Longitudinal and Shear Mode Ultrasound Propagation in Human Skull Bone

Author(s):  
P. J. White
2006 ◽  
Vol 32 (7) ◽  
pp. 1085-1096 ◽  
Author(s):  
P.J. White ◽  
G.T. Clement ◽  
K. Hynynen

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jik Hang Clifford Lee ◽  
Benjamin Ondruschka ◽  
Lisa Falland-Cheung ◽  
Mario Scholze ◽  
Niels Hammer ◽  
...  

With increasingly detailed imaging and mechanical analysis, modalities need arises to update methodology and assessment criteria for skull bone analysis to understand how bone microarchitecture and the presence of attached tissues may affect the response to mechanical load. The main aim was to analyze the effect of macroscopic and microstructural features, as well as periosteal attachment, on the mechanical properties of human skull bone. Fifty-six skull specimens from ethanol-phenoxyethanol-embalmed cadavers were prepared from two human cadavers. Assuming symmetry of the skull, all samples from one-half each were stripped of periosteum and dura mater, while the soft tissues were kept intact on the remaining samples on the contralateral side. The specimens were analyzed using microcomputed tomography to assess trabecular connectivity density, total surface area, and volume ratio. The specimens were loaded under three-point bend tests until fracture with optical co-registration. The bone fragments were then lyophilized to measure their water content. With increasingly detailed imaging and mechanical analysis modalities, there is a need to update methodology and assessment criteria for skull bone analysis to understand how the bone microarchitecture and the presence of attached tissues may affect the response to mechanical load. The mechanical properties were negatively correlated to bone thickness and water content. Conversely, most microarchitectural features did not influence either mechanical parameter. The correlation between mechanical response data and morphologic properties remains similar between the results of embalmed tissues presented here and fresh osseous tissue from literature data. The findings presented here add to the existing methodology to assess human skull for research purposes. The interaction between most microarchitectural features in ethanol-phenoxyethanol-embalmed embalmed skull samples and bending stress appear to be minute.


2007 ◽  
Vol 12 (2) ◽  
pp. 101-108 ◽  
Author(s):  
R Delille ◽  
D Lesueur ◽  
P Potier ◽  
P Drazetic ◽  
E Markiewicz

2017 ◽  
Vol 62 (17) ◽  
pp. 6938-6962 ◽  
Author(s):  
Samuel Pichardo ◽  
Carlos Moreno-Hernández ◽  
Robert Andrew Drainville ◽  
Vivian Sin ◽  
Laura Curiel ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3433 ◽  
Author(s):  
Fabián Acquaticci ◽  
Sergio E. Lew ◽  
Sergio N. Gwirc

The use of axicon lenses is useful in many high-resolution-focused ultrasound applications, such as mapping, detection, and have recently been extended to ultrasonic brain therapies. However, in order to achieve high spatial resolution with an axicon lens, it is necessary to adjust the separation, called stand-off (δ), between a conventional transducer and the lens attached to it. Comprehensive ultrasound simulations, using the open-source k-Wave toolbox, were performed for an axicon lens attached to a piezo-disc type transducer with a radius of 14 mm, and a frequency of about 0.5 MHz, that is within the range of optimal frequencies for transcranial transmission. The materials properties were measured, and the lens geometry was modelled. Hydrophone measurements were performed through a human skull phantom. We obtained an initial easygoing design model for the lens angle and optimal stand-off using relatively simple formulas. The skull is not an obstacle for focusing of ultrasound with optimized axicon lenses that achieve an identical resolution to spherical transducers, but with the advantage that the focusing distance is shortened. An adequate stand-off improves the lateral resolution of the acoustic beam by approximately 50%. The approach proposed provides an effective way of designing polydimethylsiloxane (PDMS)-based axicon lenses equipped transducers.


1997 ◽  
Author(s):  
Stefan Kruszewski ◽  
Magdalena Wietlicka-Piszcz ◽  
Bronislaw Grzegorzewski

2018 ◽  
Vol 144 (3) ◽  
pp. 1748-1748
Author(s):  
Frederic Padilla ◽  
Raphaël Loyet ◽  
David Moore ◽  
Achour Ouaked ◽  
John Snell ◽  
...  

1952 ◽  
Vol 24 (4) ◽  
pp. 449-449
Author(s):  
T. F. Hueter ◽  
H. T. Ballantine ◽  
D. Kyrazis

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