Shear Wave Elastography Method Research Articles

Comparison of US elastography and chemical shift magnetic resonance imaging in multifidus muscle fatty degeneration.

The purpose of this study was to investigate the feasibility of the use of shear wave elastography (SWE) in comparison to chemical shift encoding (CSE) magnetic resonance imaging (MRI) for the evaluation of multifidus muscle fatty degeneration in patients with chronic low back pain. Multifidus muscles were evaluated with the CSE-MRI and SWE examinations in control and patient groups. With the in-phase and out-phase sequences in CSE-MRI, signal intensity index (SII), and signal intensity suppression ratio (SISR) values; with the SWE method, shear wave velocity values were determined. Differences in the mean values of these parameters per level and study group were analyzed by Student's t-test. SWE revealed significantly lower stiffness at the L2-3 level, consistent with the signal index values (SII-SISR) showing increased fatty infiltration on MRI in the patient group. No such relationship was found at the L4-5 level or in control group. SWE may be a promising method to show muscle fatty infiltration at L2-3 level in patients with chronic low back pain.

Imaging the intramuscular pressure of living muscles with shear waves

Shear wave elastography (SWE) is an innovative method that allows for the nondestructive and quantitative characterization of muscular mechanical properties. This method finds extensive utility in fields such as sports medicine, sports rehabilitation, and the diagnosis of muscle-related ailments. Existing studies have demonstrated the promise of SWE in probing intramuscular pressure (IMP), a factor intimately tied to muscular physiological functions and the onset of certain diseases. Nonetheless, there remains a lack of a SWE method grounded in an appropriate biomechanical model capable of effectively imaging IMP in vivo. Addressing this issue, we propose a shear wave imaging method relaying on a porohyperelastic model encompassing well-defined parameters for both muscular active behavior and intramuscular pressure. Drawing upon wave motion analysis, we establish a correlation between shear wave velocities and IMP in analytical form. This theoretical solution on one hand help understand the interplay between IMP and muscle active stress and the impact of muscle contraction on IMP. On the other hand, it enables us to develop an elastography method to assess IMP in vivo. We conducted a series of experiments to underscore the applicability of our theory and elastography method. Ex vivo experiments were performed on porcine muscles, while in vivo tests were carried out on human skeletal muscles. The results from the ex vivo tests validate the efficacy of our method. Meanwhile, the in vivo outcomes suggest that our approach holds potential to assess the variation of IMP with muscle fatigue and injuries, inspect intramuscular injections, and diagnose acute and chronic compartment syndrome.

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

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

SWENet: A Physics-Informed Deep Neural Network (PINN) for Shear Wave Elastography.

Shear wave elastography (SWE) enables the measurement of elastic properties of soft materials in a non-invasive manner and finds broad applications in various disciplines. The state-of-the-art SWE methods rely on the measurement of local shear wave speeds to infer material parameters and suffer from wave diffraction when applied to soft materials with strong heterogeneity. In the present study, we overcome this challenge by proposing a physics-informed neural network (PINN)-based SWE (SWENet) method. The spatial variation of elastic properties of inhomogeneous materials has been introduced in the governing equations, which are encoded in SWENet as loss functions. Snapshots of wave motions have been used to train neural networks, and during this course, the elastic properties within a region of interest illuminated by shear waves are inferred simultaneously. We performed finite element simulations, tissue-mimicking phantom experiments, and ex vivo experiments to validate the method. Our results show that the shear moduli of soft composites consisting of matrix and inclusions of several millimeters in cross-section dimensions with either regular or irregular geometries can be identified with excellent accuracy. The advantages of the SWENet over conventional SWE methods consist of using more features of the wave motions and enabling seamless integration of multi-source data in the inverse analysis. Given the advantages of SWENet, it may find broad applications where full wave fields get involved to infer heterogeneous mechanical properties, such as identifying small solid tumors with ultrasound SWE, and differentiating gray and white matters of the brain with magnetic resonance elastography.

