Introduction to the Physics of Ultrasound

Laugier, Pascal; Haïat, Guillaume

doi:10.1007/978-94-007-0017-8_2

Cited by 113 publications

(166 citation statements)

References 52 publications

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“…To obtain these elastic properties, quantitative ultrasound (QUS) methods in the MHz range have been used in vivo. 5 Moreover, previous studies have shown that QUS is useful for the assessment of osteoporosis using the speed of sound and broadband ultrasound attenuation. However, these parameters are affected by structure, heterogeneity, and material properties in the macroscopic area through which ultrasound waves pass.…”

Section: Introductionmentioning

confidence: 99%

Local ultrasonic wave velocities in trabeculae measured by micro-Brillouin scattering

Ryo¹,

Fukui²,

Matsukawa³

2014

The Journal of the Acoustical Society of America

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Section: Introductionmentioning

confidence: 99%

Local ultrasonic wave velocities in trabeculae measured by micro-Brillouin scattering

Ryo¹,

Fukui²,

Matsukawa³

2014

The Journal of the Acoustical Society of America

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“…For the calculations, V c ¼ 4000 m/s and V w ¼ 1500 m/s were used. (27) The TOF difference between the reference signal in water (TOF w , Fig. 2A) and the direct wave (TOF d , Fig.…”

Section: Discussionmentioning

confidence: 99%

“…(26) Hence, variations of the time-of-flight (TOF) of this wave should reflect only the variations of geometric (size, cortical thickness), material (mass density, elasticity), and structural (porosity) properties of the cortical compartment. (24,27,28) The measurement of this guided wave is all the more interesting in that the strength of the FN has been associated to bone matrix mineral content, (29,30) cortical porosity, (31) and cortical thickness, (32,33) all of these properties contributing to the propagation characteristics of the guided circumferential waves. The issue of specifically measuring ultrasonically the cortical part of the proximal femur, however, has so far not been addressed.…”

Section: Introductionmentioning

confidence: 99%

Quantitative ultrasound of cortical bone in the femoral neck predicts femur strength: Results of a pilot study

Grimal

Grondin

Guérard

et al. 2012

Journal of Bone and Mineral Research

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A significant risk of femoral neck (FN) fracture exists for men and women with an areal bone mineral density (aBMD) higher than the osteoporotic range, as measured with dual-energy X-ray absorptiometry (DXA). Separately measuring the cortical and trabecular FN compartments and combining the results would likely be a critical aspect of enhancing the diagnostic capabilities of a new technique. Because the cortical shell determines a large part of FN strength a novel quantitative ultrasound (QUS) technique that probes the FN cortical compartment was implemented. The sensitivity of the method to variations of FN cortical properties and FN strength was tested. Nine femurs (women, mean age 83 years) were subjected to QUS to measure the through transmission time-of-flight (TOF) at the FN and mechanical tests to assess strength. Quantitative computed tomography (QCT) scans were performed to enable analysis of the dependence of TOF on bone parameters. DXA was also performed for reference. An ultrasound wave propagating circumferentially in the cortical shell was measured in all specimens. Its TOF was not influenced by the properties of the trabecular compartment. Because the method involves mechanical guided waves, the QUS variable is related to the geometric and material properties of the cortical shell (cortical thickness, tissue elasticity, and porosity). This work opens the way to a multimodal QUS assessment of the proximal femur, combining our approach targeting the cortical shell with the existing modality sensitive to the trabecular compartment. In vivo feasibility of our approach has to be confirmed with experimental data in patients. ß

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“…Bones in the HIFU wave propagation passage exhibit different characteristics from those of tissue, and thus undesirable diffraction and absorption occur [11]. In the case of transcostal HIFU, the rib cage not only accumulates heat, resulting in patient discomfort, but also acts as an aberrator to the focusing beam [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

A novel sound-blocking structure based on the muffler principle for rib-sparing transcostal high-intensity focused ultrasound treatment

Chao

Hsu

et al. 2015

International Journal of Hyperthermia

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(2015) A novel sound-blocking structure based on the muffler principle for rib-sparing transcostal high-intensity focused ultrasound treatment, International Journal of Hyperthermia, 31:5, 507-527, DOI: 10.3109/02656736.2015 AbstractThe main challenge in transcostal high-intensity focused ultrasound therapy is minimising heat deposition in the ribs while ensuring that a sufficient dose is delivered to the target region. Current approaches rely on expensive multichannel phased-array systems to turn the individual transducer on and off according to either geometrical arrangements or complicated wave calculations. To protect the ribs from heating, the ultrasound energy must not only not reach the ribs, but must also not accumulate in front of the ribs. The research in this paper proposes a different approach, of attaching a sound-blocking structure in front of the rib cage with similar effects to those of an engine exhaust muffler. The sound-blocking structure is based on the muffler principle to prevent ultrasound energy from reaching the ribs and reduce the amount of energy reflected back to the applicator. Finite element simulations with a 0.5-MHz transducer of the overall sound fields and temperature distribution showed that the ultrasound pressure and energy level would decrease behind the novel sound-blocking structures, thereby resulting in a lower temperature at the ribs than at the tumour. Without the protecting structure, the rib temperature reached 104.19 C whereas with the structure it reached only 37.86 C. An experimental set-up using porcine ribs with a phantom was also developed to validate the concept, which showed that the rib temperature reached 73 C without protection within 1 min of ablation time whereas it reached 36.5 C with the device. The tumour region in the tests reached 51C and 49 C with and without protection, respectively.

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Introduction to the Physics of Ultrasound

Cited by 113 publications

References 52 publications

Local ultrasonic wave velocities in trabeculae measured by micro-Brillouin scattering

Local ultrasonic wave velocities in trabeculae measured by micro-Brillouin scattering

Quantitative ultrasound of cortical bone in the femoral neck predicts femur strength: Results of a pilot study

A novel sound-blocking structure based on the muffler principle for rib-sparing transcostal high-intensity focused ultrasound treatment

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