver fibrosis in Chinese psoriasis patients receiving MTX. Liver biopsy should be reserved for high-risk patients or patients with liver stiffness ≥11.7 kPa on TE.

Shear-wave elastography to predict hepatocellular carcinoma after hepatitis C virus eradication: A systematic review and meta-analysis.

BACKGROUND: Direct-acting antiviral agents (DAAs) are highly effective treatment for chronic hepatitis C (CHC) with a significant rate of sustained virologic response (SVR). The achievement of SVR is crucial to prevent additional liver damage and slow down fibrosis progression. The assessment of fibrosis degree can be performed with transient elastography, magnetic resonance elastography or shear-wave elastography (SWE). Liver elastography could function as a predictor for hepatocellular carcinoma (HCC) in CHC patients treated with DAAs. AIM: To explore the predictive value of SWE for HCC development after complete clearance of hepatitis C virus (HCV). METHODS: A comprehensive literature search of clinical studies was performed to identify the ability of SWE to predict HCC occurrence after HCV clearance. In accordance with the study protocol, a qualitative and quantitative analysis of the evidence was planned. RESULTS: At baseline and after 12 wk of follow-up, a trend was shown towards greater liver stiffness (LS) in those who go on to develop HCC compared to those who do not [baseline LS standardized mean difference (SMD): 1.15, 95% confidence interval (95%CI): 020-2.50; LS SMD after 12 wk: 0.83, 95%CI: 0.33-1.98]. The absence of a statistically significant difference between the mean LS in those who developed HCC or not may be related to the inability to correct for confounding factors and the absence of raw source data. There was a statistically significant LS SMD at 24 wk of follow-up between patients who developed HCC vs not (0.64; 95%CI: 0.04-1.24). CONCLUSION: SWE could be a promising tool for prediction of HCC occurrence in patients treated with DAAs. Further studies with larger cohorts and standardized timing of elastographic evaluation are needed to confirm these data.

Diagnostic utility of shear wave elastography in musculoskeletal injuries: A narrative review.

Shear wave elastography (SWE) is an emerging and promising ultrasound modality, and is more recently employed in the diagnosis of musculoskeletal (MSK) pathologies. SWE evaluates tissue stiffness by measuring the speed of propagating acoustic waves through body tissue structures. Knowing the variations in stiffness of MSK soft tissue can provide helpful diagnostic insight for the evaluation of pathology in muscles, tendons, ligaments, nerves, and other soft tissues. The goal of this review is to synthesize recent literature on the utility of SWE for MSK pathology diagnosis. This review reveals that SWE adds important diagnostic data for the evaluation of several pathologies, such as median mononeuropathy at the wrist, Achilles tendinopathy, and plantar fasciitis. The review also reveals a lack of evidence pertaining to appropriate standardization of use and the connection to reliable and valid diagnostic benefit in the clinical setting.

Dietary inflammatory index in relation to the progression of hepatic steatosis and liver fibrosis: evaluation by elastography/Fibroscan.

One of the proposed mechanisms by which nutrition influences the progression of hepatic steatosis to fibrosis is inflammation. The study investigated how the inflammatory potential of the diet affects the risk of liver damage in patients with nonalcoholic fatty liver disease (NAFLD), a condition where fat accumulates in the liver. This cross-sectional study included 170 outpatients with newly diagnosed NAFLD. This study used a device called Fibroscan® to measure the degree of liver fibrosis, which is the scarring of the liver tissue due to chronic inflammation. The study also used a tool called the Dietary Inflammatory Index (DII) to measure the inflammatory potential of the diet based on the intake of different foods and nutrients. In the findings of the study, patients with more severe fat accumulation in the liver (hepatic steatosis) had higher DII scores, meaning they had more inflammatory diets. The study also found that higher DII scores were associated with higher weight and body mass index (BMI). One standard deviation (SD) increase in DII scores was associated with a 0.29 kilopascal (95% CI: 0.10-0.44; P-value 0.001) increase in the mean liver stiffness, an indicator of liver fibrosis. The study concluded that patients with higher DII scores had a higher risk of developing liver fibrosis than those with lower DII scores, even after adjusting for confounding factors (odds ratio: 5.89; P-value: 0.001). The study suggested that eating less inflammatory foods may help prevent or slow down the progression of hepatic steatosis and liver in patients with NAFLD.

