Acoustic impedance measurement of tissue mimicking materials by using scanning acoustic microscopy

Ultrasonics ◽  
2021 ◽  
Vol 110 ◽  
pp. 106274 ◽  
Author(s):  
Burak Altun ◽  
Irem Demirkan ◽  
Esin Ozturk Isik ◽  
Ozgur Kocaturk ◽  
Mehmet Burcin Unlu ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Impedance Measurement ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy

scholarly journals Use of Ultrasound Microscopy for Ex Vivo Analysis of Acoustic Impedance in Mouse Liver with Steatohepatitis

Acoustics ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 3-10
Author(s):  
Hideki Kumagai ◽  
Kazuto Kobayashi ◽  
Sachiko Yoshida ◽  
Koji Yokoyama ◽  
Norio Hirota ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Ex Vivo ◽  
Acoustic Microscopy ◽  
Control Group ◽  
Scanning Acoustic Microscopy ◽  
Central Frequency ◽  
Deficient Diet ◽  
Acoustic Images ◽  
Ultrasound Microscopy

Scanning acoustic microscopy reveals information on histology and acoustic impedance through tissues. The objective of the present study was to investigate whether acoustic impedance values in the liver over time reflect the progression of steatohepatitis through different grades and stages, and whether this approach can visualize histologic features of the disease. Mice were divided into two groups: a control group and a steatohepatitis group prepared by keeping the mice on a methionine and choline-deficient diet for 56 weeks. The hepatic lobe was excised for measurement of impedance and observation of microscopic structure using a commercially available scanning acoustic microscopy system with a central frequency of 320 MHz. Scanning acoustic microscopy revealed that acoustic impedance through liver tissue with steatohepatitis temporarily decreased with the degree of fat deposition and then increased in parallel with the progression of inflammation and fibrosis. However, the acoustic images obtained did not allow discrimination of detailed microstructures from those seen using light microscopy. In conclusion, estimation of acoustic impedance appears to have potential clinical applications, such as for monitoring or follow-up studies.

The Application of Scanning Acoustic Microscopy in a Bone Remodeling Study

1995 ◽  
Vol 117 (3) ◽  
pp. 286-292 ◽  
Author(s):  
Sheu-Jane Shieh ◽  
M. C. Zimmerman ◽  
N. A. Langrana
Keyword(s):  
Bone Formation ◽  
Bone Remodeling ◽  
Acoustic Impedance ◽  
Basic Structure ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
New Bone Formation ◽  
Primary Mechanism ◽  
Low Modulus ◽  
Surface Remodeling

Scanning acoustic microscopy (SAM) was used in the evaluation of bone remodeling around a cylindrical unicortical defect. SAM is a technique for the nondestructive evaluation of materials, and has only recently been employed as an orthopaedic research tool. The utility of SAM was demonstrated by using it to measure an elastic property known as acoustic impedance. Specifically, the acoustic impedance of bone formed by remodeling around a cylindrical defect was measured. The defects were filled with either a low modulus “void” or rigid inclusion to create various states of stress in the bone in the vicinity of the defect. After six months of implantation of the inclusions in the sheep metatarsal, new bone formation on periosteal and endosteal surfaces about the defect region was observed. These regions of new bone were less stiff and had 18.0 ± 6.5% lower acoustic impedance than the pre-existing bone in the intracortical region of the metatarsal. There was no difference in the degree of new bone formation about void and rigid inclusions. Both underwent significant adaptational changes in response to the elevated stress about the defect. These changes affected the basic structure of the bone cross-section at the level of the defect and effectively reduced the stress levels about the defect. By using SAM to measure acoustic impedance, it was seen that little internal remodeling occurred in the intracortical region. Hence, the primary mechanism of strain-induced bone remodeling observed in this experimental model was surface remodeling.