Application of continuous shear wave elastography method with multiple frequency selection to liver viscoelasticity measurement

In this study, we present a method for evaluating liver viscoelasticity using continuous shear wave elastography with an arbitrary frequency selection. In the Voigt model, viscosity depends on the frequency of shear waves, thus allowing viscosity evaluation by combining measurements at different frequencies. The shear wave frequency must satisfy the continuous shear-wave elastography frequency conditions. Therefore, the shear-wave frequency was selected as an integer fraction of the pulse repetition frequency of the ultrasound device. Low-viscosity phantoms were used in this study. The frequency dependence of shear-wave velocity was confirmed using a viscous phantom. The shear wave velocity dispersion measured using the proposed method was 5.41–8.98 m/s/kHz for four healthy liver volunteers, which are similar to that of a healthy liver reported by magnetic resonance elastography (5.76–7.52 m/s/kHz). It has been demonstrated that the frequency dependence of shear wave propagation can be measured.

Evaluation of Robustness of S-Transform Based Phase Velocity Estimation in Viscoelastic Phantoms and Renal Transplants.

Ultrasound shear wave elastography (SWE) methods are being used to differentiate healthy versus diseased tissue on the basis of their viscoelastic mechanical properties. Tissue viscoelasticity is often studied by analyzing shear wave phase velocity dispersion curves, which is the variation of phase velocity with frequency or wavelength. Recently, a unique approach using a generalized Stockwell transformation (GST-SFK) was proposed for the calculation of dispersion curves in viscoelastic media over expanded frequency band. In this work, the method's robustness was evaluated on data from five custom-made viscoelastic tissue-mimicking phantoms and sixty in vivo renal transplants. For each phantom, 15 shear wave motion data acquisitions were taken, while 10-13 acquisitions were acquired for renal transplants measured in the renal cortex. For each data-set mean and standard deviation (SD) of estimated phase velocity dispersion curves were studied. In addition, the viscoelastic parameters of the Zener model were examined, which were preceded by a convergence analysis. For viscoelastic phantoms scanned with a research ultrasound scanner, and for the in vivo renal transplants scanned with a clinical scanner, the decisive advantage of the GST-SFK method over the standard two-dimensional Fourier transform (2D-FT) method was shown. The GST-SFK method provided dispersion curve estimates with lower SD over a wider frequency band in comparison to the 2D-FT method. These advantages are relevant to the analysis of the mechanical properties of tissues in clinical practice to discriminate healthy from diseased tissue.

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.

Four-dimensional (4D) Ultrasound Shear Wave Elastography Using Sequential Excitation.

Current shear wave elastography methods primarily focus on 2D imaging. To explore mechanical properties of biological tissues in 3D, a four-dimensional (4D, x, y, z, t) ultrasound shear wave elastography is required. However, 4D ultrasound shear wave elastography is still challenging due to the limitation of the hardware of standard ultrasound acquisition systems. In this study, we introduce a novel method to achieve 4D shear wave elastography, named sequential-based excitation shear wave elastography (SE-SWE). This method can achieve 4D elastography implemented by a 1024-element 2D array with a standard ultrasound 256-channel system. The SE-SWE method employs sequential excitation to generate shear waves, and utilizes a 2D array, dividing it into four sub-sections, to capture shear waves across multiple planes. This process involves sequentially exciting each sub-section to capture shear waves, followed by compounding the acquired data from these subsections. The phantom studies showed strong concordance between the shear wave speeds (SWS) measured by SE-SWE and expected values, confirming the accuracy of this method and potential to differentiate tissues by stiffness. In ex vivo chicken breast experiments, SE-SWE effectively distinguished between orientations relative to muscle fibers, highlighting its ability to capture the anisotropic properties of tissues. The SE-SWE method advances shear wave elastography significantly by using a 2D array divided into four subsections and sequential excitation, achieving high-resolution volumetric imaging at 1.6mm resolution. The SE-SWE method offers a straightforward and effective approach for 3D shear volume imaging of tissue biological properties.

Evaluation of placenta in patients with gestational diabetes using shear wave elastography and superb microvascular imaging.

