Rational approaches to the design of NMR selective pulses

The need for NMR selective pulses in magnetic resonance imaging and spectroscopy is reviewed. The shortcomings of the current generation of pulses are discussed and the need for new categories of pulse identified. Strategies for selective pulse design are outlined and two numerical optimization methods, simulated annealing and SPINCALC (a method recently introduced by us: J. T. Ngo and P. G. Morris, Magn. Reson. Med. 5, 217 (1987)), are discussed in detail. Their use is illustrated and compared for the design of π/2 phase‐compensated pulses. Both methods require substantial amounts of CPU time, with simulated annealing the more demanding. Unconstrained, simulated annealing also tends to produce pulses with discontinuous waveforms. A crude two‐dimensional pulse derived from a low flip angle approximation is illustrated.

[1]  A. Haase,et al.  Rapid NMR Imaging Using Low Flip-Angle Pulses , 2004 .

[2]  J T Ngo,et al.  General solution to the NMR excitation problem for noninteracting spins , 1987, Magnetic resonance in medicine.

[3]  P. J. Hore,et al.  Solvent suppression in Fourier transform nuclear magnetic resonance , 1983 .

[4]  P G Morris,et al.  Human whole body line-scan imaging by NMR. , 1978, The British journal of radiology.

[5]  P. Luyten,et al.  Solvent-suppressed spatially resolved spectroscopy. An approach to high-resolution NMR on a whole-body MR system , 1986 .

[6]  Graeme M. Bydder,et al.  Localized phosphorus-31 NMR spectroscopy of normal and pathological human organs in vivo using phase-encoding techniques , 1987 .

[7]  Matthew O'Donnell,et al.  Optimization of two-dimensional spatially selective NMR pulses by simulated annealing , 1988 .

[8]  R. E. Gordon,et al.  The use of high-order gradients to vary the spatial extent of B0 homogeneity in a high-resolution NMR experiment , 1981 .

[9]  W. Hinshaw,et al.  Image formation by nuclear magnetic resonance: The sensitive‐point method , 1976 .

[10]  J. T. Ngo,et al.  A new method for the optimization of nuclear magnetic resonance selective excitation pulses , 1986 .

[11]  Roger J. Ordidge,et al.  Image-selected in Vivo spectroscopy (ISIS). A new technique for spatially selective nmr spectroscopy , 1986 .

[12]  Ray Freeman,et al.  Shaped selective pulses for coherence-transfer experiments , 1987 .

[13]  S Müller,et al.  Volume-selective excitation. A novel approach to topical NMR , 1984 .

[14]  A. Pines,et al.  Broadband population inversion by phase modulated pulses , 1983 .

[15]  R. Kimmich,et al.  Volume-selective multipulse spin-echo spectroscopy , 1987 .

[16]  Roger J. Ordidge,et al.  Outer volume suppressed image related in vivo spectroscopy (OSIRIS), a high-sensitivity localization technique , 1988 .

[17]  G. Radda,et al.  Spatial localization of high resolution 31P spectra with a surface coil , 1983 .

[18]  Joseph Granot,et al.  Selected Volume Excitation Using Stimulated Echoes (VEST). Applications to spatially localized spectroscopy and imaging , 1986 .

[19]  D. Hoult,et al.  Selective population inversion in NMR , 1984, Nature.

[20]  P. Mansfield,et al.  NMR 'diffraction' in solids? , 1973 .

[21]  E. R. Andrew,et al.  NMR Imaging in Medicine and Biology , 1979 .

[22]  J. Koutcher,et al.  Field focusing nuclear magnetic resonance (FONAR): visualization of a tumor in a live animal. , 1976, Science.

[23]  P. Lauterbur,et al.  Image Formation by Induced Local Interactions: Examples Employing Nuclear Magnetic Resonance , 1973, Nature.

[24]  P. Locher.  Computer simulation of selective excitation in n.m.r. imaging. , 1980, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[25]  C. D. Gelatt,et al.  Optimization by Simulated Annealing , 1983, Science.

[26]  D. Gadian,et al.  Mapping of metabolites in whole animals by 31P NMR using surface coils , 1980, Nature.

[27]  T. Jue.  Parsing the edited 13C-1H and 12C-1H signals into subspertra , 1988 .

[28]  G. Bodenhausen,et al.  Self‐refocusing 270° gaussian pulses for slice selection without gradient reversal in magnetic resonance imaging , 1989, Magnetic resonance in medicine.

[29]  Peter Mansfield,et al.  Fast scan proton density imaging by NMR , 1976 .

[30]  P. Mansfield.  Multi-planar image formation using NMR spin echoes , 1977 .

[31]  D. Doddrell,et al.  Spatial and chemical-shift-encoded excitation. SPACE, a new technique for volume-selected NMR spectroscopy , 1986 .

[32]  P. Mansfield,et al.  Image formation in NMR by a selective irradiative process , 1974 .

[33]  S. Ljunggren.  A simple graphical representation of fourier-based imaging methods , 1983 .