Spoiling of transverse magnetization in steady‐state sequences
- 1 October 1991
- journal article
- research article
- Published by Wiley in Magnetic Resonance in Medicine
- Vol. 21 (2) , 251-263
- https://doi.org/10.1002/mrm.1910210210
Abstract
A detailed analysis is presented of a method to eliminate transverse magnetization prior to each rf excitation in pulse sequences with TR < T2. It is shown that artifact‐free images with high T1 contrast can be obtained only if a phase shift that is incremented during each TR interval is applied to the transverse magnetization. Computer simulations are used to show that when this phase increment is 117°, the steady‐state transverse magnetization prior to each rf pulse is nulled over a wide range of T1, T2, and rf tip angles, resulting in optimal T1, contrast. Such nulling of steady‐state transverse magnetization cannot be obtained by using large gradient pulses, or gradients of random or linearly incremented amplitude. Images of phantoms and human subjects confirm the theoretical predictions. © 1991 Academic Press, Inc.Keywords
This publication has 18 references indexed in Scilit:
- Motion‐insensitive, steady‐state free precession imagingMagnetic Resonance in Medicine, 1990
- The influence of flow and motion in MRI of diffusion using a modified CE‐FAST sequenceMagnetic Resonance in Medicine, 1989
- Artifacts due to residual magnetization in three‐dimensional magnetic resonance imagingMedical Physics, 1988
- Multiecho imaging sequences with low refocusing flip anglesJournal of Magnetic Resonance (1969), 1988
- T2‐weighted contrasts in rapid low flip‐angle imagingMagnetic Resonance in Medicine, 1987
- Transverse coherence in rapid FLASH NMR imagingJournal of Magnetic Resonance (1969), 1987
- A phase-cycling technique for canceling spurious echoes in NMR imagingJournal of Magnetic Resonance (1969), 1987
- FLASH imaging. Rapid NMR imaging using low flip-angle pulsesJournal of Magnetic Resonance (1969), 1986
- Signal, Noise, and Contrast in Nuclear Magnetic Resonance (NMR) ImagingJournal of Computer Assisted Tomography, 1983
- Phase and intensity anomalies in fourier transform NMRJournal of Magnetic Resonance (1969), 1971