Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 14 of 14 for “"RF Coil"”.
-
Fast magnetic resonance spectroscopic imaging using RF coil arrays
… times. The development of high-fidelity gradient coils has opened opportunities for fast k-space encoding schemes that are already used in structural imaging. At the same time, receive-coil arrays using 4 and 23 channels have been developed and reported to produce improved SNR over conventional …
-
A 24-channel radio frequency receive array for magnetic resonance imaging of primates at 10.5 T
… other imaging technologies. The radio frequency (RF) coil is one of the key hardware sub-systems, which drives overall MRI system performance to enable higher resolution imaging and the collection of high fidelity information about organism structure and function. To optimize RF coil performance, …
-
Radiofrequency detector coil performance maps for parallel MRI applications
… In parallel MRI, arrays of radiofrequency (RF) detector coil arrays are used to perform some degree of spatial encoding which complements traditional encoding using magnetic field gradients. As the acceleration factor increases, coil design becomes critical to the overall image quality. The …
-
Radiofrequency losses in an NMR surface coil
… loss has been investigated for a resonant NMR surface coil between 20 MHz and 400 MHz. High-field NMR (> 64 MHz) is used increasingly for human imaging and spectroscopy to achieve improved SNR and spectral resolution. RF losses in coils designed using conventional lumped-element principles, …
-
Model Validation and Inversion of Active Implantable Medical Devices
… resonance imaging (MRI) radio frequency (RF) coil emission were discussed. A mathematical derivation is presented to provide guidance on selecting meaningful pathways for the model validation. Suggested validation pathways from current ISO 10974 are used as examples. It is shown that these …
-
Coil performance evaluation based on electrodynamics : tools for hardware design and validation in magnetic resonance imaging
… speed limits. In parallel MRI, radiofrequency (RF) detector coil arrays are used to perform some degree of spatial encoding which complements traditional encoding using magnetic field gradients. As the acceleration factor increases, coil design becomes critical to the overall image quality. The …
-
Advances in Sensitivity and Resolution of Solid State Nuclear Magnetic Resonance and Dynamic Nuclear Polarization
… Dynamic nuclear polarization (DNP) is a powerful method of enhancing solid state NMR sensitivity. However, this sensitivity gain comes at a significant loss of spectral resolution due to sample conformational heterogeneity at the cryogenic temperatures required for efficient electron-nuclear …
-
Nuclear magnetic resonance microscopy
… is equipped with a highly efficient. solenoidal RF coil and three orthogonal gradients with strengths of 1260G / cm for Gz , 760G/cm for Gy , and 410G/cm for Gx at 15A. A modified CTI sequence is presented which incorporates strong pulsed gradients, Ernst angle excitation, CP coherent detection …
-
Diagnostics and modelling of an inductively coupled RF low-pressure low-temperature plasma
… inductively coupled plasma using the external coil configuration used in the experimental work. Given fixed external RF coil current and voltage and the measured plasma density profile, Maxwell's equations and magnetohydrodynamical (MHD) fluid equations are used to calculate the self-consistent …
-
Methods and adaptations required to perform small-animal MRI scanning using a large bore clinical MRI
… project was to adapt a clinical MRI system to perform small-animal cardiac MRI. The first part of the thesis describes the adaptations required, which included design and construction of a small-animal radiofrequency (RF) coil, physical support (cradle), a core body temperature regulation system, …
-
Study of the thermal effects induced by magnetic resonance on endocardial leads: numerical models and experimental validation
… increase caused by the radiofrequency (RF) field generated during MRI procedures in the tissues surrounding thin metallic implants. On the other side, the technical evolution of MRI scanners and of AIMDs together with published data on the lack of adverse events have reopened the …
-
Plasma diagnostics and ITO film deposition by RF-assisted closed-field dual magnetron system
… materials. For this purpose, we developed an RF-assisted closed-field dual magnetron sputtering system. The “prototype” system consists of a 3-inch unbalanced dual magnetron operated at a closed-field configuration. An RF coil was fabricated and placed between the two magnetron cathodes to …
-
Strategies for Artifact Correction and Motion Monitoring in MRI Through Innovations in Radiofrequency Coil Design
… strategies using innovations in radio-frequency (RF) coil design to address the problems that arise when these assumptions are broken. </p><p>Typically, B_0 inhomogeneities are caused by susceptibility differences at air/tissue interfaces and result in image artifacts such as geometric distortions …
-
Effective Methods To Reduce The RF-Induced Heating For Medical Implants In MRI
Radiofrequency (RF) –induced heating is one of the primary safety concerns for patients with medical implants undergoing magnetic resonance imaging (MRI). Due to this potential hazard, patients with medical devices are usually contraindicated from the MRI process. With the steady growth in the …