Most in vivo 31P MR studies are realized on 3T MR systems that provide sufficient signal intensity for prominent phosphorus metabolites. The identification of these metabolites in the in vivo spectra is performed by comparing their chemical shifts with the chemical shifts measured in vitro on high-field NMR spectrometers. To approach in vivo conditions at 3T, a set of phantoms with defined metabolite solutions were measured in a 3T whole-body MR system at 7.0 and 7.5 pH, at 37 °C. A free induction decay (FID) sequence with and without 1H decoupling was used. Chemical shifts were obtained of phosphoenolpyruvate (PEP), phosphatidylcholine (PtdC), phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), glycerophosphoetanolamine (GPE), uridine diphosphoglucose (UDPG), glucose-6-phosphate (G6P), glucose-1-phosphate (G1P), 2,3-diphosphoglycerate (2,3-DPG), nicotinamide adenine dinucleotide (NADH and NAD+), phosphocreatine (PCr), adenosine triphosphate (ATP), adenosine diphosphate (ADP), and inorganic phosphate (Pi). The measured chemical shifts were used to construct a basis set of 31P MR spectra for the evaluation of 31P in vivo spectra of muscle and the liver using LCModel software (linear combination model). Prior knowledge was successfully employed in the analysis of previously acquired in vivo data.

• Keywords
• 31P MRS, LCModel, in vivo MR spectroscopy, liver, muscle,
• MeSH
• Adenosine Diphosphate metabolism   MeSH
• Adenosine Triphosphate metabolism   MeSH
• Phosphatidylcholines metabolism   MeSH
• Phosphatidylethanolamines metabolism   MeSH
• Phosphates metabolism   MeSH
• Phosphorus metabolism   MeSH
• Liver metabolism   MeSH
• Muscle, Skeletal metabolism   MeSH
• Humans MeSH
• Nuclear Magnetic Resonance, Biomolecular * MeSH
• Pilot Projects MeSH
• Software * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Adenosine Diphosphate MeSH
• Adenosine Triphosphate MeSH
• Phosphatidylcholines MeSH
• Phosphatidylethanolamines MeSH
• Phosphates MeSH
• Phosphorus MeSH

PURPOSE: To introduce a method of independent determination of CH2 and CH3 components of intramyocellular lipids (IMCLs) by using long TE for spectra measurement and LCModel for spectra evaluation, to test this technique in controls and insulin-resistant subjects, and to compare results at 1.5 and 3 T. MATERIALS AND METHODS: Eight healthy volunteers and 11 patients with type 2 diabetes mellitus underwent measurement using a 1.5-T MR scanner; six healthy volunteers were measured using a 3-T MR scanner. Spectra from the tibialis anterior muscle were acquired by using a point resolved spectroscopy (PRESS) sequence with the following parameters: TR/TE/ACQ = 2000 msec/270 msec/256. Spectra were processed by LCModel 6.1 software with two types of adopted basis-set. RESULTS: Spectra with good separation of both CH2 and CH3 components of IMCL and extramyocellular lipids (EMCLs) were obtained and the LCModel routine was successfully applied. The reproducibility comparison (N= 7 at 1.5 T vs. N = 5 at 3 T) showed that better results can be obtained at higher B0 values. The comparison of the healthy and insulin-resistant subjects proved that both IMCL_CH2/Cr and IMCL_CH3/Cr ratios significantly differ. CONCLUSION: Long TE spectroscopy of the human muscle with IMCL quantification using the LCModel technique can detect changes in IMCL levels as well as help in the study of fatty acyl chain composition. Using a higher field strength increased the intra-individual reproducibility by approximately 150%.

• MeSH
• Algorithms * MeSH
• Analysis of Variance MeSH
• Models, Biological * MeSH
• Time Factors MeSH
• Diabetes Mellitus metabolism   MeSH
• Adult MeSH
• Image Interpretation, Computer-Assisted MeSH
• Muscle, Skeletal metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetics * MeSH
• Lipid Metabolism * physiology   MeSH
• Reference Values MeSH
• Reproducibility of Results MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Controlled Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

The linear combination of model spectra (LCModel) calculation of a parameter for long-term quality control, kT, was introduced, representing the ratio of the temporal and nominal intensities of CH3 groups of lactate and acetate in a quality control phantom. This procedure is a part of the quality assurance of the scanner using fully automatic measurement and calculation of kT parameters, and utilizing Shewhart regulation control charts for continuous evaluation of the magnetic resonance (MR) scanner setting. The application of the kT parameter for the correction of in vivo data increases the precision of molar concentration determination by about 4%. This was tested by the quantitative in vivo MR determination of the molar concentrations of 13 prominent metabolites (N-acetylaspartate (NAA), N-acetylaspartylglutamate, creatine and phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol, scyllo-inositol, gamma-aminobutyric acid, glutamine, glutamate, glucose, lactate, alanine, taurine) in the white matter and hippocampus of the brain in groups of volunteers, using a short echo time stimulated echo acquisition mode sequence (echo time = 10 ms) and the LCModel technique. The repeatability of the measurement of prominent metabolites such as NAA, Cr and Cho was found to be around 10% (relative standard deviation, n = 6); precision in a group of volunteers (n = 20 and 28, respectively) was in the range of approximately 13-20%. For other metabolites, which are measured with a lower signal-to-noise ratio, the precision can be much lower.

