OBJECTIVE: Many patients with long COVID experience neurological and psychological symptoms. Signal abnormalities on MR images in the corpus callosum have been reported. Knowledge about the metabolic profile in the splenium of the corpus callosum (CCS) may contribute to a better understanding of the pathophysiology of long COVID. MATERIALS AND METHODS: Eighty-one subjects underwent proton MR spectroscopy examination. The metabolic concentrations of total N-acetylaspartate (NAA), choline-containing compounds (Cho), total creatine (Cr), myo-inositol (mI), and NAA/Cho in the CCS were statistically compared in the group of patients containing 58 subjects with positive IgG COVID-19 antibodies or positive SARS-CoV-2 qPCR test at least two months before the MR and the group of healthy controls containing 23 subjects with negative IgG antibodies. RESULTS: An age-dependent effect of SARS-CoV-2 on Cho concentrations in the CCS has been observed. Considering the subjective threshold of age = 40 years, older patients showed significantly increased Cho concentrations in the CCS than older healthy controls (p = 0.02). NAA, Cr, and mI were unchanged. All metabolite concentrations in the CCS of younger post-COVID-19 patients remained unaffected by SARS-CoV-2. Cho did not show any difference between symptomatic and asymptomatic patients (p = 0.91). DISCUSSION: Our results suggest that SARS-CoV-2 disproportionately increases Cho concentration in the CCS among older post-COVID-19 patients compared to younger ones. The observed changes in Cho may be related to the microstructural reorganization in the CCS also reported in diffusion measurements rather than increased membrane turnover. These changes do not seem to be related to neuropsychological problems of the post-COVID-19 patients. Further metabolic studies are recommended to confirm these observations.

• Klíčová slova
• COVID-19, Metabolism, Proton MR spectroscopy, The splenium of the corpus callosum,
• MeSH
• cholin * metabolismus   MeSH
• corpus callosum * diagnostické zobrazování   metabolismus   MeSH
• COVID-19 * diagnostické zobrazování   metabolismus   MeSH
• dospělí MeSH
• inositol metabolismus   MeSH
• kreatin * metabolismus   MeSH
• kyselina asparagová * analogy a deriváty   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• protonová magnetická rezonanční spektroskopie * metody   MeSH
• SARS-CoV-2 * MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cholin * MeSH
• inositol MeSH
• kreatin * MeSH
• kyselina asparagová * MeSH
• N-acetylaspartate MeSH Prohlížeč

INTRODUCTION: Altered subjective visual sensitivity manifests as feelings of discomfort or overload elicited by intense and irritative visual stimuli. This can result in a host of visual aberrations including visual distortions, elementary visual hallucinations and visceral responses like dizziness and nausea, collectively referred to as "pattern glare." Current knowledge of the underlying neural mechanisms has focused on overall excitability of the visual cortex, but the individual contribution of excitatory and inhibitory systems has not yet been quantified. METHODS: In this study, we focus on the role of glutamate and γ-aminobutyric acid (GABA) as potential mediators of individual differences in subjective visual sensitivity, measured by a computerized Pattern Glare Test-a series of monochromatic square-wave gratings with three different spatial frequencies, while controlling for psychological variables related to sensory sensitivity with multiple questionnaires. Resting neurotransmitter concentrations in primary visual cortex (V1) and right anterior insula were studied in 160 healthy participants using magnetic resonance spectroscopy. RESULTS: Data showed significant differences in the perception of visual distortions (VD) and comfort scores between men and women, with women generally reporting more VD, and therefore the modulatory effect of sex was considered in a further examination. A general linear model analysis showed a negative effect of occipital glutamate on a number of reported visual distortions, but also a significant role of several background psychological traits. When assessing comfort scores in women, an important intervening variable was the menstrual cycle. DISCUSSION: Our findings do not support that baseline neurotransmitter levels have a significant role in overreactivity to aversive stimuli in neurotypical population. However, we demonstrated that biological sex can have a significant impact on subjective responses. Based on this additional finding, we suggest that future studies investigate aversive visual stimuli while examining the role of biological sex.