Differences in acoustic impedance of fresh and embedded human trabecular bone samples—Scanning acoustic microscopy and numerical evaluation

2016 ◽  
Vol 140 (3) ◽  
pp. 1931-1936 ◽  
Author(s):  
Xiaowei Ojanen ◽  
Juha Töyräs ◽  
Satu I. Inkinen ◽  
Markus K. H. Malo ◽  
Hanna Isaksson ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Acoustic Impedance ◽  
Numerical Evaluation ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Human Trabecular Bone

Speed of sound, attenuation, and acoustic impedance of hepatic lobule in diseased rat liver observed by scanning acoustic microscopy with 250 MHz

2016 ◽  
Vol 140 (4) ◽  
pp. 3138-3138
Author(s):  
Kenji Yoshida ◽  
Zhihao Deng ◽  
Kazuyo Ito ◽  
Jonathan Mamou ◽  
Hitoshi Maruyama ◽  
...  
Keyword(s):  
Rat Liver ◽  
Speed Of Sound ◽  
Acoustic Impedance ◽  
Sound Attenuation ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Hepatic Lobule

Properties of Films Characterized by Scanning Acoustic Microscope

2014 ◽  
Vol 1061-1062 ◽  
pp. 961-965
Author(s):  
Hong Juan Yan ◽  
Chun Guang Xu ◽  
Ding Guo Xiao ◽  
Qi Lin
Keyword(s):  
Elastic Modulus ◽  
Sound Velocity ◽  
Ultrasonic Wave ◽  
Acoustic Impedance ◽  
Extreme Values ◽  
Amplitude Spectrum ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Scanning Acoustic Microscope

The scanning acoustic microscope is used to detect the properties of films. The ultrasonic wave propagates in the films with thickness h, acoustic impedance Z2 between medium with acoustic impedance Z1. The echoes from upper and lower interfaces overlap and interfere. The echoes are transformed by FFT. The interference phenomena are observed in amplitude spectrum of echoes. The spectrum has periodic extreme values at fn, fn=nc/2h. When thickness h is known, sound velocity c2 of film can be calculated. According to the principle, the properties of films such as thickness, acoustic impendence and elastic modulus are evaluated by scanning acoustic microscopy. The experimental results are good accorded with the actual properties of specimens.

Assessment of bone structure and acoustic impedance in C3H and BL6 mice using high resolution scanning acoustic microscopy

Ultrasonics ◽  
2006 ◽  
Vol 44 ◽  
pp. e1307-e1311 ◽  
Author(s):  
Tobias Hofman ◽  
Kay Raum ◽  
Ingrid Leguerney ◽  
Amena Saı¨ed ◽  
Françoise Peyrin ◽  
...  
Keyword(s):  
High Resolution ◽  
Acoustic Impedance ◽  
Bone Structure ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy

scholarly journals Examination of Cerebral Aneurysm by Scanning Acoustic Microscopy

2020 ◽  
Author(s):  
Bukem Tanoren
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Aneurysm ◽  
Acoustic Impedance ◽  
Imaging Techniques ◽  
Cerebral Aneurysms ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Female Patients ◽  
Resolution Imaging ◽  
Male Patients

Abstract Background: Asymptomatic intracranial aneurysms rupture without any warning, therefore, use of high-resolution imaging techniques for the rupture risk assessment is essential. Methods: This study’s goal is to assess the feasibility of scanning acoustic microscopy (SAM) in the characterization of cerebral aneurysm. The aneurysm’s dome samples were obtained from 12 different patients with and without subarachnoid hemorrhage. Results: The acoustic impedance values are found statistically higher in samples from female patients than in samples from male patients. On the other hand, sample from a male patient without subarachnoid hemorrhage has higher acoustic impedance value when compared with samples from male patients with subarachnoid hemorrhage, however, this discrepancy is not observed in female patients. Conclusion: In summary, the success of SAM in monitoring the altering acoustic impedance values in male and female patients with and without subarachnoid hemorrhage indicates the potential of SAM for the diagnosis of instability of cerebral aneurysms.

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