• MeSH
• Acetates metabolism   MeSH
• Amino Acids metabolism   MeSH
• Adult MeSH
• Phantoms, Imaging * MeSH
• Hippocampus metabolism   MeSH
• Calibration MeSH
• Lactates metabolism   MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   standards   MeSH
• Brain metabolism   MeSH
• Quality Control MeSH
• Auditory Cortex metabolism   MeSH
• Hydrogen MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Acetates MeSH
• Amino Acids MeSH
• Lactates MeSH
• Hydrogen MeSH

1H MR spectroscopy is routinely used for lateralization of epileptogenic lesions. The present study deals with the role of relaxation time corrections for the quantitative evaluation of long (TE=135 ms) and short echo time (TE=10 ms) 1H MR spectra of the hippocampus using two methods (operator-guided NUMARIS and LCModel programs). Spectra of left and right hippocampi of 14 volunteers and 14 patients with epilepsy were obtained by PRESS (TR/TE=5000/135 ms) and STEAM (TR/TE=5000/10 ms) sequences with a 1.5-T imager. Evaluation was carried out using Siemens NUMARIS software and the results were compared with data from LCModel processing software. No significant differences between the two methods of processing spectra with TE=135 ms were found. The range of relaxation corrections was determined. Metabolite concentrations in hippocampi calculated from spectra with TE=135 ms and 10 ms after application of correction coefficients did not differ in the range of errors and agreed with published data (135 ms/10 ms: NAA=10.2+/-0.6/10.4+/-1.3 mM, Cho=2.4+/-0.1/2.7+/-0.3 mM, Cr=12.2+/-1.3/11.3+/-1.3 mM). When relaxation time corrections were applied, quantitative results from short and long echo time evaluation with LCModel were in agreement. Signal intensity ratios obtained from long echo time spectra by NUMARIS operator-guided processing also agreed with the LCModel results.

• MeSH
• Algorithms * MeSH
• Models, Biological * MeSH
• Choline metabolism   MeSH
• Diagnosis, Computer-Assisted methods   MeSH
• Adult MeSH
• Epilepsy, Temporal Lobe diagnosis   metabolism   MeSH
• Hippocampus metabolism   MeSH
• Image Interpretation, Computer-Assisted MeSH
• Creatine metabolism   MeSH
• Aspartic Acid analogs & derivatives   metabolism   MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Brain Mapping methods   MeSH
• Nerve Tissue Proteins metabolism   MeSH
• Protons MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Subtraction Technique MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH
• Comparative Study MeSH
• Validation Study MeSH
• Names of Substances
• Choline MeSH
• Creatine MeSH
• Aspartic Acid MeSH
• N-acetylaspartate MeSH Browser
• Nerve Tissue Proteins MeSH
• Protons MeSH

PURPOSE: To understand how macromolecular content varies in the human brain with age in a large cohort of healthy subjects. METHODS: In-vivo 1H-MR spectra were acquired using ultra-short TE STEAM at 7T in the posterior cingulate cortex. Macromolecular content was studied in 147 datasets from a cohort ranging in age from 19 to 89 y. Three fitting approaches were used to evaluate the macromolecular content: (1) a macromolecular resonances model developed for this study; (2) LCModel-simulated macromolecules; and (3) a combination of measured and LCModel-simulated macromolecules. The effect of age on the macromolecular content was investigated by considering age both as a continuous variable (i.e., linear regressions) and as a categorical variable (i.e., multiple comparisons among sub-groups obtained by stratifying data according to age by decade). RESULTS: While weak age-related effects were observed for macromolecular peaks at ˜0.9 (MM09), ˜1.2 (MM12), and ˜1.4 (MM14) ppm, moderate to strong effects were observed for peaks at ˜1.7 (MM17), and ˜2.0 (MM20) ppm. Significantly higher MM17 and MM20 content started from 30 to 40 y of age, while for MM09, MM12, and MM14, significantly higher content started from 60 to 70 y of age. CONCLUSIONS: Our findings provide insights into age-related differences in macromolecular contents and strengthen the necessity of using age-matched measured macromolecules during quantification.