The association between atherogenic index of plasma and metabolic dysfunction-associated fatty liver disease as detected by FibroScan / Asociación entre el índice aterogénico del plasma y la enfermedad hepática grasa asociadaa disfunción metabólica detectada por FibroScan

Objectives: this study aimed to explore the potential of the atherogenic index of plasma (AIP) as a predictor of metabolic dysfunction-associated fatty liver disease (MAFLD). Methods: a cross-sectional study, including data from 4473 participants in the National Health and Nutrition Examination Survey (NHANES) 2017-2018, was performed. A control attenuation parameter (CAP) ≥ 285 dB/m was used to confirm hepatic steatosis. Degrees of liver stiffness were confirmed according to liver stiffness measurement (LSM). Weighted multivariate logistic regression models were used to assess the association between AIP and the risk for MAFLD and liver fibrosis. Finally, receiver operating characteristic (ROC) curve analysis was used to test the accuracy of AIP in predicting MAFLD. Results: the association between AIP and the prevalence of MAFLD was positive in all three multivariate logistic regression models (model 1, odds ratio (OR), 18.2 (95 % confidence interval (CI), 14.4-23.1); model 2, OR, 17.0 (95 % CI, 13.3-21.8); model 3, OR, 5.2 (95 % CI, 3.9-7.0)). Moreover, this positive relationship was found to be significant in patients of different sexes and whether they had diabetes. However, no significant differences were observed between AIP and significant fibrosis or cirrhosis as assessed by different liver fibrosis indices. Finally, ROC curve analysis demonstrated that the AIP index also demonstrated positive diagnostic utility (area under the ROC curve, 0.733 (95 % CI, 0.718-0.747); p < 0.001). Conclusion: This study revealed a positive association between AIP and MAFLD among American adults. Furthermore, this association persisted in different sexes and whether they had diabetes.(AU)

Objetivos: este estudio tuvo como objetivo explorar el potencial del índice aterogénico del plasma (AIP) como predictor de enfermedad hepática grasa asociada a disfunción metabólica (MAFLD). Métodos: se realizó un estudio transversal que incluyó datos de 4473 participantes de la encuesta nacional de exémenes de salud y nutrición (NHANES) 2017-2018. Se utilizó un parámetro de atenuación de control (CAP) ≥ 285 dB/m para confirmar la esteatosis hepática. Los grados de rigidez hepática se confirmaron de acuerdo con la medición de rigidez hepática (LSM). Se utilizaron modelos de regresión logística multiva-riponderponderados para evaluar la asociación entre AIP y el riesgo de MAFLD y fibrosis hepática. Por último, se utilizó el análisis de la curva ROC para probar la precisión de la AIP en la predicción de la MAFLD.Resultados: la asociación entre AIP y prevalencia de MAFLD fue positiva en los tres modelos de regresión logística multivariable (modelo 1, odds ratio (OR): 18,2 (intervalo de confianza (IC) del 95 %: 14,4-23,1); Modelo 2, OR: 17,0 (IC del 95 %: 13,3-21,8); Modelo 3, OR: 5,2 (IC del 95 %: 3,9-7,0)). Además, esta relación positiva se encontró significativa en pacientes de diferentes sexos ya tuvieran o no diabetes. Sin embargo, no se observaron diferencias significativas entre la AIP y la fibrosis o cirrosis significativa evaluada por diferentes índices de fibrosis hepática. Finalmente, el análisis de la curva ROC demostró que el índice AIP también demostró utilidad diagnóstica positiva (área bajo la curva ROC = 0,733 (IC del 95 %: 0,718-0,747); p < 0,001). Conclusión: este estudio reveló una asociación positiva entre AIP y MAFLD en los adultos estadounidenses. Además, esta asociación persistióen los diferentes sexos ya tuvieran o no diabetes.(AU)

Point Shear Wave Elastography Detected Liver Stiffness Increased in Pediatric Patient With Thalassemia Major.

