Abstract
The influence of pulse angle variations in the localization sequence stimulated echo acquisition mode (STEAM) on the signal of strongly coupled AB spin systems has been examined. Experimental1H nuclear magnetic resonance (NMR) spectra of citrate were recorded on a 1.5 T whole-body imager. Theoretically calculated spectra were generated, with good correlation to experimental results. The dependence of the signal intensity on sequence timing and pulse angles was calculated analytically. For longer sequence timings, the ratio of the signal intensity from citrate to the signal intensity from uncoupled nuclei depends strongly on the applied flip angles. The shape of spectra also changes with varying flip angles. These effects are clearly less pronounced for STEAM than for point resolved spectroscopy (PRESS). The results have to be considered for quantitative measurements of citrate in spectroscopic investigations as, e.g. of prostate neoplasms.
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Fowler AH, Pappas AA, Holder JC, et al. Differentiation of human prostate cancer from benign hypertrophy by in vitro1H NMR. Magn Reson Med 1992;25:140–7.
Schick F, Bongers H, Kurz S, Jung W-I, Pfeffer M, Lutz O. Localized proton MR spectroscopy of citrate in vitro and of the human prostate in vivo at 1.5 T. Magn Reson Med 1993;29:38–43.
Kurhanewicz J, Dahiya R, Macdonald JM, Chang LH, James TL, Narayan P. Citrate alterations in primary and metastatic human and biochemical study. Magn Reson 1993;29:149–57.
Kurhanewicz J, Vigneron DB, Nelson SJ, Hricak H, Carrol P, Narayan P. High resolution STEAM and PRESS 3-D proton spectroscopic imaging of the prostate. Proceedings. SMR, Second Meeting. Berkely, CA: Society of Magnetic Resonance, 1994:273.
Lowry M, Manton DJ, Turnbull LW, Blackband SJ, Horsman A. Quantitative proton MRS assessment of citrate heterogeneity in normal prostate. MAGMA 1994;2:483–5.
Heerschap A, Jager GJ, van der Graaf M, et al. In vivo proton MR spectroscopy reveals altered metabolite content in malignant prostate tissue. Anticancer Res 1994;17:1455–60.
Chandrakumar N, Subramanian S. Modern techniques in high-resolution FT-NMR. New York, Berlin, Heidelberg: Springer-Verlag, 1987.
Gordon RE, Ordidge RJ. Volume selection for high resolution NMR studies. Scientific Program, SMRM, Third Annual Meeting, New York. Berkely, CA: Society of Magnetic Resonance in Medicine, 1984:272–3.
Bottomley PA. Spatial localization in NMR spectroscopy in vivo. Ann NY Acad Sci 1987;508:333–48.
Granol J. Selectled volume excitation using stimulated echoes (VEST). Applications to spatially localized spectroscopy and imaging. J Magn Reson 1986;70:488–92.
Kimmich R, Hoepfel D. Volume-selective multipulse spin-echo spectroscopy. J Magn Reson 1986;72:379–84.
Frahm J, Merboldt KD, Hanicke W. Localized proton spectroscopy using stimulated echoes. J Magn Reson 1987;72:502–8.
Hentschel D, Ladebeck R. In vivo localized1H-spectroscopy with spin echos and stimulated echos: a quantitative comparison. Appl Magn Reson 1987;1:41–6.
Geen H, Freeman R. Band-selective radio frequency pulses. J Magn Reson 1991;93:93–141.
Brown TR, Kincaid BM, Uğurbil K. NMR chemical shift imaging in three dimensions. Proc Natl Acad Sci USA 1982;79:3523–6.
Jung W-I, Lutz O. Localized double-spin-echo proton spectroscopy of weakly coupled homonuclear spin systems. J Magn Reson 1992;96:237–51.
Bunse M, Jung WI, Lutz O, Kupper K, Dietze G. Polarization-transfer effects in localized double-spin-echo spectroscopy of weakly coupled homonuclear spin systems. J Magn Reson 1995;114:230–7.
Powles JG, Hartland A. The measurement of indirect (J) coupling between nuclei in liquids in magnetic resonance by tne transient method. Proc Phys Soc (Lond) 1961;77:273–7.
Mulkern RV, Bowers JL. Calculating spectral modulations of AB systems during PRESS acquisitions. Magn Reson Med 1993;30:518–9
Wilman AH, Allen PS. The response of the strongly coupled AB system of citrate to typical1H MRS localization sequences. J Magn Reson B 1995:107:25–33.
Mulkern RV, Bowers JL. Density matrix calculations of AB spectra from multipulse sequences: quantum mechanics meets in vivo spectroscopy. Concepts Magn Reson 1994;6:1–23.
Straubinger K, Schick F, Lutz O. Computer-algebra calculations and measurements on AB spin systems for double-spin-echo sequences. MAGMA 1995;3:109–18.
Mulkern RV, Bowers JL, Peled S, Williamson DS. Density-matrix calculations of the 1.5T citrate signal acquired with volume-localized STEAM sequences. J Magn Reson B 1996;110:255–66.
Straubinger K, Schick F, Lutz O. Relaxation of AB spin systems in stimulated-echo spectroscopy. J Magn Reson B 1995;109:251–8.
Straubinger K, Schick F, Lutz O. Pulse angle dependence of double spin-echo proton NMR spectra of citrate-theory and experiments. J Magn Reson B 1996;110:188–94.
Homans SW. A dictioary of concepts in NMR. Oxford: Clarendon Press, 1989.
Wilman AH, Allen PS. An analytical and experimental evaluation of STEAM versus PRESS for the observation of the lactate doublet. J Magn Reson B 1993;101:102–5.
Char BW, Geddes KO, Gonnet GH, Leong BL, Monagan MB, Watt SM. Maple V language reference manual. New York, Berlin, Heidelberg: Springer Verlag, 1991.
Wolfram S. Mathematica: a system for doing mathematics by computer. 2nd edn. Redwood City, CA: Addison-Wesley, 1991.
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Straubinger, K., Schick, F. & Lutz, O. Influence of pulse angle variations onstimulated echo acquisition mode proton nuclear magnetic resonance spectra of AB spin systems: theory and experiments with citrate. MAGMA 7, 88–94 (1998). https://doi.org/10.1007/BF02592233
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DOI: https://doi.org/10.1007/BF02592233