• Keywords
• LCModel, MRS, aging, macromolecules, ultra‐high field,
• MeSH
• Gyrus Cinguli diagnostic imaging   chemistry   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Macromolecular Substances * chemistry   MeSH
• Young Adult MeSH
• Brain diagnostic imaging   metabolism   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Aging * MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Macromolecular Substances * MeSH

Magnetic resonance spectroscopic imaging (MRSI) involves a huge number of spectra to be processed and analyzed. Several tools enabling MRSI data processing have been developed and widely used. However, the processing programs primarily focus on sophisticated spectra processing and offer limited support for the analysis of the calculated spectroscopic maps. In this paper the jSIPRO (java Spectroscopic Imaging PROcessing) program is presented, which is a java-based graphical interface enabling post-processing, viewing, analysis and result reporting of MRSI data. Interactive graphical processing as well as protocol controlled batch processing are available in jSIPRO. jSIPRO does not contain a built-in fitting program. Instead, it makes use of fitting programs from third parties and manages the data flows. Currently, automatic spectra processing using LCModel, TARQUIN and jMRUI programs are supported. Concentration and error values, fitted spectra, metabolite images and various parametric maps can be viewed for each calculated dataset. Metabolite images can be exported in the DICOM format either for archiving purposes or for the use in neurosurgery navigation systems.

• Keywords
• DICOM export, LCModel, Metabolite images, Spectra processing, Spectroscopic imaging, TARQUIN, jMRUI,
• MeSH
• Electronic Data Processing statistics & numerical data   MeSH
• Fourier Analysis MeSH
• Functional Neuroimaging statistics & numerical data   MeSH
• Humans MeSH
• Magnetic Resonance Imaging statistics & numerical data   MeSH
• Brain metabolism   pathology   MeSH
• Programming Languages MeSH
• Software * MeSH
• Imaging, Three-Dimensional MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

PURPOSE: Reliable detection and fitting of macromolecules (MM) are crucial for accurate quantification of brain short-echo time (TE) 1 H-MR spectra. An experimentally acquired single MM spectrum is commonly used. Higher spectral resolution at ultra-high field (UHF) led to increased interest in using a parametrized MM spectrum together with flexible spline baselines to address unpredicted spectroscopic components. Herein, we aimed to: (1) implement an advanced methodological approach for post-processing, fitting, and parametrization of 9.4T rat brain MM spectra; (2) assess the concomitant impact of the LCModel baseline and MM model (ie, single vs parametrized); and (3) estimate the apparent T2 relaxation times for seven MM components. METHODS: A single inversion recovery sequence combined with advanced AMARES prior knowledge was used to eliminate the metabolite residuals, fit, and parametrize 10 MM components directly from 9.4T rat brain in vivo 1 H-MR spectra at different TEs. Monte Carlo simulations were also used to assess the concomitant influence of parametrized MM and DKNTMN parameter in LCModel. RESULTS: A very stiff baseline (DKNTMN ≥ 1 ppm) in combination with a single MM spectrum led to deviations in metabolite concentrations. For some metabolites the parametrized MM showed deviations from the ground truth for all DKNTMN values. Adding prior knowledge on parametrized MM improved MM and metabolite quantification. The apparent T2 ranged between 12 and 24 ms for seven MM peaks. CONCLUSION: Moderate flexibility in the spline baseline was required for reliable quantification of real/experimental spectra based on in vivo and Monte Carlo data. Prior knowledge on parametrized MM improved MM and metabolite quantification.

• Keywords
• 1H-MRS, UHF, baseline, fitting, macromolecules, parametrization, rat brain, relaxation times,
• MeSH
• Rats MeSH
• Macromolecular Substances metabolism   MeSH
• Brain Chemistry * MeSH
• Brain * diagnostic imaging   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Macromolecular Substances MeSH

The aim of the study was to analyze the lateralizing value of proton magnetic resonance spectroscopy ((1)H MRS) in histopathologically different subgroups of mesial temporal lobe epilepsies (MTLE) and to correlate results with clinical, MRI and seizure outcome data. A group of 35 patients who underwent resective epilepsy surgery was retrospectively studied. Hippocampal (1)H MR spectra were evaluated. Metabolite concentrations were obtained using LCModel and NAA/Cr, NAA/Cho, NAA/(Cr+Cho), Cho/Cr ratios and coefficients of asymmetry were calculated. MRI correctly lateralized 89% of subjects and (1)H MRS 83%. MRI together with (1)H MRS correctly lateralized 100% of patients. Nineteen subjects had "classical" hippocampal sclerosis (HS), whereas the remaining 16 patients had "mild" HS. Nineteen patients had histopathologically proven malformation of cortical development (MCD) in the temporal pole; 16 subjects had only HS. No difference in (1)H MRS findings was found between patients in different histopathological subgroups of MTLE. Our results support the hypothesis that (1)H MRS abnormalities do not directly reflect histopathological changes in MTLE patients. Subjects with non-lateralized (1)H MRS abnormalities did not have a worse postoperative seizure outcome. We found no significant impact of contralateral (1)H MRS abnormality on post-surgical seizure outcome.

