Estimation of ultrasonic attenuation in a bone using coded excitation

A novel switched excitation method for linear frequency modulated excitation of ultrasonic transducers in pulse compression systems is presented that is simple to realise, yet provides reduced signal sidelobes at the output of the matched filter shows improvements in signal to sidelobe noise power in the order of 7 to 8 dB.The reported quinary switched method for linear frequency modulated excitation provides improved performance compared to pesudo chirp excitation without the need for high performance excitation amplifiers.

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“…Bridging the gap between NDT and medical systems have been papers monitoring bone thickness and density [11,12].…”

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confidence: 99%

Quinary excitation method for pulse compression ultrasound measurements

Cowell

Freear

2008

Ultrasonics

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“…1. The chirp voltage is: (2) where α = Δf/T p is the frequency-ramp constant in MHz/µs; w[n] is a Tukey window function [14]:…”

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confidence: 99%

“…Under low echo-signal-to-noise-ratio (eSNR) conditions, temporally coded excitation pulses provide distinct advantages. For example, they have been shown to improve eSNR in vascular imaging with intravascular ultrasound (IVUS) arrays [1], in bone attenuation estimates [2], in bubble-preserving, nonlinear contrast imaging [3], in three-dimensional (3-D) imaging using parallel acquisition [4], and in very high frame rate 2-D acquisitions when combined with spatial encoding [5]. Coded excitation provides greater penetration by increasing the average power delivered to tissues without increasing peak power [6]- [8].…”

Section: Introductionmentioning

confidence: 99%

Coded pulse excitation for ultrasonic strain imaging

Liu¹,

Insana

2005

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Decorrelation strain noise can be significantly reduced in low echo-signal-to-noise (eSNR) conditions using coded excitation. Large time-bandwidth-product (>30) pulses are transmitted into tissue mimicking phantoms with 2.5-mm diameter inclusions that mimic the elastic properties of breast lesions. We observed a 5-10 dB improvement in eSNR that led to a doubling of the depth of focus for strain images with no reduction of spatial resolution. In high eSNR conditions, coded excitation permits the use of higher carrier frequencies and shorter correlation windows to improve the attainable spatial resolution for strain relative to that obtained with conventional short pulses. This paper summarizes comparative studies of strain imaging in noise-limited conditions obtained by short pulses and four common aperiodic codes (chirp, Barker, suboptimal, and Golay) as a function of attenuation, eSNR and applied strain. Imaging performance is quantified using SNR for displacement (SNR d ), local modulation transfer function (LMTF), and contrast-to-noise ratio for strain (CNR ϵ ). We found that chirp and Golay codes are the most robust for imaging soft tissue deformation using matched filter decoding. Their superior performance is obtained by balancing the need for low-range lobes, large eSNR improvement, and short-code duration.

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“…28,8 Diagnostic ultrasound for osteoporosis detection and evaluation is well documented. 7,9,13,[15][16][17][19][20][21][22][23][29][30][31][32]34 Unlike its X-ray based counterpart tools, ultrasoundbased techniques offer clear advantages due to their non-ionizing nature, low cost, portability, and ease of use. Ultrasonic characterization of backscatter from human cancellous bone with Renyi entropy was shown to have a correlation with X-ray BMD in the study done by Wallace et al 29 This work assessed material properties of cancellous bone as compared with pQCT.…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic Evaluation of Bone Quality in Cadaver Ilia

Ghorayeb

Rooney

2013

Ann Biomed Eng

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Several imaging modalities have traditionally been utilized to assess bone health. However, none of these standards is capable of providing a clear rendition or display of the damaged bone layers caused, for instance, by osteoporosis. This study examines the use of ultrasound for non-invasive monitoring of bone quality in bone samples with various degrees of porosity. A user-defined region of interest (ROI) in the iliac portion of extracted human cadaver coxal bones is monitored and quantified. Raster C-scan images of the ROI were acquired and compared to basic physical measurements, and to bone scans using dual energy X-ray absorptiometry (DXA). A quantitative measure of the superficial sub-surface composite matrix (ScM) content was analyzed using linear regression with all physical and DXA measures. The trend in the degree of percent bone loss (PBL) measured by ultrasound (US) was found to be closely paralleled with that measured by DXA (R(2) = 0.82, p < .0005). Also, the trend in which PBL (US) correlated with bone mineral density (BMD) (R(2) = 0.62, p < .01) was found to exhibit a similar behavior when the latter was compared to dry mass density (DmD) of the bone samples (R(2) = 0.63, p < .01). However, when PBL (DXA) was compared to DmD, it did reveal a better linearity (R(2) = 0.69, p < .005) than the one obtained when PBL (US) was compared with the same DmD (R(2) = 0.45, p < .05). A similar outcome was observed when PBL (US) was compared with percent porosity (R(2) = 0.51, p < .05), as opposed to the better linearity exhibited between PBL (DXA) and porosity (R(2) = 0.86, p < .0005). Despite these slight variations, further analyses on the statistical significance between these correlations suggest that ultrasound can be an effective imaging technique in assessing the degree of bone damage, and can be used to assess the structural integrity of bones.

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Estimation of ultrasonic attenuation in a bone using coded excitation

Cited by 29 publications

References 5 publications

Quinary excitation method for pulse compression ultrasound measurements

Quinary excitation method for pulse compression ultrasound measurements

Coded pulse excitation for ultrasonic strain imaging

Ultrasonic Evaluation of Bone Quality in Cadaver Ilia

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