Application of Real-time Ultrasound Elastography in Diagnosing Benign and Malignant Thyroid Solid Nodules

Objective Real-time ultrasound elastography(US-E) is a helpful tool in diagnosing thyroid nodules.This study aims to evaluate thyroid solid nodules,to establish the accuracy of US-E in providing information on the nature of these nodules,and to assess the clinical value of elasticity scores(ES) and strain ratio(SR) in differentiating thyroid solid nodules and to explore its distribution characteristics using pathological analysis as reference. Methods Traditional ultrasonography and US-E were performed on 131 thyroid solid nodules(99 benign ones and 32 malignant ones) in 120 patients(78 females and 41 males).Three radiologists evaluated the nodules based on a four-degree elasticity scoring system.The nodules were classified according to the ES as soft(ES 1-2) or hard(ES 3-4).The SR was calculated online. Results The sensitivity and specificity of the ES for thyroid cancer diagnosis were 78%and 80%,respectively.SR values > 2.9 used as a standard to distinguish benign from malignant nodules had a sensitivity of 87%and a specificity of 92%.The SR of the benign lesions was 1.64±1.37,which was significantly different from that of malignant lesions,which was 4.96±2.13(P<0.01). Conclusions Both the ES and SR were higher in malignant nodules than those in benign ones.Real-time US-E was a useful index in the differential diagnosis of thyroid solid nodules.It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence.

Real-time Shear Wave Elastography Assessment of Muscle Elasticity in Patients with Renal Failure

Objective:To explore the value of real-time elastic shear wave in evaluating muscle elasticity in patients with renal failure.Methods:50 patients with chronic renal failure from January 2019 to December 2022 were randomly selected as the experimental group,and 50 healthy patients aged 21-61 during the same period were selected as the control group,and the basic information of the patients,including age,gender,body mass index,etc.,were collected.Besides,the Young's modulus of the two groups of patients were observed and analyzed.Results:The Young's modulus values of left and right gastrocnemius muscles in the experimental group were significantly lower than those in the control group(P<0.05),and there was no statistical difference between the left and right sides of the experimental group and the control group(P>0.05).Conclusion:Real-time shear wave elastography provides a non-invasive,real-time and effective tool for the assessment of muscle elasticity in patients with renal failure.Through further research and optimization,real-time shear wave elastography will play a greater role in the prevention and treatment of patients with renal failure,improving the quality of life and prognosis of patients.

Assessment of Fibrosis during the Development of Fatty Liver in Rabbits using Real-time Shear-wave Elastography

Nonalcoholic and alcoholic rabbit models of fatty liver were established by feeding on high-fat diet and alcohol, respectively, and fatty liver stiffness at different pathological stages was as- sessed with real-time shear-wave elastography （SWE）, so as to investigate the fibrosis process during the development of fatty liver. The fatty liver stiffness of rabbit in nonalcoholic and alcoholic groups was higher than that in the control group, and that in alcohol group was higher than that in the nonalco- holic group （P〈0.01）. The elasticity modulus of liver in fatty liver rabbits of nonalcoholic and alcoholic groups showed a positive correlation with progression of liver fibrosis （P〈0.01）. Real-time SWE, as a noninvasive diagnostic method, can objectively reflect the liver stiffness change and progression of liver fibrosis during the development of fatty liver.

DEVELOPMENT OF A GENERIC ULTRASOUND VIBRO-ACOUSTIC IMAGING PLATFORM FOR TISSUE ELASTICITY AND VISCOSITY

Tissue elasticity and viscosity are always associated with pathological changes.As a new imaging method,ultrasound vibro-acoustic imaging is developed for quantitatively measuring tissue elasticity and viscosity which have important significance in early diagnosis of cancer.This paper developed an ultrasound vibro-acoustic imaging research platform mainly consisting of excitation part and detection part.The excitation transducer was focused at one location within the medium to generate harmonic vibration and shear wave propagation,and the detection transducer was applied to detect shear wave at other locations along shear wave propagation path using pulse-echo method.The received echoes were amplified,filtered,digitized and then processed by Kalman filter to estimate the vibration phase.According to the phase changes between different propagation locations,we estimated the shear wave speed,and then used it to calculate the tissue elasticity and viscosity.Preliminary phantom experiments based on this platform show results of phantom elasticity and viscosity close to literature values.Upcoming experiments are now in progress to obtain quantitative elasticity and viscosity in vitro tissue.

