The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters...The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters or characterize materials properties. In order to reduce the measuring time, a Mach–Zehnder interferometer, a full field measuring tool,was preferred in this paper. The ultrasonic wave was produced on the K9 glass surface by a Q-switched Nd:YAG laser absorbed in a liquid layer. The interferograms were then taken at various delay times by a CCD camera after single pulse induced laser ultrasonic waves. Ultrasonic waves in the K9 glass can be observed from interferogram images. The results provide an understanding of laser ultrasound propagation in K9 glass in the lifetime.展开更多
The laser generated ultrasound in solids in a thermoelastic regime is studied by solving thermoelastic wave equations. Analytic expressions of two-dimensional far-field ultrasonic displacements including the effects o...The laser generated ultrasound in solids in a thermoelastic regime is studied by solving thermoelastic wave equations. Analytic expressions of two-dimensional far-field ultrasonic displacements including the effects of thermal diffusion and optical penetration were obtained by means of the integral transform method. The meaning of the expressions is discussed. The effects of optical absorption coefficient on the directivity of laser generated ultrasound in non-metallic solids are also discussed. The directivity patterns of both longitudinal waves and shear waves are presented.展开更多
Based on the finite element method,the angled surface defects have been investigated by using the laser generated surface acoustic wave(SAW).The feature of laser generated SAW interaction with the angled defect is ana...Based on the finite element method,the angled surface defects have been investigated by using the laser generated surface acoustic wave(SAW).The feature of laser generated SAW interaction with the angled defect is analyzed in time and frequency domains.An increase in the amplitude of SAW at the edge of the defect is observed,and the spectral feature is angle dependent.With the angle decreasing from 120°to 30°,the maximum amplitude of frequency spectrum of SAW increases gradually.The corresponding experimental results verify the feasibility of numerical analyses and reach a good agreement with simulation results.展开更多
目的:分析彩色多普勒超声在双波长激光治疗婴幼儿血管瘤的应用价值。方法:回顾性分析2021年3月至2023年3月收治的血管瘤患者临床资料,所有患者在行Cynergy双波长激光治疗前均接受彩色多普勒超声检查,根据不同的血流信号和皮损深度,观察...目的:分析彩色多普勒超声在双波长激光治疗婴幼儿血管瘤的应用价值。方法:回顾性分析2021年3月至2023年3月收治的血管瘤患者临床资料,所有患者在行Cynergy双波长激光治疗前均接受彩色多普勒超声检查,根据不同的血流信号和皮损深度,观察治疗效果及并发症发生情况。结果:198例血管瘤患儿纳入分析,共计212处皮损,其中根据血流信号分为无血流信号73例(34.3%)、稀少血流信号76例(35.8%)、中等血流信号63例(29.9%),有效率为100%,96.1%,85.7%,三组比较差异有统计学意义(P<0.05);根据皮损深度分为<1.2 mm 69例(32.5%),1.2~3.0 mm 88例(41.5%),>3 mm 55例(26.0%),有效率为100%,94.3%,83.6%,三组比较差异有统计学意义(P<0.05);在所有纳入的患者中,有21.7%的患儿出现不良反应。结论:彩色多普勒超声在双波长激光治疗婴幼儿血管瘤中具有重要的应用价值,可以实时监测治疗过程,并帮助临床医师预估疗效。展开更多
Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinician...Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound(EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among nonmucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy(n CLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials(INSPECT, DETECT and CONTACT) are currently the reference standard for n CLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided n CLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications.展开更多
Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. ...Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. Ultrasound （US）-guided LITT （EchoLaser system） was performed at the output power of 2--4 Wattage （W） for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers （n=24）, and VX2 tumors implanted in the hind limbs of rabbits （n=24）. The ablation area was histologically determined by hematoxylin-eosin （HE） staining. Traditional US and contrast enhanced ultrasound （CEUS） were used to evaluate the treatment outcomes. The results showed： （1） In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 rain, and it extended slightly with the ablation time. （2） In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. （3） Gross examination of the liver and carcinoma showed three distinct regions： ablation cra- ter/carbonization, coagulation and congestion distributed from the center outwards. （4） Microscopy re- vealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and conges- tion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. （5） The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effec- tively guide and assess the treatment.展开更多
基金This work was supported by the National Natural Science Foundation of China(NNSFC)(Nos.61975080 and 11774176).