Gestational diabetes mellitus (GDM) is a common disease, and the placenta shows various functional and morphological changes in these patients. Superb microvascular imaging (SMI) and shear wave elastography (SWE) are innovative ultrasound (US) methods that provide detailed information about tissue vascularization and elasticity. To evaluate placental changes in patients with GDM with SMI and SWE methods. For this case-control study, 20 healthy and 20 women with GDM were included. Women at >21 weeks of pregnancy were evaluated with SMI and SWE by two independent radiologists. Mean SMI values and mean SWE values from three different region of interest-based measurements were compared between the two groups. We identified that the mean SMI and SWE value ​​of the GDM group was found to be significantly higher than that of the control group (P = 0.002, P = 0.001 respectively). Using a receiver operating characteristic curve, the cutoff value of the SMI ratio, which maximizes the prediction of the presence of GDM, was 0.1234279750 (95% confidence interval [CI] = 0.625-0.920), the SWE cut-off value was 15.5 kPa (95% CI = 0.794-0.989). We have demonstrated that evaluation with SMI and SWE might allow quantitative assessment of the morphological changes of placentas in women with GDM. We believe that the use of innovative methods such as SMI and SWE in addition to conventional US examinations in daily practice and studies will provide significant clinical benefits to patient management.

Evaluation of liver and spleen stiffness measurement with shear wave elastography in brucellosis.

Human brucellosis, which is endemic in the eastern region of Turkey, infects the reticulo-endothelial system. Acute brucellosis may cause hepatomegaly or splenomegaly. The main purpose of this study was to investigate the effectiveness of the point shear wave elastography (pSWE) method in identifying and detecting liver and spleen stiffness in acute brucellosis. This case-control study included 40 patients with acute brusellosis and 60 healthy individuals as a control group. The demographic data, abdominal ultrasonography (USG) and pSWE results of the patient and control groups were evaluated. Statistical and ROC analyses were performed. The liver pSWE value was 3.8395 ± 1.171kPa in the patient group and 1.6619 ± 0.495kPa in the control group. The spleen pSWE value was 3.2431 ± 1.803kPa in the patient group and 1.3793 ± 0.622kPa in the control group. The mean liver and spleen pSWE values were statistically significantly higher in the patient group than in the control group (p < 0.001). Cut-off values were determined as 2.524 for the liver pSWE and 1.62667 for the spleen pSWE. From the AUC values (0.959, 0.903), the diagnostic performance of liver and spleen pSWE values were seen to be excellent in distinguishing between patient and control groups. The study results showed that liver and spleen stiffness were high in acute brucellosis patients and had predictive significance above certain cut-off values. It can be considered that pSWE, which evaluates liver and spleen stiffness in acute brucellosis, may provide diagnostic benefit as a reliable, non-invasive technique.

Prospective evaluation of liver shearwave elastography measurements with 3 different technologies and same day liver biopsy in patients with chronic liver disease

BackgroundMost ultrasound-based methods for assessing liver fibrosis still need further validation with liver biopsy used as gold standard to assess their accuracy. AimsTo assess accuracy of three shear wave elastography (SWE) methods: 1) Philips Elast Point Quantification (ElastPQTM), 2) Siemens Virtual TouchTM Quantification (VTQ) acoustic radiation force impulse (ARFI), and 3) transient elastography (TE) measured by Echosens FibroscanTM. Methods160 patients underwent liver stiffness measurements (LSM) with three SWE methods immediately prior to liver biopsy. ResultsThe number of LSM required for reliable studies could be reduced to 6 for ElastPQ and to 7 for VTQ from standard recommendations of 10. Significant fibrosis and interquartile range/median (IQR/M)> 30 were independent predictors for lower reliability for detection of liver fibrosis. Ordinal logistic regression corrected for age showed that there was a significant interaction between steatosis (p = 0.008) and lobular inflammation (p = 0.04) and VTQ (ARFI) and between lobular inflammation and TE (p = 0.006). ConclusionsWe showed variations in SWE measurements using different ARFI technologies. TE and ElastPQ achieved good diagnostic performance, whereas VTQ showed lower diagnostic accuracy. The number of measurements required for reliable studies can be reduced to 6 for ElastPQ and to 7 for VTQ, which have important clinical implications.