• Klíčová slova
• GABA, Pattern Glare Test, cortical excitability, glutamate, magnetic resonance spectroscopy, visual discomfort,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The main aim of the present study is to determine the role of metabolites observed using proton magnetic resonance spectroscopy (1H-MRS) in obsessive-compulsive disorder (OCD). As the literature describing biochemical changes in OCD yields conflicting results, we focused on accurate metabolite quantification of total N-acetyl aspartate (tNAA), total creatine (tCr), total choline-containing compounds (tCh), and myo-inositol (mI) in the anterior cingulate cortex (ACC) to capture the small metabolic changes between OCD patients and controls and between OCD patients with and without medication. METHODS: In total 46 patients with OCD and 46 healthy controls (HC) matched for age and sex were included in the study. The severity of symptoms in the OCD was evaluated on the day of magnetic resonance imaging (MRI) using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Subjects underwent 1H-MRS from the pregenual ACC (pgACC) region to calculate concentrations of tNAA, tCr, tCho, and mI. Twenty-eight OCD and 28 HC subjects were included in the statistical analysis. We compared differences between groups for all selected metabolites and in OCD patients we analyzed the relationship between metabolite levels and symptom severity, medication status, age, and the duration of illness. RESULTS: Significant decreases in tCr (U = 253.00, p = 0.022) and mI (U = 197.00, p = 0.001) in the pgACC were observed in the OCD group. No statistically significant differences were found in tNAA and tCho levels; however, tCho revealed a trend towards lower concentrations in OCD patients (U = 278.00, p = 0.062). Metabolic concentrations showed no significant correlations with the age and duration of illness. The correlation statistics found a significant negative correlation between tCr levels and YBOCS compulsions subscale (cor = -0.380, p = 0.046). tCho and YBOCS compulsions subscale showed a trend towards a negative correlation (cor = -0.351, p = 0.067). Analysis of subgroups with or without medication showed no differences. CONCLUSIONS: Patients with OCD present metabolic disruption in the pgACC. The decrease in tCr shows an important relationship with OCD symptomatology. tCr as a marker of cerebral bioenergetics may also be considered as a biomarker of the severity of compulsions. The study failed to prove that metabolic changes correlate with the medication status or the duration of illness. It seems that a disruption in the balance between these metabolites and their transmission may play a role in the pathophysiology of OCD.

• Klíčová slova
• Choline-containing compounds, Creatine, Magnetic resonance spectroscopy, Myo-inositol, N-acetyl aspartate, Obsessive-compulsive disorder,
• MeSH
• cingulární gyrus diagnostické zobrazování   metabolismus   MeSH
• glutamin * metabolismus   MeSH
• inositol metabolismus   terapeutické užití   MeSH
• kreatin metabolismus   terapeutické užití   MeSH
• kyselina asparagová metabolismus   terapeutické užití   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• obsedantně kompulzivní porucha * diagnóza   MeSH
• protonová magnetická rezonanční spektroskopie metody   MeSH
• receptory antigenů T-buněk metabolismus   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glutamin * MeSH
• inositol MeSH
• kreatin MeSH
• kyselina asparagová MeSH
• receptory antigenů T-buněk MeSH

INTRODUCTION: Loss of consciousness (LOC) is used as a diagnostic feature of mild traumatic brain injury (MTBI). However, only 10% of concussions result in LOC. There are only a limited number of in-vivo studies dealing with unconsciousness and structural and functional integrity of the brainstem in patients with MTBI. The aim of our pilot study was to assess the sensitivity of proton magnetic resonance spectroscopy (1H-MRS) to detect metabolic changes in the brainstem in patients after MTBI with unconscioussness. METHODS: Twenty-four patients (12 with LOC, and 12 without LOC) within 3 days of MTBI and 19 healthy controls were examined. All subjects underwent single-voxel 1H-MRS examination of the upper brainstem. Spectra were evaluated using LCModel software. Ratios of total N-acetylaspartate (tNAA), total choline-containing compounds (tCho) and glutamate plus glutamine (Glx) to total creatine (tCre) were used for calculations. RESULTS: We found a significant decrease in tNAA/tCre and tCho/tCre ratios in the patient group with LOC when compared with the control group of healthy volunteers (P=0.002 and P=0.041, respectively), and a significant decrease in the tNAA/tCre ratio in the LOC group when compared with patients without LOC (P=0.04). Other metabolite ratios in the brainstem did not show any significant group differences. CONCLUSION: Our findings indicate that decrease of tNAA/tCre ratio in the upper brainstem using single-voxel 1H-MRS may provide a potential biomarker for MTBI associated with LOC.

