Attenuation Measuring Ultrasound Shearwave Elastography (AMUSE) as Noninvasive Imaging Biomarker for Liver Acute Cellular Rejection.

OBJECTIVE: There are over 9000 liver transplants in the United States per year, with acute cellular rejection (ACR) being a prevalent early post-transplant complication (20%-40%) treated using corticosteroids. Ischemia-reperfusion injury (IRI), another early post-transplant pathology, has similar laboratory results but typically resolves without therapy. ACR confirmation requires invasive liver biopsy, bearing risks like hemorrhage and pneumothorax. Attenuation Measuring Ultrasound Shearwave Elastography (AMUSE) assesses shear wave velocity (c) and attenuation (α) without rheological models and have shown potential for noninvasive tissue characterization. METHODS: We analyzed 58 transplanted livers suspected for ACR by comparing AMUSE measurements to biopsy findings. Thirteen patients underwent longitudinal tracking from ACR diagnosis on day 7 to therapy initiation and repeat biopsy on day 14. Statistical methods and support vector machine (SVM) were used for performance analysis. RESULTS: AMUSE measurements at 100, 200, and 300 Hz showed statistical significance (p < 0.001) for ACR presence, with 200 Hz exhibiting the highest Spearman correlation coefficients for c and α (0.68 and -0.83). High c (> 2.2 m/s) and low α (< 130 Np/m) at 200 Hz correlated with ACR diagnostic, while low c and high α indicated no ACR. Combining c and α into a single biomarker α/c improved patient differentiation, yielding an F1-score of 0.97. SVM was used to evaluate AMUSE ACR staging capabilities using all available frequencies, reaching 0.95 F1-score for categorical classification, with an AUROC of 0.99. When evaluating the presence of ACR the SVM reached 0.99 F1-score, with 1.00 sensitivity/recall. CONCLUSION: These findings support the use of AMUSE potential for detection and staging of liver ACR.

Ultrasound Shear Wave Elastography of the Arch-Supporting Structures in Symptomatic Flatfoot: A Pilot Study.

Background: The posterior tibial tendon (PTT), deltoid ligament, and spring ligament are often torn or attenuated in patients with progressive collapsing foot deformity. The goal of this pilot study was to measure the ultrasound shear wave velocity (SWV) of these arch-supporting structures in feet with varying degrees of deformity to improve our understanding of their role in the progression of deformity. Methods: Two observers measured the SWV of the supramalleolar and inframalleolar PTT in long and short axes, in the tibiospring portion of the deltoid ligament, and in the superomedial band of the spring ligament in 8 neutrally aligned feet, 5 asymptomatic flatfeet, and 7 symptomatic flatfeet. Each measurement was repeated 3 times both with and without an applied eversion stress. Results: Average SWV was lower at all locations in the symptomatic flatfeet compared with normal feet, but these differences were statistically significant only for the inframalleolar PTT and the spring ligament. Externally applied stress led to an increase in the SWV of the ligaments but a paradoxical decrease in the SWV in the supramalleolar PTT. The SWV of the PTT was lower along the short axis compared with the long axis. Conclusion: SWV may be useful in evaluating the severity of degenerative disease of arch-supporting structures, but further study is needed before this technique can be applied clinically. Level of Evidence: Level III, case-control study.

Seismic site characterization baseline data for microzonation and site response analysis of Otuasega Town, Bayelsa State, Niger Delta region of Nigeria.

