Quantitative sonoelastography for the<i>in vivo</i>assessment of skeletal muscle viscoelasticity

Hoyt, Kenneth; Kneezel, Timothy; Castaneda, Benjamín; Parker, Kevin J.

doi:10.1088/0031-9155/53/15/004

Cited by 143 publications

(114 citation statements)

References 40 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…5 The shear moduli, on the other hand, can vary by more than a factor of 10, potentially providing greater contrast. [6][7][8] Understanding shear wave behavior is key to dynamic elastography techniques that use magnetic resonance imaging (MRI) or Doppler ultrasound (US) procedures to generate images of the shear wave field. Surface wave behavior, measured via optical or Doppler US methods, has also been studied for the same reasons.…”

Section: Introductionmentioning

confidence: 99%

Estimating material viscoelastic properties based on surface wave measurements: A comparison of techniques and modeling assumptions

Royston

Dai

Chaunsali

et al. 2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Previous studies of the first author and others have focused on low audible frequency (<1 kHz) shear and surface wave motion in and on a viscoelastic material comprised of or representative of soft biological tissue. A specific case considered has been surface (Rayleigh) wave motion caused by a circular disk located on the surface and oscillating normal to it. Different approaches to identifying the type and coefficients of a viscoelastic model of the material based on these measurements have been proposed. One approach has been to optimize coefficients in an assumed viscoelastic model type to match measurements of the frequency-dependent Rayleigh wave speed. Another approach has been to optimize coefficients in an assumed viscoelastic model type to match the complex-valued frequency response function (FRF) between the excitation location and points at known radial distances from it. In the present article, the relative merits of these approaches are explored theoretically, computationally, and experimentally. It is concluded that matching the complex-valued FRF may provide a better estimate of the viscoelastic model type and parameter values; though, as the studies herein show, there are inherent limitations to identifying viscoelastic properties based on surface wave measurements.

show abstract

Section: Introductionmentioning

confidence: 99%

Estimating material viscoelastic properties based on surface wave measurements: A comparison of techniques and modeling assumptions

Royston

Dai

Chaunsali

et al. 2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…Stiff regions indicate an abnormality. Experiments that are devised to create displacement that will yield tissue mechanical properties include: ͑1͒ tissue is compressed; stiff tissue compresses less; the displacement is measured using ultrasound or MR; the Lamé parameter, , is imaged, ͑Oberai et al., 2004;Barbone and Bamber, 2002;Konofagou et al, 2000;Thitaikumar and Ophir, 2007͒; ͑2͒ a time harmonic excitation is applied; the maximum displacement at each point in the image plane is measured using ultrasound and the displacement is imaged ͑Gao et al, 1995;Taylor et al, 2000;Wu et al, 2002͒; or the displacement, using MR, is measured at 4 to 8 equally spaced times in a period cycle, the shear wave speed or the Lamé parameter, , is imaged ͑Greenleaf et al., 1996;Kruse et al, 2000;Braun et al, 2001;Manduca et al, 2001Manduca et al, , 2002Manduca et al, , 2003Ehman et al, 2006;Sinkus et al, 2007͒; ͑3͒ a traveling wave is created using: ͑a͒ a line source created by a sequence of interior radiation force pushes ͑Ber-coff et al., 2002, 2004͒, and a primarily shear wave, with a front, travels outward from the source; the speed of the wave front is imaged ͑McLaughlin and Renzi, 2006aRenzi, , 2006bTanter et al, 2008͒; a point source is created by an interior radiation force push and the local shear wave speed is determined by measuring the time to peak at a nearby location ͑Nightingale et al, 2001a͑Nightingale et al, , 2001bFahey et al, 2005;Palmeri et al, 2006͒; or ͑b͒ two harmonic sources that oscillate at different but nearly the same frequency; the traveling wave speed is imaged ͑Castaneda et al, 2009;Hoyt et al, 2006Hoyt et al, , 2007aHoyt et al, , 2007bHoyt et al, , 2007cHoyt et al, , 2008aHoyt et al, , 2008b…”

