Theoretical and experimental results are presented demonstrating that the slice intensity resulting from a self-refocusing 270" Gaussian pulse (L. Elmsley and G. Bodenhausen, Magn. Reson. in Med. 10, 273, 1989) is approximately 60% of that following an appropriately refocused 90" GaUSSian pulse.
The design of practical selective pulses for magnetic resonance imaging and spectroscopy using SPINCALC
β Scribed by Peter G. Morris; Dominick J. O. McIntyre; David E. Rourke; J. Thomas Ngo
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 461 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
β¦ Synopsis
Recently, we introduced a new numerical approach to the design and optimization of NMR selective pulses, which we have christened "SPINCALC" (J. T. Ngo and P. G. Morris, Biochem. Soc. Trans. 14, 1271 (1986); J. T. Ngo and P. G. Morris, Magn. Reson. Med. 5, 217 (1987]. The first practical application of pulses generated by SPINCALC is demonstrated on a standard 0.5-T clinical MRI system. Results are shown for single phase pi pulses suitable both for selective inversion and for selective refocusing. The extension of SPINCALC to multidimensional pulses is illustrated by the design of a two-dimensional pi pulse.
π SIMILAR VOLUMES
A new theoretical method is presented for designing frequency responses of double-tuned, low-pass birdcage coils. This method is based on Kirchhoff's equations through a nonsymmetric matrix algorithm and extended through a modification of the corresponding eigenvalue system from a single-tuned mode.
## Abstract Threeβdimensional methods offer volumetric coverage in coronary vessel wall imaging, in addition to high signalβtoβnoise ratios (SNR). To increase SNR further, it is desirable to implement such 3D methods at 3 T. At this field strength, the pulse sequence must be robust to main field an