Diagnostic performance of a new two-dimensional shear wave elastography expression using siemens ultrasound system combined with ACR TI-RADS for classification of benign and malignant thyroid nodules: A prospective multi-center study

ObjectiveThe present study aimed to evaluate the efficacy of a new two-dimensional shear wave elastography (2D-SWE) method using a Siemens ultrasound system and its combination with the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) for the differential diagnosis of benign and malignant thyroid nodules. MethodsConventional ultrasound images and 2D-SWE (E-whole-mean and E-stiffest-mean) were prospectively analyzed in 593 thyroid nodules from 543 patients. Nodules were divided into diameter (D) ≤10 mm and D > 10 mm groups and graded using ACR TI-RADS. The receiver operating characteristic curve was plotted using pathological findings as the gold standard. Diagnostic performance was compared among 2D-SWE, ACR TI-RADS, and their combination. ResultsThe area under the curve (AUC) for E-whole-mean was higher than that for E-stiffest-mean (0.858 vs. 0.790, P < 0.001), which indicated that it was the better 2D-SWE parameter for differentiating malignant nodules from benign nodules with an optimal cut-off point of 11.36 kPa. In the all-sizes group, the AUC for E-whole-mean was higher than that for ACR TI-RADS (0.858 vs. 0.808, P < 0.001). The combination of E-whole-mean and ACR TI-RADS resulted in a higher AUC (0.929 vs. 0.858 vs. 0.808, P < 0.001), sensitivity (87.0% vs. 80.3% vs. 85.2%), specificity (85.1% vs. 74.0% vs. 73.6%), accuracy (86.3% vs. 78.1% vs. 81.1%), positive predictive value (91.5% vs. 85.1% vs. 85.6%), and negative predictive value (78.0% vs. 67.0% vs. 72.9%) compared to E-whole-mean or ACR TI-RADS alone. The AUC for the combination of 2D-SWE and ACR TI-RADS was superior to that for E-whole-mean or ACR TI-RADS alone in both D ≤ 10 mm and D > 10 mm groups (P < 0.001). ConclusionAs the better 2D-SWE parameter, E-whole-mean had a higher diagnostic power than ACR TI-RADS and enhanced the diagnostic performance of ACR TI-RADS when identifying benign and malignant thyroid nodules. The combination of E-whole-mean and ACR TI-RADS improved the diagnostic performance compared to using ACR TI-RADS alone, providing a new and reliable method for the clinical diagnosis of thyroid nodules.

Shear wave imaging the active constitutive parameters of living muscles.

Shear wave elastography (SWE) of human skeletal muscles allows for measurement of muscle elastic properties in vivo and has important applications in sports medicine and for the diagnosis and treatment of muscle-related diseases. Existing methods of SWE for skeletal muscles rely on the passive constitutive theory and have so far been unable to provide constitutive parameters describing muscle active behavior. In the present paper, we overcome this limitation by proposing a SWE method for quantitative inference of active constitutive parameters of skeletal muscles in vivo. To this end, we investigate the wave motion in a skeletal muscle described by a constitutive model in which muscle active behavior has been defined by an active parameter. An analytical solution relating shear wave velocities to both passive and active material parameters of muscles is derived, based upon which an inverse approach has been developed to evaluate these parameters. To demonstrate the usefulness of the reported method, in vivo experiments were carried out on 10 volunteers to obtain constitutive parameters, particularly those describing active deformation behaviors of living muscles. The results reveal that the active material parameter of skeletal muscles varies with warm-up, fatigue and rest. STATEMENT OF SIGNIFICANCE: Existing shear wave elastography methods are limited to imaging the passive parameters of muscles. This limitation is addressed in the present paper by developing a method to image the active constitutive parameter of living muscles using shear waves. We derived an analytical solution demonstrating the relationship between constitutive parameters of living muscles and shear waves. Relying on the analytical solution, we proposed an inverse method to infer active parameter of skeletal muscles. We performed in vivo experiments to demonstrate the usefulness of the theory and method; the quantitative variation of the active parameter with muscle states such as warm-up, fatigue and rest has been reported for the first time.