Correlation analysis of real-time three-dimensional ultrasound in diagnosis of left ventricular function, portal hemodynamics and severity of liver function in patients with liver cirrhosis

Objective:To analyze the correlation between real-time three-dimensional ultrasound in diagnosis of left ventricular function, portal hemodynamics and severity of liver function in patients with liver cirrhosis.Methods: 90 patients with cirrhosis admitted to our hospital from January 2017 to December 2018 were enrolled in the cirrhosis group, and the cirrhosis components were group A, B and C according to the Child-Pauh classification criteria. During the same period, 90 healthy subjects who underwent physical examination were selected as the control group;real-time three-dimensional ultrasonography was performed to examine left ventricular function and portal hemodynamic parameters;Pearson correlation was used to analyze left ventricular function, portal hemodynamics and liver. Functional severity relationship.Results: The left heart E and E/A levels in the cirrhosis group were significantly lower than those in the control group (P<0.05), and the A level was significantly higher than the control group (P<0.05). The Dpv and Q levels in the cirrhosis group were significantly higher than those in the healthy control group. The difference was statistically significant (P<0.05), and the level of Vpv was significantly lower than that of healthy controls (P<0.05). There were significant differences in E, A and E/A levels between different Child-Paugh patients (P<0.05). There were significant differences in portal hemodynamics Dpv, Vpv and Q between the different Child-Paugh grades, and the difference was statistically significant (P<0.05);left heart function E and E/A and liver function severity There was a significant negative correlation (P<0.05). There was a significant positive correlation between left cardiac function A and liver function severity (P<0.05). Portal vein hemodynamics Dpv, Vpv and QE were significantly associated with liver function severity. Positive correlation (P<0.05). Conclusion: Real-time three-dimensional ultrasound can effectively detect left ventricular function and portal hemodynamics changes in patients with cirrhosis, and left heart function, portal hemodynamics and liver function severity are significantly correlated.

Endoscopic ultrasound elastography for evaluation of lymph nodes and pancreatic masses:A multicenter study

AIM:To evaluate the ability of endoscopic ultrasound(EUS) elastography to distinguish benign from malignant pancreatic masses and lymph nodes.METHODS:A multicenter study was conducted and included 222 patients who underwent EUS examination with assessment of a pancreatic mass(n=121) or lymph node(n=101).The classification as benign or malignant,based on the real time elastography pattern,was compared with the classif ication based on the B-mode EUS images and with the fi nal diagnosis obtained by EUS-guided fi ne needle aspiration(EUS-FNA) and/or by surgical pathology.An interobserver study was performed.RESULTS:The sensitivity and specificity of EUS elastography to differentiate benign from malignant pancreatic lesions are 92.3% and 80.0%,respectively,compared to 92.3% and 68.9%,respectively,for the conventional B-mode images.The sensitivity and specificity of EUS elastography to differentiate benign from malignant lymph nodes was 91.8% and 82.5%,respectively,compared to 78.6% and 50.0%,respectively,for the B-mode images.The kappa coefficient was 0.785 for the pancreatic masses and 0.657 for the lymph nodes.CONCLUSION:EUS elastography is superior compared to conventional B-mode imaging and appears to be able to distinguish benign from malignant pancreatic masses and lymph nodes with a high sensitivity,specificity and accuracy.It might be reserved as a second line examination to help characterise pancreatic masses after negative EUS-FNA and might increase the yield of EUS-FNA for lymph nodes.

