Elastography Research Articles

Association between blood chromium and hepatic steatosis assessed by liver ultrasound transient elastography: National Health and Nutrition Examination Survey 2017-2020.

Hepatic steatosis is a significant pathological feature of fatty liver disease (FLD) which is widely spread with no effective treatment available. Previous studies suggest that chromium (Cr) intake reduces lipid deposition in the liver in animals. However, the connection between blood Cr and hepatic steatosis among humans remains inconclusive. Using the data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020, we performed a cross-sectional analysis, including 4,926 participants. The controlled attenuation parameter (CAP) measured by the vibration controlled transient elastography (VCTE) was used to evaluate the degree of liver steatosis. Weighted univariate regression, multivariate linear regression, smooth fitting curves and subgroup analysis were used. In addition, we carried out trend tests, multiple interpolations, and interaction analyses to conduct sensitivity analyses. After adjusting with various covariables, multivariate linear regression analysis demonstrated a significant negative correlation between blood Cr and CAP [β (95% CI) = -5.62 (-11.02, -0.21)]. The negative correlation between blood Cr and CAP was more significant in the males, 50-59 years, overweight, hypercholesterolemia, HDL-C ≥ 65 mg/dL, HbA1c (5.70-6.10 %), HOMA-IR (0.12-2.76), total bilirubin (0.30-0.40 mg/dL), ever alcohol consumption subjects. Of note, the relationships between blood Cr and CAP followed a U-shaped curve in the smokers and non-smokers, with blood Cr thresholds of 0.48, 0.69 μg/L, respectively. There is an independently negative correlation between blood Cr and hepatic steatosis in American. Our study provides clinical researchers with a new insight into the prospective prevention of hepatic steatosis.

Endoscopic Ultrasound-based Shear Wave Elastography for Detection of Advanced Liver Disease.

Endoscopic ultrasound shear wave elastography (EUS-SWE) is a novel modality for liver stiffness measurement. The aims of this study are to evaluate the performance and reliability of EUS-SWE for detecting advanced liver disease in a prospective cohort. EUS-SWE measurements were prospectively obtained from patients undergoing EUS between August 2020 and March 2023. Liver stiffness measurements were compared between patients with and without advanced liver disease (ALD), defined as stage ≥3, to determine diagnostic accuracy for advanced fibrosis and portal hypertension. Logistic regression was performed to identify variables that impact the reliability of EUS-SWE readings. Select patients underwent paired magnetic resonance elastography (MRE) for liver fibrosis correlation. Patients with ALD demonstrated higher liver stiffness compared to healthy controls (left lobe: 17.6 vs. 12.7 kPa, P<0.001; median right lobe: 24.8 vs. 11.0 kPa, P<0.001). The area under the receiver operator characteristic (AUROC) for the detection of ALD was 0.73 and 0.80 for left and right lobe measurements, respectively. General anesthesia was associated with reliable EUS-SWE liver readings (odds ratio: 2.73, 95% CI: 1.07-7.39, P=0.040). Left lobe measurements correlated significantly with MRE with an increase of 0.11 kPa (95% CI: 0.05-0.17 kPA) for every 1 kPa increase on EUS-SWE. D. SWE is a promising technology that can readily be incorporated into standard EUS examinations for the assessment of ALD.

Teacher-student guided knowledge distillation for unsupervised convolutional neural network-based speckle tracking in ultrasound strain elastography.

Accurate and efficient motion estimation is a crucial component of real-time ultrasound elastography (USE). However, obtaining radiofrequency ultrasound (RF) data in clinical practice can be challenging. In contrast, although B-mode (BM) data is readily available, elastographic data derived from BM data results in sub-optimal elastographic images. Furthermore, existing conventional ultrasound devices (e.g., portable devices) cannot provide elastography modes, which has become a significant obstacle to the widespread use of traditional ultrasound devices. To address the challenges above, we developed a teacher-student guided knowledge distillation for an unsupervised convolutional neural network (TSGUPWC-Net) to improve the accuracy of BM motion estimation by employing a well-established convolutional neural network (CNN) named modified pyramid warping and cost volume network (MPWC-Net). A pre-trained teacher model based on RF is utilized to guide the training of a student model using BM data. Innovations outlined below include employing spatial attention transfer at intermediate layers to enhance the guidance effect of the model. The loss function consists of smoothness of the displacement field, knowledge distillation loss, and intermediate layer loss. We evaluated our method on simulated data, phantoms, and in vivo ultrasound data. The results indicate that our method has higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values in axial strain estimation than the model trained on BM. The model is unsupervised and requires no ground truth labels during training, making it highly promising for motion estimation applications.