A single-center, retrospective, cross-sectional study comparing the number of non-diagnostic measurements ratio in the pSWE and SSI ultrasound elastography methods.

The point shear wave elastography and supersonic shear imaging methods were compared regarding incorrect measurements during the liver examinations. A report-based, single-center, retrospective analysis of 425 liver elastography examinations was performed. A lower success ratio was observed for the point shear wave elastography method, as well as the older and obese patients pre-dominated in non-diagnostic studies. In our center experience, it is easier to obtain diagnostic data using the supersonic shear imaging method. However, further investigation of the subject is needed.

A Case-Control Study of 40 Patients with Piriformis Muscle Syndrome to Evaluate Diagnostic Findings Using Two-Dimensional Ultrasound and Shear Wave Elastography.

BACKGROUND Piriformis muscle syndrome (PMS) is a neuropathy caused by compression of the sciatic nerve by the piriformis muscle. This case-control study included 40 patients with PMS and aimed to evaluate the diagnostic findings using two-dimensional ultrasound and shear wave elastography (SWE), as non-invasive and cost-effective diagnostic methods. MATERIAL AND METHODS In order to evaluate the value of two-dimensional ultrasound diagnosis, a new imaging technique called shear wave elastography (SWE) was used in the screening of PMS, with a total of 40 PMS patients and 40 healthy individuals participating in our study. We analyzed the correlation and area under the curve (AUC) of changes in thickness (mm) and Young's modulus (kpa) of the bilateral piriformis muscle (PM). RESULTS We found that PM thickness and Young's modulus on the lesion sides were significantly higher in PMS patients than in controls (P<0.05). Also, we determined that there was a positive correlation between PM thickness and Young's modulus (r=0.454, P<0.05). Using two-dimensional ultrasonic diagnosis and the SWE technique, a specificity of 95.8% and sensitivity of 78.8% were demonstrated in the clinical diagnosis of PM. CONCLUSIONS Two-dimensional ultrasound with SWE technology has demonstrated its superior sensitivity and specificity in diagnosing PMS in the clinic.

EVALUATION OF LIVER ELASTICITY USING pSWE AND 2D-SWE TECHNIQUES IN HEALTHY CHILDREN

Objective&#x0D; Shear wave elastography (SWE) is a new&#x0D; ultrasonography technique that can non-invasively&#x0D; evaluate liver stiffness. The efficacy of SWE in adults&#x0D; has been demonstrated by numerous studies, but&#x0D; there are few SWE studies of pediatric groups. Since&#x0D; the liver stiffness values (LSV) vary according to the&#x0D; device and the SWE method used, standard reference&#x0D; values have not been established as yet. The aim of&#x0D; this study was to establish the reference values of&#x0D; normal liver stiffness in healthy children according to&#x0D; the two SWE methods.&#x0D; Materials and Method&#x0D; Liver stiffness values were measured using the two&#x0D; different SWE methods of point SWE (pSWE) and&#x0D; 2-dimensional SWE (2D-SWE) in 107 healthy children&#x0D; aged 8-18 years with no liver disease. The pSWE&#x0D; (EPQ) and 2D-SWE (EQI) measurements were taken&#x0D; in one session on the same device (Philips Epiq Elite)&#x0D; and after at least 4 hours of fasting. The effects on&#x0D; liver elasticity values were investigated of gender,&#x0D; age, body mass index (BMI), some biochemical&#x0D; markers (such as fasting blood glucose, aspartate&#x0D; aminotransferase (AST), alanine aminotransferase&#x0D; (ALT), albumin, platelet, INR) and liver size.&#x0D; Results&#x0D; The mean LSV was 4.04±0.84kPa ((95% confidence&#x0D; interval (CI):3.67-4.42)) on pSWE and 4.41±0.71kPa&#x0D; (95% CI:4.09-4.72) on 2D-SWE. The upper limit LSVs&#x0D; were found to be 4.42kPa and 4.72kPa, respectively.&#x0D; The LSVs measured on 2D-SWE were found to be&#x0D; higher than on pSWE ((median; min-max, 4.34kPa;&#x0D; 2.82-6kPa and 3.86kPa; 2.55–5.78, respectively,&#x0D; (r=0.59, p