• MeSH
• Adult MeSH
• Electroencephalography methods   MeSH
• Epilepsy, Temporal Lobe diagnosis   pathology   surgery   MeSH
• Hippocampus pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Adolescent MeSH
• Reproducibility of Results MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

OBJECTIVE: The effects of aging, magnetic field and the voxel localization on measured concentrations of citrate (Cit), creatine (Cr), cholines (Cho) and polyamines (PA) in a healthy prostate were evaluated. MATERIALS AND METHODS: 36 examinations at both 1.5T and 3T imagers of 52 healthy subjects aged 19-71 years were performed with PRESS 3D-CSI sequences (TE = 120 and 145 ms). Concentrations in laboratory units and their ratios to citrate were calculated using the LCModel technique. Absolute concentrations were also obtained after the application of correction coefficients. Statistical analysis was performed using a robust linear mixed effects model. RESULTS: Significant effects of aging, the magnetic field strength and the voxel position in central (CZ) or peripheral (PZ) zones on all measured metabolites were found. The concentrations (mmol/kg wet tissue) including prediction intervals in a range of 20-70 years were found: Cit: 7.9-17.2; Cho: 1.4-1.7; Cr: 2.8-2.5; PA (as spermine): 0.6-2.1 at 3T in CZ. In PZ, the concentrations were higher by about 10 % as compared to CZ. CONCLUSION: Increasing citrate and spermine concentrations with age are significant and correlate well with a recently described increase of zinc in the prostate. These findings should be considered in decision-making if the values obtained from a subject are in the range of control values.

• Keywords
• 1H MRS, Aging, Choline, Citrate, Creatine, Polyamines, Prostate, Spermine,
• MeSH
• Choline chemistry   MeSH
• Citrates chemistry   MeSH
• Adult MeSH
• Creatinine chemistry   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy * MeSH
• Magnetic Fields MeSH
• Young Adult MeSH
• Prostatic Neoplasms diagnostic imaging   metabolism   pathology   MeSH
• Polyamines chemistry   MeSH
• Prostate diagnostic imaging   metabolism   MeSH
• Decision Making MeSH
• Aged MeSH
• Spermine analysis   MeSH
• Zinc analysis   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Choline MeSH
• Citrates MeSH
• Creatinine MeSH
• Polyamines MeSH
• Spermine MeSH
• Zinc MeSH

PURPOSE: To determine the test-retest reproducibility of neurochemical concentrations obtained with a highly optimized, short-echo, single-voxel proton MR spectroscopy (MRS) pulse sequence at 3T and 7T using state-of-the-art hardware. METHODS: A semi-LASER sequence (echo time = 26-28 ms) was used to acquire spectra from the posterior cingulate and cerebellum at 3T and 7T from six healthy volunteers who were scanned four times weekly on both scanners. Spectra were quantified with LCModel. RESULTS: More neurochemicals were quantified with mean Cramér-Rao lower bounds (CRLBs) ≤20% at 7T than at 3T despite comparable frequency-domain signal-to-noise ratio. Whereas CRLBs were lower at 7T (P < 0.05), between-session coefficients of variance (CVs) were comparable at the two fields with 64 transients. Five metabolites were quantified with between-session CVs ≤5% at both fields. Analysis of subspectra showed that a minimum achievable CV was reached with a lower number of transients at 7T for multiple metabolites and that between-session CVs were lower at 7T than at 3T with fewer than 64 transients. CONCLUSION: State-of-the-art MRS methodology allows excellent reproducibility for many metabolites with 5-min data averaging on clinical 3T hardware. Sensitivity and resolution advantages at 7T are important for weakly represented metabolites, short acquisitions, and small volumes of interest. Magn Reson Med 76:1083-1091, 2016. © 2015 Wiley Periodicals, Inc.

• Keywords
• 3 Tesla, 7 Tesla, coefficient of variation, spectroscopy, test-retest reproducibility,
• MeSH
• Algorithms * MeSH
• Adult MeSH
• Image Interpretation, Computer-Assisted methods   MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Resonance Imaging instrumentation   methods   MeSH
• Molecular Imaging instrumentation   methods   MeSH
• Brain anatomy & histology   metabolism   MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Tissue Distribution MeSH
• Image Enhancement methods   MeSH
• Imaging, Three-Dimensional methods   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Comparative Study MeSH
• Validation Study MeSH