Association of the rate of torque development and joint angle with passive muscle stiffness.

The purpose of this study was to statistically compare the rate of torque development normalized by maximal strength (relative RTD) across ankle angles. Additionally, this study was aimed at exploring the correlation coefficients between relative RTD and passive stiffness of the medial gastrocnemius (MG) at different ankle angles. Twenty-two healthy men and women (age: 31 ± 4 years) performed randomly-ordered explosive isometric plantar flexions at plantarflexed (15°), neutral (0°), and dorsiflexed (- 15°) angles; relative RTD comprised the slope of the time-torque curve normalized to maximal torque. The shear wave velocity (SWV; index of stiffness) of the MG at rest was measured at each angle using ultrasound shear wave elastography. The relative RTD was greater at 15° than - 15° for 0-50, 0-100, and 0-150 ms time-windows and at 15° than 0° for the 0-150 ms time-window (P < 0.05), although peak torque was lower at 15° than 0° and - 15° (P < 0.05). The relative RTD for the 0-50 ms time-window correlated with SWV at - 15° (rs = 0.475, P < 0.05), but not at 15º and 0º. Furthermore, the correlation coefficient of RTD for the 0-100 ms time-window with SWV was significantly greater at - 15° (rs = 0.420) than 0 ° (rs = - 0.109). A greater relative RTD occurs at plantarflexed angles (i.e., the ascending limb of the force-length curve) in the triceps surae, and relative RTD is strongly related to passive MG stiffness at dorsiflexed angles (i.e., longer muscle lengths).

Effect of proteinuria at relapse on shear wave velocity assessed using ultrasound elastography in children with idiopathic nephrotic syndrome.

Shear wave velocity (SWV) is an ultrasound elastography technique that provides much information for kidney disease assessment. However, the factors that alter SWV are not fully understood; it is unclear whether the variation in SWV seen in proteinuria associated with disease progression is due to tissue or proteinuria. This study investigated the effect of proteinuria on SWV. This prospective observational study compared SWV at remission with SWV at relapse in children treated for idiopathic nephrotic syndrome (INS) between April 2020 and December 2023. All relapses without oral steroids during the observation period were measured. SWV at remission was defined as the date closest to relapse during which repeated measurements were taken approximately every 3months after steroid discontinuation. Eight patients were treated for INS with a median observation period of 21.9months (11.8-27.1). Of the 15 relapses, five that met the definition were considered for the study. The median interval between the measurement at relapse and remission was 40days (11-55). SWV was significantly lower at relapse than remission (2.40 ± 0.20m/s vs. 2.14 ± 0.15m/s, P < 0.01). SWV decreased in the presence of severe proteinuria at relapse compared to the remission measurements. Although more cases need to be studied, the decrease in SWV may reflect the mechanism by which protein leaks into the urine, not just a direct change caused by the presence of proteinuria.

Merging single-track location Elastographic imaging with the frequency shift method improves shear wave attenuation measurements

