Bias Observed in Time-of-Flight Shear Wave Speed Measurements Using Radiation Force of a Focused Ultrasound Beam

Zhao, Heng; Song, Pengfei; Urban, Matthew W.; Kinnick, Randall R.; Yin, Min-Jean; Greenleaf, James F.; Chen, Shigao

doi:10.1016/j.ultrasmedbio.2011.07.012

Cited by 96 publications

(98 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Table I summarizes speed measurements from different measurements in two phantoms. The speeds measured are higher than those of the MRE reference measurements but are in accordance with values found by Zhao, et al, in a comprehensive study of these phantoms when using 64 elements for the push [19]. The speeds from optimal SWC with two pushes were in good agreement with results from the long pushes.…”

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Shear wave construction with laterally moving radiation force excitations

Urban

Amador

Nabavizadeh

et al. 2011

2011 IEEE International Ultrasonics Symposium

Self Cite

View full text Add to dashboard Cite

Shear wave-based elasticity methods which quantify shear wave speed, c s , are becoming clinically relevant as many pathological conditions change values of c s in soft tissue. Reliable measurements require shear waves with high signal-to-noise ratio that propagate far enough to measure c s . Push tonebursts must have long duration and/or high intensity, but ultrasound exposure regulations limit deposited energy so trade-offs must be made to find new solutions for creating shear waves for clinically reliable measurements.We present a method called shear wave construction (SWC) that uses multiple, short tonebursts, transmitted at different times and lateral locations to augment a propagating shear wave. To optimally sustain a propagating shear wave tonebursts must be transmitted at the time-of-arrival (TOA) of the shear wave at different lateral locations. To do this optimally c s must be known, but typically is not. We studied SWC using either two or three short pushes of length 100 μs, which resulted in one wave front that is reinforced and in the other direction, multiple wave fronts are created. We performed simulations with the intensity field used as the force input to a Green's function analysis to analyze the shear wave displacement and also varied the time of the pulses away from the optimal TOA.We performed experiments using a linear array in three elastic phantoms where c s values were known. We designed optimal pulse sequences for the phantoms and compared SWC displacement and c s results with results from a single push with lengths of 100, 200, or 300 μs. Displacement was measured over a 2 cm lateral extent with plane wave imaging performed at 2.5 kHz. Lastly, we used SWC in an excised porcine kidney to evaluate feasibility in soft tissue.The displacement generated in the simulations agreed well with the experimental results. The percent error for c s ranged from 3.1-7.1% in the phantoms. The SWC peak displacement through time at each location with two pushes of 100 μs was larger than that generated using a 100 or 200 μs.The SWC method provided accurate measurements of c s in elastic phantoms. This method uses short tonebursts which are less taxing on the scanner power supply, allow for higher detection frame rates without interference from pushing pulses, and have higher displacement bandwidth.

show abstract

Section: Discussionsupporting

confidence: 89%

“…The two phantoms had shear wave speeds of 1.47 and 1.80 m/s as measured by MRE [19]. We programmed sequences with two and three pushes to optimally perform SWC.…”

Section: Methodsmentioning

confidence: 99%

Shear wave construction with laterally moving radiation force excitations

Urban

Amador

Nabavizadeh

et al. 2011

2011 IEEE International Ultrasonics Symposium

Self Cite

View full text Add to dashboard Cite

show abstract

“…And results are relatively consistent over the whole axial (depth) range studied. This may be a beneficial feature compared to shear wave speed measured with focused push beam, which can show relatively large variation with depth of measurement, especially in the transducer near field [8]. Results obtained with unfocused push are similar to those obtained with MRE and 1D TE in all 3 phantoms.…”

Section: Discussionsupporting

confidence: 61%

“…Each phantom had a dimension of 10 × 10 × 8 cm 3 (width, depth, height). The shear wave speed in each phantom was calibrated by Magnetic Resonance Elastography (MRE) and 1D Transient Elastography (TE) in a previous study [8]. The mean and standard deviations of shear wave speed measured at 100 Hz by MRE are 1.24 ± 0.01 m/s, 1.47 ± 0.02 m/s, and 1.80 ± 0.02 m/s for phantoms 1, 2, and 3, respectively.…”