This study presents the findings of a comprehensive geotechnical and seismic site investigation conducted at Otuasega Town located in Bayelsa State within the Niger Delta region of Nigeria. Subsurface exploration involved advancing 10 boreholes to 30 m depth using hollow stem auger drilling. Continuous disturbed and undisturbed soil sampling was performed at 1.5 m intervals for detailed geotechnical testing. Laboratory tests on the recovered soil samples established the index properties, classification, densities and consistency limits of the stratified deposits. The subsurface profile comprised alternating layers of clay, silt and sand typical of deltaic sediments, with the clay fractions exhibiting medium to high plasticity. Shear wave velocity (Vs) profiling using Multichannel Analysis of Surface Waves (WASW) techniques categorised the site predominantly as Site Class C and D based on international standards. The Standard Penetration Test (SPT) N-values ranged from 5 to 10, indicating soft normally consolidated clay conditions typical of the Niger Delta region. Predictive empirical models developed from the field and lab data showed strong correlations for estimating key geotechnical parameters such as SPT blow count, Vs and liquefaction resistance. Ground response analyses using the Vs and SPT data indicated significant site amplification potential, with peak ground accelerations up to 1.5 times the bedrock motion. Liquefaction analysis based on the empirical SPT-based methods revealed a high potential for liquefaction in the sandy layers, especially under strong earthquake shaking. The study characterized the complex sedimentology and provided baseline information for seismic microzonation and site-specific ground response analyses to advance understanding of geohazards in this delta environment.

Comprehensive geophysical, geotechnical, and geochemical assessments of an offshore landfill in Singapore.

Comprehensive site investigation techniques, including Electrical Resistivity Tomography (ERT), Induced Polarization (IP), Multichannel Analysis of Surface Waves (MASW), and Microtremor Array Method (MAM), were integrated with geotechnical and geochemical tests of retrieved waste samples from Singapore's operational offshore landfill. The properties of landfill wastes vary widely, including shear-wave velocities 127-248 m/s, densities 1.2-2.1 Mg/m3, resistivity 3.0-25.3 Ω∙m, and chargeability 48-82 mV/V. The natural clay layer underneath was clearly delineated and effectively mitigated leachate leakage. K-means clustering of the geophysical data facilitates precise mapping of waste distribution and quantities of recoverable metals based on quantitative criteria. This study illustrates a thorough case study adopting the new site investigation and characterization paradigm for an offshore landfill, which provides insights into leachate leakage detection and evaluations of landfill mining and resource recovery.

Inversion method of NHV based on novel model parameter space acquisition strategy and its application in the Tonghai basin site in Yunnan, China.

The imaging of subsurface soil velocity structures from ambient noise inversion is a difficult problem. Few recording points and a simplified 1-D layered profile lead to important non-uniqueness. From our point of view, improving the reliability of processing methods of the observed data to obtain noise horizontal-to-vertical spectral ratio (NHV) curves and setting a complete model parameter space are important tasks to reduce the non-uniqueness of inversion. In this study, using a local site near the border of the Tonghai Basin, China, as a case study, we first demonstrate how to identify and mitigate the influence of industrial sources using surface observations to obtain more reliable NHV curves. Then, a new strategy to determine model parameter space is proposed, that is, stratifying soil layers based on the number of NHV peaks and determining the shear wave velocities, thicknesses, and their ranges based on the empirical relationship between sedimentary thickness and resonant frequency (h-f r). Subsequently, combining the model parameter space acquisition strategy with the NHV inversion, a novel NHV inversion approach is developed and applied to obtain the 2-D V S profile of the investigated Tonghai site. The inverted 2-D V S profile aligns favorably with the frequency-depth conversion results of the measured NHV curves (NHV-profiling) and the measured borehole profiles, affirming the reliability of the proposed NHV inversion method. Finally, by comparing the empirical transfer functions from the strong-motion recordings, we validated the applicability of the inverted models for characterizing site effects. The model parameter space acquisition strategy proposed in this paper and the analysis procedure of the observed data are also applicable to other study areas, which can provide a referable approach to quickly and effectively acquire the soil layer velocity structure of the site.

The impact of a 10-week Nordic hamstring exercise programme on hamstring muscle stiffness, a randomised controlled trial using shear wave elastography.