The frequency shift (FS) method is emerging as the standard approach for estimating shear wave attenuation coefficient (SWA). However, measurement noise can negatively impact the FS method’s accuracy, especially when employed in vivo. We hypothesized that combining plane wave single-track location shear wave elastography imaging with the FS method would reduce this problem. To test our hypothesis, we performed studies on calibrated phantoms and two groups of in vivo murine liver: control and obese mice. We evaluated the performance of various SWA methods, including the plane wave single-track location frequency shift (pSTL-FS) method that we recently developed, the original FS method, and the attenuation-measuring-shear-wave ultrasound elastography (AMUSE) method. We also assessed the effectiveness of assuming a Gaussian distribution versus a Gamma distribution for the shear wave spectrum when estimating SWA coefficients with the pSTL-FS and FS methods. The actual SWA coefficients of the phantoms were determined by performing independent mechanical testing on representative samples. The accuracy incurred when estimating SWA ranged from 84.69% to 97.55% for pSTL-FS (Gamma), 51.37%–72.18% for pSTL-FS (Gaussian), 40.33%–57.00% for FS (Gamma), 39.33%–55.37% for FS (Gaussian), and 59.25%–99.22% for AMUSE. The results of studies performed on murine livers (n = 10) revealed that assuming a Gaussian distribution during pSTL-FS imaging resulted in lower attenuation values than when a Gamma distribution was assumed. We also observed that pSTL-FS (Gamma) resulted in the highest significant difference between control and obese mice than all other approaches (p-value &amp;lt;0.0001). We also observed that the standard FS method with either Gamma or Gaussians produced lower attenuation estimates than pSTL-FS, AMUSE and mechanical testing. The mean attenuation coefficients of the murine livers measured with the pSTL-FS (Gamma and Gaussian functions) methods were consistently higher than those computed with the standard FS methods but lower than those computed with the AMUSE method. Our results demonstrated that combining the pSTL method with FS method provided more robust estimates of the SWA coefficient. For the murine livers, a Gamma distribution is more representative of the shear wave frequency spectrum than a Gaussian distribution.

Shear wave ultrasound elastography for estimating cartilage stiffness: implications for early detection of osteoarthritis

Current osteoarthritis (OA) diagnosis relies on radiographic abnormalities found in later stages of the disease, posing a challenge to the treatment efficacy. Therefore, earlier detection of OA is essential for improving therapeutic outcomes. The aim of this study was to investigate the feasibility of shear wave ultrasound elastography (SWUE) to detect changes in cartilage mechanical properties under OA conditions ex-vivo. Bovine osteochondral units were harvested from femoral condyles and subjected to either trypsin degradation, cartilage surface roughness defect using varying degrees of sandpaper, or subchondral bone degeneration using formic acid (FA) injection. Shear waves were generated using a mechanical shaker, while a high-frequency ultrasound system operating at 18 MHz was employed to detect wave propagation along the samples. The elasticity of cartilage was estimated by the shear wave speed (SWS) through the auto-correlation method. Our results show that the estimated SWS of cartilage after 24, 48, and 72 hours of trypsin incubation significantly decreased by 37%, 43%, and 59%, respectively, compared to the control group. Surface roughness treatment using 150-grit sandpaper significantly decreased the SWS by 35% compared to the control. Samples treated with 7% FA showed a significant increase in SWS by 62%, 89%, and 53% compared to control, 1% FA, and 3% FA, respectively. Our findings demonstrate the feasibility of SWUE to differentiate the elastic properties of cartilage under different OA conditions. This study presents the potential of a noninvasive, nonionizing tool for early detection of OA, representing a significant step toward its clinical implementation.Graphical

Non-invasive in vivo study of morphology and mechanical properties of the median nerve.

The current literature studied the median nerve (MN) at specific locations during joint motions. As only a few particular parts of the nerve are depicted, the relevant information available is limited. This experiment investigated the morphological and biomechanical properties of the MN. The effects of the shoulder and wrist motions on MN were explored as well. Eight young healthy female individuals were tested with two-dimensional ultrasound and shear wave elastography (SWE). The morphological and biomechanical properties were examined in limb position 1, with the wrist at the neutral position, the elbow extended at 180°, and the shoulder abducted at 60°. In addition, the experiment assessed the differences among the wrist, forearm, elbow, and upper arm with Friedman's test and Bonferroni post hoc analysis. Two groups of limb positions were designed to explore the effects of shoulder movements (shoulder abducted at 90° and 120°) and wrist movements (wrist extended at 45° and flexed at 45°) on the thickness and Young's modulus. Differences among the distributions of five limb positions were tested as well. The ICC3, 1 values for thickness and Young's modulus were 0.976 and 0.996, respectively. There were differences among the MN thicknesses of four arm locations in limb position 1, while Young's modulus was higher at the elbow and wrist than at the forearm and upper arm. Compared to limb position 1, only limb position 4 had an effect on MN thickness at the wrist. Both shoulder and wrist motions affected MN Young's modulus, and the stiffness variations at typical locations all showed a downward trend proximally in all. The distributions of MN thickness and Young's modulus showed fold line patterns but differed at the wrist and the pronator teres. The MN in the wrist is more susceptible to limb positions, and Young's modulus is sensitive to nerve changes and is more promising for the early diagnosis of neuropathy.

