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%. Copyright 2006 Wiley-Liss, Inc.

• MeSH
• algoritmy MeSH
• analýza rozptylu MeSH
• biologické modely MeSH
• časové faktory MeSH
• diabetes mellitus metabolismus   MeSH
• dospělí MeSH
• financování organizované MeSH
• interpretace obrazu počítačem MeSH
• kosterní svaly metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetismus MeSH
• metabolismus lipidů fyziologie   MeSH
• referenční hodnoty MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• Publikační typ
• klinické zkoušky kontrolované MeSH
• srovnávací studie MeSH

• MeSH
• fantomy radiodiagnostické MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie MeSH
• mozek metabolismus   MeSH
• Check Tag
• lidé MeSH

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.

• MeSH
• adenosindifosfát metabolismus   MeSH
• adenosintrifosfát metabolismus   MeSH
• fosfatidylcholiny metabolismus   MeSH
• fosfatidylethanolaminy metabolismus   MeSH
• fosfáty metabolismus   MeSH
• fosfor metabolismus   MeSH
• játra metabolismus   MeSH
• kosterní svaly metabolismus   MeSH
• lidé MeSH
• nukleární magnetická rezonance biomolekulární * MeSH
• pilotní projekty MeSH
• software * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH

Protonová MR spektroskopie byla použita k výpočtu absolutních a relativních koncentrací vybraných sloučenin v mozku. Cílem studie bylo porovnání možností dvóu celotělových MR tomografů a nezávislých metod používaných pro výpočet absolutních a relativních koncentrací vybraných metabolitů z 1H MR spekter. Výsledky ukazují, že hodnoty molárních koncentrací v bílé hmotě získané technikou externího standardu (vody) jsou pro NAA = 11,4 mmoH, Cr/PCr = 7,3 mmol/1 a Cho = 1,6 mmol/1 při TE = 40 ms (sekvence STEAM) a jsou srovnatelné s výsledky měřenými s TE = 270 ms. Tyto hodnoty jsou vyšší než hodnoty získané metodou externích standardů zpracovaných metodou LCModel (NAA, Cr/PCr, Cho = 7,4,3,5 a 1,4 mmol/1) při TE = 10 ms (STEAM). Rozdíl v absolutních hodnotách je dán rozdílným způsobem vyhodnocování spekter, který v případě LCModelu určuje příspěvky intenzit signálů všech uvažovaných sloučenin ve spektru. Metoda LCModel poskytuje především hodnoty relativní¬ ho zastoupení celé řady metabolitů (glutamin, glutamát, laktát, inozitoly a další).

Proton MR spectroscopy was used to calculate absolute and relative concentrations of selected compounds in the brain. The objective was to compare possibUities of two whole-body MR tomographs and independent methods used for the calculation of absolute and relative concentrations of selected metabolites from 1H MR spectra. The results indicate that the values of molar concentrations in the white matter obtained by the technique of an external standard (water) are for NAA = 11.4 mmoUl, Cr/PCr ^ 7.3 mmol/l and Cho = 1.6 mmol/1 at TE = 40 ms (sequence STEAM) and are comparable with results assessed at TE =270 ms. These values are higher than values obtained by the method of external standards elaborated by the method LCModel (NAA, Cr/PCr, Cho = 7.3, 3.5 and 1.4 mmol/l) at TE = 10 ms (STEAM). The difference in absolute values is due to the different mode of evaluation of spectra which in case of the LCModel determines the contributions of signal intensities of all compounds assumed in the spectrum. The method of the LCModel provides above all values of the ratio of a number of metabolites (glutamine, glutamate, lactate, inositols and others).

• MeSH
• glutamáty metabolismus   MeSH
• glutamin metabolismus   MeSH
• inositol metabolismus   MeSH
• laktáty metabolismus   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   přístrojové vybavení   MeSH
• magnetická rezonanční tomografie MeSH
• mozek metabolismus   MeSH
• Check Tag
• lidé MeSH

