Quantifying differences in the material properties of the fiber regions of the pectoralis major using ultrasound shear wave elastography

Although spinal surgeries with minimal incisions and a minimal amount of X-ray exposure (MIMA) mostly occur in a prone posture on a Wilson table, the prone posture’s effects on spinal muscles have not been investigated. Thus, this study used ultrasound shear-wave elastography (SWE) to compare the material properties of the erector spinae and multifidus muscles when subjects lay on the Wilson table used for spinal surgery and the flat table as a control condition. Thirteen male subjects participated in the study. Using ultrasound SWE, the shear elastic moduli (SEM) of the erector spinae and multifidus muscles were investigated. Significant increases were found in the SEM of erector spinae muscle 1, erector spinae muscle 2, and multifidus muscles on the Wilson table (W) compared to in the flat table (F; W:22.19 ± 7.15 kPa, F:10.40 ± 3.20 kPa, p < 0.001; W:12.10 ± 3.31 kPa, F: 7.17 ± 1.71 kPa, p < 0.001; W: 18.39 ± 4.80 kPa, F: 11.43 ± 2.81 kPa, p < 0.001, respectively). Our results indicate that muscle material properties measured by SWE can be changed due to table posture, which should be considered in biomechanical modeling by guiding surgical planning to develop minimal-incision surgical procedures.

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Shear Wave Elastography Applied for the Investigation of Tendon Material Properties

Academic Radiology ◽

10.1016/j.acra.2016.07.001 ◽

2016 ◽

Vol 23 (10) ◽

pp. 1201-1203 ◽

Cited By ~ 1

Author(s):

James F. Greenleaf ◽

Matthew W. Urban

Keyword(s):

Shear Wave ◽

Material Properties ◽

Shear Wave Elastography

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Identifying the mechanical and neural properties of the sternocleidomastoid muscles

Journal of Applied Physiology ◽

10.1152/japplphysiol.00892.2017 ◽

2018 ◽

Vol 124 (5) ◽

pp. 1297-1303 ◽

Cited By ~ 2

Author(s):

Bhillie D. Luciani ◽

David M. Desmet ◽

Amani A. Alkayyali ◽

Joshua M. Leonardis ◽

David B. Lipps

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Shear Wave ◽

Material Properties ◽

Muscle Activity ◽

Surface Electromyography ◽

Shear Wave Elastography ◽

Moment Arms ◽

Preferred Direction ◽

The Central Nervous System

Neck muscles are preferentially activated in specific force directions, but the constraints that the central nervous system considers when programming these preferred directions of muscle activity are unknown. The current study used ultrasound shear wave elastography (SWE) to investigate whether the material properties of the sternocleidomastoid (SCM) muscles exhibit preferred directions similar to their preferred direction of muscle activity during an isometric task. Twenty-four healthy participants matched isometric forces in 16 axial directions. All force targets were scaled to 20% of a maximum voluntary contraction. Muscle activity was recorded with surface electromyography (EMG) from six muscles (the bilateral SCMs, upper trapezius, and splenius capitis muscles), and shear wave velocities (SWVs) were recorded with SWE from both SCM muscles. We observed statistically significant differences between the preferred directions of muscle activity and SWVs for both the left SCM ( P = 0.002) and the right SCM ( P < 0.001), with the SWE data exhibiting a more lateral preferred direction. Significant differences in the spatial focus ( P < 0.001) were also observed, with the dispersion of SWV data covering a greater angular range than the EMG data during isometric tasks. The preferred directions of muscle activity and material properties for the SCM muscles were closer than previous comparisons of muscle activity and moment arms, suggesting muscle mechanics could play a more important role than anatomy in how the central nervous system spatially tunes muscle activation. NEW & NOTEWORTHY Our study used a novel combination of surface electromyography and ultrasound shear wave elastography to investigate the neuromuscular control of the neck. Our work highlights differences in how the activation and material properties of the sternocleidomastoid muscles are modulated as the central nervous system stabilizes the neck during isometric force production. These findings provide normative data for future studies to investigate pathologic changes to both the activation and material properties of the sternocleidomastoid muscles.