Ultrasonic surface acoustic wave elastography: A review of basic theories, technical developments, and medical applications.

Physiological and pathological changes in tissues often cause changes in tissue mechanical properties, making tissue elastography an effective modality in medical imaging. Among the existing elastography methods, ultrasound elastography is of great interest due to the inherent advantages of ultrasound imaging technology, such as low cost, portability, safety, and wide availability. However, most current ultrasound elastography methods are based on the bulk shear wave; they can image deep tissues but cannot image superficial tissues. To address this challenge, ultrasonic elastography methods based on surface acoustic waves have been proposed. In this paper, we present a comprehensive review of ultrasound-based surface acoustic wave elastography techniques, including their theoretical foundations, technical implementations, and existing medical applications. The goal is to provide a concise summary of the state-of-the-art of this field, hoping to offer a reliable reference for the further development of these techniques and foster the expansion of their medical applications.

Preoperative ultrasound radiomics for predicting clinically relevant postoperative pancreatic fistula after pancreatectomy.

To evaluate the efficacy of the radiomics model based on preoperative B-mode ultrasound (BMUS) and shear wave elastography (SWE) for predicting the occurrence of clinically relevant-postoperative pancreatic fistula (CR-POPF). Patients who were scheduled to undergo pancreatectomy were prospectively enrolled and received ultrasound assessment within one week before surgery. The risk factors of POPF (grades B and grades C) were analyzed. Preoperative BMUS images, SWE values of pancreatic lesions and surrounding parenchyma were used to build preoperative prediction radiomics models. Radiomic signatures were extracted and constructed using a minimal Redundancy Maximal Relevance (mRMR) algorithm and an L1 penalized logistic regression. A combined model was built using multivariate regression which incorporated radiomics signatures and clinical data. From January 2020 to November 2021, a total of 147 patients (85 distal pancreatectomies and 62 pancreaticoduodenectomies) were enrolled. During the three-week follow-up after pancreatectomy, the incidence rates of grade B/C POPF were 28.6% (42/147). Radiomic signatures constructed from BMUS of pancreas parenchymal regions (panRS) achieved an area under the receiver operating characteristic curve (AUC) of 0.75, accuracy of 68.7%, sensitivity of 85.7 %, and specificity of 61.9 % in preoperative noninvasive prediction of CR-POPF. The AUC of the radiomics model increased to 0.81 when panRS was used for the prediction of CR-POPF after pancreaticoduodenectomy. Radiomics model based on ultrasound images was potentially useful for predicting CR-POPF. Patients with high-risk factors should be closely monitored when postoperation.

Effects of foam rolling on hamstrings stiffness in damaged and non-damaged muscle states.

Introduction: The aim of this study was to examine the effects of foam rolling (FR) on hamstring muscles stiffness in both non-damaged and exercise-induced muscle damage (EIMD) states, using shear wave ultrasound elastography to measure changes in shear modulus. Methods: Fourteen healthy adults (25.5 ± 4.7 years) participated in a within-participant repeated measures design, with a 2-minute FR intervention applied on one leg and contralateral leg serving as a control. The damaging protocol encompassed maximal eccentric knee extensions performed on an isokinetic dynamometer and the Nordic hamstring exercise, consisting of 3 sets of 10 and 6 repetitions, respectively. Measurement were taken at baseline and then 1h, 24h and 48h after the damaging protocol. Results: The results indicated no significant time × leg interaction for shear modulus in biceps femoris, semimembranosus, and semitendinosus muscles in both non-damaged and damaged states. Notably, there was a significant increase in biceps femoris (p = 0.001; η2 = 0.36) and semitendinosus (p < 0.001; η2 = 0.44) shear modulus after EIMD, but no significant differences were found between the FR and control leg, which was also the case for muscle soreness, range of motion, and passive resistive torque (p = 0.239-0.999 for interactions). Discussion: The absence of significant changes post-FR intervention suggests a limited role of short-duration FR in altering muscle stiffness during recovery from EIMD. These findings contribute to the understanding of FR's role in muscle recovery. Although this was not directly investigated, our results suggest a predominance of central mechanisms rather than direct mechanical modifications in muscle properties. This research highlights the necessity for additional investigations to explore how FR interventions influence muscles in different states and to elucidate the mechanisms underlying these influences.

