scholarly journals Design of a Coplanar Interlayer Gapped Microstrips Arrangement for Multi-Nuclei (1H, 19F, 31P, and 23Na) Applications in 7T MRI

2021 ◽  
Vol 11 (3) ◽  
pp. 957
Author(s):  
Daniel Hernandez
Keyword(s):  
Magnetic Resonance ◽  
Dielectric Materials ◽  
Rf Coil ◽  
High Quality ◽  
Anatomical Images ◽  
B1 Field ◽  
Materials Used ◽  
Current Lines ◽  
A Current ◽  
Metabolic Information

Seven Tesla Magnetic Resonance (MR) systems can obtain high quality anatomical images using protons (1H) and can be used for multinuclear imaging and MR spectroscopy. These imaging modes can also obtain images and metabolic information using other nuclei, such as 19F, 31P, and 23Na. Here, we present an RF coil unit using a microstrip capable of resonating at four frequencies: 300 (1H), 280 (19F), 121 (31P), and 78 (23Na) MHz. The RF unit consists of a single feeding port and four lines that resonate and run a current at their respective frequency. We used the gapped microstrip concept to isolate each conducting line and interleaved the dielectric materials used for each line, thereby reducing the coupling between them. We also analyzed this design using electromagnetic (EM) simulations, and found that the quad tuned arrangement produced low coupling between adjacent current lines and achieved a uniform |B1| field in the z-y plane.

Magnetic resonance imaging in study of lungs

2019 ◽  
pp. 10-23
Author(s):  
T. A. Akhadov ◽  
S. Yu. Guryakov ◽  
M. V. Ublinsky
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Medical Society ◽  
Resonance Imaging ◽  
Iodinated Contrast ◽  
Long Time ◽  
Women And Children ◽  
Magnetic Resonance Imaging Mri ◽  
A Current ◽  
Lung Mri

For a long time, there was a need to apply magnetic resonance imaging (MRI) technique for lung visualization in clinical practice. The development of this method is stimulated by necessity of the emergence of an alternative to computed tomography, especially when radiation and injection of iodine-containing contrast agents are contraindicated or undesirable, for example, in pregnant women and children, people with intolerance to iodinated contrast. One of the reasons why lung MRI is still rarely used is lack of elaborated standardized protocols that would be adapted to clinical needs of medical society. This publication is a current literature review on the use of MRI in lung studies.

Surface flashover of dielectric materials used in pulsed power research

2007 ◽  
Author(s):  
M.P. Wilson ◽  
R.A. Fouracre ◽  
M.J. Given ◽  
S.J. MacGregor ◽  
I.V. Timoshkin ◽  
...  
Keyword(s):  
Dielectric Materials ◽  
Pulsed Power ◽  
Surface Flashover ◽  
Materials Used

scholarly journals Hyperpolarized 13C-glucose magnetic resonance highlights reduced aerobic glycolysis in vivo in infiltrative glioblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mor Mishkovsky ◽  
Olga Gusyatiner ◽  
Bernard Lanz ◽  
Cristina Cudalbu ◽  
Irene Vassallo ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Tumor Recurrence ◽  
Aerobic Glycolysis ◽  
Imaging Techniques ◽  
Tumor Type ◽  
Hyperpolarized 13C ◽  
Metabolic Heterogeneity ◽  
Metabolic Information ◽  
Opposite Response

AbstractGlioblastoma (GBM) is the most aggressive brain tumor type in adults. GBM is heterogeneous, with a compact core lesion surrounded by an invasive tumor front. This front is highly relevant for tumor recurrence but is generally non-detectable using standard imaging techniques. Recent studies demonstrated distinct metabolic profiles of the invasive phenotype in GBM. Magnetic resonance (MR) of hyperpolarized 13C-labeled probes is a rapidly advancing field that provides real-time metabolic information. Here, we applied hyperpolarized 13C-glucose MR to mouse GBM models. Compared to controls, the amount of lactate produced from hyperpolarized glucose was higher in the compact GBM model, consistent with the accepted “Warburg effect”. However, the opposite response was observed in models reflecting the invasive zone, with less lactate produced than in controls, implying a reduction in aerobic glycolysis. These striking differences could be used to map the metabolic heterogeneity in GBM and to visualize the infiltrative front of GBM.

scholarly journals Custom, spray coated receive coils for magnetic resonance imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. M. Zamarayeva ◽  
K. Gopalan ◽  
J. R. Corea ◽  
M. Z. Liu ◽  
K. Pang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Silver Nanoparticle ◽  
Material Selection ◽  
Spray Deposition ◽  
Dielectric Materials ◽  
Patient Specific ◽  
High Signal ◽  
Resonance Imaging ◽  
3D Printed