Value of shear wave elastography with maximal elasticity in differentiating benign and malignant solid focal liver lesions

BACKGROUND It is important to differentiate benign and malignant focal liver lesions(FLLs)accurately.Despite the wide use and acceptance of shear wave elastography(SWE),its value for assessing the elasticity of FLLs and differentiating benign and malignant FLLs is still investigational.Previous studies of SWE for FLLs used mean elasticity as the parameter to reflect the stiffness of FLLs.Considering the inhomogeneity of tumor stiffness,maximal elasticity(Emax)might be the suitable parameter to reflect the stiffness of FLLs and to differentiate malignant FLLs from benign ones.AIM To explore the value of SWE with Emax in differential diagnosis of solid FLLs.METHODS We included 104 solid FLLs in 95 patients and 50 healthy volunteers.All the subjects were examined using conventional ultrasound(US)and virtual touch tissue quantification(VTQ)imaging.A diagnosis of benign or malignant FLL was made using conventional US.Ten VTQ values were acquired after 10 consecutive measurements for each FLL and each normal liver,and the largest value was recorded as Emax.RESULTS There were 56 cases of malignant FLLs and 48 cases of benign FLLs in this study.Emax of malignant FLLs(3.29±0.88 m/s)was significantly higher than that of benign FLLs(1.30±0.46 m/s,P<0.01)and that of livers in healthy volunteers(1.15±0.17 m/s,P<0.01).The cut-off point of Emax was 1.945,and the area under the curve was 0.978.The sensitivity and specificity of Emax were 92.9%and 91.7%,respectively,higher(but not significantly)than those of conventional US(80.4%for sensitivity and 81.3%for specificity).Combined diagnosis of conventional US and Emax using parallel testing improved the sensitivity to 100%with specificity of 75%.CONCLUSION SWE is a convenient and easy method to obtain accurate stiffness information of solid FLLs.Emax is useful for differential diagnosis of FLLs,especially in combination with conventional US.

Micro-failure process and failure mechanism of brittle rock under uniaxial compression using continuous real-time wave velocity measurement

In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage.A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing.Based on which,the effective elastic parameters are inferred by a transverse isotropic constitutive model,and the evolutions of the crack density are inversed using a self-consistent damage model.It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack.

Real Time Ultrasound Elastography for the Differentiation of Benign and Malignant Thyroid Nodules

The purpose of this study was to evaluate the predictive value of real-time ultrasound elastography (RUE) in differentiating benign from malignant thyroid nodules, with fine needle aspiration cytology analysis as the reference standard. A total of 78 consecutive patients with thyroid nodules who were selected for fine needle aspiration biopsies were examined in this prospective study. 78 nodules in these patients were examined by conventional ultrasound, and ultrasound elastography. The final diagnosis was obtained from cytological findings. Tissue stiffness on ultrasound elastography was scored from 1 (low stiffness over the entire nodule) to 5 (high stiffness over the entire nodule and surrounding tissue). On real-time ultrasound elastography, 47 of 62 benign nodules (76%) had a score of 1 or 2, whereas 15 of 16 malignant nodules had a score of 3 to 5, with sensitivity of 93.7%, specificity of 90%, a positive predictive value of 71%, and a negative predictive value of 98%. Real-time ultrasound elastography is a promising imaging technique that is useful in the differential diagnosis of thyroid cancer. Utilization of ultrasound elastography could reduce the rate of thyroid biopsies because of its high elasticity being highly associated with benign cytology.

Real-time virtual sonography visualization and its clinical application in biliopancreatic disease

AIM:To evaluate the usefulness of real-time virtual sonography(RVS)in biliary and pancreatic diseases.METHODS:This study included 15 patients with biliary and pancreatic diseases.RVS can be used to observe an ultrasound image in real time by merging the ultrasound image with a multiplanar reconstruction computed tomography(CT)image,using pre-scanned CT volume data.The ultrasound used was EUB-8500with a convex probe EUP-C514.The RVS images were evaluated based on 3 levels,namely,excellent,good and poor,by the displacement in position.RESULTS:By combining the objectivity of CT with free scanning using RVS,it was possible to easily interpret the relationship between lesions and the surrounding organs as well as the position of vascular structures.The resulting evaluation levels of the RVS images were12 excellent(pancreatic cancer,bile duct cancer,cholecystolithiasis and cholangiocellular carcinoma)and 3 good(pancreatic cancer and gallbladder cancer).Compared with conventional B-mode ultrasonography and CT,RVS images achieved a rate of 80%superior visualization and 20%better visualization.CONCLUSION:RVS has potential usefulness in objective visualization and diagnosis in the field of biliary and pancreatic diseases.