Section: B Phantom Experimentsmentioning

confidence: 99%

Shear wave speed measurement using an unfocused ultrasound push beam

Chen

Zhao

Song

et al. 2011

2011 IEEE International Ultrasonics Symposium

Self Cite

View full text Add to dashboard Cite

Tissue viscoelasticity is related to pathology and therefore has important medical applications. Radiation force from a focused ultrasound beam has been used to produce shear wave in tissues for shear wave speed and tissue elasticity measurements. The feasibility of shear wave speed measurement using radiation force of an unfocused ultrasound beam is demonstrated in this study with a linear and a curved array transducer. Good estimation of shear wave speed was achieved in 3 calibrated phantoms with different shear modulus. Shear wave speed can be measured over a relatively long axial extent (z = 10-40 mm for the linear array, and z = 15-60 mm for the curve array) from a single acquisition with an unfocused push beam. In vivo measurements on the biceps of a healthy volunteer show consistent increase of shear modulus for the biceps under 0, 1, 2, and 3 kg loading. Advantages and limitation of unfocused push are discussed.

show abstract

“…Another factor that influenced kidney SWV in our subjects was the depth of measurement; the decrease of the measured SWV was previously related to an increase in depthin studies performed on phantoms [26,27] or liver [28,29]. A marker of disease activity, proteinuria, has been mentioned in the literature as an influencing factor for kidney SWV [27], but we found no significant correlation between proteinuria and kidney SWV in our patients.…”

Section: Discussionmentioning

confidence: 49%

Is there a correlation between kidney shear wave velocity measured with VTQ and histological parameters in patients with chronic glomerulonephritis? A pilot study

Bob¹,

Grosu²,

Sporea³

et al. 2018

Med Ultrason

View full text Add to dashboard Cite

Aim: To analyze the relationship between shear wave velocity in the kidney measured by point shear wave elastography using Virtual Touch Quantification (VTQ) (Siemens Acuson S2000) and histological parameters obtained from renal biopsies, in patients with chronic glomerulonephritis (CGN).Material and methods: The study group included 20 patients (mean age 47.95±13.59 years) with different types of CGN, that had underwent renal biopsy and 57 normal controls (mean age 38.07±17.32 years). In all patients, five valid stiffness measurements were obtained in each kidney, with the patient in lateral decubitus. Regarding the histological results, we assessed the presence or absence of glomerulosclerosis, interstitial fibrosis, and arteriolo-hyalinosis.Results: In patients with CGN we obtained the following mean values of VTQ values: right kidney: 2.12±0.81 m/s, left kidney 1.65±0.54 m/s, while in the normal controls significantly higher VTQ values were obtained: right kidney 2.69±0.72 m/s (p=0.004), left kidney 2.48±0.73 m/s (p<0.0001). In patients with CGN no statistically significant correlations between VTQ values and eGFR (r=0.37, p=0.12) or proteinuria (r=0.2, p=0.37) were found. We found significantly lower VTQ values in patients with interstitial fibrosis (1.46 vs. 1.99 m/s, p<0.05) and also in patients with arteriolo-hyalinosis (1.55 vs. 2.47 m/s, p<0.05).Conclusion: Our pilot study shows that shear wave velocity values in patients with CGN are significantly lower compared to normal controls, and there is a tendency to decrease with the decrease of eGFR, with the presence of interstitial fibrosis and of arteriolo-hyalinosis.

show abstract

Bias Observed in Time-of-Flight Shear Wave Speed Measurements Using Radiation Force of a Focused Ultrasound Beam

Cited by 96 publications

References 21 publications

Shear wave construction with laterally moving radiation force excitations

Shear wave construction with laterally moving radiation force excitations

Shear wave speed measurement using an unfocused ultrasound push beam

Is there a correlation between kidney shear wave velocity measured with VTQ and histological parameters in patients with chronic glomerulonephritis? A pilot study

Contact Info

Product

Resources

About