Theory and design of synthesis array coils for magneitc resonance imaging /
Use of arrays of receiver coils in magnetic resonance imaging
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1996.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739667661&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Use of arrays of receiver coils in magnetic resonance imaging (MRI) improves signal-to-noise ratio (SNR) and extends field-of-view (FOV). It has been claimed in earlier publications that an ultimate limit for the SNR exists, and results for the special case of a lossy half space under quasi static conditions have been given. Theoretically, this ultimate limit will be reached for an ideal array of infinitely many infinitesimal coils, covering the entire surface of the lossy test sample. In this dissertation, the ultimate limit of the SNR for an infinite half space using quasi statics has been confirmed. Using a similar model, the ultimate SNR for a planar array wrapped around an infinite lossy cylinder has been established. Results for ultimate SNR values are used for comparison with discrete arrays, and the effects of additional losses and noise correlation on the obtainable SNR have been studied. Three array coil designs are presented and their potential use in MRI evaluated: A circular polarized (CP) dual channel transmit-receive head- neck array, a local 3 channel receiver array which can be used together with a CP transmit-receive coil for imaging of the head, and a 16 channel head array for functional MRI (fMRI). All three coils have been used in clinical studies and results obtained are shown in comparison with typical present state-of-the-art single channel MRI. |
|---|---|
| Item Description: | Vita. "Major Subject: Electrical Engineering". |
| Physical Description: | xxiii, 265 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 217-222. |