Elastography can be used as a diagnostic method for quantitative characterization of tissue hardness information and thus,differential changes in pathophysiological states of tissues.In this study,we propose a new met...Elastography can be used as a diagnostic method for quantitative characterization of tissue hardness information and thus,differential changes in pathophysiological states of tissues.In this study,we propose a new method for shear wave elastography(SWE)based on laser-excited shear wave,called photoacoustic shear wave elastography(PASWE),which combines photoacoustic(PA)technology with ultrafast ultrasound imaging.By using a focused laser to excite shear waves and ultrafast ultrasonic imaging for detection,high-frequency excitation of shear waves and noncontact elastic imaging can be realized.The laser can stimulate the tissue with the light absorption characteristic to produce the thermal expansion,thus producing the shear wave.The frequency of shear wave induced by laser is higher and the frequency band is wider.By tracking the propagation of shear wave,Young’s modulus of tissue is reconstructed in the whole shear wave propagation region to further evaluate the elastic information of tissue.The feasibility of the method is verified by experiments.Compared with the experimental results of supersonic shear imaging(SSI),it is proved that the method can be used for quantitative elastic imaging of the phantoms.In addition,compared with the SSI method,this method can realize the noncontact excitation of the shear wave,and the frequency of the shear wave excited by the laser is higher than that of the acoustic radiation force(ARF),so the spatial resolution is higher.Compared to the traditional PA elastic imaging method,this method can obtain a larger imaging depth under the premise of ensuring the imaging resolution,and it has potential application value in the clinical diagnosis of diseases requiring noncontact quantitative elasticity.展开更多
BACKGROUND Real-time shear wave elastography(SWE)is a non-invasive imaging technique used to measure tissue stiffness by generating and tracking shear waves in real time.This advanced ultrasound-based method provides ...BACKGROUND Real-time shear wave elastography(SWE)is a non-invasive imaging technique used to measure tissue stiffness by generating and tracking shear waves in real time.This advanced ultrasound-based method provides quantitative information regarding tissue elasticity,offering valuable insights into the mechanical properties of biological tissues.However,the application of real-time SWE in the musculoskeletal system and sports medicine has not been extensively studied.AIM To explore the practical value of real-time SWE for assessing Achilles tendon hardness in older adults.METHODS A total of 60 participants were enrolled in the present study,and differences in the elastic moduli of the bilateral Achilles tendons were compared among the following categories:(1)Age:55-60,60-65,and 65-70-years-old;(2)Sex:Male and female;(3)Laterality:Left and right sides;(4)Tendon state:Relaxed and tense state;and(5)Tendon segment:Proximal,middle,and distal.RESULTS There were no significant differences in the elastic moduli of the bilateral Achilles tendons when comparing by age or sex(P>0.05).There were,however,significant differences when comparing by tendon side,state,or segment(P<0.05).CONCLUSION Real-time SWE plays a significant role compared to other examination methods in the evaluation of Achilles tendon hardness in older adults.展开更多
BACKGROUND Supraspinatus tendinitis recurs easily after treatment.One of the main reasons is the lack of objective tools for the efficacy evaluation.Shear wave elastography(SWE)can quantitatively analyze the tissue el...BACKGROUND Supraspinatus tendinitis recurs easily after treatment.One of the main reasons is the lack of objective tools for the efficacy evaluation.Shear wave elastography(SWE)can quantitatively analyze the tissue elasticity of region of interest by measuring the Young’s modulus(YM)value.AIM To explore the role of SWE in the efficacy and prognostic evaluation of supraspinatus tendinitis.METHODS Eighty-seven patients with supraspinatus tendinitis treated in Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences were recruited.Another 30 healthy volunteers were enrolled as the control group.The visual analogue scale(VAS)and Constant-Murley Score(CMS)were recorded before treatment.All participants were scanned by SWE scan,and the YM value of the region of interest were recorded.Spearman correlation analysis was performed on YM values with VAS and CMS.Univariate repeated measures analysis of variance was used to calculate the changing trend of VAS,CMS and SWE under different treatment courses.After treatment,the patients were further grouped based on who achieved significantly effective and curative treatment.The patients in the continued treatment group continued to receive treatment according