• Klíčová slova
• concussion, loss of consciousness, magnetic resonance spectroscopy, mild traumatic brain injury,
• MeSH
• bezvědomí etiologie   MeSH
• komoce mozku * komplikace   diagnostické zobrazování   metabolismus   MeSH
• lidé MeSH
• mozkový kmen diagnostické zobrazování   metabolismus   MeSH
• pilotní projekty MeSH
• protonová magnetická rezonanční spektroskopie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články 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.

• Klíčová slova
• 1H-MRS, UHF, baseline, fitting, macromolecules, parametrization, rat brain, relaxation times,
• 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
• Názvy látek
• makromolekulární látky MeSH

Increased hepatic fat content (HFC) is a hallmark of non-alcoholic fatty liver (NAFL) disease, a common condition in liver transplant recipients. Proton MR spectroscopy (1H MRS) and MR imaging-based proton density fat fraction as the only diagnosis modality enable precise non-invasive measurement of HFC and, also, fatty acid profiles in vivo. Using 1H MRS at 3T, we examined 47 liver transplantation candidates and 101 liver graft recipients. A point-resolved spectroscopy sequence was used to calculate the steatosis grade along with the saturated, unsaturated and polyunsaturated fractions of fatty acids in the liver. The steatosis grade measured by MRS was compared with the histological steatosis grade. HFC, represented by fat fraction values, is adept at distinguishing non-alcoholic steatohepatitis (NASH), NAFL and non-steatotic liver transplant patients. Relative hepatic lipid saturation increases while unsaturation decreases in response to increased HFC. Additionally, relative hepatic lipid saturation increases while unsaturation and polyunsaturation both decrease in liver recipients with histologically proven post-transplant NASH or NAFL compared to non-steatotic patients. HFC, measured by in vivo 1H MRS, correlated well with histological results. 1H MRS is a simple and fast method for in vivo analysis of HFC and its composition. It provides non-invasive support for NAFL and NASH diagnoses.

• Klíčová slova
• MR spectroscopy, NAFLD, NASH, lipid profile, lipid saturation, liver, magnetic resonance, steatosis, transplantation,
• Publikační typ
• časopisecké články MeSH

The accurate identification of glioblastoma progression remains an unmet clinical need. The aim of this prospective single-institutional study is to determine and validate thresholds for the main metabolite concentrations obtained by MR spectroscopy (MRS) and the values of the apparent diffusion coefficient (ADC) to enable distinguishing tumor recurrence from pseudoprogression. Thirty-nine patients after the standard treatment of a glioblastoma underwent advanced imaging by MRS and ADC at the time of suspected recurrence - median time to progression was 6.7 months. The highest significant sensitivity and specificity to call the glioblastoma recurrence was observed for the total choline (tCho) to total N-acetylaspartate (tNAA) concentration ratio with the threshold ≥ 1.3 (sensitivity 100.0% and specificity 94.7%). The ADCmean value higher than 1313 × 10(- 6) mm(2)/s was associated with the pseudoprogression (sensitivity 98.3%, specificity 100.0%). The combination of MRS focused on the tCho/tNAA concentration ratio and the ADCmean value represents imaging methods applicable to early non-invasive differentiation between a glioblastoma recurrence and a pseudoprogression. However, the institutional definition and validation of thresholds for differential diagnostics is needed for the elimination of setup errors before implementation of these multimodal imaging techniques into clinical practice, as well as into clinical trials.

• Klíčová slova
• Apparent diffusion coefficient, Glioma, Imaging sensitivity, Recurrence, Spectroscopy,
• MeSH
• cholin metabolismus   MeSH
• difuzní magnetická rezonance * MeSH
• dospělí MeSH
• glioblastom diagnostické zobrazování   MeSH
• kohortové studie MeSH
• kyselina asparagová analogy a deriváty   metabolismus   MeSH
• kyselina glutamová metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie * MeSH
• nádory mozku diagnostické zobrazování   MeSH
• neparametrická statistika MeSH
• počítačové zpracování obrazu MeSH
• ROC křivka MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cholin MeSH
• kyselina asparagová MeSH
• kyselina glutamová MeSH
• N-acetylaspartate MeSH Prohlížeč

