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Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
Stabilization of alternating TR steady-state free precession sequences
1Ming Hsieh Department of Electrical Engineering, University of Southern California, 3740 McClintock Avenue EEB 412, Los Angeles, CA 90007, USA. hsulee@usc.edu
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|October 10, 2008
Summary
Researchers developed a new preparation method to reduce signal fluctuations in alternating TR steady-state free precession (ATR SSFP) imaging. This technique significantly minimizes initial signal oscillations, improving image quality for ATR SSFP applications.
Area of Science:
- Magnetic Resonance Imaging
- Biomedical Engineering
- Signal Processing
Background:
- Conventional balanced steady-state free precession (SSFP) and alternating TR SSFP (ATR SSFP) exhibit transient signal oscillations that can degrade image quality.
- Efficient preparation schemes are needed to mitigate these initial signal fluctuations in ATR SSFP sequences.
Purpose of the Study:
- To develop and validate an efficient preparation scheme for ATR SSFP sequences to reduce transient signal oscillations.
- To mathematically model ATR SSFP sequences and establish a relationship between preparation parameters and oscillatory residues.
Main Methods:
- A mathematical model for ATR SSFP sequences was constructed, adapting methods used for conventional SSFP.
- A Fourier relation was derived between odd/even RF flip angle terms and oscillatory residues.
- A weighted Kaiser-Bessel windowed ramp was designed for preparation schemes with arbitrary TR(1), TR(2), and RF phase cycling.
- Optimized preparations were tested in phantoms for wideband SSFP and fat-suppressed ATR SSFP imaging.
Main Results:
- The developed mathematical model provides a Fourier relationship for understanding signal oscillations.
- Weighted Kaiser-Bessel windowed ramp preparations effectively reduce transient signal oscillations.
- Optimized preparations demonstrated substantial reduction in signal fluctuation in phantom studies.
Conclusions:
- The proposed weighted Kaiser-Bessel windowed ramp preparation is an effective method for reducing transient signal oscillations in ATR SSFP imaging.
- This technique can improve image quality in various ATR SSFP applications, including wideband and fat-suppressed imaging.
- The mathematical framework provides a basis for designing optimized preparation schemes for SSFP sequences.
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