Development Of Rf Coils And Pulsing Methods For Nmr Mri

Development of RF Coils and Pulsing Methods for NMR/MRI

Radiofrequency magnetic (B1) field inhomogeneity and absorbed power in sample and RF coil have been among the main causes for image degradation in magnetic resonance imaging (MRI) since its inception. The problem becomes more pronounced at high frequencies as wavelengths in tissue become shorter. To address these problems, we present methods for design, implementation, and evaluation of RF coils considering excitation uniformity and/or specific absorption rate (SAR) for high field nuclear magnetic resonance (NMR) and MRI. Specifically, we present 1) the design of a novel radiofrequency (RF) coil for imaging of histological slices of tissue using a 7.0 T MRI system, 2) numerical model of a dielectric resonator for high field MRI, 3) a method to separate conservative and magnetically-induced electric fields from numerical calculations for MR microscopy, 4) a simple method to decrease sample heating using conductive wires, 5) a numerical analysis of conservative and magnetically-induced electric field for low-frequency human imaging, 6) numerical calculation results for the B1 field and SAR evaluation in a 3T neonate head coil, and 7) design of a slice-selective array-optimized composite pulse to improve B1 uniformity and reduce SAR using an 8-channel transmit head array loaded with a head model. The methods and results presented here can provide very useful information for designing RF coils considering excitation uniformity and SAR simultaneously in high field MRI/NMR.

Nuclear Magnetic Resonance

As a spectroscopic method, Nuclear Magnetic Resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an in valuable source of current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.

Nuclear Magnetic Resonance Spectroscopy in the Study of Neoplastic Tissue