Efficacy of Ultrasound Shear Wave Elastography in the Diagnosis of Salivary Gland Tumors

Diagnostic accuracy of fine-needle aspiration cytology (FNAC) as the ability to discriminate between the target condition and health in the evaluation of salivary gland tumors is not perfected yet and false-negative results are possible. The purpose of the present study was to measure and compare the diagnostic accuracy of FNAC performed with conventional B-mode ultrasound and ultrasound with shear wave elastography (SWE) FNAC navigation. The investigators implemented a single-blind randomized study (sealed envelope method). The study population was composed of all patients presenting for evaluation and management of suspected benign or malignant tumors of the major salivary glands between July 2013 and December 2020. The involvement of SWE navigation was the primary predictor variable affecting FNA targeting. The method involved analysis of redistribution of SWE values within the affected gland expressed in kilopascals (kPa) and the four-point ES1 (soft tissue) to ES4 (stiff) scoring. The primary outcome variable was the success in obtaining diagnostic tissue resulting in a histologically confirmed FNAC diagnosis and coded as yes/no. Age and sex of the patients and topographical locations of lesions were covariates. Descriptive and bivariate statistics were computed and the P value was set at .05. The sample included 132 subjects (male/female 59/73; mean age 54±11years; 144 tumors). SWE+Group (n=66) consisted of patients presurgically diagnosed with salivary tumors SWE-guided FNAC and SWE- Group (n=66) was diagnosed with tumors by conventional ultrasound-(B-mode)-guided FNAC. The SWE-guided FNAC statistically significantly reduced the incidence of false-negative results (n=0; P=.001) and nondiagnostic cases (n=3 SWE FNAC vs n=7 B-mode US FNAC; P=.04). For SWE+Group, the FNAC diagnosis was confirmed by postsurgical histology in 95.5% with 91.0% sensitivity (confidence interval [CI] 0.62 to 0.97) and 84.4% specificity (CI 0.58 to 0.96). For SWE- Group, 81.8% confirmation was obtained (P=.05) with 82.3% sensitivity (CI 0.54 to 0.90) and 74.0% specificity. SWE can increase success in obtaining diagnostic tissue when used for FNAC navigation purposes. We suggest combining both SWE and standard B-mode US methods when the FNAC procedure is performed.

Association between shear wave liver elastography and fibrosis index in chronic viral hepatitis B patients

Background: Chronic viral hepatitis B causes chronic inflammatory process, hepatocyte damage, progressive fibrosis, and irreversible liver damage, leading to high morbidity. There are two methods of diagnosing liver fibrosis, invasive (biopsy) and non-invasive, including radiological examination using the elastography method and hematological examination. This study aims to determine the relationship between the elasticity of liver parenchyma using the Shear Wave Elastography (SWE) method and fibrosis index in chronic viral hepatitis B patients. Methods: This research is a cross-sectional study using 68 samples that met the inclusion criteria. The 2D-SWE examination was blindly performed by two observers using a convex transducer probe with frequencies ranging from 1.2 to 6 MHz. Data were analyzed using SPSS version 20.0 for Windows. Results: In our study, there was a significant moderate positive correlation between the elasticity of liver parenchyma and the fibrosis index performed by both observers (r=0.52; p &lt; 0.001). After controlling confounding variables, a higher correction was obtained (r=0.61), suggesting a change from moderate to strong correlation (p&lt;0.05). Conclusion: There was a positive and significant correlation between the elasticity of liver parenchyma and fibrosis index.