ABSTRACT: Transient elastography (TE) and point shear wave elastography (pSWE) are 2 elastographic ultrasound examinations used in liver stiffness (LS) measurement. It was shown that the LS value detected by TE in pediatric ß-thalassemia major patients has increased, and there was no LS evaluation obtained with pSWE in literature. Thus, in this study, it was aimed to evaluate LS with pSWE examination in children with thalassemia major and to determine LS-related parameters in these patients. Sixty-three schoolchildren with a diagnosis of ß-thalassemia major and 21 healthy controls between the ages of 7 and 18 years were included. In addition to routine anamnesis, physical examination, and laboratory examinations, renal and liver ultrasounds were performed. Liver stiffness values were measured by pSWE examination. Serum levels of urea, aspartate-aminotransferase, alanine-aminotransferase, iron, and ferritin were significantly higher in patients, and serum creatinine, iron binding capacity, and hemoglobin levels were found to be significantly lower (P < 0.05 for each). Liver stiffness values were significantly higher in patients compared with healthy controls. In linear regression analysis, serum iron and iron binding capacity values were found to be closely related with LS (P < 0.001 vs. ß = 0.482 and P = 0.047 vs. ß = 0.237, respectively). Liver stiffness values obtained by pSWE examination increase significantly in patients. According to the results of our study, in addition to the previously known TE method, we think that the LS evaluation obtained by pSWE, a new method that can make more accurate measurements, can be used in the possible early detection of target organ damage in children with thalassemia major.

Systematic quantification of differences in shear wave elastography estimates between linear-elastic and viscoelastic material assumptionsa).

Quantitative, accurate, and standardized metrics are important for reliable shear wave elastography (SWE)-based biomarkers. For over two decades, the linear-elastic material assumption has been employed in SWE modes. In recent years, viscoelasticity estimation methods have been adopted in a few clinical systems. The current study aims to systematically quantify differences in SWE estimates obtained using linear-elastic and viscoelastic material assumptions. An acousto-mechanical simulation framework of acoustic radiation force impulse-based SWE was created to elucidate the effect of material viscosity and shear modulus on SWE estimates. Shear modulus estimates exhibited errors up to 72% when a numerical viscoelastic phantom was assessed as linearly elastic. Shear modulus estimates of polyvinyl alcohol phantoms between rheometry and SWE following the Kelvin-Voigt viscoelastic model assumptions were not significantly different. However, the percentage difference in shear modulus estimates between rheometry and SWE using the linear-elastic assumption was 50.1%-62.1%. In ex vivo liver, the percentage difference in shear modulus estimates between linear-elastic and viscoelastic methods was 76.1%. These findings provide a direct and systematic quantification of the potential error introduced when viscoelastic tissues are imaged with SWE following the linear-elastic assumption. This work emphasizes the need to utilize viscoelasticity estimation methods for developing robust quantitative imaging biomarkers.

Ultrasound Shear Wave Elastography in Cardiology.

The advent of high-frame rate imaging in ultrasound allowed the development of shear wave elastography as a noninvasive alternative for myocardial stiffness assessment. It measures mechanical waves propagating along the cardiac wall with speeds that are related to stiffness. The use of cardiac shear wave elastography in clinical studies is increasing, but a proper understanding of the different factors that affect wave propagation is required to correctly interpret results because of the heart's thin-walled geometry and intricate material properties. The aims of this review are to give an overview of the general concepts in cardiac shear wave elastography and to discuss in depth the effects of age, hemodynamic loading, cardiac morphology, fiber architecture, contractility, viscoelasticity, and system-dependent factors on the measurements, with a focus on clinical application. It also describes how these factors should be considered during acquisition, analysis, and reporting to ensure an accurate, robust, and reproducible measurement of the shear wave.