On the ultrasonic attenuation and its frequency dependence in the os calcis assessed with a multielement receiver

Strelitzki, R.; Metcalfe, Stephanie; Nicholson, Patrick; Evans, JA; Paech, V.

doi:10.1016/s0301-5629(98)00154-9

Cited by 27 publications

(24 citation statements)

References 12 publications

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“…Previous investigators have identified phase cancellation at the receiving transducer as a source of artifact in attenuation measurements such as BUA and have illus- trated the use of phase insensitive and alternative forms of processing to reduce phase aberration effects. [1][2][3][4][5][6][7][23][24][25][26][27][28][29] In studies of very complicated structures represented by bone, it would be difficult to segregate effects arising from the irreversible loss of energy associated with phase cancellation at the receiving transducer from those arising from lossless redistribution of energy in the ultrasonic field. The present study was designed to permit the segregation of those effects and to illustrate the influence of the size of the receiving aperture on the interplay between these related but distinct phenomena.…”

Section: Discussionmentioning

confidence: 99%

“…[15][16][17][18][19][20][21][22] Measurements of bone are complicated by many factors associated with their inhomogeneous character and irregular shapes, making it difficult to sort out potential physical mechanisms underlying phase aberration artifacts. In vitro studies of calcaneus bone samples by Wear 6 and Strelitizki et al 3 and studies in human subjects by Wear 4 and Petley et al 2 appear to indicate that phase insensitive processing of array data yields improved estimates of the true ultrasonic attenuation. Studies by Langton et al 7,23 and by Xia et al 5 suggest that phase aberration artifacts in cancellous BUA measurements are exacerbated by the surrounding cortical bone layer.…”

Section: Introductionmentioning

confidence: 96%

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Bone sonometry: Reducing phase aberration to improve estimates of broadband ultrasonic attenuation

Bauer

Anderson

Holland

et al. 2009

The Journal of the Acoustical Society of America

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Previous studies suggest that phase cancellation at the receiving transducer can result in the overestimation of the frequency dependent ultrasonic attenuation of bone, a quantity that has been shown to correlate with bone mineral density and ultimately with osteoporotic fracture risk. Evidence supporting this interpretation is provided by phase insensitive processing of the data, which appear to reduce the apparent overestimates of attenuation. The present study was designed to clarify the components underlying phase aberration artifacts in such through-transmission measurements by conducting systematic studies of the simplest possible test objects capable of introducing phase aberration. Experimental results are presented for a Lexan phantom over the frequency range 300-700 kHz and a Plexiglas phantom over the 3 -7 MHz range. Both phantoms were flat and parallel plates featuring a step discontinuity milled into one of their initially flat sides. The through-transmitted signals were received by a 0.6 mm diameter membrane hydrophone that was raster scanned over a grid coaxial with the transmitting transducer. Signals received by the pseudoarray were processed offline to emulate phase sensitive and phase insensitive receivers with different aperture diameters. The data processed phase sensitively were focused to demonstrate the results of planar, geometrical, and correlation-based aberration correction methods. Results are presented illustrating the relative roles of interference in the ultrasonic field and phase cancellation at the receiving transducer in producing phase aberration artifacts. It was found that artifacts due to phase cancellation or interference can only be minimized with phase insensitive summation techniques by choosing an appropriately large receiving aperture. Data also suggest the potentially confounding role of time-and frequency-domain artifacts on ultrasonic measurements and illustrate the advantages of two-dimensional receiving arrays in determining the slope of attenuation ͑nBUA͒ for the clinical assessment of osteoporosis.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Bone sonometry: Reducing phase aberration to improve estimates of broadband ultrasonic attenuation

Bauer

Anderson

Holland

et al. 2009

The Journal of the Acoustical Society of America

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“…Other authors have addressed these issues in bone, and have demonstrated the artifacts inherent in phase sensitive measurements. 20,24,25 …”

Section: Introductionmentioning

confidence: 99%

Negative dispersion in bone: The role of interference in measurements of the apparent phase velocity of two temporally overlapping signals