Section: Introductionmentioning

confidence: 99%

Shear wave speed recovery in sonoelastography using crawling wave data

Lin

McLaughlin

Renzi

et al. 2010

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

The crawling wave experiment, in which two harmonic sources oscillate at different but nearby frequencies, is a development in sonoelastography that allows real-time imaging of propagating shear wave interference patterns. Previously the crawling wave speed was recovered and used as an indicator of shear stiffness; however, it is shown in this paper that the crawling wave speed image can have artifacts that do not represent a change in stiffness. In this paper, the locations and shapes of some of the artifacts are exhibited. In addition, a differential equation is established that enables imaging of the shear wave speed, which is a quantity strongly correlated with shear stiffness change. The full algorithm is as follows: ͑1͒ extract the crawling wave phase from the spectral variance data; ͑2͒ calculate the crawling wave phase wave speed; ͑3͒ solve a first-order PDE for the phase of the wave emanating from one of the sources; and ͑4͒ compute and image the shear wave speed on a grid in the image plane.

show abstract

“…For instance, a contractile muscle flap experiences episodes of stiffening during load bearing as the musculature of the limb contracts, 14 whereas a severed muscle flap degenerates and becomes less contractible, 17 more fibrotic or even flaccid.…”

Section: Introductionmentioning

confidence: 99%

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

et al. 2009

View full text Add to dashboard Cite

The residual limb of transtibial amputation (TTA) prosthetic users is threatened daily by pressure ulcers (PU) and deep tissue injury (DTI) caused mainly by sustained mechanical strains and stresses. Several risk factors dominate the extent of internal tissue loads in the residuum. In this study, we developed a set of three-dimensional finite element (FE) models that were variants of a patient-specific FE model, built from magnetic resonance imaging scans. The set of FE modes was utilized to assess the impact of the following risk factors on the strain/stress distribution in the muscle flap: (i) the tibial length, (ii) the tibial bevelment, (iii) a fibular osteophyte, (iv) the mechanical properties of the muscle, and (v) scarring in different locations and depths. A total of 12 nonlinear FE model configurations, representing variations in these factors, were built and solved. We present herein calculations of compression, tension and shear strains and stresses, von Mises stresses, and strain energy density averaged in critical locations in the muscle flap as well as volumes of concentration of elevated stresses in these areas. Our results overall show higher stresses accumulating in the bone proximity rather than in outlying soft tissues. The longer bone configurations spread the loads toward the external surfaces of the muscle flap. When shortening the truncated bones from 11.2 to 9.2 cm, the von Mises stresses at the distal edges of the bones were relieved considerably (by up to 80%), which indicates a predicted decreased risk for DTI. Decreasing the tibial bevelment mildly, from 52.3 degrees to 37.7 degrees caused propagation of internal stresses from the bone proximity toward the more superficial soft tissues of the residuum, thereby also theoretically reducing the risk for DTI. An osteophyte at the distal fibular end increased the strain and stress distributions directly under the fibula but had little effect (<1%) on stresses at other sites, e.g., under the tibia. Elevation of muscle stiffness (instantaneous shear modulus increase from 8.5 to 16.2 kPa), simulating variation between patients, and muscle flap contraction or spasm, showed the most substantial effect by an acute rise of the von Mises stresses at the bone proximity. The mean von Mises stresses at the bone proximity were approximately twofold higher in the contracted/spastic muscle when compared to the flaccid muscle. Locating a surgical scar in different sites and depths of the residuum had the least influence on the overall loading of the muscle flap (where stresses changed by <7%). Pending further validation by epidemiological PU and DTI risk factor studies, the conclusions of this study can be incorporated as guidelines for TTA surgeons, physical therapists, prosthetists, and the TTA patients themselves to minimize the onset of PU and DTI in this population. Additionally, the present analyses can be used to guide or focus epidemiological research of PU and DTI risk factors in the TTA population.

show abstract

Quantitative sonoelastography for thein vivoassessment of skeletal muscle viscoelasticity

Cited by 143 publications

References 40 publications

Estimating material viscoelastic properties based on surface wave measurements: A comparison of techniques and modeling assumptions

Estimating material viscoelastic properties based on surface wave measurements: A comparison of techniques and modeling assumptions

Shear wave speed recovery in sonoelastography using crawling wave data

Surgical and Morphological Factors that Affect Internal Mechanical Loads in Soft Tissues of the Transtibial Residuum

Contact Info

Product

Resources

About