to the YM value,and the remaining patients who stopped receiving treatment were included in the stopped treatment group.All patients were followed up for 1 year,and the difference in recurrence rates between the continued treatment group and the stopped treatment group were compared.RESULTS The SWE images of supraspinatus muscle in healthy volunteers were mainly blue,while those of patients with supraspinatus tendinitis showed regional red and green areas.The average YM value of the supraspinatus muscle in healthy volunteers was 26.12±4.03 kPa.The average YM value of patients with supraspinatus muscle was greater than that of healthy volunteers(average YM=60.61±11.53 kPa,t=26.344,P<0.001).The YM value was positively correlated with VAS(r=0.564,P<0.001)and negatively correlated with CMS(r=-0.411,P<0.001).The changes of VAS and CMS were the most obvious in course 1 and then decreased gradually.The degree of change in YM values was similar in different courses.After a 1-year follow-up,the cumulative relapse-free rate in the continued treatment group was 91.43%,which was significantly higher than that in the stopped treatment group(64.71%,X2=7.379,P=0.007).CONCLUSION SWE can objectively indicate the severity of supraspinatus tendinitis.Using the YM value as a criterion for curative effect may reduce the recurrence rate.展开更多
Young′s Modulus of concrete is studied on the basis of triaxial compressive experiments. The authors proposed two empirical equations to calculate its static Young′s modulus and dynamic Young′s modulus when dynamic...Young′s Modulus of concrete is studied on the basis of triaxial compressive experiments. The authors proposed two empirical equations to calculate its static Young′s modulus and dynamic Young′s modulus when dynamic Poisson ratio μ d varies nearby 0.20.P wave velocity and elastic modulus have the same varying tendency as letter N. μ,μ d decrease with the increase of loading rate and μ d has a great effect on the parameters E d and E D.展开更多
In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, struct...In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min^(-1), which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp^3 bond content increases firstly up to the maximum(20%) at 10 sccm of N_2 flow rate, and then decreases with further increase in the N_2 flow rate. The maximum Young's modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N_2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010.展开更多
Carbon nanotube is a novel and more explored material. In this paper, ultrasonic acoustic velocity of the carbon nanotube has been calculated along unique axis at room temperature. For the evaluations of ultrasonic pr...Carbon nanotube is a novel and more explored material. In this paper, ultrasonic acoustic velocity of the carbon nanotube has been calculated along unique axis at room temperature. For the evaluations of ultrasonic properties, second and third-order elastic constants have been computed from Lennard-Jones interaction potential. Attenuation of ultrasonic waves due to phonon-phonon interaction is predominant over thermoelastic loss. Carbon nanotube shows the unique behavior with the chiral number. Chiral number not only affect the band gap and tube radius of the carbon nanotube but also affect the mechanical properties like stiffness, bulk modulus, shear modulus of the tube. The peculiar behavior is obtained at 55°. Due to their least thermal relaxation time and highest Debye average velocity. Results are also compared with other hexagonal metallic materials which present in periods and group of the periodic table. They show the optimum behavior with other hexagonal materials.展开更多
目的:探讨实时剪切波弹性成像(shear wave elastography,SWE)在K-TIRADS 3-5类甲状腺结节诊断中的应用价值。方法:回顾性分析K-TIRADS 3-5类之间的甲状腺手术患者,探讨实时SWE技术在其中的诊断价值,筛选出效能最佳的定量弹性指标,得出...目的:探讨实时剪切波弹性成像(shear wave elastography,SWE)在K-TIRADS 3-5类甲状腺结节诊断中的应用价值。方法:回顾性分析K-TIRADS 3-5类之间的甲状腺手术患者,探讨实时SWE技术在其中的诊断价值,筛选出效能最佳的定量弹性指标,得出诊断界值。结果:入组244例患者289个结节,其中恶性结节170个,良性结节119个。结节病灶区的杨氏模量最大值E max 是用于鉴别结节性质效能最佳的指标,AUC为0.764, P <0.001,且E max =52.7 kPa时鉴别K-TIRADS 3-5类结节良恶性的敏感度、特异度分别为75.3%、73.1%。结论:实时SWE技术可用于K-TIRADS 3-5类甲状腺结节的鉴别,E max 是诊断效能最佳的定量弹性指标。展开更多
目的比较阻力指数(RI)及弹性模量值在乳腺BI-RADS分类中的诊断效能。方法回顾性分析广东省第二中医院2017年10月至2018年4月经手术病理证实的65例患者的临床资料,共包括70个病灶,上述病灶在术前均进行了彩色多普勒检查及剪切波弹性成像(...目的比较阻力指数(RI)及弹性模量值在乳腺BI-RADS分类中的诊断效能。方法回顾性分析广东省第二中医院2017年10月至2018年4月经手术病理证实的65例患者的临床资料,共包括70个病灶,上述病灶在术前均进行了彩色多普勒检查及剪切波弹性成像(SWE)弹性模量值测定。分别以病灶内部血流的RI≥0.70及最大弹性模量值≥80 k Pa为界点,把病灶分类为BI-RADS 4类以上;以病理诊断结果为金标准,对比分析RI值及弹性模量值在乳腺BI-RADS分类中的诊断效能。结果 70个病灶中良性病灶39个,恶性病灶31个。单用RI值≥0.70分类BI-RADS 4类以上的敏感性为87.8%,特异性为84.0%;单用最大弹性模量值≥80 k Pa分类BI-RADS 4类以上的敏感性为88.1%,特异性为83.5%。结果显示,RI值及弹性模量值方法的诊断敏感性和特异性比较差异均无统计学意义(P>0.05)。结论 RI值及弹性模量值在乳腺BI-RADS分类中的诊断效能相当。展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFC2402400)the National Natural Science Foundation of China(Grant No.62275062)and Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology(Grant No.2020B121201010-4).
文摘Elastography can be used as a diagnostic method for quantitative characterization of tissue hardness information and thus,differential changes in pathophysiological states of tissues.In this study,we propose a new method for shear wave elastography(SWE)based on laser-excited shear wave,called photoacoustic shear wave elastography(PASWE),which combines photoacoustic(PA)technology with ultrafast ultrasound imaging.By using a focused laser to excite shear waves and ultrafast ultrasonic imaging for detection,high-frequency excitation of shear waves and noncontact elastic imaging can be realized.The laser can stimulate the tissue with the light absorption characteristic to produce the thermal expansion,thus producing the shear wave.The frequency of shear wave induced by laser is higher and the frequency band is wider.By tracking the propagation of shear wave,Young’s modulus of tissue is reconstructed in the whole shear wave propagation region to further evaluate the elastic information of tissue.The feasibility of the method is verified by experiments.Compared with the experimental results of supersonic shear imaging(SSI),it is proved that the method can be used for quantitative elastic imaging of the phantoms.In addition,compared with the SSI method,this method can realize the noncontact excitation of the shear wave,and the frequency of the shear wave excited by the laser is higher than that of the acoustic radiation force(ARF),so the spatial resolution is higher.Compared to the traditional PA elastic imaging method,this method can obtain a larger imaging depth under the premise of ensuring the imaging resolution,and it has potential application value in the clinical diagnosis of diseases requiring noncontact quantitative elasticity.
基金Supported by Sichuan Orthopaedic Hospital Research Project,No.2019MS02.
文摘BACKGROUND Real-time shear wave elastography(SWE)is a non-invasive imaging technique used to measure tissue stiffness by generating and tracking shear waves in real time.This advanced ultrasound-based method provides quantitative information regarding tissue elasticity,offering valuable insights into the mechanical properties of biological tissues.However,the application of real-time SWE in the musculoskeletal system and sports medicine has not been extensively studied.AIM To explore the practical value of real-time SWE for assessing Achilles tendon hardness in older adults.METHODS A total of 60 participants were enrolled in the present study,and differences in the elastic moduli of the bilateral Achilles tendons were compared among the following categories:(1)Age:55-60,60-65,and 65-70-years-old;(2)Sex:Male and female;(3)Laterality:Left and right sides;(4)Tendon state:Relaxed and tense state;and(5)Tendon segment:Proximal,middle,and distal.RESULTS There were no significant differences in the elastic moduli of the bilateral Achilles tendons when comparing by age or sex(P>0.05).There were,however,significant differences when comparing by tendon side,state,or segment(P<0.05).CONCLUSION Real-time SWE plays a significant role compared to other examination methods in the evaluation of Achilles tendon hardness in older adults.
基金Medical Guidance Project of Shanghai Science and Technology Commission,No.134119b2300Key Medical Discipline of Jiading District,Shanghai,No.2017ZD04.
文摘BACKGROUND Supraspinatus tendinitis recurs easily after treatment.One of the main reasons is the lack of objective tools for the efficacy evaluation.Shear wave elastography(SWE)can quantitatively analyze the tissue elasticity of region of interest by measuring the Young’s modulus(YM)value.AIM To explore the role of SWE in the efficacy and prognostic evaluation of supraspinatus tendinitis.METHODS Eighty-seven patients with supraspinatus tendinitis treated in Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences were recruited.Another 30 healthy volunteers were enrolled as the control group.The visual analogue scale(VAS)and Constant-Murley Score(CMS)were recorded before treatment.All participants were scanned by SWE scan,and the YM value of the region of interest were recorded.Spearman correlation analysis was performed on YM values with VAS and CMS.Univariate repeated measures analysis of variance was used to calculate the changing trend of VAS,CMS and SWE under different treatment courses.After treatment,the patients were further grouped based on who achieved significantly effective and curative treatment.The patients in the continued treatment group continued to receive treatment according to the YM value,and the remaining patients who stopped receiving treatment were included in the stopped treatment group.All patients were followed up for 1 year,and the difference in recurrence rates between the continued treatment group and the stopped treatment group were compared.RESULTS The SWE images of supraspinatus muscle in healthy volunteers were mainly blue,while those of patients with supraspinatus tendinitis showed regional red and green areas.The average YM value of the supraspinatus muscle in healthy volunteers was 26.12±4.03 kPa.The average YM value of patients with supraspinatus muscle was greater than that of healthy volunteers(average YM=60.61±11.53 kPa,t=26.344,P<0.001).The YM value was positively correlated with VAS(r=0.564,P<0.001)and negatively correlated with CMS(r=-0.411,P<0.001).The changes of VAS and CMS were the most obvious in course 1 and then decreased gradually.The degree of change in YM values was similar in different courses.After a 1-year follow-up,the cumulative relapse-free rate in the continued treatment group was 91.43%,which was significantly higher than that in the stopped treatment group(64.71%,X2=7.379,P=0.007).CONCLUSION SWE can objectively indicate the severity of supraspinatus tendinitis.Using the YM value as a criterion for curative effect may reduce the recurrence rate.
文摘Young′s Modulus of concrete is studied on the basis of triaxial compressive experiments. The authors proposed two empirical equations to calculate its static Young′s modulus and dynamic Young′s modulus when dynamic Poisson ratio μ d varies nearby 0.20.P wave velocity and elastic modulus have the same varying tendency as letter N. μ,μ d decrease with the increase of loading rate and μ d has a great effect on the parameters E d and E D.
基金supported by the National Magnetic Confinement Fusion Science Program of China (Grant Nos. 2014GB106005 and 2014GB106000)National Natural Science Foundation of China (Nos. 11505123,11435009,11375126)Project funded by China Postdoctoral Science Foundation (No. 156455)
文摘In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min^(-1), which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp^3 bond content increases firstly up to the maximum(20%) at 10 sccm of N_2 flow rate, and then decreases with further increase in the N_2 flow rate. The maximum Young's modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N_2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010.
文摘Carbon nanotube is a novel and more explored material. In this paper, ultrasonic acoustic velocity of the carbon nanotube has been calculated along unique axis at room temperature. For the evaluations of ultrasonic properties, second and third-order elastic constants have been computed from Lennard-Jones interaction potential. Attenuation of ultrasonic waves due to phonon-phonon interaction is predominant over thermoelastic loss. Carbon nanotube shows the unique behavior with the chiral number. Chiral number not only affect the band gap and tube radius of the carbon nanotube but also affect the mechanical properties like stiffness, bulk modulus, shear modulus of the tube. The peculiar behavior is obtained at 55°. Due to their least thermal relaxation time and highest Debye average velocity. Results are also compared with other hexagonal metallic materials which present in periods and group of the periodic table. They show the optimum behavior with other hexagonal materials.
文摘目的:探讨实时剪切波弹性成像(shear wave elastography,SWE)在K-TIRADS 3-5类甲状腺结节诊断中的应用价值。方法:回顾性分析K-TIRADS 3-5类之间的甲状腺手术患者,探讨实时SWE技术在其中的诊断价值,筛选出效能最佳的定量弹性指标,得出诊断界值。结果:入组244例患者289个结节,其中恶性结节170个,良性结节119个。结节病灶区的杨氏模量最大值E max 是用于鉴别结节性质效能最佳的指标,AUC为0.764, P <0.001,且E max =52.7 kPa时鉴别K-TIRADS 3-5类结节良恶性的敏感度、特异度分别为75.3%、73.1%。结论:实时SWE技术可用于K-TIRADS 3-5类甲状腺结节的鉴别,E max 是诊断效能最佳的定量弹性指标。
文摘目的比较阻力指数(RI)及弹性模量值在乳腺BI-RADS分类中的诊断效能。方法回顾性分析广东省第二中医院2017年10月至2018年4月经手术病理证实的65例患者的临床资料,共包括70个病灶,上述病灶在术前均进行了彩色多普勒检查及剪切波弹性成像(SWE)弹性模量值测定。分别以病灶内部血流的RI≥0.70及最大弹性模量值≥80 k Pa为界点,把病灶分类为BI-RADS 4类以上;以病理诊断结果为金标准,对比分析RI值及弹性模量值在乳腺BI-RADS分类中的诊断效能。结果 70个病灶中良性病灶39个,恶性病灶31个。单用RI值≥0.70分类BI-RADS 4类以上的敏感性为87.8%,特异性为84.0%;单用最大弹性模量值≥80 k Pa分类BI-RADS 4类以上的敏感性为88.1%,特异性为83.5%。结果显示,RI值及弹性模量值方法的诊断敏感性和特异性比较差异均无统计学意义(P>0.05)。结论 RI值及弹性模量值在乳腺BI-RADS分类中的诊断效能相当。