Experimental model standardizing polyvinyl alcohol hydrogel to simulate endoscopic ultrasound and endoscopic ultrasoundelastography

BACKGROUND Endoscopic ultrasound(EUS)and endoscopic ultrasound elastography(EUS-E)simulation lessens the learning curve;however,models lack realism,diminishing competitiveness.AIM To standardize the mechanical properties of polyvinyl alcohol(PVA)hydrogel for simulating organs and digestive lesions.METHODS PVA hydrogel(Sigma Aldrich,degree of hydrolysis 99%)for simulating EUS/EUS-E lesions was investigated in Unidad de Investigación y Desarrollo Tecnológico at Hospital General de México“Dr.Eduardo Liceaga”,Mexico City.We evaluated physical,contrast,elasticity and deformation coefficient characteristics in lesions,applying Kappa’s concordance and satisfaction questionnaire(Likert 4-points).RESULTS PVA hydrogel showed stable mechanical properties.Density depended on molecular weight(MW)and concentration(C).PVA bblocks with the greatest density showed lowest tensile strength(r=-0.8,P=0.01).Lesions were EUSgraphically visible.Homogeneous and heterogeneous examples were created from PVA blocks or PVA phantoms,exceeding(MW2=146000-186000,C9=15%and C10=20%)with a density under(MW1=85000-124000,C1=7%and C2=9%).We calculated elasticity and deformation parameters of solid(blue)areas,contrasting with the norm(Kappa=0.8;high degree of satisfaction).CONCLUSION PVA hydrogels were appropriate for simulating organs and digestive lesions using EUS/EUS-E,facilitating practice and reducing risk.Repetition amplified skills,while reducing the learning curve.

3D Elastic Registration of Ultrasound Images Based on Skeleton Feature

In order to eliminate displacement and elastic deformation between images of adjacent frames in course of 3D ultrasonic image reconstruction, elastic registration based on skeleton feature was adopt in this paper. A new automatically skeleton tracking extract algorithm is presented, which can extract connected skeleton to express figure feature. Feature points of connected skeleton are extracted automatically by accounting topical curvature extreme points several times. Initial registration is processed according to barycenter of skeleton. Whereafter, elastic registration based on radial basis function are processed according to feature points of skeleton. Result of example demonstrate that according to traditional rigid registration, elastic registration based on skeleton feature retain natural difference in shape for organr s different part, and eliminate slight elastic deformation between frames caused by image obtained process simultaneously. This algorithm has a high practical value for image registration in course of 3D ultrasound image reconstruction.

NEUROCOMPUTING THEORY AND NUMERICAL SIMULATION ON ELASTICITY

A new finite element analysis principle based on neural networks is proposed. It can realize the finite element analysis in real time. The neural computation of a simple structure was simulated on digital computer, the effect of input parameters on convergent speed and precision was analyzed. Before solving a certain FE problem, the linking weight matrix of the neural net, i.e., the global stiffness matrix of the structure analyzed, must be defined. In this paper, a method which uses the BP net to compute the element stiffness matrix in real time is proposed.

Novel approach of ultrasound-guided lateral recess block for a patient with lateral recess stenosis: A case report

BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultrasound-guided Lateral recess block(LRB)are limited,this is probably because there is no recognized standard method for ultrasound scanning.This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis(LRS).CASE SUMMARY A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb.Physical examination showed ten-derness on the spinous process and paraspinal muscles from L1 to S1,extensor hallucis longus and tibialis anterior weakness(muscle strength:4-),and a positive straight leg raising test in the left lower limb(60°).Magnetic resonance imaging showed L4–L5 disc degeneration with left LRS and nerve root entrapment.Subsequently,the patient was diagnosed with LRS.This patient was treated with a novel ultrasound-guided LRB approach.The patient’s symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up.CONCLUSION This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique.Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS.