Hamstring strain injuries (HSIs) remain a burden with high prevalence rates. The Nordic Hamstring exercise (NHE) has been found to be effective in preventing HSIs. However, the preventive mechanisms are not fully understood. Changes in stiffness are postulated as a possible protective mechanism. Surprisingly, the effect of the NHE on the stiffness of different hamstring muscles has never been investigated before. Therefore, the aim of this Randomised controlled trial was to investigate the impact of a 10-week NHE programme on the eccentric strength and the shear wave velocity (proxy of stiffness) of the hamstrings. Thirty-six soccer players were randomly assigned to either the control or the experimental group. The experimental protocol consisted of the incorporation of a 10-week NHE programme within the normal training routine. The hamstring stiffness and eccentric strength were assessed before and after. Within-group analyses showed a significant increase in strength, only for the experimental group. However, no significant effect of the NHE was found on the stiffness of each hamstring muscle. A 10-week NHE programme does not affect hamstring stiffness, despite an increase in eccentric strength, indicating that the preventive mechanism of the NHE is probably not (co-)explained by alterations in hamstring muscle stiffness.

The Relationship between Placental Shear Wave Elastography and Fetal Weight-A Prospective Study.

Background/Objectives: The utility of shear wave elastography (SWE) as an adjunct to ultrasound biometry and Doppler velocimetry for the examination of placental dysfunction and suboptimal fetal growth is unclear. To date, limited data exist correlating the mechanical properties of placentae with fetal growth. This study aimed to investigate the relationship between placental shear wave velocity (SWV) and ultrasound estimated fetal weight (EFW), and to ascertain if placental SWV is a suitable proxy measure of placental function in the surveillance of small-for-gestational-age (SGA) pregnancies. Methods: This prospective, observational cohort study compared the difference in placental SWV between SGA and appropriate-for-gestational-age (AGA) pregnancies. There were 221 women with singleton pregnancies in the study cohort-136 (61.5%) AGA and 85 (38.5%) SGA. Fetal biometry, Doppler velocimetry, the deepest vertical pocket of amniotic fluid, and mean SWV were measured at 2-4-weekly intervals from recruitment to birth. Results: There was no difference in mean placental SWV in SGA pregnancies compared to AGA pregnancies, nor was there any relationship to EFW. Conclusions: Although other studies have shown some correlation between increased placental stiffness and SGA pregnancies, our investigation did not support this. The mechanical properties of placental tissue in SGA pregnancies do not result in placental SWVs that are apparently different from those of AGA controls. As this study did not differentiate between constitutionally or pathologically small fetuses, further studies in growth-restricted cohorts would be of benefit.

Performance of salivary glands ultrasonography, shear wave elastography and their combined use for the diagnosis of primary and secondary Sjögren's syndrome.

BACKGROUND: Sjögren's syndrome (SS) is a common rheumatic disease for which finding the right imaging tool remains a challenge. PURPOSE: This study aimed to evaluate the performance of salivary gland ultrasonography (SGUS), shear wave elastography (SWE) and their combined use for the diagnosis of primary and secondary SS (pSS and sSS). METHODS: This retrospective study included patients with dry symptoms who underwent routine examinations between May 2019 and December 2023. Patients were categorized into the pSS (n = 41), sSS (n = 26), and control (n = 27) groups based on the American College of Rheumatology/European League Against Rheumatism classification criteria (2016). A comparison of SGUS and shear wave velocity (SWV) results was conducted among the three groups. The diagnostic capabilities of different ultrasound methods for SS were evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC) for specificity. RESULTS: Compared to the control group, both the pSS (1.80 ± 1.03 vs. 0.67 ± 0.48, p < 0.001) and the sSS (1.85 ± 0.88 vs. 0.67 ± 0.48, p < 0.001) groups exhibited significantly elevated SGUS scores. However, there was no statistically significant difference between the pSS and sSS groups (p = 0.849). The SWV values in both the pSS and sSS groups were significantly higher than those in the control group (all p < 0.001). The AUC for diagnosing SS using only SGUS scores was 0.823 (95% confidence interval [CI]: 0.731-0.894). Combining SGUS scores and SWV values resulted in improved diagnostic accuracy (AUC: 0.883, 95% CI: 0.801-0.940). CONCLUSIONS: SGUS and SWE are pivotal in the diagnosis of Sjögren's syndrome, with their synergistic application poised to bolster diagnostic precision. This combined approach also furnishes substantial backing for the clinical assessment and management of Sjögren's syndrome.