Bauer

Marutyan

Holland

et al. 2008

The Journal of the Acoustical Society of America

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In this study the attenuation coefficient and dispersion ͑frequency dependence of phase velocity͒ are measured using a phase sensitive ͑piezoelectric͒ receiver in a phantom in which two temporally overlapping signals are detected, analogous to the fast and slow waves typically found in measurements of cancellous bone. The phantom consisted of a flat and parallel Plexiglas™ plate into which a step discontinuity was milled. The phase velocity and attenuation coefficient of the plate were measured using both broadband and narrowband data and were calculated using standard magnitude and phase spectroscopy techniques. The observed frequency dependence of the phase velocity and attenuation coefficient exhibit significant changes in their frequency dependences as the interrogating ultrasonic field is translated across the step discontinuity of the plate. Negative dispersion is observed at specific spatial locations of the plate at which the attenuation coefficient rises linearly with frequency, a behavior analogous to that of bone measurements reported in the literature. For all sites investigated, broadband and narrowband data ͑3-7 MHz͒ demonstrate excellent consistency. Evidence suggests that the interference between the two signals simultaneously reaching the phase sensitive piezoelectric receiver is responsible for this negative dispersion.

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“…However, a recent study found no significant differences in BUA values when comparing phase-sensitive and phase-insensitive approaches to calculate BUA [24]. Theoretically, phase cancellation effects should be reduced when using the DTU as it utilizes a narrower focused ultrasonic beam to produce high-resolution images.…”

Section: Discussionmentioning

confidence: 99%

Does Quantitative Ultrasound Imaging Enhance Precision and Discrimination?

Frost

Blake

Fogelman

2000

Osteoporosis International

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The aim of this study was to compare quantitative ultrasound (QUS) measurements obtained using a new calcaneal QUS imaging device with a conventional non-imaging device using fixed transducers. The study group consisted of 340 healthy women with no risk factors associated with osteoporosis (176 premenopausal and 164 postmenopausal) and 83 women with one or more vertebral fractures. All women had QUS measurements performed on the Osteometer DTU-one (imaging) and Walker-Sonix UBA575+ (non-imaging) devices and bone mineral density (BMD) measurements performed at the spine and hip. A subgroup of 81 women had additional dual-energy X-ray absorptiometry (DXA) scans at the calcaneus. Short-term standardized precision (SP = SD/young adult SD) based on duplicate measurements was significantly better on the DTU for broadband ultrasound attenuation (BUA) (SP: DTU 0.15 vs UBA 0.21,p = 0.01) and speed of sound (SOS) (SP: DTU 0.14 vs UBA 0.18, p = 0.01). However, long-term SP of the DTU was comparable to or significantly poorer than the SP of the UBA device. The BUA and SOS measurements obtained on the DTU and UBA were significantly correlated (r = 0.76 and 0.89 for BUA and SOS measurements respectively). The correlations between QUS and BMD measurements were all significant, ranging from 0.53 to 0.72. No significant improvements in the correlation with axial or peripheral BMD were observed using the imaging device. All the QUS measurement parameters showed a significant negative relationship between age and years since menopause in the postmenopausal group. Annual losses were lower for the DTU for BUA (DTU 0.22 dB/MHz per year vs UBA 0.44 dB/MHz per year) but comparable for SOS (DTU 0.29 m/s per-year vs UBA 0.22 m/s per year). However, when these figures were standardized to take into account the clinical range, the annual losses were similar on the DTU and UBA. Age-adjusted odds ratios for each SD decline were similar on the DTU for BUA (DTU 3.2 vs UBA 3.3) and SOS (DTU 3.4 vs UBA 5.1). The corresponding odds ratios for BMD at the lumbar spine, femoral neck and total hip were 2.7, 2.9 and 3.3 respectively. Age-adjusted receiver-operating characteristics analysis yielded values for the area under the curve (AUC) ranging from 0.74 to 0.83. The DTU BUA AUC of 0.83 was significantly greater than the AUC obtained for UBA BUA and BMD measurements at the lumbar spine and femoral neck. Ultrasound imaging at the calcaneus was found to improve the standardized precision of BUA and SOS measurements in the short term but not in the long term. Neither the correlation with BMD nor the discriminatory ability of QUS was improved by utilizing QUS images at the calcaneus. The inconsistencies of the imaging system used for this study demonstrate that further development is required before it will be possible to show improvements in long-term precision.

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On the ultrasonic attenuation and its frequency dependence in the os calcis assessed with a multielement receiver

Cited by 27 publications

References 12 publications

Bone sonometry: Reducing phase aberration to improve estimates of broadband ultrasonic attenuation

Bone sonometry: Reducing phase aberration to improve estimates of broadband ultrasonic attenuation

Negative dispersion in bone: The role of interference in measurements of the apparent phase velocity of two temporally overlapping signals

Does Quantitative Ultrasound Imaging Enhance Precision and Discrimination?

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