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WIDEBAND STEADY-STATE FREE PRECESSION
FOR CARDIAC MRI
by
Hsu-Lei Lee
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(ELECTRICAL ENGINEERING)
December 2008
Copyright 2008 Hsu-Lei Lee
Object Description
| Title | Wideband steady-state free precession for cardiac MRI |
| Author | Lee, Hsu-Lei |
| Author email | hsulee@usc.edu; hsulei.lee@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Electrical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-10-08 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-12-04 |
| Advisor (committee chair) | Nayak, Krishna S. |
| Advisor (committee member) |
Leahy, Richard M. Reisler, Hanna |
| Abstract | Balanced steady-state free precession (SSFP) is an MRI pulse sequence that is widely used for cardiac imaging, because it provides superior SNR and excellent blood-myocardium contrast compared to the alternatives. Its primary drawback is sensitivity to off-resonance, which is related to the reciprocal of the sequence repetition time (TR) and results in banding artifacts.; In this thesis, I introduce a novel technique that overcomes this limitation, and apply it to two clinically important cardiac imaging applications. The new technique, called wideband SSFP, utilizes two alternating repetition times to establish a steady state that is more resistant to banding artifacts, because the spacing between nulls in its frequency response is up to twice as large as that of conventional balanced SSFP. Wideband SSFP provides an efficient scheme for acquiring SSFP cardiac images with long readouts, which allows the high SNR of SSFP to be used for achieving higher spatial resolution. This technique is particularly suited for higher field strengths (such as 3 Tesla).; A theoretical description of wideband SSFP is provided, including its spectral response, contrast, and SNR efficiency, with phantom experiments demonstrating excellent agreement between simulation and measurement. I then describe an initial magnetization preparation scheme based on scaled Kaiser-Bessel windowing functions to optimally stabilize the alternating-TR SSFP signal. Successful implementations of wideband SSFP for left ventricular function imaging and high-resolution coronary artery imaging in humans at 3 Tesla are then presented. In both cases, wideband SSFP provided improved spatial resolution and reduced image artifact, while maintaining a blood-myocardium contrast comparable to conventional balanced SSFP. |
| Keyword | alternating repetition times; coronary artery imaging; initial preparation; LV function; steady-state free precession; wideband SSFP |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m1866 |
| Rights | Lee, Hsu-Lei |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Lee-2399 |
| Archival file | uscthesesreloadpub_Volume32/etd-Lee-2399.pdf |
Description
| Title | Page 1 |
| Full text | WIDEBAND STEADY-STATE FREE PRECESSION FOR CARDIAC MRI by Hsu-Lei Lee A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (ELECTRICAL ENGINEERING) December 2008 Copyright 2008 Hsu-Lei Lee |
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