Diagnostic efficiency of conventional ultrasound, shear wave elastography, and superb microvascular imaging in evaluating ulnar neuropathy at the elbow.

INTRODUCTION/AIMS: The current diagnosis of ulnar neuropathy at the elbow (UNE) relies mainly on the clinical presentation and nerve electrodiagnostic (EDX) testing, which can be uncomfortable and yield false negatives. The aim of this study was to investigate the diagnostic value of conventional ultrasound, shear wave elastography (SWE), and superb microvascular imaging (SMI) in diagnosing UNE. METHODS: We enrolled 40 patients (48 elbows) with UNE and 48 healthy volunteers (48 elbows). The patients were categorized as having mild, moderate or severe UNE based on the findings of EDX testing. The cross-sectional area (CSA) was measured using conventional ultrasound. Ulnar nerve (UN) shear wave velocity (SWV) and SMI were performed in a longitudinal plane. RESULTS: Based on the EDX findings, UNE severity was graded as mild in 4, moderate in 10, and severe in 34. The patient group showed increased ulnar nerve CSA and stiffness at the site of maximal enlargement (CSA mean at the site of max enlargement [CSAmax] and SWV mean at the site of max enlargement [SWVmax]), ulnar nerve CSA ratio, and stiffness ratio (elbow-to-upper arm), compared with the control group (p < .001). Furthermore, the severe UNE group showed higher ulnar nerve CSAmax and SWVmax compared with the mild and moderate UNE groups (p < .001). The cutoff values for diagnosis of UNE were 9.5 mm2 for CSAmax, 3.06 m/s for SWVmax, 2.00 for CSA ratio, 1.36 for stiffness ratio, and grade 1 for SMI. DISCUSSION: Our findings suggest that SWE and SMI are valuable diagnostic tools for the diagnosis and assessment of severity of UNE.

Comparison of Testicular Sonography and Elastography Findings With Semen Parameters in Cases Investigated for Infertility.

OBJECTIVES: This study aimed to investigate the correlation between testicular shear wave elastography (SWE) values and semen analysis results in men with infertility. METHODS: This was a retrospective case-control study. Patients were categorized as normal, abnormal, or azoospermic based on sperm analysis results. Testicular volume was measured using B-mode ultrasonography using the Lambert formula. Subsequently, 40-80 regions of interest measuring 1.5 × 1.5 mm were manually positioned in both testicles based on their size, and two-dimensional SWE was applied through virtual touch imaging quantification software. RESULTS: The patients had a mean age of 33.79 ± 6.3 years, with semen analysis revealing normal results in 15 patients (22.4%), pathological findings in 35 patients (52.2%), and azoospermia in 17 patients (25.4%). Right, left, total, and mean testicular volumes were significantly lower in patients with azoospermia compared to those in both normal and impaired semen parameters (P < .05). Conversely, testicular elastography scores were higher in patients with azoospermia than in the other groups (P < .05). The significant negative correlation between volume and elastographic findings remained independent of age (r = 0.4, P < .001). The accuracy rates for detecting impaired semen parameters and azoospermia were 94.3% and 94.1%, respectively, after considering factors such as age, testicular volume (right/left/total), and elastography (right/left/total). Notably, the total mean elastography score ranked first, with 100% in the independent normalized importance distribution of these variables. CONCLUSION: SWE can be used effectively alone or in combination with other diagnostic tools to evaluate histopathological changes in the testicles of male patients with infertility.

Sub-surface shear wave velocity models developed based on a combined in-situ measurement of quasi-static cone penetration test (q-CPT) and microtremor datasets.

