Multichannel Radio-Frequency Receiver Systems for Magnetic Resonance Imaging
Date Issued
2014
Date
2014
Author(s)
Chu, Ying-Hua
Abstract
This research aims at developing multi-channel radio-frequency (RF) receiver systems. In the first part of the thesis, I developed a 32-channel 3T head coil array with circular symmetric (CS) geometry tailored for 1D and 2D accelerated acquisitions and image reconstructions. Compared to a commercial 32-channel head coil array with soccer-ball geometry (SB array), the CS array has higher signal-to-noise ratio (SNR) and lower reconstruction image noise amplification (g-factor) in accelerated acquisitions. The SNR in the CS array was about 236% and 80% of the SB array at the periphery and the center of the FOV, respectively. The second part of the thesis summarizes the efforts of developing field probe systems. Field probe systems can monitor magnetic field fluctuation caused by imperfect gradients, and eddy current. The information can be used to correct k-space trajectory. Images acquired from a spiral k-space trajectory were used to demonstrate the effectiveness of our field probe system by comparing the image reconstructed with/without the measured k-space trajectory. We also present a novel transceiver field probe system to allow high quality monitoring local magnetic field disturbances dynamically at the same frequency of the imaging object with minimized interferences. In conclusion, the CS array can be a helpful tool to provide high quality images of the human brain in accelerated MRI acquisitions. Field probe systems are useful tools in calibrating the k-space trajectory.
Subjects
相位線圈
SENSE
射頻接收線圈
磁共振平行影像
場偵測器
k空間軌跡
Type
thesis
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