Evaluating the Efficacy of Cervical Tactile Ultrasound Technique as a Predictive Tool for Spontaneous Preterm Birth

Background: Premature cervical softening and shortening may be considered an early mechanical failure that predispose to preterm birth. Purpose: This study aims to explore the applicability of an innovative cervical tactile ultrasound approach for predicting spontaneous preterm birth (sPTB). Materials and Methods: Eligible participants were women with low-risk singleton pregnancies in their second trimester, enrolled in this prospective observational study. A Cervix Monitor (CM) device was designed with a vaginal probe comprising four tactile sensors and a single ultrasound transducer operating at 5 MHz. The probe enabled the application of controllable pressure to the external cervical surface, facilitating the acquisition of stress-strain data from both anterior and posterior cervical sectors. Gestational age at delivery was recorded and compared against cervical elasticity. Results: CM examination data were analyzed for 127 women at 240/7 - 286/7 gestational weeks. sPTB was observed in 6.3% of the cases. The preterm group exhibited a lower average cervical stress-to-strain ratio (elasticity) of 0.70 ± 0.26 kPa/mm compared to the term group’s 1.63 ± 0.65 kPa/mm with a p-value of 1.1 × 10−4. Diagnostic accuracy for predicting spontaneous preterm birth based solely on cervical elasticity data was found to be 95.0% (95% CI, 88.5 - 100.0). Conclusion: These findings suggest that measuring cervical elasticity with the designed tactile ultrasound probe has the potential to predict spontaneous preterm birth in a cost-effective manner.

Modified B-ultrasound method for measurement of antral section only to assess gastric function and guide enteral nutrition in critically ill patients

AIM To establish a modified B-ultrasound method of measuring the antral section only to assess gastric motility in healthy people,and evaluate its application in guiding enteral nutrition(EN) in critically ill patients. METHODS First,30 healthy volunteers were selected. The modified B-ultrasound method and the traditional B-ultrasound method were applied to assess gastric function. The correlation of indices of gastric function between the two groups was analyzed statistically. In addition,64 critically ill patients were selected,and the modified B-ultrasound method and the gastric juice withdrawal method were applied to guide the implementation of EN. Daily caloric value,the time required to achieve complete EN,ICU stay,hospitalization time,and serum prealbumin and albumin levels were recorded and compared between the two groups. Kaplan-Meier survival curve was used to compare the complications of EN between the two groups. RESULTS In healthy subjects,there was a good correlation among gastric emptying time,antral contraction frequency andantral motility index between the two groups(r = 0.57,0.61 and 0.54,respectively). The study on critically ill patients also revealed that a better effect of EN was achieved in the modified B-ultrasound method group,in which patients had shorter ICU stay and hospitalization time and higher levels of serum prealbumin and albumin. The Kaplan-Meier survival analysis revealed that the improved B-ultrasound method was associated with significantly fewer EN complications(P = 0.031).CONCLUSION The modified B-ultrasound method can provide a good real-time assessment of gastric function and has a better effect than the traditional method in guiding EN in critically ill patients.

State-of-the-art imaging techniques in endoscopic ultrasound

Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment,with a major clinical impact in digestive and mediastinal diseases.State-of-the-art EUS equipment now includes real-time sono-elastography,which might be useful for a better characterization of lesions and increased accuracy of differential diagnosis (for e.g.lymph nodes or focal pancreatic lesions).Contrast-enhanced EUS imaging is also available,and is already being used for the differential diagnosis of focal pancreatic masses.The recent development of low mechanical index contrast harmonic EUS imaging offers hope for improved diagnosis,staging and monitoring of anti-angiogenic treatment.Tridimensional EUS (3D-EUS) techniques can be applied to enhance the spatial understanding of EUS anatomy,especially for improved staging of tumors,obtained through a better assessment of the relationship with major surrounding vessels.Despite the progress gained through all these imaging techniques,they cannot replace cytological or histological diagnosis.However,real-time optical histological diagnosis can be achieved through the use of single-fiber confocal laser endomicroscopy techniques placed under real-time EUS-guidance through a 22G needle.Last,but not least,EUS-assisted natural orifice transluminal endoscopic surgery (NOTES) procedures offer a whole new area of imaging applications,used either for combination of NOTES peritoneoscopy and intraperitoneal EUS,but also for access of retroperitoneal organs through posterior EUS guidance.