BACKGROUND: The hippocampus is considered as the main radiosensitive brain structure responsible for postradiotherapy cognitive decline. We prospectively assessed correlation of memory change to hippocampal N-acetylaspartate (h-tNAA) concentration, a neuronal density and viability marker, by (1)H-MR spectroscopy focused on the hippocampus. METHODS: Patients with brain metastases underwent whole brain radiotherapy (WBRT) to a dose of 30 Gy in ten fractions daily. Pre-radiotherapy (1)H-MR spectroscopy focused on the h-tNAA concentration and memory testing was performed. Memory was evaluated by Auditory Verbal Learning Test (AVLT) and Brief Visuospatial Memory Test-Revised (BVMT-R). Total recall, recognition and delayed recall were reported. The both investigation procedures were repeated 4 months after WBRT and the h-tNAA and memory changes were correlated. RESULTS: Of the 20 patients, ten passed whole protocol. The h-tNAA concentration significantly decreased from pre-WBRT 8.9, 8.86 and 8.88 [mM] in the right, left and both hippocampi to 7.16, 7.65 and 7.4 after WBRT, respectively. In the memory tests a significant decrease was observed in AVLT total-recall, BVMT-R total-recall and BVMT-R delayed-recall. Weak to moderate correlations were observed between left h-tNAA and AVLT recognition and all BVMT-R subtests and between the right h-tNAA and AVLT total-recall. CONCLUSIONS: A significant decrease in h-tNAA after WBRT was proven by (1)H-MR spectroscopy as a feasible method for the in vivo investigation of radiation injury. Continuing patient recruitment focusing on other cognitive tests and metabolites is needed.

• MeSH
• biologické markery analýza   MeSH
• hipokampus účinky záření   MeSH
• Kaplanův-Meierův odhad MeSH
• kognitivní poruchy diagnóza   etiologie   MeSH
• kraniální ozáření škodlivé účinky   MeSH
• kyselina asparagová analogy a deriváty   analýza   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• nádory mozku mortalita   radioterapie   sekundární   MeSH
• neuropsychologické testy MeSH
• paměť MeSH
• protony MeSH
• radiační poranění diagnóza   MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• kyselina asparagová MeSH
• N-acetylaspartate MeSH Prohlížeč
• protony MeSH

OBJECTIVE: To prospectively determine institutional cut-off values of apparent diffusion coefficients (ADCs) and concentration of tissue metabolites measured by MR spectroscopy (MRS) for early differentiation between glioblastoma (GBM) relapse and treatment-related changes after standard treatment. MATERIALS AND METHODS: Twenty-four GBM patients who received gross total resection and standard adjuvant therapy underwent MRI examination focusing on the enhancing region suspected of tumor recurrence. ADC maps, concentrations of N-acetylaspartate, choline, creatine, lipids, and lactate, and metabolite ratios were determined. Final diagnosis as determined by biopsy or follow-up imaging was correlated to the results of advanced MRI findings. RESULTS: Eighteen (75%) and 6 (25%) patients developed tumor recurrence and pseudoprogression, respectively. Mean time to radiographic progression from the end of chemoradiotherapy was 5.8 ± 5.6 months. Significant differences in ADC and MRS data were observed between those with progression and pseudoprogression. Recurrence was characterized by N-acetylaspartate ≤ 1.5 mM, choline/N-acetylaspartate ≥ 1.4 (sensitivity 100%, specificity 91.7%), N-acetylaspartate/creatine ≤ 0.7, and ADC ≤ 1300 × 10(-6) mm(2)/s (sensitivity 100%, specificity 100%). CONCLUSION: Institutional validation of cut-off values obtained from advanced MRI methods is warranted not only for diagnosis of GBM recurrence, but also as enrollment criteria in salvage clinical trials and for reporting of outcomes of initial treatment.

• MeSH
• chemoradioterapie metody   MeSH
• dakarbazin analogy a deriváty   terapeutické užití   MeSH
• glioblastom diagnóza   metabolismus   terapie   MeSH
• hodnocení výsledků zdravotní péče metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru diagnóza   metabolismus   prevence a kontrola   MeSH
• molekulární zobrazování metody   MeSH
• nádorové biomarkery metabolismus   MeSH
• nádory mozku diagnóza   metabolismus   terapie   MeSH
• následné studie MeSH
• prognóza MeSH
• protonová magnetická rezonanční spektroskopie metody   MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• temozolomid MeSH
• výsledek terapie MeSH
• zobrazování difuzních tenzorů MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dakarbazin MeSH
• nádorové biomarkery MeSH
• temozolomid MeSH