scholarly journals Finite Element Modeling for a Morphometric and Mechanical Characterization of Trabecular Bone from High Resolution Magnetic Resonance Imaging

10.5772/9977 ◽  
2010 ◽  
Author(s):  
Angel Alberich-Bayarri ◽  
Luis Marti-Bonmati ◽  
M. Angeles ◽  
Juan Jos ◽  
David Moratal
Keyword(s):  
Magnetic Resonance Imaging ◽  
Finite Element ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Finite Element Modeling ◽  
Trabecular Bone ◽  
Mechanical Characterization ◽  
Resonance Imaging ◽  
Element Modeling

scholarly journals Glassy carbon microelectrodes minimize induced voltages, mechanical vibrations, and artifacts in magnetic resonance imaging

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Surabhi Nimbalkar ◽  
Erwin Fuhrer ◽  
Pedro Silva ◽  
Tri Nguyen ◽  
Martin Sereno ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Thin Film ◽  
Finite Element ◽  
Magnetic Resonance ◽  
Finite Element Modeling ◽  
Glassy Carbon ◽  
Resonance Imaging ◽  
Neural Probes ◽  
Element Modeling ◽  
Polymeric Substrates

AbstractThe recent introduction of glassy carbon (GC) microstructures supported on flexible polymeric substrates has motivated the adoption of GC in a variety of implantable and wearable devices. Neural probes such as electrocorticography and penetrating shanks with GC microelectrode arrays used for neural signal recording and electrical stimulation are among the first beneficiaries of this technology. With the expected proliferation of these neural probes and potential clinical adoption, the magnetic resonance imaging (MRI) compatibility of GC microstructures needs to be established to help validate this potential in clinical settings. Here, we present GC microelectrodes and microstructures—fabricated through the carbon micro-electro-mechanical systems process and supported on flexible polymeric substrates—and carry out experimental measurements of induced vibrations, eddy currents, and artifacts. Through induced vibration, induced voltage, and MRI experiments and finite element modeling, we compared the performances of these GC microelectrodes against those of conventional thin-film platinum (Pt) microelectrodes and established that GC microelectrodes demonstrate superior magnetic resonance compatibility over standard metal thin-film microelectrodes. Specifically, we demonstrated that GC microelectrodes experienced no considerable vibration deflection amplitudes and minimal induced currents, while Pt microelectrodes had significantly larger currents. We also showed that because of their low magnetic susceptibility and lower conductivity, the GC microelectrodes caused almost no susceptibility shift artifacts and no eddy-current-induced artifacts compared to Pt microelectrodes. Taken together, the experimental, theoretical, and finite element modeling establish that GC microelectrodes exhibit significant MRI compatibility, hence demonstrating clear clinical advantages over current conventional thin-film materials, further opening avenues for wider adoption of GC microelectrodes in chronic clinical applications.

scholarly journals High Resolution Magnetic Resonance Imaging for Characterization of the Neuroligin-3 Knock-in Mouse Model Associated with Autism Spectrum Disorder

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e109872 ◽  
Author(s):  
Manoj Kumar ◽  
Jeffery T. Duda ◽  
Wei-Ting Hwang ◽  
Charles Kenworthy ◽  
Ranjit Ittyerah ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Autism Spectrum Disorder ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Mouse Model ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Resonance Imaging

High‐resolution magnetic resonance imaging of trabecular bone in the wrist at 3 tesla: initial results

2005 ◽  
Vol 46 (3) ◽  
pp. 306-309 ◽  
Author(s):  
B. Ludescher ◽  
P. Martirosian ◽  
S. Lenk ◽  
J. Machann ◽  
F. Dammann ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Trabecular Bone ◽  
Spatial Resolution ◽  
Bone Structure ◽  
3 Tesla ◽  
Spongy Bone ◽  
Resonance Imaging ◽  
High Resolution Mri

Purpose: To evaluate the feasibility of high‐resolution magnetic resonance imaging (MRI) of trabecular bone of the wrist at 3 Tesla (3T) in vivo and to assess the potential benefit of the increased resolution for clinical assessment of structural changes in spongy bone. Material and Methods: High‐resolution MRI of the wrist was performed with a whole‐body 3T MR scanner using a dedicated circularly polarized transmit–receive wrist‐coil. Two 3D‐FISP sequences with a spatial resolution of 300×300×300 µm3 in a measuring time of TA = 7:51 min, and 200×200×200 µm3 in TA = 9:33 min were applied. Seven young healthy volunteers and three elderly subjects with suspected osteoporosis were examined. The signal‐to‐noise ratio (SNR) in the optimized setup at 3T was compared to measurements at 1.5T. Results: The images at 3T allow microscopic analysis of the bone structure at an isotropic spatial resolution of 200 µm in examination times of <10 min. Differences in the structure of the spongy bone between normal and markedly osteoporotic subjects are well depicted. The SNR at 3T was found up to 16 times higher than at 1.5T applying unchanged imaging parameters. Conclusion: The proposed high‐resolution MRI technique offers high potential in the diagnosis and follow‐up of diseases with impaired bone structure of hand and/or wrist in clinical applications.

scholarly journals Synthesis of NanoQ, a Copper-Based Contrast Agent for High-Resolution Magnetic Resonance Imaging Characterization of Human Thrombus

2011 ◽  
Vol 133 (24) ◽  
pp. 9168-9171 ◽  
Author(s):  
Dipanjan Pan ◽  
Shelton D. Caruthers ◽  
Angana Senpan ◽  
Ceren Yalaz ◽  
Allen J. Stacy ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Contrast Agent ◽  
Resonance Imaging ◽  
Imaging Characterization
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