Cíl: Porovnat spektroskopické metody stanovení steatózy sekvencemi PRESS, STEAM a HISTO na 3T tomografech TRIO a VIDA. Metodika: Byla naměřena 1H MR spektra jater dobrovolníků na 3T tomografech Siemens TRIO a VIDA (45/25 subjektů) sekvencemi PRESS s TE = 30/33 ms, STEAM s TE = 20/33 ms a metodou HISTO s TE = 12-72 ms. Stejné sekvence byly použity pro stanovení T2 lipidů a vody. Spektra byla zpracována programem LCModel. Frakční (FF) a objemové (HFC) zlomky (%) byly korigovány individuálními a průměrnými hodnotami relaxačních časů T2. Analýza výsledků byla provedena korelační, regresní a Bland-Altmanovou metodou. Výsledky: Relaxační časy T2 snižují hodnoty parametrů FF a HFC až o cca 47 % při použití nominálních T2. Regresní analýza a Bland-Altmanovy grafy ukazují, že parametry získané technikami PRESS, STEAM a HISTO s TE 20 a 33 ms na VIDA jsou srovnatelné. Byly změřeny hodnoty T2 lipidů mezi 45-53 ms a T2 vody mezi 24-31 ms. Byly stanoveny limitní hodnoty FF pro určení stupně steatózy u transplantovaných pacientů v těchto rozsazích: S0: < 0,8 %; S1: 0,81-6,2 %; S2: 6,21-16,5 %; S3: > 16,5 %. Závěr: Získané hodnoty FF a HFC jsou citlivé na T2 korekce a použití průměrných hodnot T2 dává vyšší hodnoty parametrů FF a HFC. Bland-Altmanovy grafy ukazují na dobrou shodu metod STEAM, PRESS a HISTO. Limitní hodnoty pro stanovení stupně steatózy u transplantovaných pacientů z výsledků HISTO metody jsou v rozmezí literárních hodnot.

Aim: To compare MR spectroscopic methods for steatosis determination by PRESS, STEAM and HISTO sequences on 3T TRIO and VIDA tomographs. Method: 1H MR spectra of the liver of volunteers were measured on 3T tomographs Siemens TRIO and VIDA (45/25 subjects). The sequences PRESS with TE = 30/33 ms, STEAM with TE = 20/33 ms and the HISTO method with TE = 12-72 ms were used. The same sequences were used to determine T2 of lipids and water. The spectra were processed using the LCModel method. Fractional (FF) and volume (HFC) fractions (%) were corrected for individual and mean T2 values. Correlation, regression and Bland-Altman data analyses were performed. Results: Relaxation times T2 reduce FF and HFC values by up to approx. 47%. Regression analysis and Bland-Altman graphs show that the parameters obtained by PRESS, STEAM and HISTO techniques with short TE are comparable on VIDA. Mean T2 values of lipids between 45 and 53 ms and T2 of water between 24 and 31 ms were measured. HISTO FF cut-off values for the degree of steatosis in transplant patients were set in the following ranges: S0: < 0.8%; S1: 0.81-6.2%; S2: 6.21-16.5%; S3: > 16.5%. Conclusion: The obtained FF and HFC values are sensitive to T2 corrections. Bland-Altman´s graphs indicate good agreement among STEAM, PRESS and HISTO methods. Limit values for the steatosis degree in transplant patients from the result of the HISTO method agree with literature values.

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.

• MeSH
• cingulární gyrus diagnostické zobrazování   chemie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie metody   MeSH
• makromolekulární látky * chemie   MeSH
• mladý dospělý MeSH
• mozek diagnostické zobrazování   metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• stárnutí * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural 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.

• MeSH
• krysa rodu rattus MeSH
• makromolekulární látky metabolismus   MeSH
• mozek - chemie * MeSH
• mozek * diagnostické zobrazování   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural 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.

• MeSH
• automatizované zpracování dat statistika a číselné údaje   MeSH
• Fourierova analýza MeSH
• funkční zobrazování neurálních procesů statistika a číselné údaje   MeSH
• lidé MeSH
• magnetická rezonanční tomografie statistika a číselné údaje   MeSH
• mozek metabolismus   patologie   MeSH
• programovací jazyk MeSH
• software * MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem 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
• dospělí MeSH
• elektroencefalografie metody   MeSH
• epilepsie temporálního laloku diagnóza   chirurgie   patologie   MeSH
• hipokampus patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie metody   MeSH
• mladiství MeSH
• reprodukovatelnost výsledků MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem 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.

• MeSH
• cholin chemie   MeSH
• citráty chemie   MeSH
• dospělí MeSH
• kreatinin chemie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie * MeSH
• magnetické pole MeSH
• mladý dospělý MeSH
• nádory prostaty diagnostické zobrazování   metabolismus   patologie   MeSH
• polyaminy chemie   MeSH
• prostata diagnostické zobrazování   metabolismus   MeSH
• rozhodování MeSH
• senioři MeSH
• spermin analýza   MeSH
• zinek analýza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH