Measurement of the magnetic field of an RF-encoding birdcage-coil design for magnetic resonance imaging
Magnetic Resonance Imaging (MRI) is a non-invasive imaging technique used in radiology to investigate the anatomy and physiology of the body in both health and disease. MRI currently depends on the use of magnetic field gradient coils to visualize tissue. However, there is an alternate method, which can only use RF to encode the image. The idea behind RF encoding is that it uses spatial phase variation in the RF transmission to encode spatial information in the MRI signal instead of using gradient magnetic fields. This alternate method of encoding with RF, without magnetic field gradients, allows for a much simpler hardware configuration for the MRI device. Therefore, it could become possible to design a cheaper and lighter portable MRI. In this study, a measurement device was designed and constructed for a DC model of an RF encoding birdcage coil design. When the appropriate currents were applied onto the legs of the coil, a magnetic field was generated as quantified by the Biot-Savart law. Herein we presumed that the wires are infinitely long. These currents were calculated according to the RF phase encoding method, aimed to produce a linear varying phase mapping along with one axis. By using the constructed measurement device, the experimental phase profile could be obtained. It was found that a linear spatial phase variation occurs along the axis, with the RF birdcage-coil setup. By comparing the theoretical phase map with the experimental, the difference was quantified. Then, we could reach the conclusion that the proposed RF coil design works as predicted by theory.
DegreeMaster of Science (M.Sc.)
SupervisorSarty, Gordon Eric; Bradley, Michael Patrick
CommitteeSarty, Gordon Eric; Bradley, Michael Patrick; Hussey, Glenn; Babyn , Paul; Odeshi , Akindele Gabriel; Sharp, Jonathan
Copyright DateJune 2016
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