Stabilizing Tumor-Resident Mast Cells Restores T-Cell Infiltration and Sensitizes Sarcomas to PD-L1 Inhibition.

To explore the cellular cross-talk of tumor-resident mast cells (MC) in controlling the activity of cancer-associated fibroblasts (CAF) to overcome tumor microenvironment (TME) abnormalities, enhancing the efficacy of immune-checkpoint inhibitors in sarcoma. We used a coculture system followed by further validation in mouse models of fibrosarcoma and osteosarcoma with or without administration of the MC stabilizer and antihistamine ketotifen. To evaluate the contribution of ketotifen in sensitizing tumors to therapy, we performed combination studies with doxorubicin chemotherapy and anti-PD-L1 (B7-H1, clone 10F.9G2) treatment. We investigated the ability of ketotifen to modulate the TME in human sarcomas in the context of a repurposed phase II clinical trial. Inhibition of MC activation with ketotifen successfully suppressed CAF proliferation and stiffness of the extracellular matrix accompanied by an increase in vessel perfusion in fibrosarcoma and osteosarcoma as indicated by ultrasound shear wave elastography imaging. The improved tissue oxygenation increased the efficacy of chemoimmunotherapy, supported by enhanced T-cell infiltration and acquisition of tumor antigen-specific memory. Importantly, the effect of ketotifen in reducing tumor stiffness was further validated in sarcoma patients, highlighting its translational potential. Our study suggests the targeting of MCs with clinically administered drugs, such as antihistamines, as a promising approach to overcome resistance to immunotherapy in sarcomas.

Application of ultrasonography in diagnosis and treatment of children with congenital muscular torticollis.

Congenital muscular torticollis (CMT) is a more common childcare disease, which belongs to muscle-skeletal system diseases, and is more common in newborns. The disease is mainly due to congenital contracture due to chest locks, which leads to asymmetric head and neck. For such diseases, clear diagnosis and treatment in the early days is an important way to improve the prognosis of children. Compared with X-ray film, CT, and MRI, ultrasound examination has the advantages of low examination cost, short time, and no exposure to radiation during the examination. Moreover, ultrasound examination can provide an objective basis for the clinical diagnosis and prognosis evaluation of CMT children. This article reviews the latest research progress of conventional ultrasound, color Doppler ultrasound, and ultrasound elastography in the clinical diagnosis of CMT children and assisting in the formulation of treatment plans.

(1072) - Correlation of Liver Fibrosis on Ultrasound Elastography and Liver Biopsy After Fontan Operation: Is Non-Invasive Always Better?

(1072) - Correlation of Liver Fibrosis on Ultrasound Elastography and Liver Biopsy After Fontan Operation: Is Non-Invasive Always Better?

Changes in liver health biomarkers following consumption of energy restricted diets containing almonds compared with carbohydrate-rich snack foods for 9 months