A representative sub-surface shear wave velocity model is crucial for seismic hazard studies, as seismic waves are affected by sub-surface characteristics. The offered data in this article were mainly developed based on a quasi-static cone penetration test (q-CPT) collected at the west coast town of Aceh, Indonesia. Microtremor datasets measured at the same locations were employed to extend the depth of the sub-surface models and to validate the models. The in-situ q-CPT data were collected using a locally manufactured Begemann's type cone penetration test apparatus. Twenty seven (27) q-CPT soundings were performed to typical depths of 20 m or measuring cone tip resistances of at least 150 kg/cm2. Several empirical approaches were employed to deduce the sub-surface parameters, including shear wave velocity. To enhance the sub-surface model depth, 23 in-situ microtremor data were recorded using 3 components (3C) of Geobit S100 and RaspberrySHAKE (RS-3D) seismometers at the same locations where the q-CPTs were sounded. At the same time, these microtremor datasets were also utilized to validate the developed sub-surface shear wave velocity models using the forward modeling method. Therefore, all the proposed sub-surface shear wave models presented in this article have been validated. These sub-surface shear wave velocity models can be used for site characterization, i.e., site response analysis, seismic microzonation, or spatial urban planning.

Effectiveness of High-Power Laser Therapy via Shear Wave Speed Analysis on Pain and Functioning in Patients with Lateral Epicondylitis: A Proof-of-Concept Study.

Background: Lateral epicondylitis (LE) causes lateral elbow pain due to the overuse of the common extensor tendon. Several therapies have been proposed for pain relief and functional recovery, including physical therapy, minimally invasive injection approaches, and physical agent modalities such as laser therapy. Methods: Our study evaluates the impact of high-power laser therapy (HPLT) on pain and functioning. The HPLT protocol consists of 10 daily sessions using a LASERIX PRO device. The healthy elbow of each participant was also considered as a control group. The outcomes assessed were the Numerical Rating Scale (NRS) for pain, QuickDASH questionnaire for functionality, and shear wave velocity (SWS) through ultrasonography. Assessments were conducted at baseline (T0), post-treatment (T1), and 2-week follow-up (T2). Results: Sixteen participants (81.2% male, mean age 40.4 ± 5.53 years) completed the study. Post-treatment, pain significantly decreased (NRS: T0 6.13 ± 0.96; T1 2.75 ± 1.69; p < 0.001), functionality improved (QuickDASH: T0 69.88 ± 10.75; T1 41.20 ± 3.78; p < 0.001), and shear wave velocity increased (SWS (m/s): T0 1.69 ± 0.35; T1 2.56 ± 0.36; p < 0.001). Conclusions: At the 2-week follow-up, pain relief was maintained, and shear wave velocity showed no further significant change. Shear wave velocity assessments might be considered a useful diagnostic tool. However, further research is needed to support the role of HPLT and shear wave velocity in the rehabilitation management of LE.

Ultrasonic shear wave elastography predicts the quality of the residual tendon before the rotator cuff repair.

BACKGROUND AND PURPOSE: Effective evaluation of rotator cuff tear residual tendon quality is the key to surgical repair. However, until now, the evaluation of rotator cuff tissue by ultrasonic shear wave elasticity (SWE) has been controversial. This prospective study analyzed the association between preoperative SWE and arthroscopic residual tendon quality scores. METHODS: The shear wave velocity (SWV) of the deltoid muscle, the supraspinatus tendon, and the supraspinatus muscle were measured in full-thickness rotator cuff tear patients. Tendon quality was scored according to tear size, tendon margin, tendon thickness, and footprint coverage during arthroscopy. The arthroscopic scores were used as the gold standard, and the SWV ratio of tendon and muscle (supraspinatus tendon/deltoid and supraspinatus muscle/deltoid) were calculated and correlated with the arthroscopic scores. RESULT: Eighty-nine patients (129 shoulders) were enrolled, including 89 operation shoulders and 40 control shoulders. In the group of operation shoulders, both the SWV ratios of tendon (SWV-RT) and the SWV ratio of muscle (SWV-RM) were negatively correlated with arthroscopic scores (The correlation coefficient (R) ranged from -0.722 to -0.884 and -0.569 to -0.689). The SWV-RT and SWV-RM of the operation shoulders were significantly lower than that of the control shoulders (p < 0.05). CONCLUSION: SWE could be used to predict the quality of the residual tendon before the rotator cuff repair. SWV of the supraspinatus tendon and muscle was a useful parameter to predict the quality of the residual tendon. CRITICAL RELEVANCE STATEMENT: Measuring the shear wave velocity of the supraspinatus tendon and muscle with SWE is useful for predicting the quality of the residual tendon which is one of the key factors for a successful rotator cuff repair. KEY POINTS: • Evaluating the quality of the residual tendon is important before surgery. • Elasticity measurements were negatively correlated with the arthroscopic score. • SWE is useful for predicting the quality of the residual tendon.

