scholarly journals Relationship between SW velocity and muscle activation is inconsistent across different muscle types

2021 ◽  
Author(s):  
Michel Bernabei ◽  
Thomas G. Sandercock ◽  
Eric J. Perreault ◽  
Sabrina S. M. Lee
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Muscle Activation ◽  
Muscle Length ◽  
Relative Length ◽  
Pennation Angle ◽  
Ultrasound Elastography ◽  
Muscle Types ◽  
The Relationship

ABSTRACTThere is an increasing use of shear wave ultrasound elastography to quantify material properties of muscles under various conditions such as muscle length, levels of activation, in healthy and pathological muscle. However, little is known about the variability in shear wave velocity among muscles. The purpose of this study was to assess the variability of the relationship between SWV and activation across muscles with different architecture, specifically pennation angle: biceps brachii (parallel), tibialis anterior (moderately pennate), gastrocnemius (highly pennate). We tested these muscles at matching levels of activation and similar muscle lengths, relative to optimal length, to limit differences in force across muscles. Shear wave velocity-squared increased with higher levels of muscle activation (p<0.001), but the relationship between shear wave velocity-squared and activation was different across all three muscles (p<0.001). This indicates that SWV was inconsistent across muscle types, even when considering similar levels of activation and torque production. Under passive conditions, shear wave velocity-squared covaried with muscle length and was different across muscles (p<0.001), even at shortest lengths, when differences due to passive force were minimal. Variation of shear wave velocity-squared was only partially explained by changes in pennation angle during contraction (p = 0.004, R2 = 0.4). Our findings suggest that the shear wave velocity varies across muscles under passive and active conditions even when relative length is considered and that shear wave velocity may be dependent on other muscle properties, other than pennation angle, that are different between the three muscles.

Relationship between Shear Wave Velocity and Muscle Activation is Inconsistent Across Different Muscle Types

2021 ◽  
Author(s):  
Michel Bernabei ◽  
Daniel Ludvig ◽  
Thomas G. Sandercock ◽  
Eric J. Perreault ◽  
Sabrina SM Lee
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Muscle Activation ◽  
Muscle Types

Shear Strength Monitoring System Based on Measurement of Shear Wave Velocity and Moisture Content

2014 ◽  
Vol 635-637 ◽  
pp. 750-754
Author(s):  
Peng Hu ◽  
Qing Li ◽  
Yi Wei Xu ◽  
Nan Ying Shentu ◽  
Quan Yuan Peng
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Wave ◽  
Monitoring System ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Bender Elements ◽  
Strength Measurement ◽  
Soil Shear Strength ◽  
The Relationship

Expound the importance of soil shear strength measurement at mudslide hidden point to release the loss caused by the disaster, explain the relationship between shear wave velocity, moisture content and shear strength, design the shear strength monitoring system combining the shear wave velocity measured by Piezoelectric bender elements and moisture content.

scholarly journals Successful experience in the use of ultrasound elastography in the differentiating of lymphomatous and metastatic superficial lymphadenopathy

2020 ◽  
Vol 15 (2) ◽  
pp. 42-48
Author(s):  
E. V. Kovaleva ◽  
T. Yu. Danzanova ◽  
G. T. Sinyukova ◽  
E. A. Gudilina ◽  
P. I. Lepedatu ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Area Ratio ◽  
Ultrasound Elastography ◽  
Acoustic Radiation Force Impulse ◽  
Tissue Imaging ◽  
Hodgkin's Lymphomas