Energy restricted diets improve liver function(1) and habitual nut consumption has been associated with a lower prevalence of fatty liver(2). This study examined the effect of incorporating almonds in an energy restricted diet on liver health biomarkers. One Hundred and forty adults (42M:98F, 47.5 ± 10.8 years, BMI 30.7 ± 2.3 kg/m2) enrolled in a 9-month (9M) dietary intervention comprising 3 months (3M) weight loss (30% energy restriction) followed by 6 months (6M) of weight maintenance. Participants were randomly assigned to consume almonds (n = 68, AED) or isocaloric carbohydrate-rich snacks (n = 72, CRD) which provided 15% of total daily energy. At baseline (BL), 3M and 9M, fatty liver index (FLI) scores (0-100)(3) were calculated using body mass index (BMI), waist circumference (WC), fasting serum gamma-glutamyl transferase (GGT) and triglyceride (TAG) levels, and other liver health biomarkers were assessed by ultrasound (volume, visual appearance and elastography (a marker of stiffness due to fibrosis)). Intention to treat analyses were conducted using mixed effects modelling (fixed effects group and time, with participants as the random effect). Significant reductions from BL occurred over time (all p&lt;0.001 for 3M and 9M) with no difference between groups (AED vs CRD, P&gt;0.05) in BMI (3M: −2.44 ± 0.20 vs −2.32 ± 0.20, 9M: −2.83 ± 0.19 vs −2.81 ± 0.19 kg/m2), WC (3M: −8.04 ± 0.79 vs −7.00 ± 0.81, 9M: −8.72 ± 0.83 vs −9.14 ± 0.81 cm), TAG (3M: −0.24± 0.08 vs −0.22 ± 0.09, 9M: −0.37 ± 0.09 vs −0.21 ± 0.09 mmol/L), FLI score (3M: −23.8 ± 2.0 vs −17.6 ± 2.1, 9M: −23.8 ± 2.0 vs −17.6 ± 2.1), and liver volume (3M: −134.56 ± 38.30 vs −100.96 ± 37.25, 9M: −113.68 ± 37.42 vs −110.64 ± 35.47cm3). Significantly greater reductions occurred for AED compared to CRD at 3M and 9M in GGT (p = 0.003) (3M: −9.68 ± 1.93 vs −0.01 ± 2.00, 9M: −7.75 ± 2.06 vs −2.78 ± 2.15 IU/L) and liver visual assessment scores (p = 0.03) (3M: −0.58 ± 0.24 vs −0.45 ± 0.23, 9M: −1.33 ± 0.23 vs −0.50 ± 0.22). There were no significant changes in liver elastography over time or between groups. Energy restriction improved body composition and reduced the extent of fatty liver and liver size but did not change liver stiffness. The inclusion of almonds in an energy restricted diet demonstrated additional benefits to some liver health biomarkers providing support for almonds being incorporated into lifestyle interventions to improve liver function.

Influence of toe flexor muscle fatigue on stiffness of the intrinsic foot muscles

BACKGROUND: Assessing intrinsic foot muscles (IFM) is important for understanding their role in loading movements. Additionally, knowledge of the impact of IFM following toe flexor muscle fatigue may aid the teaching of IFM exercises. OBJECTIVE: To examine the influence of toe flexor muscle fatigue on IFM stiffness using ultrasound shear-wave elastography. METHODS: This study included 19 college students. IFM stiffness at 10%, 50%, and 90% body weight was measured using ultrasound-based shear-wave elastography. IFM including the abductor hallucis (AbH), flexor hallucis brevis (FHB), flexor digitorum brevis (FDB), and quadratus plantae (QP) were assessed. The fatigue induction protocol comprised a series of toe flexions at a controlled pace of 40 beats per minute and an amplitude of 75% of the maximum toe flexor strength for a duration of 5 minutes. RESULTS: Muscle stiffness significantly increased with increasing load. Toe flexor muscle fatigue significantly increased the stiffness of the FDB. CONCLUSIONS: IFM stiffness significantly increased with increasing load, and the stiffness of FDB significantly increased in the toe flexor muscle fatigue condition at DLS and SLS loads. The findings of this study will contribute to the study and clinical setting of IFM exercises.

In vivo bistatic dual-aperture ultrasound imaging and elastography of the abdominal aorta.

Introduction: In this paper we introduce in vivo multi-aperture ultrasound imaging and elastography of the abdominal aorta. Monitoring of the geometry and growth of abdominal aortic aneurysms (AAA) is paramount for risk stratification and intervention planning. However, such an assessment is limited by the lateral lumen-wall contrast and resolution of conventional ultrasound. Here, an in vivo dual-aperture bistatic imaging approach is shown to improve abdominal ultrasound and strain imaging quality significantly. By scanning the aorta from different directions, a larger part of the vessel circumference can be visualized. Methods: In this first-in-man volunteer study, the performance of multi-aperture ultrasound imaging and elastography of the abdominal aortic wall was assessed in 20 healthy volunteers. Dual-probe acquisition was performed in which two curved array transducers were aligned in the same imaging plane. The transducers alternately transmit and both probes receive simultaneously on each transmit event, which allows for the reconstruction of four ultrasound signals. Automatic probe localization was achieved by optimizing the coherence of the trans-probe data, using a gradient descent algorithm. Speckle-tracking was performed on the four individual bistatic signals, after which the respective axial displacements were compounded and strains were calculated. Results: Using bistatic multi-aperture ultrasound imaging, the image quality of the ultrasound images, i.e., the angular coverage of the wall, was improved which enables accurate estimation of local motion dynamics and strain in the abdominal aortic wall. The motion tracking error was reduced from 1.3 mm ± 0.63 mm to 0.16 mm ± 0.076 mm, which increased the circumferential elastographic signal-to-noise ratio (SNRe) by 12.3 dB ± 8.3 dB on average, revealing more accurate and homogeneous strain estimates compared to single-perspective ultrasound. Conclusion: Multi-aperture ultrasound imaging and elastography is feasible in vivo and can provide the clinician with vital information about the anatomical and mechanical state of AAAs in the future.