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Material Properties of the Medial Elbow During Passive Valgus and Self-Initiated Varus Torques

Journal of Applied Biomechanics ◽

10.1123/jab.2020-0095 ◽

2020 ◽

pp. 1-7

Author(s):

Brian J. Diefenbach ◽

Anthony S. Kulas ◽

Christopher J. Curran ◽

Patrick M. Rider

Keyword(s):

Shear Wave ◽

Material Properties ◽

Muscle Activation ◽

Ulnar Collateral Ligament ◽

Shear Wave Elastography ◽

Muscle Stiffness ◽

Neutral Position ◽

Flexor Muscle ◽

Wrist Flexor ◽

Wrist Flexors

Shear wave elastography imaging of the ulnar collateral ligament (UCL) is used to help understand changes in material properties of the ligament. Ensuring that the wrist flexors are relaxed is essential as muscle contractions can alter the alignment of the medial elbow. The purpose of this study was to determine how the structural and material properties of the medial elbow respond to various elbow torques. The medial elbows of 20 healthy adults, free from upper extremity disorders, were imaged in 3 of the following torque conditions: (1) neutral relaxed, (2) passive valgus, and (3) active varus. Structural properties (ulnohumeral gap and UCL length) using B-mode and material properties (UCL and flexor muscle stiffness) using shear wave were measured. Passive valgus torque opened the ulnohumeral gap (P < .001), and increased UCL (P < .001) and wrist flexor stiffness (P = .001), compared with the neutral condition. Under an active varus contraction, the gap returned back to the neutral position, but UCL (P < .008) and wrist flexor stiffness (P < .004) remained elevated compared with neutral, meaning low-intensity torques can influence structural and material properties of the medial elbow. Therefore, effort should be taken to minimize muscle activation during imaging in order to accurately measure medial elbow properties.

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Liver Elastography in Healthy Children Using Three Different Systems – How Many Measurements Are Necessary?

Ultraschall in der Medizin - European Journal of Ultrasound ◽

10.1055/a-1283-5906 ◽

2020 ◽

Author(s):

Anders Batman Mjelle ◽

Anesa Mulabecirovic ◽

Roald Flesland Havre ◽

Edda Jonina Olafsdottir ◽

Odd Helge Gilja ◽

...

Keyword(s):

Shear Wave ◽

Transient Elastography ◽

Intraclass Correlation ◽

Age Groups ◽

Liver Stiffness ◽

Shear Wave Elastography ◽

Healthy Children ◽

Significant Difference ◽

Pediatric Liver Disease ◽

Liver Elastography

Abstract Purpose Liver elastography is increasingly being applied in screening for and follow-up of pediatric liver disease, and has been shown to correlate well with fibrosis staging through liver biopsy. Because time is of the essence when examining children, we wanted to evaluate if a reliable result can be achieved with fewer acquisitions. Materials and Methods 243 healthy children aged 4–17 years were examined after three hours of fasting. Participants were divided into four age groups: 4–7 years; 8–11 years; 12–14 years and 15–17 years. Both two-dimensional shear wave elastography (2D-SWE; GE Logiq E9) and point shear wave elastography (pSWE; Samsung RS80A with Prestige) were performed in all participants, while transient elastography (TE, Fibroscan) was performed in a subset of 87 children aged 8–17 years. Median liver stiffness measurement (LSM) values of 3, 4, 5, 6, 7, and 8 acquisitions were compared with the median value of 10 acquisitions (reference standard). Comparison was performed for all participants together as well as within every specific age group. We investigated both the intraclass correlation coefficient (ICC) with absolute agreement and all outliers more than 10 %, 20 % or ≥ 0.5 or 1.0 kPa from the median of 10 acquisitions. Results For all three systems there was no significant difference between three and ten acquisitions, with ICCs ≥ 0.97. All systems needed 4 acquisitions to achieve no LSM deviating ≥ 1.0 kPa of a median of ten. To achieve no LSM deviating ≥ 20 % of a median of ten acquisitions, pSWE and TE needed 4 acquisitions, while 2D-SWE required 6 acquisitions. Conclusion Our results contradict recommendations of 10 acquisitions for pSWE and TE and only 3 for 2D-SWE.

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