TY - JOUR
T1 - Multiple-Quantum Filters of Spin- 3 2 with Pulses of Arbitrary Flip Angle
AU - Reddy, R.
AU - Shinnar, M.
AU - Wang, Z.
AU - Leigh, J. S.
PY - 1994
Y1 - 1994
N2 - The influence of inhomogeneous RF fields on the double- and triple-quantum filtering of spin- 3 2 nuclei in the presence of biexponential relaxation is analyzed. In this analysis, spherical tenser operators have been used for density-matrix calculations. In the presence of inhomogeneous RF fields, it is shown that the three pulse triple-quantum filter (TQF) without a refocusing 2θ pulse (with Δω = 0) is on average about 100% more sensitive than the corresponding double-quantum filter (DQF), and in the case of four-pulse DQF and TQF with a refocusing 2θ pulse (with Δω ≠ 0), two relaxation coefficients f(1) 11(τ) and f(1) 33(τ) also contribute to the observed DQ and TQ coherences. It is also shown that the three-pulse filters are more sensitive than the corresponding four-pulse filters. In both three- and four-pulse cases, when used with surface coils, these filters act as depth pulses and thus yield spatial localization. The experimental results obtained with homogeneous RF coils are in excellent agreement with the theoretical results.
AB - The influence of inhomogeneous RF fields on the double- and triple-quantum filtering of spin- 3 2 nuclei in the presence of biexponential relaxation is analyzed. In this analysis, spherical tenser operators have been used for density-matrix calculations. In the presence of inhomogeneous RF fields, it is shown that the three pulse triple-quantum filter (TQF) without a refocusing 2θ pulse (with Δω = 0) is on average about 100% more sensitive than the corresponding double-quantum filter (DQF), and in the case of four-pulse DQF and TQF with a refocusing 2θ pulse (with Δω ≠ 0), two relaxation coefficients f(1) 11(τ) and f(1) 33(τ) also contribute to the observed DQ and TQ coherences. It is also shown that the three-pulse filters are more sensitive than the corresponding four-pulse filters. In both three- and four-pulse cases, when used with surface coils, these filters act as depth pulses and thus yield spatial localization. The experimental results obtained with homogeneous RF coils are in excellent agreement with the theoretical results.
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U2 - 10.1006/jmrb.1994.1068
DO - 10.1006/jmrb.1994.1068
M3 - Article
C2 - 8049867
AN - SCOPUS:0028454138
SN - 1064-1866
VL - 104
SP - 148
EP - 152
JO - Journal of Magnetic Resonance, Series B
JF - Journal of Magnetic Resonance, Series B
IS - 2
ER -