Shear Wave Elastography Measurements Research Articles

Diagnostic Accuracy of Integrating Ultrasound and Shear Wave Elastography in Assessing Carpal Tunnel Syndrome Severity: a Prospective Observational Study.

Carpal tunnel syndrome (CTS) is a common condition characterized by compression of the median nerve (MN) within the carpal tunnel. Accurate diagnosis and assessment of CTS severity are crucial for appropriate management decisions. This study aimed to investigate the combined diagnostic utility of B-mode ultrasound (US) and shear wave elastography (SWE) for assessing the severity of CTS in comparison to electrodiagnostic tests (EDT). This prospective observational study was conducted over 9-month periods at a tertiary care hospital. A total of 48 patients (36 females, 12 males; mean age 44 ± 10.9 years; age range 28-57 years) with clinically suspected CTS were enrolled. All patients underwent EDT, US, and SWE. Based on the EDT results, CTS cases were categorized into four groups: mild, moderate, severe, and negative. The cross-sectional area (CSA) and elasticity (E) of the MN were measured at the tunnel inlet (CSAu and Eu) and pronator quadratus region (CSAo and Eo). The differences (CSAu-CSAo and Eu-Eo) were calculated. The primary outcomes were the diagnostic performance of CSAu, CSAu-CSAo, Eu, and Eu-Eo in differentiating moderate/severe from mild/negative CTS compared to EDT findings. Secondary outcomes included a correlation of US/SWE parameters with EDT grades and between each other. ANOVA, correlation, regression, and receiver operating characteristic (ROC) curve analyses were performed. CSAu and CSAu-CSAo increased progressively with worsening CTS severity. E measurements were significantly higher in moderate-to-severe CTS compared to mild or negative cases. The combined metric of CSAu-CSAo at a 5 mm threshold exhibited enhanced performance, with a higher sensitivity (83.3%), specificity (100%), and area under the curve (AUC) (0.98), surpassing the results of CSAu when used independently. Similarly, the SWE measurements indicated that Eu-Eo at a 56.1kPa cutoff achieved an AUC of 0.95, with a sensitivity of 93.3% and specificity of 94.4%, outperforming the metrics for Eu when used alone, which had an AUC of 0.93, with identical sensitivity and specificity values (93.3% and 94.4%, respectively). The integration of ultrasound, shear wave elastography, and electrodiagnostic tests provides a comprehensive approach to evaluate anatomical and neurological changes and guide management decisions for CTS.

Shear wave elastography of the breast‐histopathological comparisons

AbstractIntroductionThis study aimed to compare shear wave elastography (SWE) of benign and malignant breast lesions, evaluate the sensitivity and specificity of previously suggested thresholds for identifying malignant breast lesions, and compare SWE measures across histopathological type and grade.MethodsThis single‐centre study included 303 patients, and 405 solid breast lesions were biopsied and evaluated by mammography, which may have included contrast‐enhanced mammography, conventional B‐mode ultrasound, and SWE. Following this, elastography mean (Emean), maximum (Emax), and ratio (Eratio) variables were calculated for elasticity in kilopascals (kPa) and speed in metres per second (m/s).ResultsMalignant (n = 113) samples were significantly higher than benign (n = 267) across all SWE variables [median (interquartile range)]; Emean (kPa) [132.8 (34), vs. 41.9 (53.6), p < .001], Emean (m/s) [6.9 (1), vs. 3.7 (2.2), p < .001]. The highest combined sensitivity and specificity were for Emax (97%, 73%) at >80 kPa, and Emean (96%, 76%) at >5.2 m/s. Histopathological grade 3 (kPa), Emean [145.8 (22.5), p = .012], Emax [147.8 (19.4), p = .009], and Eratio [11.7 (6.6), p = .006] were significantly higher than grades 1 [129.2 (37.3), 133.2 (35.9), 7.53 (4.7)] and 2 [127.3 (36.4), 133.3 (34.2), 8.3 (6.1)].ConclusionBreast elastography is a sensitive complementary technique that can distinguish between malignant and benign lesions and help characterise histological profile and grade.

Shear-Wave Elastography of the Achilles tendon: reliability analysis and impact of parameters modulating elasticity values.

Shear wave elastography (SWE) has seen many advancements in Achilles tendon evaluation in recent years, yet standardization of this technique is still problematic due to the lack of knowledge regarding the optimal way to perform the examination. The purpose of this study was to evaluate the effects of ankle position, probe frequency and physical effort on the shear modulus of the Achilles tendon, but also to determine the intra and inter-observer reliability of the technique. 37 healthy volunteers were included; SWE protocol was performed by two examiners. We analyzed the shear modulus of the tendon with the ankle in neutral, maximum dorsiflexion and maximum plantar flexion using two different high frequency probes. Afterwards, the subjects performed a brief physical exercise and SWE measurements were repeated. The L18-5 probe showed the highest ICC values (ICC = 0.798, 95% CI 0.660-0.880, p < 0.001) when positioned at 2cm from the calcaneal insertion with the ankle in a neutral state. Conversely, utilizing the same L18-5 probe at 1cm from the insertion during maximum plantar flexion of the ankle resulted in the lowest ICC (ICC = 0.422, 95% CI 0.032-0.655, p = 0.019). Significant variations in elasticity values were noted among different ankle positions and probe types, while no significant changes in elasticity were observed post-physical exercise. Ankle position and probe frequency are factors that influence elasticity values of the Achilles tendon. An ankle position between 10 and 20 degrees of plantar flexion is the most suitable for SWE evaluation. However, more research focusing on Achilles tendon SWE is essential due to the challenges encountered in standardizing this region.

Effect of interstitial fluid pressure on shear wave elastography: an experimental and computational study

Objective. An elevated interstitial fluid pressure (IFP) can lead to strain-induced stiffening of poroelastic biological tissues. As shear wave elastography (SWE) measures functional tissue stiffness based on the propagation speed of acoustically induced shear waves, the shear wave velocity (SWV) can be used as an indirect measurement of the IFP. The underlying biomechanical principle for this stiffening behavior with pressurization is however not well understood, and we therefore studied how IFP affects SWV through SWE experiments and numerical modeling. Approach. For model set-up and verification, SWE experiments were performed while dynamically modulating IFP in a chicken breast. To identify the confounding factors of the SWV-IFP relationship, we manipulated the material model (linear poroelastic versus porohyperelastic), deformation assumptions (geometric linearity versus nonlinearity), and boundary conditions (constrained versus unconstrained) in a finite element model mimicking the SWE experiments. Main results. The experiments demonstrated a statistically significant positive correlation between the SWV and IFP. The model was able to reproduce a similar SWV-IFP relationship by considering an unconstrained porohyperelastic tissue. Material nonlinearity was identified as the primary factor contributing to this relationship, whereas geometric nonlinearity played a smaller role. The experiments also highlighted the importance of the dynamic nature of the pressurization procedure, as indicated by a different observed SWV-IFP for pressure buildup and relaxation, but its clinical relevance needs to be further investigated. Significance. The developed model provides an adaptable framework for SWE of poroelastic tissues and paves the way towards non-invasive measurements of IFP.

Novel high-resolution contrast agent ultrasound techniques HiFR CEUS and SR CEUS in combination with shear wave elastography, fat assessment and viscosity of liver parenchymal changes and tumors.

The continuous development of ultrasound techniques increasingly enables better description and visualization of unclear lesions. New ultrasound systems must be evaluated with regard to all these diagnostic possibilities. A multifrequency C1-7 convex probe (SC7-1M) with the new high-end system Resona A20 Series was used. Modern technologies, including HiFR CEUS, SR CEUS and multimodal tissue imaging with shear wave elastography (SWE), fat evaluation and viscosity measurements (M-Ref) were applied. Of n = 70 (mean value 48,3 years±20,3 years, range 18-84 years) cases examined, a definitive diagnosis could be made in n = 67 cases, confirmed by reference imaging and/or follow-up. Of these, n = 22 cases were malignant changes (HCC (hepatocellular carcinoma) n = 9, CCC (cholangiocellular carcinoma) n = 3, metastases of colorectal carcinomas or recurrences of HCC n = 10). In all 12 cases of HCC or CCC, the elastography measurements using the shear wave technique (with values >2 m/s to 3.7 m/s) showed mean values of 2.3±0.31 m/s and a degree of fibrosis of F2 to F4. In n = 14 cases, changes in the fat measurement (range 0.51 to 0.72 dB/cm/MHz, mean values 0.58±0.12 dB/cm/MHz) in the sense of proportional fatty changes in the liver were detected. In the 4 cases of localized fat distribution disorders, the values were >0.7 dB/cm/MHz in the sense of significant fatty deposits in the remaining liver tissue. Relevant changes in the viscosity measurements with values >1.8 kPa were found in n = 31 cases, in n = 5 cases of cystic lesions with partially sclerosing cholangitis, in n = 13 cases of malignant lesions and in n = 9 cases post-interventionally, but also in n = 4 cases of benign foci with additional systemic inflammation. The results are promising and show a new quality of ultrasound-based liver diagnostics. However, there is a need for further investigations with regard to the individual aspects, preferably on a multi-center basis.

Evaluation of common carotid artery wall stiffness by shear wave elastography in smokers and non-smokers.

Smoking is one of the most important preventable causes of cardiovascular diseases. Vascular disease caused by smoking is associated with vascular endothelial damage, platelet aggregation, and adhesion. In our study, we examined the effect of chronic smoking on vessel wall stiffness in smokers and control group by measuring carotid artery wall stiffness by shear wave ultrasonography. Sixty-two smokers of similar ages and genders, and 67 people who never smoked in the last ten years were included as the control group in this cross-sectional study. Arterial wall stiffness over the common carotid arteries of all participants was measured by shear wave elastography (SWE). In addition, each patient's blood pressure, fasting blood glucose, body mass index (BMI), HDL and LDL cholesterol measurements were recorded. Arterial wall stiffness values in smokers were found to be statistically significantly higher than in non-smokers. The mean of SWE measurements of the smokers was 47.3 ± 6.2 kPa, and that of the control group was 42.9 ± 4 kPa. The mean values of HDL and LDL of the smokers were 46.9 ± 5.6 mg/dL and 147.3 ± 9.3 mg/dL, respectively, and those of the control group were 50.3 ± 5.1 mg/dL and 136.9 ± 5.9 mg/dL. The LDL cholesterol values were statistically significantly higher in smokers compared to the control group, and HDL cholesterol values were statistically significantly lower in smokers. In our study, the arterial wall stiffness values measured by the SWE technique were higher in smokers than non-smokers.

Investigating the role of ultrasound-based shear wave elastography in kidney transplanted patients: correlation between non-invasive fibrosis detection, kidney dysfunction and biopsy results-a systematic review and meta-analysis.

Interstitial fibrosis and tubular atrophy are leading causes of renal allograft failure. Shear wave elastography could be a promising noninvasive method for providing information on the state of the kidney, with specificregard to fibrosisbut currentlyavailable data in the literature are controversial. Our study aimed to analyze the correlation between shear wave elastography and various kidney dysfunction measures. This review was registered on PROSPERO (CRD42021283152). We systematically searched three major databases (MEDLINE, Embase, and CENTRAL) for articles concerning renal transplant recipients, shear wave elastography, fibrosis, and kidney dysfunction. Meta-analytical calculations for pooled Pearson and Spearman correlation coefficients (r) were interpreted with 95% confidence intervals (CIs). Heterogeneity was tested with Cochran's Q test. I2 statistic and 95% CI were reported as a measurement of between-study heterogeneity. Study quality was assessed with the QUADAS2 tool. In total, 16 studies were included in our meta-analysis. Results showed a moderate correlation between kidney stiffness and interstitial fibrosis and tubular atrophy, graded according to BANFF classification, on biopsy findings for pooled Pearson (r = 0.48; CI: 0.20, 0.69; I2 = 84%) and Spearman correlations (r = 0.57; CI: 0.35, 0.72; I2 = 74%). When compared to kidney dysfunction parameters, we found a moderate correlation between shear wave elastography and resistive index (r = 0.34 CI: 0.13, 0.51; I2 = 67%) and between shear wave elastography and estimated Glomerular Filtration Rate (eGFR) (r = -0.65; CI: -0.81, -0.40; I2 = 73%). All our outcomes had marked heterogeneity. Our results showed a moderate correlation between kidney stiffness measured by shear wave elastography and biopsy results. While noninvasive assessment of kidney fibrosis after transplantation is an important clinical goal,there is insufficient evidence to support the use ofelastography overthe performance of a kidney biopsy.

Erken Evre Karaciğer Fibrozisini Öngörmede Shear Wave Elastografinin Rolü

Aim: We examined the relationship between shear wave elastography (SWE) values and histopathological results in our study. Thus, we found the sensitivity of SWE in demonstrating early fibrosis. Materials and Methods: A total of consecutive 70 patients with chronic hepatitis B were prospectively evaluated. The patients included in fibrosis stages (F) 0, 1, 2, 3 and 4 according to Ishak scoring were examined with SWE. SWE measurements of F2, F3 and F4 patients who were found to have early stage fibrosis were compared with those of F0 and F1 patients. Results: The velocity+SD, and kPa+SD values in the group requiring treatment (F2, F3 and F4) were significantly higher than the group not requiring treatment (F0 and F1 )(p &amp;lt; 0.05). The sensitivity rate of the 1.85 cut-off value for velocity+SD was 53.8%, the positive prediction rate was 80.8%, the specificity rate was 83.3%, and the negative prediction rate was 58.1%. For kPa+SD, the cut-off value of 10.8 had a sensitivity rate of 51.3%, a positive prediction rate of 95.2%, a specificity of 96.7%, and a negative predictive rate of 60.4%. A significant correlation was observed between the fibrosis score and the kPa+SD distribution. Conclusion: SWE can differentiate the patients requiring treatment (F2, F3 and F4) from the patients not requiring treatment.

Optical coherence tomography and shear wave elastography findings in Graves ophthalmopathy.

The main feature of Graves ophthalmopathy (GO) is revealed by determining the activity and severity of the disease. We aimed to evaluate the use of imaging methods can also provide additional information about the severity of this disease. Optical coherence tomography (OCT) and shear wave elastography (SWE) findings were compared in 32 patients with mild GO group and in the healthy control group. Measuring for TSH receptor antibody (TRAb) serum level is used third-generation assay. In Graves group, optic nerve sheath diameter (ONSD) values were increased in both eyes (p < 0.001, p < 0.001). SWE measurements showed a significant increase both eye optic nerve (ON) and right eye soft tissue elasticity values in GO group (p < 0.001, p < 0.001, p < 0.001, respectively). There was a significant thinning in left temporal retinal nerve fiber layer (RNFL) thickness and left RNFL peripapillary thickness in GO group (p < 0.001, p < 0.025, respectively). There was a correlation between left eye OCT and SWE findings. Also, there was a significant difference between the median left eye ON and soft tissue elasticity results in the TRAb-positive GO group (p = 0.049, p = 0.048, respectively). SWE measurements showed a significant increase both eyes ONSD, ON and right eye soft tissue elasticity values in GO group. GO group was significant thinning in some left eye regions in OCT measurements. There was a correlation between left eye OCT and SWE findings. In addition to clinical activity score and TRAb, SWE and OCT can be used to monitor in patients with GO.

Suboptimal reliability of FIB-4 and NAFLD-fibrosis scores for staging of liver fibrosis in general population.

The burden and incidence of liver cirrhosis are increasing worldwide. Early detection of liver fibrosis would help in early interventions and preventing the progression of fibrosis and cirrhosis. The accepted noninvasive markers for liver fibrosis staging, namely fibrosis-4 (FIB-4) and nonalcoholic fatty liver disease fibrosis score (NFS), have shown inconsistent performance for detecting the fibrosis stage. We aimed to evaluate the efficacy of FIB-4 score and NFS for the detection of liver fibrosis in the general population. From a general population referred from a single, community-based family-physician clinic, we included study participants between the ages of 45 and 65 years, with no knowledge of liver disease and no record of alcohol consumption. Liver fibrosis was evaluated by the FIB-4 score and NFS using shear wave elastography (SWE) or transient elastography (TE) measurements as a reference. A total of 76 participants (aged 61.5 ± 0.37 years, 33% females) were included in the study cohort. We observed a nonsignificant correlation between liver stiffness measurement (LSM) and FIB-4 and NFS (r = 0.1, P = 0.37; r = 0.16, P = 0.15, respectively). Our results showed that only 5.2% with FIB-4 >3.25 and 9.7% with NFS >0.675 had LSM >12 kPa. The compatibility of fibrosis staging was 55% between FIB-4 score and LSM and only 18% between NFS and LSM. We found that FIB-4 and NFS are unreliable tools for liver fibrosis estimation in the general population. There is a need for more reliable noninvasive methods for the early detection of liver fibrosis.

Differences in Achilles tendon mechanical properties between professional ballet dancers and collegiate athletes utilizing shear wave elastography.

To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

Diagnostic value of shear-wave elastography for patellar tendinopathy in female volleyball and basketball athletes: a cross sectional case control study

ABSTRACT Objectives We aim to investigate the accuracy of shear-wave elastography (SWE) in diagnosing patellar tendinopathy in female volleyball and basketball players. In addition, we compared different parts of the patellar tendon and investigated the effects of different knee angles on elastography measurements. Methods This cross-sectional case–control study evaluated 63 female athletes from professional basketball and volleyball teams (NCT06199583). Patellar tendinopathy diagnoses were made using clinical and ultrasonographic criteria. SWE measurements were taken at 30-degree knee flexion and extension. Rectangular regions of interest boxes were placed in three different parts of the tendon (proximal, middle, distal). The global SWE value was calculated by taking the mean of measurements in the three parts. Receiver operating characteristic (ROC) curves were used to identify significant cutoff points for SWE, and 2 × 2 tables were generated to determine sensitivity and specificity. Results Thirteen (20.6%) of the 63 athletes were diagnosed with patellar tendinopathy. The ROC curves have identified different cutoff scores for SWE measurements. The SWE score of 130.75 from the proximal part showed the highest sensitivity of 89% and specificity of 80% (p < 0.001) with a 4.45 likelihood ratio at the 30-degree knee flexion. The likelihood ratio is 1.5 at a 30-degree angle and 1.65 at a 0-degree angle when measuring the entire tendon, whereas other portions indicate a ratio ranging from 1.12 to 1.73. Conclusions Shear-wave elastography is a reliable evaluation method for diagnosing patellar tendinopathy. It has more accuracy when applied to the proximal part and at 30-degree knee flexion compared to measurements taken at knee extension and other parts of the tendon.

P289 Bowel Stiffness Assessed by Shear-wave Ultrasound Elastography Predicts Disease Behavior Progression in Patients with Crohn’s Disease

Abstract Background There is a lack of reliable predictors of disease behavior progression in patients with Crohn’s disease (CD). Real-time shear-wave elastography (SWE), a novel method for evaluating tissue stiffness, is reportedly helpful in determining the prognosis of liver cirrhosis or breast cancer. However, its value for assessing CD has not yet been investigated. We aimed to explore the value of SWE and other ultrasound parameters at diagnosis in predicting CD behavior progression. Methods We retrospectively collected data from CD patients with the non-stenotic non-penetrating disease (B1 phenotype based on the Montreal classification). All patients underwent intestinal ultrasound with SWE measurement at baseline and were followed up. The endpoint was defined as disease behavior progression to stricturing (B2) or penetrating (B3) disease. A multivariate Cox regression model was used to explore the association between baseline SWE and subsequent outcome. We also established a multivariate nomogram to predict the risk of disease behavior progression and evaluated its performance with receiver operating characteristic curve and decision curve analysis. Results A total of 130 CD patients with B1 phenotype were enrolled. Twenty-seven patients (20.8%) developed B2 or B3 disease, with a median follow-up of 33 months. Multivariate analysis identified that SWE ≥12.75 kPa was the only independent predictor of disease behavior progression (HR 1.08, 95% CI 1.03-1.12, P=0.001, Fig 1A). A restricted cubic spline with multiple covariates adjusted showed an approximately linear positive correlation between SWE and the risk of disease behavior progression, with a cut-off of 12.75 kPa (Fig 1B). We further established a multivariate nomogram incorporating SWE and other clinical characteristics to predict the risk of disease behavior progression quantitatively (Fig 1C). Compared to the model composed solely of SWE, the multivariate nomogram showed a higher but less significant performance (0.738 vs. 0.792, p=0.169, Fig 1D). However, the decision curve analysis showed that the model outperformed the single indicator of SWE in predicting endpoint events, especially those occured after 12 months of baseline (Fig 1E). Conclusion Intestinal stiffness assessed using SWE is an independent predictor of disease behavior progression in patients with CD. CD patients with SWE ≥12.75 kPa at diagnosis are prone to progress toward stricturing or penetrating diseases, which warrants timely intervention.

Ultrasound in the Diagnosis of Non-Expandable Lung: A Prospective Observational Study of M-Mode, B-Mode, and 2D-Shear Wave Elastography.

Non-expandable lung (NEL) has severe implications for patient symptoms and impaired lung function, as well as crucial implications for the management of malignant pleural effusion (MPE). Indwelling pleural catheters have shown good symptom relief for patients with NEL; hence, identifying patients early in their disease is vital. With the inability of the lung to achieve pleural apposition following thoracentesis and the formation of a hydropneumothorax, traditionally, chest X-ray and clinical symptoms have been used to make the diagnosis following thoracentesis. It is our aim to investigate whether ultrasound measurement of lung movement during respiration can predict NEL before thoracentesis, thereby aiding clinicians in their planning for the optimal treatment of affected patients. A total of 49 patients were consecutively included in a single-centre trial performed at a pleural clinic. Patients underwent protocolled ultrasound assessment pre-thoracentesis with measurements of lung and diaphragm movement and shear wave elastography measurements of the pleura and pleural effusion at the planned site of thoracentesis. M-mode measurements of lung movement provided the best diagnostic ROC-curve results, with an AUC of 0.81. Internal validity showed good results utilising the calibration belt test and Brier test. M-mode measurement of lung movement shows promise in diagnosing NEL before thoracentesis in patients with known or suspected MPE. A validation cohort is needed to confirm the results.

Shear wave elastography: A noninvasive approach for assessing acute kidney injury in critically ill patients.

Traditional markers, such as serum creatinine and blood urea nitrogen, frequently show delayed elevations following acute kidney injury (AKI), limiting their utility for prompt detection and timely intervention in AKI management. Shear wave elastography (SWE) exhibits potential for AKI diagnosis by measuring tissue stiffness. Our study aimed to evaluate the diagnostic performance of SWE in detecting AKI by measuring the stiffness of kidney tissue. Between July 2022 and December 2022, a total of 103 consecutive participants who met the eligibility criteria were prospectively enrolled, underwent SWE measurements, and were classified into AKI or non-AKI groups based on the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) criteria. A receiver operating characteristic (ROC) curve was drawn to examine the feasibility of differentiating between AKI and non-AKI patients and assessing diagnostic performance. The effects of tissue anisotropy on SWE measurements were also examined. Our results revealed that patients in the AKI group exhibited significantly increased stiffness values in specific kidney regions compared with those in the non-AKI group. For the diagnosis of AKI, the optimal cut-off values were identified as 9.9 kPa, 2.9 kPa, and 4.4 kPa for the upper pole medulla, middle cortex, and middle medulla, respectively, in the longitudinal plane. Correspondingly, the areas under the ROC curves for these regions were 0.737 (95% confidence interval [CI]: 0.637, 0.822), 0.736 (95% CI: 0.637, 0.821), and 0.784 (95% CI: 0.688, 0.861). Additionally, we observed a significant variability in stiffness values due to tissue anisotropy, specifically in the segments of the upper pole cortex, and medulla across both longitudinal and transverse planes. SWE serves as a noninvasive approach for the quantification of tissue stiffness and shows promise as an adjunctive tool for the assessment of AKI.

Is musculoskeletal pain associated with increased muscle stiffness? Evidence map and critical appraisal of muscle measurements using shear wave elastography.

Approximately 21% of the world's population suffers from musculoskeletal conditions, often associated with sensations of stiff muscles. Targeted therapy requires knowing whether typically involved muscles are objectively stiffer compared to asymptomatic individuals. Muscle stiffness is quantified using ultrasound shear wave elastography (SWE). Publications on SWE-based comparisons of muscle stiffness between individuals with and without musculoskeletal pain are increasing rapidly. This work reviewed and mapped the existing evidence regarding objectively measured muscle stiffness in musculoskeletal pain conditionsand surveyed current methods of applying SWE to measure muscle stiffness. A systematic search was conducted in PubMed and CINAHL using the keywords "muscle stiffness","shear wave elastography","pain","asymptomatic controls" and synonyms. The search was supplemented by a hand search using Google Scholar. Included articles were critically appraised with the AXIS tool, supplemented by items related to SWE methods. Results were visually mapped and narratively described. Thirty of 137 identified articles were included. High-quality evidence was missing. The results comprise studies reporting lower stiffness in symptomatic participants, no differences between groupsand higher stiffness in symptomatic individuals. Results differed between pain conditions and muscles, and also between studies that examined the same muscle(s) and pathology. The methods of the application of SWE were inconsistent and the reporting was often incomplete. Existing evidence regarding the objective stiffness of muscles in musculoskeletal pain conditions is conflicting. Methodological differences may explain most of the inconsistencies between findings. Methodological standards for SWE measurements of muscles are urgently required.

Influence of the physical pressure of an ultrasound probe on shear-wave elastography measurements of the gastrocnemius muscle in a paediatric population: a non-interventional cohort study.

The aim of our study is to evaluate the impact of ultrasound probe mechanical pressure on the stiffness of the gastrocnemius muscle in a healthy paediatric population. As far as we know, there has been no previous qualitative in vivo study on the impact of probe pressure on muscle shear-wave elastography results with objective evaluation of compression in the paediatric population. In this cohort study, a group of 22 children (mean age 8.99 years, SD 2.74, 11 males) underwent elastography of the gastrocnemius muscle of the dominant leg. A custom-made, 3-dimensional printed probe cover was used to measure the mechanical pressure of the probe on tissues. The obtained results were related to the age, sex, BMI, and calf circumference of the subjects. We observed a significant difference in the stiffness parameter at a pressure of 1 N, with a further increase if force was increased (p < 0.001). A significant, very weak positive correlation of age and stiffness was observed (p < 0.001, r2 = 0.022). There was no significant correlation of stiffness, BMI, and calf circumference. The use of compression during muscle elastography in children causes a significant bias in results, regardless of age, sex, BMI, or calf size.

Three-dimensional mapping of ultrasound-derived skeletal muscle shear wave velocity.

Introduction: The mechanical properties of skeletal muscle are indicative of its capacity to perform physical work, state of disease, or risk of injury. Ultrasound shear wave elastography conducts a quantitative analysis of a tissue's shear stiffness, but current implementations only provide two-dimensional measurements with limited spatial extent. We propose and assess a framework to overcome this inherent limitation by acquiring numerous and contiguous measurements while tracking the probe position to create a volumetric scan of the muscle. This volume reconstruction is then mapped into a parameterized representation in reference to geometric and anatomical properties of the muscle. Such an approach allows to quantify regional differences in muscle stiffness to be identified across the entire muscle volume assessed, which could be linked to functional implications. Methods: We performed shear wave elastography measurements on the vastus lateralis (VL) and the biceps femoris long head (BFlh) muscle of 16 healthy volunteers. We assessed test-retest reliability, explored the potential of the proposed framework in aggregating measurements of multiple subjects, and studied the acute effects of muscular contraction on the regional shear wave velocity post-measured at rest. Results: The proposed approach yielded moderate to good reliability (ICC between 0.578 and 0.801). Aggregation of multiple subject measurements revealed considerable but consistent regional variations in shear wave velocity. As a result of muscle contraction, the shear wave velocity was elevated in various regions of the muscle; showing pre-to-post regional differences for the radial assessement of VL and longitudinally for BFlh. Post-contraction shear wave velocity was associated with maximum eccentric hamstring strength produced during six Nordic hamstring exercise repetitions. Discussion and Conclusion: The presented approach provides reliable, spatially resolved representations of skeletal muscle shear wave velocity and is capable of detecting changes in three-dimensional shear wave velocity patterns, such as those induced by muscle contraction. The observed systematic inter-subject variations in shear wave velocity throughout skeletal muscle additionally underline the necessity of accurate spatial referencing of measurements. Short high-effort exercise bouts increase muscle shear wave velocity. Further studies should investigate the potential of shear wave elastography in predicting the muscle's capacity to perform work.

Application of Ultrasound Shear Wave Elastography Combined With BRAFV600E Mutation for the Diagnosis of Papillary Thyroid Carcinoma.

This prospective study aimed to investigate the combination of shear wave elastography (SWE) and BRAFV600E mutation testing for the diagnosis of papillary thyroid carcinoma (PTC). One hundred thyroid nodules with an American College of Radiology thyroid imaging reporting and data system classification of 4 or 5 were subjected to SWE measurement, BRAFV600E genotyping, fine-needle aspiration, and surgery. Nonparametric statistical tests were used to compare the differences in the elastic parameters and BRAF genotypes between benign and malignant thyroid nodules of PTC, and receiver operating characteristic curve analysis was conducted to compare the diagnostic efficacy. In addition, the correlations between elastic parameters and BRAFV600E mutation in PTC were analyzed using binary logistic regression. The SWE, BRAFV600E, and their combination exhibited sensitivities of 72.9%, 81.3%, and 85.4%, respectively, and specificities of 66.7%, 90.3%, and 86.5%, respectively, in the diagnosis of PTC ( P < 0.05). The SWE, BRAFV600E, and their combination exhibited sensitivities of 50.0%, 24.1% and 56.3%, respectively, and specificities of 89.7%, 87.5% and 82.8%, respectively, in the diagnosis of central cervical lymph node metastasis ( P < 0.05). The combined use of SWE and BRAFV600E detection had the largest area under the curve, indicating that this combination is more effective in diagnosing PTC and lymph node metastasis in the central region than either method alone. Furthermore, Emax was positively associated with the BRAFV600E genotype. In conclusion, the combination of SWE and BRAFV600E genotype detection can improve the diagnostic efficacy for PTC. Emax can predict the BRAFV600E mutation status.

Non-invasive evaluation of testicular torsion using ultrasound shear wave elastography: an experimental study.

The goal of this study was to examine changes in testicular stiffness at various intervals after the induction of testicular torsion, as well as to assess the predictive value of testicular stiffness for testicular spermatogenesis after torsion. Sixty healthy male rabbits were randomly assigned to one of three groups: complete testicular torsion, incomplete testicular torsion, or control. All rabbits underwent preoperative and postoperative scrotal ultrasonography, including shear wave elastography (SWE), at predetermined intervals. Changes in SWE values were analyzed and compared using repeatedmeasures analysis of variance. To assess the diagnostic performance of SWE in determining the degree of spermatogenic function impairment, the areas under the receiver operating characteristic curves (AUCs) were calculated. SWE measurements in both central and peripheral zones of the testicular parenchyma affected by torsion demonstrated significant negative correlations with spermatogenesis, with coefficients of r=-0.759 (P<0.001) and r=-0.696 (P<0.001), respectively. The AUCs of SWE measurements in the central or peripheral zones of the torsed testicular parenchyma were 0.886 (sensitivity, 83.3%; specificity, 100%) and 0.824 (sensitivity, 83.3%; specificity, 73.3%) for distinguishing between hypospermatogenesis and spermatogenic arrest, respectively (P=0.451, DeLong test). Variations in the stiffness of both central and peripheral regions of the testicular parenchyma correlate with the extent and duration of torsion, exhibiting a specific pattern. The "stiff ring sign" is the characteristic SWE finding associated with testicular torsion. SWE appears to aid in the non-invasive determination of the extent of spermatogenic damage in torsed testes.