The objective: to evaluate the possibilities of ARFI technology (Acoustic Radiation Force Impulse), including Virtual Touch™ Tissue Imaging (VTI) and Virtual Touch™ Tissue Quantification (VTQ) for differentiation of lymphomatous and metastatic superficial lymphadenopathy.Materials and methods. The prospective study included 138 patients with enlarged superficial lymph nodes (LN). Based on a previous histological examination, patients were divided into two groups: 1st group (n = 108) – patients with non-Hodgkin’s lymphomas and Hodgkin’s lymphoma; 2nd group (n = 30) – patients with metastasis of solid tumors in superficial LN. All patients underwent ultrasound elastography of the enlarged LN using ARFI technology. In VTI study the Area Ratio parameter was evaluated, and the minimum and average values of the shear wave velocity were estimated in VTQ study.Results. According to the results of VTI study the Area Ratio parameter for enlarged LN in lymphoma (1st group) and for metastatic lymphadenopathy (2 nd group) were 1.031 ± 0.197 and 0.851 ± 0.15, respectively (p = 0.000009). The cut off value of the Area Ratio parameter was 0.901 with sensitivity, specificity and accuracy 80.6, 70.0 and 78.8 %, respectively. Minimum values of shear wave velocities for 1st and 2 nd groups were 1.980 ± 0.557 and 2.214 ± 0.367 m/s, respectively (p = 0.032). The cut off values of the average shear wave velocity in the differentiating of lymphomatous and metastatic lymphadenopathy are determined at the level of 2.00 m/s, with sensitivity of 70.0 %, specificity of 59.3 %, and accuracy of 61.6 %.Conclusion. Ultrasound elastography with ARFI technology demonstrated statistically significant differences in the Area Ratio parameter and in the minimum shear wave velocity in the enlarged superficial LN in lymphoma and with metastasis that can be used as a preliminary non-invasive differential diagnosis of enlarged superficial LN in these conditions. Moreover, the Area Ratio parameter has a statistically more significant effect on differentiating of lymphomatous and metastatic lymphadenopathy.

scholarly journals Area Covered for Shear Wave Velocity Calculation Affects the Shear Wave Velocity Values

2019 ◽  
Vol 35 (3) ◽  
pp. 182-187
Author(s):  
Amitabh Dashottar ◽  
Erin Montambault ◽  
Jeffrey R. Betz ◽  
Kevin D. Evans
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Region Of Interest ◽  
Ultrasound Elastography ◽  
Maximum Area ◽  
Shear Wave Velocities ◽  
Significant Difference ◽  
Technical Specifications ◽  
The Mean

Although ultrasound elastography is established as a reliable and valid tool for assessment of skeletal muscles, guidelines around the technical specifications, data selection, and acquisition parameters still lack consensus. One such parameter is the use of the quantification box (Q-box) that calculates the shear wave velocity/modulus, within a selected region of interest (ROI). Currently, no data compare the effect of the elastographic area within the ROI to the mean shear wave velocity calculations, using a Q-box. In this study, the mean shear wave velocity calculated over a smaller (single Q-box) ROI is compared to the mean shear wave velocity calculated over maximum area of elastogram, within a ROI. Comparison of mean shear wave velocity revealed a significant difference ( t = 2.79, P = .007) between the means calculated over maximum area of elastogram for only nonuniform elastograms. The rater agreement for the classification scheme was assessed (κ = 0.85). To prevent possible overestimation of shear wave velocities, it may be necessary to place the Q-box over the maximum elastographic area.

Effect of Anisotropy on Shear Wave Velocity in Wood

2012 ◽  
Vol 535-537 ◽  
pp. 1923-1926
Author(s):  
Jian Ping Zhou ◽  
Jin Xia Liu ◽  
Wen Yang Gao ◽  
Zhi Wen Cui ◽  
Wei Guo Lv ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Radial Direction ◽  
Rotation Angle ◽  
Wood Specimen ◽  
Shear Waves ◽  
Circular Ring ◽  
The Relationship ◽  
Intrinsic Birefringence

The velocities of shear waves propagating along radial direction of birch and elmwood specimens are measured in order to study the effect of anisotropy on shear wave velocity. The relationship between the shear wave velocity and the oscillation direction is examined by rotating an ultrasonic sensor. The results indicate that the effect of anisotropy on shear wave velocity in birch and elmwood specimens is similar to Japanese magnolia specimen. When the oscillation direction of the shear wave corresponds to the certain anisotropic direction of the wood specimen, the shear wave velocity decreases sharply and the relationship between shear wave velocity and rotation angle tends to become discontinuous. The intrinsic birefringence due to the anisotropy of birch and elmwood woods is observed. Their texture anisotropies are strong. In an isotropic nylon, on the contrary, the value of shear wave velocity was similar to a circular ring. This investigation is significant meanings in architectural and civil engineering field.

scholarly journals Эластографическая характеризация рака яичка (морфологические и технические аспекты)

2017 ◽  
pp. 25-39
Keyword(s):  
Testicular Cancer ◽  
Germ Cell ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Germ Cell Tumors ◽  
Shear Wave Elastography ◽  
Ultrasound Elastography ◽  
Nonseminomatous Germ Cell Tumors ◽  
Multiparametric Ultrasound

Проведена ультразвуковая эластографическая оценка злокачественных опухолей яичка у 31 пациента в возрасте от 19 до 65 лет. Во всех случаях было одностороннее поражение. Во всех случаях диагноз подтвержден морфологически (семинома - 18 (58,1%), эмбриональная карцинома - 5 (16,1%), смешанные герминогенные опухоли - 7 (22,6%), спермоцитарная семинома - 1 (3,2%)). Пациенты были разделены на группы в зависимости от морфологических видов опухоли (семинома (n = 18) и несеминомные герминогенные опухоли (n = 12, в 2 случаях семинома была одним из компонентов смешанной герминогенной опухоли) (1 случай спермоцитарной семиномы был исключен из этой части анализа); тератома как компонент смешанной герминогенной опухоли (n = 6) и остальные герминогенные опухоли (n = 25)). Режим эластографии сдвиговой волной использовался после предварительной серошкальной визуализации яичек на аппаратах Aplio 500 (Toshiba, Япония) и Aixplorer (Supersonic Imagine, Франция) (линейные датчики 5-14 и 4-15 МГц соответственно). Технические аспекты: различия между измерениями значений модуля Юнга в опухолях яичка на аппарате (1) Aplio 500 и аппарате (2) Aixplorer недостоверны (P = 0,95). Корреляция между значениями модуля Юнга, полученными на двух приборах, высокая (rs = 0,86, P = 0,0137). Значения модуля Юнга в опухолях яичка достоверно выше по сравнению с эхографически неизмененной паренхимой ипсилатерального яичка (P = 0,0017 для указанных сравнений на двух аппаратах) и паренхимой эхографически неизмененного контрлатерального яичка (P = 0,0017 для указанных сравнений на двух аппаратах) на фоне отсутствия достоверности различий между значениями модуля Юнга в двух яичках (неизмененные участки ипсилатерального яичка и паренхима среднего сегмента контрлатерального яичка) (P = 0,4057 и P = 0,8480 для аппаратов 1 и 2 соответственно). Морфологические аспекты (аппарат Aixplorer): медиана Emean в группе семиномы (n = 18) составила 110,3 кПа, 25-75-й процентили - 77,6-159,0 кПа, 5-95-й процентили - 16.5- 222,1 кПа, минимальное - максимальное значения - 15,3-241,4 кПа; в группе несеминомных герминогенных опухолей (n = 12) - 109,9 кПа, 83,0-129,0 кПа, 55.5- 156,8 кПа, 54,2-157,8 кПа (различия недостоверны при P=0,9325). Отсутствие достоверности различий также было определено при сравнении смешанных герминогенных опухолей, в составе которых была тератома, и остальных опухолей (P = 0,5823). Различия значений индексов жесткости (индекс жесткости 1 - отношение значений Emean в областях опухоли и эхографически неизмененной паренхимы ипсилатерального яичка, индекс жесткости 2 - отношение значений Emean в областях опухоли и паренхимы эхографически неизмененного контрлатерального яичка, индекс жесткости 3 - внутриопухолевый индекс жесткости с учетом участков с максимальной и минимальной жесткостью внутри объемного образования) у пациентов с семиномами и несеминомными герминогенными опухолями не выявлены. Ключевые слова: мультипараметрическая ультразвуковая диагностика, ультразвуковая эластография, эластография сдвиговой волной, жесткость, модуль Юнга, скорость сдвиговой волны, рак яичка, семинома, несеминомные герминогенные опухоли, multiparametric ultrasound, ultrasound elastography, shear wave elastography, stiffness, Young’s modulus, shear wave velocity, testicular cancer, seminoma, nonseminomatous germ cell tumors

scholarly journals Axial Stress Provides a Lower Bound on Shear Wave Velocity in Active and Passive Muscle

2021 ◽  
Author(s):  
Michel Bernabei ◽  
Sabrina S. M. Lee ◽  
Eric J. Perreault ◽  
Thomas G. Sandercock
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Axial Stress ◽  
Muscle Length ◽  
Muscle Stiffness ◽  
Medial Gastrocnemius ◽  
Active Muscle ◽  
Muscle Stress ◽  
Stress Dependent

ABSTRACTUltrasound shear wave elastography can be used to characterize mechanical properties of unstressed tissue by measuring shear wave velocity (SWV), which increases with increasing tissue stiffness. Measurements of SWV have often been assumed to be directly related to the stiffness of muscle. Some have also used measures of SWV to estimate stress, since muscle stiffness and stress covary during active contractions. However, few have considered the direct influence of muscle stress on SWV, independent of the stress-dependent changes in muscle stiffness, even though it is well known that stress alters shear wave propagation. The objective of this study was to determine how well the theoretical dependency of SWV on stress can account for measured changes of SWV in passive and active muscle. Data were collected from six isoflurane-anesthetized cats; three soleus muscles and three medial gastrocnemius muscles. Muscle stress and stiffness were measured directly along with SWV. Measurements were made across a range of passively and actively generated stresses, obtained by varying muscle length and activation, which was controlled by stimulating the sciatic nerve. Our results show that SWV depends primarily on the stress in a passively stretched muscle. In contrast, the SWV in active muscle is higher than would be predicted by considering only stress, presumably due to activation-dependent changes in muscle stiffness. Our results demonstrate that while SWV is sensitive to changes in muscle stress and activation, there is not a unique relationship between SWV and either of these quantities when considered in isolation.

Study on Poisson Ratio of Soil-Rock Mixture in Low Strain

2011 ◽  
Vol 90-93 ◽  
pp. 1921-1925 ◽  
Author(s):  
Xian Min Zhang ◽  
Yao Zhi Lv ◽  
Yi Ming Zhao ◽  
Yu Hui Zhang ◽  
Zhi Liao
Keyword(s):  
Water Content ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Poisson Ratio ◽  
Nonlinear Models ◽  
Absolute Error ◽  
Longitudinal Wave Velocity ◽  
Mixture Samples ◽  
The Relationship

Longitudinal wave velocity and shear wave velocity of two kinds of the soil-rock mixture samples with different stone content and water content are tested. Then the poisson ratio of the samples in Low Strain can be calculated with the method of wave velocity testing. Analyzing the relationship between poisson ratio, water content and stone content, the dualistic nonlinear models of poisson ratio, water content and stone content are established. The result of verifying is shown that the absolute error of poisson ratio is less than 0.01 and the relative error is less than 2%. The models not only can show the relationship between poisson ratio, water content and stone content but can provide the reference when changing the Rayleigh wave velocity to shear wave velocity each other.

scholarly journals Метастатическое поражение периферических лимфатических узлов при злокачественной меланоме кожи: роль эластографии сдвиговой волной

2017 ◽  
pp. 25-35
Keyword(s):  
Malignant Melanoma ◽  
Lymph Nodes ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Shear Wave Elastography ◽  
Cutaneous Malignant Melanoma ◽  
Ultrasound Elastography ◽  
Clark Level ◽  
Level Of Invasion

С января по август 2017 г. выполнены ультразвуковые исследования лимфатических узлов у 51 человека (23 мужчины и 28 женщин) в возрасте 23-86 лет с цитологически верифицированным диагнозом “злокачественная меланома кожи”. У всех пациентов заподозрены метастатические изменения в лимфатических узлах различной локализации по данным серошкальной эхографии и допплерографических методик. Исследования были выполнены на аппарате Aplio 500 (Toshiba, Япония) линейным датчиком 7-18 МГц. В первую группу вошел 21 человек с метастазами в регионарных лимфатических узлах, во вторую - 30 пациентов с гиперплазией лимфоидноретикулярной ткани. Значения модуля Юнга для метастатически измененных лимфатических узлов составили 101,8 кПа (медиана), 14,0-164,5 кПа (2,5-97,5-й процентили), для гиперплазированных лимфатических узлов - 15,0 кПа, 7,2-56,8 кПа соответственно. Значения модуля Юнга в метастатически измененных лимфатических узлах не коррелировали ни с уровнем инвазии первичной опухоли (меланомы) по Кларку, ни с локализацией метастазов (подмышечные, шейные, паховые лимфатические узлы). Выявлены значимые различия в значениях модуля Юнга между метастатически измененными и гиперплазированными лимфатическими узлами у пациентов с меланомой кожи (P 0,0001). Наилучшие показатели диагностической информативности в выявлении метастатического поражения лимфатических узлов при меланоме кожи достигнуты при пороговом значении модуля Юнга 22,7 кПа (чувствительность - 86%, специфичность - 77%, AUC - 0,916). Ключевые слова: ультразвуковая эластография, эластография сдвиговой волной, злокачественная меланома кожи, уровень инвазии по Кларку, толщина по Бреслоу, лимфатические узлы, модуль Юнга, скорость сдвиговой волны, ultrasound elastography, shear wave elastography, cutaneous malignant melanoma, Clark level of invasion, Breslow thickness, lymph nodes, Young’s modulus, shear wave velocity

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