Restoration of motion‐related signal loss and line‐shape deterioration of proton MR spectra using the residual water as intrinsic reference

A postprocessing method to restore motion‐related signal loss and line‐shape deterioration in single‐volume proton MR spectroscopy (MRS) is presented. Each acquisition is corrected by its phase offset and frequency shift, extracted from the residual water signal prior to averaging. Requirements are good gradient selection and selective suppression of CSF in residual water. Stimulated echo acquisition mode (STEAM) spectra (TE = 30 ms) were analyzed using the LCModel program to study gains in metabolite signal and spectral quality in five brain regions. Increases of total N‐acetyl‐aspartate concentrations of up to 5% were observed. The method may be beneficial for clinical examinations of less compliant subjects and for dynamic spectroscopy. Magn Reson Med 46:395‐400, 2001. © 2001 Wiley‐Liss, Inc.

[1]  P. Allen,et al.  Motional degradation of metabolite signal strengths when using STEAM: A correction method , 1992, NMR in biomedicine.

[2]  N Sailasuta,et al.  Proton spectroscopy without water suppression: The oversampled J‐resolved experiment , 1998, Magnetic resonance in medicine.

[3]  G Helms,et al.  A precise and user‐independent quantification technique for regional comparison of single volume proton MR spectroscopy of the human brain , 2000, NMR in biomedicine.

[4]  D. Greitz,et al.  Cerebrospinal fluid circulation and associated intracranial dynamics. A radiologic investigation using MR imaging and radionuclide cisternography. , 1993, Acta radiologica. Supplementum.

[5]  I Savic,et al.  MR Spectroscopy Shows Reduced Frontal Lobe Concentrations of N‐Acetyl Aspartate in Patients with Juvenile Myoclonic Epilepsy , 2000, Epilepsia.

[6]  L Vanhamme,et al.  New approach for quantitation of short echo time in vivo 1H MR spectra of brain using AMARES , 1998, NMR in biomedicine.

[7]  U. Klose.  In vivo proton spectroscopy in presence of eddy currents , 1990, Magnetic resonance in medicine.

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

[9]  C Boesch,et al.  Versatile frequency domain fitting using time domain models and prior knowledge , 1998, Magnetic resonance in medicine.

[10]  P G Webb,et al.  Automated single‐voxel proton MRS: Technical development and multisite verification , 1994, Magnetic resonance in medicine.

[11]  I. Wickbom.  The influence of the blood pressure in urographic examination; preliminary report. , 1950, Acta radiologica.

[12]  G Helms,et al.  Analysis of 1.5 Tesla proton MR spectra of human brain using LCModel and an imported basis set. , 1999, Magnetic resonance imaging.

[13]  R. Kreis,et al.  Effects of physiologic motion of the human brain upon quantitative 1H‐MRS: analysis and correction by retro‐gating , 1998, NMR in biomedicine.

[14]  A. D. de Graaf,et al.  Quality: quantification improvement by converting lineshapes to the lorentzian type , 1990, Magnetic resonance in medicine.