Acute Effects of Local High-Frequency Percussive Massage on Deep Fascial and Muscular Stiffness and Joint Range of Motion in Young Adult Men.

BACKGROUND: Local high-frequency percussive (HFP) massage has recently found widespread application in physical therapy. Although HFP massage reportedly improves range of motion (ROM), the mechanism underlying its action has not yet been proven. This study aimed to clarify whether a 5-minute percussive massage regimen affects muscular or connective tissues, such as the deep fascia and deep intermuscular fascia and the change in joint ROM. METHOD: The study sample was calculated using G*Power analysis program, and this study enrolled 15 healthy men who underwent 5-minute HFP massage to the medial gastrocnemius muscle. Shear-wave elastography was used to measure tissue stiffness in the deep fascia, muscle, and deep intermuscular fascia through shear-wave velocity as well as the ROM of the volunteers' ankle joint dorsiflexion before and after the HFP massage. A value of P < .05 was used to declare statistical significance, and post hoc was used to calculate the effect size using G*Power. RESULTS: Shear-wave velocity revealed a significant change in the deep fascia (P = .003; shear-wave velocity: -0.7 m/s) and significant increase in ROM of ankle dorsiflexion (P = .002; increase in ROM: 3.0°) after 5 minutes of HFP massage. However, the muscle and deep intermuscular fascia did not exhibit any significant changes. CONCLUSIONS: HFP massage for 5 minutes modified the stiffness of the deep fascia and concurrently improved the ankle joint-dorsiflexion ROM. This method can be used as an intervention to decrease stiffness of the deep fascia and increase the ROM efficiently.

Datasets of various geotechnical surveys in several arrays in the Taipei Basin.

The standard penetration test (SPT), seismic cone penetration test (SCPT), and various in-situ seismic tests are commonly utilized for geotechnical site investigations. The investigated data via these tests are widely adopted to capture site characteristics for geotechnical engineering design. However, site characterizations vary in the above in-situ tests, which leads to uncertainties in the corresponding engineering analysis and design. To address these variabilities, this paper meticulously carried out the above-mentioned geotechnical in-situ tests with rigorous supervision at 13 selected sites in the Taipei Basin, yielding several valuable datasets. The datasets consist of digital investigation data including SPT-N, soil classification, CPT-qc and -fs, and the shear wave velocities (Vs) obtained from different measurements. We believe that these datasets will be beneficial for conducting various calibration studies for different geotechnical investigation methods and the corresponding geotechnical parameters.

Our experience with liver and spleen elastography in the prediction of oesophageal varices.