Relationship between the Duration of Suffering from Diabetes and HbA1c Levels with the Degree of Liver Stiffness in Type 2 Diabetes Mellitus Patients

BACKGROUND : Type 2 diabetes mellitus (DM) is one of the major problems faced by the health system. Diabetes is a multifactorial, chronic and progressive metabolic disorder characterized by chronic hyperglycemia. Persistent hyperglycemia is associated with long-term damage to the liver. Ultrasound elastography is one of imaging modality that can assess liver stiffness, thus can assist clinicians in determining therapy, evaluating, and predicting disease progression. AIMS : Aim of this study was to determine the relationship between liver stiffness degree by using ultrasound elastography with the duration of T2DM and HbA1c levels. METHOD : This study was an observational analytic research with a cross-sectional approach which carried out from May to September 2022 at the radiology department of Dr. Kariadi Hospital Semarang. Fifty subjects were included in this study and Rank-Spearman correlation test was used to analyze the relationship between liver stiffness degree with T2DM duration and HbA1c levels. RESULT : Using ultrasonography elastography, the liver stiffness average was 7.92 + 6.72 kPa. The average of HbA1c levels was 8.55 + 2.63%. T2DM duration average was 9.10 + 6.50 years. The rank-spearman test showed a significant correlation between HbA1c levels and the degree of liver stiffness (p = 0.000) with a correlation coefficient (r) of 0.68. There was no significant correlation between the T2DM duration and the degree of liver stiffness (p = 0.052). CONCLUSION : There was a significant correlation between liver stiffness and HbA1c levels, but there is no correlation between liver stiffness and T2DM duration

VENOUS THROMBUS STIFFNESS IN COMBINATION OF PULMONARY EMBOLISM AND DEEP VEIN THROMBOSIS OF THE LOWER EXTREMITIES (CLINICAL CASE)

Many aspects of pulmonary embolism pathogenesis are still unclear: for example, what is the probability of pulmonary embolization in venous thrombosis and thrombi formation in the pulmonary artery in situ. The origin and timing of thromboemboli formation in the pulmonary artery are of great clinical importance for effective treatment and prognosis of pulmonary embolism outcome. The aim of the study was as part of clinical observation to compare the results of shear wave ultrasound elastography of a venous thrombus and the histological structure of blood clots in the lower extremity and the pulmonary artery obtained during a pathoanatomical examination. Research results. Patient Sh., 67 years old, was hospitalized with a diagnosis of pulmonary embolism. Ultrasound imaging visualized heterogeneous, predominantly hypoechoic non-occlusive thrombotic masses in the lumen of the posterior tibial vein of the left lower limb, extending into the lumen of the popliteal vein for 2 cm with an uneven "ragged" contour of the proximal part of the thrombus, without clear signs of flotation. Shear wave ultrasound elastography determined stiffness of the proximal part of the venous thrombus with an average Young's modulus of 8.5 kPa, which corresponds to the acute stage of thrombosis. Negative dynamics was observed after thrombolytic therapy. Computed tomography angiography of the cerebral vessels revealed signs of intracerebral hemorrhage. On the third day, the patient was pronounced dead. The pathological examination was supplemented with histological data from a fragment of a venous thrombus of the pulmonary artery and lower leg veins. The morphological characteristics of blood clots from the veins of the lower extremities and the pulmonary artery coincided, indicating their common origin and the time of formation (acute stage). Conclusion. A comparative analysis of ultrasound and pathoanatomical data of the clinical case give us the opportunity to recommend shear wave ultrasound elastography of venous thrombi of the lower extremities to assess the state of thromboembolism in the pulmonary artery.

Advancements in the application of uterine ultrasound elastography.

This article reviews recent advances in ultrasound elastography in diagnosing and evaluating the normal nongravid uterus and the infertile uterus in the gynecologic patient. 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. 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.