Sources of variability in the response of coupled spins to the PRESS sequence and their potential impact on metabolite quantification

Using a numerical method of solving the equation of motion of the density matrix, an evaluation is presented of the sources of the marked variability in the response to the point resolved spectroscopy (PRESS) pulse sequence of coupled proton spin systems. The consequences of an inappropriate 180° pulse design and of the limitations on radiofrequency power are demonstrated for a weakly coupled example, lactate. The dominating role of strong coupling, which is present in most brain metabolites, is demonstrated for glutamate, in which 160 terms in the density operator were tracked to monitor the gross changes in lineshape and signal intensity as a function of the two echo times. The predictions of the numerical solutions were confirmed by experiments on phantoms of aqueous metabolite solutions. Magn Reson Med 41:1162–1169, 1999. © 1999 Wiley‐Liss, Inc.

[1]  J A Sorenson,et al.  Localized 2D J‐resolved H MR spectroscopy of human brain tumors in vivo , 1996, Journal of magnetic resonance imaging : JMRI.

[2]  U. Klose,et al.  Lactate quantification by means of press spectroscopy--influence of refocusing pulses and timing scheme. , 1995, Magnetic resonance imaging.

[3]  S. Provencher Estimation of metabolite concentrations from localized in vivo proton NMR spectra , 1993, Magnetic resonance in medicine.

[4]  B. Meier,et al.  Computer Simulations in Magnetic Resonance. An Object-Oriented Programming Approach , 1994 .

[5]  O. Lutz,et al.  Polarization-transfer effects in localized double-spin-echo spectroscopy of weakly coupled homonuclear spin systems , 1995 .

[6]  J J Neil,et al.  Homonuclear J coupling effects in volume localized NMR spectroscopy: Pitfalls and solutions , 1998, Magnetic resonance in medicine.

[7]  P. Allen,et al.  A new multiple quantum filter design procedure for use on strongly coupled spin systems found in vivo: Its application to glutamate , 1998, Magnetic resonance in medicine.

[8]  Product operator theory for ABX spin systems and its application to H-C-C INEPT NMR experiments , 1994 .

[9]  I. Marshall,et al.  Calculations and experimental studies of the lineshape of the lactate doublet in PRESS‐localized 1H MRS , 1997, Magnetic resonance in medicine.

[10]  A. Wilman,et al.  An Analytical and Experimental Evaluation of STEAM versus PRESS for the Observation of the Lactate Doublet , 1993 .

[11]  B D Ross,et al.  Absolute Quantitation of Water and Metabolites in the Human Brain. II. Metabolite Concentrations , 1993 .

[12]  A H Wilman,et al.  Metabolite‐specific NMR spectroscopy in vivo , 1997, NMR in biomedicine.

[13]  W Dreher,et al.  On the use of two‐dimensional‐J NMR measurements for in Vivo proton MRS: Measurement of homonuclear decoupled spectra without the need for short echo times , 1995, Magnetic resonance in medicine.

[14]  P F Renshaw,et al.  In vivo detection of GABA in human brain using a localized double‐quantum filter technique , 1997, Magnetic resonance in medicine.

[15]  Shi-Jiang Li,et al.  Differentiation of metabolic concentrations between gray matter and white matter of human brain by in vivo 1H magnetic resonance spectroscopy , 1998, Magnetic resonance in medicine.

[16]  Jullie W Pan,et al.  Spectroscopic imaging of human brain glutamate by water‐suppressed J‐refocused coherence transfer at 4.1 T , 1996, Magnetic resonance in medicine.

[17]  J Hennig,et al.  Coupling effects in volume selective 1H spectroscopy of major brain metabolites , 1991, Magnetic resonance in medicine.

[18]  Jullie W Pan,et al.  Quantitative 1H spectroscopic imaging of human brain at 4.1 T using image segmentation , 1996, Magnetic resonance in medicine.

[19]  O Nalcioglu,et al.  Homonuclear J‐refocused spectral editing technique for quantification of glutamine and glutamate by 1H NMR spectroscopy , 1995, Magnetic resonance in medicine.

[20]  O. Lutz,et al.  Localized double-spin-echo proton spectroscopy of weakly coupled homonuclear spin systems , 1992 .

[21]  J. Slotboom,et al.  The Effects of Frequency-Selective RF Pulses on J-Coupled Spin- {1}/{2} Systems , 1994 .

[22]  Alan H. Wilman,et al.  ObservingN-Acetyl Aspartate via Both ItsN-Acetyl and Its Strongly Coupled Aspartate Groups inin VivoProton Magnetic Resonance Spectroscopy , 1996 .

[23]  L. Kay,et al.  A product operator description of AB and ABX spin systems , 1988 .

[24]  G B Matson,et al.  Measurement of chemical shifts and coupling constants for glutamate and glutamine , 1998, Magnetic resonance in medicine.

[25]  J. Sorenson,et al.  Localized 2D J-resolved 1H MR spectroscopy: strong coupling effects in vitro and in vivo. , 1995, Magnetic resonance imaging.

[26]  P. Carlier,et al.  Practical implementation of single‐voxel double‐quantum editing on a whole‐body NMR spectrometer: Localized monitoring of lactate in the human leg during and after exercise , 1996, Magnetic resonance in medicine.

[27]  W Dreher,et al.  Magnetization transfer affects the proton creatine/phosphocreatine signal intensity: In vivo demonstration in the rat brain , 1994, Magnetic resonance in medicine.

[28]  G. Bodenhausen,et al.  Principles of nuclear magnetic resonance in one and two dimensions , 1987 .

[29]  A. Wilman,et al.  The response of the strongly coupled AB system of citrate to typical 1H MRS localization sequences. , 1995, Journal of magnetic resonance. Series B.

[30]  J. R. Baker,et al.  A localized double‐quantum filter for the in vivo detection of brain glucose , 1998, Magnetic resonance in medicine.