Background: Variceal bleeding is an important cause of mortality in patients with chronic liver disease (CLD). The gold standard for detection and grading of oesophageal varices (EV) is upper gastrointestinal endoscopy. However, it is expensive, time-consuming and invasive. Objectives: This study aimed to find any association between splenic shear wave velocity (SWV) measured by acoustic radiation force imaging (ARFI) and the presence of EV. Method: The quasi-experimental study included 50 patients with CLD and 50 subjects without CLD as the control group. Both underwent upper abdominal ultrasonography followed by elastographic assessment on a Siemens Acuson S2000TM ultrasound system. A comparison of the findings was made between the control and patient groups. Results: Both groups had similar hepatic size while patients with CLD had larger splenic size and area (p < 0.05). The CLD patients had higher mean hepatic and splenic SWV compared with the control group (p < 0.05). The mean splenic size and splenic SWV were higher in patients with varices than in those without varices (p < 0.05). Conclusion: Chronic liver disease causes significant increase in liver and splenic stiffness with splenic SWV values being higher for patients with varices emphasising the role of elastography as a non-invasive predictor for the presence of EVs. Splenic SWV had the highest sensitivity and specificity, which was augmented by a combination of hepatic and splenic SWV. Thus, splenic SWV alone or in combination with hepatic SWV is a useful technique for prediction of the presence of EVs. Contribution: This study aims to find an alternative non-invasive and cost-effective technique for screening of EV.

Comparing the performance of machine learning methods in estimating the shear wave transit time in one of the reservoirs in southwest of Iran.

Shear wave transit time is a crucial parameter in petroleum engineering and geomechanical modeling with significant implications for reservoir performance and rock behavior prediction. Without accurate shear wave velocity information, geomechanical models are unable to fully characterize reservoir rock behavior, impacting operations such as hydraulic fracturing, production planning, and well stimulation. While traditional direct measurement methods are accurate but resource-intensive, indirect methods utilizing seismic and petrophysical data, as well as artificial intelligence algorithms, offer viable alternatives for shear wave velocity estimation. Machine learning algorithms have been proposed to predict shear wave velocity. However, until now, a comprehensive comparison has not been made on the common methods of machine learning that had an acceptable performance in previous researches. This research focuses on the prediction of shear wave transit time using prevalent machine learning techniques, along with a comparative analysis of these methods. To predict this parameter, various input features have been employed: compressional wave transit time, density, porosity, depth, Caliper log, and Gamma-ray log. Among the employed methods, the random forest approach demonstrated the most favorable performance, yielding R-squared and RMSE values of 0.9495 and 9.4567, respectively. Furthermore, the artificial neural network, LSBoost, Bayesian, multivariate regression, and support vector machine techniques achieved R-squared values of 0.878, 0.8583, 0.8471, 0.847 and 0.7975, RMSE values of 22.4068, 27.8158, 28.0138, 28.0240 and 37.5822, respectively. Estimation analysis confirmed the statistical reliability of the Random Forest model. The formulated strategies offer a promising framework applicable to shear wave velocity estimation in carbonate reservoirs.

Normal value of virtual touch imaging quantification elastography in measurements of pancreas.

OBJECTIVE: To evaluate pancreatic tissue stiffness and provide a normal reference shear wave velocity (SWV) value of pancreas from healthy adults by Virtual Touch Imaging Quantification (VTIQ) measurements. METHODS: Healthy adult volunteers without known history of hepatobiliary or pancreatic diseases were included. VTIQ elastography (Siemens ACUSON Sequoia, 5C-1 transducer) was used. SWV values were measured at the cephalic, corpus and tail of pancreas and replicated different operators' obtained data. Subgroups were classified according to the volunteers' gender, age, body mass index (BMI), depth of measurements and the echogenicity of the pancreas. RESULTS: From February 2023 to July 2023, 33 healthy adult volunteers were included. The success rate of VTIQ measurements in cephalic, corpus and tail regions was 90.90 % (30/33), 96.97 % (32/33) and 90.90 % (30/33) respectively. The color elastograms of healthy adult pancreas showed uniform blue or simultaneously blue and green. The average SWV values were 0.97±0.26 m/s for cephalic, 0.91±0.24 m/s for corpus and 0.97±0.25 m/s for pancreatic tail respectively (P = 0.198). The mean SWV values of pancreas did not show significant difference with age, gender or depth (P > 0.05). BMI was an influence factor in the measurements of SWV values of cephalic and tail of pancreas (P < 0.05). Pancreas with hyperechoic parenchyma showed higher mean SWV values (P < 0.05). The intra-observer (ICC = 0.938 [95% CI: 0.869-0.971]) and the inter-observer (ICC = 0.887 [95% CI: 0.760-0.947]) agreements of VTIQ measurements were excellent. CONCLUSIONS: The mean SWV value of the pancreas in healthy adults was 0.96±0.20 m/s (range: 0.52-1.74 m/s). VTIQ technique can be used in pancreatic stiffness measurements with good reliability.