THE STRUCTURAL AND FUNCTIONAL STATE OF THE PANCREAS AND LIVER IN CHRONIC PANCREATITIS IN COMBINATION WITH CHRONIC VIRAL HEPATITIS C DEPENDING ON THE INDEX OF THE SURVEY ACCORDING TO THE INTERNATIONAL CAGE QUESTIONNAIRE.

The aim: To conduct a comparative analysis of parameters of the structural and functional state of the liver and pancreas in patients with chronic pancreatitis in comorbidity with treated etiologically chronic viral hepatitis C, depending on the results of testing according to the international CAGE questionnaire. Materials and methods: 100 ambulatory patients with CP with concomitant HCV, treated etiotropically, were examined. All patients were examined ac-cording to generally accepted algorithms. To establish the role of alcohol on the formation of CP and the condition of patients with treated HCV, latent craving for alcohol was verified using the international CAGE questionnaire. The study of the density of the liver parenchyma and the liver of the patients was carried out not only according to the ultrasound data in the B-mode, but also with the simultaneous measurement of the shear wave elastography (SWE) method on the Ultima PA scanning ultrasound device with the further determination of the median of the parameters, which characterizes the stiffness in kilopascals (kPa). Determination of the presence and depth of pancreatic exocrine insufficiency (PEI) was carried out by the content of fecal elastase-1 (FE-1), which was determined by the enzyme immunoassay method. Results: Screening-testing of patients with CP on the background of etiotropically treated HCV using the CAGE scale made it possible to state that 65.0% of such patients had a hidden craving for alcohol, and 21.0% of this cohort were women, which needs to be taken into account in the management of such patients. It has been proven that in the group of patients with CAGE≥2.0, the level of functional and structural changes in the liver and liver was significantly more severe (according to the deepening of the PEI, a decrease in fecal α-elastase by 13.01%, according to an increase in the total index of the coprogram by 15.11% and the total US-indicator of the pancreas structure by 28.06%, and the total US-indicator of the liver structure - by 40.68% (p<0.05) and corresponded to the average degree of severity of the process in panceas according to the criteria of the Marseille-Cambridge classification, and in the group with CAGE<2.0 - only a mild degree. Conclusions: The negative effect of the factor of increased alcohol use according to CAGE was proven by increasing the density of the echostructure of the liver by 5.73% (p<0.05), and the liver by 5.16% (p<0.05). According to the results of the correlation analysis of the dependence of the structural state of the liver and PW of the studied patients on the value of the CAGE scale, which was R=0.713, p<0.05, and R=0.686, p<0.05, respectively, it was established that there is a strong direct dependence of the structural state of the liver and PW from the value of the CAGE questionnaire, which proved an independent, reliably significant role of alcohol consumption for patients with a comorbid course of CP and HCV.

Evaluation of Accuracy of Shear Wave Elastography and Superb Microvascular Imaging Methods in Diagnosis of Piriformis Syndrome: A Preliminary Study.

Piriformis syndrome is a neuromuscular disease resulting from sciatic nerve compression caused by an abnormal condition in the piriformis muscle. Superb microvascular imaging (SMI) is a new ultrasound imaging technique that visualizes low-velocity and small-diameter blood vessel flow. In our prospectively designed study, we aimed to evaluate the accuracy of diagnosis of piriformis syndrome with innovative methods such as shear wave elastography (SWE) and SMI. Thirty-two patients diagnosed with unilateral piriformis syndrome were accepted to the statistical stage. The side without symptoms was considered the "unaffected side." Bilateral piriformis muscles were examined by ultrasonography. Muscle thickness was determined on gray scale, stiffness on SWE and vascularity characteristics on power Doppler and SMI by two independent radiologists. Piriformis muscle stiffness on the non-pathological (unaffected) side was measured by SWE as 18.27 ± 7.301 kPa, and the mean stiffness on the pathological side was 29.70 ± 10.095 kPa. Pathological side muscle stiffness was significantly higher (p < 0.05). Using innovative methods such as SWE and SMI in addition to conventional ultrasonography as much as possible in our daily practice and research helps us in making the correct diagnosis in piriformis syndrome.