AbstractWe have developed a process for fabricating patient specific Magnetic Resonance Imaging (MRI) Radio-frequency (RF) receive coil arrays using additive manufacturing. Our process involves spray deposition of silver nanoparticle inks and dielectric materials onto 3D printed substrates to form high-quality resonant circuits. In this paper, we describe the material selection and characterization, process optimization, and design and testing of a prototype 4-channel neck array for carotid imaging. We show that sprayed polystyrene can form a low loss dielectric layer in a parallel plate capacitor. We also demonstrate that by using sprayed silver nanoparticle ink as conductive traces, our devices are still dominated by sample noise, rather than material losses. These results are critical for maintaining high Signal-to-Noise-Ratio (SNR) in clinical settings. Finally, our prototype patient specific coil array exhibits higher SNR (5 × in the periphery, 1.4 × in the center) than a commercially available array designed to fit the majority of subjects when tested on our custom neck phantom. 3D printed substrates ensure an optimum fit to complex body parts, improve diagnostic image quality, and enable reproducible placement on subjects.

scholarly journals Numerical Analysis of a Flexible Dual Loop Coil and its Experimental Validation for pre-Clinical Magnetic Resonance Imaging of Rodents at 7 T

2016 ◽  
Vol 16 (6) ◽  
pp. 294-299 ◽  
Author(s):  
S. Solis-Najera ◽  
F. Vazquez ◽  
R. Hernandez ◽  
O. Marrufo ◽  
A.O. Rodriguez
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging System ◽  
Ex Vivo ◽  
Small Animal ◽  
Magnetic Resonance Imaging System ◽  
External Diameter ◽  
Rf Coil ◽  
Resonance Imaging ◽  
Clinical Magnetic Resonance Imaging

Abstract A surface radio frequency coil was developed for small animal image acquisition in a pre-clinical magnetic resonance imaging system at 7 T. A flexible coil composed of two circular loops was developed to closely cover the object to be imaged. Electromagnetic numerical simulations were performed to evaluate its performance before the coil construction. An analytical expression of the mutual inductance for the two circular loops as a function of the separation between them was derived and used to validate the simulations. The RF coil is composed of two circular loops with a 5 cm external diameter and was tuned to 300 MHz and 50 Ohms matched. The angle between the loops was varied and the Q factor was obtained from the S11 simulations for each angle. B1 homogeneity was also evaluated using the electromagnetic simulations. The coil prototype was designed and built considering the numerical simulation results. To show the feasibility of the coil and its performance, saline-solution phantom images were acquired. A correlation of the simulations and imaging experimental results was conducted showing a concordance of 0.88 for the B1 field. The best coil performance was obtained at the 90° aperture angle. A more realistic phantom was also built using a formaldehyde-fixed rat phantom for ex vivo imaging experiments. All images showed a good image quality revealing clearly defined anatomical details of an ex vivo rat.

scholarly journals Breathable Materials for Triboelectric Effect-Based Wearable Electronics

2018 ◽  
Vol 8 (12) ◽  
pp. 2485 ◽  
Author(s):  
Congju Li ◽  
Ran Cao ◽  
Xiuling Zhang
Keyword(s):  
Recent Progress ◽  
Dielectric Materials ◽  
Wearable Devices ◽  
Wearable Electronics ◽  
Practical Application ◽  
Metal Mesh ◽  
Frictional Materials ◽  
Nanofiber Membranes ◽  
Materials Used ◽  
Triboelectric Effect

Wearable electronics are believed to be the future of the next-generation electric devices. However, the comfort of current wearable devices is greatly limited due to the use of airtight materials, which may even lead to inflammation of the skin. Therefore, breathable, skin-friendly materials, are highly desired for wearable devices. Here, the recent progress of the breathable materials used to fabricate skin-friendly electronics is reviewed by taking triboelectric effect-based wearable electronics as a typical example. Fibers, yarns, textiles, and nanofiber membranes are the most popular dielectric materials that serve as frictional materials. Metal mesh, silver yarn, and conductive networks made up of nanomaterial are preferred as air-permissive electrodes. The breathable materials for skin-friendly wearable electronics summarized in this review provide valuable references for future fabrication of humanized wearable devices and hold great significance for the practical application of wearable devices.

scholarly journals Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0161863 ◽  
Author(s):  
Oliver Weinberger ◽  
Lukas Winter ◽  
Matthias A. Dieringer ◽  
Antje Els ◽  
Celal Oezerdem ◽  
...  
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Surface Coil ◽  
3 Tesla ◽  
Rf Coil
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