Evaluating Skin Involvement in Systemic Sclerosis Using High-Frequency Ultrasound and Virtual Touch Tissue Imaging.

OBJECTIVE: This study aimed to explore the diagnostic significance of high-frequency ultrasound combined with visual touch tissue imaging quantification (VTIQ) in the diagnosis and management of systemic sclerosis (SSc). METHODS: Patients diagnosed with SSc and normal volunteers were recruited and divided into an experimental group and a control group, with 30 cases in each group, respectively. The skin thickness at six sites was assessed using high-frequency ultrasound, and the shear wave velocity (SWV) was determined using the VTIQ method. The differences in skin thickness and SWV between the experimental group and the control group were compared and a receiver operating characteristic (ROC) curve was plotted. The value of high-frequency ultrasound, VTIQ, and high-frequency ultrasound combined with VTIQ for evaluating skin involvement in SSc was determined. RESULTS: The difference in SWV sum at six sites and the thickness sum was statistically significant (all p = 0.000 < 0.05) from that of the control group, and there was a strong association between the SWV sum, thickness sum, and Rodnan skin score at the six sites in the experimental group (p = 0.000, r = 0.726; p = 0.000, r = 0.679). Based on the ROC curve, the area under the curve (AUC) for high-frequency ultrasound examination was 0.789. The AUC for VTIQ examination was 0.893, while the AUC for high-frequency ultrasound combined with VTIQ examination was 0.923. The combined examination method showed the highest AUC, indicating the best diagnostic performance. CONCLUSION: The integration of high-frequency ultrasound and VTIQ provides a quantitative approach for assessing the extent of skin involvement in SSc patients, offering valuable insights for clinical diagnosis and treatment purposes.

Ultrasound-based quantitative tools in predicting renal involvement in asymptomatic primary hyperparathyroidism.

PURPOSE: Asymptomatic primary hyperparathyroidism (aPHPT) has been recognized as a condition that can lead to renal complications. Timely identification of prognostic indicators for renal impairment holds the potential to facilitate proactive monitoring and treatment strategies in these patients. This study aims to investigate the utility of acoustic radiation force impulse (ARFI) imaging and renal resistive index (RRI), in identifying renal parenchymal and vascular changes in patients with aPHPT. METHODS: Forty-two patients with aPHPT and 42 controls matched for age, sex, and body mass index were included in the study. The presence of renovascular changes was evaluated by RRI measurement with Doppler ultrasonography, and the presence of renal parenchymal involvement was evaluated by ARFI quantification, given as shear wave velocity (SWV). RESULTS: In aPHPT patients, both the mean RRI and mean SWV values exhibited substantial elevation compared to the control group (P < 0.001 for both). Significant associations were observed between SWV values and serum calcium, parathyroid hormone (PTH), and adenoma size within the patient group (P < 0.001, P < 0.001, P = 0.016, respectively). Similarly, the mean RRI demonstrated positive correlations with serum calcium and PTH levels in the patient group (P< 0.001, P = 0.011, respectively). Multivariate linear regression analysis underscored the connection between mean RRI and mean SWV values with serum calcium levels within the patient group. In addition, serum PTH levels affected mean SWV positively and significantly. CONCLUSION: The use of ARFI imaging and RRI measurements appears to hold potential in identifying renal involvement in patients with aPHPT.