文摘The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters or characterize materials properties. In order to reduce the measuring time, a Mach–Zehnder interferometer, a full field measuring tool,was preferred in this paper. The ultrasonic wave was produced on the K9 glass surface by a Q-switched Nd:YAG laser absorbed in a liquid layer. The interferograms were then taken at various delay times by a CCD camera after single pulse induced laser ultrasonic waves. Ultrasonic waves in the K9 glass can be observed from interferogram images. The results provide an understanding of laser ultrasound propagation in K9 glass in the lifetime.
文摘The laser generated ultrasound in solids in a thermoelastic regime is studied by solving thermoelastic wave equations. Analytic expressions of two-dimensional far-field ultrasonic displacements including the effects of thermal diffusion and optical penetration were obtained by means of the integral transform method. The meaning of the expressions is discussed. The effects of optical absorption coefficient on the directivity of laser generated ultrasound in non-metallic solids are also discussed. The directivity patterns of both longitudinal waves and shear waves are presented.
基金supported by the National Natural Science Foundation of China(No.51505220)
文摘Based on the finite element method,the angled surface defects have been investigated by using the laser generated surface acoustic wave(SAW).The feature of laser generated SAW interaction with the angled defect is analyzed in time and frequency domains.An increase in the amplitude of SAW at the edge of the defect is observed,and the spectral feature is angle dependent.With the angle decreasing from 120°to 30°,the maximum amplitude of frequency spectrum of SAW increases gradually.The corresponding experimental results verify the feasibility of numerical analyses and reach a good agreement with simulation results.
文摘目的:分析彩色多普勒超声在双波长激光治疗婴幼儿血管瘤的应用价值。方法:回顾性分析2021年3月至2023年3月收治的血管瘤患者临床资料,所有患者在行Cynergy双波长激光治疗前均接受彩色多普勒超声检查,根据不同的血流信号和皮损深度,观察治疗效果及并发症发生情况。结果:198例血管瘤患儿纳入分析,共计212处皮损,其中根据血流信号分为无血流信号73例(34.3%)、稀少血流信号76例(35.8%)、中等血流信号63例(29.9%),有效率为100%,96.1%,85.7%,三组比较差异有统计学意义(P<0.05);根据皮损深度分为<1.2 mm 69例(32.5%),1.2~3.0 mm 88例(41.5%),>3 mm 55例(26.0%),有效率为100%,94.3%,83.6%,三组比较差异有统计学意义(P<0.05);在所有纳入的患者中,有21.7%的患儿出现不良反应。结论:彩色多普勒超声在双波长激光治疗婴幼儿血管瘤中具有重要的应用价值,可以实时监测治疗过程,并帮助临床医师预估疗效。
文摘Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound(EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among nonmucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy(n CLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials(INSPECT, DETECT and CONTACT) are currently the reference standard for n CLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided n CLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications.
基金supported by grants from the National Natural Science Foundation of China(No.81000616)the Natural Science Foundation of Hubei Province,China(No.2009cdb264 and No.2012ffb02526)
文摘Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. Ultrasound （US）-guided LITT （EchoLaser system） was performed at the output power of 2--4 Wattage （W） for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers （n=24）, and VX2 tumors implanted in the hind limbs of rabbits （n=24）. The ablation area was histologically determined by hematoxylin-eosin （HE） staining. Traditional US and contrast enhanced ultrasound （CEUS） were used to evaluate the treatment outcomes. The results showed： （1） In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 rain, and it extended slightly with the ablation time. （2） In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. （3） Gross examination of the liver and carcinoma showed three distinct regions： ablation cra- ter/carbonization, coagulation and congestion distributed from the center outwards. （4） Microscopy re- vealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and conges- tion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. （5） The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effec- tively guide and assess the treatment.