Tactile and Ultrasound Image Fusion for Functional Assessment of the Female Pelvic Floor

Introduction: The true etiology of pelvic organ prolapse and urinary incontinence and variations observed among individuals are not entirely understood. Tactile (stress) and ultrasound (anatomy, strain) image fusion may furnish new insights into the female pelvic floor conditions. This study aimed to explore imaging performance and clinical value of vaginal tactile and ultrasound image fusion for characterization of the female pelvic floor. Methods: A novel probe with 96 tactile and 192 ultrasound transducers was designed. Women scheduled for a urogynecological visit were considered eligible for enrollment to observational study. Intravaginal tactile and ultrasound images were acquired for vaginal wall deformations at probe insertion, elevation, rotation, Valsalva maneuver, voluntary contractions, involuntary relaxation, and reflex pelvic muscle contractions. Biomechanical mapping has included tactile/ultrasound imaging and functional imaging. Results: Twenty women were successfully studied with the probe. Tactile and ultrasound images for tissues deformation as well as functional images were recorded. Tactile (stress) and ultrasound (strain) images allowed creation of stress-strain maps for the tissues of interest in absolute scale. Functional images allowed identification of active pelvic structures and their biomechanical characterization (anatomical measurements, contractive mobility and strength). Fusion of the modalities has allowed recognition and characterization of levator ani muscles (pubococcygeal, puborectal, iliococcygeal), perineum, urethral and anorectal complexes critical in prolapse and/or incontinence development. Conclusions: Vaginal tactile and ultrasound image fusion provides unique data for biomechanical characterization of the female pelvic floor. Bringing novel biomechanical characterization for critical soft tissues/structures may provide extended scientific knowledge and improve clinical practice.

Clinical efficacy of ultrasound-guided pulsed radiofrequency combined with ganglion impar block for treatment of perineal pain

BACKGROUND Ganglion impar block alone or pulsed radiofrequency alone are effective options for treating perineal pain.However,ganglion impar block combined with pulsed radiofrequency(GIB-PRF)for treating perineal pain is rare and the puncture is usually performed with X-ray or computed tomography guidance.AIM To evaluate the safety and clinical efficacy of real-time ultrasound-guided GIBPRF in treating perineal pain.METHODS Thirty patients with perineal pain were included and were treated by GIB-PRF guided by real-time ultrasound imaging between January 2015 and December 2016.Complications were recorded to observe the safety of the ultrasound-guided GIB-PRF procedure,and visual analogue scale(VAS)scores at 24 h before and after treatment and 1,3,and 6 mo later were analyzed to evaluate clinical efficacy.RESULTS Ultrasound-guided GIB-PRF was performed successfully in all patients,and no complications occurred.Compared with pretreatment scores,the VAS scores were significantly lower(P<0.05)at the four time points after treatment.The VAS scores at 1 and 3 mo were slightly lower than those at 24 h(P>0.05)and were significantly lower at 6 mo after treatment(P<0.05).There was a tendency toward lower VAS scores at 6 mo after treatment compared with those at 1 and 3 mo(P>0.05).CONCLUSION Ultrasound-guided GIB-PRF was a safe and effective way to treat perineal pain.The 6-mo short-term clinical efficacy was favorable,but the long-term outcomes need future study.

Elastic Moduli in Cadmium Selenide Doped with Chromium

Temperature dependence of elastic moduli , , and the latter for the piezo-active and non-piezo-active versions, have been measured in the interval of 4 - 180 K at 28 - 262 MHz in a CdSe: Cr2+ crystal. Anomalies below 40 K have been found for all the moduli, except . The interpretation of the results has been carried out involving the Jahn-Teller effect and relaxation between the equivalent distortions of the tetrahedral CrSe4 centers.